Printing and Saving Instructions - Technical Learning College

WATER TREATMENT 303 

CONTINUING EDUCATION 

PROFESSIONAL DEVELOPMENT COURSE

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Printing and Saving Instructions 

The best thing to do is to download this pdf document to your 

computer desktop and open it with Adobe Acrobat reader. 

Abode Acrobat reader is a free computer software program and you 

can find it at Abode Acrobat’s website. 

You can complete the course by viewing the course materials on your 

computer or you can print it out. We give you permission to print this 

document. 

Printing Instructions: If you are going to print this document, this 

document is designed to be printed double-sided or duplexed but can 

be single-sided. 

This course booklet does not have the assignment. Please visit our 

website and download the assignment also. 

Internet Link to Assignment… 

http://www.abctlc.com/PDF/Treatment303ASS.pdf 

State Approval Listing Link, check to see if your State accepts or has 

pre-approved this course. Not all States are listed. Not all courses 

are listed. If the course is not accepted for CEU credit, we will give 

you the course free if you ask your State to accept it for credit. 

Professional Engineers: Most states will accept our courses for 

credit but we do not officially list the States or Agencies acceptance 

or approvals. 

State Approval Listing URL… 

http://www.tlch2o.com/PDF/CEU%20State%20Approvals.pdf 

You can obtain a printed version from TLC for an additional $79.95 

plus shipping charges. 

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We have taught this course to over 5,000 students in a conventional classroom 

setting. Call and schedule a class at your facility or utilize the distance learning 

course to obtain your CEUs. 

Copyright Notice 

©2010 Technical Learning College (TLC). No part of this work may be reproduced or distributed in any form 

or by any means without TLC’s prior written approval. Permission has been sought for all images and text 

where we believe copyright exists and where the copyright holder is traceable and contactable. All material 

not credited or acknowledged is the copyright of TLC. The information in this manual is intended for 

educational purposes only. Most unaccredited photographs have been taken by TLC instructors or TLC 

students. We would be pleased to hear from any copyright holder and will make good on your work if any 

unintentional copyright infringements were made upon these issues being brought to our attention. 

Every possible effort is made to ensure all information provided in this course is accurate. All written, 

graphic, photographic or other material is provided for information only. Therefore, TLC accepts no 

responsibility or liability whatsoever for the application or misuse of any information included herein. 

Requests for permission to make copies should be made to the following address: 

TLC 

PO Box 420 

Payson, AZ 85547-0420 

Information in this document is subject to change without notice. TLC is not liable for errors or omissions 

appearing in this document. 

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Contributing Editors 

Joseph Camerata has a BS in Management with honors (magna cum laude). He retired 

as a Chemist in 2006 having worked in the field of chemical, environmental, and 

industrial hygiene sampling and analysis for 40 years. He has been a professional 

presenter at an EPA analytical conference at the Biosphere in Arizona and a 

presenter at an AWWA conference in Mesa, Arizona. He also taught safety classes at 

the Honeywell and City of Phoenix, and is a motivational/inspirational speaker nationally 

and internationally. 

Eric Pearce S.M.E., chemistry and biological review. 

Pete Greer S.M.E., retired biology instructor. 

Jack White, Environmental, Health, Safety Expert, City of Phoenix. Art Credits. 

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Technical Learning College’s Scope and Function 

Technical Learning College (TLC) offers affordable continuing education for today’s 

working professionals who need to maintain licenses or certifications. TLC holds 

approximately eighty different governmental approvals for granting of continuing education 

credit. 

TLC’s delivery method of continuing education can include traditional types of classroom 

lectures and distance-based courses or independent study. Most TLC’s distance based or 

independent study courses are offered in a print based format and you are welcome to 

examine this material on your computer with no obligation. Our courses are designed to be 

flexible and for you do finish the material on your leisure. Students can also receive course 

materials through the mail. The CEU course or e-manual will contain all your lessons, 

activities and assignments. Most CEU courses allow students to submit lessons using email 

or fax; however some courses require students to submit lessons by postal mail. (See 

the course description for more information.) Students have direct contact with their 

instructor—primarily by e-mail. TLC’s CEU courses may use such technologies as the 

World Wide Web, e-mail, CD-ROMs, videotapes and hard copies. (See the course 

description.) Make sure you have access to the necessary equipment before enrolling, i.e., 

printer, Microsoft Word and/or Adobe Acrobat Reader. Some courses may require 

proctored exams depending upon your state requirements. 

Flexible Learning 

At TLC, there are no scheduled online sessions you need contend with, nor are you 

required to participate in learning teams or groups designed for the "typical" younger 

campus based student. You will work at your own pace, completing assignments in time 

frames that work best for you. TLC's method of flexible individualized instruction is 

designed to provide each student the guidance and support needed for successful course 

completion. 

We will beat any other training competitor’s price for the same CEU material or classroom 

training. Student satisfaction is guaranteed. 

Course Structure 

TLC's online courses combine the best of online delivery and traditional university 

textbooks. Online you will find the course syllabus, course content, assignments, and 

online open book exams. This student friendly course design allows you the most flexibility 

in choosing when and where you will study. 

Classroom of One 

TLC Online offers you the best of both worlds. You learn on your own terms, on your own 

time, but you are never on your own. Once enrolled, you will be assigned a personal 

Student Service Representative who works with you on an individualized basis throughout 

your program of study. Course specific faculty members are assigned at the beginning of 

each course providing the academic support you need to successfully complete each 

course. 

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Satisfaction Guaranteed 

Our Iron-Clad, Risk-Free Guarantee ensures you will be another satisfied TLC student. 

We have many years of experience, dealing with thousands of students. We assure you, our 

customer satisfaction is second to none. This is one reason we have taught more than 20,000 

students. 

Our administrative staff is trained to provide the best customer service in town. Part of 

that training is knowing how to solve most problems on the spot with an exchange or 

refund. 

TLC Continuing Education Course Material Development 

Technical Learning College’s (TLC’s) continuing education course material development 

was based upon several factors; extensive academic research, advice from subject 

matter experts, data analysis, task analysis and training needs assessment process 

information gathered from other states. 

Rush Grading Service 

If you need this assignment graded and the results mailed to you within a 48-hour 

period, prepare to pay an additional rush service handling fee of $50.00. This fee 

may not cover postage costs. If you need this service, simply write RUSH on the top 

of your Registration Form. We will place you in the front of the grading and 

processing line. 

For security purposes, please fax or e-mail a copy of your driver’s license and always 

call us to confirm we’ve received your assignment and to confirm your identity. 

Thank you… 

Please fax or e-mail the answer key to TLC 

Western Campus Fax (928) 272-0747 Back-up Fax (928) 468-0675. 

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Water Treatment 303 CEU Training Course Description 

This distance learning CEU training course will examine various aspects of conventional water 

treatment methods, understanding pathogens, understand the disinfection process, and review 

federal drinking water rules and regulations. This course will also cover water treatment pumps 

and motors. This course was designed to provide continuing education credit to water 

treatment operators. 

Water Distribution, Well Drillers, Pump Installers, Water Treatment Operators, Water Treatment 

Specialists and Customer Service Personnel are welcomed to take this course. The target 

audience for this course is the person interested in working in a water treatment or distribution 

facility and/or wishing to maintain CEUs for a certification license or to learn how to do the job 

safely and effectively and/or to meet education needs for promotion. 

Task Analysis and Training Needs Assessments have been conducted to determine or set 

Needs-To-Know for this CEU course. The following is a listing of some of those who have 

conducted extensive valid studies from which TLC has based this program upon: the 

Environmental Protection Agency (EPA), the Arizona Department of Environmental Quality 

(ADEQ), the Texas Commission of Environmental Quality (TCEQ) and the American Boards of 

Certification (ABC). 

Final Examination for Credit 

Opportunity to pass the final comprehensive examination is limited to three attempts per course 

enrollment. 

Course Procedures for Registration and Support 

All of TLC’s correspondence courses have complete registration and support service offered. 

Delivery of service will include, e-mail, web site, telephone, fax and mail support. TLC will 

attempt immediate and prompt service. When a student registers for a distance or 

correspondence course, he or she is assigned a start date and an end date. It is the student’s 

responsibility to note dates for assignments and keep up with the course work. If a student falls 

behind, he/she must contact TLC and request an end date extension in order to complete the 

course. It is the prerogative of TLC to decide whether to grant the request. All students will be 

tracked by a unique assigned number. 

Instructions for Written Assignments 

The Water Treatment 303 CEU training course uses a multiple-choice and fill-in-the-blank 

answer key. You can find the Microsoft Word version on the Assignment page. We would prefer 

the answers are typed and faxed or e-mailed to info@tlch2o.com. If you are unable to do so, 

please write inside the assignment booklet, make a copy for yourself and mail us the completed 

manual. Please feel free to call us if you need assistance. 

Other Student Information 

Feedback Mechanism (Examination procedures) 

Each student will receive a feedback form as part of their study packet. You will be able to find 

this form in the rear of the course or lesson. By completing this form, you can help us improve 

our course and serve your need better in the future. 

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Security and Integrity 

All students are required to do their own work. All lesson sheets and final exams are not 

returned to the student to discourage sharing of answers. Any fraud or deceit will result in the 

student forfeiting all fees, and the appropriate agency will be notified. 

Grading Criteria 

TLC offers the student either pass/fail or a standard letter grading assignment if we are notified 

by the student. If we are not notified, you will only receive a certificate for passing the test. 

Recordkeeping and Reporting Practices 

TLC will keep all student records for a minimum of seven years. It is the student’s responsibility 

to give the completion certificate to the appropriate agencies. TLC will not release any records 

to any party, except to the student self. 

ADA Compliance 

TLC will make reasonable accommodations for persons with documented disabilities. Students 

should notify TLC and their instructors of any special needs. Course content may vary from this 

outline to meet the needs of this particular group. 

Note to Students 

Keep a copy of everything that you submit! If your work is lost, you can submit your copy for 

grading. If you do not receive your certificate of completion or other results within two to three 

weeks after submitting it, please contact your instructor. 

Educational Mission 

The educational mission of TLC is: 

To provide TLC students with comprehensive and ongoing training in the theory and skills 

needed for the pesticide application field, 

To provide TLC students with opportunities to understand and apply the theory and skills 

needed for pesticide application certification, 

To provide opportunities for TLC students to learn and practice pesticide application skills with 

members of the community for the purpose of sharing diverse perspectives and experience, 

To provide a forum in which students can exchange experiences and ideas related to pesticide 

application education, 

To provide a forum for the collection and dissemination of current information related to 

pesticide application education, and 

To maintain an environment that nurtures academic and personal growth. 

Mission Statement 

Our only product is educational service. Our goal is to provide you with the best education 

service possible. TLC attempts to make your learning experience an enjoyable educational 

opportunity. 

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TABLE OF CONTENTS 

Water Treatment Terms 15 

Water Treatment 21 

Preliminary Treatment 23 

Rapid Sand 31 

Backwash Rule 39 

Types of Filters 43 

Jar Testing 47 

Measuring Turbidity 49 

Potassium Permanganate 53 

Dissolved Oxygen 62 

Total Dissolved Solids 63 

Total Organic Carbon 65 

Surface Wash 71 

Pressure Filters 73 

Filtration Process 77 

Backwash Process 79 

Chemical Treatment 83 

Water Treatment Chemicals 87 

Solubility 89 

Coagulation 91 

Hard Water 97 

Membrane Filtration 105 

Reverse Osmosis 109 

GAC PAC 113 

Ultraviolet Radiation 117 

Corrosion Control 121 

Alkalinity 124 

Surface Wash 127 

Water Production 131 

Contaminated Wells 135 

Groundwater 138 

Well Surging 147 

Pumping Equipment 150 

Water Storage 157 

Understanding Water Quality 159 

Types of Algae 155 

Bacteriological Monitoring 167 

Heterotrophic Plate Count 173 

Total Coliforms 176 

Pathogens 177 

Viral Diseases 179 

Cryptosporidiosis 181 

General Contaminants 183 

Chain of Custody 187 

Sampling Plans 191 

pH Scale 195 

Disinfection Terminology 196 

Service Connections 375 

Chemical Monitoring 197 

Troubleshooting Sampling 201 

Microbes 203 

MCLs 213 

New EPA Rules 215 

Primary Water Regulations 219 

Secondary Standards 225 

Chlorine 229 

Chemical Equations 235 

Chemistry of Chlorination 241 

DDBPs 245 

Chlorination Equipment 249 

Troubleshooting Hypochlorination 253 

Alternate Disinfectants 255 

Chlorine Exposure 263 

Fluoride 265 

Pump, Motors and Hydraulics 269 

Hydraulic Terms 271 

Pressure 276 

Atmospheric Pressure 279 

Pump Definitions 283 

Types of Pumps 287 

Pump Categories 289 

Understanding the Pump 291 

Submersible Pump 295 

Vertical Turbine 297 

Centrifugal Pump 303 

Pump Performance 310 

Motors, Couplings and Bearing 315 

Slip Ring 324 

Couplings 325 

Mechanical Seals 329 

Maintenance 331 

Troubleshooting Pumps 333 

Backflow 337 

Cross-Connection Terms 339 

Backpressure 343 

Backflow Responsibility 345 

Methods and Assemblies 347 

Water Distribution Section 353 

Distribution Design 355 

Distribution Valves 357 

Common Rotary Valves 359 

Needle Valves 363 

Butterfly 367 

Actuators and Control Devices 369 

Pressure Reducing Valve 373 

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System Layouts 379 

Types of Pipes 383 

Troubleshooting Distribution 389 

Glossary 391 

Microorganism Appendix 431 

Protozoa 433 

Protozoan Diseases 443 

Giardia Lamblia 445 

Entamoeba Histolytica 448 

Bacteria Section 457 

Salmonella 463 

Escherichia Coli 465 

Math Conversions 485 

References 501 

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Common Water Treatment Acronyms 

AA Activated alumina 

AC Activated carbon 

ASR Annual Status Report 

As(III) Trivalent arsenic, common inorganic form in water is arsenite, H3AsO3 

As(V) Pentavalent arsenic, common inorganic form in water is arsenate, H2AsO4 

BDAT best demonstrated available technology 

BTEX Benzene, toluene, ethylbenzene, and xylene 

CCA Chromated copper arsenate 

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act 

CERCLIS 3 CERCLA Information System 

CLU-IN EPA’s CLeanUp INformation system 

CWS Community Water System 

cy Cubic yard 

DDT Dichloro-diphenyl-trichloroethane 

DI De-ionized 

DOC Dissolved organic carbon 

DoD Department of Defense 

DOE Department of Energy 

EDTA Ethylenediaminetetraacetic acid 

EPA U.S. Environmental Protection Agency 

EPT Extraction Procedure Toxicity Test 

FRTR Federal Remediation Technologies Roundtable 

ft feet 

GJO DOE’s Grand Junction Office 

gpd gallons per day 

gpm gallons per minute 

HTMR High temperature metals recovery 

MCL Maximum Contaminant Level (enforceable drinking water standard) 

MF Microfiltration 

MHO Metallurgie-Hoboken-Overpelt 

mgd million gallons per day 

mg/kg milligrams per kilogram 

mg/L milligrams per Liter 

NF Nanofiltration 

NPL National Priorities List 

OCLC Online Computer Library Center 

ORD EPA Office of Research and 

Development 

OU Operable Unit 

PAH Polycyclic aromatic hydrocarbons 

PCB Polychlorinated biphenyls 

POTW Publicly owned treatment works 

PRB Permeable reactive barrier 

RCRA Resource Conservation and Recovery Act 

Redox Reduction/oxidation 

RO Reverse osmosis 

ROD Record of Decision 

SDWA Safe Drinking Water Act 

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SMZ surfactant modified zeolite 

SNAP Superfund NPL Assessment Program 

S/S Solidification/Stabilization 

SVOC Semi-volatile organic compounds 

TCLP Toxicity Characteristic Leaching 

Procedure 

TNT 2,3,6-trinitrotoluene 

TWA Total Waste Analysis 

UF Ultrafiltration 

VOC Volatile organic compounds 

WET Waste Extraction Test 

ZVI Zero valent iron 

Operator Control Panel 

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Water Treatment Terms 

Community Water System (CWS). A public water system that serves at least 15 service 

connections used by year-round residents of the area served by the system or regularly serves 

at least 25 year-round residents. 

Class V Underground Injection Control (UIC). Rule A rule under development covering 

wells not included in Class I, II, III or IV in which nonhazardous fluids are injected into or above 

underground sources of drinking water. 

Contamination Source Inventory. The process of identifying and inventorying contaminant 

sources within delineated source water protection areas through recording existing data, 

describing sources within the source water protection area, targeting likely sources for further 

investigation, collecting and interpreting new information on existing or potential sources 

through surveys, and verifying accuracy and reliability of the information gathered. 

Cryptosporidium. A protozoan associated with the disease cryptosporidiosis in humans. The 

disease can be transmitted through ingestion of drinking water, person-to-person contact, or 

other exposure routes. Cryptosporidiosis may cause acute diarrhea, abdominal pain, vomiting, 

and fever that last 1-2 weeks in healthy adults, but may be chronic or fatal in immunocompromised 

people. 

Drinking Water State Revolving Fund (DWSRF). Under section 1452 of the SDWA, the EPA 

awards capitalization grants to states to develop drinking water revolving loan funds to help 

finance drinking water system infrastructure improvements, source water protection, to 

enhance operations and management of drinking water systems, and other activities to 

encourage public water system compliance and protection of public health. 

Exposure. Contact between a person and a chemical. Exposures are calculated as the 

amount of chemical available for absorption by a person. 

Giardia lamblia. A protozoan, which can survive in water for 1 to 3 months, associated with 

the disease giardiasis. Ingestion of this protozoan in contaminated drinking water, exposure 

from person-to-person contact, and other exposure routes may cause giardiasis. The 

symptoms of this gastrointestinal disease may persist for weeks or months and include 

diarrhea, fatigue, and cramps. 

Ground Water Disinfection Rule (GWDR). Under section 107 of the SDWA Amendments of 

1996, the statute reads, ". . . the Administrator shall also promulgate national primary drinking 

water regulations requiring disinfection as a treatment technique for all public water systems, 

including surface water systems, and as necessary, ground water systems." 

Maximum Contaminant Level (MCL). In the SDWA, an MCL is defined as "the maximum 

permissible level of a contaminant in water which is delivered to any user of a public 

water system." MCLs are enforceable standards. 

Maximum Contaminant Level Goal (MCLG). The maximum level of a contaminant in 

drinking water at which no known or anticipated adverse effect on the health effect of persons 

would occr, and which allows for an adequate margin of safety. MCLGs are non-enforceable 

public health goals. 

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Nephelolometric Turbidity Units (NTU). A unit of measure used to describe the turbidity of 

water. Turbidity is the cloudiness in water. 

Nitrates. Inorganic compounds that can enter water supplies from fertilizer runoff and sanitary 

wastewater discharges. Nitrates in drinking water are associated with methemoglobanemia, or 

blue baby syndrome, which results from interferences in the blood’s ability to carry oxygen. 

Non-Community Water System (NCWS). A public water system that is not a community 

water system. There are two types of NCWSs: transient and non-transient. 

Organics. Chemical molecules contain carbon and other elements such as hydrogen. Organic 

contaminants of concern to drinking water include chlorohydrocarbons, pesticides, and others. 

Phase I Contaminants. The Phase I Rule became effective on January 9, 1989. This rule, 

also called the Volatile Organic Chemical Rule, or VOC Rule, set water quality standards for 8 

VOCs and required all community and Non-Transient, Non-Community water systems to 

monitor for, and if necessary, treat their supplies for these chemicals. The 8 VOCs regulated 

under this rule are: Benzene, Carbon Tetrachloride, para-dichlorobenzene, trichloroethylene, 

vinyl chloride, 1,1,2-trichlorethane, 1,1-dichloroethylene, and 1,2-dichlorothane. 

Per capita. Per person; generally used in expressions of water use, gallons per capita per day 

(gpcd). 

Point-of-Use Water Treatment. Refers to devices used in the home or office on a specific tap 

to provide additional drinking water treatment. 

Point-of-Entry Water Treatment. Refers to devices used in the home where water pipes 

enter to provide additional treatment of drinking water used throughout the home. 

Primacy State State that has the responsibility for ensuring a law is implemented, and has 

the authority to enforce the law and related regulations. State has adopted rules at least as 

stringent as federal regulations and has been granted primary enforcement responsibility. 

Radionuclides. Elements that undergo a process of natural decay. As radionuclides decay, 

they emit radiation in the form of alpha or beta particles and gamma photons. Radiation can 

cause adverse health effects, such as cancer, so limits are placed on radionuclide 

concentrations in drinking water. 

Risk. The potential for harm to people exposed to chemicals. In order for there to be risk, 

there must be hazard and there must be exposure. 

SDWA - The Safe Drinking Water Act. The Safe Drinking Water Act was first passed in 1974 

and established the basic requirements under which the nation’s public water supplies were 

regulated. The US Environmental Protection Agency (EPA) is responsible for setting the 

national drinking water regulations, while individual states are responsible for ensuring that 

public water systems under their jurisdiction are complying with the regulations. The SDWA 

was amended in 1986 and again in 1996. 

Significant Potential Source of Contamination. A facility or activity that stores, uses, or 

produces chemicals or elements, and that has the potential to release contaminants identified 

in a state program (contaminants with MCLs plus any others a state considers a health threat) 

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within a source water protection area in an amount which could contribute significantly to the 

concentration of the contaminants in the source waters of the public water supply. 

Sole Source Aquifer (SSA) Designation. The surface area above a sole source aquifer and 

its recharge area. 

Source Water Protection Area (SWPA). The area delineated by the state for a PWS or 

including numerous PWSs, whether the source is ground water or surface water or both, as 

part of the state SWAP approved by the EPA under section 1453 of the SDWA. 

Sub-watershed. A topographic boundary that is the perimeter of the catchment area of a 

tributary of a stream. 

State Source Water Petition Program. A state program implemented in accordance with the 

statutory language at section 1454 of the SDWA to establish local voluntary incentive-based 

partnerships for SWP and remediation. 

State Management Plan (SMP) Program. A state management plan under FIFRA required 

by the EPA to allow states (e.g. states, tribes and U.S. territories) the flexibility to design and 

implement approaches to manage the use of certain pesticides to protect ground water. 

Surface Water Treatment Rule (SWTR). The rule specifies maximum contaminant level 

goals for Giardia lamblia, viruses and Legionella, and promulgated filtration and disinfection 

requirements for public water systems using surface water sources, or by ground water 

sources under the direct influence of surface water. The regulations also specify water quality, 

treatment, and watershed protection criteria under which filtration may be avoided. 

Susceptibility Analysis. An analysis to determine, with a clear understanding of where the 

significant potential sources of contamination are located, the susceptibility of the public water 

systems in the source water protection area to contamination from these sources. This 

analysis will assist the state in determining which potential sources of contamination are 

"significant." 

To the Extent Practical. States must inventory sources of contamination to the extent they 

have the technology and resources to complete an inventory for a Source Water Protection 

Area delineated as described in the guidance. All information sources may be used, 

particularly previous Federal and state inventories of sources. 

Transient/Non-Transient, Non-Community Water Systems (T/NT, NCWS). Water systems 

that are non-community systems: transient systems serve 25 non-resident persons per day for 

6 months or less per year. Transient non-community systems typically are restaurants, hotels, 

large stores, etc. Non-transient systems regularly serve at least 25 of the same non-resident 

persons per day for more than 6 months per year. These systems typically are schools, 

offices, churches, factories, etc. 

Treatment Technique. A specific treatment method required by the EPA to be used to control 

the level of a contaminant in drinking water. In specific cases where the EPA has determined it 

is not technically or economically feasible to establish an MCL, the EPA can instead specify a 

treatment technique. A treatment technique is an enforceable procedure or level of technical 

performance which public water systems must follow to ensure control of a contaminant. 

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Total Coliform. Bacteria that are used as indicators of fecal contaminants in drinking water. 

Toxicity. The property of a chemical to harm people who come into contact with it. 

Underground Injection Control (UIC) Program. The program is designed to prevent 

underground injection which endangers drinking water sources. The program applies to 

injection well owners and operators on Federal facilities, Native American lands, and on all 

U.S. land and territories. 

Watershed. A topographic boundary area that is the perimeter of the catchment area of a 

stream. 

Watershed Approach. A watershed approach is a coordinating framework for environmental 

management that focuses public and private sector efforts to address the highest priority 

problems within hydrologically-defined geographic areas, taking into consideration both ground 

and surface water flow. 

Watershed Area. A topographic area that is within a line drawn connecting the highest points 

uphill of a drinking water intake, from which overland flow drains to the intake. 

Wellhead Protection Area (WHPA). The surface and subsurface area surrounding a well or 

well field, supplying a PWS, through which contaminants are reasonably likely to move toward 

and reach such water well or well field. 

More SDWA Information 

Any federal agency having jurisdiction over federally owned and maintained public water 

systems must comply with all federal, state, and local drinking water requirements as well as 

any underground injection control programs (Section 1447). The Act provides for waivers in 

the interest of national security. 

Procedures for judicial review are outlined (Section 1448), and provision for citizens' civil 

actions is made (Section 1449). Citizen suits may be brought against any person or agency 

allegedly in violation of provisions of the Act, or against the Administrator for alleged failure to 

perform any action or duty which is not discretionary. 

EPA may use the new estrogenic substances screening program created in the Food Quality 

Protection Act of 1996 (P .L. 104-170) to provide for testing of substances that may be found 

in drinking water if the Administrator determines that a substantial population may be exposed 

to such substances (Section 1457). 

EPA is directed to conduct drinking water studies involving subpopulations at greater risk and 

biological mechanisms, and studies to support several rules including those addressing 

D/DBPs and Cryptosporidium. The Centers for Disease Control and Prevention and EPA 

must conduct pilot waterborne disease occurrence studies by August 1998. (Section 1458). 

The Act includes a provision amending the Federal Food, Drug, and Cosmetic Act, generally 

requiring the Secretary of Health and Human Services to issue bottled drinking water 

standards for contaminants regulated under the Safe Drinking Water Act. 

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Other provisions of P.L. 104-182 authorize water and wastewater grants for colonias and 

Alaska rural and native villages, and authorize the transfer of the Washington (D.C.) Aqueduct 

to a regional authority. 

The 1996 Amendments also authorize a $50 million per year grant program for additional 

infrastructure and watershed protection projects; the conference report lists, and directs EPA 

to give priority consideration to, 24 such projects. 

IDEXX’s SimPlate for HPC method is used for the quantification of heterotrophic plate 

count (HPC) in water. It is based on the Multiple Enzyme Technology which detects 

viable bacteria in water by testing for the presence of key enzymes known to be 

present in these little organisms. This technique uses enzyme substrates that produce 

a blue fluorescence when metabolized by waterborne bacteria. The sample and 

media are added to a SimPlate Plate, incubated and then examined for fluorescing 

wells. The number of wells corresponds to a Most Probable Number (MPN) of total 

bacteria in the original sample. The MPN values generated by the SimPlate for HPC 

method correlate with the Pour Plate method using the Total Plate Count Agar, 

incubated at 35 o C for 48 hours as described in Standard Methods for the Examination 

of Water and Wastewater, 19 th Edition. 

We will be more into detail in the Water Monitoring Section. 

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Sampling Plan 

A written sampling plan must be developed by the water system. These plans will be reviewed 

by the Health Department or State Drinking Water agency during routine field visits for sanitary 

surveys or technical assistance visits. This plan should include: 

1. The location of routine sampling sites on a system distribution map. You will need to locate 

more routine sampling sites than the number of samples required per month or quarter. A 

minimum of three sites is advised and the sites should be rotated on a regular basis. 

2. Map the location of repeat sampling sites for the routine sampling sites. Remember that 

repeat samples must be collected within five (5) connections upstream and downstream from 

the routine sample sites. 

3. Establish a sampling frequency of the routine sites. 

4. Sampling technique, establish a minimum flushing time and requirements for free chlorine 

residuals at the sites (if you chlorinate continuously). 

The sampling sites should be representative of the distribution network and pressure zones. If 

someone else, e.g., the lab, collects samples for you, you should provide them with a copy of 

your sampling plan and make sure they have access to all sample sites. 

Grabbing a sample from a stream. 

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Water Treatment Section 

For thousands of years, people have treated water intended for drinking to remove particles of 

solid matter, reduce health risks, and improve aesthetic qualities such as appearance, odor, 

color, and taste. As early as 2000 B.C., medical lore of India advised, “Impure water should 

be purified by being boiled over a fire, or being heated in the sun or by dipping a heated 

iron into it, or it may be purified by filtration through sand and coarse gravel and then 

allowed to cool.” 

The treatment needs of a water system are likely to differ depending on whether the system 

uses a groundwater or surface water source. Common surface water contaminants include 

turbidity, microbiological contaminants (Giardia, viruses and bacteria) and low levels of a 

large number of organic chemicals. Groundwater contaminants include naturally occurring 

inorganic chemicals (such as arsenic, fluoride, radium, radon and nitrate) and a number of 

volatile organic chemicals (VOCs) that have recently been detected in localized areas. 

When selecting among the different treatment options, the water supplier must consider a 

number of factors. These include regulatory requirements, characteristics of the raw water, 

configuration of the existing system, cost, operating requirements and future needs of the 

service area. 

Here is a surface water conventional treatment facility next to a river. 

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Top Photograph - Final Rectangle Sedimentation Basin 

Bottom - Clarifier 

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Preliminary Treatment 

Most lakes and reservoirs are not free of logs, tree limbs, sticks, gravel, sand and rocks, 

weeds, leaves, and trash. If not removed, these will cause problems to the treatment plant’s 

pumps and equipment. The best way to protect the plant is screening. 

Bar screens are made of straight steel bars at the intake of the plant. The spacing of the 

horizontal bars will rank the size. Wire mesh screens are woven stainless steel material and 

the opening of the fabric is narrow. Both require manual cleaning. 

Mechanical bar screens vary in size and use some type of raking mechanism that travels 

horizontally down the bars to scrap the debris off. The type of screening used depends on the 

raw water and the size of the intake. 

Mechanical bar screen, above photograph. 

Non-automated bar screen, below. 

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Pre-Sedimentation 

Once the water passes the bar screens, sand and grit are still present. This will damage plant 

equipment and pipes, so it must be removed. This is generally done with either rectangular- or 

round-shaped clarifers. Sedimentation basins are also used after the flocculation process. 

Let’s first look at the components of a rectangular clarifier. Most are designed with scrapers on 

the bottom to move the settled sludge to one or more hoppers at the influent end of the tank. It 

could have a screw conveyor or traveling bridge used to collect the sludge. The most common 

is a chain and flight collector. Most designs will have baffles to prevent short circuiting and 

scum from entering the effluent. 

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Flights and Chains 

The most important thing to consider is the sludge and scum collection mechanism known as 

the “flights and chains”. They move the settled sludge to the hopper in the clarifier for return 

and they also remove the scum from the surface of the clarifier. The flights are usually wood or 

nonmetallic flights mounted on parallel chains. The motor shaft is connected through a gear 

reducer to a shaft which turns the drive chain. The drive chain turns the drive sprockets and 

the head shafts. The shafts can be located overhead or below. 

Some clarifiers may not have scum removal equipment, so the configuration of the shaft may 

vary. As the flights travel across the bottom of the clarifier, wearing shoes are used to protect 

the flights. The shoes are usually metal and travel across a metal track. 

To prevent damage due to overloads, a shear pin is used. The shear pin holds the gear solidly 

on the shaft so that no slippage occurs. Remember, the gear moves the drive chain. If a heavy 

load is put on the sludge collector system then the shear pin should break. This means that 

the gear would simply slide around the shaft and movement of the drive chain would stop. 

Rectangular basin flights and chains. 

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Circular Clarifiers 

In some circular or square tanks, rotating scrapers are used. The diagram below shows a 

typical circular clarifier. The most common type has a center pier or column. The major 

mechanic parts of the clarifier are the drive unit; the sludge collector mechanism, and the 

scum removal system. 

Circular clarifier and collector mechanism. 

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Pre-Treatment 

Once the water passes the bar screens, sand and grit are still present. This will damage plant 

equipment and pipes, so it must be removed. This is generally done with either rectangular or 

round shaped clarifiers. Sedimentation basins are also used after the flocculation process. 

Clarifiers 

Let’s first look at the components of a rectangular clarifier. Most are designed with scrapers on 

the bottom to move the settled sludge to one or more hoppers at the influent end of the tank. It 

could have a screw conveyor or traveling bridge used to collect the sludge. The most common 

is a chain and flight collector. Most designs will have baffles to prevent short-circuiting and 

scum from entering the effluent. 

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Direct Filtration Plant vs. Conventional Plant 

The only difference is that the sedimentation process or step is omitted from the Direct 

Filtration plant. 

Tours of your facility are a wonderful public image tool. I know that many facilities are 

worried about the public and what could possibly happen, but if you can think positive, 

you may find more support and funding for your future projects. 

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Conventional Treatment Overview & Direct Filtration 

Improving the clarity of surface water has always presented a challenge because source 

quality varies. Traditional treatments rely on expensive, construction-intensive processes with 

lengthy times. 

Suspended particles carry an electrical charge which causes them to repel one another. The 

conventional process uses alum (aluminum sulfate) and cationic polymer to neutralize the 

charge. That allows suspended particles to clump together to form more easily filtered 

particles. 

Alum combines with alkalinity in the raw water to form a white precipitate that neutralizes 

suspended particles' electrical charge and forms a base for coagulating those particles. 

Conventional technology uses a 30 to 50 mg/L alum dosage to form a large floc that requires 

extensive retention time to permit settling. Traditional filter systems use graded silica sand 

filter media. Since the sand grains all have about the same density, larger grains lay toward 

the bottom of the filter bed and finer grains lay at the top of the filter bed. As a result, filtration 

occurs only within the first few inches of the finer grains at the top of the bed. 

A depth filter has four layers of filtration media, each of different size and density. Light, coarse 

material lies at the top of the filter bed. The media become progressively finer and denser in 

the lower layers. Larger suspended particles are removed by the upper layers while smaller 

particles are removed in the lower layers. Particles are trapped throughout the bed, not in just 

the top few inches. That allows a depth filter to run substantially longer and use less backwash 

water than a traditional sand filter. 

As suspended particles accumulate in a filter bed, the pressure drop through the filter 

increases. When the pressure difference between filter inlet and outlet increases by 5 - 10 psi 

(34 to 68 kPa) from the beginning of the cycle, the filter should be reconditioned. Operating 

beyond this pressure drop increases the chance of fouling - called "mud-balling" - within the 

filter. 

The reconditioning cycle consists of an up-flow backwash followed by a down-flow rinse. 

Backwash is an up-flow operation, at about 14 gpm per square foot (34m/hr) of filter bed area 

that lasts about 10 minutes. Turbidity washes out of the filter bed as the filter media particles 

scour one another. The down-flow rinse settles the bed before the filter returns to service. Fast 

rinse lasts about 5 to 10 minutes. 

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Chemical pretreatment is often used to enhance filter performance, particularly when turbidity 

includes fine colloidal particles. Suspended particles are usually electrically charged. Feeding 

chemicals such as alum (aluminum sulfate), ferric chloride, or a cationic polymer neutralizes 

the charge, allowing the particles to cling to one another and to the filter media. 

Chemical pretreatment may increase filtered water clarity, measured in NTU, by 90% 

compared with filtration alone. If an operator is present to make adjustments for variations in 

the raw water, filtered water clarity improvements in the range of 93 to 95% are achievable. 

Example of a small water treatment package plant coagulation, flocculation and 

filtration all within a 20 foot area. 

Package Plants 

Representing a slight modification of conventional filtration technology, package plants are 

usually built in a factory, mounted on skids, and transported virtually assembled to the 

operation site. 

These are appropriate for small community systems where full water treatment is desired, but 

without the construction costs and space requirements associated with separately constructed 

sedimentation basins, filter beds, clear wells, etc. 

In addition to the conventional filtration processes, package plants are found as two types: 

tube-type clarifiers and adsorption clarifiers. 

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Rapid Sand Filtration 

Also known as rapid-sand filtration, this is the most prevalent form of water treatment 

technology in use today. This filtration process employs a combination of physical and 

chemical processes in order to achieve maximum effectiveness, as follows: 

Coagulation 

At the Water Treatment Plant, aluminum sulfate, commonly called alum, is added to the water 

in the "flash mix" to cause microscopic impurities in the water to clump together. The alum 

and the water are mixed rapidly by the flash mixer. The resulting larger particles will be 

removed by filtration. 

Coagulation is the process of joining together particles in water to help remove organic matter. 

When solid matter is too small to be removed by a depth filter, the fine particles must be 

coagulated, or "stuck together" to form larger particles which can be filtered. This is achieved 

through the use of coagulant chemicals. 

Coagulant chemicals are required since colloidal particles by themselves have the tendency to 

stay suspended in water and not settle out. This is primarily due to a negative charge on the 

surface of the particles. All matter has a residual surface charge to a certain degree. But since 

colloidal particles are so small, their charge per volume is significant. Therefore, the like 

charges on the particles repel each other, and they stay suspended in water. 

Coagulant chemicals such as "alum" (aluminum Sulfate) work by neutralizing the negative 

charge, which allows the particles to come together. Other coagulants are called "cationic 

polymers", which can be thought of as positively charged strings that attract the particles to 

them, and in the process, form a larger particle. Also, new chemicals have been developed 

which combine the properties of alum-type coagulants and cationic polymers. Which chemical 

is used depends on the application, and will usually be chosen by the engineer designing the 

water treatment system. 

Aluminum Sulfate is the most widely used coagulant in water treatment. Coagulation is 

necessary to meet the current regulations for almost all potable water plants using surface 

water. Aluminum Sulfate is also excellent for removing nutrients such as phosphorous in 

wastewater treatment. Liquid Aluminum Sulfate is a 48.86% solution. 

Large microorganisms, including algae and amoebic cysts, are readily removed by coagulation 

and filtration. Bacterial removals of 99% are also achievable. More than 98% of poliovirus type 

1 was removed by conventional coagulation and filtration. Several recent studies have shown 

that bacterial and viral agents are attached to organic and inorganic particulates. Hence, 

removal of these particulates by conventional coagulation and filtration is a major component 

of effective treatment for the removal of pathogens. 

Flocculation 

The process of bringing together destabilized or coagulated particles to form larger masses 

which can be settled and/or filtered out of the water being treated. In this process, which 

follows the rapid mixing, the chemically treated water is sent into a basin where the suspended 

particles can collide, agglomerate (stick together), and form heavier particles called “floc”. 

Gentle agitation of the water and appropriate detention times (the length of time water remains 

in the basin) help facilitate this process. 

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The water is slowly mixed in contact chambers allowing the coagulated particles, now called 

"floc," to become larger and stronger. As these floc particles mix in the water, bacteria and 

other microorganisms are caught in the floc structure. 

Pre-Sedimentation 

Depending on the quality of the source water, some plants have pre-sedimentation. 

A. To allow larger particles time to settle in a reservoir or lake (sand, heavy silt) reducing solid 

removal loads. 

B. Provides an equalization basin which evens out fluctuations. 

Sedimentation Basin Zones 

A. Inlet Zone 

B. Settling Zone 

C. Sludge Zone 

D. Outlet Zone 

Shapes for a Sedimentation Basin 

A. Rectangular Basins 

B. Circular Basins 

C. Square Basins 

D. Double deck Basins 

Sedimentation 

The process of suspended solid particles settling out (going to the bottom of the vessel) in 

water. 

Following flocculation, a sedimentation step may be used. During sedimentation, the velocity 

of the water is decreased so that the suspended material, including flocculated particles, can 

settle out by gravity. Once settled, the particles combine to form a sludge that is later removed 

from the bottom of the basin. 

Filtration 

A water treatment step used to remove turbidity, dissolved organics, 

odor, taste and color. The water flows by gravity through large filters 

of anthracite coal, silica sand, garnet and gravel. The floc particles 

are removed in these filters. The rate of filtration can be adjusted to 

meet water consumption needs. Filters for suspended particle 

removal can also be made of graded sand, granular synthetic 

material, screens of various materials, and fabrics. 

The most widely used are rapid-sand filters in tanks. In these units, 

gravity holds the material in place and the flow is downward. The 

filter is periodically cleaned by a reversal of flow and the discharge 

of back-flushed water into a drain. 

Cartridge filters made of fabric, paper, or plastic material are also 

common and are often much smaller and cheaper, as well as 

disposable. Filters are available in several ratings, depending on the 

size of particles to be removed. Activated carbon filters, described 

earlier, will also remove turbidity, but would not be recommended for 

that purpose only. 

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With most of the larger particles settled out, the water now goes to the filtration process. At a 

rate of between 2 and 10 gpm per square foot, the water is filtered through an approximate 36" 

depth of graded sand. Anthracite coal or activated carbon may also be included in the sand to 

improve the filtration process, especially for the removal of organic contaminants and taste 

and odor problems. The filtration process removes the following types of particles: 

� Silts and clay 

� Colloids 

� Biological forms 

� Floc 

Four Desirable Characteristics of Filter Media 

� Good hydraulic characteristics (permeable) 

� Does not react with substances in the water (inert and easy to clean) 

� Hard and durable 

� Free of impurities and insoluble in water 

Evaluation of overall filtration process performance should be conducted on a routine basis, at 

least once per day. Poor chemical treatment can often result in either early turbidity 

breakthrough or rapid head loss buildup. The more uniform the media, the slower head loss 

buildup. All water treatment plants that use surface water are governed by the U.S. EPA’s 

Surface Water Treatment Rules or SWTR. 

Declining Rate Filters 

The flow rate will vary with head loss. Each filter operates at the same rate, but can have a 

variable water level. This system requires an effluent control structure (weir) to provide 

adequate media submergence. 

Detention Time 

The actual time required for a small amount of water to pass through a sedimentation basin at 

a given rate of flow, or the calculated time required for a small amount of liquid to pass through 

a tank at a given rate of flow. 

Detention Time = (Basin Volume, Gallons) (24 Hours/day) 

Flow, Gallons/day 

Disinfection 

Chlorine is added to the water at the flash mix for pre-disinfection. The chlorine kills or 

inactivates harmful microorganisms. Chlorine is added again after filtration for postdisinfection. 

Jar Testing (More information later in manual. See the Water Quality Section) 

Jar testing traditionally has been done on a routine basis in most water treatment plants to 

control the coagulant dose. Much more information, however, can be obtained with only a 

small modification in the conventional method of jar testing. It is the quickest and most 

economical way to obtain good reliable data on the many variables which affect the treatment 

process. These include: 

� Determination of most effective coagulant. 

� Determination of optimum coagulation pH for the various coagulants. 

� Evaluation of most effective polymers. 

� Optimum point of application of polymers in the treatment train. 

� Optimum sequence of application of coagulants, polymers, and pH adjustment chemicals. 

� Best flocculation time. 

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pH 

Expression of a basic or acid condition of a liquid. The range is from 0-14, zero being the most 

acid and 14 being the most alkaline. A pH of 7 is considered to be neutral. Most natural water 

has a pH between 6.0 and 8.5. 

Caustic 

NaOH (also called Sodium Hydroxide) is a strong chemical used in the treatment process to 

neutralize acidity, increase alkalinity, or raise the pH value. 

Polymer 

A type of chemical, when combined with other types of coagulants, aids in binding small 

suspended particles to larger particles to help in the settling and filtering processes. 

Post-Chlorine 

Where the water is chlorinated to make sure it holds a residual in the distribution system. 

Pre-Chlorine 

Where the raw water is dosed with a large concentration of 

chlorine. 

Pre-Chlorination 

The addition of chlorine before the filtration process will 

help: 

� Control algae and slime growth 

� Control mud ball formation 

� Improve coagulation 

� Precipate iron 

Raw Turbidity 

The turbidity of the water coming to the treatment plant from the raw water source. 

Settled Solids 

Solids that have been removed from the raw water by the coagulation and settling processes. 

Hydrofluosilicic Acid 

(H2SiF6) a clear, fuming corrosive liquid with a pH ranging from 1 to 1.5. Used in water 

treatment to fluoridate drinking water. 

Corrosion Control 

The pH of the water is adjusted with sodium carbonate, commonly called soda ash. Soda ash 

is fed into the water after filtration. 

Zinc Orthophosphate 

A chemical used to coat the pipes in the distribution system to inhibit corrosion. 

Taste and Odor Control 

Powdered activated carbon (PAC) is occasionally added for taste and odor control. PAC is 

added to the flash mix. 

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Water Quality 

Water testing is conducted throughout the treatment process. Items like turbidity, pH, and 

chlorine residual are monitored and recorded continuously. Some items are tested several 

times per day, some once per quarter and others once per year. 

Sampling 

Collect the water sample at least 6 inches under the surface by plunging the container mouth 

down into the water and turning the mouth towards the current by dragging the container 

slowly horizontal. Care should be taken not to disturb the bottom of the water source or along 

the sides. so as not to stir up any settled solids. This would create erroneous results. 

Chemical feed and rapid mix 

Chemicals are added to the water in order to improve the subsequent treatment processes. 

These may include pH adjusters and coagulants. Coagulants are chemicals, such as alum, 

that neutralize positive or negative charges on small particles, allowing them to stick together 

and form larger particles that are more easily removed by sedimentation (settling) or filtration. 

A variety of devices, such as baffles, static mixers, impellers, and in-line sprays can be used to 

mix the water and distribute the chemicals evenly. 

Short-Circuiting 

Short-Circuiting is a condition that occurs in tanks or basins when some of the water travels 

faster than the rest of the flowing water. This is usually undesirable, since it may result in 

shorter contact, reaction, or settling times in comparison with the presumed detention times. 

Tube Settlers 

This modification of the conventional process contains many metal “tubes” that are placed in 

the sedimentation basin, or clarifier. These tubes are approximately 1 inch deep and 36 inches 

long, split-hexagonal shape, and installed at an angle of 60 degrees or less. 

These tubes provide for a very large surface area upon which particles may settle as the water 

flows upwards. The slope of the tubes facilitates gravity settling of the solids to the bottom of 

the basin, where they can be collected and removed. The large surface settling area also 

means that adequate clarification can be obtained with detention times of 15 minutes or less. 

As with conventional treatment, this sedimentation step is followed by filtration through mixed 

media. 

Adsorption Clarifiers 

The concept of the adsorption clarifier package plant was developed in the early 1980’s. This 

technology uses an up-flow clarifier with low-density plastic bead media, usually held in place 

by a screen. This adsorption media is designed to enhance the sedimentation/clarification 

process by combining flocculation and sedimentation into one step. In this step, turbidity is 

reduced by adsorption of the coagulated and flocculated solids onto the adsorption media and 

onto the solids already adsorbed onto the media. 

Air scouring cleans adsorption clarifiers followed by water flushing. Cleaning of this type of 

clarifier is initiated more often than filter backwashing because the clarifier removes more 

solids. As with the tube-settler type of package plant, the sedimentation/clarification process is 

followed by mixed-media filtration and disinfection to complete the water treatment. 

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Clearwell 

The final step in the conventional filtration process, the clearwell provides temporary storage 

for the treated water. The two main purposes for this storage are to have filtered water 

available for backwashing the filter, and to provide detention time (or contact time) for the 

chlorine (or other disinfectant) to kill any microorganisms that may remain in the water. 

Dried backwash channels on top of a cleaned filter bed. 

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Pretreatment sedimentation basin, bottom photograph, sludge drying bed with new 

grass. Time to turn the sludge over. 

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Cholera, top and bottom photos 

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EPA Filter Backwash Rule 

The U.S. Environmental Protection Agency (EPA) has finalized the Long Term 1 Enhanced 

Surface Water Treatment Rule and Filter Backwash Rule (LT1FBR) to increase protection of 

finished drinking water supplies from contamination by Cryptosporidium and other microbial 

pathogens. 

This rule will apply to public water systems using surface water or ground water under the 

direct influence of surface water. This rule will extend protections against Cryptosporidium 

and other disease-causing microbes to the 11,500 small water systems which serve fewer 

than 10,000 people annually. 

This rule also establishes filter backwash requirements for certain public water systems of all 

sizes. The filter backwash requirements will reduce the potential risks associated with 

recycling contaminants removed during the filtration process. 

Background 

The Safe Drinking Water Act (SDWA) requires the EPA to set enforceable standards to 

protect public health from contaminants which may occur in drinking water. The EPA has 

determined that the presence of microbiological contaminants is a health concern. If finished 

water supplies contain microbiological contaminants, disease outbreaks may result. Disease 

symptoms may include diarrhea, cramps, nausea, possibly jaundice, and headaches and 

fatigue. The EPA has set enforceable drinking water treatment requirements to reduce the 

risk of waterborne disease outbreaks. Treatment technologies such as filtration and 

disinfection can remove or inactivate microbiological contaminants. 

Physical removal is critical to the control of Cryptosporidium because it is highly resistant to 

standard disinfection practice. Cryptosporidiosis may manifest itself as a severe infection that 

can last several weeks and may cause the death of individuals with compromised immune 

systems. In 1993, Cryptosporidium caused over 400,000 people in Milwaukee to experience 

intestinal illness. More than 4,000 were hospitalized, and at least 50 deaths were attributed 

to the cryptosporidiosis outbreak. 

The 1996 Amendments to SDWA require the EPA to promulgate an Interim Enhanced 

Surface Water Treatment Rule (IESWTR) and a Stage 1 Disinfection Byproducts Rule 

(announced in December 1998). The IESWTR set the first drinking water standards to 

control Cryptosporidium in large water systems, by establishing filtration and monitoring 

requirements for systems serving more than 10,000 people each. The LT1FBR proposal 

builds on those standards by extending the requirements to small systems. 

The 1996 Amendments also required the EPA to promulgate a Long Term 1 Enhanced 

Surface Water Treatment Rule (for systems serving less than 10,000 people) back in 

November, 2000 ((1412(b)(2)(C)) and also require the EPA to “promulgate a regulation to 

govern the recycling of filter backwash water within the treatment process of a public 

water system” back in August, 2000 ((1412(b)(14)). The current rule includes provisions 

addressing both of these requirements. 

What will the LT1FBR require? 

The LT1FBR provisions will apply to public water systems using surface water or ground 

water under the direct influence of surface water systems. 

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LT1 Provisions - Apply to systems serving fewer than 10,000 people, and fall into the three 

following categories: 

Turbidity 

� Conventional and direct filtration systems must comply with specific combined filter 

effluent turbidity requirements; 

� Conventional and direct filtration systems must comply with individual filter turbidity 

requirements; 

Disinfection Benchmarking 

� Public water systems will be required to develop a disinfection profile unless they 

perform applicability monitoring which demonstrates their disinfection byproduct 

levels are less than 80% of the maximum contaminant levels; 

� If a system considers making a significant change to their disinfection practice they 

must develop a disinfection benchmark and receive State approval for implementing 

the change. 

Other Requirements 

� Finished water reservoirs for which construction begins after the effective date of the 

rule must be covered; and 

� Unfiltered systems must comply with updated watershed control requirements that 

add Cryptosporidium as a pathogen of concern. 

FBR Provisions - Apply to all systems which recycle regardless of population served: 

� Recycle systems will be required to return spent filter backwash water, thickener 

supernatant, and liquids from the dewatering process prior to the point of primary 

coagulant addition unless the State specifies an alternative location; 

� Direct filtration systems recycling to the treatment process must provide detailed 

recycle treatment information to the State, which may require that modifications to the 

recycle practice be made, and; 

� Conventional systems that practice direct recycle, employ 20 or fewer filters to meet 

production requirements during a selected month, and recycle spent filter backwash 

water, thickener supernatant, and/or liquids 

from the dewatering process within the 

treatment process must perform a one 

month, one-time recycle self-assessment. 

The self-assessment requires hydraulic flow 

monitoring and that certain data be reported 

to the State, which may require that 

modifications to the recycle practice be 

made to protect public health. 

Often under the filtration basins are work tunnels, complex machinery, gauges and 

huge water pumps. 

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The Filtration Process 

Removal of suspended solids by filtration plays an important role in the natural treatment of 

groundwater as it percolates through the soil. It is also a major part of most water treatment. 

Groundwater that has been softened or treated through iron and manganese removal will 

require filtration to remove floc created by coagulation or oxidation processes. Since surface 

water sources are subject to run-off and do not undergo natural filtration, it must be filtered to 

remove particles and impurities. 

The filter used in the filtration process can 

be compared to a sieve or microstrainer that 

traps suspended material between the 

grains of filter media. However, since most 

suspended particles can easily pass through 

the spaces between the grains of the filter 

media, straining is the least important 

process in filtration. 

The photograph on the right illustrates 

debris removed during the backwash 

process. The particles are trapped on 

top of the filter media and trapped within 

the media. 

Filtration primarily depends on a combination of complex 

physical and chemical mechanisms, the most important 

being adsorption. Adsorption is the process of particles 

sticking onto the surface of the individual filter grains or 

onto the previously deposited materials. The forces that 

attract and hold the particles to the grains are the same as 

those that work in coagulation and flocculation. In fact, 

some coagulation and flocculation may occur in the filter 

bed, especially if coagulation and flocculation of the water 

before filtration was not properly controlled. Incomplete 

coagulation can cause serious problems in filter operation. 

The photo on the right shows small glass beads laid on top of a sieve. 

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Filtration Methods: The conventional type of water treatment filtration method includes 

coagulation, flocculation, sedimentation, and filtration. Direct filtration method is similar to 

conventional except that the sedimentation step is omitted. Slow sand filtration process does 

not require pretreatment, has a flow of 0.1 gallons per minute per square foot of filter surface 

area, and is simple to operate and maintain. Diatomaceous earth method uses a thin layer of 

fine siliceous material on a porous plate. This type of filtration medium is only used for water 

with low turbidity. Sedimentation, adsorption, and biological action treatment methods are a 

filtration process that involves a number of interrelated removal mechanisms. 

Demineralization is primarily used to remove total dissolved solids from industrial 

wastewater, municipal water, and seawater. 

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Types of Filters 

Several types of filters are used for water treatment. The earliest ones developed were the 

slow sand filters. They typically have filter rates of around 0.05 gpm/ft 2 of surface area. This 

type of filter requires large filter areas. The top several inches of the sand has to be removed 

regularly, usually by hand due to the mass of growing material (“schmutzdecke") that 

collects in the filter. The sand removed is usually washed and returned to the filter. These 

filters are still in use in some small plants, especially in the western United States, as well as 

in many developing countries. They may also be used as a final step in wastewater 

treatment. Most filters are classified by filtration rate, type of filter media, or type of operation 

into: 

A. Gravity Filters 

1. Rapid Sand Filters 

2. High Rate Filters 

-Dual media 

-Multi-media 

B. Pressure Filters 

-Sand or Multi-media 

Rapid Sand Filters 

Rapid sand filters can accommodate filter rates 40 times those of slow sand filters. The major 

parts of a rapid sand filter are: 

� Filter tank or filter box 

� Filter sand or mixed-media 

� Gravel support bed 

� Underdrain system 

� Wash water troughs 

� Filter bed agitators 

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The filter tank is generally constructed of concrete and is most often rectangular. Filters in 

large plants are usually constructed next to each other in a row, allowing the piping from the 

sedimentation basins to feed the filters from a central pipe gallery. Some smaller plants are 

designed with the filters forming a square of four filters with a central pipe gallery feeding the 

filters from a center well. 

Filter Sand 

The filter sand used in rapid sand filters is manufactured specifically for the purpose of water 

filtration. Most rapid sand filters contain 24-30 inches of sand, but some newer filters are 

deeper. The sand used is generally 0.4 to 0.6 mm in diameter. This is larger than the sand 

used in slow rate filtration. The coarser sand in the rapid filters has larger voids that do not fill 

as easily. The gravel installed under the sand layer(s) in the filter prevents the filter sand 

from being lost during the operation. The under-gravel also distributes the backwash water 

evenly across the total filter. This under-gravel supports the filter sand and is usually graded 

in three to five layers, each generally 6-18 inches in thickness, depending on the type of 

underdrain used. 

Underdrain 

The filter underdrain can be one of many types, such as: 

� Pipe laterals 

� False floor 

� Leopold system 

� Porous plates or strainer nozzles 

� Pipe laterals 

A pipe lateral system uses a control manifold with several perforated laterals on each side. 

Piping materials include cast iron, asbestos cement, and PVC. The perforations are usually 

placed on the underside of the laterals to prevent them from plugging with sand. This also 

allows the backwash to be directed against the floor, which helps keep the gravel and sand 

beds from being directly disturbed by the high velocity water jets. 

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False floor 

The false floor design of a filter underdrain is used together with a porous plate design or 

with screens that retain the sand when there is no undergravel layer. This type of underdrain 

allows the plenum or open space under the floor to act as the collection area for the filtered 

water and for the distribution of the filter backwash water. 

Leopold system 

The Leopold system consists of a series of clay or plastic blocks that form the channels to 

remove the filtered water from the filter and distribute the backwash water. This type of 

underdrain is generally used with an undergravel layer, although some new designs allow for 

sand retention without gravel. 

Washwater Troughs 

Washwater troughs placed above the filter media collect the backwash water and carry it to 

the drain system. Proper placement of these troughs is very important to ensure that the filter 

media is not carried into the troughs during the backwash and removed from the filter. The 

wash troughs must be installed at the same elevation so that they remove the backwash 

evenly from the filter and so that an even head is maintained across the entire filter. These 

backwash troughs are constructed from concrete, plastic, fiberglass, or other corrosionresistant 

materials. 

The photograph above shows exposed filter troughs. 

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Nature of turbidity: The turbidity in natural surface waters is composed of a large number of 

sizes of particles. The sizes of particles can be changing constantly, depending on 

precipitation and manmade factors. When heavy rains occur, runoff into streams, rivers, and 

reservoirs occurs, causing turbidity levels to increase. In most cases, the particle sizes are 

relatively large and settle relatively quickly in both the water treatment plant and the source 

of supply. However, in some instances, fine, colloidal material may be present in the supply, 

which may cause some difficulty in the coagulation process. 

Generally, higher turbidity levels require higher coagulant dosages. However, seldom is the 

relationship between turbidity level and coagulant dosage linear. Usually, the additional 

coagulant required is relatively small when turbidities are much higher than normal due to 

higher collision probabilities of the colloids during high turbidities. Conversely, low turbidity 

waters can be very difficult to coagulate due to the difficulty in inducing collision between the 

colloids. In this instance, floc formation is poor, and much of the turbidity is carried directly to 

the filters. Organic colloids may be present in a water supply due to pollution, and these 

colloids can be difficult to remove in the coagulation process. In this situation, higher 

coagulant dosages are generally required. 

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Jar Test Section 

Jar testing, to determine the proper coagulant dosage, continues to be one of the most 

effective tools available to surface water plant operators. Finished water quality, cost of 

production, length of filter runs, and overall filter life all depend on the proper application of 

chemicals to the raw water entering the treatment plant. 

Instructions 

The jar test, as with any coagulant test, will only provide accurate results when properly 

performed. Because the jar test is intended to simulate conditions in your plant, developing 

the proper procedure is very important. Take time to observe what happens to the raw water 

in your plant after the chemicals have been added, then simulate this during the jar test. THE 

RPM OF THE STIRRER AND THE MINUTES TO COMPLETE THE TEST DEPEND ON 

CONDITIONS IN YOUR PLANT. If, for instance, your plant does not have a static or flash 

mixer, starting the test at high rpm would provide misleading results. This rule applies to 

flocculator speed, length of settling time and floc development. Again, operate the jar test to 

simulate conditions in YOUR plant. 

1. SCOPE 

1.1 This practice covers a 

general procedure for the 

evaluation of a treatment to 

reduce dissolved, suspended, 

colloidal, and non-settleable 

matter from water by chemical 

coagulation-flocculation, followed 

by gravity settling. The procedure 

may be used to evaluate color, 

turbidity, and hardness reduction. 

1.2 The practice provides a 

systematic evaluation of the 

variables normally encountered in 

the coagulation-flocculation 

process. 

1.3 This standard does not 

purport to address the safety concerns, if any, associated with its use. It is the responsibility 

of the user of this standard to establish appropriate safety and health practices and 

determine the applicability of regulatory limitations prior to use. 

Terms Great information for your assignment 

Flocculation - Agglomeration of particles into groups, thereby increasing the effective 

diameter. 

Coagulation - A chemical technique directed toward destabilization of colloidal particles. 

Turbidity - A measure of the presence of suspended solid material. 

Colloidal – A suspension of small particles; a suspension of small particles dispersed in 

another substance. 

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Turbidity 

Particles less than or about 1 to 10 �m in diameter (primarily colloidal particles) will not settle 

out by gravitational forces, therefore making them very difficult to remove. These particles 

are the primary contributors to the turbidity of the raw water causing it to be “cloudy”. The 

most important factor(s) contributing to the stability of colloidal particles is not their mass, but 

their surface properties. 

This idea can be better understood by relating the colloidal particles’ large surface area to 

their small volume (S/V) ratio resulting from their very small size. In order to remove these 

small particles we must either filter the water or somehow incorporate gravitational forces 

such that these particles will settle out. In order to have gravity affect these particles, we 

must somehow make them larger, somehow have them come together (agglomerate); in 

other words, somehow make them “stick” together, thereby increasing their size and mass. 

The two primary forces that control whether or not colloidal particles will agglomerate are: 

Repulsive force 

� q 

An electrostatic force called the “Zeta Potential” - D 

Where: 

ζ = Zeta Potential 

q = charge per unit area of the particle 

d = thickness of the layer surrounding the shear surface 

through which the charge is effective 

D = dielectric constant of the liquid 

Attractive force 

Force due to van der Waals forces 

Van der Waals forces are weak forces based on a polar characteristic induced by 

neighboring molecules. 

When two or more nonpolar molecules, such as 

He, Ar, H2, are in close proximity, the nucleus of 

each atom will weakly attract electrons in the 

counter atom resulting, at least momentarily, in 

an asymmetrical arrangement of the nucleus. 

This force, van der Waals force, is inversely 

proportional to the sixth power of the distance 

(1/d6) between the particles. 

As can clearly be seen from this relationship, 

decay of this force occurs exponentially with 

distance. 

� 

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� 

4 

d

Ways to Measure Turbidity 

1.) Jackson Candle Test 

2.) Secchi Disk - a black and white disk divided like a pie in 4 quadrants about 6" in 

diameter. 

3.) Turbidimeter - Light is passed through a sample. A sensitive photomultiplier tube at a 

90 o angle from the incident light beam detects the light scattered by the particles in the 

sample. The photomultiplier tube converts the light energy into an electrical signal, 

which is amplified and displayed on the instrument. 

a.) Units - Nephelometric Turbidity Unit (NTU) or Formazin Turbidity Unit (FTU). 

How to Treat Turbidity 

Supercharge the water supply - By supercharging the water supply momentarily with a 

positive charge, we can upset the charge effect of the particle enough to reduce the Zeta 

potential (repulsive force), thereby allowing van der Waals forces (attractive forces) to take 

over. 

By introducing aluminum (Al3 + ) into the water in the form of Alum (Al2(SO4)3�nH20) we can 

accomplish the supercharging of the water. This is the coagulation part of the 

coagulation/flocculation process; flocculation follows coagulation. During the flocculation 

process the particles join together to form flocs; the larger the flocs, the faster they will settle 

within a clarifier. 

Other chemical coagulants used are Ferric Chloride and Ferrous Sulfate. Alum works best in 

the pH range of natural waters, 5.0 - 7.5. Ferric Chloride works best at lower pH values, 

down to pH 4.5. Ferrous Sulfate works well through a range of pH values, 4.5 to 9.5. 

During the coagulation process, charged hydroxy-metallic complexes are formed 

momentarily (i.e. Al(OH)2 + , Al(OH)2 1+ etc.). These complexes are charged highly positive, 

and therefore upset the stable negative charge of the target particles, thereby momentarily 

displacing the water layer surrounding the charged particle. This upset decreases the 

distance “d,” in turn decreasing the Zeta potential. 

The particles are then able to get close enough together for van der Waals forces to take 

over and the particles begin to flocculate. The chemical reaction continues until the 

aluminum ions (Al + 3) reach their final form, Al(OH)3 (s), and settle out (note – the flocculated 

particles settle out separately from the precipitated Al(OH)3 (s)). 

If too much alum is added, then the opposite effect occurs--the particles form sub complexes 

with the Al + 3 and gain a positive charge about them, and the particles re-stabilize. 

The final key to obtaining good flocs is the added energy put into the system by way of 

rotating paddles in the flocculator tanks. By “pushing” (adding energy) the particles 

together we can aid in the flocculation process, forming larger flocs. 

It is important to understand that too much energy, i.e. rotating the paddles too fast, would 

cause the particles to shear (breakup), thereby reducing the size of the particles and 

increasing the settling time in the clarifier. 

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Key Equations 

Al ( SO ) � 14. 

3H 

O � 6H 

O � 2Al( 

OH) 

( s) 

� 14. 

3H 

O � 3H 

SO 

(2) 

2 

2 

4 

4 

3 

3 

2 

2 

2 

3 

3 

Al ( SO ) � 14. 

3H 

O � 6Na( 

HCO ) � 2Al( 

OH) 

( s) 

� 3Na 

SO �14. 

3H 

O � 6CO 

(3) 

Al2 4 3 2 

3 

2 4 

2 

( SO ) � 14. 

3H 

O � 6Na( 

OH) 

� 2Al( 

OH) 

( s) 

� 3Na 

SO �14. 

3H 

O 

(4) 

Apparatus 

� Jar Test Apparatus 

� 6 1500 mL Beakers 

� pH meter 

� Pipettes 

� Conductivity Meter 

� Turbidimeter 

Procedure 

� Make up a 10-g/L solution of alum. 

� Make up a 0.1 N solution of NaOH (buffer). (Na +1 = 23 mg/mmol, O -2 = 16 mg/mmol, H + = 

1 mg/mmol) 

� Fill each of the six 1500 mL beakers with one-liter of river water. 

� Measure the temperature and conductivity. 

� Measure the initial pH 

� Add alum and NaOH solutions in equal portions as specified by instructor. 

� Mixing protocol: 

o rapid mix - 1 minute (100 rpm) 

o slow mix - 15 minutes (20 rpm) 

o off, settling - 30 minutes 

� Measure final turbidity. Take the sample from the center, about 2" down for each one 

liter sample. Be careful not to disturb the flocs that have settled. 

� Measure final pH 

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3 

2 

2 

2 

4 

4 

2 

2

Information to be Recorded 

Initial Turbidity = ? NTU Alum - g/L Buffer - 

0.1 N 

Beaker 

Alum (ml) 

Buffer (ml) Turbidity (NTU) pH-Before 

pH-After Temp. o C 

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Preparing Polymers for the Jar Test 

A successful Jar Test is very reliant upon the proper preparation of the polymers being 

tested. Dilution technique ("make down") is especially critical, since it involves compactly 

coiled large molecules in emulsions, prior to activation. The polymer must be uncoiled to 

provide maximum contact with the colloidal particles to be flocculated. If the following 

procedures are not followed, the Jar Test results will be very unreliable. 

Required Equipment: 

� 250 mL bottles with lids. 

� High speed hand mixer (for emulsion polymers). 

� Syringes (1cc, 5cc, 10cc). 

� 250 and 500 mL beakers. 

� Water (it is recommended that the make-down water from the plant be used). 

� Graduated cylinder (100 mL). 

Emulsion Polymers (Prepare 1.0% solution.) 

� Add 198 mL of water to a beaker. 

� Insert Braun mixer into water and begin mixing. 

� Using a syringe, inject 2 mL of neat polymer into vortex. 

� Mix for 20 seconds. Do not exceed 20 seconds! 

� Allow dilute polymer to age for at least 20 minutes, but preferably overnight. Prepare 

0.1% solution. 

� Add 180 mL of water to 250 mL bottle. 

� Add 20 mL of 1.0% polymer solution. 

� Shake vigorously for at least one minute. 

Solution Polymers and Inorganics (Prepare a 1.0% solution.) 

� Add 198 mL of water to 250 mL bottle. 

� Using a syringe, add 2 mL of neat product to bottle. 

� Shake vigorously for at least 1 minute. 

� Prepare 0.1% solution. 

� Add 180 mL to 250 mL bottle. 

� Add 20 mL of 1 % solution. 

� Shake vigorously for at least one minute. 

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Potassium Permanganate Jar Test 

Potassium Permanganate has been used for a number of years in both water and 

wastewater treatment. KMnO4 is a strong oxidizer which can be used to destroy many 

organic compounds of both the natural and man-made origin. KMnO4 is also used to oxidize 

iron, manganese and sulfide compounds and other taste and odor producing substances 

usually due to the presence of very small quantities of secretions given off by microscopic 

algae, which develop on the surface waters and on beds of lakes and rivers under certain 

conditions of temperature and chemical composition. 

KMnO4 must be used with caution, as this material produces an intense purple color when 

mixed with water. As the permanganate ion is reduced during its reaction with compounds 

that it oxidizes, it changes color from purple, to yellow or brown. The final product formed is 

manganese dioxide (MnO2), an insoluble precipitate that can be removed by sedimentation 

and filtration. 

All KMnO4 applied must be converted to manganese dioxide (MnO2) prior to filtration. If it is 

not all converted and is still purple or pink, it will pass through the filter into the clearwell or 

distribution system. This may cause the customer to find pink tap water, or the reaction may 

continue in the system and the same conditions as exist with naturally occurring manganese 

may cause staining of the plumbing fixtures. 

Stock Solutions 

(Strong Stock Solution) 

5 grams potassium permanganate dissolved in 500 ml 

distilled water. 

(Test Stock Solution) 

4 ml strong stock solution thoroughly mixed in 100 ml 

distilled water. 

Each 5 ml of the test stock solution added to a 2000 ml 

sample equals 1 mg/l. 

Jar Testing Example 

If you have a six position stirrer: 

Using a graduated cylinder, measure 2000 ml of the sample to be tested into each of the six 

beakers. Dose each beaker to simulate plant practices in pre-treatment, pH adjustment, 

coagulant,- etc. Do not add carbon or chlorine. Using a graduated pipette, dose each beaker 

with the test stock solution in the following manner. 

Jar # KMnO4 ml KMnO4 mg/l Color 

1 0.50 0.10 no pink 

2 0.75 0.15 no pink 

3 1.00 0.20 no pink 

4 1.25 0.25 no pink 

5 1.50 0.30 pink 

6 1.75 0.35 pink 

Stir the beakers to simulate the turbulence where the KMnO4 is to be added and observe the 

color change. 

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As the iron and manganese begin to oxidize, the sample will turn varying shades of brown, 

indicating the presence of oxidized iron and or manganese. Samples which retain a brown or 

yellow color indicate that the oxidation process is incomplete and will require a higher dosage 

of KMnO4. 

The end point has been reached when a pink color is observed and remains for at least 10 

minutes. In the preceding table a pink color first developed in beaker #5 which had been 

dosed with 1.5 ml/ 0.3 mg/l. If the first jar test does not produce the correct color change, 

continue with increased dosages. 

When applying potassium 

permanganate to raw 

water, care must be taken 

not to bring pink water to 

the filter unless you have 

"greensand". Also, 

permanganate generally 

reacts more quickly at pH 

levels above 7.0. 

Quick Test 

A quick way to check the 

success of a KMnO4 

application is by adding 

1.25 ml of the test stock 

solution to 1000 ml 

finished water. If the 

sample turns brown there 

is iron or manganese 

remaining in the finished 

water. If the sample remains pink, oxidation is complete. 

With proper application, potassium permanganate is an extremely useful chemical treatment. 

As well as being a strong oxidizer for iron and manganese, KMnO4 used as a disinfectant in 

pre-treatment could help control the formation of trihalomethanes by allowing chlorine to be 

added later in the treatment process or after filtration. Its usefulness also extends to algae 

control, as well as many taste/odor problems. 

To calculate the dosage of KMnO4 for iron and manganese removal, here is the formula to 

use. 

KMnO4 Dose, mg/l = 0.6(iron, mg/l) + 2.0(Manganese, mg/l) 

Example: 

Calculate the KMnO4 dose in mg/l for a water with 0.4 of iron. The manganese concentration 

is 1.2 mg/l. 

Known Unknown 

Iron, mg/l = 0.4 mg/l KMnO4 Dose, mg/l 

Manganese, mg/l = 1.2 mg/l 

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Calculate the KMnO4 dose in mg/l. 

KMnO4 Dose, mg/l = 0.6(Iron, mg/l) + 2.0(Manganese, mg/l) 

= 0.6(0.4 mg/l) + 2.0(1.2 mg/l) 

= 2.64 mg/l 

Note: The calculated 2.64 mg/l KMnO4 dose is the minimum dose. This dose assumes there 

are no oxidizable compounds in the raw water. Therefore, the actual dose may be higher. Jar 

testing should be done to determine the required dose. 

Alkalinity 

Introduction 

Alkalinity of water is its acid-neutralizing capacity. It is the sum of all the titratable bases. The 

measured value may vary significantly with the end-point pH used. Alkalinity is a measure of 

an aggregate property of water and can be interpreted in terms of specific substances only 

when the chemical composition of the sample is known. 

Alkalinity is significant in many uses and treatments of natural waters and 

wastewaters. Because the alkalinity of many surface waters is primarily a function of 

carbonate, bicarbonate, and hydroxide content, it is taken as an indication of the 

concentration of these constituents. The measured values also may include contributions 

from borates, phosphates, silicates or other bases if these are present. Alkalinity in excess 

of alkaline earth metal concentrations is significant in determining the suitability of water for 

irrigation. Alkalinity measurements are used in the interpretation and control of water and 

wastewater treatment processes. 

Titration Method 

a. Principle 

Hydroxyl ions present in a sample, as a result of dissociation or hydrolysis of solutes react 

with additions of standard acid. Alkalinity thus depends on the end-point pH used. 

b. Reagents 

i) Standard Hydrochloric Acid – 0.02 N. 

ii) Methyl Orange Indicator – Dissolve 0.1 g of methyl orange in distilled water and dilute to 1 

liter. 

iii) Sodium carbonate solution, 0.02 N : Dry 3 to 5 g primary standard Na2CO3 at 250 o C for 4 

h and cool in a desiccator. Weigh 1.03 gm. 

(to the nearest mg), transfer to a 1-L volumetric flask, fill flask to the mark with distilled water, 

dissolve and mix reagent. Do no keep longer than 1 week. 

c. Procedure 

Titrate over a white surface 100 ml of the sample contained in a 250-ml conical flask with 

standard hydrochloric acid using two or three drops of methyl orange Indicator. 

(NOTE – If more than 30 ml of acid is required for the titration, a smaller suitable aliquot of 

the sample shall be taken.) 

d. Calculation 

Total alkalinity (as CaCO3), mg/l = 10 V or NxVx50x1000 

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T.A. (as CaCO3) = ---------------------- 

Sample Amount 

Where N = Normality of HCl used 

V = volume in ml of standard hydrochloric acid used in the titration. 

Alkalinity to Phenolphthalein 

The sample is titrated against standard acid using phenolphthalein indicator. 

a. Reagents 

i) Phenolphthalein Indicator Solution : 

Dissolve 0.1 g of phenolphthalein in 60 ml of ETHANOL and dilute with Distilled water to 100 

ml. 

ii) Standard hydrochloric Acid – 0.02 N. 

b. Procedure 

Add 2 drops of phenolphthalein indicator solution to a sample of suitable size, 50 or 100 ml, 

in a conical flask and titrate over a while surface with standard hydrochloric acid. 

c. Calculation 

1000 V1 

Alkalinity to phenolphthalein (as CaCO3), mg/l = -------------------- 

Where 

V1 = volume in ml of standard hydrochloric acid used in the titration , and 

V2 = Volume in ml of the sample taken for the test. 

Caustic Alkalinity 

a. General 

Caustic alkalinity is the alkalinity corresponding to the hydroxides present in water and is 

calculated from total alkalinity (T) and alkalinity to phenolphthalein (P). 

b. Procedure 

Determine total alkalinity and 

alkalinity to phenolphthalein and 

calculate caustic alkalinity as shown 

in Table below. 

Result of Titration Caustic Alkalinity 

or Hydroxide Alkalinity as CaCO3 

Carbonate Alkalinity as CaCO3 

Bicarbonate Concentration 

as CaCO3 

Result of Titration 

Caustic 

Alkalinity or 

Hydroxide 

Alkalinity as 

CaCO3 

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V2 

Carbonate 

Alkalinity as 

CaCO3 

P=0 0 0 0 

P1/2T 2P-T 2(T-P) 0 

P=T T 0 0 

Bicarbonate 

Concentration as 

CaCO3

The alkalinity of water is a measure of its capacity to neutralize acids. The alkalinity of 

natural water is due to the salts of carbonate, bicarbonate, borates, silicates and phosphates 

along with the hydroxyl ions in free state. However, the major portion of the alkalinity in 

natural waters is caused by hydroxide, carbonate, and bicarbonates which may be ranked in 

order of their association with high pH values. Alkalinity values provide guidance in applying 

proper doses of chemicals in water and waste water treatment processes, particularly in 

coagulation and softening. 

Alkalinity (total) 

References: ASTM D 1067-92, Acidity or Alkalinity of Water. 

APHA Standard Methods, 19th ed., p. 2-26, method 2320B (1995). 

EPA Methods for Chemical Analysis of Water and Wastes, method 310.1 (1983). 

The alkalinity of water is a measurement of its buffering capacity or ability to react with strong 

acids to a designated pH. Alkalinity of natural waters is typically a combination of 

bicarbonate, carbonate, and hydroxide ions. Sewage and wastewaters usually exhibit higher 

alkalinities either due to the presence of silicates and phosphates or to a concentration of the 

ions from natural waters. 

Alkalinity inhibits corrosion in boiler and cooling waters and is therefore a desired quality 

which must be maintained. It is also measured as a means of controlling water and 

wastewater treatment processes or the quality of various process waters. In natural waters, 

excessive alkalinity can render water unsuitable for irrigation purposes and may indicate the 

presence of industrial effluents. The Titrimetric Method. CHEMetrics' tests determine total or 

"M" alkalinity using an acid titrant and a pH indicator. The end point of the titration occurs at 

pH 4.5. Results are expressed as ppm (mg/L) CaCO3. 

Hardness (calcium) 

Reference: West, T. S., DSC, Ph.D., Complexometry with EDTA and Related Reagents, 3rd 

ed., p. 46, 164 (1969). 

Originally described as water's capacity to precipitate soap, hardness is one of the most 

frequently determined qualities of water. It is a composite of the calcium, magnesium, 

strontium, and barium concentrations in a sample. The current practice is to assume total 

hardness refers to the calcium and magnesium concentrations only. 

Completely de-hardened water, resulting from sodium zeolite or other suitable ion exchange 

treatment, is required for various processes-including power generation, printing and photo 

finishing, pulp and paper manufacturing, and food and beverage processing. Hard water can 

cause scale formation on heat exchange surfaces, resulting in decreased heat transfer and 

equipment damage. 

The Titrimetric Method. This method is specific for calcium hardness. The EGTA titrant in 

alkaline solution is employed with zincon indicator. Results are expressed as ppm (mg/L) 

CaCO3. 

Shelf-life. 8 months. Although the reagent itself is stable, the end point indicator has a limited 

shelf-life. We recommend stocking quantities that will be used within 7 months. 

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Hardness (total) 

References: Colorimetric-Calcichrome chemistry--Method developed by CHEMetrics, Inc. 

Titrimetric--APHA Standard Methods, 19th ed., p. 2-36, method 2340 C (1995). 

EPA Methods for Chemical Analysis of Water and Wastes, method 130.1 (1983). 

For a discussion of hardness, see Hardness (calcium). 

The colorimetric method is applicable to monitoring boiler feedwater and other industrial 

waters. The titrimetric method is applicable to drinking, surface, and brine waters. The 

Colorimetric Method. CHEMetrics developed the sensitive Calcichrome reagent, which is a 

dark purple color. It reacts to form a light purple color at the lower end of the range, and 

forms a light blue color at the end of the range. Results are expressed as ppm (mg/L) or ppb 

(µg/L) CaCO3. The Titrimetric Method. The EDTA titrant is employed in alkaline solution with 

a calmagite indicator. This method determines the combined calcium and magnesium 

concentration of a sample. If no magnesium is present, the end point of the titration normally 

appears sluggish. However, the reagent has been specially formulated to ensure a sharp end 

point, regardless of the presence of magnesium. Results are expressed as ppm (mg/L) 

CaCO3. 

Iron (total) 

Reference: J. A. Tetlow and A. L. Wilson, "Determination of Iron in Boiler Feedwater", 

Analyst, 1958. See discussion under Iron (total & soluble ). CHEMetrics' colorimetric method 

for determining total iron uses thioglycolic acid to dissolve particulate iron and to reduce any 

iron from the ferric to the ferrous state. Ferrous iron then reacts with PDTS in acid solution to 

form a purple-colored chelate. Results are expressed as ppm (mg/L) Fe. 

Manganese 

Reference: APHA Standard Methods, 14th ed., p. 227, method 314C (1975). 

Surface and ground waters rarely contain more than 1 mg/L of soluble or suspended 

manganese. Manganese can act as an oxidizing or reducing agent, depending on its 

valence state. In various forms, it is used as a pigment or a bleaching agent. Manganese 

concentrations in potable water should not exceed 0.05 mg/L. Concentrations greater than 

0.1 mg/L will impart a foul taste to water and discolor laundry and porcelain surfaces. Levels 

higher than 1 mg/l in surface waters can result from mining operations or excessive 

discharging from domestic waste treatment facilities or industrial plants. 

The Colorimetric Method 

CHEMetrics' tests measure soluble manganese compounds but do not differentiate the 

various valence states. Manganese is oxidized in the presence of periodate to form a deepred 

reaction product. Reducing agents will interfere. Results are expressed as ppm (mg/L) 

Mn. 

Fluorides 

Fluoride ions have dual significance in water supplies. High concentration of F- causes 

dental fluorisis (disfigurement of the teeth). At the same time, a concentration less than 0.8 

mg/l results in `dental caries’. Hence it is essential to maintain the F- conc. between 0.8 to 

1.0 mg/L in drinking water. Among the many methods suggested for the determination of 

fluoride ion in water, the colormetric method (SPADNS) & the ion selective electrode method 

are the most satisfactory and applicable to variety of samples. Because all of the 

colorimetric methods are subject to errors due to the presence of interfering ions, it may be 

necessary to distill the sample before making the fluoride estimation, while addition of the 

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prescribed buffer frees the electrode method from the interference, caused by such relatively 

common ions as aluminum hexametaphosphate and orthophosphate which adversely affect 

the colorimetric methods. However, samples containing fluoroborate ion (BF4), must be 

subject to a preliminary distillation step in either of the methods. Both the methods and the 

preliminary distillation step are discussed below. 

1. SPADNS METHOD 

Principle 

Under acid condition fluorides (HF) react with zirconium SPADNS solution and the `Lake’ 

(color of SPADNS reagent) gets bleached due to formation of ZrF6. Since bleaching is a 

function of fluoride ions, it is directly proportional to the concentration of F. It obeys Beer’s 

law in a reverse manner. 

Interference 

Alkalinity 5000 mg/L, aluminum 0.1 mg/L, chlorides 7000 mg/L, Fe 10 mg/L, PO4 16 mg/L, 

SO4 200 mg/L, and hexametaphosphate 1.0 mg/L interfere in the bleaching action. In 

presence of interfering radicals distillation of sample is recommended. 

Apparatus 

1. Distillation apparatus (as shown in the Fig. 3) 

2. Colorimeter for use at 570 nm. 

3. Nessler’s tubes cap. 100 ml. 

Reagents 

1. Sulphuric acid H2SO4 concentration. 

2. Silver Sulfate Ag2SO4 crystals. 

3. SPADNS solution : Dissolve 958 mg SPADNS and dilute to 500 ml. 

4. Ziroconyl acid reagent : Dissolve 133 mg ZrOCl2 8H2O in 25 ml water. Add 350 ml. 

conc. HCl and dilute to 500 ml. 

5. Mix equal volume of 3 and 4 to produce a single reagent. Protect from direct light. 

6. Reference solution: Add 10 ml SPADNS solution to 100 ml distilled water. Dilute 7 ml 

concentration HCl to 10 ml and add to diluted SPADNS solution. 

7. Sodium arsenite solution: Dissolve 5.0 g NaAsO2 and dilute to 1000 ml. 

8. Stock F- solution: Dissolve 221.0 mg anhydrous NaF and dilute to 1000 ml. 1 ml = 100 

mg F-. 

9. Standard F : Dilute stock solution 10 times to obtain 1 ml = 10mg F. 

A. Preliminary Distillation Step 

Place 400 ml distilled water in the distilling flask and carefully add 200 ml 

conc. H2SO4. Swirl until the flask contents are homogenous, add 25 to 30 glass beads and 

connect the apparatus as shown in Fig 1. Begin heating slowly at first and then rapidly until 

the temperature of the flask reaches exactly 180 o C. Discard the distillate. This process 

removes fluoride contamination and adjusts the acid-water ratio for subsequent distillations. 

After cooling, the acid mixture remaining after above step or previous distillation to 120 o C or 

below add 300 ml of sample, mix thoroughly, and distill as before until the temperature 

reaches 180 o C. Do not heat above 180 o C to prevent Sulfate carryover. 

Add Ag2SO4 to distilling flask at the rate of 5 mg/mg Cl when high chloride samples are 

distilled. Use the sulphuric acid solution in the flask repeatedly until the contaminants from 

the samples accumulate to such an extent that recovery is affected or interferences appear 

in the distillate. After the distillation of high fluoride samples, flush the still with 300 ml. 

distilled water and combine the two fluoride distillates. After periods of inactivity, similarly 

flush the still, discard the distillate. 

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B. Procedure 

1. Prepare standard curve in the range 0.0 to 1.40 mg/L by diluting appropriate volume of 

standard F solution to 50 ml in Nessler’s tubes. 

2. Add 10.0 mL mixed reagent prepared as in 5 above to all the samples, mix well and read 

optical density of bleached color at 570 nm using reference solution for setting zero 

absorbance. 

3. Plot conc. Vs. % transmission or absorbance. 

4. If sample contains residual chlorine, remove it by adding 1 drop (0.05ml) NaAsO2 solution 

0.1 mg Cl2 and mix. NaAsO2 conc. should not exceed 1300 mg/L to avoid error due to 

NaAsO2 . Take suitable aliquot & dilute it to 50 mL. 

5. Add acid Zirconyl - SPADNS reagent 10 ml; Mix well and read % transmission or 

absorbance. 

6. Take suitable aliquots of sample either direct or after distillation in Nessler’s tubes. Follow 

the step 5. 

7. Calculate the mg F present in the sample using standard curve. 

2. Ion Selective Electrode Method 

Principle 

The fluoride sensitive electrode is of the solid state type, consisting of a lanthanum fluoride 

crystal; in use it forms a cell in combination with a reference electrode, normally the calomel 

electrode. The crystal contacts the sample solution at one face and an internal reference 

solution at the other. A potential is established by the presence of fluoride ions across the 

crystal, which is measured by a device called ion meter, or by a moder pH meter having an 

expanded millivolt scale. 

The fluoride ion selective electrode can be used to measure the activity or concentration 

of fluoride in an aqueous sample by use of an appropriate calibration curve. However, 

fluoride activity depends on the total ionic strength of the sample. The electrode does not 

respond to bound or complex fluoride. Addition of a buffer solution of high total ionic strength 

containing a chelate to complex aluminum preferentially overcomes these difficulties. 

Interference 

Polyvalent cations such as Al (III), Fe (III) and Si (IV) will complex fluoride ions. However, 

the addition of CDTA (Cyclohexylene diamine tetra acetic acid) preferentially will complex 

concentrations of aluminum up to 5 mg/L. Hydrogen ion forms complex with fluoride, while 

hydroxide ion interferes with electrode response. By adjusting the pH between 5 to 8 no 

interference occurs. 

Apparatus 

1. Ion meter (field / laboratory model) or pH/mV meter for precision laboratory 

measurements. 

2. Reference electrode (calomel electrode) 

3. Fluoride sensitive electrode. 

4. Magnetic stirrer. 

5. Plastic labware (Samples and standards always be stored in plastic containers as fluoride 

reacts with glass). 

Reagents 

1. Standard fluoride solution prepared as directed in SPADNS method. 

2. Total Ionic strength adjustment buffer (TISAB). 

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Place approximately 500 ml distilled water in a 1 - L beaker add 57 mL glacial acetic acid, 58 

gm NaCl and 4.0 gm 1, 2 cyclohexylene diamine tetraacetic acid. Stir to dissolve. Place 

beaker in a cool water bath and add slowly 6 N NaOH (About 125 ml) with stirring, until pH is 

between 5 and 5.5. Transfer to a 1 - L volumetric flask and make up the volume to the mark. 

Procedure 

1. For connecting the electrodes to meter, and for further operation of the instrument, follow 

the instruction manual supplied by the manufacturer. 

2. Check the electrode slope with the ion meter (59.16 mV for monovalent ions and 29.58 

mV for diavalent ions at 25 o C) 

3. Take 50 ml of each 1 ppm and 10 ppm fluoride standard. Add 50 ml TISAB (or 5 ml if 

conc. TISAB is used) and calibrate the instrument. 

4. Transfer 50 to 100 ml of sample to a 150 ml plastic beaker. Add TISAB as mentioned in 

(3). 

5. Rinse electrode, blot dry and place in the sample. Stir thoroughly and note down the 

steady reading on the meter. 

6. Recalibrate every 1 or 2 hours. 

7. Direct measurement is a simple procedure for measuring a large number of 

samples. The temperature of samples and standard should be the same and the ionic 

strength of standard and samples should be made the same by addition of TISAB to all 

solutions. 

8. Direct measurement results can be verified by a known addition procedure. The known 

addition procedure involves adding a standard of known concentration to a sample 

solution. From the change in electrode potential before and after addition, the original 

sample concentration is determined. 

Fluoride SPADNS Method 

References: 

APHA Standard Methods, 20th ed., p. 4-82, method 1500 F-(1998). 

EPA Methods for Chemical Analysis of Water and Wastes, method 340.1 (1974,1978). 

Thomas and Chamberlain, 1974, Colorimetric Analytical Methods, pp 186-193. 

The Fluoride Vacu-vials ® test method is based on the reaction between fluoride and a red 

zirconium-dye lake that has been formed with SPADNS. The loss of color resulting from the 

reaction of the fluoride with the dye lake is a function of the fluoride concentration. Results 

are expressed in ppm (mg/Liter) F-. 

This method is approved by the EPA for NPDES and NPDWR reporting purposes when the 

samples have been distilled from an acid solution. Seawater and wastewater samples must 

be pre-distilled. Distillation removes most contaminating interferences except chlorine. 

Sodium Arsenite has been added to remove up to 5 mg/L chlorine. 

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Oxygen (dissolved) 

References: Indigo Carmine--ASTM D 888-87, Colorimetric Indigo Carmine, Test Method A. 

Gilbert, T.W., Behymer, T.D., Castaneda, H.B., "Determination of Dissolved Oxygen in 

Natural and Wastewaters," American Laboratory, March 1982, pp. 119-134. 

Rhodazine D method--(Method developed by CHEMetrics, Inc.) Power Plant Manual, First 

ed., p. 169 (1984). 

ASTM D 5543-94, Standard Test Methods for Low Level Dissolved Oxygen in Water. 

The level of dissolved oxygen in natural waters is often a direct indication of quality, since 

aquatic plants produce oxygen, while microorganisms generally consume it as they feed on 

pollutants. At low temperatures the solubility of oxygen is increased, so that in winter, 

concentrations as high as 20 ppm may be found in natural waters; during summer, saturation 

levels can be as low as 4 or 5 ppm. Dissolved oxygen is essential for the support of fish and 

other aquatic life and aids in the natural decomposition of organic matter. Waste treatment 

plants which employ aerobic digestion must maintain a level of at least 2 ppm dissolved 

oxygen. This is usually accomplished by mechanical aeration. 

At elevated temperatures, oxygen is highly corrosive to metals, causing "pitting" in ferrous 

systems such as high-pressure boilers and deep well oil recovery equipment. To prevent 

costly corrosion damage, the liquids in contact with the metal surfaces must be treated, 

usually by a combination of physical and chemical means. De-aeration can reduce the 

dissolved oxygen concentration of boiler feedwater from several ppm to a few ppb. Chemical 

reducing agents such as hydrazine or sodium sulfite are sometimes used instead of deaeration, 

but more often are used to react with residual oxygen which remains after the deaeration 

process. 

The Colorimetric Methods. 

Test kits for environmental and drinking water applications (ppm range) employ the indigo 

carmine method. The reduced form of indigo carmine reacts with D.O. to form a blue product. 

The indigo carmine methodology is not subject to interferences from temperature, salinity or 

dissolved gases such as sulfide, which plague users of D.O. meters. Results are expressed 

as ppm (mg/L) O2. 

Test kits for boiler waters and applications requiring trace levels of D.O. (ppb range) employ 

the Rhodazine D methodology. Developed by CHEMetrics, Inc., the Rhodazine D compound 

in reduced form reacts with dissolved oxygen to form a bright pink reaction product. This 

method is not subject to the temperature, salinity, or dissolved gas interferences which 

plague dissolved oxygen meters. Oxidizing agents, including benzoquinone, can cause high 

results. Reducing agents such as hydrazine and sulfite do not interfere. Results are 

expressed as ppm (mg/L) or ppb (µg/L) O2. 

The dissolved oxygen products provide fast, accurate colorimetric oxygen determination. 

Test kit K-7512 is used to monitor surface waters. ULR CHEMets TM ampoules detect oxygen 

to 1 ppb. Test kit K-7540 is widely used to monitor boiler feedwater. 

Boiler feedwater testing: Low range dissolved oxygen test kits include a special "sampling 

tube" (see diagram) for use with boiler feedwater. This device allows the user to break the tip 

of the ampoule in a flowing sample stream in order to preclude error from contamination by 

atmospheric oxygen. 

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Total Dissolved Solids (Filterable) 

The dissolved (Filterable) solids can be determined from the difference between the residue 

on evaporation and total suspended solids, but if the dissolved solids content is low and the 

suspended solids high, a direct determination is better. It is preferable to adopt the 

centrifugal method of separating suspended matter in order that a sufficiently large volume of 

separated liquid is available for the determination. 

Principle 

A known volume of filtered sample is evaporated and dried in a weighed dish at 105 o C to 

constant weight; the increase in weight over the empty dish represents the dissolved solids. 

Apparatus 

1. Evaporating dishes, 50, 100 mL capacity (Preferably porcelain or silica). 

2. Pipettes 25, 50 ml capacity 

3. Water bath & Oven 

4. Balance to weigh up to 4th decimal. 

Procedure 

The known volume (V) of filtered sample in a previously ignited and weighed basin 

(W1). Evaporate to dryness on a steam bath and further dry at 105 o C for one or two hours in 

an oven. Cool in dessicator and weight (W2). Repeat by further heating for 15 minutes and 

cooling until successive results do not differ by more than about 0.4 mg. 

Calculation 

(W2 - W1) x 1000 

Dissolved solids mg/L = ------------------------ 

V 

Where 

W2 = Weight of residue and dish 

W1 = Weight of empty and dry dish 

V = Weight of sample 

Ozone 

Reference: 

DDPD method: Developed by CHEMetrics, Inc. 

Indigo method: Bader, H. and Hoigne, J., "Determination of Ozone in Water by the Indigo 

Method," Water Research, Vol. 15, 449-456, 1981. APHA Standard Methods, 20th ed., p. 4- 

137, Method 4500-03 B (1998). 

Ozone is a strong oxidizing agent. Ozonation is used as an alternative biocide and 

disinfectant to chlorination of drinking water. Ozone is used to remove odor, decolorize, and 

to control algae and other aquatic growths. Because ozone is unstable in water, monitoring 

ozone residuals is important to ensure that proper treatment levels are maintained. 

The Colorimetric Methods 

The DDPD chemistry employs a methyl substituted form of the DPD reagent. The A-7400 

activator solution (potassium iodide) is added to the sample before analysis. Ozone reacts 

with the iodide to liberate iodine. The iodine then reacts with the reagent to give a blue-violet 

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color. Various free halogens and halogenating agents produce color with the reagent. 

Chromate in test samples below 25 ppm will not interfere with results. Results are expressed 

as ppm (mg/L) O3.The new ozone method employs the indigo trisulfonate reagent, which 

reacts instantly and quantitatively with ozone, bleaching the blue color in direct proportion to 

the amount of ozone present. Malonic acid is included in the formulation to prevent 

interference from chlorine. Results are expressed as ppm (mg/L) O3. 

Turbidity 

Suspension of particles in water interfering with passage of light is called turbidity. Turbidity 

is caused by wide variety of suspended matter which range in size from colloidal to coarse 

dispersions, depending upon the degree of turbulence, and also ranges from pure inorganic 

substances to those that are highly organic in nature. Turbid waters are undesirable from an 

aesthetic point of view in drinking water supplies and may also affect products in 

industries. Turbidity is measured to evaluate the performance of water treatment plants. 

Principle 

Turbidity can be measured either by its effect on the transmission of light, which is termed as 

Turbidimetry, or by its effect on the scattering of light, which is termed as Nephelometry. A 

Turbidimeter can be used for samples with moderate turbidity, and a Nephelometer for 

samples with low turbidity. The higher the intensity of scattered light, the higher the turbidity. 

Interference 

Color is the main source of interference in the measurement of turbidity. 

Apparatus : Turbidimeter or Nephelometer. 

Reagents 

1. Solution I : Dissolve 1.0 gm Hydrazine Sulfate and dilute to 100 mL. 

2. Solution II : Dissolve 10.0 gm Hexamethylene tetramine and dilute to 100 mL. 

3. Mix 5 mL of I with 5 mL of II. Allow to stand for 24 hrs. at 25 + 3 o C and dilute to 100 

mL. This solution (III) will have turbidity of 400 units (N.T.U.) 

4. Standard turbidity suspension: Dilute 10 mL of solution III as prepared above to 100 mL to 

have solution of the turbidity of 40 units. (N.T.U.) 

Procedure 

1. Prepare calibration curve in the 

range of 0-400 units by carrying out 

appropriate dilutions of solutions III and 

IV above taking readings on 

turbidimeter. 

2. Take sample or a suitably diluted 

aliquot and determine its turbidity either 

by visual comparison with the diluted 

standards or by reading on 

turbidimeter. 

3. Read turbidity from the standard 

curves and apply correction due to 

dilution, if necessary. 

4. Report the readings in turbidity units. 

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Standard Operating Procedure for the Determination of Total 

Organic Carbon in Water 

1.0 Scope and Application 

This method is used to determine total organic carbon (TOC) in water. A concentration of 

0.01 mg/L can be measured by some instruments if scrupulous attention is given to 

minimizing sample contamination and method background. 

2.0 Summary of Method 

There are two different ways to determine total organic carbon (TOC). The first way is by the 

TOC mode. The inorganic carbon (IC) is first removed from the sample by acidification and 

sparging and then the organic carbon (OC) is oxidized to carbon dioxide (CO2) by sodium 

persulfate in the presence of ultraviolet light. The CO2 produced is purged from the sample, 

dried, and transferred with a carrier gas to a non-dispersive infrared (NDIR) analyzer that is 

specifically tuned to the absorptive wavelength of CO2. The instrument’s microprocessor 

converts the detector signal to organic carbon concentrations in mg/L based on stored 

calibration data. The second way is TOC by difference. This is just total carbon (TC) minus 

inorganic carbon. The TC is all the carbon in the sample, both IC and OC. The IC is 

determined in the same manner as in the TOC mode. 

3.0 Definitions 

3.1 The definitions and purposes below are specific to this method, but have been conformed 

to common usage as much as possible. 

3.2 Liter: L 

Milliliter: mL 

Grams: g 

Total Organic Carbon: TOC 

Total Carbon: TC 

Inorganic Carbon: IC 

Organic Carbon: OC 

Carbon Dioxide: CO2 

Non dispersive infrared: NDIR 

Dissolved organic carbon: DOC 

3.3 May: This action, activity, or procedural step is neither required nor prohibited. May not: 

This action, activity, or procedural step is prohibited. Must: This action, activity, or procedural 

step is required. Shall: This action, activity, or procedural step is required. Should: This 

action, activity, or procedural step is suggested, but not required 

4.0 Interferences 

4.1 Removal of carbonate and bicarbonate by acidification and purging with purified gas 

results in the loss of volatile organic substances. The volatiles also can be lost during sample 

blending, particularly if the temperature is allowed to rise. Another important loss can occur if 

large carbon-containing particles fail to enter the needle used for injection. 

Filtration, although necessary to eliminate particulate organic matter when only dissolved 

organic carbon (DOC) is to be determined, can result in loss or gain of DOC, depending on 

the physical properties of the carbon-containing compounds and adsorption and desorption 

of the carbon matter on the filter. Avoid contaminated glassware, plastic containers, and 

rubber tubing. Insufficient acidification will result in incomplete release of CO2. 

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4.2 The intensity of the ultraviolet light reaching the sample matrix may be reduced by highly 

turbid samples or with aging of the ultraviolet source, resulting in sluggish or incomplete 

oxidation. Large organic particles or very large or complex organic molecules such as 

tannins, lignins, and humic acid may be oxidized slowly because persulfate oxidation is ratelimited. 

However, oxidation of many large biological molecules such as proteins and 

monoclonal antibodies proceeds rapidly. 

4.3 Persulfate oxidation of organic molecules is slowed in samples containing sufficient 

concentrations of chloride by the preferential oxidation of chloride; at concentrations above 

0.05% chloride, oxidation of organic matter may be inhibited. To remove this interference add 

mercuric nitrate to the persulfate solution in UV-persulfate instruments, or extend reaction 

time and/or increase amount of persulfate solution in heated persulfate instruments. 

4.4 With any organic carbon measurement, contamination during sample handling and 

treatment is a likely source of interference. This is especially true of trace analysis. Take 

extreme care in sampling, handling and analysis of samples below 1 mg/L TOC. 

5.0 Safety 

5.1 This method does not address all safety issues associated with its use. The laboratory is 

responsible for maintaining a safe work environment and a current awareness file of OSHA 

regulations regarding the safe handling of the chemicals specified in this method. A 

reference file of material safety data sheets for each chemical used in this method should be 

available to all personnel involved in these analyses. 

5.2 Each chemical should be treated as a potential health hazard. Exposure to these 

chemicals should be reduced to the lowest possible level. It is suggested that the laboratory 

perform personal hygiene monitoring of each analyst using this method and that the results 

of this monitoring be made available to the analyst. 

5.3 Unknown samples may contain high concentrations of volatile compounds. Sample 

containers should be opened in a hood and handled with gloves to prevent exposure. 

6.0 Equipment and Supplies 

Note: Brand names, suppliers, and part numbers are cited for illustrative purposes only. 

No endorsement is implied. Equivalent performance may be achieved using equipment 

and materials other than those specified here, but demonstration of equivalent performance 

that meets the requirements of this method is the responsibility of the laboratory. 

6.1 Tekmar-Dohrman Phoenix 8000 TOC uv-persulfate analyzer or other comparable 

brand with autosampler. 

6.2 0-14 pH paper. 

6.3 10 ml syringe. 

6.4 0.45 micron glass fiber filters. 

6.5 125 ml sample bottles: 

6.6 Autosampler vials: 40 mL amber glass vials with Teflon-faced septa. These vials should 

be washed with laboratory detergent and thoroughly rinsed with tap water followed by 

reverse osmosis water and allowed to dry. The vials should then be rinsed with acetone 

followed by hexane and allowed to dry. Finally, the vials should be dried in the drying oven 

used for drying vials used for the analysis of volatile organic compounds. 

7.0 Reagents and Standards 

7.1 Reagent water: ultrapure from the spectroscopy lab. 

7.2 21% phosphoric acid: add 37 ml of 85% phosphoric acid to 188 ml of reagent 

water. Always add acid to water. 

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7.3 LabChem Inc. Catalog number LC12910-1 Organic carbon stock solution. 1000 parts per 

million. Primary standard grade. 1mL=1mg. If it is prepared in the laboratory, it should be 

preserved by adding phosphoric acid until the pH is

The choice that has been used is 20ppm-200ppm for most samples. If TOC is found by way 

of TC-IC, both curves for TC and IC must be set active. They also must have the same range 

of calibration. The TOC range should not be set active. 

10.3 Once the calibration curve is formed, stop the run and go to the calibration results. 

Choose the standards that have just been run and click on the RECALC button. If you want 

to keep the curve, click on OK and then start the run again. The curve is supposed to be 

linear, so the closer to 1.0000 the better the curve. 

11.0 Procedure 

11.1 Filtration of drinking water-related samples prior to TOC analysis is not permitted as this 

could result in removal of organic carbon. Where turbidity interferes with TOC analysis, 

samples should be homogenized and, if necessary, diluted with organic-free reagent water. 

11.2 Bring the analytical batch of samples to room temperature. Make sure the samples are 

homogenized and pour into labeled amber 40 mL vials. Put on a new septa and place on the 

rack. 

11.3 Check the carbonate and bicarbonate levels of the samples to be analyzed. If they 

are over 800 mg/L then dilute. 

11.4 Make up the reagents weekly. Make up new standards when quality control 

checks start to fail. 

11.5 Warm up the instrument at least one-half hour before use. This means just switch from 

standby to run, and make sure that the gas flow is 200 cc/min. Make sure the baseline has 

stabilized. 

11.6 Create a file and label it according to the current date. An easy way to do this is to load 

an old file from the setup menu and change the samples that are in it to go along with the 

new run. Go to the file and use the “save as” and then type in the day of the run. Put the year 

first then the month and then day. Example: the date of January 21st, 2012 should be read 

as 120121. 

11.7 Set the curve for the desired analysis. The TOC curve should be set for analyzing 

drinking water-related samples. The TC and IC curve needs to be set active for analysis of 

TOC by difference. Make sure that all other curves that are not used are not active. 

11.8 Put the samples on and select run. 

11.9 The calibration curve should be checked after the first standard is run. This will ensure 

the correct calibration is made. The analyst can choose the points on the calibration menu. 

The more linear the line the better, so if the r-squared number is close to one, and the check 

sample is in the tolerance limits, let the rest of the samples run. 

11.10 Only TOC results will be displayed for the drinking water-related samples; whereas the 

TOC by difference will be shown as TC, IC, and TOC on the results portion of the screen. 

12.0 Data Analysis, Calculations, and Reporting Results 

12.1 Calculations 

If the instrument does not already do this, calculate corrected instrument response of 

standards and samples by subtracting the reagent-water blank instrument response vs. TOC 

concentration. Subtract procedural blank from each sample instrument response and 

compare to standard curve to determine carbon content. Apply appropriate dilution factor 

when necessary. Subtract inorganic carbon form total carbon when TOC is determined by 

difference. 

12.2 Reporting Results 

The results can be hand entered or electronically transferred to the Laboratory Information 

Management System (LIMS). The units should be mg/L. 

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13.0 Method Performance 

Interlaboratory studies of persulfate and/or UV with NDIR detection methods have been 

conducted in the range of 0.1 mg/L to 4,000 mg/L of carbon. The resulting equation for 

organic carbon single-operator precision is : 

So= 0.04 x + 0.1 

Overall precision is expressed as: St = 0.08x + 0.1 

where: 

So = single-operator precision 

St = overall precision, and 

x = TOC concentration, mg/L 

14.0 Pollution Prevention 

If mercuric nitrate is used to complex the chloride, use an appropriate disposal method for 

the treated waste to prevent mercury contamination. 

15.0 Waste Management 

15.1 Disposal of any hazardous waste from this method must be done in accordance with 

appropriate regulations. 

15.2 For further information on waste management, consult The Waste Management Manual 

for Laboratory Personnel and Less is Better: Laboratory Chemical Management for Waste 

Reduction, both available from the American Chemical society’s Department of Government 

Relations and Science Policy, 1155 16 th Street N.W., Washington D.C. 20036 

16.0 References 

16.1 Method 5310 C: Total Organic Carbon(TOC), Persulfate-Ultraviolet or Heated- 

Persulfate Oxidation Method, Standard Methods for the Examination of Water 

and Wastewater, 19th edition supplement, 1996, pp.9-14. 

16.2 “Dohrman Phoenix 8000 User Manual”, 7413 East Kemper Road, Cincinnati, 

Ohio 45242-9576. 

16.3 Federal Register, Wednesday, December 16, 1998, p 69417. 

Inside a Turbimeter. 

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Surface Wash 

The photograph above shows a drained filter with the agitator and nozzles exposed. 

During operation these will spin, spraying water during the water backwash. 

During the operation of a filter, the upper six-to-ten inches of the filter media remove most of 

the suspended material from the water. It is important that this layer be thoroughly cleaned 

during the backwash cycle. Normal backwashing does not, in most cases, clean this layer 

completely; therefore, some method of agitation is needed to break up the top layers of the 

filter and to help the backwash water remove any material caught there. 

The surface wash system consists of a series of pipes installed in the filter that introduce 

high velocity water or air jet action into the upper layer of the filter. This jet action will 

generally be supplied by rotating arms that are activated during the backwashing of the filter. 

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A newer design of surface wash uses compressed air to mix the upper layer and loosen the 

particles from the sand so that the backwash water can remove the particles more easily. 

This air wash generally is turned on before the backwash cycle. If both are used at the same 

time, some sand may be washed away. The compressed air rate can be two-to-five cubic 

feet per minute per square foot (cfm/ft 2 ) of filter surface, depending on the design of the filter. 

High Rate Filters 

High rate filters, which operate at a rate three-to-four times that of rapid sand filters, use a 

combination of different filter media, not just sand. The combinations vary with the 

application, but generally they are sand and anthracite coal. Multi-media or mixed-media 

filters use three or four different materials, generally sand, anthracite coal, and garnet. 

In this photograph you can see the water lines on the wall of the filter. The deeper the 

water the more head pressure exerted on the filter media. 

In rapid sand filters, finer sand grains are at the top of the sand layer with larger grains 

farther down into the filter. As a result, the filter removes more suspended material in the first 

few inches of the filter. In the high rate filter, the media size decreases. The top layers 

consist of a coarse material with the finer material farther down, allowing the suspended 

material to penetrate deeper into the filter. 

The material in a filter bed forms layers in the filter, 

depending on their weight and specific gravities. In 

the coarse layer at the top, the larger suspended 

particles are removed first, followed by the finer 

materials. This allows for longer filter runs at higher 

rates than is possible with rapid sand filters. 

The type of filter media used in a high rate filter 

depends on many factors, including the raw-water 

quality, raw-water variations, and the chemical 

treatment used. Pilot studies help the operator 

evaluate which material, or combination of materials, 

will give the best result. 

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Pressure Filters 

Pressure filters fall into two categories: pressure sand and diatomite filters. 

Pressure Sand Filters 

This type of filter is used extensively in iron and 

manganese removal plants. 

A pressure sand filter is contained under pressure in a 

steel tank, which may be vertical or horizontal, 

depending on the space available. As with gravity 

filters, the media is usually sand or a combination of 

media. Filtration rates are similar to gravity filters. 

These filters are commonly used for iron and 

manganese removal from groundwater, which is first 

aerated to oxidize the iron or manganese present, 

then pumped through the filter to remove the 

suspended material. 

Filter Media 

Because the water is under pressure, air binding will not occur in the filter. However, 

pressure filters have a major disadvantage in that the backwash cannot be observed; in 

addition, cracking of the filter bed can occur quite easily, allowing the iron and manganese 

particles to go straight through the filter. When using pressure filters for iron and manganese 

removal, the operator must regularly measure the iron and manganese concentration of the 

filter effluent and backwash the filter before breakthrough occurs. Because of these 

limitations, pressure filters must not be used to treat 

surface water. 

Diatomaceous Earth Filter 

This type of filter is commonly used for the 

treatment of swimming pools. The process was 

developed by the military during World War II to 

remove microorganisms that cause amoebic 

dysentery from water used in the field. 

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Filtration Processes 

Two basic types of filtration processes are currently used in the United States. Conventional 

filtration, the traditional design for many years, provides effective treatment for just about any 

range of raw-water turbidity. Its success is due partially to the sedimentation that precedes 

filtration and follows the coagulation and flocculation steps. Sedimentation, if operated 

properly, should remove most of the suspended material. 

SOURCE WATER 

RESERVOIR 

Surface Water Conventional Treatment: 50 MGD 

BACKWASH & SLUDGE 

DECANT RECYCLE 

CHLORINE 

FERRIC CHLORIDE 

COAGULANT AID 

POLYMER 

CONVENTIONAL TREATMENT: 

MIXING, FLOCCULATION, & 

SEDIMENTATION 

SLUDGE 

STREAM 

CAUSTIC SODA CHLORINE 

FILTRATION 

BACKWASH WATER 

THICKENER 

FINISHED WATER 

RESERVOIR 

LAGOON 

AMMONIA 

DISTRIBUTIO 

N SYSTEM 

After sedimentation, the water passing through to the filters should not have turbidity higher 

than 10-to-15 NTU. Rapid sand filters were once used in the conventional process, but many 

have been converted to multi-media filters in an attempt to increase plant capacity. 

In the other type of filtration process--direct filtration- 

-no sedimentation follows the coagulation phase. 

Direct filtration is designed to filter water with an 

average turbidity of less than 25 NTU. Dual and 

multi-media filters are used with direct filtration. 

They are able to remove more suspended material 

per cubic foot of filter media than sand filters. Direct 

filtration plants have a lower capital cost. However, 

the process cannot handle large variations in raw 

water turbidity. 

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Filtration Operation 

Filtration operation is divided into three steps: filtering, backwashing, and filtering to waste. 

Filter Control of the filter operation requires the following equipment: 

� Rate of flow controller 

� Loss of head indicator 

� On-line turbidimeter 

Rate of Flow Controllers 

Flow rates through filters are controlled by one of two different methods: 

Declining rate 

This method of control is used where the head loss 

through the plant is quite large. It allows the filter head to 

increase until the filter becomes plugged with particles 

and the head loss is too great to continue operation of 

the filter. The rate through the filter is much greater in the 

beginning of a filter run than at the end when the filter is 

dirty. This method tends to be the most commonly 

installed in new filter plants. 

The photograph on right shows operators walking 

through the filter gallery of a plant that uses 

declining rate filters. This is also showing pipelines 

to and from the filter boxes. 

Constant rate 

This type of control monitors the level of water on the top of the filter and attempts to control 

this level from the start of the operation to the end. This is accomplished by the controller 

operating a valve on the effluent of the filter. The valve will be nearly closed at the start of the 

filter run and fully open at the end. This design is used when the head or pressure on the 

filter is limited. 

The photograph above shows the overflow in case the filter level gets too high. 

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Both controllers consist of a venturi tube or some other type of metering device, as well as a 

valve to control the flow from the filter. In most cases, the valve is controlled by an automatic 

control device, often an air-actuated type valve that is controlled by the flow tube controller. 

Loss of head indicator 

As filtration proceeds, an increasing 

amount of pressure, called head 

loss across the filter, is required to 

force the water through the filter. 

The head loss should be 

continuously measured to help 

determine when the filter should be 

backwashed. 

Usually the difference in the head is 

measured by a piezometer 

connected to the filter above the 

media and the effluent line. 

In-line turbidimeter 

Turbidity in water is caused by small 

suspended particles that scatter or 

reflect light so that the water 

appears to be cloudy. Turbidity of 

the filtered water may shelter 

bacteria, preventing chlorine from reaching it during the final disinfection process. The 

turbidity of the filtered water is one of the factors that determine the length of a filter run. At 

some point, the suspended material will start to break through the filter media and increase 

the turbidity of the filter effluent. At this time, the filter should be backwashed. Continuous 

turbidity monitors provide information about when the filter is approaching this point so that 

the operators can start the backwash before the turbidity is too great. Turbidity 

measurements will also indicate whether the coagulation and other treatment processes are 

operating properly. 

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Filtration Process 

Water from the source or, more commonly, from pre-treatment processes, is applied to the 

top of the filter; it then flows downward. The water level above the filter bed is usually kept at 

two-to-six feet. When the filtration is started after being backwashed, there will be little head 

loss. In filters with a control valve installed on the filter effluent pipe, the filter flow is restricted 

during this time. The control valve also has the important function of preventing filter surges, 

which could disturb the media and force floc through the filter. 

The rate of flow on a filter depends on the type of filter. A rapid sand filter will have a flow of 

two-to-three gpm/square foot of filter area. The high rate filter may have four-to-six 

gpm/square foot applied to the surface. A constant rate flow valve is almost fully closed when 

a filter is clean so that the desired water level on top of the filter is maintained. As the filter 

becomes dirty with suspended material, the valve opens gradually until the increase in the 

water level above the filter indicates that the filter needs backwashing. 

The above photograph is a filter from a direct filtration plant; notice the size of the 

floc. 

In filters with variable declining rate flow control, the filters are allowed to take on as much 

water as they can handle. As the filters become dirty, both the headloss and the depth of the 

water on the surface increase until the filters need backwashing. This method is generally 

preferred because it requires less operator attention. With this method, a filter accepts as 

much flow as it can handle. As the filter becomes dirty, the flow through the filter becomes 

less and, if the plant has more than one filter, additional flow redistributes across the other 

filters. A flow restrictor is placed in the filter effluent pipe to prevent a filter inflow that is too 

great for the filter. 

Regardless of the method of control, the filter eventually fills with suspended material. At 

some time, usually after 15 to 30 hours, it will need to be backwashed to clean the media. 

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Back Washing 

Proper backwashing is a very important step in the 

operation of a filter. If the filter is not backwashed 

completely, it will eventually develop additional 

operational problems. If a filter is to operate efficiently, 

it must be cleaned before the next filter run. Treated 

water from storage is used for the backwash cycle. 

This treated water is generally taken from elevated 

storage tanks or pumped in from the clear well. 

During filtration, the filter media becomes coated with 

the floc, which plugs the voids between the filter 

grains, making the filter difficult to clean. The media 

must be expanded to clean the filter during the 

backwash. This expansion causes the filter grains to 

violently rub against each other, dislodging the floc 

from the media. 

The filter backwash rate has to be great enough to 

expand and agitate the filter media and suspend the 

flocs in the water for removal. However, if the filter backwash rate is too high, media will be 

washed from the filter into the troughs and out of the filter. A normal backwash rate is 

between 12 to 15 gpm per square foot of filter surface area. 

In most cases the filter backwash rate will not break up the mass on the top of the filter. The 

design engineer will recommend the installation of a surface wash of some type, the most 

common being a set of rotary arms that are suspended above the media during filtration. 

During filter backwash, the media expands upwards and around the washing arms. A newer 

method of surface wash involves using air scour before the water wash. This is a very 

efficient method, but requires the installation of a large air blower to produce the air. The 

normal design for the air wash will be two-to-five cubic feet of air per square foot of filter 

area. 

Both photographs are part of the backwash equipment for the water plant. 

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The filter should be backwashed when the following conditions have been met: 

� The head loss is so high that the filter no longer produces water at the desired rate; 

and/or 

� Floc starts to break through the filter and the turbidity in the filter effluent increases; 

and/or 

� A filter run reaches a given hour of operation. 

� If a filter is taken out of service for some reason, it must always be backwashed prior 

to be putting on line. 

The decision to backwash the filter 

should not be based on only one of the 

above conditions. If a filter is not 

backwashed until the headloss exceeds 

a certain number of feet, the turbidity 

may break through and cause the filter to 

exceed the standard of 0.5 NTU of 

turbidity. 

Similarly, depending on filter effluent- 

turbidity alone can cause high head loss 

and decreased filter flow rate, which can 

cause the pressure in the filter to drop 

below atmospheric pressure and cause 

the filter to air bind and stop filtering. 

If the water applied to a filter is very good 

quality, the filter runs can be very long. 

Some filters can operate longer than one 

week before needing to be backwashed. 

However, this is not recommended as 

long filter runs can cause the filter media 

to pack down so that it is difficult to 

expand the bed during the backwash. 

Backwashing Process 

The normal method for backwashing a 

filter involves draining the water level 

above the filter to a point six inches 

above the filter media. The surface wash is then turned on and allowed to operate for several 

minutes to break up the crust on the filter. 

After that, the backwash valve is opened, allowing backwash water to start flowing into the 

filter and start carrying suspended material away from the filter. For a filter with an air wash 

instead of a water-surface wash, the filter backwash water and the air wash should not be 

used together. This would be possible only if some means of controlling the media carryover 

is installed. 

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This is a filter control panel. 

The time elapsed from when the filter wash is started until full flow is applied to the filter 

should be greater than one minute. After a few minutes, the filter backwash valve should be 

fully opened to allow full expansion of the filter media. Generally, this expansion will be from 

20 to 40 percent over the normal filter bed volume. The expansion needed will depend on 

how much agitation is needed to suspend the filter media to remove to suspended material 

trapped in the filter. With a multi-media filter, the rate must be high enough to scrub the 

interface between the coal and the sand, where the highest amount of suspended solids will 

be removed from the media. The filter will be washed for 10 to 15 minutes, depending on the 

amount of solids that must be removed. The best way to determine how long the filter should 

be washed is to measure the turbidity of the backwash water leaving the filter. In most cases, 

a filter is washed too long. This could be costly. Too much backwash water is used, and it 

must be treated after use. Backwash valves must be opened slowly. Opening the valves too 

rapidly can cause serious damage to the filter underdrain, filter gravel, and filter media. 

Disposal of Filter Backwash Water 

Water from the filter backwash cannot be returned directly 

to the environment. Normally the water is discharged into 

a backwash tank and allowed to settle. The supernatant, 

or cleared liquid, is then pumped back to the head of the 

treatment plant at a rate not exceeding ten percent of the 

raw water flow entering the plant. The settled material is 

pumped to a sewer or is treated in the solids-handling 

process of the plant. This conserves most of the 

backwash water and eliminates the need to obtain a 

pollution discharge permit for the disposal of the filter 

backwash water. 

Since backwash is a very high flow operation, the surges that are created from the backwash 

coming from the filter must not be allowed to enter the head of the plant. Therefore, the spent 

backwash water must be stored in storage tanks and returned slowly to the treatment 

process. 

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Filter to Waste 

When filtration is started after backwash, filtered water should be wasted until the turbidity in 

the effluent meets standards. Depending on the type of filter, this may last from two to 20 

minutes. This wasting is needed as some suspended material remains in the filter media 

following the backwash. The media needs to become somewhat sticky again to start to 

capture the suspended material. 

Also, the filtration rate is higher in a clean filter, causing more material to be swept from the 

filter during the start-up. Filtration should always be started slowly after a backwash to 

prevent breakthrough of suspended material. 

Filter Aids 

Sometimes, when water passes through a 

filter, the floc is torn apart into smaller particles 

that will penetrate deeply into the filter media, 

causing premature turbidity breakthrough. This 

will require more frequent filter backwashing of 

the filter and use of large volumes of backwash 

water to be able to remove the floc that has 

penetrated deeply into the filter bed. A filter aid 

is a material that adds strength to the floc and 

prevents its breakup. Generally, a polymer is 

used as a filter aid because it creates strong 

bonds with the floc. Polymers are watersoluble, 

organic compounds that can be 

purchased in either wet or dry form. 

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The photograph on the right is showing dry Polymer and on the left side is liquid. 

Polymers have very high molecular weight and cause the floc to coagulate and flocculate 

quickly. Polymers can have positive or negative charges, depending on the type needed to 

cause attraction to the specific floc filtered. 

When used as a filter aid, the polymer strengthens the bonds and prevents the shearing 

forces in the filter from breaking the floc apart. For best results, the polymer should be added 

just ahead of the filter. A normal dose of polymer for filter aiding will be less than 0.1 ppm, 

but the exact dose will be decided by the result of a jar test and by experimentation in the 

treatment plant. Too much polymer will cause the bonds to become too strong, which may 

then cause the filter to plug, especially the top few inches of the filter media. 

Filter Operating Problems 

There are three major types of filter problems. They can be caused by chemical treatment 

before the filter, control of filter flow rate, and backwashing of filters. 

The above photograph shows clumps formed by Powder Activated Carbon. 

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Chemical Treatment before the Filter 

The coagulation and flocculation stages of the water treatment must be monitored 

continuously. Adjustments in the 

amount of coagulant added must be 

made frequently to prevent the filter 

from becoming overloaded with 

suspended material. This overload 

may cause the filter to prematurely 

reach its maximum headloss. 

If there is early turbidity breakthrough 

in the filter effluent, more coagulant 

may have to be added to the 

coagulation process. There may be a 

need for better mixing during the 

coagulation or the addition of more 

filter aid. 

If there is a rapid increase in filter 

head loss, too much coagulant may be 

clogging the filter. Less coagulant or 

less filter aid should be used. The 

operator needs to learn to recognize 

these problems and choose the proper 

corrections. 

Filter aid being fed at the weirs of sedimentation. 

In the photograph above, overfeeding flocculants to meet federal regulations caused 

Iron to precipitate on the filter walls. 

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Control of Filter Flow Rate 

When a filter is subjected to rapid changes in flow rate, the turbidity of the effluent may be 

affected; the dirtier the filter media, the greater the effect. 

When a plant flow changes, the filter flow also has to change to produce the water needed. If 

an increase is necessary, the flow should, if possible, be increased gradually over a tenminute 

period to reduce the impact on the filter. Addition of filter aids may also reduce the 

impact on the filter effluent. 

When backwashing a filter and therefore temporarily taking it out of service, the remaining 

filter(s) must pick up the additional flow. This can cause an abrupt change in flow that will 

cause turbidity breakthrough. This problem can be avoided by keeping one filter in reserve to 

accept this additional flow. If the plant has a backwash storage basin, this will also prevent 

surges to the filters. 

Many plants are not operated continuously, and the start-up at the beginning of the day will 

cause a surge to the filter(s). The filters should be backwashed before putting them back into 

operation or operated to waste until the effluent meets the standards. 

Backwashing of Filters 

Backwashing of the filters is the single most important operation in the maintenance of the 

filters. If the filter is not backwashed effectively, problems may occur that may be impossible 

to correct without totally replacing the filter media. These problems could be caused by 

improper backwashing procedures: 

� Mud balls are formed by the filter media cementing together with the floc that the filter 

is supposed to remove. If the filter is backwashed effectively, the mud balls are 

broken apart and removed. As the balls gain weight, they will settle to the bottom of 

the filter and occupy valuable filter volume. This will cause the flow to increase in the 

areas of the filter that have not been plugged. Additional problems, such as filter 

cracking and separation of the media from the filter walls may also be the result of 

mud-ball formation. 

� Filter bed shrinkage or compaction can result from ineffective backwashing. Media 

grains in a clean filter rest directly against each other with very little compaction. 

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� Filter media in a dirty filter are surrounded by a soft layer which causes it to compact. 

This causes filter bed cracking and separation of the filter media from the walls of the 

filter. When the filter is cracked, it is obvious that the filter will short circuit. The flow 

will seek the crack and go straight through, resulting in excessive turbidity in the 

effluent. 

A photograph of a backwash basin that has media caked on the bottom. 

� Separation of the gravel is caused by the backwash valve opening too quickly; as a 

result, the supporting gravel is forced to the top of the filter. This could also be caused 

by the filter underdrain being plugged, causing uneven distribution of the backwash 

water. When this happens, a boil occurs from the increased velocity in the filter. The 

filter media will start washing into the filter underdrain system and be removed from 

the filter. If displacement has occurred, the filter media must be removed from the 

filter and the filter rebuilt by the placement of each grade of media in its proper place. 

� Air binding of the filter is not common as 

long as the filter is washed regularly. Air 

binding is the result of pressure in the filter 

becoming negative during operation. This 

causes the air dissolved in the water to 

come out of the solution and become 

trapped in the filter, resulting in resistance 

and short filter runs. This negative head 

generally occurs in a filter that has less 

than five feet of head above the 

unexpanded filter bed. If a filter head of 

five feet is not possible, filter backwash 

should be started at a lower head loss 

than normal. 

The photograph on the right shows a filter 

support bed under construction. 

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Air binding can also be caused by the water being cold and super-saturated with air. This air 

bubbles out as the water warms up. It is not possible for the operator to control this situation. 

If it happens, the filter must be backwashed more frequently to correct the filter air binding. 

� Media loss is normal in any filter. Some are lost each time the filter is backwashed, 

especially if the filter surface wash is used. If a large amount of media is being lost, 

the method of washing should be inspected and corrected. The bed should not have 

to be expanded more than 20 percent during the backwash cycle. It may help to turn 

off the surface wash approximately two minutes before the end of the backwash. If 

this does not correct the problem, the filter troughs may have to be raised to prevent 

the excessive media loss. 

Filter On-Line 

After a well-operated filter backwash, the filter should be level and smooth with no cracks or 

mud balls at the surface. A good bed will appear to move laterally during the backwash and 

there will be no boils at the surface. The filter should clear up evenly cleaning. If some areas 

are not clean, there could be an under-drain problem. 

Mudballs can be seen on the top layer of the media bed or during the backwash 

water cycle. Typically, these will not flow over into the filter troughs. 

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More on Water Treatment Chemicals 

Similar chemicals are used for process control, odor control and sludge conditioning in Water 

and Wastewater Treatment. Students will learn about the types of chemicals used and how 

they react in the process. Students will also learn about chemical safety and perform on-site 

equipment assessment. 

The table below is a list of general chemicals used in Water and Wastewater. They may vary 

by the manufacture; a perfect example would be Thioguard®, which is Magnesium 

Hydroxide. In this class we will discuss the chemical name and compound and leave out 

manufacture trade names. 

Common Water/Wastewater Treatment Chemicals 

Chemical Name Common Name Chemical Formula pH (Raise 

or Lowers) 

Aluminum hydroxide Al(OH)3 

Aluminum sulfate Alum, liquid AL2(SO4)3 . 14(H2O) 

Ammonia NH3 

Ammonium NH4 

Bentonitic clay Bentonite 

Calcium bicarbonate Ca(HCO3)2 

Calcium carbonate Limestone CaCO3 

Calcium chloride CaCl2 

Calcium Hypochlorite HTH Ca(OCl)2 . 4H2O 

Calcium hydroxide Slaked Lime Ca(OH)2 

Calcium oxide Unslaked (Quicklime) CaO 

Calcium sulfate Gypsum CaSO4 

Carbon Activated Carbon C 

Carbon dioxide CO2 

Carbonic acid H2CO3 

Chlorine gas Cl2 

Chlorine Dioxide ClO2 

Copper sulfate Blue vitriol CuSO4 . 5H2O 

Dichloramine NHCl2 

Ferric chloride Iron chloride FeCl3 

Ferric hydroxide Fe(OH)3 

Ferric sulfate Iron sulfate Fe2(SO4)3 

Ferrous bicarbonate Fe(HCO3)2 

Ferrous hydroxide Fe(OH)3 

Ferrous sulfate Copperas FeSO4.7H20 

Hydrofluorsilicic acid H2SiF6 

Hydrochloric acid Muriatic acid HCl 

Hydrogen sulfide H2S 

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Chemical Name Common Name Chemical Formula pH (Raise or Lowers) 

Hypochlorus acid HOCL 

Magnesium bicarbonate Mg(HCO3)2 

Magnesium carbonate MgCO3 

Magnesium chloride MgCl2 

Magnesium hydroxide Mg(OH)2 

Magnesium dioxide MgO2 

Manganous bicarbonate Mn(HCO3)2 

Manganous sulfate MnSO4 

Monochloramine NH2Cl 

Potassium bicarbonate KHCO3 

Potassium permanganate KMnO4 

Sodium carbonate Soda ash Na2CO3 

Sodium chloride Salt NaCl 

Sodium chlorite NaClO2 

Sodium fluoride NaF 

Sodium fluorsilicate Na2SiF6 

Sodium hydroxide Lye NaOH 

Sodium hypochlorite NaOCl 

Sodium Metaphosphate Hexametaphosphate NaPO3 

Sodium phosphate Disodium phosphate Na3PO4 

Sodium sulfate Na2SO4 

Sulfuric acid H2SO4 

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Solubility of Substances in Water 

Water is an excellent solvent for many compounds. Some dissolve in it as molecules while 

others, called electrolytes, dissociate and dissolve not as neutral molecules but as charged 

species called ions. Compounds which exist as solid ionic crystals dissolve in water as ions, 

and most of them are highly soluble in water. “Highly soluble” is a somewhat elastic 

description, but generally means soluble to at least the extent of forming 0.1 to 1.0 molar 

aqueous solutions. Salts which are less soluble in water than this at room temperature are 

called slightly soluble salts. 

The solubility of an ionic salt depends both upon its cations and its anions, but for simple 

salts in aqueous solution at room temperature the following general observations are useful. 

Almost all sodium, potassium, and ammonium salts are highly soluble; the only significant 

exception is KCIO4, which is moderately soluble almost without exception. Metal carbonates 

and phosphates are generally insoluble or slightly soluble, with the exception of those of 

sodium, potassium, and ammonium which are highly soluble; magnesium ammonium 

phosphate is used for the precipitation of magnesium ion. 

Metal halides are generally highly soluble, with the exception of those of silver, lead, and 

mercury (I). Lead chloride is slightly soluble while silver and mercury (I) chlorides are much 

less soluble. Sulfate salts are generally highly soluble as well, with more exceptions; calcium, 

barium, strontium, lead, and mercury (I) sulfates are almost insoluble while silver sulfate is 

slightly soluble. Metal sulfides are generally insoluble in water. 

Solid-Solution (Solubility) Reactions 

When solids dissolve, the solutes are no longer pure substances and their activity can no 

longer be taken as unity. In dilute solutions, aqueous or otherwise, activities of solutes are 

often taken as equal to their molar concentrations. These equilibria are called solubility 

equilibria and are taken up under the following main heading. The example below shows how 

the form in which they are written compares to other equilibrium constants. 

Example. The equilibrium constant for the reaction AgCl(s) Ag+(aq)+Cl-(aq) is written as 

K= a(Ag+)a(Cl-)/a(AgCl); more commonly, it is written in the form Ka(AgCl)=a(Ag+)a(Cl- 

)=Ksp. If the molar concentrations are taken as good approximations to the activities, which in 

dilute solutions they are, then Ksp=[Ag+][Cl]. 

Example. Let us write and simplify to the extent possible the equilibrium constant for the 

equilibrium Al 3+ (aq) + 3OH - (aq) A1(OH)3(s) For this equilibrium K= 1/[Al 3+ ][OH - ] 3 = 1/Ksp. 

where K has the units dm 12 /mol 4 , or (dm 3 ) 4 /mol 4 . 

The form of equilibrium constant indicated as Ksp is called the solubility product constant or, 

more commonly, the solubility product. This constant therefore must refer to the process of a 

solid going into solution (solubility) rather than the reverse, precipitation of solid from 

solution. As a consequence, the ions are products and appear in the numerator. 

The value of the solubility product is temperature-dependent and is generally found to 

increase with increasing temperature. As a consequence, the molar solubility of ionic salts 

generally increases with increasing temperature. The extent of this increase varies from one 

salt to another. 

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It is sometimes possible to take advantage of the difference in the effect of temperature to 

separate mixtures of different soluble salts. As the chart in the following Figure shows, a 

solution originally of equal concentration in KClO3 and KNO3 should upon heating and 

evaporation of water precipitate KClO3 because KNO3 is by far the more soluble near the 

boiling point of water. 

The solubility of solid salts in water, and in most other solvents, increases with temperature 

while that of gases decreases. The heat or enthalpy change of the dissolution reaction for 

most solids is positive so the dissolution reaction is endothermic. For some solids, such as 

NaCl, the heat of solution is very small and so the effect of temperature is small also. For 

other salts, such as KNO3, the effect of temperature is much larger: 

NaCl(c) Na + (aq) + Cl - (aq); H0 = (-240.12-167.159) – (-411.153) = +3.87 kJ/mol 

KNO3(c) K + (aq) + NO3 - (aq); H0 = (-252.38-205.0)-(-494.63) = +37.3kJ/mol 

Chemical coagulation in the water/wastewater treatment is the process of bringing 

suspended matter in untreated water together for the purpose of settling and for the 

preparation of the water for filtration. 

Coagulation involves three specific steps, which are: 

� Coagulation 

� Flocculation 

� Sedimentation 

Primary Clarifier 

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Purpose of Coagulation 

Untreated surface waters contain clay, minerals, bacteria, inert solids, microbiological 

organisms, oxidized metals, organic color producing particles, and other suspended 

materials. Some of the microbiological organisms can include Giardia cysts, pathogenic 

bacteria, and viruses. Oxidized metals include iron and manganese. All of these materials 

can inhibit disinfection, cause problems in the distribution system, and leave the water cloudy 

rather than clear. The purpose of coagulation is to remove these particles. 

The ability of particles to remain suspended in water is a function of both the particle size and 

specific gravity. Turbidity particles can range in size from molecular to 50 microns. Particles 

which are greater than one micron in diameter are considered silt, and settle out due to their 

relatively large size and density without the need to coagulate in a matter of seconds or 

minutes. 

Colloidal material ranges in size from 0.001 to one micron 

in diameter. These materials require days to months for 

complete settling. Since detention times in the water 

treatment process are generally less than twelve hours, 

the rate of settling of these colloidal particles must be 

increased in the water treatment process. This is 

accomplished in the coagulation process when tiny 

particles agglomerate into larger, denser particles which 

will settle more quickly as shown in the picture on the 

right. 

These tiny colloidal particles have a very large surface area to mass ratio, and this factor is 

important in keeping the particles suspended for long periods of time. In fact, the surface 

area to mass ratio is so high that electric charges and ionic groups become important in 

keeping the particles suspended. Two types of colloids exist. These are hydrophobic or water 

hating colloids, and hydrophilic or water loving colloids. Hydrophilic colloids form 

suspensions easily, and can be difficult to remove. These colloids can, however, react 

chemically with the coagulants commonly added to water under proper conditions. Examples 

of hydrophilic colloids would be organic color forming compounds. Hydrophobic colloids do 

not easily form suspensions. The reactions between hydrophobic colloids and the coagulants 

commonly added to water are largely physical rather than chemical. Examples of 

hydrophobic colloids would be clays and metal oxides. 

The Coagulation Process 

Coagulation is accomplished by the addition of ions having the opposite charge to that of the 

colloidal particles. Since the colloidal particles are almost always negatively charged, the 

ions which are added should be cations or positively charged. The coagulating power of an 

ion is dependent on its valency or magnitude of charge. A bivalent ion (+2 charge) is 30 to 60 

times more effective than a monovalent ion (+l charge). A trivalent ion (+3 charge) is 700 to 

1000 times more effective than a monovalent ion. 

Typically, two major types of coagulants are added to water. These are aluminum salts and 

iron salts. The most common aluminum salt is aluminum sulfate, or alum. 

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When aluminum sulfate is added to water, the aluminum ions enter into a series of 

complicated reactions. The aluminum ions become hydrated, meaning that water molecules 

attach themselves to the aluminum ions. In addition, anions present in the water, such as 

hydroxide and sulfate ions can attach to the aluminum ions. 

These reactions result in large, positively charged molecules having aluminum ions at their 

center. These particles may have charges as high as +4. Following these reactions, a 

second type of reaction occurs, called Olation. This reaction involves the bridging of two or 

more of these large molecules to form even larger, positively charged ions. A typical 

molecule can contain eight aluminum ions, twenty hydroxide ions, and will have a +4 charge. 

Iron salts behave in a similar manner when added to water. 

Once these large polymeric aluminum or iron compounds are formed, the magnitude of their 

high positive charge allows these species to rapidly move toward the colloid, where they are 

adsorbed onto the negatively charged surface of the turbidity particle. The coagulant 

compounds can penetrate the bound water layer because of their high positive charge. 

This rapid adsorption results in the compression of the electrical double layer, and results in 

the colloid becoming coated with the coagulant compounds. The net result of this process is 

that the electrical charges on the particle are reduced. The suspension is now considered to 

be destabilized, and the particles can be brought together through, among other forces, 

Brownian Movement, and will be held together by the Van der Waals forces. 

An additional process occurs which assists this process. As the coagulant continues to 

undergo the hydrolyzation and olation reactions, progressively larger masses of flocculent 

material are formed. These compounds can become large enough to settle on their own, and 

tend to trap turbidity particles as they settle. This is commonly referred to as sweep floc. 

As the coagulation reactions and destabilization are occurring, the Zeta Potential at the 

surface of the colloid is also found to be reducing. Typically, the Zeta Potential for a naturally 

occurring water may be in the range of -10 to -25 millivolts. As the reactions occur, this Zeta 

Potential will be reduced to approximately -5 millivolts. These figures are only examples of 

what might be considered typical waters. Since all waters exhibit a specific set of 

characteristics, these numbers will vary. It is interesting to note that the Zeta Potential does 

not have to be reduced to zero in order for coagulation to occur, because the forces of 

attraction can become predominant before complete destabilization occurs. 

Hydrophilic colloids participate in the coagulation process in a slightly different way. These 

colloids tend to attract water molecules and attach these water molecules to their surfaces. 

This is also a hydration process, and the water molecules act as a barrier to contact between 

particles. Also attached to the surfaces are hydroxyl, carboxyl, and phosphate groups, all to 

which are negatively charged. Coagulant products react chemically with the negatively 

charged groups attached to the hydrophilic colloids, forming an insoluble product which is 

electrically neutral and destabilized. 

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Factors Influencing Coagulation 

Effects of pH: The pH range in which a coagulation process occurs may be the single most 

important factor in proper coagulation. The vast majority of coagulation problems are related 

to improper pH levels. Whenever possible, coagulation should be conducted in the optimum 

pH zone. When this is not done, lower coagulation efficiency results, generally resulting in a 

waste of chemicals and a lowered water quality. Each of the inorganic salt coagulants has its 

own characteristic optimum pH range. In many plants, it is necessary to adjust the pH level in 

the coagulation process. In most cases this involves the addition of lime, caustic soda, or 

soda ash to maintain a minimum pH level. In some cases, however, acids may be necessary 

to lower the pH level to an optimum range. In some water plants, the acidic reactions of the 

inorganic salts are taken advantage of when the raw water pH levels are higher than desired. 

In these instances, overfeed of the coagulant is intentionally induced in order for the 

coagulation process to occur in the optimum range. 

Effects of salts: Since no natural waters are completely pure, each will have various levels 

of cations and anions such as calcium, sodium, magnesium, iron, manganese, sulfate, 

chloride, phosphate, and others. Some of these ions may affect the efficiency of the 

coagulation process. Generally, mono and divalent cations such as sodium, calcium, and 

magnesium have little or no effect on the coagulation process. Trivalent cations do not have 

an adverse effect on the process in most instances. In fact, significant concentrations of 

naturally occurring iron in a water supply has resulted in the ability to feed lower than normal 

dosages of inorganic salt coagulants. 

Some anions can have a more pronounced effect. Generally, monovalent anions such as 

chloride have little effect on the coagulation process. As the concentration of the divalent 

anion sulfate in a water supply increases, the optimum pH range of the inorganic salt 

coagulants tends to broaden, generally toward the lower pH levels. As the concentration of 

phosphate ions increase, the optimum range of pH tends to shift to lower pH levels, without 

broadening. These effects could cause a disruption of the coagulation process if abrupt 

changes in the concentrations of these anions occur in the water supply. 

Nature of turbidity: The turbidity in natural surface waters is composed of a large number of 

sizes of particles. The sizes of particles can be changing constantly, depending on 

precipitation and manmade factors. When heavy rains occur, runoff into streams, rivers, and 

reservoirs occurs, causing turbidity levels to increase. In most cases, the particle sizes are 

relatively large and settle relatively quickly in both the water treatment plant and the source 

of supply. However, in some instances, fine, colloidal material may be present in the supply, 

which may cause some difficulty in the coagulation process. 

Generally, higher turbidity levels require higher coagulant dosages. However, seldom is the 

relationship between turbidity level and coagulant dosage linear. Usually, the additional 

coagulant required is relatively small when turbidities are much higher than normal due to 

higher collision probabilities of the colloids during high turbidities. Conversely, low turbidity 

waters can be very difficult to coagulate due to the difficulty in inducing collision between the 

colloids. In this instance, floc formation is poor, and much of the turbidity is carried directly to 

the filters. Organic colloids may be present in a water supply due to pollution, and these 

colloids can be difficult to remove in the coagulation process. In this situation, higher 

coagulant dosages are generally required. 

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Water temperature: Cold water temperatures can cause two factors which add to the 

difficulty of the coagulation process. As water temperatures approach freezing, almost all 

chemical reactions occur more slowly. It can be more difficult therefore to evenly disperse the 

coagulants into the water. As a result, the coagulant process becomes less efficient, and 

higher coagulant dosages are generally used to compensate for these effects. In addition, 

floc settling characteristics become poor due to the higher density of the water during near 

freezing temperatures. 

Mixing Effects: Poor or inadequate mixing results in an uneven dispersion of the coagulant. 

Unfortunately, many older plants were designed with mixing facilities which generally do not 

accomplish mixing in the most efficient manner. As a result, it becomes necessary to use 

higher than necessary dosages of coagulant to achieve an optimum level of efficiency in the 

process. The effects of low turbidity and cold water temperatures can tend to aggravate the 

lack of adequate mixing facilities in some plants. 

Effect of the coagulant: The choice of the proper coagulant for the given conditions is of 

critical importance in maintaining an efficient coagulation scheme under widely varying 

conditions. The chemicals most commonly used in the coagulation process are Aluminum 

Sulfate, Ferric Chloride, Ferric Sulfate, and Cationic Polymers. 

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Coagulants 

Aluminum Sulfate (Alum): Aluminum Sulfate is also known as alum, filter alum, and 

alumina sulfate. Alum is the most widely used coagulant. Alum is available in dry form as a 

powder or in lump form. It can also be purchased and fed as a liquid. Alum has no exact 

formula due to the varying water molecules of hydration which may be attached to the 

aluminum sulfate molecule. Once in water, alum can react with hydroxides, carbonates, 

bicarbonates, and other anions as discussed previously to form large, positively charged 

molecules. Carbon dioxide and sulfate are generally byproducts of these reactions. During 

the reactions, alum acts as an acid to reduce the pH and alkalinity of the water supply. It is 

important that sufficient alkalinity be present in the water supply for the various reactions to 

occur. 

On a theoretical basis, 1.0 mg/l of dry alum will react with: 

0.50 mg/l of natural alkalinity as calcium carbonate 

0.33 mg/l of 85% quicklime as calcium oxide 

0.39 mg/l of 95% hydrated lime as calcium hydroxide 

0.54 mg/l of soda ash as sodium carbonate 

Alum can be effective in the pH range of 5.5 to 7.8, but seems to work best in most water 

supplies in a pH range of 6.8 to 7.5. Below a pH range of 5.5, alkalinity in the water supply is 

generally insufficient. The aluminum ions become soluble rather than insoluble and do not 

participate in the hydration and olation reactions necessary to make the alum effective as a 

coagulant. In these instances the plant may experience higher than normal filtered water 

turbidities, and much of the aluminum will pass through the filters. 

When the pH level of the water is above 7.8 after the addition of the alum, the aluminum ions 

again become soluble, and the efficiency of coagulation is decreased. Under these 

conditions, aluminum ions again penetrate the filters, and post filtration alum coagulation can 

occur in the clear well and in the distribution system in some cases. 

Ferric Chloride (Ferric): Traditionally, ferric chloride has not been used widely as a 

coagulant, but this trend is not continuing. Ferric chloride is becoming more extensively used 

as a coagulant due partially to the fact that the material can be purchased as a liquid. 

Ferric chloride may also be purchased as an anhydrous solid. Liquid ferric chloride is highly 

corrosive, and must be isolated from all corrodible metals. Like ferric sulfate, ferric chloride 

exhibits a wide pH range for coagulation, and the ferric ion does not easily become soluble. 

As a result, many plants are replacing alum with ferric chloride to eliminate the penetration of 

aluminum ions through the plant filters. Ferric chloride also reacts as an acid in water to 

reduce alkalinity. 

Other inorganic coagulants are available, such as potash alum, ammonia alum, ferrous 

sulfate (copperas), and chlorinated copperas. None of these materials are widely used. 

Typical dosages of the inorganic coagulants range from 50 pounds per million gallons of 

water treated under ideal conditions to as high as 800 to 1000 pounds per million gallons of 

water treated under worst case conditions. 

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H2S Control – Traditional Wet Scrubbing using Chemicals 

The most common method of control of H2S gas is to pass the smelly gas through a vertical, 

packed bed wet scrubber. The air passes up the tower as the scrubbing liquid containing 

caustic (NaOH) and oxidizing agent (most often bleach or NaOCl, sodium hypochlorite) flows 

down the tower in the counter-current fashion. The high pH provided by the caustic drives the 

mass transfer from gas to liquid phase by solubolizing H2S as HS - bisulfide and S -2 sulfide 

ions. Once in solution, the reaction between hydrogen sulfide and oxidizing agent is almost 

instantaneous (assuming sufficient oxidizing agent is present). This reaction converts the 

sulfide to sulfate (SO4 -2 ) ion. The overall chemical reaction is described by the following 

equation: 

H2S + 4NaOCl + 2NaOH � Na2SO4 + 4NaCl + 2H2O 

Therefore, theoretically, for each molecule of H2S destroyed, four molecules of bleach and 

two molecules of caustic are consumed. However, the chemistry is not quite so simple, as 

partial oxidation of H2S also takes place which forms elemental sulfur: 

H2S + NaOCl � NaCl + H2O + S 

This reaction represents about 1% of the chemistry present in a wet scrubber. The presence 

of excess bleach helps to minimize the formation of elemental sulfur. But bleach is an 

expensive chemical. The use of two stage scrubbing is often employed both to minimize 

chemical consumption as well as to control sulfur deposits when scrubbing H2S. The first 

stage operates at 80% efficiency and uses a caustic only scrub at high pH (12.5). The air 

then passes to the second stage, where the remaining H2S is scrubbed with caustic / bleach 

solution at pH 9.5. The H2S present is destroyed at 99%+ efficiency. The blowdown from the 

2 nd stage, which will contain some amount of unsued NaOCl, is sent to the sump of the 1 st 

stage. In this way additional H2S is destroyed and maximum consumption of expensive 

oxidizing agent is assured. 

Never the less, there are losses of chemicals which cannot be prevented, which of course 

raise the cost of odor scrubbing. These losses are due to the facts that bleach, NaOCl, 

slowly decomposes in storage as well as the fact that some amount of caustic is constantly 

lost to CO2 absorption in both scrubbing stages. 

Emissions 

Volatile organic compounds (VOCs) are the primary air pollutants emitted from rendering 

operations. The major constituents that have been qualitatively identified as potential 

emissions include organic sulfides, disulfides, C-4 to C-7 aldehydes, trimethylamine, C-4 

amines, quinoline, dimethyl pyrazine, other pyrazines, and C-3 to C-6 organic acids. In 

addition, lesser amounts of C-4 to C-7 alcohols, ketones, aliphatic hydrocarbons, and 

aromatic compounds are potentially emitted. No quantitative emission data were presented. 

Historically, the VOCs are considered an odor nuisance in residential areas in close proximity 

to rendering plants, and emission controls are directed toward odor elimination. The odor 

detection threshold for many of these compounds is low; some as low as 1 part per billion 

(ppb). Of the specific constituents listed, only quinoline is classified as a hazardous air 

pollutant (HAP). In addition to emissions from rendering operations, VOCs may be emitted 

from the boilers used to generate steam for the operation. 

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Hard Water Section 

Water contains various amounts of dissolved minerals, some of which impart a quality known 

as hardness. Consumers frequently complain about problems attributed to hard water, such 

as the formation of scale on cooking utensils and hot water heaters. In this document we will 

examine the occurrence, and effects, of hard water and the hard water treatment or softening 

process that removes the hardness-causing minerals. The precipitation process most 

frequently used is generally known as the lime process or lime soda process. Because of the 

special facilities required and the complexity of the process, it is generally applicable only to 

medium- or large-size water systems where all treatment can be accomplished at a central 

location. This process will provide softened water at the lowest cost. Lime softening can be 

used for treatment of either groundwater or surface water sources. 

The other commonly used method of softening involves 

the ion exchange process. This process has the 

advantages of a considerably lower initial cost and ease 

of use by small systems or by large systems at multiple 

locations. The principal disadvantage is that operating 

costs are considerably higher. Ion exchange processes 

can typically be used for direct treatment of groundwater, 

so long as turbidity and iron levels are not 

excessive. For treatment of surface water, the process 

normally must be preceded by conventional treatment. 

Softening can also be accomplished using membrane 

technology, electrodialysis, distillation, and freezing. Of 

these, membrane methods seem to have the greatest 

potential. 

Distillers 

Various sizes of distillers are available for home use. 

They all work on the principle of vaporizing water and 

then condensing the vapor. In the process, dissolved solids such as salt, metals, minerals, 

asbestos fibers, and other particles are removed. Some organic chemicals are also removed, 

but those that are more volatile are often vaporized and condensed with the product water. 

Distillers are effective in killing all microorganisms. 

The principal problem with a distiller is that a small unit 

can produce only 2-3 gal (7.5 -11 Lt) a day, and that the 

power cost for operation will be substantially higher 

than the operating cost of other types of treatment 

devices. 

Water Distillers have a high energy cost (approximately 

20-30 cents per gallon). They must be carbon filtered 

before and/or after to remove volatile chemicals. It is 

considered "dead" water because the process removes 

all extra oxygen and energy. It has no taste. It is still 

second only to reverse osmosis water for health. Diet 

should be rich in electrolytes, as the aggressive nature of distilled water can "leach" 

electrolytes from the body. 

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Occurrence of Hard Water 

Hard water is caused by soluble, divalent, metallic cations, (positive ions having valence of 

2). The principal chemicals that cause water hardness are calcium (Ca) and magnesium 

(Mg). Strontium, aluminum, barium, and iron are usually present in large enough 

concentrations to contribute significantly to the total hardness. 

Water hardness varies considerably in different geographic areas of the contiguous 48 

states. This is due to different geologic formations, and is also a function of the contact time 

between water and limestone deposits. Magnesium is dissolved as water passes over and 

through dolomite and other magnesium-bearing minerals. Because groundwater is in contact 

with these formations for a longer period of time than surface water, groundwater is normally 

harder than surface water. 

Expressing Water Hardness Concentration 

Water hardness is generally expressed as a concentration of calcium carbonate, in terms of 

milligrams per liter as CaCO3. The degree of hardness that consumers consider 

objectionable will vary, depending on other qualities of the water and on the hardness to 

which they have become accustomed. We will show two different classifications of the 

relative hardness of water: 

Comparative classifications of water for softness and hardness 

Classification mg/L as CaCO3 * mg/L as CaCO3 + 

Soft 0 – 75 0 – 60 

Moderately hard 75 – 150 61 – 120 

Hard 150 – 300 121 – 180 

Very hard Over 300 Over 180 

Source: Adapted from sawyer 1960 and Briggs and Ficke 1977. 

* Per Sawyer (1960) 

+ Per Briggs and Ficke (1977) 

Types of Water Hardness 

Hardness can be categorized by either of two methods: calcium versus magnesium hardness 

and carbonate versus non-carbonate hardness. The calcium-magnesium distinction is based 

on the minerals involved. Hardness caused by calcium is called calcium hardness, 

regardless of the salts associated with it, which include calcium sulfate (CaSO4), calcium 

chloride (CaCl2), and others. Likewise, hardness caused by magnesium is called magnesium 

hardness. Calcium and magnesium are normally the only significant minerals that cause 

harness, so it is generally assumed that 

Total harness = calcium hardness + magnesium hardness 

The carbonate-noncarbonate distinction, however, is based on hardness from either the 

bicarbonate salts of calcium or the normal salts of calcium and magnesium involved in 

causing water hardness. Carbonate hardness is caused primarily by the bicarbonate salts of 

calcium and magnesium, which are calcium bicarbonate, Ca(HCO3)2, and magnesium 

bicarbonate Mg(HCO3)2. Calcium and magnesium combined with carbonate (CO3) also 

contribute to carbonate hardness. 

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Noncarbonate hardness is a measure of calcium and magnesium salts other than carbonate 

and bicarbonate salts. These salts are calcium sulfate, calcium chloride, magnesium sulfate 

(MgSO4), and magnesium chloride (MgCl2). Calcium and magnesium combined with nitrate 

may also contribute to noncarbonate hardness, although it is a very rare condition. For 

carbonate and noncarbonate hardness, 

Total hardness = carbonate hardness + noncarbonate hardness 

When hard water is boiled, carbon dioxide (CO2) is driven off, and Bicarbonate salts of 

calcium and magnesium then settle out of the water to form calcium and magnesium 

carbonate precipitates. These precipitates form the familiar chalky deposits on teapots. 

Because it can be removed by heating, carbonate hardness is sometimes called 

“Temporary hardness.” Because noncarbonated hardness cannot be removed or 

precipitated by prolonged boiling, it is sometimes called “permanent hardness.” 

Objections to Hard Water 

Scale Formation 

Hard water forms scale, usually calcium carbonate, which causes a variety of problems. Left 

to dry on the surface of glassware and plumbing fixtures, including showers doors, faucets, 

and sink tops; hard water leaves unsightly white scale known as water spots. Scale that 

forms on the inside of water pipes will eventually reduce the flow capacity or possibly block it 

entirely. Scale that forms within appliances and 

water meters causes wear on moving parts. 

When hard water is heated, scale forms much 

faster. In particular, when the magnesium 

hardness is more than about 40 mg/l (as 

CaCO3), magnesium hydroxide scale will 

deposit in hot water heaters that are operated 

at normal temperatures of 140-150 o F (60- 

66 o C). A coating of only 0.04 in. (1 mm) of 

scale on the heating surfaces of a hot water 

heater creates an insulation effect that will 

increase heating costs by about 10 percent. 

Effect on Soap 

The historical objection to hardness has been 

its effect on soap. Hardness ions form precipitates with soap, causing unsightly “curd,” such 

as the familiar bathtub ring, as well as reduced efficiency in washing and laundering. To 

counteract these problems, synthetic detergents have been developed and are now used 

almost exclusively for washing clothes and dishes. 

These detergents have additives known as sequestering agents that “tie up” the hardness 

ions so that they cannot form the troublesome precipitates. Although modern detergents 

counteract many of the problems of hard water, many customers prefer softer water. These 

customers can install individual softening units or use water from another source, such as a 

cistern, for washing. 

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Water Softening 

Water softening is a method of removing from water the minerals that make it hard. Hard 

water does not dissolve soap readily. It forms scale in pipes, boilers, and other equipment in 

which it is used. The principal methods of softening water are the lime soda process and the 

ion exchange process. 

In the lime soda process, soda ash and lime are added to the water in amounts determined 

by chemical tests. These chemicals combine with the calcium and magnesium in the water to 

make insoluble compounds that settle to the bottom of the water tank. 

In the ion exchange process, the water filters through minerals called zeolites. As the 

water passes through the filter, the 

sodium ions in the zeolite are exchanged 

for the calcium and magnesium ions in 

the water, and the water is softened. After 

household softeners become exhausted, 

a strong solution of sodium chloride 

(salt) is passed through the filter to 

replace the sodium that has been lost. 

The use of two exchange materials 

makes it possible to remove both metal 

and acid ions from water. Some cities and 

towns, however, prohibit or restrict the use of ion exchange equipment on drinking water, 

pending the results of studies on how people are affected by the consumption of the added 

sodium in softened water. The containers hold the resin for the deionization. Calcium and 

magnesium in water create hard water, and high levels can clog pipes. The best way to 

soften water is to use a water softener unit connected into the water supply line. You may 

want to consider installing a separate faucet for unsoften water for drinking and cooking. 

Water softening units also remove iron. 

The most common way to soften household water is to use a water softener. Softeners may 

also be safely used to remove up to about 5 milligrams per liter of dissolved iron if the water 

softener is rated for that amount of iron removal. Softeners are automatic, semi-automatic, or 

manual. Each type is available in several sizes and is rated on the amount of hardness it can 

remove before regeneration is necessary. Using a softener to remove iron in naturally soft 

water is not advised; a green-sand filter is a better method. When the resin is filled to 

capacity, it must be recharged. Fully automatic softeners regenerate on a preset schedule 

and return to service automatically. Regeneration is usually started by a preset time clock; 

some units are started by water use meters or hardness detectors. 

Semi-automatic softeners have automatic controls for everything except for the start of 

regeneration. Manual units require manual operation of one or more valves to control back 

washing, brining and rinsing. In many areas, there are companies that provide a water 

softening service. For a monthly fee the company installs a softener unit and replaces it 

periodically with a freshly charged unit. 

The principle behind water softening is really just simple chemistry. A water softener contains 

resin beads which hold electrically charged ions. When hard water passes through the 

softener, calcium and magnesium ions are attracted to the charged resin beads. It's the 

resulting removal of calcium and magnesium ions that produces "soft water." 

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The diagram shows the exchange that takes place during the water softening process. When 

the resin beads in your softener become saturated with calcium and magnesium ions, they 

need to be recharged. Sodium ions from the water softening salt reactivate the resin beads 

so they can continue to do their job. Without sufficient softening salt, your water softener is 

less efficient. As a rule, you should check your water softener once a week to be sure the 

salt level is always at least one quarter full. 

Conventional Household Water Softener 

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French physicist Nollet and 

his first RO unit. 

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Membrane Filtration Processes 

In 1748, the French physicist Nollet first noted that water would diffuse through a pig bladder 

membrane into alcohol. This was the discovery of osmosis, a process in which water from a 

dilute solution will naturally pass through a porous membrane into a concentrate solution. 

Over the years, scientists have attempted to develop a membrane that would be useful in 

industrial processes, but it wasn’t until the late 1950s that membranes were produced that 

could be used for what is known as reverse osmosis. In reverse osmosis, water is forced to 

move through a membrane from a concentrate solution to a dilute solution. 

Since that time, continual improvements and new developments have been made in 

membrane technology, resulting in ever-increasing uses in many industries. In potable water 

treatment, membranes have been used for desalinization, removal of dissolved inorganic and 

organic chemicals, water softening, and removal of the fine solids. 

In particular, membrane technology enables some water systems having contaminated water 

sources to meet new, more stringent regulations. In some cases, it can also allow secondary 

sources, such as brackish groundwater, to be used. There is great potential for the 

continuing wide use of membrane filtration processes in potable water treatment, especially 

as technology is improved and costs are reduced. 

Description of Membrane Filtration Processes 

In the simplest membrane processes, water is forced through a porous membrane under 

pressure, while suspended solids, large molecules, or ions are held back or rejected. 

Types of Membrane Filtration 

Processes 

The two general classes of membrane processes, 

based on the driving force used to make the 

process work, are: 

� Pressure-driven processes 

� Electric-driven processes 

Pressure-Driven Processes 

The four general membrane processes that 

operate by applying pressure to the raw water are: 

� Microfiltration 

� Ultrafiltration 

� Nanofiltration 

� Reverse Osmosis 

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Microfiltration 

Microfiltration (MF) is a process in which water is forced under pressure through a porous 

membrane. Membranes with a pore size of 0.45 m are normally used; this size is relatively 

large compared with the other membrane filtration processes. This process has not been 

generally applicable to drinking water treatment because it either does not remove 

substances that require removal from potable water, or the problem substances can be 

removed more economically using other processes. 

The current primary use of MF is by industries to remove very fine particles from process 

water, such as in electronic manufacturing. In addition, the process has also been used as a 

pretreatment for other membrane processes. In particular, Reverse Osmosis (RO) 

membranes are susceptible to clogging or binding unless the water being processed is 

already quite clean. 

However, in recent years, microfiltration has been proposed as a filtering method for particles 

resulting from the direct filtration process. Traditionally, this direct filtration process has used 

the injection of coagulants such as alum or polymers into the raw water stream to remove 

turbidity such as clay or silts. The formed particles were then removed by rapid sand filters. 

Their suggested use is to improve filtering efficiency, especially for small particles that could 

contain bacterial and protozoan life. 

Ultrafiltration 

Ultrafiltration (UF) is a process that uses a membrane with a pore size generally below 0.1 

m. The smaller pore size is designed to remove colloids and substances that have larger 

molecules, which are called high-molecular-weight materials. UF membranes can be 

designed to pass material that weigh less than or equal to a certain molecular weight. This 

weight is called the molecular weight cutoff (MWC) of the membrane. Although UF does not 

generally work well for removal of salt or dissolved solids, it can be used effectively for 

removal or most organic chemicals. 

Nanofiltration 

Nanofiltration (NF) is a process using membrane that will reject even smaller molecules than 

UF. The process has been used primarily for water softening and reduction of total dissolved 

solids (TDS). NF operates with less pressure than reverse osmosis and is still able to remove 

a significant proportion of inorganic and organic molecules. This capability will undoubtedly 

increase the use of NF for potable water treatment. 

Reverse Osmosis 

Reverse Osmosis (RO) is a membrane process that has the highest rejection capability of all 

the membrane processes. These RO membranes have very low pore size that can reject 

ions at very high rates, including chloride and sodium. Water from this process is very pure 

due to the high reject rates. The process has been used primarily in the water industry for 

desalinization of seawater because the capital and operating costs are competitive with other 

processes for this service. 

The RO also works for most organic chemicals, radionuclides and microorganisms. For 

industrial water uses such as semiconductor manufacturing, is also an important RO 

process. RO is discussed in more detail later. 

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Membrane Configurations 

Electric-Driven Processes 

There are two membrane processes that purify a water stream by using an electric current to 

move ions across a membrane. 

These processes are 

� Electrodialysis 

� Electrodialysis Reversal 

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Electrodialysis 

Electrodialysis (ED) is a process in which ions are transferred through a membrane as a 

result of direct electric current applied to the solution. The current carries the ions through a 

membrane from the less concentrated solution to the more concentrated one. 

Electrodialysis Reversal 

Electrodialysis Reversal (EDR) is a process similar to ED, except that the polarity of the 

direct current is periodically reversed. The reversal in polarity reverses the flow of ions 

between demineralizing compartments, which provides automatic flushing of scale-forming 

materials from the membrane surface. 

As a result, EDR can often be used with little or no pretreatment of feedwater to prevent 

fouling. So far, ED and EDR have been used at only a few locations for drinking water 

treatment. 

GAC inside Carbon vessels like these are often used for taste and odor control. 

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Reverse Osmosis 

Osmosis is a natural phenomenon in which a liquid - water in this case - passes through a 

semi-permeable membrane from a relatively dilute solution toward a more concentrated 

solution. This flow produces a measurable pressure, called osmotic pressure. 

If pressure is applied to the more concentrated solution, and if that pressure exceeds the 

osmotic pressure, water flows through the membrane from the more concentrated solution 

toward the dilute solution. This process, called reverse osmosis, or RO, removes up to 98% 

of dissolved minerals, and virtually 100% of colloidal and suspended matter. RO produces 

high quality water at low cost compared to other purification processes. 

The membrane must be physically strong to stand up to high osmotic pressure - in the case 

of sea water, 2500 kg/m. Most membranes are made of cellulose acetate or polyamide 

composites cast into a thin film, either as a sheet or fine hollow fibers. 

The membrane is constructed into a cartridge called a reverse osmosis module. 

RO Skid 

After filtration to remove suspended particles, incoming water is pressurized with a pump to 

200 - 400 psi (1380 - 2760 kPa) depending on the RO system model. 

This exceeds the water's osmotic pressure. A portion of the water (permeate) diffuses 

through the membrane, leaving dissolved salts and other contaminants behind with the 

remaining water where they are sent to drain as waste (concentrate). 

RO 

Pretreatment is important because it influences permeate quality and quantity. It also affects 

the module's life because many water-borne contaminants can deposit on the membrane 

and foul it. Generally, the need for pretreatment increases as systems become larger and 

operate at higher pressures, and as permeate quality requirements become more 

demanding. Because reverse osmosis is the principal membrane filtration process used in 

water treatment, it is described here in greater detail. 

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To understand Reverse Osmosis, one must begin by understanding the process of osmosis, 

which occurs in nature. In living things, osmosis is frequently seen. The component parts 

include a pure or relatively pure water solution and a saline or contaminated water solution, 

separated by a semi-permeable membrane, and a container or transport mechanism of some 

type. 

The semi-permeable membrane is so designated because it permits certain elements to 

pass through, while blocking others. The elements that pass through include water, usually 

smaller molecules of dissolved solids, and most gases. The dissolved solids are usually 

further restricted based on their respective electrical charge. In osmosis, naturally occurring 

in living things, the pure solution passes through the membrane until the osmotic pressure 

becomes equalized, at which point osmosis ceases. The osmotic pressure is defined as the 

pressure differential required to stop osmosis from occurring. This pressure differential is 

determined by the total dissolved solids content of the saline solution, or contaminated 

solution on one side of the membrane. The higher the content of dissolved solids, the higher 

the osmotic pressure. Each element that may be dissolved in the solution contributes to the 

osmotic pressure, in that the molecular weight of the element affects the osmotic pressure. 

Generally, higher molecular weights result in higher osmotic pressures. Hence, the formula 

for calculating osmotic pressure is very complex. However, approximate osmotic pressures 

are usually sufficient to design a system. Common tap water, as found in most areas, may 

have an osmotic pressure of about 10 PSI (Pounds per Square Inch), or about 1.68 Bar. 

Seawater at 36,000 PPM typically has an osmotic pressure of about 376 PSI (26.75 Bar). 

Thus, to reach the point at which osmosis stops for tap water, a pressure of 10 PSI would 

have to be applied to the saline solution. To stop osmosis in seawater, a pressure of 376 

PSI would have to be applied to the seawater side of the membrane. Several decades ago, 

U.S. Government scientists had the idea that the principles of osmosis could be harnessed to 

purify water from various sources, including brackish water and seawater. In order to 

transform this process into one that purifies water, osmosis would have to be reversed, and 

suitable synthetic membrane materials would have to be developed. Additionally, ways of 

configuring the membranes would have to be engineered to handle a continuous flow of raw 

and processed water without clogging or scaling the membrane material. 

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These ideas were crystallized and, fueled by U.S. Government funding, usable membrane 

materials and designs resulted. One of the membrane designs was the spiral wound 

membrane element. This design enabled the engineers to construct a membrane element 

that could contain a generous amount of membrane area in a small package, and to permit 

the flow of raw water to pass along the length of the membrane. 

This permits flows and pressures to be developed to the point that ample processed or 

purified water is produced, while keeping the membrane surface relatively free from 

particulate, colloidal, bacteriological or mineralogical fouling. 

The design features a perforated tube in the center of the element, called the product or 

permeate tube. Wound around this tube are one or more "envelopes" of membrane material, 

opening at the permeate tube. Each envelope is sealed at the incoming and exiting edge. 

Thus, when water penetrates or permeates though the membrane, it travels, aided by a fine 

mesh called the permeate channel, around the spiral and collects in the permeate tube. The 

permeate or product water is collected from the end of each membrane element, and 

becomes the product or result of the purification process. 

Meanwhile, as the raw water flows along the "brine channel" or coarse medium provided to 

facilitate good flow characteristics, it gets more and more concentrated. This concentrated 

raw water is called the reject stream or concentrate stream. It may also be called brine if it is 

coming from a salt water source. The concentrate, when sufficient flows are maintained, 

serves to carry away the impurities removed by the membrane, thus keeping the membrane 

surface clean and functional. This is important, as buildup on the membrane surface, called 

fouling, impedes or even prevents the purification process. 

The membrane material itself is a special thin film composite (TFC) polyamide material, cast 

in a microscopically thin layer on another, thicker cast layer of Polysulfone, called the 

microporous support layer. The microporous support layer is cast on sheets of paper-like 

material that are made from synthetic fibers such as polyester, and manufactured to the 

required tolerances. 

Each sheet of membrane material is inspected at special light tables to ensure the quality of 

the membrane coating, before being assembled into the spiral wound element design. To 

achieve Reverse Osmosis, the osmotic pressure must be exceeded, and to produce a 

reasonable amount of purified water, the osmotic pressure is generally doubled. Thus with 

seawater osmotic pressure of 376 PSI, a typical system operating pressure is about 800 PSI. 

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Factors that affect the pressure required include raw water temperature, raw water TDS 

(Total Dissolved Solids), membrane age, and membrane fouling. 

The effect of temperature is that with higher temperatures, the salt passage increases, flux 

(permeate flow) increases, and operating pressure required is lower. With lower 

temperatures, the inverse occurs, in that salt passage decreases (reducing the TDS in the 

permeate or product water), while operating pressures increase. Or, if operating pressures 

do not increase, then the amount of permeate or product water is reduced. In general, 

Reverse Osmosis (R/O) systems are designed for raw water temperatures of 25° C (77° F). 

Higher temperatures or lower temperatures can be accommodated with appropriate 

adjustments in the system design. 

Membranes are available in "standard rejection" or "high rejection" models for seawater 

and brackish water. The rejection rate is the percentage of dissolved solids rejected, or 

prevented from passing through the membrane. For example, a membrane with a rejection 

rate of 99% (usually based on Na (Sodium)) will allow only 1% of the concentration of 

dissolved solids to pass through into the permeate. Hence, product water from a source 

containing 10,000 PPM would have 100 PPM remaining. Of course, as the raw water is 

processed, the concentrations of TDS increase as it passes along the membrane’s length, 

and usually multiple membranes are employed, with each membrane in the series seeing 

progressively higher dissolved solids levels. 

Typically, starting with seawater of 36,000 PPM, standard rejection membranes produce 

permeate below 500 PPM, while high rejection membranes under the same conditions 

produce drinking water TDS of below 300 PPM. There are many considerations when 

designing R/O systems that competent engineers are aware of. These include optimum 

flows and pressures, optimum recovery rates (the percentage of permeate from a given 

stream of raw water), prefiltration and other pretreatment considerations, and so forth. 

Membrane systems in general cannot handle the typical load of particulate contaminants 

without prefiltration. Often, well designed systems employ multiple stages of prefiltration, 

tailored to the application, including multi-media filtration and one or more stages of cartridge 

filtration. Usually the last stage would be 5m or smaller, to provide sufficient protection for 

the membranes. 

R/O systems typically have the following components: 

A supply pump or pressurized raw water supply; prefiltration in one or more stages; chemical 

injection of one or more pretreatment agents may be added; a pressure pump suited to the 

application, sized and driven appropriately for the flow and pressure required; a membrane 

array including one or more membranes installed in one or more pressure tubes (also called 

pressure vessels, R/O pressure vessels, or similar); various gauges and flow meters; a 

pressure regulating valve, relief valve(s) and/or safety pressure switches; and possibly some 

form of post treatment. Post treatment should usually include a form of sterilization such as 

Chlorine, Bromine, Ultra-Violet (U-V), or Ozone. Other 

types of post treatment may include carbon filters, pH 

adjustment, or mineral injection for some applications. 

Right side-Packaged treatment skid instrumentation, 

UV, and softening. 

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Granular Activated Carbon / Powdered Activated Carbon 

Along with aeration, granular activated carbon (GAC) and powdered activated carbon (PAC) 

are suitable treatments for removal of organic contaminants such as VOCs, solvents, PCBs, 

herbicides and pesticides. Activated carbon is carbon that has been exposed to a very high 

temperature, creating a vast network of pores with a very large internal surface area; one 

gram of activated carbon has a surface area equivalent to that of a football field. It removes 

contaminants through adsorption, a process in which dissolved contaminants adhere to the 

surface of the carbon particles. 

GAC can be used as a replacement for existing media (such as sand) in a conventional filter 

or it can be used in a separate contactor such as a vertical steel pressure vessel used to hold 

the activated carbon bed. After a period of a few months or years, depending on the 

concentration of the contaminants, the surface of the pores in the GAC can no longer adsorb 

contaminants and the carbon must be replaced. Several operational and maintenance factors 

affect the performance of granular activated carbon. Contaminants in the water can occupy 

adsorption sites, whether or not they are targeted for removal. Also, adsorbed contaminants 

can be replaced by other contaminants with which GAC has a greater affinity, so their 

presence might interfere with removal of contaminants of concern. 

A significant drop in the contaminant level in influent water can cause a GAC filter to desorb, 

or slough off adsorbed contaminants, because GAC is essentially an equilibrium process. As 

a result, raw water with frequently changing contaminant levels can result in treated water of 

unpredictable quality. Bacterial growth on the carbon is another potential problem. Excessive 

bacterial growth may cause clogging and higher bacterial counts in the treated water. The 

disinfection process must be carefully monitored in order to avoid this problem. 

Powdered activated carbon consists of finely ground particles and exhibits the same 

adsorptive properties as the granular form. PAC is normally applied to the water in a slurry 

and then filtered out. The addition of PAC can improve the organic removal effectiveness of 

conventional treatment processes and also remove tastes and odors. The advantages of 

PAC are that it can be used on a 

short-term or emergency basis 

with conventional treatment, it 

creates no headloss, it does not 

encourage microbial growth, 

and it has relatively small capital 

costs. The main disadvantage is 

that some contaminants require 

large doses of PAC for removal. 

It is also somewhat ineffective in 

removing natural organic matter 

due to the competition from 

other contaminants for surface 

adsorption and the limited 

contact time between the water 

and the carbon. 

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Clean-In-Place 

Some very low cost R/O systems may dispense with most of the controls and instruments. 

However, systems installed in critical applications should be equipped with a permeate or 

product flow meter, a reject, concentrate or brine flow meter; multiple pressure gauges to 

indicate the pressure before and after each filtration device, and the system operation 

pressure in the membrane loop; preferably both before and after the membrane array. Another 

feature found in better systems is a provision to clean the membranes in place, commonly 

known as a "Clean In Place" (CIP) system. Such a system may be built right into the R/O 

system or may be provided as an attachment for use as required. 

Reverse Osmosis has proven to be the most reliable and cost effective method of desalinating 

water, and hence its use has become more and more widespread. Energy consumption is 

usually some 70% less than for comparable evaporation technologies. Advancements have 

been made in membrane technology, resulting in stable, long-lived membrane elements. 

Component parts have been improved as well, reducing maintenance and down time. 

Additional advancements in pretreatment have been made in recent years, further extending 

membrane life and improving performance. 

Reverse Osmosis delivers product water or permeate having essentially the same temperature 

as the raw water source (an increase of 1° C or 1.8° F may occur due to pumping and friction 

in the piping). This is more desirable than the hot water produced by evaporation technologies. 

R/O Systems can be designed to deliver virtually any required product water quality. For these 

and other reasons, R/O is usually the preferred method of desalination today. 

Reverse osmosis, also known as hyperfiltration, is the finest filtration known. This process will 

allow the removal of particles as small as ions from a solution. Reverse osmosis is used to 

purify water and remove salts and other impurities in order to improve the color, taste, or 

properties of the fluid. It can be used to purify fluids such as ethanol and glycol, which will pass 

through the reverse osmosis membrane, while rejecting other ions and contaminants from 

passing. The most common use for reverse osmosis is in purifying water. It is used to produce 

water that meets the most demanding specifications that are currently in place. 

Reverse osmosis uses a membrane that is semi-permeable, allowing the fluid that is being 

purified to pass through it, while rejecting the contaminants that remain. Most reverse osmosis 

technology uses a process known as cross-flow to allow the membrane to continually clean 

itself. As some of the fluid passes through the membrane the rest continues downstream, 

sweeping the rejected species away from the membrane. The process of reverse osmosis 

requires a driving force to push the fluid through the membrane, and the most common force is 

pressure from a pump. The higher the pressure, the larger the driving force. As the 

concentration of the fluid being rejected increases, the driving force required to continue 

concentrating the fluid increases. 

Reverse osmosis is capable of rejecting bacteria, salts, sugars, proteins, particles, dyes, and 

other constituents that have a molecular weight of greater than 150-250 Daltons. The 

separation of ions with reverse osmosis is aided by charged particles. This means that 

dissolved ions that carry a charge, such as salts, are more likely to be rejected by the 

membrane than those that are not charged, such as organics. The larger the charge and the 

larger the particle, the more likely it will be rejected. 

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Reverse Osmosis, when properly configured with sediment, carbon and/or carbon block 

technology, produces pure water that is clearly the body's choice for optimal health. It is the 

best tasting because it is oxygen-rich. 

A Reverse Osmosis System removes virtually all of the following: bad taste, odor, turbidity, 

organic compounds, herbicides, insecticides, pesticides, chlorine and THM's, bacteria, virus, 

cysts, parasites, arsenic, heavy metals, lead, cadmium, aluminum, dissolved solids, sodium, 

calcium, magnesium, inorganic dead dirt minerals, fluoride, sulfates, nitrates, phosphates, 

detergents, radioactivity and asbestos. 

Ozone 

Ozone (O3) is probably the strongest oxidizing agent available for water treatment. Although it 

is widely used throughout the world, is has not found much application in the United States. 

Ozone is obtained by passing a flow of air or oxygen between two electrodes that are 

subjected to an alternating current in the order of 10,000 to 20,000 volts. 

3O2 + electrical discharge → 2O3� 

Liquid ozone is very unstable and can readily explode. As a result, it is not shipped and must 

be manufactured on-site. Ozone is a light blue gas at room temperature. It has a self-policing 

pungent odor similar to that sometimes noticed during and after heavy electrical storms. In 

use, ozone breaks down into oxygen and nascent oxygen. 

O3 = O2 + O 

It is the nascent oxygen that produces the high oxidation, disinfections, and even sterilization. 

Each water has its own ozone demand, in the order of 0.5 ppm to 5.0 ppm. Contact time, 

temperature, and pH of the water are factors in determining Ozone demand. Ozone acts as a 

complete disinfectant. It is an excellent aid to the flocculation and coagulation process, and will 

remove practically all color, taste, odor, iron, and manganese. It does not form chloramines or 

THMs, and while it may destroy some THMs, it may produce other byproducts when followed 

by chlorination. Ozone is not practical for complete removal of chlorine or chloramines, or of 

THM and other inorganics. Further, because of the possibility of formation of other 

carcinogens (such as aldehydes or phthalates) it falls into the same category as other 

disinfectants, because it can produce DBPs. 

Ozone Generator. 

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Turbidity 

One physical characteristic of water. A measure of the cloudiness of water caused by 

suspended particles. The cloudy appearance of water caused by the presence of tiny particles. 

High levels of turbidity may interfere with proper water treatment and monitoring. If high 

quality raw water is low in turbidity, there will be a reduction in water treatment costs. Turbidity 

is undesirable because it causes health hazards. An MCL for turbidity established by the EPA 

because turbidity interferes with disinfection. This characteristic of water changes the most 

rapidly after a heavy rainfall. The following conditions may cause an inaccurate measure of 

turbidity; the temperature variation of a sample, a scratched or unclean sample tube in the 

nephelometer and selecting an incorrect wavelength of a light path. 

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Ultraviolet Radiation 

The enormous temperatures on the sun create ultraviolet (UV) rays in great amounts, and this 

radiation is so powerful that all life on earth would be destroyed if these rays were not 

scattered by the atmosphere and filtered out by the layers of ozone gas that float some 20 

miles above the earth. 

This radiation can be artificially produced by sending 

strong electric currents thorough various substances. 

A sun lamp, for example, sends out UV rays that, 

when properly controlled, result in a suntan. Of 

course, too much will cause sunburn. 

The UV lamp that can be used for the disinfection of 

water depends upon the low-pressure mercury vapor 

lamp to produce the ultraviolet energy. A mercury 

vapor lamp is one in which an electric arc is passed through an inert gas. This, in turn, will 

vaporize the mercury contained in the lamp resulting in the production of UV rays. 

The lamp itself does not come into direct contact with the water, The lamp is placed inside a 

quartz tube, and the water is in contact with the outside of the quartz tube. Quartz is used in 

this case since practically none of the UV rays are absorbed by the quartz, allowing all of the 

rays to reach the water. Ordinary glass cannot be used since it will absorb the UV rays, 

leaving little for disinfection. The water flows around the quartz tube. The UV sterilizer will 

consist of a various number of lamps and tubes, depending upon the amount of water to be 

treated. As water enters the sterilizer, it is given a tangential flow pattern so that the water 

spins over and around the quartz sleeves. In this way, the microorganisms spend maximum 

time in contact with the outside of the quartz tube and the source of the UV rays. The basic 

design flow of water of certain UV units is in the order of 2.0 gpm for each inch of the lamp. 

Further, the units are designed, so the contact or retention time of the water in the unit is not 

less than 15 seconds. 

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Most manufacturers claim UV lamps have a life of about 7,500 hours, which is about 1 year’s 

time. The lamp must be replaced when it loses about 40% to 50% of its UV output; in any 

installation this is determined by means of a photoelectric cell and a meter that shows the 

output of the lamp. Each lamp is outfitted with its own photoelectric cell, and an alarm that will 

be activated when the penetration drops to a preset level. 

Ultraviolet radiation is an excellent disinfectant that is highly effective against viruses, molds, 

and yeasts; and it is safe to use. It adds no chemicals to the water, it leaves no residual, and it 

does not form THMs. It is used to remove traces of ozone and chloramines from the finished 

water. Alone, UV radiation will not remove precursors, but in combination with ozone, it is said 

to be effective in the removal of THM precursors and THMs. 

The germicidal effect of UV is thought to be associated with its absorption by various organic 

components essential to the cell’s function. For effective use of ultraviolet, the water to be 

disinfected must be clean and free of any suspended solids. The water must also be colorless 

and free of any colloids, iron, manganese, taste, and odor. These are conditions that must be 

met. Also, although water may appear to be clear, such substances as excesses of chlorides, 

bicarbonates, and sulfates affect absorption of the ultraviolet rays. These parameters will 

probably require at least filtration of one type or another. The UV manufacturer will, of course, 

stipulate which pretreatment may be necessary. 

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Removal of Disinfection By-Products 

Disinfectant 

Disinfectant Byproduct 

Disinfectant By-product Removal 

Chlorine (HOCl) Trialomethane (THM) Granular Activated Carbon (GAC), 

resins, controlled coagulation, 

aeration. 

Chloramine GAC-UV 

Chlorophenol GAC 

Chloramine (NHxCly) Probably no THM GAC 

Others? UV? 

Chlorine dioxide (ClO2) Chlorites 

Use of Fe2+ in coagulation, RO, ion- 

Chlorates 

exchange 

Permanganate (KMnO4) No THMs 

Ozone (O3) Aldehydes, 

Carboxylics, 

Phthalates 

GAC 

Ultraviolet (UV) None known GAC 

The table indicates that most of the disinfectants will leave a by-product that is or would 

possibly be inimical to health. This may aid with a decision as to whether or not precursors 

should be removed before these disinfectants are added to water. 

If it is decided that removal of precursors is needed, research to date indicates that this 

removal can be attained through the application of controlled chlorination plus coagulation and 

filtration, aeration, reverse osmosis, nanofiltration, GAC or combinations of other processes. 

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Modern Water Treatment Disinfectants 

Many water suppliers add a disinfectant to drinking water to kill germs such as Giardia and e 

coli. Especially after heavy rainstorms, your water system may add more disinfectant to 

guarantee that these germs are killed. 

Chlorine. Some people who use drinking water containing chlorine well in excess of EPA 

standards could experience irritating effects to their eyes and nose. Some people who drink 

water containing chlorine well in excess of EPA standards could experience stomach 

discomfort. 

Chloramine. Some people who use drinking water containing chloramines well in excess of 

EPA standards could experience irritating effects to their eyes and nose. Some people who 

drink water containing chloramines well in excess of EPA standards could experience 

stomach discomfort or anemia. 

Chlorine Dioxide. Some infants and young children who drink water containing chlorine 

dioxide in excess of EPA standards could experience nervous system effects. Similar effects 

may occur in fetuses of pregnant women who drink water containing chlorine dioxide in 

excess of EPA standards. Some people may experience anemia. 

Disinfectant alternatives will include Ozone and Ultraviolet light. You will see an 

increase of these technologies in the near future. 

Disinfection Byproducts (DBPS) 

Disinfection byproducts form when disinfectants 

added to drinking water to kill germs react with 

naturally-occurring organic matter in water. 

Total Trihalomethanes. Some people who 

drink water containing trihalomethanes in excess 

of EPA standards over many years may 

experience problems with their liver, kidneys, or 

central nervous systems, and may have an 

increased risk of getting cancer. 

Haloacetic Acids. Some people who drink 

water containing haloacetic acids in excess of 

EPA standards over many years may have an 


Bromate. Some people who drink water containing bromate in excess of EPA standards 

over many years may have an increased risk of getting cancer. 

Chlorite. Some infants and young children who drink water containing chlorite in excess of 

EPA standards could experience nervous system effects. Similar effects may occur in 

fetuses of pregnant women who drink water containing chlorite in excess of EPA standards. 

Some people may experience anemia. 

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Corrosion Control 

Corrosion is the deterioration of a substance by chemical action. Lead, cadmium, zinc, 

copper and iron might be found in water when metals in water distribution systems corrode. 

Drinking water contaminated with certain metals (such as lead and cadmium) can harm 

human health. 

Corrosion also reduces the useful life of water distribution systems and can promote the 

growth of microorganisms, resulting in disagreeable tastes, odors, slimes and further 

corrosion. Because it is widespread and highly toxic, lead is the corrosion product of greatest 

concern. The EPA has banned the use of lead solders, fluxes and pipes in the installation or 

repair of any public water system. In the past, solder used in plumbing has been 50% tin and 

50% lead. Using lead-free solders, such as silver-tin and antimony-tin is a key factor in lead 

corrosion control. 

The highest level of lead in consumers’ tap water will be found in water that has been 

standing in the pipes after periods of nonuse (overnight or longer). This is because standing 

water tends to leach lead or copper out of the metals in the distribution system more readily 

than does moving water. Therefore, the simplest short-term or immediate measure that can 

be taken to reduce exposure to lead in drinking water is to let the water run for two to three 

minutes before each use. Also, drinking water should not be taken from the hot water tap, as 

hot water tends to leach lead more readily than cold. 

Long-term measures for addressing lead and other corrosion by-products include pH and 

alkalinity adjustment; corrosion inhibitors; coatings and linings; and Cathodic protection, all 

discussed below. 

Cathodic Protection 

Cathodic protection protects steel from corrosion which is the natural electrochemical 

process that results in the deterioration of a material because of its reaction with its 

environment. 

Metallic structures, components, and equipment exposed to aqueous environments, soil, or 

seawater can be subject to corrosive attack and accelerated deterioration. Therefore, it is 

often necessary to utilize either impressed current or sacrificial anode Cathodic protection 

(CP) in combination with coatings as a means of suppressing the natural degradation 

phenomenon to provide a long and useful service life. However, if proper considerations are 

not given, problems can arise which can produce unexpected, premature failure. 

There are two types of Cathodic protection: 

Ø Sacrificial Anodes (Galvanic Systems) 

Ù Impressed (Induced) Current Systems 

How Does Cathodic Protection Work? 

Sacrificial anodes are pieces of metal more electrically active than the steel piping system. 

Because these anodes are more active, the corrosive current will exit from them rather than 

the piping system. Thus, the system is protected while the attached anode is “sacrificed.” 

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Sacrificial anodes can be attached to the existing piping system or coated steel for a preengineered 

cathodic protection system. An asphalt coating is not considered a suitable 

dielectric coating. Depleted anodes must be replaced for continued Cathodic protection of 

the system. 

Impressed or Induced Current Systems 

An impressed current cathodic protection system consists of anodes, cathodes, a rectifier 

and the soil. The rectifier converts the alternating current to direct current. The direct current 

is then sent through an insulated copper wire to anodes that are buried in the soil near the 

piping system. Typical anode materials are ceramic, high silicon cast iron, or graphite. 

Ceramic anodes are not consumed, whereas high silicon cast iron and graphite anodes 

partially dissolve each year and must be replaced over time. The direct current then flows 

from the anode through the soil to the piping system, which acts as the cathode, and back to 

the rectifier through another insulated copper wire. 

As a result of the electrochemical properties of the impressed current cathodic protection 

system, corrosion takes place only at the anodes and not at the piping system. Depleted 

anodes must be replaced for continued cathodic protection of the piping system. 

Sacrificial Anode System 

In this system, a metal or alloy reacting more vigorously than the corroding specimen acts as 

an anode and the corroding structure as a whole is rendered Cathodic. These anodes are 

made of materials such as magnesium, aluminum or zinc, which are anodic with respect to 

the protected structure. The sacrificial anodes are connected directly to the structure. 

Advantages 

1. Needs no external power source. 

2. Does not involve maintenance work 

3. If carefully designed, it can render protection for anticipated period. 

4. Installation is simple. 

5. Does not involve expensive accessories like rectifier unit, etc., 

6. Economical for small structures 

Disadvantages 

1. The driving voltage is small and therefore the anodes have to be fitted close to the 

structure or on the structure, thereby increasing the weight or load on the structure. 

2. The anodes have to be distributed all over the structure (as throwing power is lower) and 

therefore have design limitations in certain applications. 

3. Once designed and installed, protection current cannot be altered or increased as may be 

needed in case of cathode area extension (unprotected) or foreign structure interference 

(physical contact). 

Impressed Current System 

The impressed current anode system, on the other hand, has several advantages over the 

sacrificial anode systems. In this system the protection current is "Forced" through the 

environment to the structure (cathode) by means of an external D.C. source. Obviously we 

need some material to function as anodes. It can be high silicon chromium cast iron anodes, 

graphite anodes, or lead-silver alloy anodes. 

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Advantages 

1. Since the driving voltage is large, this system offers freedom of installation design and 

location 

2. Fewer anodes can protect a large structure 

3. Variations in protection current requirements can be adjusted to some extent (to be 

incorporated at design stage) 

Disadvantages 

1. Shut down of D.C. supply for a long time allows structure to corrode again. 

2. Reversal of anode cathode connection at D.C. source will be harmful as structure will 

dissolve anodic 

3. Needs trained staff for maintenance of units and for monitoring 

4. Initial investments are higher and can pay off only in long run and economic only for large 

structures 

5. Power cost must be incorporated in all economic consideration. 

6. Possibility of overprotection should be avoided as it will affect the life of the paint. 

7. Any foreign structure coming within this field will cause an interference problem. 

Raw Water Intake 

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Alkalinity and pH Adjustment 

Adjusting pH and alkalinity is the most common corrosion control method because it is 

simple and inexpensive. pH is a measure of the concentration of hydrogen ions present in 

water; alkalinity is a measure of water’s ability to neutralize acids. 

Generally, water pH less than 6.5 is associated with uniform corrosion, while pH between 6.5 

and 8.0 can be associated with pitting corrosion. Some studies have suggested that systems 

using only pH to control corrosion should maintain a pH of at least 9.0 to reduce the 

availability of hydrogen ions as electron receptors. However, pH is not the only factor in the 

corrosion equation; carbonate and alkalinity levels affect corrosion as well. 

Generally, an increase in pH and alkalinity can decrease corrosion rates and help form a 

protective layer of scale on corrodible pipe material. Chemicals commonly used for pH and 

alkalinity adjustment are 

hydrated lime (CaOH2 or 

calcium hydroxide), caustic 

soda (NaOH or sodium 

hydroxide), soda ash (Na2CO3 

or sodium carbonate), and 

sodium bicarbonate (NaHCO3, 

essentially baking soda). 

Care must be taken, however, 

to maintain pH at a level that 

will control corrosion but not 

conflict with optimum pH levels 

for disinfection and control of 

disinfection by-products. 

Corrosion Inhibitors 

Inhibitors reduce corrosion by 

forming protective coatings on 

pipes. The most common 

corrosion inhibitors are inorganic phosphates, sodium silicates and mixtures of phosphates 

and silicates. These chemicals have proven successful in reducing corrosion in many water 

systems. 

The phosphates used as corrosion inhibitors include polyphosphates, orthophosphates, 

glassy phosphates and bimetallic phosphates. In some cases, zinc is added in conjunction 

with orthophosphates or polyphosphates. 

Glassy phosphates, such as sodium hexametaphosphate, effectively reduce iron corrosion 

at dosages of 20 to 40 mg/l. Glassy phosphate has an appearance of broken glass and can 

cut the operator. Sodium silicates have been used for over 50 years to inhibit corrosion. The 

effectiveness depends on the water pH and carbonate concentration. 

Sodium silicates are particularly effective for systems with high water velocities, low 

hardness, low alkalinity and a pH of less than 8.4. Typical coating maintenance doses range 

from 2 to 12 mg/1. They offer advantages in hot water systems because of their chemical 

stability. For this reason, they are often used in the boilers of steam heating systems. 

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Common water sample bottles for distribution systems. 

Radiochems, VOCs, (Volatile Organic Compounds), TTHMs, Total Trihalomethanes), Nitrate, 

Nitrite. 

Most of these sample bottles will come with the preservative already inside the bottle. 

Some bottles will come with a separate preservative (acid) for the field preservation. 

Slowly add the acid or other preservative to the water sample; not water to the acid or 

preservative. 

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Surface Water 

Some of the water will be immediately impounded in lakes and reservoirs, and some will 

collect as runoff to form streams and rivers that will then flow into the ocean. Water is known 

as the universal solvent because most substances that come in contact with it will dissolve. 

What’s the difference between lakes and reservoirs? Reservoirs are lakes with man-made 

dams. Surface water is usually contaminated and unsafe to drink. Depending on the region, 

some lakes and rivers receive discharge from sewer facilities or defective septic tanks. 

Runoff could produce mud, leaves, decayed vegetation, and human and animal refuse. The 

discharge from industry could increase volatile organic compounds. Some lakes and 

reservoirs may experience seasonal turnover. Changes in the dissolved oxygen, algae, 

temperature, suspended solids, turbidity, and carbon dioxide will change because of 

biological activities. 

Quality of Water 

If you classified water by its 

characteristics and could see how water 

changes as it passes on the surface and 

below the ground it would be in these four 

categories: 

Physical characteristics such as taste, 

odor, temperature, and turbidity; this is 

how the consumer judges how well the 

provider is treating the water. 

Chemical characteristics are the 

elements found that are considered alkali, 

metals, and non-metals such as fluoride, 

sulfides or acids. The consumer relates it 

to scaling of faucets or staining. 

Biological characteristics are the presence of living or dead organisms. This will also 

interact with the chemical composition of the water. The consumer will become sick or 

complain about hydrogen sulfide odors--the rotten egg smell. 

Radiological characteristics are the result of water coming in contact with radioactive 

materials. This could be associated with atomic energy. 

Managing Water Quality at the Source 

Depending on the region, source water may have several restrictions of use as part of a 

Water Shed Management Plan. In some areas, it may be restricted from recreational use, 

discharge or runoff from agriculture, or industrial and wastewater discharge. Another aspect 

of quality control is aquatic plants. The ecological balance in lakes and reservoirs plays a 

natural part in purifying and sustaining the life of the lake. For example, algae and rooted 

aquatic plants are essential in the food chain of fish and birds. Algae growth is the result of 

photosynthesis. Algae growth is supplied by the energy of the sun. As algae absorbs this 

energy, it converts carbon dioxide to oxygen. 

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This creates aerobic conditions that supply fish with oxygen. Without sun light, the algae 

would consume oxygen and release carbon dioxide. The lack of dissolved oxygen in water is 

known as anaerobic conditions. Certain vegetation removes the excess nutrients that would 

promote the growth of algae. Too much algae will imbalance the lake and kill fish. 

Most treatment plant upsets such as taste and odor, color, and filter clogging is due to algae. 

The type of algae determines the problem it will cause, for instance slime, corrosion, color, 

and toxicity. Algae have been controlled by using chemicals such as copper sulfate. 

Depending on federal regulations and the amount of copper found natural in water, operators 

have used potassium permanganate, powdered activated carbon and chlorine. The pH and 

alkalinity of the water will determine how these chemicals will react. Most systems no longer 

use Chlorine because it reacts with the organics in the water to form Trihalomethanes. 

Examples of different types of 

chemical storage tanks found in 

water treatment facilities. 

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Review Statements 

Surface Water 

As with Surface water, it is important to remember that activities many miles away from 

you may affect the quality of ground water. Your annual drinking report or CCR will tell you 

where your water supplier gets your water. Your water will normally contain chlorine and 

varying amounts of dissolved minerals including calcium, magnesium, sodium, chlorides, 

sulfates and bicarbonates, depending on its source. It is also not uncommon to find traces 

of iron, manganese, copper, aluminum, nitrates, insecticides and herbicides. Although the 

maximum amounts of all these substances as mentioned above, are strictly limited by the 

regulations. These are usually referred to as contaminants 

Surface water is usually contaminated and unsafe to drink. Depending on the region, some 

lakes and rivers receive discharge from sewer facilities or defective septic tanks. 

Runoff could produce mud, leaves, decayed vegetation, and human and animal refuse. 

The discharge from industry could increase volatile organic compounds. 

Some lakes and reservoirs may experience seasonal turnover. 

Changes in the dissolved oxygen, algae, temperature, suspended solids, turbidity, and 

carbon dioxide will change because of biological activities. 

Physical characteristics such as taste, odor, temperature, and turbidity; this is how the 

consumer judges how well the provider is treating the water. Physical characteristics are 

the elements found that are considered alkali, metals, and non-metals such as fluoride, 

sulfides or acids. The consumer relates it to scaling of faucets or staining. 

Biological characteristics are the presence of living or dead organisms. Biological 

characteristics will also interact with the chemical composition of the water. The consumer 

will become sick or complain about hydrogen sulfide odors, the rotten egg smell. 

Radiological characteristics are the result of water coming in contact with radioactive 

materials. This could be associated with atomic energy. 

Most of these substances are of natural origin and are picked up as water passes around 

the water cycle. Some are present due to the treatment processes which are used make 

the water suitable for drinking and cooking. The water will also contain a relatively low 

level of bacteria, which are not generally a risk to health. 

Insecticides and herbicides (sometimes referred to as pesticides) are widely used in 

agriculture, industry, leisure facilities and gardens to control weeds and insect pests and 

may enter the water cycle in many ways. 

Aluminum salts are added during water treatment to remove color and suspended solids. 

Lead does not usually occur naturally in water supplies but is derived from lead distribution 

and domestic pipework and fittings. 

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Water suppliers have removed most of the original lead piping from the mains distribution 

system, many older properties still have lead service pipes and internal lead pipework. 

The pipework (including the service pipe) within the boundary of the property is the 

responsibility of the owner of the property, not the water supplier. 

Hardness 

There are two types of hardness: temporary and permanent. Temporary hardness comes 

out of the water when it's heated and is deposited as scale and fur on kettles, coffee 

makers and taps and appears as a scum or film on tea and coffee. Permanent hardness is 

unaffected by heating. 

Cysts 

Cysts are associated with the reproductive stages of parasitic micro-organisms 

(protozoans) which can cause acute diarrhea type illnesses; they come from farm animals, 

wild animals and people. Cysts are very resistant to normal disinfection processes but can 

be removed by advanced filtration processes installed in water treatment works. Cysts are 

rarely present in the public water supply. 

Particles and rust come from the gradual breakdown of the lining of concrete or iron mains 

water pipes or from sediment which has accumulated over the years and is disturbed in 

some way. 

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Water Production Section 

Groundwater and Wells 

A well can be easily contaminated if it is not properly constructed or if toxic materials are 

released into the well. Toxic material spilled or dumped near a well can leach into the aquifer 

and contaminate the groundwater drawn from that well. Contaminated wells used for drinking 

water are especially dangerous. Wells can be tested to see what chemicals may be in the well 

and if they are present in dangerous quantities. 

Groundwater is withdrawn from wells to provide water for everything from drinking water for 

the home and business to water for irrigating crops. When water is pumped from the ground, 

the dynamics of groundwater flow change in response to this withdrawal. Groundwater flows 

slowly through water-bearing formations (aquifers) at different rates. In some places, where 

groundwater has dissolved limestone to form caverns and large openings, its rate of flow can 

be relatively fast, but this is exceptional. 

Groundwater production well with a mineral oil sealed vertical turbine pump. 

Sometimes, this mineral oil will get into the distribution system. 

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Groundwater Resource 

Many terms are used to describe the nature and extent of the groundwater resource. The level 

below which all the spaces are filled with water is called the water table. Above the water table lies 

the unsaturated zone. Here the spaces in the rock and soil contain both air and water. Water in 

this zone is called soil moisture. The entire region below the water table is called the saturated 

zone and water in this saturated zone is called groundwater. 

Fractured aquifers are rocks in which the groundwater moves through cracks, joints or fractures 

in otherwise solid rock. Examples of fractured aquifers include granite and basalt. Limestones are 

often fractured aquifers, but here the cracks and fractures may be enlarged by solution, forming 

large channels or even caverns. Limestone terrain where solution has been very active is termed 

karst. Porous media such as sandstone may become so highly cemented or recrystalized that all 

of the original space is filled. In this case, the rock is no longer a porous medium. However, if it 

contains cracks it can still act as a fractured aquifer. Most of the aquifers of importance to us are 

unconsolidated porous media such as sand and gravel. Some very porous materials are not 

permeable. Clay, for instance, has many spaces between its grains, but the spaces are not large 

enough to permit free movement of water. 

Groundwater usually flows downhill with the slope of the water table. Like surface water, 

groundwater flows toward, and eventually drains into, streams, rivers, lakes and the oceans. 

Groundwater flow in the aquifers underlying surface drainage basins, however, does not always 

mirror the flow of water on the surface. Therefore, groundwater may move in different directions 

below the ground than the water flowing on the surface. 

Unconfined aquifers are those that are bounded by the water table. Some aquifers, however, lie 

beneath layers of impermeable materials. These are called confined aquifers, or sometimes 

artesian aquifers. A well in such an aquifer is called an artesian well. The water in these wells 

rises higher than the top of the aquifer because of confining pressure. If the water level rises above 

the ground surface, a flowing artesian well occurs. The piezometric surface is the level to which 

the water in an artesian aquifer will rise. 

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Water Sources 

Before we discuss the types of treatment it is easier to first understand how the source of water 

arrives. 

Water Cycle Terms - Good information for your Assignment. 

� Precipitation: The process by which atmospheric moisture falls onto the land or water surface 

as rain, snow, hail, or other forms of moisture. 

� Infiltration: The gradual flow or movement of water into and through the pores of the soil. 

� Evaporation: The process by which the water or other liquids become a gas. 

� Condensation: The collection of the evaporated water in the atmosphere. 

� Runoff: Water that drains from a saturated or impermeable surface into stream channels or 

other surface water areas. Most lakes and rivers are formed this way. 

� Transpiration: Moisture that will come from plants as a byproduct of photosynthesis. 

Once the precipitation begins, water is no longer in its purest form. Water will be collected as 

surface supplies or circulate to form in the ground. As it becomes rain or snow it may be polluted 

with organisms, organic compounds, and inorganic compounds. Because of this, we must treat the 

water for human consumption. 

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Source Water Quality 

Groundwater 

Groundwater contributes most of all of the water that is derived from wells or springs. It occurs in 

the natural open spaces (i.e., fractures or pore spaces between grains) in sediments and rocks 

below the surface. Groundwater is distributed fairly evenly throughout the crust of the earth, but it 

is not readily accessible or extractable everywhere. More than 90 percent of the world's total 

supply of drinkable water is groundwater. 

Groundwater originates as precipitation that sinks into the ground. Some of this water percolates 

down to the water table (shallowest surface of the groundwater) and recharges the aquifer. For 

shallow wells (i.e., less than 50-75 feet) the recharge area is often the immediate vicinity around 

the well or "wellhead." Some wells are recharged in areas that may be a great distance from the 

well itself. If the downward percolating precipitation encounters any source of contamination, at 

the surface or below it, the water may dissolve some of that contaminant and carry it to the aquifer. 

Groundwater moves from areas where the water table is high to where the water table is low. 

Consequently, a contaminant may enter the aquifer some distance upgradient from you and still 

move towards your well. When a well is pumping, it lowers the water table in the immediate vicinity 

of the well, increasing the tendency for water to move towards the well. Contaminants can be 

lumped into three categories: microorganisms (bacteria, viruses, Giardia, etc.), inorganic chemicals 

(nitrate, arsenic, metals, etc.) and organic chemicals (solvents, fuels, pesticides, etc.). 

Although it is common practice to associate contamination with highly visible features such as 

landfills, gas stations, industry or agriculture, potential contaminants are widespread and often 

come from common everyday activities as well, such as septic systems, lawn and garden 

chemicals, pesticides applied to highway right-of-ways, stormwater runoff, auto repair shops, 

beauty shops, dry cleaners, medical institutions, photo processing labs, etc. Importantly, it takes 

only a very small amount of some chemicals in drinking water to raise health concerns. For 

example, one gallon of pure trichloroethylene, a common solvent, will contaminate approximately 

292 million gallons of water. 

Wellhead Protection 

Wellhead protection refers to programs designed to maintain the quality of groundwater used as 

public drinking water sources by managing the land uses around the wellfield. The theory is that 

management of land use around the well, and over water moving (underground) toward the well, 

will help to minimize damage to subsurface water supplies by spills or improper use of chemicals. 

The concept usually includes several stages. 

Wellhead Protection Sequence 

A) Build a community-wide planning team. 

B) Delineate geologically the protection zone. 

C) Perform a contaminant use inventory. 

D) Create a management plan for the protection zone. 

E) Plan for the future. 

Water Rights 

Appropriative: Acquired water rights for exclusive use. 

Prescriptive: Rights based upon legal prescription or long use or custom. 

Riparian: Water rights because property is adjacent to a river or surface water. 

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Contaminated Wells 

Contaminated wells used for drinking water are especially dangerous. Wells can be tested to see 

what chemicals may be in the well and if they are present in dangerous quantities. 

Groundwater is withdrawn from wells to provide water for everything from drinking water for the 

home and business to water to irrigate crops to industrial processing water. When water is pumped 

from the ground, the dynamics of groundwater flow change in response to this withdrawal. 

Groundwater flows slowly through water-bearing formations (aquifers) at different rates. In some 

places, where groundwater has dissolved limestone to form caverns and large openings, its rate of 

flow can be relatively fast but this is exceptional. 

Well with a mineral oil sealed vertical turbine pump. 

Aquifer 

Many terms are used to describe the nature and extent of the groundwater resource. The level 

below which all the spaces are filled with water is called the water table. Above the water table lies 

the unsaturated zone. Here the spaces in the rock and soil contain both air and water. Water in this 

zone is called soil moisture. The entire region below the water table is called the saturated zone 

and water in this saturated zone is called groundwater. 

Fractured aquifers are cracks, joints, or fractures in solid rock, through which groundwater moves. 

Examples of fractured aquifers include granite and basalt. Limestones are often fractured aquifers, 

but here the cracks and fractures may be enlarged by solution, forming large channels or even 

caverns. Limestone terrain where solution has been very active is termed karst. 

Porous media such as sandstone may become so highly cemented or recrystalized that all of the 

original space is filled. In this case, the rock is no longer a porous medium. However, if it contains 

cracks it can still act as a fractured aquifer. Most of the aquifers of importance to us are 

unconsolidated porous media such as sand and gravel. Some very porous materials are not 

permeable. Clay, for instance, has many spaces between its grains, but the spaces are not large 

enough to permit free movement of water. 

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Groundwater usually flows downhill with the slope of the water table. Like surface water, 

groundwater flows toward, and eventually drains into, streams, rivers, lakes and the oceans. 

Groundwater flow in the aquifers underlying springs or surface drainage basins, however, does not 

always mirror the flow of water on the surface. 

Therefore, groundwater may move in different directions below the ground than the water flowing 

on the surface. 

Vertical Turbine Well 

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Unconfined aquifers are those that are bounded by the water table. Some aquifers, however, lie 

beneath layers of impermeable materials. These are called confined aquifers, or some-times 

artesian aquifers. A well in such an aquifer is called an artesian well. The water in these wells rises 

higher than the top of the aquifer because of confining pressure. If the water level rises above the 

ground surface a flowing artesian well occurs. 

The piezometric surface is the level to which the water in an artesian aquifer will rise. 

Cone of Depression 

When pumping begins, water begins to flow towards the well in contrast to the natural direction of 

groundwater movement. The water level in the well falls below the water table in the surrounding 

aquifer. 

As a result, water begins to move from the aquifer into the well. As pumping continues, the water 

level in the well continues to increase until the rate of flow into the well equals the rate of 

withdrawal from pumping. The movement of water from an aquifer into a well results in the 

formation of a cone of depression. The cone of depression describes a three-dimensional inverted 

cone surrounding the well that represents the volume of water removed as a result of pumping. 

Drawdown is the vertical drop in the height between the water level in the well prior to pumping and 

the water level in the well during pumping. 

When a well is installed in an unconfined aquifer, water moves from the aquifer into the well 

through small holes or slits in the well casing or, in some types of wells, through the open bottom of 

the well. The level of the water in the well is the same as the water level in the aquifer. 

Groundwater continues to flow through and around the well in one direction in response to gravity. 

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Groundwater Section 

Aquifer Description 

Half of all Americans and more than 95 percent of rural Americans get their household water 

supplies from underground sources of water, or ground water. Ground water also is used for 

about half of the nation's agricultural irrigation and nearly one-third of the industrial water 

needs. This makes ground water a vitally important national resource. 

Over the last 10 years, however, public attention has been drawn to incidents of groundwater 

contamination. This has led to the development of ground-water protection programs 

at federal, state, and local levels. Because ground-water supplies and conditions vary from 

one area to another, the responsibility for protecting a community's ground-water supplies 

rests substantially with the local community. 

If your community relies on ground water to supply any portion of its fresh water needs, you, 

the citizen, will be directly affected by the success or failure of a ground-water protection 

program. Equally important, you, the citizen, can directly affect the success or failure of your 

community's ground-water protection efforts. 

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This guide is intended to help you take an active and positive role in protecting your 

community's ground-water supplies. It will introduce you to the natural cycle that supplies the 

earth with ground water, briefly explain how ground water can become contaminated, 

examine ways to protect our vulnerable ground-water supplies, and, most important of all, 

describe the roles you and your community can play in protecting valuable ground-water 

supplies. 

Groundwater Transducer (pH, Temp. chemical detection and D.O.) depth probe. 

These tools are used to find the depth and pH of well water. 

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Groundwater Explained 

Many people have never heard of ground water. That's not really so surprising since it isn't readily 

visible -- ground water can be considered one of our "hidden" resources. 

What Is Groundwater and Where Does It Come From? 

Actually ground water occurs as part of what can be called the oldest recycling program - the 

hydrologic cycle. The hydrologic cycle involves the continual movement of water between the earth 

and the atmosphere through evaporation and precipitation. As rain and snow fall to the earth, some of 

the water runs off the surface into lakes, rivers, streams, and the oceans; some evaporates; and some 

is absorbed by plant roots. The rest of the water soaks through the ground's surface and moves 

downward through the unsaturated zone, where the open spaces in rocks and soil are filled with a 

mixture of air and water, until it reaches the water table. The water table is the top of the saturated 

zone, or the area in which all interconnected spaces in rocks and soil are filled with water. The water in 

the saturated zone is called ground water. In areas where the water table occurs at the ground's 

surface, the ground water discharges into marshes, lakes, springs, or streams and evaporates into the 

atmosphere to form clouds, eventually falling back to earth again as rain or snow - thus beginning the 

cycle all over again. 

Where Is Ground Water Stored? 

Ground water is stored under many types of geologic conditions. Areas where ground water exists in 

sufficient quantities to supply wells or springs are called aquifers, a term that literally means "water 

bearer." Aquifers store water in the spaces between particles of sand, gravel, soil, and rock as well as 

cracks, pores, and channels in relatively solid rocks. An aquifer's storage capacity is controlled largely 

by its porosity, or the relative amount of open space present to hold water. Its ability to transmit water, 

or permeability, is based in part on the size of these spaces and the extent to which they are 

connected. Basically, there are two kinds of aquifers: confined and unconfined. If the aquifer is 

sandwiched between layers of relatively impermeable materials (e.g., clay), it is called a confined 

aquifer. Confined aquifers are frequently found at greater depths than unconfined aquifers. In contrast, 

unconfined aquifers are not sandwiched between these layers of relatively impermeable materials, and 

their upper boundaries are generally closer to the surface of the land. 

Does Ground Water Move? 

Ground water can move sideways as well as up or down. This movement is in response to gravity, 

differences in elevation, and differences in pressure. The movement is usually quite slow, frequently 

as little as a few feet per year, although it can move as much as several feet per day in more 

permeable zones. Ground water can move even more rapidly in karst aquifers, which are areas in 

water soluble limestone and similar rocks where fractures or cracks have been widened by the action 

of the ground water to form sinkholes, tunnels, or even caves. 

How Is Ground Water Used? 

According to the U.S. Geological Survey, ground-water use increased from about 35 billion gallons a 

day in 1950 to about 87 billion gallons a day in 1980. Approximately one-half of all fresh water used in 

the nation comes from ground water. Whether it arrives via a public water supply system or directly 

from a private well, ground water ultimately provides approximately 35 percent of the drinking water 

supply for urban areas and 95 percent of the supply for rural areas, quenching the thirst and meeting 

other household needs of more than 117 million people in this nation. 

Overall, more than one-third of the water used for agricultural purposes is drawn from ground water; 

Arkansas, Nebraska, Colorado, and Kansas use more than 90 percent of their ground-water 

withdrawals for agricultural activities. In addition, approximately 30 percent of all ground water is used 

for industrial purposes. Groundwater use varies among the states, with some states, such as Hawaii, 

Mississippi, Florida, Idaho, and New Mexico, relying on ground water to supply considerably more 

than three-fourths of their household water needs and other states, such as Colorado and Rhode 

Island, supplying less than one-quarter of their water needs with ground water. 

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Ground-Water Quality 

Until the 1970s, ground water was believed to be naturally protected from contamination. The layers of 

soil and particles of sand, gravel, crushed rocks, and larger rocks were thought to act as filters, 

trapping contaminants before they could reach the ground water. Since then, however, every state in 

the nation has reported cases of contaminated ground water, with some instances receiving 

widespread publicity. We now know that some contaminants can pass through all of these filtering 

layers into the saturated zone to contaminate ground water. 

Between 1971 and 1985, 245 ground-water related disease outbreaks, with 52,181 associated 

illnesses, were reported. Most of these diseases were short-term digestive disorders. About 10 

percent of all ground-water public water supply systems are in violation of drinking water standards for 

biological contamination. In addition, approximately 74 pesticides, a number of which are known 

carcinogens, have been detected in the ground water of 38 states. Although various estimates have 

been made about the extent of ground-water contamination, these estimates are difficult to verify given 

the nature of the resource and the difficulty of monitoring its quality. 

How Does Ground Water Become Contaminated? 

Ground-water contamination can originate on the surface of the ground, in the ground above the water 

table, or in the ground below the water table. Table I shows the types of activities that can cause 

ground-water contamination at each level. Where a contaminant originates is a factor that can affect 

its actual impact on ground-water quality. For example, if a contaminant is spilled on the surface of the 

ground or injected into the ground above the water table, it may have to move through numerous 

layers of soil and other underlying materials before it reaches the ground water. As the contaminant 

moves through these layers, a number of processes are in operation (e.g., filtration, dilution, oxidation, 

biological decay) that can lessen the eventual impact of the substance once it finally reaches the 

ground water. The effectiveness of these processes also is affected by both the distance between the 

ground water and where the contaminant is introduced and the amount of time it takes the substance 

to reach the ground water. If the contaminant is introduced directly into the area below the water table, 

the primary process that can affect the impact of the contaminant is dilution by the surrounding ground 

water. 

GROUND 

SURFACE 

ABOVE 

WATER 

TABLE 

BELOW 

WATER 

TABLE 

Infiltration of polluted surface water 

Land disposal of wastes 

Stockpiles 

Dumps 

Sewage sludge disposal 

Septic tanks, cesspools, & privies 

Holding ponds & lagoons 

Sanitary landfills 

Waste disposal in excavations 

Underground storage tank leaks 

Waste disposal in wells 

Drainage wells and canals 

Underground storage 

Mines 

De-icing salt use & storage 

Animal feedlots 

Fertilizers & pesticides 

Accidental spills 

Airborne source particulates 

Underground pipeline leaks 

Artificial recharge 

Sumps and dry wells 

Graveyards 

Exploratory wells 

Abandoned wells 

Water-supply wells 

Ground-water withdrawal 

TABLE 1. Activities That Can Cause Ground-Water Contamination 

In comparison with rivers or streams, ground water tends to move very slowly and with very little 

turbulence. Therefore, once the contaminant reaches the ground water, little dilution or dispersion 

normally occurs. Instead, the contaminant forms a concentrated plume that can flow along the same 

path as the ground water. Among the factors that determine the size, form, and rate of movement of 

the contaminant plume are the amount and type of contaminant and the speed of ground-water 

movement. Because ground water is hidden from view, contamination can go undetected for years 

until the supply is tapped for use. 

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What Kinds of Substances Can Contaminate Groundwater, and Where Do They Come From? 

Substances that can contaminate ground water can be divided into two basic categories: substances 

that occur naturally and substances produced or introduced by man's activities. Substances that occur 

naturally include minerals such as iron, calcium, and selenium. Substances resulting from man's 

activities include synthetic organic chemicals and hydrocarbons (e.g., solvents, pesticides, petroleum 

products); landfill leachates (liquids that have dripped through the landfill and carry dissolved 

substances from the waste materials), containing such substances as heavy metals and organic 

decomposition products; salt; bacteria; and viruses. A significant number of today's ground-water 

contamination problems stem from man's activities and can be introduced into ground water from a 

variety of sources. 

Septic Tanks, Cesspools, and Privies 

A major cause of ground-water contamination in many areas of the United States is effluent, or 

outflow, from septic tanks, cesspools, and privies. Approximately one fourth of all homes in the United 

States rely on septic systems to dispose of their human wastes. If these systems are improperly sited, 

designed, constructed, or maintained, they can allow contamination of the ground water by bacteria, 

nitrates, viruses, synthetic detergents, household chemicals, and chlorides. Although each system can 

make an insignificant contribution to ground-water contamination, the sheer number of such systems 

and their widespread use in every area that does not have a public sewage treatment system makes 

them serious contamination sources. 

Surface Impoundments 

Another potentially significant source of ground-water contamination is the more than 180,000 surface 

impoundments (e.g., ponds, lagoons) used by municipalities, industries, and businesses to store, treat, 

and dispose of a variety of liquid wastes and wastewater. Although these impoundments are 

supposed to be sealed with compacted clay soils or plastic liners, leaks can and do develop. 

Agricultural Activities 

Agricultural activities also can make significant contributions to ground-water contamination with the 

millions of tons of fertilizers and pesticides spread on the ground and from the storage and disposal of 

livestock wastes. Homeowners, too, can contribute to this type of ground-water pollution with the 

chemicals they apply to their lawns, rosebushes, tomato plants, and other garden plants. 

Landfills 

There are approximately 500 hazardous waste land disposal facilities and more than 16,000 municipal 

and other landfills nationwide. To protect ground water, these facilities are now required to be 

constructed with clay or synthetic liners and leachate collection systems. Unfortunately, these 

requirements are comparatively recent, and thousands of landfills were built, operated, and 

abandoned in the past without such safeguards. A number of these sites have caused serious groundwater 

contamination problems and are now being cleaned up by their owners, operators, or users; 

state governments; or the federal government under the Superfund program (see p. 8). In addition, a 

lack of information about the location of many of these sites makes it difficult, if not impossible, to 

determine how many others may now be contaminating ground water. 

Underground Storage Tanks 

Between five and six million underground storage tanks are used to store a variety of materials, 

including gasoline, fuel oil, and numerous chemicals. The average life span of these tanks is 18 years, 

and over time, exposure to the elements causes them to corrode. Now, hundreds of thousands of 

these tanks are estimated to be leaking, and many are contaminating ground water. Replacement 

costs for these tanks are estimated at $1 per gallon of storage capacity; a cleanup operation can cost 

considerably more. 

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Abandoned Wells 

Wells can be another source of ground-water contamination. In the years before there were 

community water supply systems, most people relied on wells to provide their drinking water. In rural 

areas this can still be the case. If a well is abandoned without being properly sealed, however, it can 

act as a direct channel for contaminants to reach ground water. 

Accidents and Illegal Dumping 

Accidents also can result in ground-water contamination. A large volume of toxic materials is 

transported throughout the country by truck, train, and airplane. 

Every day accidental chemical or petroleum product spills occur that, if not handled properly, can 

result in ground-water contamination. Frequently, the automatic reaction of the first people at the 

scene of an accident involving a spill will be to flush the area with water to dilute the chemical. This 

just washes the chemical into the soil around the accident site, allowing it to work its way down to the 

ground water. In addition, there are numerous instances of ground-water contamination caused by the 

illegal dumping of hazardous or other potentially harmful wastes. 

Highway De-icing 

A similar flushing mechanism also applies to the salt that is used to de-ice roads and highways 

throughout the country every winter. More than 11 million tons of salt are applied to roads in the United 

States annually. As ice and snow melt or rain subsequently falls, the salt is washed into the 

surrounding soil where it can work its way down to the ground water. Salt also can find its way into 

ground water from improperly protected storage stockpiles. 

What Can Be Done After Contamination Has Occurred? 

Unlike rivers, lakes, and streams that are readily visible and whose contamination frequently can be 

seen with the naked eye, ground water itself is hidden from view. Its contamination occurs gradually 

and generally is not detected until the problem has already become extensive. This makes cleaning up 

contamination a complicated, costly, and sometimes impossible process. 

In general, a community whose ground-water supply has been contaminated has five options: 

* Contain the contaminants to prevent their migration from their source. 

* Withdraw the pollutants from the aquifer. 

* Treat the ground water where it is withdrawn or at its point of use. 

* Rehabilitate the aquifer by either immobilizing or detoxifying the contaminants while they are 

still in the aquifer. 

* Abandon the use of the aquifer and find alternative sources of water 

Which option is chosen by the community is determined by a number of factors, including the nature 

and extensiveness of the contamination, whether specific actions are required by statute, the geologic 

conditions, and the funds available for the purpose. All of these options are costly. For example, a 

community in Massachusetts chose a treatment option when the wells supplying its public water 

system were contaminated by more than 2,000 gallons of gasoline that had leaked into the ground 

from an underground storage tank less than 600 feet from one of the wells. 

The town temporarily provided alternative water supplies for its residents and then began a cleanup 

process that included pumping out and treating the contaminated water and then recharging the 

aquifer with the treated water. The cleanup effort alone cost more than $3 million. Because of the high 

costs and technical difficulties involved in the various containment and treatment methods, many 

communities will choose to abandon the use of the aquifer when facing contamination of their groundwater 

supplies. This requires the community to either find other water supplies, drill new wells farther 

away from the contaminated area of the aquifer, deepen existing wells, or drill new wells in another 

aquifer if one is located nearby. As Atlantic City, New Jersey, found, these options also can be very 

costly for a community. The wells supplying that city's public water system were contaminated by 

leachate from a landfill. The city estimated that development of a new wellfield would cost 

approximately $2 million. 

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Government Ground-Water Protection Activities 

Given the importance of ground water as a source of drinking water for so many communities and 

individuals and the cost and difficulty of cleaning it up, common sense tells us that the best way to 

guarantee continued supplies of clean ground water is to prevent contamination. 

Are There Federal Laws or Programs to Protect Ground Water? 

The U.S. Environmental Protection Agency (EPA) is responsible for federal activities relating to the 

quality of ground water. EPA's ground-water protection activities are authorized by a number of laws, 

including: 

* The Safe Drinking Water Act, which authorizes EPA to set standards for maximum levels of 

contaminants in drinking water, regulate the underground disposal of wastes in deep wells, designate 

areas that rely on a single aquifer for their water supply, and establish a nationwide program to 

encourage the states to develop programs to protect public water supply wells (i.e., wellhead 

protection programs). 

* The Resource Conservation and Recovery Act, which regulates the storage, transportation, 

treatment, and disposal of solid and hazardous wastes to prevent contaminants from leaching into 

ground water from municipal landfills, underground storage tanks, surface impoundments, and 

hazardous waste disposal facilities. 

* The Comprehensive Environmental Response, Compensation, and Liability Act (Superfund), 

which authorizes the government to clean up contamination caused by chemical spills or hazardous 

waste sites that could (or already do) pose threats to the environment, and whose 1986 amendments 

include provisions authorizing citizens to sue violators of the law and establishing "community right-toknow" 

programs (Title III). 

* The Federal Insecticide, Fungicide, and Rodenticide Act, which authorizes EPA to control the 

availability of pesticides that have the ability to leach into ground water. 

* The Toxic Substances Control Act which authorizes EPA to control the manufacture, use, 

storage, distribution, or disposal of toxic chemicals that have the potential to leach into ground water. 

* The Clean Water Act, which authorizes EPA to make grants to the states for the development 

of ground-water protection strategies and authorizes a number of programs to prevent water pollution 

from a variety of potential sources. 

The federal laws tend to focus on controlling potential sources of ground-water contamination on a 

national basis. Where federal laws have provided for general ground-water protection activities such 

as wellhead protection programs or development of state ground-water protection strategies, the 

actual implementation of these programs must be by the states in cooperation with local governments. 

A major reason for this emphasis on local action is that protection of ground water generally involves 

making very specific decisions about how land is used. Local governments frequently exercise a 

variety of land-use controls under state laws. 

Do the States Have Laws or Programs to Protect Ground Water? 

According to a study conducted for EPA in 1988, most of the states have passed some type of groundwater 

protection legislation and developed some kind of ground-water policies. State ground-water 

legislation can be divided into the following subject categories: 

* Statewide strategies - Requiring the development of a comprehensive plan to protect the 

state's ground-water resources from contamination. 

* Ground-water classification - Identifying and categorizing ground-water sources by how they 

are used to determine how much protection is needed to continue that type of use. 

* Standard setting - Identifying levels at which an aquifer is considered to be contaminated. 

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* Land-use management - Developing planning and regulatory mechanisms to control activities 

on the land that could contaminate an aquifer. 

* Ground-water funds - Establishing specific financial accounts for use in the protection of 

ground-water quality and the provision of compensation for damages to underground drinking water 

supplies (e.g., reimbursement for ground-water cleanup, provision of alternative drinking water 

supplies). 

* Agricultural chemicals - Regulating the use, sale, labeling, and disposal of pesticides, 

herbicides, and fertilizers. 

* Underground storage tanks - Establishing criteria for the registration, construction, installation, 

monitoring, repair, closure, and financial responsibility associated with tanks used to store hazardous 

wastes or materials. 

* Water-use management - Including ground-water quality protection in the criteria used to 

justify more stringent water allocation measures where excessive ground-water withdrawal could 

cause ground-water contamination. 

Appendix 1 presents a matrix showing the types of ground-water protection legislation enacted by the 

states. In addition to ground-water protection programs states may have developed under their own 

laws, one state ground-water protection program is required by federal law. The 1986 amendments to 

the Safe Drinking Water Act established the wellhead protection program and require each state to 

develop comprehensive programs to protect public water supply wells from contaminants that could be 

harmful to human health. Wellhead protection is simply protection of all or part of the area surrounding 

a well from which the well's ground water is drawn. This is called a wellhead protection area (WHPA). 

The size of the WHPA will vary from site to site depending on a number of factors, including the goals 

of the state's program and the geologic features of the area. 

The law specifies certain minimum components for the wellhead protection programs: 

* The roles and duties of state and local governments and public water suppliers in the 

management of wellhead protection programs must be established. 

* The WHPA for each wellhead must be delineated (i.e., outlined or defined). 

* Contamination sources within each WHPA must be identified. 

* Approaches for protecting the water supply within the WHPAs from the contamination sources 

(e.g., use of source controls, education, training) must be developed. 

* Contingency plans must be developed for use if public water supplies become contaminated. 

* Provisions must be established for proper sitting of new wells to produce maximum water yield 

and reduce the potential for contamination as much as possible. 

* Provisions must be included to ensure public participation in the process. 

For a program to be successful, all levels of government must participate in the wellhead protection 

program. The federal government is responsible for approving state wellhead protection programs and 

for providing technical support to state and local governments. State governments must develop and 

implement wellhead protection programs that meet the requirements of the Safe Drinking Water Act. 

Although the responsibilities of local governments depend on the specific requirements of their state's 

program, these governments often are in the best position (and have the greatest incentive) to ensure 

proper protection of wellhead areas. They have the most to lose if their ground-water becomes 

contaminated. 

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Well Development Section 

Once well construction is complete, the well is developed. The purpose of well development is to 

purge the well and bore of all drilling mud and or fluid, fine grained sediment, and loose aquifer matter. 

The well development process also helps to settle the gravel or filter pack and/or rearrange particles 

within the well and nearby aquifer to allow for the most efficient operation of the well. Not surprisingly, 

the drilling procedure often damages the aquifer around the well. 

Well development can significantly improve a well’s performance by essentially repairing as much of 

this damage as possible by improving the transition from the aquifer to the well. The screened and 

productive portions of the well can be subjected to various development techniques. 

All methods of well development essentially involve the flushing of water back and forth between the 

well and aquifer. 

If you think of the aquifer as one great big natural media filter, the development process to a well is 

much the same as the backwashing process for a water treatment system. So what about hard rock 

wells? Wells constructed in hard rock aquifers are not composed of unconsolidated sediments. Still, 

they can and should be developed because fine cuttings, drilling mud, and clay within the fractures 

and pore spaces near the well can obstruct flow from otherwise productive zones. 

Well development procedures can remove such sediments from hard rock wells also. Several 

common methods of well development include, surge-block, jetting, airlift, and pump surging. 

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Well Surging or Backwashing 

Pump surging (sometimes called Rawhiding) involves the repeated pumping and resting of the well 

for well development purposes. A column of water that is withdrawn through a pump is allowed to 

surge back into the well by turning the pump on and off repeatedly. However, sufficient time for the 

pump motor to stop reverse rotation must be allowed, such that pump damage can be avoided. 

Occasionally, water is pumped to waste until it is clear of sediment before again shutting the pump off. 

This is done to permanently remove the sediments that are being developed by the backwashing 

action. The process continues until sufficient quantities of water produced are consistently clean. 

Surge-blocks, swabs, or plungers are disc shaped devices made to fit tightly within the well. Their 

edges are usually fitted with rubber or leather rings to make a tight seal against the well casing. Pipe 

sections are then attached to the surge-block to lower it into the well, above the well screen, and about 

15 feet below the water level. The assembly is then repeatedly lifted up and down. The up and down 

action of the surge-block creates suction, and compression strokes that force water in and out of the 

well through the screened interval, gravel pack, and aquifer. It works like a plunger in the way that it 

removes small obstructions and sediments from the well. The surge-block is slowly lowered each time 

resistance begins to decrease. 

Once the top of the screen is reached, the assembly may be removed and accumulated sediment 

either bailed or airlifted out of the well. Surging within known problem areas of the screened interval 

may be conducted also. The cycle of swabbing and removing sediment should be continued until 

resistance to the action of the swab or block is significantly lower than at the start of development. 

The development is complete when the amount of sediment removed is both significantly and 

consistently less than when surging began. 

Airlifting (or Air surging) involves the introduction of large short blasts of air within the well that lifts 

the column of water to the surface and then drop it back down again. Continuous airlifting or air 

pumping from the bottom of the well is then used occasionally to lift sediments out of the well. Airlift 

development is most often used following initial pump surging, and is employed to confirm that the well 

is productive, since the injection of air into a plugged well may result in casing or screen failure. 

Air lifting development is most often done with a rotary drilling rig through the drill string. Sometimes 

special air diffusers or jets are used to direct the bursts of air into preferred directions (see jetting). 

Piping is inserted into the well and intermittent blasts of air are introduced as the piping is slowly 

lowered into the well. Sometimes surfactant or drill foam is added to aid in the efficiency of sediment 

removal and cleaning of the well. Air surging development is much the same as drilling the well with air 

rotary; only the well has already been constructed. Specialized air development units are available 

independent of a drilling rig, which may be used as well. The great thing about air rotary drilled wells 

is that they are essentially developed while drilling, particularly in hard rock formations, when greater 

than 100 gallons per minute is being lifted to the surface. The development of a filter pack (if used) in 

such wells is still recommended. 

Jetting is a type of well development technique in which water and/or air is jetted or sprayed 

horizontally into the well screen. This method is especially suited for application in stratified and 

unconsolidated formations. The water or air is forced through nozzles in a specially designed jetting 

tool (or simply drilled pipe and fittings) at high velocities. Normally, air lifting or pumping is used in 

conjunction with jetting methods in order to minimize potential damage to the well bore. Jetting with 

water alone can be so powerful that the sediment, which is supposed to be removed, can be forced 

into the formation causing clogging problems. 

This is why pumping or airlifting while jetting with water is so important. Jetting is normally conducted 

from the bottom of the well screen upwards. 

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Rotary Rig 

A rotary rig is often used to provide the fluid or air with sustained pressure while the tool is slowly 

raised up through the screen. As jetting proceeds, sediment is occasionally removed from the bottom 

of the well bore thru the use of a bailer or airlifting. Several passes should be made over the length of 

screen until sediment generation drops off. Air is normally used for jetting in shallow aquifers (less 

than 300 feet of submergence) due to limited supply pressures. Jetting in PVC constructed wells is not 

recommended since the high velocities of fluid and sediment can erode and possibly cut through the 

plastic well screen. In addition, wells constructed with louvered or slotted screen limit the 

effectiveness of jetting. In these types of wells, surging may be more effective. 

Jetting Nozzle 

that can be → 

attached to 

drill pipe. 

Surge of air developing a Well. 

In the best of situations a combination of methods can be used to ensure the efficient 

development and operation of a well. 

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Selecting an Optimum Pumping Rate 

Before a well can be completed with the necessary pumping equipment, it should be tested for 

capacity and proper operation. When the well was drilled, the driller and geologist kept close watch of 

the amount of water production that had been obtained. The development techniques used can also 

be useful in estimating a wells production rate. However, the driller will normally know what to expect 

based on his experience, and the geologist or hydrologist will also obtain information on other nearby 

wells to bracket the expected production rate. If the well was drilled with air rotary, the airlift at the time 

of drilling also can serve as a baseline to estimate the well’s production rate. Either way, the well is 

normally pump tested following well development. 

A pumping test is normally conducted for at least eight hours in order to estimate a well’s maximum 

production rate. Ideally, a twenty-four hour step test is conducted. A step test is a variable rate 

pumping test, typically conducted for 24 hours at up to six different pumping rates. Typically, the well 

will be pumped at the lower estimated maximum pumping rate for the first four hours. 

The pumping rate is then adjusted upwards in equal amounts every four hours until 24 hours of 

pumping have been completed. The personnel conducting the test keep track of the water levels in 

the well to ensure that the steps are not too large and not too small. 

In the end, the optimum pumping rate is selected following a careful review and comparison of the 

water level data for each rate. The well’s specific capacity (Sc) is then determined. Specific capacity is 

the gallons per minute the well can produce per foot of drawdown. Specific capacities for each of the 

pumping steps are compared. The highest Sc observed is normally associated with the optimum 

pumping rate. That rate should also have resulted in stabilized pumping levels or drawdown. 

Well pumping test being conducted in photograph above. (Notice the portable electric 

generator for powering the pump. The Hydrogeologist is using a depth probe to 

measure the drop in the static water level.) 

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Selection of Pumping Equipment 

The proper selection of pumping equipment for a well is of great importance. The primary 

factors that must be considered before selecting the well pump are: flow rate, line pressure, 

pumping lift (total dynamic head), power requirements (and limitations), and size of piping. 

Each of these components must be considered together when selecting well pumps. 

Pumping Lift and Total Dynamic or Discharge Head 

The most important components in selecting the correct pump for your application are: total 

pumping lift and total dynamic or discharge head. Total dynamic head refers to the total 

equivalent feet of lift that the pump must overcome in order to deliver water to its destination, 

including frictional losses in the delivery system. 

Basic Pump Operating Characteristics 

"Head" is a term commonly used with pumps. Head refers to the height of a vertical column 

of water. Pressure and head are interchangeable concepts in irrigation, because a column of 

water 2.31 feet high is equivalent to 1 pound per square inch (PSI) of pressure. The total 

head of a pump is composed of several types of head that help define the pump's operating 

characteristics. 

Total Dynamic Head 

The total dynamic head of a pump is the sum of the total static head, the pressure head, the 

friction head, and the velocity head. 

The Total Dynamic Head (TDH) is the sum of the total static head, the total friction 

head and the pressure head. 

Total Static Head 

The total static head is the total vertical distance the pump must lift the water. When pumping 

from a well, it would be the distance from the pumping water level in the well to the ground 

surface plus the vertical distance the water is lifted from the ground surface to the discharge 

point. When pumping from an open water surface, it would be the total vertical distance from 

the water surface to the discharge point. 

Pressure Head 

The pressure head at any point where a pressure gauge is located can be converted from 

pounds per square inch (PSI) to feet of head by multiplying by 2.31. For example, 20 PSI is 

equal to 20 times 2.31 or 46.2 feet of head. Most city water systems operate at 50 to 60 PSI, 

which, as illustrated in Table 1, explains why the centers of most city water towers are about 

130 feet above the ground. 

Table 1. Pounds per square inch (PSI) and equivalent head in feet of water. 

PSI Head (feet) 

0 0 

5 11.5 

10 23.1 

15 34.6 

20 46.2 

25 57.7 

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30 69.3 

35 80.8 

40 92.4 

45 104 

50 115 

55 127 

60 138 

65 150 

70 162 

75 173 

80 185 

85 196 

90 208 

95 219 

100 231 

Friction Head 

Friction head is the energy loss or pressure decrease due to friction when water flows 

through pipe networks. The velocity of the water has a significant effect on friction loss. Loss 

of head due to friction occurs when water flows through straight pipe sections, fittings, 

valves, around corners, and where pipes increase or decrease in size. Values for these 

losses can be calculated or obtained from friction loss tables. The friction head for a piping 

system is the sum of all the friction losses. 

Velocity Head 

Velocity head is the energy of the water due to its velocity. This is a very small amount of 

energy and is usually negligible when computing losses in an irrigation system. 

Suction Head 

A pump operating above a water surface is working with a suction head. The suction head 

includes not only the vertical suction lift, but also the friction losses through the pipe, elbows, 

foot valves, and other fittings on the suction side of the pump. There is an allowable limit to 

the suction head on a pump and the net positive suction head (NPSH) of a pump sets that 

limit. 

The theoretical maximum height that water can be lifted using suction is 33 feet. Through 

controlled laboratory tests, manufacturers determine the NPSH curve for their pumps. The 

NPSH curve will increase with increasing flow rate through the pump. At a certain flow rate, 

the NPSH is subtracted from 33 feet to determine the maximum suction head at which that 

pump will operate. For example, if a pump requires a minimum NPSH of 20 feet the pump 

would have a maximum suction head of 13 feet. Due to suction pipeline friction losses, a 

pump rated for a maximum suction head of 13 feet may effectively lift water only 10 feet. To 

minimize the suction pipeline friction losses, the suction pipe should have a larger diameter 

than the discharge pipe. 

Operating a pump with suction lift greater than it was designed for, or under conditions with 

excessive vacuum at some point in the impeller, may cause cavitation. Cavitation is the 

implosion of bubbles of air and water vapor and makes a very distinct noise like gravel in the 

pump. The implosion of numerous bubbles will eat away at an impeller and it eventually will 

be filled with holes. 

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Pump Power Requirements 

The power added to water as it moves through a pump can be calculated with the following 

formula: 

Q x TDH 

WHP = ----------- (1) 

3960 

where: 

WHP = Water Horse Power 

Q = Flow rate in gallons per minute (GPM) 

TDH = Total Dynamic Head (feet) 

However, the actual power required to run a pump will be higher than this because pumps 

and drives are not 100 percent efficient. The horsepower required at the pump shaft to pump 

a specified flow rate against a specified TDH is the Brake Horsepower (BHP) which is 

calculated with the following formula: 

WHP 

BHP = ---------------------- (2) 

Pump Eff. x Drive Eff. 

BHP -- Brake Horsepower (continuous horsepower rating of the power unit). 

Pump Eff. -- Efficiency of the pump usually read from a pump curve and having a value 

between 0 and 1. 

Drive Eff. -- Efficiency of the drive unit between the power source and the pump. For direct 

connection this value is 1, for right angle drives the value is 0.95 and for belt drives it can 

vary from 0.7 to 0.85. 

Effect of Speed Change on Pump Performance 

The performance of a pump varies with the speed at which the impeller rotates. 

Theoretically, varying the pump speed will result in changes in flow rate, TDH and BHP 

according to the following formulas: 

RPM2 

(-----) x GPM1 = GPM2 (3) 

RPM1 

RPM2 

(-----) 2 X TDH1 = TDH2 (4) 

RPM1 

RPM2 

(-----) 3 x BPH1 = BPH2 (5) 

RPM1 

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where: 

RPM1 = Initial revolutions per minute setting 

RPM2 = New revolutions per minute setting 

GPM = Gallons per Minute 

(subscripts same as for RPM) 

TDH = Total Dynamic Head 


BHP = Brake Horsepower 


As an example, if the RPM are increased by 50 percent, the flow rate will increase by 50 

percent, the TDH will increase 2.25 times, and the required BHP will increase 3.38 times that 

required at the lower speed. It is easy to see that with a speed increase the BHP 

requirements of a pump will increase at a faster rate than the head and flow rate changes. 

Pump Efficiency 

Manufacturers determine by tests the operating characteristics of their pumps and publish 

the results in pump performance charts commonly called "pump curves." 

A typical pump curve for a horizontal centrifugal pump. NPSH is the Net Positive 

Suction Head required by the pump and TDSL is the Total Dynamic Suction Lift 

available (both at sea level). 

All pump curves are plotted with the flow rate on the horizontal axis and the TDH on the 

vertical axis. The curves in a pump curve are for a centrifugal pump tested at different RPM. 

Each curve indicates the GPM versus TDH relationship at the tested RPM. In addition, pump 

efficiency lines have been added and wherever the efficiency line crosses the pump curve 

lines that number is what the efficiency is at that point. Brake horsepower (BHP) curves have 

also been added; they slant down from left to right. The BHP curves are calculated using the 

values from the efficiency lines. At the top of the chart is an NPSH curve with its scale on the 

right side of the chart. 

Reading a Pump Curve 

When the desired flow rate and TDH are known, these curves are used to select a pump. 

The pump curve shows that a pump will operate over a wide range of conditions. However, it 

will operate at peak efficiency only in a narrow range of flow rate and TDH. As an example of 

how a pump characteristic curve is used, let's use the pump curve to determine the 

horsepower and efficiency of this pump at a discharge of 900 gallons per minute (GPM) and 

120 feet of TDH. 

Solution: Follow the dashed vertical line from 900 GPM until it crosses the dashed 

horizontal line from the 120 feet of TDH. At this point the pump is running at a peak efficiency 

just below 72 percent, at a speed of 1600 RPM. If you look at the BHP curves, this pump 

requires just less than 40 BHP on the input shaft. A more accurate estimate of BHP can be 

calculated with equations 1 and 2. Using equation 1, the WHP would be [900 x 120] / 3960 or 

27.3, and from equation 2 the BHP would be 27.3 / 0.72 or 37.9, assuming the drive 

efficiency is 100 percent. The NPSH curve was used to calculate the Total Dynamic Suction 

Lift (TDSL) markers at the bottom of the chart. Notice that the TDSL at 1400 GPM is 10 feet, 

but at 900 GPM the TDSL is over 25 feet. 

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Changing Pump Speed 

In addition, suppose this pump is connected to a diesel engine. By varying the RPM of the 

engine we can vary the flow rate, the TDH and the BHP requirements of this pump. As an 

example, let's change the speed of the engine from 1600 RPM to 1700 RPM. What effect 

does this have on the GPM, TDH and BHP of the pump? 

Solution: We will use equations 3, 4 and 5 to calculate the change. Using equation 3, the 

change in GPM would be (1700/1600) x 900, which equals 956 GPM. Using equation 4, the 

change in TDH would be (1700/1600) 2 x 120, which equals 135.5 feet of TDH. Using 

equation 5, the change in BHP would be (1700/1600) 3 x 37.9, which equals 45.5 BHP. This 

point is plotted on Figure 2 as the circle with the dot in the middle. Note that the new 

operating point is up and to the right of the old point and that the efficiency of the pump has 

remained the same. 

When a pump has been selected for installation, a copy of the pump curve should be 

provided by the installer. In addition, if the impeller(s) was trimmed, this information should 

also be provided. This information will be valuable in the future, especially if repairs have to 

be made. 

Determining Friction Losses 

A well system installer and/or engineer can help in determining the friction losses in the 

distribution system. There are numerous friction loss tables with values of equivalent feet of 

head for given flow rates and types and diameters of pipe available. However, unless great 

distances or small diameter pipes are used, friction loss is almost negligible. The lift 

requirements for the pump primarily include the height to which the pump must deliver the 

water from the wellhead, plus the distance from the pumping level to the land surface. 

For example: A municipal supply well has been tested and determined to yield 500gpm. 

The well was constructed with 10 inch casing that has been perforated from 200 to 500 feet 

below the ground surface within an unconfined aquifer. The static water level has been 

measured at 100 feet while the drawdown at 500gpm has been estimated at 80 feet. The full 

level of the storage tank for the well exerts about 87psi at the wellhead and is connected to 

the well via a 12-inch distribution main. Three-phase power is available and 4-inch column 

pipe is to be used down the hole. The pump intake is to be set at 180 feet. 

Before we can select an appropriate pump, we first need to determine what the total dynamic 

head is. After referring to a friction loss table for flow in 4 inch and 12-inch pipe; we 

determine that the friction losses in the 4 inch pipe will be about 24 feet per 100 foot, while 

losses in the 12 inch main are negligible. 

This leads us to determine that there will be about 43 feet of friction loss through the 4-inch 

pipe. We also know that the total lift is equal to the drawdown, plus the distance to the land 

surface from the static water level, plus the vertical distance to the full level of the storage 

tank. We know from physics that for every foot of water there is .433psi of pressure or 2.31ft 

of head for every 1 psi. The line pressure at the well head is equal to the height of the 

column of water above the well head, which gives us a line pressure at the well head of 87psi 

or 200 feet of water. The total lift from the pump to the wellhead 180 feet and equivalent to 

78psi. So the total dynamic head is equivalent to a lift of 380 feet or an equivalent pressure 

of about 165psi at the pump, plus about 43 feet of friction loss. Therefore, in order to pump 

500gpm under these circumstances, the pump that is selected should have its most efficient 

operating range in the neighborhood of 423 feet total lift. We then look at performance 

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curves from the various pump manufacturers to determine the best pump and power 

combination for the application. 

Because this is a municipal supply well that is pumping directly into the distribution system, 

we will choose a submersible turbine for the job rather than a line shaft turbine, which must 

be lubricated. Upon looking at the curves for this application, one will find that a 75HP, 8in, 5 

stage, submersible pump will do the job most efficiently without risking the over-pumping of 

the well. 

Elements of Total Dynamic Head for the proper selection of pumping equipment. 

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A new 8 inch submersible pump and motor with 6 inch column pipe 

about to be installed in a high capacity municipal supply well. 

The Well Head Assembly 

An approved well cap or seal is to be installed at the wellhead to prevent any contamination 

from entering the well through the top once construction is complete. When the well is 

completed with pumping equipment a well vent is also required. 

The well vent pipe should be at least ½ inch in diameter, 8 inches above the finished grade, 

and be turned down, with the opening screened with a minimum 24-mesh durable screen to 

prevent entry of insects. Only approved well casing material meeting the requirements of the 

Code may be utilized. 

In addition, frost protection should be provided by use of insulation or pump house. Turbine 

and submersible pumps are normally used. Any pressure, vent, and electric lines to and 

from the pump should enter the casing only through a watertight seal. 

Pumps and pressure tanks may be located in basements and enclosures. However, wells 

should not be located within vaults or pits, except with a variance permit. 

If the pump discharge line passes through the well casing underground, an approved pitless 

adapter should be installed. The well manifold should include an air relief valve, flow meter, 

sample port, isolation valve, and a check valve. If the well should need rehabilitation, 

additional construction, or repair, it must be done in compliance with the State or Local Water 

Well Construction Codes. 

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Water Storage Section 

Water storage facilities and tanks vary in size, shape, and application. There are different 

types that are used in the water distribution systems, such as standpipes, elevated tanks and 

reservoirs, hydropneumatic tanks and surge tanks. 

These tanks serve multiple purposes in the distribution system. Just the name alone can give 

you an idea of its purpose. 

� SURGE tanks 

� RESERVOIRS 

� ELEVATED tanks Water towers and Standpipes 

Surge Tanks 

What really causes water main breaks - ENERGY - when released in a confined space, such 

as a water distribution system. Shock waves are created when hydrants, valves, or pumps 

are opened and closed quickly, trapping the kinetic energy of moving water within the 

confined space of a piping system. 

These shock waves can create a 

turbulence that travels at the speed of 

sound, seeking a point of release. The 

release the surge usually finds is an 

elevated tank, but the surge doesn't 

always find this release quickly 

enough. Something has to give, often 

times, it's your pipe fittings. 

Distribution operators are aware of this 

phenomenon! It's called WATER 

HAMMER. 

This banging can be heard as water 

hammer. Try it at home - turn on your 

tap, then turn it off very quickly. You should hear a bang, and maybe even several. If you turn 

the tap off more slowly, it should stay quiet, as the liquid in the pipes slows down more 

gradually. 

A Surge tank should not be used for water 

storage. 

The goal of the water tower or standpipe is to store 

water high in the air, where it has lots of gravitational 

potential energy. This stored energy can be converted 

to pressure potential energy or kinetic energy for 

delivery to homes. Since height is everything, building 

a cylindrical water tower is inefficient. Most of the 

water is then near the ground. By making the tower 

wider near the top, it puts most of its water high up. 

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Giardia 

Cryptosporidium 

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Understanding Water Quality 

What’s that Stuff in the Tap Water? 

by Jameel Rahman and Gary A. Burlingame 

Jameel Rahman is a retired analytical chemist supervisor for the Materials Testing 

Laboratory at the Philadelphia Water Department, where Gary A. Burlingame is the 

supervisor of water quality and research. Contact Burlingame at gary.burlingame@phila.gov 

or (215) 685-1417. 

Reprinted from Opflow, Vol. 29, No. 2 (February 2003), by permission. Copyright 2003, 

American Water Works Association. 

Almost every water utility employee responsible for solving customer problems has fielded a 

complaint about particles in a bathtub or faucet aerator. Although particles can come from 

cold or hot water systems, household plumbing, water distribution systems, and water 

treatment, the water supplier—at least in customers’ eyes—is usually “guilty until proven 

innocent.” 

The Philadelphia Water Department has standardized procedures in place that can identify 

offending materials and help pinpoint their source. 

Collecting and Identifying Particulates 

Typically, the suspended matter customers complain about is particulate in form. The most 

important step in solving a particulate complaint is to collect as much suspect material as 

possible; making sure it represents the customer’s actual concern. Sometimes enough 

material for analysis can be collected from faucet aerators. A container may be left with the 

customer for sample collection during normal tap use. Particulates can also accumulate in 

the toilet tank. 

Particulate matter can be extracted from 

water samples by using nitrocellulose 

membrane filters. A 0.45 µm filter can be 

used if the water’s colloidal matter doesn’t 

clog the filter before enough particulate 

material is collected for analysis. Enough 

particulate matter can usually be captured 

with a water sample of approximately 250 

mL. When samples have low turbidity, 

larger volumes will need to be filtered. 

Granular Rust→ 

Under a microscope, examine the 

particulate matter captured on a filter. 

Use a zoom microscope with at least 40×, 

preferably 75×, magnification to identify matter on the membrane filter disk, which can be 

stored in a Plexiglas Petri dish. For optimum observation, illuminate the particulates from 

above with a fiber-optic light. 

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Some particulates can be identified by their appearance and, sometimes, by touching them 

with a sharp needle and observing their physical properties, such as softness, stickiness, or 

solubility in a solvent. Particulates can be quantified as few, several, or numerous. If 

particulates cannot be identified by their appearance, perform simple chemical tests on the 

filter. 

A characteristic evolution of a gas, such as carbon dioxide from scale particulates or marble, 

can be observed under the microscope. Color formed by chemical reactions can be seen by 

the unaided eye. If these tests still fail to identify the debris, or further delineation is required, 

use infrared spectroscopy (IR). 

Visual Identification 

Sand particulates have a characteristic vitreous appearance and irregular shape with 

smooth facets. They can be colorful but usually appear translucent to whitish. 

Mica particulates have a characteristic platelet shape and shine under reflected light. You 

will need to understand the common soil minerals in your area to identify them. 

Man-made fibers, found in all colors and with a characteristic wrinkled strip shape, are 

present in single strands, have significant length, and often are visible to the unaided eye. 

Usually, fibers are not present in large numbers — at most, 10 per filter. Fibers used in 

apparel are round, but fibers found in water typically have a strip shape, indicating a 

common source, such as pump packing. 

Glass chips are transparent, may have smooth facets with sharp edges, and may be 

colorful. Relatively large amounts of similar particulates often indicate a problem within a 

plumbing system. Usually the source of such particulates is disintegrating plastic, a rubber 

gasket, or a corroding component of the plumbing system. 

Heat Identification 

Activated carbon particulates are black and usually coated with debris. They can show 

porosity, but appear dull compared to anthracite particulates, which display a shiny luster 

under reflected light. Pick up a few particulates on the tip of a wetted platinum wire and burn 

them in the blue part of a Bunsen burner flame. AC particulates will burn instantaneously 

with a glitter and no visible smoke or residue. 

Disintegrated plastic particulates are usually white, large, and may be present in large 

numbers. Pick up a few particulates and burn them in a Bunsen burner flame. Plastic burns 

with a smoke. With fine-tipped tweezers, remove sufficient particulates from the disk and 

further identify them by IR. Most often they are polypropylene plastic. Disintegrated rubber 

gasket particulates are usually black, relatively large, and do not smear the filter disk with 

black when a drop of toluene is applied. If pressed with a needle, they flex. Remove a few 

particulates and burn them; rubber burns with a black smoke. Identify them further by IR. 

Often these particulates are ethylene-propylene-diene monomer, used in gaskets. 

Acid Identification 

Rust particulates are usually abundant and are easy to identify with their typically brown and 

rough irregular shapes. Large particulates may have yellow and black streaks or inclusions, 

while fine rust particulates form a uniform brown film on the filter disk. To confirm rust, add a 

drop of (1+1) hydrochloric acid (500 mL of 11.5N hydrochloric acid [HCl] solution plus 500 

mL of distilled water) to the filter. Yellow staining indicates the presence of ferric chloride. 

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Add a drop of 2 percent solution of potassium thiocyanate on the yellow area where HCl was 

added. Brick-red staining confirms the presence of potassium ferrithiocyanate. 

Large Rust Particles 

Lead solder particulates are gray and may have a whitish coating, are usually brittle, and 

can be easily pulverized. Often, they are relatively large in size compared to most other 

particulates on the filter disk. If lead particulates are suspected, add a drop of pH 2.8 

tartrate-buffer solution followed by a drop of 0.2 percent solution of freshly prepared sodium 

rhodizonate. If the particulates turn scarlet red, lead solder is present. 

Prepare a pH 2.8 buffer solution by dissolving 1.9 g of sodium bitartrate and 1.5 g of tartaric 

acid in 100 mL of distilled water. To prepare the sodium rhodizonate reagent, dissolve 0.2 g 

of rhodizonic acid disodium salt in 100 mL of distilled water. 

Patina is hydrated basic copper carbonate and has a greenish color. These irregularly 

shaped particulates result from corrosion of copper and copper alloys. To confirm their 

presence, add a drop of (1+1) HCl from a Pasture pipette. If tiny bubbles of carbon dioxide 

form under the microscope, the presence of patina is indicated. Remove a few particulates 

and place them in the cavity of a spot-test plate. Add a drop of (1+1) HCl followed by a drop 

of ammonia. Appearance of a blue precipitate or blue color confirms the presence of patina 

particulates. Rust particulates will interfere with this test if it is performed on the rust-coated 

filter. Calcium carbonate can develop as a white scale through evaporation of hard water or 

can occur as a particulate of limestone or calcite. Scales can form in water heaters. 

Limestone can come from water treatment processes. Add a drop of HCl (1+1) on the 

particulates and observe the evolution of carbon dioxide under the microscope. The brisk 

evolution of gas confirms the presence of carbonates. 

Solvent Identification 

Asphalt pipe-coating compounds are black. To differentiate between various black 

particulates, add a drop of toluene or chloroform to the filter disk under the microscope. If the 

disk becomes smeared with black around the particulates, the particulates are classified as 

pipe-coating of an asphaltic nature. Anthracite, activated carbon, and rubber particulates are 

insoluble in the solvents used. 

Anthracite particulates appear shiny compared with other black particulates and do not 

smear the filter disk if a drop of toluene is applied. These particulates can be removed from 

the filter disk and burned in a crucible; they will leave a solid residue. 

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Grease particulates are black and may be shiny. They are usually present as tiny heaps on 

the filter disk because of their softness and hydrophobic nature. They are soft and sticky 

when touched with a needle and can be smeared easily on the disk. Add a drop of toluene; 

grease will dissolve and a black color will spread around the particulates. 

Let the toluene evaporate or use an oven to expedite drying. Touch the particulates with a 

needle in the area where toluene was added; they should no longer be sticky and may 

behave like a black powder. All greases may not behave this way, but their stickiness and 

extreme softness differentiates them from other black particulates. 

Infrared Spectroscopy 

When particulates cannot be completely identified by the above means, use IR to identify 

organic and inorganic materials. Inorganic compounds include calcium carbonate, calcium 

sulfate, barium sulfate, lead carbonate, metal oxides, silicates, or phosphates. Visually, and 

with the aid of heat, you might suspect a particulate is plastic in nature, but various types of 

plastics can occur in water systems, including polypropylene, polyvinyl chloride, and 

polyethylene. IR can differentiate between plastic materials. 

Atoms in a molecule are in constant motion, changing bond angles by bending and bond 

lengths by stretching. Among these motions only certain vibrations absorb infrared radiation 

of specific energy. When portions of electromagnetic radiation are absorbed by such 

vibrations, an IR absorption band spectrum appears, which an infrared spectrometer 

records. Each compound has a unique infrared absorption spectrum, and various 

compounds can be identified by comparing absorption band positions in the IR spectrum of 

an unknown compound to band positions of known compounds. 

Particulates are removed with fine-tipped tweezers one by one from the filter disk and 

transferred to a small vial for dissolving in a solvent, or to a small agate mortar for grinding 

and mixing with KBr for making a potassium bromide (KBr) pellet. The usually brittle plastic 

fragments can be powdered easily, and 10 mg of sample is all that is commonly needed to 

produce a good infrared absorption spectrum. Inorganic materials are identified by IR 

scanning of the KBr pellet of the sample alone; organic materials are identified by scanning a 

pellet or a film of the sample cast on a KBr plate. 

Zeolite particles from a household water softener. 

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Most plastics are readily soluble in hot o-dichlorobenzene; try dissolving the sample in this 

solvent first. If soluble, cast a film of the sample on a KBr plate and scan it. If the sample is 

insoluble, evaporate the solvent completely and transfer the particulates to an agate mortar, 

make a KBr pellet, and scan the pellet. After obtaining a reasonably strong infrared 

spectrogram, the sample is identified by manual means or a computer search of a 

commercially available online IR library. 

Standard Chemical Analyses 

Chemical analyses available in most full-service water testing laboratories can be used to 

identify particulates when sufficient material is available. For example, hydrated aluminum 

oxide can occur as white slurry and be analyzed by inductively coupled plasma emission 

spectrometry after dissolving in mineral acids. 

Similarly, granules of lead solder can also be analyzed by wet chemical or instrumental 

methods. After a sample is dissolved in a mineral acid, it can be analyzed for various 

elements by atomic absorption spectrophotometry. A variety of materials, including iron 

oxides, manganese dioxides, aluminum oxides, calcium carbonates, and copper and silicate 

particulates, can be identified by common chemical analyses. 

During the late 1990s, customers in Philadelphia and across the country complained about 

white particulates clogging faucet aerators. Infrared spectroscopy revealed the particulates 

to be polypropylene, a plastic not used in the distribution system. The only common source 

for this plastic was found to be the dip tubes in residential gas hot-water heaters (see 

Opflow, December 1998). 

Eventually, the dip-tube manufacturer admitted to changing materials to a less-durable 

plastic, prompting water heater manufacturers to give rebates to customers for dip-tube 

replacements. When this issue made the TV news, Philadelphia was in a good position to 

explain the situation to customers because our procedure was already in place for testing 

and characterizing particulates. 

Dip Tube Particles 

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Table 1. Potential sources for particulate matter found in tap water 

From From 

Customer Water Supplier 

Particulate Plumbing Piping 

Activated carbon fines X 

Asphaltic lining fragments X 

Backfill sand X 

Calcium carbonate scale X X 

Cast iron rust X 

Cement lining fragments X 

Copper fragments X 

Glass chips X 

Greases and lubricants X X 

Lead fragments X 

Manganese dioxide deposits X 

Man-made fibers X 

On-site treatment device media X 

Plastic fragments X 

Rubber gasket fragments X X 

Soil minerals, mica X 

Table 2. Suspended matter classified by size 

Soluble < 0.45 µm 

Colloidal < 1.0 µm but > 0.45 µm 

Particulate > 1.0 µm 

End of Article by Jameel Rahman and Gary A. Burlingame 

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Types of Algae 

The simplest algae are single cells (e.g., the diatoms); the more complex forms consist of 

many cells grouped in a spherical colony (e.g., Volvox), in a ribbon like filament (e.g., 

Spirogyra), or in a branching thallus form (e.g., Fucus). 

The cells of the colonies are generally similar, but some are differentiated for reproduction 

and for other functions. 

Kelps, the largest algae, may attain a length of more than 200 ft (61 m). Euglena and similar 

genera are free-swimming one-celled forms that contain chlorophyll but that are also able, 

under certain conditions, to ingest food in an animal like manner. 

The green algae include most of the freshwater forms. The pond scum, a green slime found 

in stagnant water, is a green alga, as is the green film found on the bark of trees. The more 

complex brown algae and red algae are chiefly saltwater forms; the green color of the 

chlorophyll is masked by the presence of other pigments. Blue-green algae have been 

grouped with other prokaryotes in the kingdom Monera and renamed cyanobacteria. 

Pond scum is an accumulation of floating green algae on the surface of stagnant or slowly 

moving waters, such as ponds and reservoirs. One of the most common forms is Spirogyra. 

With the exception of the larger Algae -- seaweeds and kelp -- Protoctista are pretty much all 

microscopic organisms. 

Green Algae (Gamophyta & Chlorophyta) 

7000 species 

Red Algae (Rhodophyta) 

4000 species such as this Coralline Alga (Calliarthron tuberculosum) 

Other species include Diatoms (Bacillariophyta, 10,000 species) and various Plankton 

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Major Algae Groups 

Blue-green algae are the slimy stuff. Its cells lack nuclei and its pigment is 

scattered. Blue-green algae are not actually algae, they are bacteria. 

Green algae cells have nuclei and the pigment is distinct. Green algae are the 

most common algae in ponds and can be multicellular. 

Euglenoids are green or brown and swim with their flagellum, too. They are easy 

to spot because of their red eye. Euglenoids are microscopic and single celled. 

Dinoflagellates have a flagella and can swim in open waters. They are 

microscopic and single celled. 

Diatoms look like two shells that fit together. They are microscopic and single 

celled. 

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Bacteriological Monitoring Section 

Looking under a black light to identify the presence of E. coli. 

Colilert tests simultaneously detect and confirms coliform and E. coli in water samples in 24 

hours or less. 

Simply add the Colilert reagent to the sample, incubate for 24 hours, and read results. 

Colilert is easy to read, as positive coliform samples turn yellow or blue, and when E. coli is 

present, samples fluoresce under UV light. 

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Bacteriological Monitoring Section 

Most waterborne diseases and illnesses have been related to the microbiological quality of 

drinking water. The routine microbiological analysis of your water is for coliform bacteria. The 

coliform bacteria group is used as an indicator organism to determine the biological quality of 

your water. The presence of an indicator or pathogenic bacteria in your drinking water is an 

important health concern. Indicator bacteria signal possible fecal contamination, and 

therefore, the potential presence of pathogens. They are used to monitor for pathogens 

because of the difficulties in determining the presence of specific disease-causing 

microorganisms. 

Indicator bacteria are usually harmless, occur in high 

densities in their natural environment, and are easily cultured 

in relatively simple bacteriological media. Indicators in 

common use today for routine monitoring of drinking water 

include total coliforms, fecal coliforms, and Escherichia coli 

(E. coli). 

Bacteria Sampling 

Water samples for bacteria tests must always be collected in 

a sterile container. Take the sample from an inside faucet 

with the aerator removed. Sterilize by spraying a 5% 

Household beach or alcohol solution or flaming the end of the tap with a propane torch. Run 

the water for five minutes to clear the water lines and bring in fresh water. Do not touch or 

contaminate the inside of the bottle or cap. Carefully open the sample container and hold the 

outside of the cap. Fill the container and replace the top. Refrigerate the sample and 

transport it to the testing laboratory within six hours (in an ice chest). Many labs will not 

accept bacteria samples on Friday so check the lab's schedule. Mailing bacteria samples is 

not recommended because laboratory analysis results are not as reliable. Iron bacteria forms 

an obvious slime on the inside of pipes and fixtures. A water test is not needed for 

identification. Check for a reddish-brown slime inside a toilet tank or where water stands for 

several days. 

Bac-T Sample Bottle Often referred to as a Standard Sample, 100 mls, notice the white 

powder inside the bottle. That is Sodium Thiosulfate, a de-chlorination agent. Be careful not 

to wash-out this chemical while sampling. Notice the custody seal on the bottle. 

Coliform bacteria are common in the environment and are generally not harmful. However, 

the presence of these bacteria in drinking water is usually a result of a problem with the 

treatment system or the pipes which distribute water, and indicates that the water may be 

contaminated with germs that can cause disease. 

Laboratory Procedures 

The laboratory may perform the total coliform analysis in one of four methods approved by 

the U.S. EPA and your local environmental or health division: 

Methods 

The MMO-MUG test, a product marketed as Colilert, is the most common. The sample 

results will be reported by the laboratories as simply coliforms present or absent. If coliforms 

are present, the laboratory will analyze the sample further to determine if these are fecal 

coliforms or E. coli and report their presence or absence. 

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Types of Water Samples 

It is important to properly identify the type of sample you are collecting. Please indicate in the 

space provided on the laboratory form the type of sample. 

The three (3) types of samples are: 

1. Routine: Samples collected on a routine basis to monitor for contamination. Collection 

should be in accordance with an approved sampling plan. 

2. Repeat: Samples collected following a ‘coliform present’ routine sample. The number of 

repeat samples to be collected is based on the number of routine samples you normally 

collect. 

3. Special: Samples collected for other reasons. 

Examples would be a sample collected after repairs to the system and before it is placed 

back into operation or a sample collected at a wellhead prior to a disinfection injection point. 

Routine Coliform Sampling 

The number of routine samples and frequency of collection for community public water 

systems is shown in Table 3-1 below. 

Noncommunity and nontransient noncommunity public water systems will sample at 

the same frequency as a like sized community public water system if: 

1. It has more than 1,000 daily population and has ground water as a source, or 

2. It serves 25 or more daily population and utilizes surface water as a source or ground 

water under the direct influence of surface water as its source. 

Noncommunity and nontransient, noncommunity water systems with less than 1,000 daily 

population and groundwater as a source will sample on a quarterly basis. 

Water Quality Review Statements 

� What are disease causing organisms such 

as bacteria and viruses called? Pathogens 

� Name the 4 broad categories of water 

quality. Physical, chemical, biological, 

radiological. 

� What does a positive bacteriological 

sample indicate? The presence of 

bacteriological contamination. 

� When must source water monitoring for 

lead and copper be performed? When a 

public water system exceeds an action 

level for lead of copper. 

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No. of Samples per System Population 

Persons served - Samples per month 

up to 1,000 1 

1,001-2,500 2 

2,501-3,300 3 

3,301 to 4,100 4 

4,101 to 4,900 5 

4,901 to 5,800 6 

5,801 to 6,700 7 

6,701 to 7,600 8 

7,601 to 8,500 9 

8,501 to 12,900 10 

12,901 to 17,200 15 

17,201 to 21,500 20 

21,501 to 25,000 25 

25,001 to 33,000 30 

33,001 to 41,000 40 

41,001 to 50,000 50 

50,001 to 59,000 60 

59,001 to 70,000 70 

70,001 to 83,000 80 

83,001 to 96,000 90 

96,001 to 130,000 100 

130,001 to 220,000 120 

220,001 to 320,000 150 

320,001 to 450,000 180 

450,001 to 600,000 210 

600,001 to 780,000 240 

Repeat Sampling 

Repeat sampling replaces the old check sampling with a more comprehensive procedure to try to 

identify problem areas in the system. Whenever a routine sample has total coliform or fecal 

coliform present, a set of repeat samples must be collected within 24 hours after being notified by 

the laboratory. The follow-up for repeat sampling is: 

1. If only one routine sample per month or quarter is required, four (4) repeat samples must be 

collected. 

2. For systems collecting two (2) or more routine samples per month, three (3) repeat samples 

must be collected. 

3. Repeat samples must be collected from: 

a. The original sampling location of the coliform present sample. 

b. Within five (5) service connections upstream from the original sampling location. 

c. Within five (5) service connections downstream from the original sampling location. 

d. Elsewhere in the distribution system or at the wellhead, if necessary. 

4. If the system has only one service connection, the repeat samples must be collected from the 

same sampling location over a four-day period or on the same day. 

5. All repeat samples are included in the MCL compliance calculation. 

6. If a system which normally collects fewer than five (5) routine samples per month has a coliform 

present sample, it must collect five (5) routine samples the following month or quarter regardless of 

whether an MCL violation occurred or if repeat sampling was coliform absent. 

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Positive or Coliform Present Results 

What do you do when your sample is positive or coliform present? 

When you are notified of a positive test result you need to contact either the Drinking Water 

Program or your local county health department within 24 hours, or by the next business day 

after the results are reported to you. The Drinking Water Program contracts with many of the 

local health departments to provide assistance to water systems. 

After you have contacted an agency for assistance, 

you will be instructed as to the proper repeat sampling 

procedures and possible corrective measures for 

solving the problem. It is very important to initiate the 

repeat sampling immediately as the corrective 

measures will be based on those results. 

Some examples of typical corrective measures to 

coliform problems are: 

1. Shock chlorination of a ground water well. The recommended dose of 5% household 

bleach is 2 cups per 100 gallons of water in the well. This should be done anytime the bell is 

opened for repair (pump replacement, etc.). If you plan to shock the entire system, calculate 

the total gallonage of storage and distribution. 

2. Conduct routine distribution line flushing. Install blowoffs on all dead end lines. 

3. Conduct a cross connection program to identify all connections with non-potable water 

sources. Eliminate all of these connections or provide approved backflow prevention devices. 

4. Upgrade the wellhead area to meet current construction standards as set by your state 

environmental or health agency. 

5. If you continuously chlorinate, review your operation and be sure to maintain a detectable 

residual (0.2 mg/l free chlorine) at all times in the distribution system. 

6. Perform routine cleaning of the storage system. 

This list provides some basic operation and maintenance procedures that could help 

eliminate potential bacteriological problems, check with your state drinking water section or 

health department for further instructions. 

Maximum Contaminant Levels (MCLs) 

State and federal laws establish standards for drinking water quality. Under normal 

circumstances when these standards are being met, the water is safe to drink with no threat 

to human health. These standards are known as maximum contaminant levels (MCL). When 

a particular contaminant exceeds its MCL a potential health threat may occur. 

The MCLs are based on extensive research on toxicological properties of the contaminants, 

risk assessments and factors, short term (acute) exposure, and long term (chronic) 

exposure. You conduct the monitoring to make sure your water is in compliance with the 

MCL. 

There are two types of MCL violations for coliform bacteria. The first is for total coliform; the 

second is an acute risk to health violation characterized by the confirmed presence of fecal 

coliform or E. coli. 

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Heterotrophic Plate Count 

Heterotrophic Plate Count (HPC) --- formerly known as the standard plate count, is a procedure 

for estimating the number of live heterotrophic bacteria and measuring changes during water 

treatment and distribution in water or in swimming pools. Colonies may arise from pairs, chains, 

clusters, or single cells, all of which are included in the term "colony-forming units" (CFU). 

Method: 

There are three methods for standard plate count: 

1. Pour Plate Method 

The colonies produced are relatively small and compact, showing 

less tendency to encroach on each other than those produced by 

surface growth. On the other hand, submerged colonies often are 

slower growing and are difficult to transfer. 

2. Spread Plate Method 

All colonies are on the agar surface where they can be distinguished 

readily from particles and bubbles. Colonies can be transferred 

quickly, and colony morphology can be easily discerned and compared to published 

descriptions. 

3. Membrane Filter Method 

This method permits testing large volumes of low-turbidity water and is the method of choice for 

low-count waters. 

Material 

i ) Apparatus 

Glass rod 

Erlenmeyer flask 

Graduated Cylinder 

Pipette 

Petri dish 

Incubator 

ii ) Reagent and sample 

Reagent-grade water 

Nutrient agar 

Sample 

Procedure* 

1. Boil mixture of nutrient agar and nutrient broth for 15 minutes, then cool for about 20 minutes. 

2. Pour approximately 15 ml of medium in each Petri dish, let medium solidify. 

3. Pipette 0.1 ml of each dilution onto surface of pre-dried plate, starting with the highest dilution. 

4. Distribute inoculum over surface of the medium using a sterile bent glass rod. 

5. Incubate plates at 35 o C for 48h. 

6. Count all colonies on selected plates promptly after incubation, consider only plates having 30 

to 300 colonies in determining the plate count. 

*Duplicate samples 

Computing and Reporting: 

Compute bacterial count per milliliter by the following equation: 

CFU/ml = colonies counted / actual volume of sample in dish a)If there is no plate with 30 to 

300 colonies, and one or more plates have more than 300 colonies, use the plate(s) having 

a count nearest 300 colonies. 

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) If plates from all dilutions of any sample have no colony, report the count as less than 

1/actual volume of sample in dish estimated CFU/ml. 

c) Avoid creating fictitious precision and accuracy when computing CFU by recording only 

the first two left-hand digits. 

Heterotrophic Plate Count 

(Spread Plate Method) 

Heterotrophic organisms utilize organic compounds as their carbon source (food or 

substrate). In contrast, autotrophic organisms use inorganic carbon sources. The 

Heterotrophic Plate Count provides a technique to quantify the bacteriological activity of a 

sample. The R2A agar provides a medium that will support a large variety of heterotrophic 

bacteria. After an incubation period, a bacteriological colony count provides an estimate of 

the concentration of heterotrophs in the sample of interest. 

Laboratory Equipment Needed 

100 x 15 Petri Dishes 

Turntable 

Glass Rods: Bend fire polished glass rod 45 degrees 

about 40 mm from one end. Sterilize before using. 

Pipette: Glass, 1.1 mL. Sterilize before using. 

Quebec Colony Counter 

Hand Tally Counter 

Reagents 

1) R2A Agar: Dissolve and dilute 0.5 g of yeast 

extract, 0.5 g of proteose peptone No. 3, 0.5 g of 

casamino acids, 0.5 g of glucose, 0.5 g of soluble 

starch, 0.3 g of dipotassium hydrogen phosphate, 

0.05 g of magnesium sulfate heptahydrate, 0.3 g of sodium pyruvate, 15.0 g of agar to 1 L. 

Adjust pH to 7.2 with dipotassium hydrogen phosphate before adding agar. Heat to 

dissolve agar and sterilize at 121 C for 15 minutes. 

2) Ethanol: As needed for flame sterilization. 

Preparation of Spread Plates 

Immediately after agar sterilization, pour 15 mL of R2A agar into 

sterile 100 x 15 Petri dishes; let agar solidify. Pre-dry plates 

inverted so that there is a 2 to 3 g water loss overnight with the 

lids on. Use pre-dried plates immediately or store up to two 

weeks in sealed plastic bags at 4°C. 

Sample Preparation 

Mark each plate with sample type, dilution, date, and any other 

information before sample application. 

Prepare at least duplicate plates for each volume of sample or 

dilution examined. Thoroughly mix all samples by rapidly 

making about 25 complete up-and-down movements. 

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Sample Application 

Uncover pre-dried agar plate. Minimize time plate remains uncovered. Pipette 0.1 or 0.5 mL 

sample onto surface of pre-dried agar plate. 

Record Volume of Sample Used. 

Using a sterile bent glass rod, distribute the sample over surface of the medium by rotating 

the dish by hand on a turntable. Let the sample be absorbed completely into the medium 

before incubating. Put cover back on Petri dish and invert for duration of incubation time. 

Incubate at 28°C for 7 days. Remove Petri dishes from incubator for counting. 

Counting and Recording 

After incubation period, promptly count all colonies on the plates. To count, uncover plate 

and place on Quebec colony counter. Use a hand tally counter to maintain count. Count all 

colonies on the plate, regardless of size. Compute bacterial count per milliliter by the 

following equation: 

colonies counted 

CFU mL � 

actual volume of sample in dish, mL 

To report counts on a plate with no colonies, report the count as less than one (

Total Coliforms 

This MCL is based on the presence of total coliforms, and compliance is on a monthly or 

quarterly basis, depending on your water system type and state rule. For systems which 

collect fewer than 40 samples per month, no more than one sample per month may be 

positive. In other words, the second positive result (repeat or routine) in a month or quarter 

results in an MCL violation. 

For systems which collect 40 or more samples per month, no more than five (5) percent may 

be positive. Check with your state drinking water section or health department for further 

instructions. 

Acute Risk to Health (Fecal Coliforms and E. coli) 

An acute risk to human health violation occurs if either one of the following happen: 

1. A routine analysis shows total coliform present and is followed by a repeat analysis which 

indicates fecal coliform or E. coli present. 

2. A routine analysis shows total and fecal coliform or E. coli present and is followed by a 

repeat analysis which indicates total coliform present. An acute health risk violation requires 

the water system to provide public notice via radio and television stations in the area. This 

type of contamination can pose an immediate threat to human health and notice must be 

given as soon as possible, but no later than 72 hours after notification from your laboratory of 

the test results. 

Certain language may be mandatory for both these violations and is included in your state 

drinking water rule. 

Public Notice 

A public notice is required to be issued by a water system whenever it fails to comply with an 

applicable MCL or treatment technique, or fails to comply with the requirements of any 

scheduled variance or permit. This will inform users when there is a problem with the system 

and give them information. 

A public notice is also required whenever a water system fails to comply with its monitoring 

and/or reporting requirements or testing procedure. Each public notice must contain certain 

information, be issued properly and in a timely manner and contain certain mandatory 

language. The timing and place of posting of the public notice depends on whether an acute 

risk is present to users. Check with your state drinking water section or health department for 

further instructions. 

The following are Acute Violations 

1. Violation of the MCL for nitrate. 

2. Any violation of the MCL for total coliforms, when fecal coliforms or E. coli are present in 

the distribution system. 

3. Any outbreak of waterborne disease, as defined by the rules. 

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Pathogen Section 

Bacteria, viruses, and protozoans that cause disease are known as pathogens. Most 

pathogens are generally associated with diseases that cause intestinal illness and affect 

people in a relatively short amount of time, generally a few days to two weeks. They can 

cause illness through exposure to small quantities of contaminated water or food or from 

direct contact with infected people or animals. 

Pathogens that may cause waterborne outbreaks through drinking water have one thing in 

common: they are spread by the fecal-oral (or feces-to-mouth) route. Pathogens may get into 

water and spread when infected humans or animals pass the bacteria, viruses, and protozoa 

in their stool. For another person to become infected, he or she must take that pathogen in 

through the mouth. 

Waterborne pathogens are different from other types of pathogens such as the viruses that 

cause influenza (the flu) or the bacteria that cause tuberculosis. Influenza virus and 

tuberculosis bacteria are spread by secretions that are coughed or sneezed into the air by an 

infected person. 

Human or animal wastes in watersheds, failing septic systems, failing sewage treatment 

plants or cross-connections of water lines with sewage lines provide the potential for 

contaminating water with pathogens. The water may not appear to be contaminated because 

feces has been broken up, dispersed and diluted into microscopic particles. These particles, 

containing pathogens, may remain in the water and be passed to humans or animals unless 

adequately treated. 

Only proper treatment will ensure eliminating the spread of disease. In addition to water, 

other methods exist for spreading pathogens by the fecal-oral route. The foodborne route is 

one of the more common methods. A frequent source is a food handler who does not wash 

his hands after a bowel movement and then handles food with “unclean” hands. The 

individual who eats feces-contaminated food may become infected and ill. It is interesting to 

note the majority of foodborne diseases occur in the home, not restaurants. 

Day care centers are another common source for 

spreading pathogens by the fecal-oral route. Here, 

infected children in diapers may get feces on their 

fingers, then put their fingers in a friend’s mouth or 

handle toys that other children put into their 

mouths. You will usually be asked to sample for 

Giardia at these facilities. 

The general public and some of the medical community usually refer to diarrhea symptoms 

as “stomach flu.” Technically, influenza is an upper respiratory illness and rarely has 

diarrhea associated with it; therefore, stomach flu is a misleading description for foodborne or 

waterborne illnesses, yet is accepted by the general public. So the next time you get the 

stomach flu, you may want to think twice about what you’ve digested within the past few 

days. 

More on this subject in the Microorganism Appendix. 

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Chain of Transmission 

Water is contaminated with feces. This contamination may be of human or animal origin. The 

feces must contain pathogens (disease-causing bacteria, viruses or protozoa). If the human 

or animal source is not infected with a pathogen, no disease will result. The pathogens must 

survive in the water. This depends on the temperature of the water and the length of time the 

pathogens are in the water. Some pathogens will survive for only a short time in water, 

others, such as Giardia or Cryptosporidium, may survive for months. 

The pathogens in the water must enter the water system’s intake in numbers sufficient to 

infect people. The water is either not treated or inadequately treated for the pathogens 

present. A susceptible person must drink the water that contains the pathogen; then illness 

(disease) will occur. This chain lists the events that must occur for the transmission of 

disease via drinking water. By breaking the chain at any point, the transmission of disease 

will be prevented. 

Bacterial Diseases 

Campylobacteriosis is the most common diarrheal illness caused by bacteria. Other 

symptoms include abdominal pain, malaise, fever, nausea and vomiting; and begin three to 

five days after exposure. The illness is frequently over within two to five days and usually 

lasts no more than 10 days. Campylobacteriosis outbreaks have most often been 

associated with food, especially chicken and un-pasteurized milk, as well as un-chlorinated 

water. These organisms are also an important cause of “travelers’ diarrhea.” Medical 

treatment generally is not prescribed for campylobacteriosis because recovery is usually 

rapid. 

Cholera, Legionellosis, salmonellosis, shigellosis, yersiniosis, are other bacterial 

diseases that can be transmitted through water. All bacteria in water are readily killed or 

inactivated with chlorine or other disinfectants. 

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Viral Diseases 

Hepatitis A is an example of a common viral disease that may be transmitted through water. 

The onset is usually abrupt with fever, malaise, loss of appetite, nausea and abdominal 

discomfort, followed within a few days by jaundice. The disease varies in severity from a mild 

illness lasting one to two weeks, to a severely disabling disease lasting several months 

(rare). The incubation period is 15-50 days and averages 28-30 days. Hepatitis A outbreaks 

have been related to fecally contaminated water; food contaminated by infected food 

handlers, including sandwiches and salads that are not cooked or are handled after cooking, 

and raw or undercooked mollusks harvested from contaminated waters. Aseptic meningitis, 

polio and viral gastroenteritis (Norwalk agent) are other viral diseases that can be 

transmitted through water. Most viruses in drinking water can be inactivated by chlorine or 

other disinfectants. 

Protozoan Diseases 

Protozoan pathogens are larger than bacteria and viruses, but still microscopic. They invade 

and inhabit the gastrointestinal tract. Some parasites enter the environment in a dormant 

form, with a protective cell wall called a “cyst.” The cyst can survive in the environment for 

long periods of time and be extremely resistant to conventional disinfectants such as 

chlorine. Effective filtration treatment is therefore critical to removing these organisms from 

water sources. 

Giardia lamblia 


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Giardiasis is a commonly reported protozoan-caused disease. It has also been referred to 

as “backpacker’s disease” and “beaver fever” because of the many cases reported among 

hikers and others who consume untreated surface water. Symptoms include chronic 

diarrhea, abdominal cramps, bloating, frequent loose and pale greasy stools, fatigue and 

weight loss. The incubation period is 5-25 days or longer, with an average of 7-10 days. 

Many infections are asymptomatic (no symptoms). Giardiasis occurs worldwide. Waterborne 

outbreaks in the United States occur most often in communities receiving their drinking water 

from streams or rivers without adequate disinfection or a filtration system. The organism, 

Giardia lamblia, has been responsible for more community-wide outbreaks of disease in the 

U.S. than any other pathogen. Drugs are available for treatment, but these are not 100% 

effective. 

Giardia lamblia 

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Cryptosporidiosis 

Cryptosporidiosis is an example of a protozoan disease that is common worldwide, but was 

only recently recognized as causing human disease. The major symptom in humans is 

diarrhea, which may be profuse and watery. 

The diarrhea is associated with cramping abdominal pain. General malaise, fever, anorexia, 

nausea, and vomiting occur less often. Symptoms usually come and go, and end in fewer 

than 30 days in most cases. The incubation period is 1-12 days, with an average of about 

seven days. Cryptosporidium organisms have been identified in human fecal specimens from 

more than 50 countries on six continents. 

The mode of transmission is fecal-oral, either by person-to-person or animal-to-person. 

There is no specific treatment for Cryptosporidium infections. All these diseases, with the 

exception of hepatitis A, have one symptom in common: diarrhea. They also have the same 

mode of transmission, fecal-oral, whether through person-to-person or animal-to-person 

contact, and the same routes of transmission, being either foodborne or waterborne. 

Although most pathogens cause mild, self-limiting disease, on occasion, they can cause 

serious, even life threatening illness. Particularly vulnerable are persons with weak immune 

systems, such as those with HIV infections or cancer. 

By understanding the nature of waterborne diseases, the importance of properly constructed, 

operated and maintained public water systems becomes obvious. While water treatment 

cannot achieve sterile water (no microorganisms), the goal of treatment must clearly be to 

produce drinking water that is as pathogen-free as possible at all times. 

For those who operate water systems with inadequate source protection or treatment 

facilities, the potential risk of a waterborne disease outbreak is real. For those operating 

systems that currently provide adequate source protection and treatment, operating and 

maintaining the system at a high level on a continuing basis is critical to prevent disease. 


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Waterborne Diseases 

Name Causative organism Source of organism Disease 

Viral 

gastroenteritis 

Rotavirus (mostly in young 

children) 

Norwalk Agent Noroviruses (genus Norovirus, 

family Caliciviridae) *1 

Human feces Diarrhea 

or vomiting 

Human feces; also, 

shellfish; lives in polluted 

waters 

Diarrhea and 

vomiting 

Salmonellosis Salmonella (bacterium) Animal or human feces Diarrhea or 

vomiting 

Gastroenteritis 

Escherichia coli 

-- E. coli O1 57:H7 (bacterium): 

Other E. coli organisms: 

Human feces Symptoms vary 

with type caused 

Typhoid Salmonella typhi (bacterium) Human feces, urine Inflamed intestine, 

enlarged spleen, 

high temperaturesometimes 

fatal 

Shigellosis Shigella (bacterium) Human feces Diarrhea 

Cholera Vibrio choleras (bacterium) Human feces; also, 

shellfish; lives in many 

coastal waters 

Hepatitis A Hepatitis A virus Human feces; shellfish 

grown in polluted waters 

Amebiasis Entamoeba histolytica 

(protozoan) 

Vomiting, severe 

diarrhea, rapid 

dehydration, 

mineral loss-high 

mortality 

Yellowed skin, 

enlarged liver, 

fever, vomiting, 

weight loss, 

abdominal painlow 

mortality, lasts 

up to four months 

Human feces Mild diarrhea, 

dysentery, extra 

intestinal infection 

Giardiasis Giardia lamblia (protozoan) Animal or human feces Diarrhea, 

cramps, nausea, 

and general 

weakness — lasts 

one week to 

months 

Cryptosporidiosis Cryptosporidium parvum Animal or human feces Diarrhea, stomach 

pain — lasts 

(protozoan) days 

to weeks 

Notes: 

*1 http://www.cdc.gov/ncidod/dvrd/revb/gastro/norovirus.htm 

http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5009a1.htm 

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General Contaminant Information 

The sources of drinking water include rivers, lakes, streams, ponds, reservoirs, springs, and 

wells. As water travels over the surface of the land or through the ground, it dissolves 

naturally occurring minerals and in some cases, radioactive material, and can pick up 

substances resulting from the presence of animals or human activity. 

Contaminants that may be present in sources of drinking water include: 

Microbial contaminants, such as viruses and bacteria, which may come from sewage 

treatment plants, septic systems, agricultural livestock operations and wildlife; 

Inorganic contaminants, such as salts and metals, which can be naturally occurring or 

result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and 

gas production, mining or farming; 

Pesticides and herbicides, which may come from a variety of sources such as agriculture, 

urban stormwater run-off, and residential uses; 

Organic chemical contaminants, including synthetic and volatile organic chemicals, which 

are by-products of industrial processes and petroleum production, and can also come from 

gas stations, urban stormwater run-off, and septic systems; 

Radioactive contaminants, which can be naturally occurring or be the result of oil and gas 

production and mining activities. 

Background 

Coliform bacteria and chlorine residual are the only routine sampling and monitoring 

requirements for small ground water systems with chlorination. The coliform bacteriological 

sampling is governed by the Total Coliform Rule (TCR) of the SDWA. Although there is 

presently no requirement for chlorination of groundwater systems under the SDWA, State 

regulations require chlorine residual monitoring of those systems that do chlorinate the water. 

TCR The TCR requires all Public Water Systems (PWS) to monitor their distribution system 

for coliform bacteria according to the written sample sitting plan for that system. The sample 

sitting plan identifies sampling frequency and locations throughout the distribution system 

that are selected to be representative of conditions in the entire system. Coliform 

contamination can occur anywhere in the system, possibly due to problems such as; low 

pressure conditions, line breaks, or well contamination, and therefore routine monitoring is 

required. A copy of the sample sitting plan for the system should be kept on file and 

accessible to all who are involved in the sampling for the water system. 

Number of Monthly Samples 

The number of samples to be collected monthly depends on the size of the system. The TCR 

specifies the minimum number of coliform samples collected, but it may be necessary to take 

more than the minimum number in order to provide adequate monitoring. 

This is especially true if the system consists of multiple sources, pressure zones, booster 

pumps, long transmission lines, or extensive distribution system piping. Since timely 

detection of coliform contamination is the purpose of the sample sitting plan, sample sites 

should be selected to represent the varying conditions that exist in the distribution system. 

The sample sitting plan should be updated as changes are made in the water system, 

especially the distribution system. 

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Sampling Procedures 

The sample sitting plan must be followed and all operating staff must be clear on how to 

follow the sampling plan. In order to properly implement the sample sitting plan, staff must be 

aware of how often sampling must be done, the proper procedures and sampling containers 

to be used for collecting the samples, and the proper procedures for identification, storage 

and transport of the samples to an approved laboratory. 

In addition, proper procedures must be followed for repeat sampling whenever a routine 

sample result is positive for total coliform. The following diagram outlines the requirements 

for responding to a positive Total Coliform sample. 

Troubleshooting Table for Sampling Monitoring 

Problem 

1. Positive Total Coliform. 

2. Chlorine taste and odor. 

3. Inability to maintain an adequate free chlorine residual at the furthest points of the 

distribution system or at dead end lines. 

Possible Causes 

1A. Improper sampling technique. 

1B. Contamination entering distribution system. 

1C. Inadequate chlorine residual at the sampling site. 

1D. Growth of biofilm in the distribution system. 

2A. High total chlorine residual and low free residual. 

3A. Inadequate chlorine dose at treatment plant. 

3B. Problems with chlorine feed equipment. 

3C. Ineffective distribution system flushing program. 


Possible Solutions 

1A/ Check distribution system for low pressure conditions, possibly due to line breaks or 

excessive flows that may result in a backflow problem. 

1B. Insure that all staff are properly trained in sampling and transport procedures as 

described in the TCR. 

1C. Check the operation of the chlorination feed system. Refer to issues described in the 

sections on pumps and hypochlorination systems. Insure that residual test is being 

performed properly. 

1D. Thoroughly flush effected areas of the distribution system. Superchlorination may be 

necessary in severe cases. 

2A. The free residual should be at least 85% of the total residual. Increase the chlorine dose 

rate to get past the breakpoint in order to destroy some of the combined residual that causes 

taste and odor problems. Additional system flushing may also be required. 

3A. Increase chlorine feed rate at point of application. 

3B. Check operation of chlorination equipment. 

3C. Review distribution system flushing program and implement improvements to address 

areas of inadequate chlorine residual. 

3D. Increase flushing in area of biofilm problem. 

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General Contaminant Information 

The sources of drinking water include rivers, lakes, streams, ponds, reservoirs, springs, and 

wells. As water travels over the surface of the land or through the ground, it dissolves naturally 

occurring minerals and in some cases, radioactive material, and can pick up substances resulting 

from the presence of animals or human activity. 

Contaminants that may be present in sources of drinking water include: 

Microbial contaminants, such as viruses and bacteria, which may come from sewage 

treatment plants, septic systems, agricultural livestock operations and wildlife; Inorganic 

contaminants, such as salts and metals, which can be naturally occurring or result from urban 

stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining 

or farming; Pesticides and herbicides, which may come from a variety of sources such as 

agriculture, urban stormwater run-off and residential uses; Organic chemical contaminants, 

including synthetic and volatile organic chemicals, which are by-products of industrial processes 

and petroleum production, and can also come from gas stations, urban stormwater run-off and 

septic systems; Radioactive contaminants, which can be naturally occurring or be the result of oil 

and gas production and mining activities. 

Background 

Coliform bacteria and chlorine residual are the only routine sampling and monitoring requirements 

for small ground water systems with chlorination. The coliform bacteriological sampling is 

governed by the Total Coliform Rule (TCR) of the SDWA. Although there is presently no 

requirement for chlorination of groundwater systems under the SDWA, State regulations require 

chlorine residual monitoring of those systems that do chlorinate the water. 

TCR The TCR requires all Public Water Systems (PWS) to monitor their distribution system for 

coliform bacteria according to the written sample siting plan for that system. The sample sitting 

plan identifies sampling frequency and locations throughout the distribution system that are 

selected to be representative of conditions in the entire system. Coliform contamination can occur 

anywhere in the system, possibly due to problems such as; low pressure conditions, line breaks, 

or well contamination, and therefore routine monitoring is required. A copy of the sample siting 

plan for the system should be kept on file and accessible to all who are involved in the sampling 

for the water system. 

Number of Monthly Samples The number of samples to be collected monthly depends on the 

size of the system. The TCR specifies the minimum number of coliform samples collected but it 

may be necessary to take more than the minimum number in order to provide adequate 

monitoring. This is especially true if the system consists of multiple sources, pressure zones, 

booster pumps, long transmission lines, or extensive distribution system piping. Since timely 

detection of coliform contamination is the purpose of the sample siting plan, sample sites should 

be selected to represent the varying conditions that exist in the distribution system. The sample 

siting plan should be updated as changes are made in the water system, especially the 

distribution system. 

Sampling Procedures The sample siting plan must be followed and all operating staff must be 

clear on how to follow the sampling plan. In order to properly implement the sample siting plan, 

staff must be aware of how often sampling must be done, the proper procedures and sampling 

containers to be used for collecting the samples, and the proper procedures for identification, 

storage and transport of the samples to an approved laboratory. In addition, proper procedures 

must be followed for repeat sampling whenever a routine sample result is positive for total 

coliform. The following diagram outlines the requirements for responding to a positive Total 

Coliform sample. 

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There is nothing in the lab that is difficult to understand or eventually master. All 

of you should be able to learn and master the basic lab procedures. Don’t be 

intimidated, learn to take samples and learn all you can about the lab, it is an 

excellent career. Bottom, normal sampling supplies. 

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Chain of Custody Procedures 

Because a sample is physical evidence, chain of custody procedures are used to maintain and 

document sample possession from the time the sample is collected until it is introduced as 

evidence. Chain of custody requirements will vary from agency to agency. 

However, these procedures are similar and the chain of custody outlined in this manual is only a 

guideline. Consult your project manager for specific requirements. 

If you have physical possession of a sample, have it in view, or have physically secured it to 

prevent tampering then it is defined as being in “custody." A chain of custody record, therefore, 

begins when the sample containers are obtained from the laboratory. From this point on, a chain 

of custody record will accompany the sample containers. 

Handle the samples as little as possible in the field. Each custody sample requires a chain of 

custody record and may require a seal. If you do not seal individual samples, then seal the 

containers in which the samples are shipped. 

When the samples transfer possession, both parties involved in the transfer must sign, date and 

note the time on the chain of custody record. If a shipper refuses to sign the chain-of-custody you 

must seal the samples and chain of custody documents inside a box or cooler with bottle seals or 

evidence tape. The recipient will then attach the shipping invoices showing the transfer dates and 

times to the custody sheets. If the samples are split and sent to more than one laboratory, 

prepare a separate chain of custody record for each sample. If the samples are delivered to afterhours 

night drop-off boxes, the custody record should note such a transfer and be locked with the 

sealed samples inside sealed boxes. 

Using alcohol to disinfect a special sample tap before obtaining a sample. 

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Chain of Custody Example. 

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Carefully follow these steps when collecting a coliform sample: 

1. Select the sampling site, which must be a faucet from which water is commonly taken for consumer 

use or a dedicated site in the distribution system. 

a. The sampling point should be a non-swivel faucet. 

b. If it is a faucet with an aerator, remove the aerator, screen and gasket and flush thoroughly. 

c. If an outside faucet is used, disconnect any hoses or other attachments and flush the line 

thoroughly. 

d. It should be a faucet that does not leak around the packing or valve mechanism. Leaking faucets 

can promote bacterial growth. 

e. Do not use fire hydrants or drinking fountains as sampling points. 

f. Do not dip sample bottles in reservoirs, spring boxes or storage tanks in order to collect a sample. 

If you have any questions about proper sampling sites, please contact your laboratory, environmental 

or health department or the state drinking water section. 

2. Use only sample bottles provided by the laboratory specifically for bacteriological sampling. 

These bottles are sterile and should not be rinsed 

before sampling. A chemical, usually sodium 

thiosulfate, is placed in the bottle by the lab and is 

used for chlorine deactivation. Do not remove it. 

3. Don’t open the sample bottle until the moment 

you are going to fill it. 

4. Flush the line thoroughly. Run water through the 

faucet for three to five minutes before opening the 

bottle and collecting the sample. 

5. Uncap the sample bottle, being careful not to 

touch the inside of the bottle with your fingers or 

other objects. Do not set the lid down while taking 

the sample. 

6. Reduce the water flow to a slow steady stream. 

Continue flushing for at least 1-2 minutes, then 

gently fill the sample bottle to the fill mark. 

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At least 100 ml. of water is necessary for analysis. Leave an air space in the top of the bottle. Do not 

overfill. 

7. Replace the cap immediately, making sure it is tight and does not leak. 

8. Label the laboratory form. Complete the following information: 

a. Your Public Water System (PWS) ID number. 

b. Your water system name, address, city and phone number. 

c. Collection date and time. 

d. Type of sample: Routine, Repeat, and Special. Refer to previous discussion of definitions. 

e. Name of person collecting sample and sample location. 

f. Free chlorine residual if your system is chlorinated. The residual should be measured at the time of 

sample collection. 

g. Complete the section for the return address where the report is to be sent. 

9. Package the sample for delivery to the laboratory. Be sure to include the lab form. The sample 

should be kept cool if at all possible. 

10. Mail or deliver the sample to the lab immediately. Samples over 30 hours old will not be analyzed 

by the laboratory. If the sample is too old or leaks in transit, the lab will notify you and you must collect 

another. 

Various water sample bottles and chain-of-custody form. 

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Sampling Plan Example 

A written sampling plan must be developed by the water system. These plans will be reviewed by the 

Health Department or State Drinking Water agency during routine field visits for sanitary surveys or 

technical assistance visits. This plan should include: 

1. The location of routine sampling sites on a system distribution map. You will need to locate more 

routine sampling sites than the number of samples required per month or quarter. A minimum of three 

sites is advised and the sites should be rotated on a regular basis. 

2. Map the location of repeat sampling sites for the routine sampling sites. Remember that repeat 

samples must be collected within five (5) connections upstream and downstream from the routine 

sample sites. 

3. Establish a sampling frequency of the routine sites. 

4. Sampling technique, establish a minimum flushing time and requirements for free chlorine residuals 

at the sites (if you chlorinate continuously). 

The sampling sites should be representative of the distribution network and pressure zones. If 

someone else, e.g., the lab, collects samples for you, you should provide them with a copy of your 

sampling plan and make sure they have access to all sample sites. 

This fellow is taking a sample from a stream to check the water quality. 

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Collection of Surface Water Samples 

Representative samples may be collected from rivers, streams and lakes if certain rules are followed: 

1. Watch out for flash floods! If a flooding event is likely and samples must be obtained, always 

go in two-person teams for safety. Look for an easy route of escape. 

2. Select a sampling location at or near a gauging station, so that stream discharge can be 

related to water-quality loading. If no gauging station exists, then measure the flow rate at the 

time of sampling, using the streamflow method described below. 

3. Locate a straight and uniform channel for sampling. 

4. Unless specified in the sampling plan, avoid sampling locations next to confluences or point 

sources of contamination. 

5. Use bridges or boats for deep rivers and lakes where wading is dangerous or impractical. 

6. Do not collect samples along a bank, as they may not be representative of the surface water 

body as a whole. 

7. Use appropriate gloves when collecting the sample. 

Streamflow Measurement 

Before collecting water quality samples, record the stream's flow rate at the selected station. The flow 

rate measurement is important for estimating contaminant loading and other impacts. 

The first step in streamflow measurement is selecting a cross-section. Select a straight reach where 

the stream bed is uniform and relatively free of boulders and aquatic growth. Be certain that the flow is 

uniform and free of eddies, slack water and excessive turbulence. 

After the cross-section has been selected, determine the width of the stream by stringing a measuring 

tape from bank-to-bank at right angles to the direction of flow. Next, determine the spacing of the 

verticals. Space the verticals so that no partial section has more than 5 per cent of the total discharge 

within it. 

At the first vertical, face upstream and lower the velocity meter to the channel bottom, record its depth, 

then raise the meter to 0.8 and 0.2 of the distance from the stream surface, measure the water 

velocities at each level, and average them. Move to the next vertical and repeat the procedure until 

you reach the opposite bank. Once the velocity, depth and distance of the cross-section have been 

determined, the mid-section method can be used for determining discharge. Calculate the discharge in 

each increment by multiplying the averaged velocity in each increment by the increment width and 

averaged depth. 

(Note that the first and last stations are located at the edge of the waterway and have a depth and 

velocity of zero.) Add up the discharges for each increment to calculate total stream discharge. Record 

the flow in liters (or cubic feet) per second in your field book. 

Composite Sampling 

Composite sampling is intended to produce a water quality sample representative of the total stream 

discharge at the sampling station. If your sampling plan calls for composite sampling, use an 

automatic type sampler. 

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History of the Periodic Table 

Dimitri Mendeleev created the periodic table when he first listed the elements in order of 

atomic mass in 1869. He found that the elements with similar properties occur in a periodic 

manner. Mendeleev was able to arrange the elements in a table form where similar 

elements are found in the same column. 

How is the Periodic Table Organized? 

The periodic table is organized with eight principal vertical columns called groups and seven 

horizontal rows called periods (The groups are numbered I to VIII from left to right, and the 

periods are numbered 1 to 7 from top to bottom) . 

All the metals are grouped together on the left side of the periodic table, and all the 

nonmetals are grouped together on the right side of the periodic table. Semimetals are found 

in between the metals and nonmetals. 

What are the Eight Groups of the Periodic Table? 

� Group I: Alkali Metals - Li, Na, K, Rb, Cs, Fr 

known as alkai metals 

most reactive of the metals 

react with all nonmetals except the noble gases 

contain typical physical properties of metals (ex. shiny solids and good conductors 

of heat and electricity) softer than most familiar metals; can be cut with a knife 

� Group II: Alkaline Earth Metals-Be, Mg, Ca, Sr, Ba, Ra 

known as alkaline earth metals 

react with nonmetals, but more slowly than the Group I metals 

solids at room temperature 

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have typical metallic properties 

harder than the Group I metals 

higher melting points than the Group I metals 

� Group III: B, Al, Ga, In, Tl 

boron is a semimetal; all the others are metals 

� Group IV: C, Si, Ge, Sn, Pb 

carbon is a nonmetal; silicon and germanium are semimetals; tin and lead are 

metals 

� Group V: N, P, As, Sb, Bi 

nitrogen and phosphorus are nonmetals; arsenic and antimony are semimetals; 

bismuth is a metal 

� Group VI: O, S, Se, Te, Po 

oxygen, sulfur, and selenium are nonmetals; tellurium and polonium are 

semimetals 

� Group VII: Halogens-F, Cl, Br, I, At 

very reactive nonmetals 

� Group VIII: Noble Gases-He, Ne, Ar, Kr, Xe, Rn 

very unreactive 

Assignment 

How do the properties of metals and nonmetals differ? 

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The pH Scale 

pH: A measure of the acidity of water. The pH scale runs from 0 to 14 with 7 being the midpoint 

or neutral. A pH of less than 7 is on the acid side of the scale with 0 as the point of 

greatest acid activity. A pH of more than 7 is on the basic (alkaline) side of the scale with 14 

as the point of greatest basic activity. 

pH = (Power of Hydroxyl Ion Activity). 

The acidity of a water sample is measured on a pH scale. This scale ranges from 0 

(maximum acidity) to 14 (maximum alkalinity). The middle of the scale, 7, represents the 

neutral point. The acidity increases from neutral toward 0. 

Because the scale is logarithmic, a difference of one pH unit represents a tenfold change. 

For example, the acidity of a sample with a pH of 5 is ten times greater than that of a sample 

with a pH of 6. A difference of 2 units, from 6 to 4, would mean that the acidity is one 

hundred times greater, and so on. 

Normal rain has a pH of 5.6 – slightly acidic because of the carbon dioxide picked up in the 

earth's atmosphere by the rain. 

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Water Disinfectant Terminology 

Many water suppliers add a disinfectant to drinking water to kill germs such as giardia and e 

coli. Especially after heavy rainstorms, your water system may add more disinfectant to 

guarantee that these germs are killed. 

Chlorine. Some people who use drinking water containing chlorine well in excess of the EPA standard 

could experience irritating effects to their eyes and nose. Some people who drink water containing 

chlorine well in excess of the EPA standard could experience stomach discomfort. 

Chloramine. Some people who use drinking water containing chloramines well in excess of the EPA 

standard could experience irritating effects to their eyes and nose. Some people who drink water 

containing chloramines well in excess of the EPA standard could experience stomach discomfort or 

anemia. 

Chlorine Dioxide. Some infants and young children who drink water containing chlorine dioxide in 

excess of the EPA standard could experience nervous system effects. Similar effects may occur in 

fetuses of pregnant women who drink water containing chlorine dioxide in excess of the EPA 

standard. Some people may experience anemia. 

Disinfection Byproducts 

Disinfection byproducts form when disinfectants added to drinking water to kill germs react 

with naturally-occurring organic matter in water. 

Total Trihalomethanes. Some people who drink water containing trihalomethanes in excess of the 

EPA standard over many years may experience problems with their liver, kidneys, or central nervous 

systems, and may have an increased risk of getting cancer. 

Haloacetic Acids. Some people who drink water containing haloacetic acids in excess of the EPA 

standard over many years may have an increased risk of getting cancer. 

Bromate. Some people who drink water containing bromate in excess of the EPA standard over many 

years may have an increased risk of getting cancer. 

Chlorite. Some infants and young children who drink water containing chlorite in excess of EPA 

standard could experience nervous system effects. Similar effects may occur in fetuses of pregnant 

women who drink water containing chlorite in excess of the EPA's standard. Some people may 

experience anemia. 

MTBE is a fuel additive, commonly used in the United States to reduce carbon monoxide and ozone 

levels caused by auto emissions. Due to its widespread use, reports of MTBE detections in the 

nation's ground and surface water supplies are increasing. The Office of Water and other EPA offices 

are working with a panel of leading experts to focus on issues posed by the continued use of MTBE 

and other oxygenates in gasoline. The EPA is currently studying the implications of setting a drinking 

water standard for MTBE. 

Health advisories provide additional information on certain contaminants. Health advisories are 

guidance values based on health effects other than cancer. These values are set for different 

durations of exposure (e.g., one-day, ten-day, longer-term, and lifetime). 

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Chemical Monitoring 

The final federal rules regarding Phase II and V contaminants were promulgated by the U.S. EPA in 

1992 and initial monitoring began in January 1993. This group of contaminants consists of Inorganic 

Chemicals (IOC), Volatile Organic Chemicals (VOC) and Synthetic Organic Chemicals (SOC) and the 

rule applies to all community and non-transient non-community public water systems. 

The monitoring schedule for these contaminants is phased in by water system population size 

according to a “standardized monitoring framework” established by the U.S. EPA. This 

standardized monitoring framework establishes nine-year compliance cycles consisting of three 3-year 

compliance periods. The first compliance cycle began in January 1993 and ended December 31, 

2001, with subsequent compliance cycles following the nine-year timeframe. The three-year 

compliance period of each cycle is the standard monitoring period for the water system. 

Turbidity Monitoring 

Monitoring for turbidity is applicable to all public water systems using surface water sources or ground 

water sources under the direct influence of surface water in whole or part. Check with your state 

drinking water section or health department for further instructions. 

The maximum contaminant level for turbidity for systems that provide filtration treatment: 

1. Conventional or direct filtration: less than or equal to 0.5 NTU in at least 95% of the measurements 

taken each month. Conventional filtration treatment plants should be able to achieve a level of 0.1 

NTU with proper chemical addition and operation. 

2. Slow sand filtration, cartridge and alternative filtration: less than or equal to 1 NTU in at least 95% of 

the measurements taken each month. The turbidity levels must not exceed 5 NTU at any turbidity 

measurements must be performed on representative samples of the filtered water every four (4) hours 

that the system serves water to the public. A water system may substitute continuous turbidity 

monitoring for grab sample monitoring if it validates the continuous measurement for accuracy on a 

regular basis using a protocol approved by the Health or Drinking Water Agency, such as confirmation 

by a bench top turbidimeter. For systems using slow sand filtration, cartridge, or alternative filtration 

treatment the Health or Drinking Water Agency may reduce the sampling frequency to once per day if 

it determines that less frequent monitoring is sufficient to indicate effective filtration performance. 

Inorganic Chemical Monitoring 

All systems must monitor for inorganics. 

The monitoring for these contaminants 

is also complex with reductions, waivers 

and detections affecting the sampling 

frequency. Please refer to the 

monitoring schedules provided by your 

state health or drinking water sections 

for assistance in determining individual 

requirements. All transient noncommunity 

water systems are required 

to complete a one-time inorganic 

chemical analysis. The sample is to be 

collected at entry points (POE) to the 

distribution system representative of 

each source after any application of 

treatment. 

Nitrates 

Nitrate is an inorganic chemical that occurs naturally in some groundwater but most often is introduced 

into ground and surface waters by man. The most common sources are from fertilizers and treated 

sewage or septic systems. 

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At high levels (over 10 mg/l) it can cause the “blue baby” syndrome in young infants, which can lead 

to serious illness and even death. It is regarded as an “acute health risk” because it can quickly 

cause illness. 

Every water system must test for Nitrate at least yearly. Systems that use ground water only must test 

yearly. Systems that use surface water and those that mix surface and ground water must test every 

quarter. A surface water system may go to yearly testing if community and nontransient noncommunity 

water must do quarterly monitoring whenever they exceed 5 mg/l in a test. After 4 quarters of testing 

and the results show that the nitrate level is not going up, they may go back to yearly testing. 

Radiological Contaminants 

All community water systems shall monitor for gross alpha activity every four years for each source. 

Depending on your state rules, compliance will be based on the annual composite of 4 consecutive 

quarters or the average of the analyses of 4 quarterly samples. If the average annual concentration is 

less than one half the MCL, an analysis of a single sample may be substituted for the quarterly 

sampling procedure. 

Total Trihalomethanes (TTHM) 

All community water systems serving a population of 10,000 or more and which add a disinfectant in 

any part of the drinking water treatment process shall monitor for total trihalomethanes (TTHM). The 

MCL is 0.1 mg/l and consists of a calculation of the running average of quarterly analyses of the sum 

of the concentrations of bromodichloromethane, di-bromochloromethane, bromoform and chloroform. 

Lead and Copper Rule 

The Lead and Copper Rule was promulgated by the U.S. EPA on June 7, 1991, with monitoring to 

begin in January 1992 for larger water systems. This rule applies to all community and nontransient, 

noncommunity water systems and establishes action levels for these two contaminants at the 

consumer’s tap. Action levels of 0.015 mg/l for lead and 1.3 mg/l for copper have been established. 

This rule establishes maximum contaminant level goals (MCLGs) for lead and copper, treatment 

technique requirements for optimal corrosion control, source water treatment, public education and 

lead service line replacement. Whenever an action level is exceeded, the corrosion control treatment 

requirement is triggered. This is determined by the concentration measured in the 90th percentile 

highest sample from the samples collected at consumers’ taps. Sample results are assembled in 

ascending order (lowest to highest) with the result at the 90th percentile being the action level for the 

system. For example, if a water system collected 20 samples, the result of the 18th highest sample 

would be the action level for the system. 

The rule also includes the best available technology (BAT) for complying with the treatment technique 

requirements, mandatory health effects language for public notification of violations and analytical 

methods and laboratory performance requirements. 

Initial monitoring began in January 1992 for systems with a population of 50,000 or more, in July 1992 

for medium-sized systems (3,300 to 50,000 population) and in July 1993 for small-sized systems (less 

than 3,300 population), 

One-liter tap water samples are to be collected at high-risk locations by either water system personnel 

or residents. Generally, high-risk locations are homes with lead-based solder installed after 1982 or 

with lead pipes or service lines. If not enough of these locations exist in the water system, the rule 

provides specific guidelines for selecting other sample sites. 

The water must be allowed to stand motionless in the plumbing pipes for at least six (6) hours and 

collected from a cold water tap in the kitchen or bathroom. It is a first draw sample, which means the 

line is not to be flushed prior to sample collection. The number of sampling sites is determined by the 

population of the system and sample collection consists of two, six-month monitoring periods; check 

with your state rule or drinking water section for more information. 

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Sampling Sites by Population 

System size - No. of sites - No. of sites 

(no. of persons served) (standard monitoring) (reduced monitoring) 

>100,000 100 50 

10,001-100,000 60 30 

3,301 to 10,000 40 20 

501 to 3,300 20 10 

101 to 500 10 5 

< 100 5 5 

If a system meets the lead and copper action levels or maintains optimal corrosion control treatment 

for two consecutive six-month monitoring periods, then reduced monitoring is allowed and sampling 

frequency drops to once per year. After three consecutive years of reduced monitoring, sample 

frequency drops to once every three years. In addition to lead and copper testing, all large water 

systems and those medium- and small-sized systems that exceed the lead or copper action levels will 

be required to monitor for the following water quality parameters: pH, alkalinity, calcium, conductivity, 

orthophosphate, silica and water temperature. 

These parameters are used to identify optimal corrosion control treatment and determine compliance 

with the rule once treatment is installed. The sampling locations for monitoring water quality 

parameters are at entry points and representative taps throughout the distribution system. 

Coliform sampling sites can be used for distribution system sampling. The number of sites required for 

monitoring water quality during each six-month period is shown below. 

Number of Water Quality Parameters per Population 

System size # of sites for water (no. of persons served) quality parameters 

>100,000 25 

10,001-100,000 10 

3,301 to 10,000 3 

501 to 3,300 2 

101 to 500 1 

QA/QC Measures 

In addition to standard samples, the field technicians collect equipment blanks (EB), field cleaned 

equipment blanks (FB), split samples (SS), and field duplicate samples (FD). 

Overall care must be taken in regards to equipment handling, container handling/storage, 

decontamination, and record keeping. Sample collection equipment and non-preserved sample 

containers must be rinsed three times with sample water before the actual sample is taken. Exceptions 

to this are any pre-preserved container or bac-t type samples. 

If protective gloves are used, they shall be clean, new and disposable. These should be changed upon 

arrival at a new sampling point. Highly contaminated samples shall never be placed in the same ice 

chest as environmental samples. It is good practice to enclose highly contaminated samples in a 

plastic bag before placing them in ice chests. The same is true for wastewater and drinking water 

samples. 

Ice chests or shipping containers with samples suspected of being highly contaminated shall be lined 

with new, clean, plastic bags. If possible, one member of the field team should take all the notes, fill 

out labels, etc., while the other member does all of the sampling. 

Preservation of Samples 

Proper sample preservation is the responsibility of the sampling team, not the lab providing sample 

containers. The best reference for preservatives is Standard Methods or your local laboratory. 

It is the responsibility of the field team to assure that all 

samples are appropriately preserved. 

Follow the preservative solution preparation instructions. 

Always use strong safety precautions diluting the acid. 

Put a new label on the dispensing bottle with the current 

date. 

Slowly add the acid or other preservative to the water 

sample; not water to the acid or preservative. 

Wait 3-4 hours for the preservative to cool most samples down to 4 degrees Celsius. 

Most preservatives have a shelf life of one year from the preparation date. 

When samples are analyzed for TKN, TP, NH4 and NOx 1 mL of 50% Trace Metal grade sulfuric acid 

is added to the each discrete auto sampler bottles/bags in the field lab before sampling collection. The 

preservative maintains the sample at 1.5

Troubleshooting Table for Sampling Monitoring 

Problem 

1. Positive Total Coliform. 

2. Chlorine taste and odor. 

3. Inability to maintain an adequately free chlorine 

residual at the furthest points of the distribution 

system or at dead end lines. 

Possible Cause 

1A. Improper sampling technique. 

1B. Contamination entering distribution system. 

1C. Inadequate chlorine residual at the sampling 

site. 


2A. High total chlorine residual and low free 

residual. 

3A. Inadequate chlorine dose at treatment plant. 

3B. Problems with chlorine feed equipment. 

3C. Ineffective distribution system flushing 

program. 


Possible Solution 

1A/ Check distribution system for low pressure conditions, possibly due to line breaks or excessive 

flows that may result in a backflow problem. 

1B. Insure that all staff are properly trained in sampling and transport procedures as described in the 

TCR. 

1C. Check the operation of the chlorination feed system. Refer to issues described in the sections on 

pumps and hypochlorination systems. Insure that residual test is being performed properly. 

1D. Thoroughly flush effected areas of the distribution system. Superchlorination may be necessary in 

severe cases. 

2A. The free residual should be at least 85% of the total residual. Increase the chlorine dose rate to 

get past the breakpoint in order to destroy some of the combined residual that causes taste and odor 

problems. Additional system flushing may also be required. 

3A. Increase chlorine feed rate at point of application. 

3B. Check operation of chlorination equipment. 

3C. Review distribution system flushing program and implement improvements to address areas of 

inadequate chlorine residual. 

3D. Increase flushing in area of biofilm problem. 

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150-pound chlorine gas cylinder. 

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Microbes 

Coliform bacteria are common in the environment and are generally not harmful. However, 

the presence of these bacteria in drinking water are usually a result of a problem with the 

treatment system or the pipes which distribute water, and indicates that the water may be 

contaminated with germs that can cause disease. 

Fecal Coliform and E. coli are bacteria whose presence indicates that the water may be 

contaminated with human or animal wastes. Microbes in these wastes can cause short-term 

effects, such as diarrhea, cramps, nausea, headaches, or other symptoms. 

Cryptosporidium is a parasite that enters lakes and rivers through sewage and animal 

waste. It causes cryptosporidiosis, a mild gastrointestinal disease. However, the disease can 

be severe or fatal for people with severely weakened immune systems. The EPA and CDC 

have prepared advice for those with severely compromised immune systems who are 

concerned about Cryptosporidium. 

Giardia lamblia is a parasite that enters lakes and rivers through sewage and animal waste. 

It causes gastrointestinal illness (e.g. diarrhea, vomiting, and cramps). 

Counting water fleas is just one daily task for many water treatment operators. Water 

Fleas or Daphnia are small crustaceans and great bio-indicators. Changes in heart 

rate might suggest a chemical compound has a physiological effect, and more 

importantly-Daphnia Magna is used to measure the toxicity of a chemical compound 

in water (LD50 measurements). 

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Safe Drinking Water Act (SDWA) 

On August 6, 1996, President Clinton signed the Reauthorization of the Safe Drinking 

Water Act, bringing to a successful conclusion to years of work on the part of water 

professionals and a broad range of public interest groups throughout the nation. This 

law strikes a balance among federal, state, local, urban, rural, large and small water 

systems in a manner that improves the protection of public health and brings reason 

and good science to the regulatory process. 

The major elements of this law include: 

� The law updates the standard-setting process by focusing regulations on contaminants 

known to pose greater public health risks. 

� It replaces the current law's demand for 25 new standards every three years with a new 

process based on occurrence, relative risk and cost-benefit considerations. 

� It also requires the EPA to select at least five new candidate contaminants to consider for 

regulation every five years. 

� The EPA is directed to require public water systems to provide customers with annual 

"Consumer Confidence Reports" in newspapers and by direct mail. 

� The reports must list levels of regulated contaminants along with Maximum Contaminant 

Levels (MCLs) and Maximum Contaminant Level Goals (MCLGs), along with plainly 

worded definitions of both. 

� The reports must also include a plainly worded statement of the health concerns for any 

contaminants for which there has been a violation, describe the utility's sources of 

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drinking water and provide data on unregulated contaminants for which monitoring is 

required, including Cryptosporidium and radon. 

� The EPA must establish a toll-free hot line customers can call to get additional 

information. 

� The EPA is required to publish guidelines for states to develop water source assessment 

programs that delineate protection areas and assess contamination risks. 

� The EPA is required to identify technologies that are affordable for small systems to 

comply with drinking water regulations. 

� Technical assistance funds and Small System Technical Assistance Centers are 

authorized to meet the training and technical needs of small systems. 

� States are authorized to grant variances for compliance with drinking water regulations 

for systems serving 3,300 or fewer persons. 

� The EPA is required to publish certification guidelines for operators of community and 

nontransient noncommunity public water systems. 

� States that do not have operator certification programs that meet the requirements of the 

guidelines will lose 20 percent of their SRLF grant. 

� A source water petition program for voluntary, incentive-based partnerships among public 

water systems and others to reduce contamination in source water is authorized. 

� The law establishes a new State Revolving Loan Fund (SRLF) of $1 billion per year to 

provide loans to public water systems to comply with the new SDWA. 

� It also requires states to allocate 15 percent of the SRLF to systems serving 10,000 or 

fewer people unless no eligible projects are available for loans. 

� It also allows states to jointly administer SDWA and Clean Water Act loan programs and 

transfer up to 33 percent between the two accounts. 

� States must ensure that all new systems have compliance capacity and that all current 

systems maintain capacity, or lose 20 percent of their SRLF grant. 

Although the EPA will continue to provide policy, regulations and guidance, state 

governments will now have more regulatory flexibility allowing for improved communication 

between water providers and their local regulators. Increased collaboration will result in 

solutions that work better and are more fully supported by the regulated community. States 

that have a source water assessment program may adopt alternative monitoring 

requirements to provide permanent monitoring relief for public water systems in accordance 

with EPA guidance. 

Safe Drinking Water Act of 1974 

(PL 93-523) as amended by: 

� The Safe Drinking Water Act Amendments of 1986 

� National Primary Drinking Water Regulations, 40 CFR 141 

� National Interim Primary Drinking Water Regulations Implementation, 40 CFR142 

� National Secondary Drinking Water Regulations, 40 CFR 143 

This is the primary Federal legislation protecting drinking water supplied by public water 

systems (those serving more than 25 people). The Environmental Protection Agency (EPA) 

is the lead agency and is mandated to set standards for drinking water. The EPA establishes 

national standards of which the states are responsible for enforcing. 

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The act provides for the establishment of primary regulations for the protection of the public 

health and secondary regulations relating to the taste, odor, and appearance of drinking 

water. Primary drinking water regulations, by definition, include either a maximum 

contaminant level (MCL) or, when a MCL is not economically or technologically feasible, a 

prescribed treatment technique which would prevent adverse health effects to humans. 

An MCL is the permissible level of a contaminant in water that is delivered to any user of a 

public water system. Primary and secondary drinking water regulations are stated in 40 CFR 

141 and 143, respectively. As amended in 1986, the EPA is required to set maximum 

contaminant levels for 83 contaminants deemed harmful to humans (with specific deadlines). 

It also has authority over groundwater. Water agencies are required to monitor water to 

ensure it meets standards. 

National Drinking Water Regulations 

The Act instructs the EPA on how to select contaminants for regulation and specifies how the 

EPA must establish national primary drinking water regulations once a contaminant has been 

selected (Section 1412). As of late 1996, the EPA had promulgated 84 drinking water 

regulations. 

Contaminant Selection 

P.L. 104-182 establishes a new process for the EPA to select contaminants for regulatory 

consideration based on occurrence, health effects, and meaningful opportunity for health risk 

reduction. By February 1998 and every 5 years thereafter, the EPA must publish a list of 

contaminants that may warrant regulation. Every 5 years thereafter, the EPA must determine 

whether or not to regulate at least 5 of the listed contaminants. The Act directs the EPA to 

evaluate contaminants that present the greatest health concern and to regulate contaminants 

that occur at concentration levels and frequencies of public health concern. The law also 

includes a schedule for the EPA to complete regulations for disinfectants and disinfection 

byproducts (D/DBPs) and Cryptosporidium (a waterborne pathogen). 

Standard Setting 

Developing national drinking water regulations is a two-part process. For each contaminant 

that the EPA has determined merits regulation, the EPA must set a non-enforceable 

maximum contaminant level goal (MCLG) at a level at which no known or anticipated 

adverse health effects occur, and which allows an adequate margin of safety. The EPA must 

then set an enforceable standard, a maximum contaminant level (MCL), as close to the 

MCLG as is "feasible" using the best technology, treatment techniques, or other means 

available (taking costs into consideration). 

Standards are generally based on technologies that are affordable for large communities; 

however, under P.L. 104-182, each regulation establishing an MCL must list any 

technologies, treatment techniques, or other means that comply with the MCL and that are 

affordable for three categories of small public water systems. 

The 1996 Amendments authorize the EPA to set a standard at other than the feasible level if 

the feasible level would lead to an increase in health risks by increasing the concentration of 

other contaminants or by interfering with the treatment processes used to comply with other 

SDWA regulations. In such cases, the standard or treatment techniques must minimize the 

overall health risk. 

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Also, when proposing a regulation, the EPA must now publish a determination as to whether 

or not the benefits of the standard justify the costs. If the EPA determines that the benefits do 

not justify the costs, the EPA may, with certain exceptions, promulgate a standard that 

maximizes health risk reduction benefits at a cost that is justified by the benefits. 

Risk Assessment 

P.L. 104-182 adds risk assessment and communication provisions to SDWA. When 

developing regulations, the EPA is now required to: (1) use the best available, peer-reviewed 

science and supporting studies and data; and (2) make publicly available a risk assessment 

document that discusses estimated risks, uncertainties, and studies used in the assessment. 

When proposing drinking water regulations, the EPA must publish a health risk reduction and 

cost analysis. The law permits the EPA to promulgate an interim standard without first 

preparing a benefit-cost analysis or making a determination as to whether the benefits of a 

regulation would justify the costs if the EPA determines that a contaminant presents an 

urgent threat to public health. 

New regulations generally become effective 3 years after promulgation. Up to 2 additional 

years may be allowed if the EPA (or a state in the case of an individual system) determines 

the time is needed for capital improvements. Section 1412 includes specific provisions for 

arsenic, sulfate, and radon. The law authorizes states to grant Systems variances from a 

regulation if raw water quality prevents meeting the standards despite application of the best 

technology (Section 1415). A new provision authorizes small system variances based on 

best affordable technology. States may grant these variances to systems serving 3,300 or 

fewer persons if the system cannot afford to comply (through treatment, an alternative water 

source, or restructuring) and the variance ensures adequate protection of public health; 

states may grant variances to systems serving between 3,300 and 10,000 persons with EPA 

approval. To receive a small system variance, the system must install a variance technology 

identified by the EPA. The variance technology need not meet the MCL, but must protect 

public health. The EPA must identify variance technologies for existing regulations. 

Variances are not available for microbial contaminants. The Act also provides for exemptions 

if a regulation cannot be met for other compelling reasons (including costs) and if the system 

was in operation before the effective date of a standard or treatment requirement (Section 

1416). An exemption is intended to give a public water system more time to comply with a 

regulation and can be issued only if it will not result in an unreasonable health risk. Small 

systems may receive exemptions for up to 9 years. 

State Primacy 

The primary enforcement responsibility for public water systems lies with the states, provided 

they adopt regulations as stringent as the national requirements, adopt authority for 

administrative penalties, develop adequate procedures for enforcement, maintain records, 

and create a plan for providing emergency water supplies (Section 1413). Currently, 55 of 

57 states and territories have primacy authority. P.L. 104-182 authorizes $100 million 

annually for EPA to make grants to states to carry out the public water system supervision 

program. States may also use a portion of their SRF grant for this purpose (Section 1443). 

Whenever the EPA finds that a public water system in a state with primary enforcement 

authority does not comply with regulations, the Agency must notify the state and the system 

and provide assistance to bring the system into compliance. If the state fails to commence 

enforcement action within 30 days after the notification, the EPA is authorized to issue an 

administrative order or commence a civil action. 

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Nonprimacy State 

In a non-primacy state, the EPA must notify an elected local official (if any has jurisdiction 

over the water system) before commencing an enforcement action against the system 

(Section 1414). Primacy states may establish alternative monitoring requirements to provide 

interim monitoring relief for systems serving 10,000 or fewer persons for most contaminants, 

if a contaminant is not detected in the first quarterly sample. States with approved source 

water protection programs may adopt alternative monitoring requirements to provide 

permanent monitoring relief to qualified systems for chemical contaminants (Section 1418). 

P.L. 104-182 requires states to adopt programs for training and certifying operators of 

community and nontransient noncommunity systems. The EPA must publish guidelines 

specifying minimum standards for operator certification by February 1999. Two years 

thereafter, the EPA must withhold 20% of a state's SRF grant unless the state has an 

operator certification program (Section 1419). States are also required to establish capacity 

development programs based on EPA guidance. 

State programs must include: 1) legal authority to ensure that new systems have the 

technical, financial, and managerial capacity to meet SDWA requirements; and 2) a strategy 

to assist existing systems that are experiencing difficulties to come into compliance. 

Beginning in 2001, the EPA is required to withhold a portion of SRF grants from states that 

do not have compliance development strategies (Section 1420). 

Underground Injection Control 

Another provision of the Act requires the EPA to promulgate regulations for state 

underground injection control (UIC) programs to protect underground sources of drinking 

water. These regulations contain minimum requirements for the underground injection of 

wastes in five well classes to protect underground sources of drinking water and to require 

that a state prohibit, by December 1977, any underground injection that was not authorized 

by state permit (Section 1421). 

Ground Water Protection Grant Programs 

The Act contains three additional ground water protection programs. Added in 1986, Section 

1427 established procedures for demonstration programs to develop, implement, and assess 

critical aquifer protection areas already designated by the Administrator as sole source 

aquifers. Section 1428, also added in 1986, and established an elective state program for 

protecting wellhead areas around public water system wells. 

If a state established a wellhead protection program by 1989, and the EPA approved the 

state's program, then the EPA may award grants covering between 50% and 90% of the 

costs of implementing the program. Section 1429, added by P.L. 104-182, authorizes the 

EPA to make 50% grants to states to develop programs to ensure coordinated and 

comprehensive protection of ground water within the states. Appropriations for these three 

programs and for LYIC state program grants are authorized starting back in FY2003. 

Source Water Protection Programs 

P.L. 104-182 broadens the pollution prevention focus of the Act to embrace surface water as 

well as ground water protection. New Section 1453 directs the EPA to publish guidance for 

states to implement source water assessment programs that delineate boundaries of 

assessment areas from which systems receive their water, and identify the origins of 

contaminants in delineated areas to determine systems' susceptibility to contamination. 

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States with approved assessment programs may adopt alternative monitoring requirements 

to provide systems with monitoring relief under Section 1418. 

New Section 1454 authorizes a source water petition program based on voluntary 

partnerships between state and local governments. States may establish a program under 

which a community water system or local government may submit a source water quality 

partnership petition to the state requesting assistance in developing a voluntary partnership 

to: (1) reduce the presence of contaminants in drinking water; (2) receive financial or 

technical assistance; and (3) develop a long-term source water protection strategy. This 

section authorizes $5 million each year for grants to states to support petition programs. 

Also, states may use up to 10% of their annual SRF capitalization grant for the source water 

assessment activities or for the petition program. 

State Revolving Funds 

Section 1452, added by P.L. 104-182 authorizes a State Revolving Loan Fund (SRF) 

program to help systems finance improvements needed to comply with drinking water 

regulations. The law authorizes the EPA to make grants to states to capitalize SDWA SRFs, 

which states then use to make loans to public water systems. States must match 20% of the 

federal grant. 

Grants will be allotted to states using the formula for distributing state PWSS grants through 

FY1997; then, grants will be allotted based on a needs survey. Each state will receive at 

least 1% of funds. The District of Columbia will receive 1% of funds as well. A state may 

transfer up to 33% of the grant to the Clean Water Act (CWA) SRF, or an equivalent amount 

from the CWA SRF to the SDWA SRF. 

Drinking water SRFs may be used to provide loan 

and grant assistance for expenditures that the EPA 

has determined will facilitate compliance or 

significantly further the Act's health protection 

objectives. States must make available 15% of their 

annual allotment for loan assistance to systems 

that serve 10,000 or fewer persons. States may 

use up to 30% of their SRF grant to provide grants 

or forgive loan principle to help economically 

disadvantaged communities. Also, states may use 

a portion of funds for technical assistance, source 

water protection and capacity development 

programs, and for operator certification. 

Other Provisions 

Public water systems must notify customers of violations with potential for serious health 

effects within 24 hours. Systems must also issue to customers annual reports on 

contaminants detected in their drinking water (Section 1414). Section 1417 requires any 

pipe, solder, or flux used in the installation or repair of public water systems or of plumbing in 

residential or nonresidential facilities providing drinking water to be "lead free" (as defined in 

the Act). As of August 1998, it will be unlawful to sell pipes, plumbing fittings or fixtures that 

are not "lead free" or to sell solder or flux that is not lead free(unless it is properly labeled); 

with the exception of pipes used in manufacturing or industrial processing. P.L. 104-182 sets 

limits on the amount of lead that may leach from new plumbing fixtures, and allows one year 

for a voluntary standard to be established before requiring EPA to take regulatory action. 

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The Administrator has emergency powers to issue orders and commence civil action if a 

contaminant likely to enter a public drinking water supply system poses a substantial threat 

to public health and state or local officials have not taken adequate action(Section 1431). 

If a chemical necessary for water treatment is not reasonably available, the Administrator can 

issue a "certification of need," in which case the President can order an allocation of the 

chemical to those needing it (Section 1441). 

EPA is provided authority to conduct research, studies, and demonstrations related to the 

causes, treatment, control, and prevention of diseases resulting from contaminants in water. 

The Agency is directed to provide technical assistance to the states and municipalities in 

administering their public water system regulatory responsibilities. The law authorizes 

annually, $15 million for technical assistance to small systems and Indian Tribes, and $25 

million for health effects research (Section 1442). P.L. 104-182 authorizes additional 

appropriations for drinking water research, not to exceed $26.6 million annually. 

The Administrator may make grants to develop and demonstrate new technologies for 

providing safe drinking water and to investigate health implications involved in the 

reclamation/reuse of waste waters (Section 1444). 

Also, suppliers of water who may be subject to regulation under the Act are required to 

establish and maintain records, monitor, and provide any information that the Administrator 

requires to carry out the requirements of the Act (Section 1445). 

The Administrator may also enter and inspect the property of water suppliers to enable 

him/her to carry out the purposes of the Act. Failure to comply with these provisions may 

result in criminal penalties. 

The Act established a National Drinking Water Advisory Council, composed of 15 members 

(with at least 2 representing rural systems), to advise, consult, and make recommendations 

to the Administrator on activities and policies derived from the Act (Section 1446). 

National Security 

Any federal agency having jurisdiction over federally owned and maintained public water 

systems must comply with all federal, state, and local drinking water requirements, as well as 

any underground injection control programs (Section 1447). The Act provides for waivers in 

the interest of national security. Procedures for judicial review are outlined (Section 1448), 

and provision for citizens' civil actions is made (Section 1449). 

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Water Quality Key Words 

Activated alumina: It is manufactured from aluminum hydroxide by dehydroxylating it in a 

way that produces a highly porous material; this material can have a surface area 

significantly over 200 square meters/g. The compound is used as a desiccant (to keep things 

dry by absorbing water from the air) and as a filter of fluoride, arsenic and selenium in 

drinking water. It is made of aluminum oxide (alumina; Al2O3), the same chemical substance 

as sapphire and rubies (but without the impurities that give those gems their color). It has a 

very high surface-area-to-weight ratio. That means it has a lot of very small pores, almost like 

tunnels, that run throughout it. 

Activated carbon: It is also called activated charcoal or activated coal, is a form of carbon 

that has been processed to make it extremely porous and thus to have a very large surface 

area available for adsorption or chemical reactions. The word activated in the name is 

sometimes substituted by active. Due to its high degree of microporosity, just one gram of 

activated carbon has a surface area of approximately 500 m², as determined typically by 

nitrogen gas adsorption. Sufficient activation for useful applications may come solely from 

the high surface area, though further chemical treatment often enhances the adsorbing 

properties of the material. Activated carbon is usually derived from charcoal. 

De-ionized: Water with the irons removed. 

Dissolved organic carbon: Dissolved organic carbon (DOC) is a broad classification for 

organic molecules of varied origin and composition within aquatic systems. The "dissolved" 

fraction of organic carbon is an operational classification. Many researchers place the 

dissolved/colloidal cutoff at 0.45 micrometers, but 0.22 micrometers is also typical. 

Ethylenediaminetetraacetic acid (EDTA): EDTA is a widely used abbreviation for the 

chemical compound ethylenediaminetetraacetic acid (and many other names, see table). 

EDTA refers to the chelating agent with the formula (HO2CCH2)2NCH2CH2N(CH2CO2H)2. This 

amino acid is widely used to sequester di- and trivalent metal ions (Ca 2+ and Mg 2+ for 

example). EDTA binds to metals via four carboxylate and two amine groups. EDTA forms 

especially strong complexes with Mn(II), Cu(II), Fe(III), Pb (II) and Co(III). 

High temperature metals recovery: An improved method and apparatus for recovering 

metal values from Electric Arc Furnace dust, particularly zinc and iron values, by mixing EAF 

dust and carbonaceous fines to form a particulate mixture; heating the mixture at a sufficient 

temperature and for a sufficient time to reduce and release volatile metals and alkali metals 

in a flue gas; collecting the released metals, and removing the metal values from the process 

as product. 

Microfiltration: A low pressure membrane filtration process that removes suspended solids 

and colloids generally larger than 0.1 micron diameter. 

Nanofiltration: It is a relatively recent membrane process used most often with low total 

dissolved solids water such as surface water and fresh groundwater, with the purpose of 

softening (polyvalent cation removal) and removal of disinfection by-product precursors such 

as natural organic matter and synthetic organic matter. 

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SDWA Water Quality 

Information and MCLs 

Radionuclides 

Alpha Emitters Certain minerals are radioactive and may emit a form of radiation known as 

alpha radiation. Some people who drink water containing alpha emitters in excess of EPA 

standards over many years may have an increased risk of getting cancer. 

Beta/photon Emitters Certain minerals are radioactive and may emit forms of radiation 

known as photons and beta radiation. Some people who drink water containing beta and 

photon emitters in excess of EPA standards over many years may have an increased risk of 

getting cancer. 

Combined Radium 226/228 Some people who drink water containing radium 226 or 228 in 

excess of EPA standards over many years may have an increased risk of getting cancer. 

Radon gas can dissolve and accumulate in underground water sources, such as wells, and 

in the air in your home. Breathing radon can cause lung cancer. Drinking water containing 

radon presents a risk of developing cancer. Radon in air is more dangerous than radon in 

water. 

These are commonly found examples of various water sampling bottles. VOC and 

THM bottles are in the front. You have to make sure there is absolutely no air inside 

these tiny bottles. Any air bubble can ruin the sample. There are several ways to get 

the air out. The best one is slowly overfill the bottle to get a reverse meniscus. 

Second, is to fill the cap with water before screwing it onto the bottle. The third one is 

to use a thin copper tube and slowly fill the bottle. 

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Inorganic Contaminants 

Antimony 

Asbestos 

Barium 

Beryllium 

Cadmium 

Chromium 

Copper 

Cyanide 

Mercury 

Nitrate 

Nitrite 

Selenium 

Thallium 

Inorganic Contaminants 

Arsenic. Some people who drink water containing arsenic in excess of EPA standards over many 

years could experience skin damage or problems with their circulatory system, and may have an 


Fluoride. Many communities add fluoride to their drinking water to promote dental health. Each 

community makes its own decision about whether or not to add fluoride. The EPA has set an 

enforceable drinking water standard for fluoride of 4 mg/L (some people who drink water containing 

fluoride in excess of this level over many years could get bone disease, including pain and tenderness 

of the bones). The EPA has also set a secondary fluoride standard of 2 mg/L to protect against dental 

fluorosis. 

Dental fluorosis, in its moderate or severe forms, may result in a brown staining and/or pitting of the 

permanent teeth. This problem occurs only in developing teeth, before they erupt from the gums. 

Children under nine should not drink water that has more than 2 mg/L of fluoride. 

Lead. Typically leaches into water from plumbing in older buildings. Lead pipes and plumbing fittings 

have been banned since August 1998. Children and pregnant women are most susceptible to lead 

health risks. For advice on avoiding lead, see the EPA’s “Lead in Your Drinking Water” fact sheet. 

Synthetic Organic Contaminants, including Pesticides & Herbicides 

2,4-D 

2,4,5-TP (Silvex) 

Acrylamide 

Alachlor 

Atrazine 

Benzoapyrene 

Carbofuran 

Chlordane 

Dalapon 

Di 2-ethylhexyl adipate 

Di 2-ethylhexyl phthalate 

Dibromochloropropane 

Dinoseb 

Dioxin (2,3,7,8-TCDD) 

Diquat 

Endothall 

Endrin 

Epichlorohydrin 

Ethylene dibromide 

Glyphosate 

Heptachlor 

Heptachlor epoxide 

Volatile Organic Contaminants 

Benzene 

trans-1,2-Dicholoroethylene 

Carbon Tetrachloride 

Dichloromethane 

Chlorobenzene 

1,2-Dichloroethane 

o-Dichlorobenzene 

1,2-Dichloropropane 

p-Dichlorobenzene 

Ethylbenzene 

1,1-Dichloroethylene 

Styrene 

cis-1,2-Dichloroethylene Tetrachloroethylene 

Hexachlorobenzene 

Hexachlorocyclopentadiene 

Lindane 

Methoxychlor 

Oxamyl [Vydate] 

PCBs [Polychlorinated biphenyls] 

Pentachlorophenol 

Picloram 

Simazine 

Toxaphene 

1,2,4-Trichlorobenzene 

1,1,1,-Trichloroethane 

1,1,2-Trichloroethane 

Trichloroethylene 

Toluene 

Vinyl Chloride 

Xylenes 

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New EPA Water Rules 

Arsenic 

Arsenic is a chemical that occurs naturally in the earth's crust. When rocks, minerals, and soil 

erode, they release arsenic into water supplies. When people either drink this water or eat 

animals and plants that drink it, they are exposed to arsenic. In the U.S., eating and drinking 

are the most common ways that people are exposed to arsenic, although it can also come 

from industrial sources. Studies have linked long-term exposure of arsenic in drinking water 

to a variety of cancers in humans. 

To protect human health, an EPA standard limits the amount of arsenic in drinking water. 

Back in January 2001, the EPA revised the standard from 50 parts per billion (ppb), ordering 

that it fall to 10 ppb back in 2006. After adopting 10ppb as the new standard for arsenic in 

drinking water, the EPA decided to review the decision to ensure that the final standard was 

based on sound science and accurate estimates of costs and benefits. In October 2001, the 

EPA decided to move forward with implementing the 10ppb standard for arsenic in drinking 

water. 

More information on the rulemaking process and the costs and benefits of setting the arsenic 

limit in drinking water at 10ppb can be found at www.epa.gov/safewater/arsenic.html or in the 

Water Quality Chapter in the Arsenic information section. 

ICR Information Collection Rule 

The EPA has collected data required by the Information Collection Rule (ICR) to support 

future regulation of microbial contaminants, disinfectants, and disinfection byproducts. The 

rule is intended to provide the EPA with information on chemical byproducts that form when 

disinfectants used for microbial control react with chemicals already present in source water 

(disinfection byproducts (DBPs)); disease-causing microorganisms (pathogens), including 

Cryptosporidium; and engineering data to control these contaminants. 

Drinking water microbial and disinfection byproduct information collected for the ICR is now 

available in the EPA's Envirofacts Warehouse. 

Gas Chromatograph 

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Disinfection Byproduct Regulations 

In December 1998, the EPA established the Stage 1 Disinfectants/Disinfection Byproducts 

Rule that requires public water systems to use treatment measures to reduce the formation 

of disinfection byproducts and to meet the following specific standards: 

Total 

trihalomethanes 80 parts per billion (ppb) 

(TTHM) 

Haloacetic 

60 ppb 

acids (HAA5) 

Bromate 10 ppb 

Chlorite 1.0 parts per million (ppm) 

Currently trihalomethanes are regulated at a maximum allowable annual average level of 100 

parts per billion for water systems serving over 10,000 people under the Total 

Trihalomethane Rule finalized by the EPA in 1979. The Stage 1 Disinfectant/Disinfection 

Byproduct Rule standards became effective for trihalomethanes and other disinfection 

byproducts listed above in December 2001 for large surface water public water systems. 

These new standards became effective in December 2003 for small surface water and all 

ground water public water systems. 

Disinfection byproducts are formed when disinfectants used in water treatment plants 

react with bromide and/or natural organic matter (i.e., decaying vegetation) present in the 

source water. Different disinfectants produce different types or amounts of disinfection 

byproducts. Disinfection byproducts for which regulations have been established have been 

identified in drinking water, including trihalomethanes, haloacetic acids, bromate, and 

chlorite. 

Trihalomethanes (THM) are a group of four chemicals that are formed along with other 

disinfection byproducts when chlorine or other disinfectants used to control microbial 

contaminants in drinking water react with naturally occurring organic and inorganic matter in 

water. The trihalomethanes are chloroform, bromodichloromethane, dibromochloromethane, 

and bromoform. The EPA has published the Stage 1 Disinfectants/Disinfection 

Byproducts Rule to regulate total trihalomethanes (TTHM) at a maximum allowable annual 

average level of 80 parts per billion. 

Haloacetic Acids (HAA5) are a group of chemicals that are formed along with other 

disinfection byproducts when chlorine or other disinfectants used to control microbial 

contaminants in drinking water react with naturally occurring organic and inorganic matter in 

water. The regulated haloacetic acids, known as HAA5, are: monochloroacetic acid, 

dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid. The 

EPA has published the Stage 1 Disinfectants/Disinfection Byproducts Rule to regulate 

HAA5 at 60 parts per billion annual average. 

Bromate is a chemical that is formed when ozone used to disinfect drinking water reacts with 

naturally occurring bromide found in source water. The EPA has established the Stage 1 

Disinfectants/Disinfection Byproducts Rule to regulate bromate at annual average of 10 

parts per billion in drinking water. 

Chlorite is a byproduct formed when chlorine dioxide is used to disinfect water. The EPA 

has published the Stage 1 Disinfectants/Disinfection Byproducts Rule to regulate chlorite 

at a monthly average level of 1 part per million in drinking water. 

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Microbial Regulations 

One of the key regulations developed and implemented by the United States Environmental 

Protection Agency (USEPA) to counter pathogens in drinking water is the Surface Water 

Treatment Rule. Among its provisions, the rule requires that a public water system, using 

surface water (or ground water under the direct influence of surface water) as its source, 

have sufficient treatment to reduce the source water concentration of Giardia and viruses by 

at least 99.9% and 99.99%, respectively. 

The Surface Water Treatment Rule specifies treatment criteria to assure that these 

performance requirements are met; they include turbidity limits, disinfectant residual, and 

disinfectant contact time conditions. 

The Interim Enhanced Surface Water Treatment Rule was established in December 1998 

to control Cryptosporidium, and to maintain control of pathogens while systems lower 

disinfection byproduct levels to comply with the Stage 1 Disinfectants/Disinfection 

Byproducts Rule. The EPA established a Maximum Contaminant Level Goal (MCLG) of 

zero for all public water systems and a 99% removal requirement for Cryptosporidium in 

filtered public water systems that serve at least 10,000 people. 

The new rule tightened turbidity standards back in December 2001. Turbidity is an indicator 

of the physical removal of particulates, including pathogens. 

The EPA is also planning to develop other rules to further control pathogens. The EPA has 

promulgated a Long Term 1 Enhanced Surface Water Treatment Rule, for systems serving 

fewer than 10,000 people, to improve physical removal of Cryptosporidium, and to maintain 

control of pathogens while systems comply with Stage 1 Disinfectants/Disinfection 

Byproducts Rule. 

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Here is one of TLC’s professors Marcos Aparecido Silva Bueno showing microscopic 

views of commonly found MO’s in a classroom setting. Professor Marcos Aparecido 

Silva Bueno is a world renowned microbiological expert. 

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National Primary Drinking Water Regulations 

Inorganic 

Chemicals 

MCLG 

1 

(mg/L) 

4 

MCL 2 

or TT 3 

(mg/L) 

4 

Potential Health 

Effects from 

Ingestion of Water 

Antimony 0.006 0.006 Increase in blood cholesterol; 

decrease in blood glucose 

Arsenic none 5 0.010 Skin damage; circulatory 

system problems; increased 

risk of cancer 

Asbestos 

(fiber >10 

micrometers) 

7 million 

fibers per 

Liter 

7 MFL Increased risk of developing 

benign intestinal polyps 

Sources of 

Contaminant in 

Drinking Water 

Discharge from petroleum 

refineries; fire retardants; 

ceramics; electronics; solder 

Discharge from semiconductor 

manufacturing; petroleum 

refining; wood preservatives; 

animal feed additives; 

herbicides; erosion of natural 

deposits 

Decay of asbestos cement in 

water mains; erosion of natural 

deposits 

Barium 2 2 Increase in blood pressure Discharge of drilling wastes; 

discharge from metal refineries; 

erosion of natural deposits 

Beryllium 0.004 0.004 Intestinal lesions Discharge from metal refineries 

and coal-burning factories; 

discharge from electrical, 

aerospace, and defense 

industries 

Cadmium 0.005 0.005 Kidney damage Corrosion of galvanized pipes; 

erosion of natural deposits; 

discharge from metal refineries; 

runoff from waste batteries and 

Chromium (total) 0.1 0.1 Some people who use water 

containing chromium well in 

excess of the MCL over many 

years could experience allergic 

Copper 1.3 Action 

Level=1. 

3; TT 6 

Cyanide (as free 

cyanide) 

dermatitis 

Short term exposure: 

Gastrointestinal distress. 

Long term exposure: Liver or 

kidney damage. Those with 

Wilson's Disease should 

consult their personal doctor if 

their water systems exceed the 

copper action level. 

0.2 0.2 Nerve damage or thyroid 

problems 

Fluoride 4.0 4.0 Bone disease (pain and 

tenderness of the bones); 

Children may get mottled 

Lead zero Action 

Level=0. 

015; TT 6 

teeth. 

Infants and children: Delays in 

physical or mental 

development. 

Adults: Kidney problems; high 

blood pressure 

paints 

Discharge from steel and pulp 

mills; erosion of natural 

deposits 

Corrosion of household 

plumbing systems; erosion of 

natural deposits; leaching from 

wood preservatives 

Discharge from steel/metal 

factories; discharge from plastic 

and fertilizer factories 

Water additive which promotes 

strong teeth; erosion of natural 

deposits; discharge from 

fertilizer and aluminum factories 

Corrosion of household 

plumbing systems; erosion of 

natural deposits 

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Inorganic Mercury 0.002 0.002 Kidney damage Erosion of natural deposits; 

discharge from refineries and 

factories; runoff from landfills 

and cropland 

Nitrate (measured 

as Nitrogen) 

Nitrite (measured as 

Nitrogen) 

10 10 "Blue baby syndrome" in 

infants under six months - life 

threatening without immediate 

medical attention. 

Symptoms: Infant looks blue 

and has shortness of breath. 

1 1 "Blue baby syndrome" in 

infants under six months - life 

threatening without immediate 

medical attention. 

Symptoms: Infant looks blue 

and has shortness of breath. 

Selenium 0.05 0.05 Hair or fingernail loss; 

numbness in fingers or toes; 

circulatory problems 

Thallium 0.0005 0.002 Hair loss; changes in blood; 

kidney, intestine, or liver 

problems 

Runoff from fertilizer use; 

leaching from septic tanks, 

sewage; erosion of natural 

deposits 

Runoff from fertilizer use; 

leaching from septic tanks, 

sewage; erosion of natural 

deposits 


refineries; erosion of natural 

deposits; discharge from mines 

Leaching from ore-processing 

sites; discharge from 

electronics, glass, and 

pharmaceutical companies 

1-ton chlorine gas container with an automatic leak detection and shut-off device. 

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Organic 

Chemicals 

MCLG 

1 

(mg/L) 

4 

MCL 2 

or TT 3 

(mg/L) 

4 


Effects from 


Acrylamide zero TT 7 Nervous system or blood 

problems; increased risk of 

cancer 

Alachlor zero 0.002 Eye, liver, kidney or spleen 

problems; anemia; increased 

risk of cancer 

Atrazine 0.003 0.003 Cardiovascular system 

problems; reproductive 

difficulties 

Benzene zero 0.005 Anemia; decrease in blood 

platelets; increased risk of 

cancer 

Benzo(a)pyrene zero 0.0002 Reproductive difficulties; 

increased risk of cancer 

Carbofuran 0.04 0.04 Problems with blood or 

nervous system; reproductive 

Carbon 

zero .005 

difficulties. 

Liver problems; increased risk 

Sources of 



Added to water during 

sewage/wastewater treatment 

Runoff from herbicide used on 

row crops 

Runoff from herbicide used on 

row crops 

Discharge from factories; 

leaching from gas storage tanks 

and landfills 

Leaching from linings of water 

storage tanks and distribution 

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lines 

Leaching of soil fumigant used 

on rice and alfalfa 

tetrachloride 

Chlordane zero 0.002 

of cancer 

Liver or nervous system 


Discharge from chemical plants 

and other industrial activities 

Residue of banned termiticide 

Chlorobenzene 0.1 0.1 

cancer 

Liver or kidney problems Discharger from chemical and 

2,4-D 0.07 

Dalapon 0.2 

1,2-Dibromo-3- zero 

chloropropane 

(DBCP) 

o-Dichlorobenzene 0.6 

p-Dichlorobenzene 0.075 

1,2-Dichloroethane zero 

1-1- 

0.007 

Dichloroethylene 

cis-1, 2- 

0.07 


trans-1,2- 

0.1 


Dichloromethane zero 

1-2- 

zero 

Dichloropropane 

Di(2- 

0.4 

ethylhexyl)adipateDi(2- 

zero 

ethylhexyl)phthalate 

0.07 

0.2 

0.0002 

0.6 

0.075 

0.005 

0.007 

0.07 

0.1 

0.005 

0.005 

0.4 

0.006 

agricultural chemical factories 

Kidney, liver, or adrenal gland Runoff from herbicide used on 

problems 

row crops 

Minor kidney changes Runoff from herbicide used on 

rights of way 

Reproductive difficulties; Runoff/leaching from soil 

increased risk of cancer fumigant used on soybeans, 

cotton, pineapples, and 

orchards 

Liver, kidney, or circulatory Discharge from industrial 

system problems 

chemical factories 

Anemia; liver, kidney or spleen Discharge from industrial 

damage; changes in blood chemical factories 

Increased risk of cancer Discharge from industrial 


Liver problems Discharge from industrial 






Liver problems; increased risk Discharge from pharmaceutical 

of cancer 

and chemical factories 

Increased risk of cancer Discharge from industrial 


General toxic effects or Leaching from PVC plumbing 

reproductive difficulties systems; discharge from 


Reproductive difficulties; liver Discharge from rubber and 

problems; increased risk of chemical factories 

Dinoseb 0.007 0.007 

cancer 

Reproductive difficulties Runoff from herbicide used on 

soybeans and vegetables

Dioxin (2,3,7,8- 

TCDD) 

zero 0.000000 

03 

Reproductive difficulties; 


Emissions from waste 

incineration and other 

combustion; discharge from 


Diquat 

Endothall 

0.02 

0.1 

0.02 

0.1 

Cataracts 

Stomach and intestinal 

Runoff from herbicide use 

Runoff from herbicide use 

Endrin 

Epichlorohydrin 

0.002 

zero 

0.002 

TT 

problems 

Nervous system effects Residue of banned insecticide 

7 Stomach problems; 

Discharge from industrial 

reproductive difficulties; chemical factories; added to 

Ethylbenzene 0.7 

Ethelyne dibromide zero 

0.7 

0.00005 


Liver or kidney problems 

Stomach problems; 

reproductive difficulties; 

water during treatment process 


refineries 


refineries 

Glyphosate 0.7 0.7 


Kidney problems; reproductive Runoff from herbicide use 

Heptachlor zero 0.0004 

difficulties 

Liver damage; increased risk Residue of banned termiticide 

Heptachlor epoxide zero 0.0002 

of cancer 

Liver damage; increased risk Breakdown of hepatachlor 

Hexachlorobenzene zero 0.001 

of cancer 

Liver or kidney problems; Discharge from metal refineries 

Hexachlorocyclopen 

tadiene 

Lindane 

0.05 

0.0002 

0.05 

0.0002 

reproductive difficulties; 


Kidney or stomach problems 

Liver or kidney problems 

and agricultural chemical 

factories 

Discharge from chemical 

factories 

Runoff/leaching from insecticide 

Methoxychlor 0.04 0.04 Reproductive difficulties 

used on cattle, lumber, gardens 


Oxamyl (Vydate) 0.2 0.2 Slight nervous system effects 

used on fruits, vegetables, 

alfalfa, livestock 


Polychlorinated 

biphenyls (PCBs) 

zero 0.0005 Skin changes; thymus gland 

problems; immune 

deficiencies; reproductive or 

nervous system difficulties; 

used on apples, potatoes, and 

tomatoes 

Runoff from landfills; discharge 

of waste chemicals 

Pentachlorophenol zero 

Picloram 0.5 

Simazine 0.004 

Styrene 0.1 

0.001 

0.5 

0.004 

0.1 


Liver or kidney problems; 


Liver problems 

Problems with blood 

Liver, kidney, and circulatory 

problems 

Discharge from wood 

preserving factories 

Herbicide runoff 

Herbicide runoff 

Discharge from rubber and 

plastic factories; leaching from 

Tetrachloroethylene zero 

Toluene 1 

Total 

none 

Trihalomethanes 

(TTHMs) 

0.005 

1 


of cancer 

Nervous system, kidney, or 

liver problems 

landfills 

Discharge from factories and 

dry cleaners 


factories 

5 Toxaphene zero 

0.10 

0.003 

Liver, kidney or central 

nervous system problems; 


Kidney, liver, or thyroid 


Byproduct of drinking water 

disinfection 


used on cotton and cattle 

2,4,5-TP (Silvex) 

1,2,4- 

Trichlorobenzene 

0.05 

0.07 

0.05 

0.07 

cancer 

Liver problems 

Changes in adrenal glands 

Residue of banned herbicide 

Discharge from textile finishing 

factories 

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1,1,1- 

Trichloroethane 

0.20 0.2 Liver, nervous system, or 

circulatory problems 

Discharge from metal 

degreasing sites and other 

factories 

Discharge from industrial 

1,1,2- 

Trichloroethane 

Trichloroethylene 

Vinyl chloride 

0.003 

zero 

zero 

0.005 

0.005 

0.002 

Liver, kidney, or immune 

system problems 


of cancer 

Increased risk of cancer 



refineries 

Leaching from PVC pipes; 

Xylenes (total) 10 10 Nervous system damage 

discharge from plastic factories 


factories; discharge from 


Radionuclides 

Beta particles and 

photon emitters 

Gross alpha particle 

activity 

Radium 226 and 

Radium 228 

(combined) 

Microorganisms 

MCLG 

1 

(mg/L) 

4 

MCL 2 

or TT 3 

(mg/L) 

4 

none 5 4 

millirems 

per year 


Effects from 


Sources of 



Increased risk of cancer Decay of natural and manmade 

deposits 

none 5 15 

picocurie 

s per 

Liter 

Increased risk of cancer Erosion of natural deposits 

none 

(pCi/L) 

5 5 pCi/L Increased risk of cancer Erosion of natural deposits 

MCLG 

1 

(mg/L) 

4 

MCL 2 

or TT 3 

(mg/L) 

4 


Effects from 


Sources of 



Giardia lamblia zero TT 8 Giardiasis, a gastroenteric Human and animal fecal waste 

Heterotrophic plate 

count 

N/A TT 

disease 

8 HPC has no health effects, but 

can indicate how effective 

treatment is at controlling 

n/a 

Legionella zero TT 

microorganisms. 

8 Legionnaire's Disease, 

commonly known as 

Found naturally in water; 

multiplies in heating systems 

Total Coliforms zero 5.0% 

pneumonia 

(including fecal 

coliform and E. Coli) 

9 

Used as an indicator that other 

potentially harmful bacteria 

may be present 10 

Human and animal fecal waste 

Turbidity N/A TT 8 Turbidity has no health effects 

but can interfere with 

disinfection and provide a 

medium for microbial growth. It 

may indicate the presence of 

Soil runoff 

Viruses (enteric) zero TT 

microbes. 

8 Gastroenteric disease Human and animal fecal waste 

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E. coli HO-157 

Legionella 


I’ve met lab personnel who couldn’t tell these 3 bugs apart. 

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National Secondary Drinking Water Regulations 

National Secondary Drinking Water Regulations (NSDWRs or secondary standards 

are non-enforceable guidelines regulating contaminants that may cause cosmetic 

effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or 

color) in drinking water. 

The EPA recommends secondary standards to water systems but does not require 

systems to comply. However, states may choose to adopt them as enforceable 

standards. 

Contaminant 

Secondary Standard 

Aluminum 0.05 to 0.2 mg/L 

Chloride 250 mg/L 

Color 15 (color units) 

Copper 1.0 mg/L 

Corrosivity noncorrosive 

Fluoride 2.0 mg/L 

Foaming Agents 0.5 mg/L 

Iron 0.3 mg/L 

Manganese 0.05 mg/L 

Odor 3 threshold odor number 

pH 6.5-8.5 

Silver 0.10 mg/L 

Sulfate 250 mg/L 

Total Dissolved Solids 500 mg/L 

Zinc 5 mg/L 

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Notes 

1 Maximum Contaminant Level Goal (MCLG) - The maximum level of a contaminant in 

drinking water at which no known or anticipated adverse effect on the health effect of 

persons would occur, and which allows for an proper margin of safety. MCLGs are 

non-enforceable public health goals. 

2 Maximum Contaminant Level (MCL) - The maximum permissible level of a 

contaminant in water which is delivered to any user of a public water system. MCLs 

are enforceable standards. The margins of safety in MCLGs ensure that exceeding the 

MCL slightly does not pose significant risk to public health. 

3 Treatment Technique - An enforceable procedure or level of technical performance 

which public water systems must follow to ensure control of a contaminant. 

4 Units are in milligrams per Liter (mg/L) unless otherwise noted. 

5 MCLGs were not established before the 1986 Amendments to the Safe Drinking 

Water Act. Therefore, there is no MCLG for this contaminant. 

6 Lead and copper are regulated in a Treatment Technique which requires systems to 

take tap water samples at sites with lead pipes or copper pipes that have lead solder 

and/or are served by lead service lines. The action level, which triggers water systems 

into taking treatment steps, if exceeded in more than 10% of tap water samples, for 

copper is 1.3 mg/L, and for lead is 0.015mg/L. 

7 Each water system must certify, in writing, to the state (using third-party or 

manufacturer's certification) that when acrylamide and epichlorohydrin are used in 

drinking water systems, the combination (or product) of dose and monomer level does 

not exceed the levels specified, as follows: 

� Acrylamide = 0.05% dosed at 1 mg/L (or equivalent) 

� Epichlorohydrin = 0.01% dosed at 20 mg/L (or equivalent) 

8 The Surface Water Treatment Rule requires systems using surface water or ground 

water under the direct influence of surface water to (1) disinfect their water, and (2) 

filter their water or meet criteria for avoiding filtration so that the following 

contaminants are controlled at the following levels: 

� Giardia lamblia: 99.9% killed/inactivated 

Viruses: 99.99% killed/inactivated 

� Legionella: No limit, but EPA believes that if Giardia and viruses are 

inactivated, Legionella will also be controlled. 

� Turbidity: At no time can turbidity (cloudiness of water) go above 5 

nephelolometric turbidity units (NTU); systems that filter must ensure that the 

turbidity go no higher than 1 NTU (0.5 NTU for conventional or direct filtration) 

in at least 95% of the daily samples in any month. 

� HPC: NO more than 500 bacterial colonies per milliliter. 

9 No more than 5.0% samples total coliform-positive in a month. (For water systems 

that collect fewer than 40 routine samples per month, no more than one sample can 

be total coliform-positive). Every sample that has total coliforms must be analyzed for 

fecal coliforms. There cannot be any fecal coliforms. 

10 Fecal coliform and E. coli are bacteria whose presence indicates that the water may 

be contaminated with human animal wastes. Microbes in these wastes can cause 

diarrhea, cramps, nausea, headaches, or other symptoms. 

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Chlorine Section 

1-ton chlorine containers, rear side of container. 

Professor Durbin in front of a Chlorine rotometer. 

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Hard to tell, but these are 1- ton chlorine gas containers. Notice the five gallon bucket of 

motor oil in the bottom photograph. Also notice that this photograph is the only eye wash 

station that we found during our inspection of 10 different facilities. Do you have an eye 

wash and emergency shower? 

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Chlorine Gas 

Background 

Chlorine gas is a pulmonary irritant with intermediate water solubility that causes acute 

damage in the upper and lower respiratory tract. Chlorine gas was first used as a chemical 

weapon at Ypres, France in 1915. Of the 70,552 American soldiers poisoned with various 

gasses in World War I, 1843 were exposed to chlorine gas. Approximately 10.5 million tons 

and over 1 million containers of chlorine are shipped in the U.S. each year. 

Chlorine is a yellowish-green gas at standard temperature and pressure. It is extremely 

reactive with most elements. Because its density is greater than that of air, the gas settles 

low to the ground. It is a respiratory irritant, and it burns the skin. Just a few breaths of it are 

fatal. Cl2 gas does not occur naturally, although Chlorine can be found in a number of 

compounds. 

Atomic Number: 17 

Standard State: Gas at 298K 

Melting Point: 171.6K (-101.5 C) 

Boiling Point: 239.11K (-34.04 C) 

Density: N/A 

Molar Volume: 17.39 cm 3 

Electronegativity: 3.16 Pauling Units 

Crystal Structure: The Diatomic Chlorine molecules arrange themselves in an orthorhombic 

structure. 

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Pathophysiology 

Chlorine is a greenish-yellow, noncombustible gas at room temperature and atmospheric 

pressure. The intermediate water solubility of chlorine accounts for its effect on the upper 

airway and the lower respiratory tract. Exposure to chlorine gas may be prolonged because 

its moderate water solubility may not cause upper airway symptoms for several minutes. In 

addition, the density of the gas is greater than that of air, causing it to remain near ground 

level and increasing exposure time. 

The odor threshold for chlorine is approximately 0.3-0.5 parts per million (ppm); however, 

distinguishing toxic air levels from permissible air levels may be difficult until irritative 

symptoms are present. 

Mechanism of Activity 

The mechanisms of the above biological activity are poorly understood and the predominant 

anatomic site of injury may vary, depending on the chemical species produced. Cellular 

injury is believed to result from the oxidation of functional groups in cell components, from 

reactions with tissue water to form hypochlorous and hydrochloric acid, and from the 

generation of free oxygen radicals. Although the idea that chlorine causes direct tissue 

damage by generating free oxygen radicals was once accepted, this idea is now 

controversial. 

The cylinders on the right contain chlorine gas. The gas comes out of the cylinder through a 

gas regulator. The cylinders are on a scale that operators use to 

measure the amount used each day. The chains are used to 

prevent the tanks from falling over. 

Chlorine gas is stored in vented rooms that have panic bar 

equipped doors. Operators have the equipment necessary to 

reduce the impact of a gas leak, but rely on trained emergency 

response teams to contain leaks. 

Solubility Effects 

Hydrochloric acid is highly soluble in water. The predominant 

targets of the acid are the epithelia of the ocular conjunctivae 

and upper respiratory mucus membranes. 

Hypochlorous acid is also highly water soluble with an injury 

pattern similar to hydrochloric acid. 

Hypochlorous acid may account for the toxicity of elemental 

chlorine and hydrochloric acid to the human body. 

Early Response to Chlorine Gas 

Chlorine gas, when mixed with ammonia, reacts to form chloramine gas. In the presence of 

water, chloramines decompose to ammonia and hypochlorous acid or hydrochloric acid. 

The early response to chlorine exposure depends on the (1) concentration of chlorine gas, (2) 

duration of exposure, (3) water content of the tissues exposed, and (4) individual susceptibility. 

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Immediate Effects 

The immediate effects of chlorine gas toxicity include acute inflammation of the conjunctivae, 

nose, pharynx, larynx, trachea, and bronchi. Irritation of the airway mucosa leads to local 

edema secondary to active arterial and capillary hyperemia. 

Plasma exudation results in filling the alveoli with edema fluid, resulting in pulmonary 

congestion. 

Pathological Findings 

Pathologic findings are nonspecific. They include severe pulmonary edema, pneumonia, 

hyaline membrane formation, multiple pulmonary thromboses, and ulcerative tracheobronchitis. 

The hallmark of pulmonary injury associated with chlorine toxicity is pulmonary edema, 

manifested as hypoxia. Non-cardiogenic pulmonary edema is thought to occur when there is 

a loss of pulmonary capillary integrity. 

1-ton chlorine gas containers. 

Unbelievably, this facility uses between 20 and 30 containers per day. 3 shifts are 

required to handle the chlorine change outs each day. Normally this is a slow boring 

job if everything is working properly. This crew is also responsible for any and all 

chlorine leaks. Even when the fire crews show up for a Cl2 leak, the fire crews are 

too scared to touch a leaking cylinder and will ask the water treatment personnel to 

fix the leak. 

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Chemical Equations, Oxidation States, and Balancing of Equations 

Before we breakdown chlorine and other chemicals, let’s start with this review of basic 

chemical equations. 

Beginning 

The common chemical equation could be A + B --> C + D. This is chemical A + chemical B, 

the two reacting chemicals will go to products C + D, etc. 

Oxidation 

The term “oxidation” originally meant a reaction in which oxygen combines chemically with 

another substance, but its usage has long been broadened to include any reaction in which 

electrons are transferred. 

Oxidation and reduction always occur simultaneously (redox reactions), and the substance 

which gains electrons is termed the oxidizing agent. For example, cupric ion is the oxidizing 

agent in the reaction: Fe (metal) + Cu++ --> Fe++ + Cu (metal); here, two electrons (negative 

charges) are transferred from the iron atom to the copper atom; thus the iron becomes 

positively charged (is oxidized) by loss of two electrons, while the copper receives the two 

electrons and becomes neutral (is reduced). 

Electrons may also be displaced within the molecule without being completely transferred 

away from it. Such partial loss of electrons likewise constitutes oxidation in its broader sense 

and leads to the application of the term to a large number of processes, which at first sight 

might not be considered to be oxidation. Reaction of a hydrocarbon with a halogen, for 

example, CH4 + 2 Cl --> CH3Cl + HCl, involves partial oxidation of the methane; halogen 

addition to a double bond is regarded as an oxidation. 

Dehydrogenation is also a form of oxidation; when two hydrogen atoms, each having one 

electron, are removed from a hydrogen-containing organic compound by a catalytic reaction 

with air or oxygen, as in oxidation of alcohol to aldehyde. 

Oxidation Number 

The number of electrons that must be added to or subtracted from an atom in a combined 

state to convert it to the elemental form; i.e., in barium chloride ( BaCl2) the oxidation number 

of barium is +2 and of chlorine is -1. Many elements can exist in more than one oxidation 

state. 

Now, let us look at some common ions. An ion is the reactive state of the chemical, and is 

dependent on its place within the periodic table. 

Have a look at the “periodic table of the elements”. It is arranged in columns of elements, 

there are 18 columns. You can see column one, H, Li, Na, K, etc. These all become ions as 

H + , Li + , K + , etc. The next column, column 2, Be, Mg, Ca etc. become ions Be 2+ , Mg 2+ , Ca 2+ , 

etc. Column 18, He, Ne, Ar, Kr are inert gases. Column 17, F, Cl, Br, I, ionize to a negative F - 

, Cl - , Br - , I - , etc. 

What you now need to do is memorize the table of common ions, both positive ions and 

negative ions. 

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Table of Common Ions 

Positive Ions 

Valency 1 Valency 2 Valency 3 

lithium Li + magnesium Mg 2+ aluminum Al 3+ 

sodium Na + calcium Ca 2+ iron III Fe 3+ 

potassium K + strontium Sr 2+ chromium Cr 3+ 

silver Ag + barium Ba 2+ 

hydronium H3O + copper II Cu 2+ 

(or hydrogen) H + lead II Pb 2+ 

ammonium NH4 + zinc Zn 2+ 

copper I Cu + manganese II Mn 2+ 

mercury I Hg + iron II Fe 2+ 

tin II Sn 2+ 

Negative Ions 

Valency 1 Valency 2 Valency 3 

fluoride F - oxide O 2- phosphate PO4 3- 

chloride Cl - sulfide S 2- 

bromide Br - carbonate CO3 2- 

iodide I - sulfate SO4 2- 

hydroxide OH - sulfite SO3 2- 

nitrate NO3 - dichromate Cr2O7 - 

bicarbonate HCO3 - chromate CrO4 2- 

bisulphate HSO4 - oxalate C2O4 2- 

nitrite NO2 - thiosulfate S2O3 2- 

chlorate ClO3 - tetrathionate S4O6 2- 

- monohydrogen 

permanganate MnO4 

phosphate 

hypochlorite OCl - 

dihydrogen 

phosphate 

H2PO4 - 

HPO4 2- 

Positive ions will react with negative ions, and vice versa. This is the start of our 

chemical reactions. For example: 

Na + + OH - --> NaOH (sodium hydroxide) 

Na + + Cl - --> NaCl (salt) 

3H + + PO4 3- --> H3PO4 (phosphoric acid) 

2Na + + S2O3 2- --> Na2S2O3 

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You will see from these examples, that if an ion of one (+), reacts with an ion of one (-) 

then the equation is balanced. However, an ion like PO4 3- (phosphate) will require an ion of 

3+ or an ion of one (+) (but needs three of these) to neutralize the 3- charge on the 

phosphate. So, what you are doing is balancing the charges (+) or (-) to make them zero, or 

cancel each other out. 

For example, since aluminum exists in its ionic state as Al 3+ , it will react with many negatively 

charged ions; for example: Cl - , OH - , SO4 2- , PO4 3- . 

Let us do these examples and balance them. 

Al 3+ + Cl - --> AlCl (incorrect) 

Al 3+ + 3Cl - --> AlCl3 (correct) 

How did we work this out? 

Al 3+ has three positives (3+) 

Cl - has one negative (-) 

It will require 3 negative charges to cancel out the 3 positive charges on the aluminum 

( Al 3+ ). 

When the left hand side of the equation is written, to balance the number of chlorine’s (Cl - ) 

required, the number 3 is placed in front of the ion concerned, in this case Cl - , becomes 3Cl - . 

On the right hand side of the equation, where the ions have become a compound 

(a chemical compound), the number is transferred to after the relevant ion, Cl3. 

Another example: 

Al 3+ + SO4 2- --> AlSO4 (incorrect) 

2Al 3+ + 3SO4 2- --> Al2(SO4)3 (correct) 

Let me give you an easy way of balancing: 

Al is 3+ 

SO4 is 2- 

Simply transpose the number of positives (or negatives) for each ion, to the other ion, by 

placing this value of one ion, in front of the other ion. That is, Al 3+ the 3 goes in front of the 

SO4 2- as 3SO4 2- , and SO4 2- , the 2 goes in front of the Al 3+ to become 2Al 3+ . Then on the right 

hand side of the equation, this same number (now in front of each ion on the left side of the 

equation), is placed after each “ion” entity. 

Let us again look at: 

Al 3+ + SO4 2- --> AlSO4 (incorrect) 

Al 3+ + SO4 2- --> Al2(SO4)3 (correct) 

Put the three from the Al in front of the SO4 2- and the 2 from the SO4 2- in front of the Al 3+ . 

Equation becomes: 

2Al 3+ + 3SO4 2- --> Al2(SO4)3. You simply place the valency of one ion, as a whole number, in 

front of the other ion, and vice versa. 

Remember to encase the SO4 in brackets. Why? Because we are dealing with the sulfate 

ion, SO4 2- , and it is this ion that is 2- charged (not just the O4), so we have to ensure that the 

“ion” is bracketed. Now to check, the 2 times 3 + = 6 + , and 3 times 2 - = 6 - . We have equal 

amounts of positive ions, and equal amounts of negative ions. 

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Another example: 

NaOH + HCl --> ? 

Na is Na + , OH is OH - , so this gave us NaOH. Originally, the one positive canceled the one 

negative. 

HCl is H + + Cl - , this gave us HCl. 

Reaction is going to be the Na + reacting with a negatively charged ion. This will have to be 

the chlorine, Cl - , because at the moment the Na + is tied to the OH - . So: Na + + Cl - --> NaCl 

The H+ from the HCl will react with a negative (-) ion this will be the OH - from the NaOH. 

So: H + + OH - --> H2O (water). 

The complete reaction can be written: 

NaOH + HCl --> NaCl + H2O. We have equal amounts of all atoms each side of the 

equation, so the equation is balanced. 

or 

Na + OH - + H + Cl - --> Na + Cl - + H + OH - 

Something More Difficult: 

Mg(OH)2 + H3PO4 --> ? (equation on left not balanced) 

Mg 2+ 2OH - + 3H + PO4 3- --> ? (equation on left not balanced), so let us rewrite the equation in 

ionic form. 

The Mg 2+ needs to react with a negatively charged ion, this will be the PO4 3- , 

so: 3Mg 2+ + 2PO4 3- --> Mg3(PO4)2 

(Remember the swapping of the positive or negative charges on the ions in the left side of 

the equation, and placing it in front of each ion, and then placing this number after each ion 

on the right side of the equation) 

What is left is the H + from the H3PO4 and this will react with a negative ion, we only have the 

OH - from the Mg(OH)2 left for it to react with. 

6H + + 6OH - --> 6H2O 

Where did I get the 6 from? When I balanced the Mg 2+ with the PO4 3- , the equation 

became 3Mg 2+ + 2PO4 3- --> Mg3(PO4)2 

Therefore, I must have required 3Mg(OH)2 to begin with, and 2H3PO4, ( because we 

originally had (OH)2 attached to the Mg, and H3 attached to the PO4. I therefore have 2H3 

reacting with 3(OH)2. We have to write this, on the left side of the equation, as 6H + + 6OH - 

because we need it in ionic form. 

The equation becomes: 

6H + + 6OH - --> 6H2O 

The full equation is now balanced and is: 

3Mg(OH)2 + 2H3PO4 --> Mg3(PO4)2 + 6H2O 

I have purposely split the equation into segments of reactions. This is showing you which 

ions are reacting with each other. Once you get the idea of equations you will not need this 

step. 

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The balancing of equations is simple. You need to learn the valency of the common ions 

(see tables). The rest is pure mathematics; you are balancing valency charges, positives 

versus negatives. You have to have the same number of negatives, or positives, each 

side of the equation, and the same number of ions or atoms each side of the equation. 

If one ion, example Al 3+ , (3 positive charges) reacts with another ion, example OH - (one 

negative ion) then we require 2 more negatively charged ions (in this case OH - ) to counteract 

the 3 positive charges the Al 3+ contains. 

Take my earlier hint, place the 3 from the Al 3+ in front of the OH - , now reads 3OH - , place the 

1 from the hydroxyl OH - in front of the Al 3+ , now stays the same, Al 3+ (the 1 is never written in 

chemistry equations). 

Al 3+ + 3OH - --> Al(OH)3 

The 3 is simply written in front of the OH - , a recognized ion, there are no brackets placed 

around the OH - . On the right hand side of the equation, all numbers in front of each ion on 

the left hand side of the equation are placed after each same ion on the right side of the 

equation. Brackets are used in the right side of the equation because the result is a 

compound. Brackets are also used for compounds (reactants) in the left side of equations, as 

in 3Mg(OH)2 + 2H3PO4 --> ? 

The basic routes for a chemical to enter the body in a laboratory setting are: 

inhalation, skin and eye contact, ingestion, and injection. The prevention of entry by 

one of these routes can be accomplished by control mechanisms such as 

engineering controls, personal protective equipment, and administrative controls. 

Each route can be minimized by a variety of control measures depending on the 

hazard and operation. 

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Top- Baffles for slowing water down prior to settling. 

Bottom- Rectangular sedimentation basins 

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Chemistry of Chlorination 

Chlorine can be added as sodium hypochlorite, calcium hypochlorite or chlorine gas. When 

any of these is added to water, chemical reactions occur as these equations show: 

Cl 2 + H 2 O → HOCI + HCI 

(chlorine gas) (water) (hypochlorous acid) (hydrochloric acid) 

CaOCI + H 2 O → 2HOCI + Ca(OH) 

(calcium hypochlorite) (water) (hypochlorous acid) (calcium hydroxide) 

NaOCI + H 2 O → HOCI + Na(OH) 

(sodium hypochlorite) (water) (hypochlorous acid) (sodium hydroxide) 

All three forms of chlorine produce hypochlorous acid (HOCl) when added to water. 

Hypochlorous acid is a weak acid but a strong disinfecting agent. The amount of 

hypochlorous acid depends on the pH and temperature of the water. Under normal water 

conditions, hypochlorous acid will also chemically react and break down into a hypochlorite 

ion. 

(OCl - ): HOCI H + + OCI – Also expressed HOCI → H + + OCI – 

(hypochlorous acid) (hydrogen) (hypochlorite ion) 

The hypochlorite ion is a much weaker disinfecting agent than hypochlorous acid, about 100 

times less effective. 

Let’s now look at how pH and temperature affect the ratio of hypochlorous acid to 

hypochlorite ions. As the temperature is decreased, the ratio of hypochlorous acid increases. 

Temperature plays a small part in the acid ratio. Although the ratio of hypochlorous acid is 

greater at lower temperatures, pathogenic organisms are actually harder to kill. All other 

things being equal, higher water temperatures and a lower pH are more conducive to 

chlorine disinfection. 

Types of Residual 

If water were pure, the measured amount of chlorine in the water should be the same as the 

amount added. But water is not 100% pure. There are always other substances (interfering 

agents) such as iron, manganese, turbidity, etc., which will combine chemically with the 

chlorine. 

This is called the chlorine demand. Naturally, once chlorine molecules are combined with 

these interfering agents, they are not capable of disinfection. It is free chlorine that is much 

more effective as a disinfecting agent. 

So let’s look now at how free, total, and combined chlorine are related. When a chlorine 

residual test is taken, either a total or a free chlorine residual can be read. 

Total residual is all chlorine that is available for disinfection. 

Total chlorine residual = free + combined chlorine residual. 

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Free chlorine residual is a much stronger disinfecting agent. Therefore, most water regulating 

agencies will require that your daily chlorine residual readings be of free chlorine residual. 

Break-point chlorination is where the chlorine demand has been satisfied; any additional 

chlorine will be considered free chlorine. 

Residual Concentration/Contact Time (CT) Requirements 

Disinfection to eliminate fecal and coliform bacteria may not be sufficient to adequately 

reduce pathogens such as Giardia or viruses to desired levels. Use of the "CT" disinfection 

concept is recommended to demonstrate satisfactory treatment, since monitoring for very low 

levels of pathogens in treated water is analytically very difficult. 

The CT concept, as developed by the United States Environmental Protection Agency 

(Federal Register, 40 CFR, Parts 141 and 142, June 29, 1989), uses the combination of 

disinfectant residual concentration (mg/L) and the effective disinfection contact time (in 

minutes) to measure effective pathogen reduction. The residual is measured at the end of 

the process, and the contact time used is the T10 of the process unit (time for 10% of the 

water to pass). CT= Contact time. 

CT = Concentration (mg/L) x Time (minutes) 

500-pound chlorine gas container and 150-pound Cl2 gas cylinders. The 1/2 ton is 

on a scale. Cylinders stand up-right and containers on their sides. 

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The effective reduction in pathogens can be calculated by reference to standard tables of 

required CTs (see Appendices A and B). 

Required Giardia/Virus Reduction 

All surface water treatment systems shall ensure a minimum reduction in pathogen levels: 

3-log reduction in Giardia and 4-log reduction in viruses. These requirements are based on 

unpolluted raw water sources with Giardia levels of = 1 cyst/100 L, and a finished water goal 

of 1 cyst/100,000 L (equivalent to 1 in 10,000 risk of infection per person per year). Higher 

raw water contamination levels may require greater removals as shown on Table 4.1. 

TABLE 4.1 

LEVEL OF GIARDIA REDUCTION 

Raw Water Giardia Levels* 

Recommended Giardia Log 

Reduction 

< 1 cyst/100 L 3-log 

1 cyst/100 L - 10 cysts/100 L 3-log - 4-log 

10 cysts/100 L - 100 cysts/100 L 4-log - 5-log 

> 100 cysts/100 L > 5-log 

*Use geometric means of data to determine raw water Giardia levels for compliance. 

Required CT Value 

Required CT values are dependent on pH, residual concentration, temperature, and the 

disinfectant used. The tables attached to Appendices A and B shall be used to determine the 

required CT. 

Calculation and Reporting of CT Data 

Disinfection CT values shall be calculated daily, using either the maximum hourly flow and 

the disinfectant residual at the same time, or by using the lowest CT value if it is calculated 

more frequently. Actual CT values are then compared to required CT values. 

Results shall be reported as a reduction Ratio, along with the appropriate pH, temperature, 

and disinfectant residual. The reduction Ratio must be greater than 1.0 to be acceptable. 

Users may also calculate and record actual log reductions. Reduction Ratio = CT actual ÷ 

CT required 

Here is an operator checking for leaks with Ammonia. If there is a Cl2 leak, you will 

be able to see a white smoke. Even if you cannot smell the chlorine, the ammonia 

will find it. 

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Using DPD Method for Chlorine Residuals 

N, N – diethyl-p-phenylenediame 

Small portable chlorine measuring kit. The redder the mixture the “hotter” or stronger 

the chlorine in solution. 

Measuring Chlorine Residual 

Chlorine residual is the amount of chlorine remaining in water that can be used for 

disinfection. A convenient, simple and inexpensive way to measure chlorine residual is to use 

a small portable kit with pre-measured packets of chemicals that are added to water. (Make 

sure you buy a test kit using the DPD method, and not the outdated orthotolodine method.) 

Chlorine test kits are very useful in adjusting the chlorine dose you apply. You can measure 

what chlorine levels are being found in your system (especially at the far ends). 

Free chlorine residuals need to be checked and recorded daily. These results should be kept 

on file for a health or regulatory agency inspection during a regular field visit. 

The most accurate method for determining chlorine residuals is to use the laboratory 

amperometric titration method. 

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Chlorine (DDBP) 

Today, most of our drinking water supplies are free of the micro-organisms — viruses, 

bacteria, and protozoa — that cause serious and life-threatening diseases, such as cholera 

and typhoid fever. This is largely due to the introduction of water treatment, particularly 

chlorination, at the turn of the century. 

Living cells react with chlorine and reduce its concentration while they die. Their organic 

matter and other substances that are present convert to chlorinated derivatives, some of 

which are effective killing agents. Chlorine present as Cl, HOCl, and OCl¯ is called free 

available chlorine and that which is bound but still effective is combined chlorine. A 

particularly important group of compounds with combined chlorine is the chloramines formed 

by reactions with ammonia. 

One especially important feature of disinfection using chlorine is the ease of overdosing to 

create a "residual" concentration. There is a constant danger that safe water leaving the 

treatment plant may become contaminated later. There may be breaks in water mains, loss 

of pressure that permits an inward leak, or plumbing errors. This residual concentration of 

chlorine provides some degree of protection right to the water faucet. With free available 

chlorine, a typical residual is from 0.1 to 0.5 ppm. Because chlorinated organic compounds 

are less effective, a typical residual is 2 ppm for combined chlorine. 

There will be no chlorine residual unless there is an excess over the amount that reacts with 

the organic matter present. However, reaction kinetics complicates interpretation of 

chlorination data. The correct excess is obtained in a method called "Break Point 

Chlorination ". 

Chlorine By-Products 

Chlorination by-products are the chemicals formed when the chlorine used to kill disease- 

causing micro-organisms reacts with naturally occurring organic matter (i.e., decay products 

of vegetation) in the water. The most common chlorination by-products found in U.S. drinking 

water supplies are the trihalomethanes (THMs). 

The Principal Trihalomethanes are: 

Chloroform, bromodichloromethane, chlorodibromomethane, and bromoform. Other less 

common chlorination by-products includes the haloacetic acids and haloacetonitriles. The 

amount of THMs formed in drinking water can be influenced by a number of factors, including 

the season and the source of the water. For example, THM concentrations are generally 

lower in winter than in summer, because concentrations of natural organic matter are lower 

and less chlorine is required to disinfect at colder temperatures. THM levels are also low 

when wells or large lakes are used as the drinking water source, because organic matter 

concentrations are generally low in these sources. The opposite — high organic matter 

concentrations and high THM levels — is true when rivers or other surface waters are used 

as the source of the drinking water. 

Health Effects 

Laboratory animals exposed to very high levels of THMs have shown increased incidences 

of cancer. Also, several studies of cancer incidence in human populations have reported 

associations between long-term exposure to high levels of chlorination by-products and an 

increased risk of certain types of cancer. 

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For instance, a recent study conducted in the Great Lakes basin reported an increased risk 

of bladder and possibly colon cancer in people who drank chlorinated surface water for 35 

years or more. 

Possible relationships between exposure to high levels of THMs and adverse reproductive 

effects in humans have also been examined recently. In a California study, pregnant women 

who consumed large amounts of tap water containing elevated levels of THMs were found to 

have an increased risk of spontaneous abortion. The available studies on health effects do 

not provide conclusive proof of a relationship between exposure to THMs and cancer or 

reproductive effects, but indicate the need for further research to confirm their results and to 

assess the potential health effects of chlorination by-products other than THMs. 

Chlorine storage room, notice the vents at the bottom and top. The bottom vent will 

allow the gas to ventilate because Cl2 gas is heavier than air. 

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Risks and Benefits of Chlorine 

Current evidence indicates that the benefits of chlorinating our drinking water — reduced 

incidence of water-borne diseases — are much greater than the risks of health effects from 

THMs. 

Although other disinfectants are available, chlorine continues to be the choice of water 

treatment experts. When used with modern water filtration practices, chlorine is effective 

against virtually all infective agents — bacteria, viruses, and protozoa. It is easy to apply, and 

most importantly, small amounts of chlorine remain in the water and continue to disinfect 

throughout the distribution system. This ensures that the water remains free of microbial 

contamination on its journey from the treatment plant to the consumer’s tap. 

A number of cities use ozone to disinfect their source water and to reduce THM formation. 

Although ozone is a highly effective disinfectant, it breaks down quickly, so that small 

amounts of chlorine or other disinfectants must be added to the water to ensure continued 

disinfection as the water is piped to the consumer’s tap. Modifying water treatment facilities 

to use ozone can be expensive, and ozone treatment can create other undesirable byproducts 

that may be harmful to health if they are not controlled (i.e., bromate). 

Examples of other disinfectants include chloramines and chlorine dioxide. Chloramines are 

weaker disinfectants than chlorine, especially against viruses and protozoa; however, they 

are very persistent and, as such, can be useful for preventing re-growth of microbial 

pathogens in drinking water distribution systems. 

Chlorine dioxide can be an effective disinfectant, but it forms chlorate and chlorite, 

compounds whose toxicity has not yet been fully determined. Assessments of the health 

risks from these and other chlorine-based disinfectants and chlorination by-products are 

currently under way. In general, the preferred method of controlling chlorination by-products 

is removal of the naturally occurring organic matter from the source water so it cannot react 

with the chlorine to form by-products. THM levels may also be reduced through the 

replacement of chlorine with alternative disinfectants. A third option is removal of the byproducts 

by adsorption on activated carbon beds. It is extremely important that water 

treatment plants ensure the methods used to control chlorination by-products do not 

compromise the effectiveness of water disinfection. 

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Chlorinator Parts 

� Ejector 

� Check Valve Assembly 

� Rate Valve 

� Diaphragm Assembly 

� Interconnection Manifold 

� Rotameter Tube and Float 

� Pressure Gauge 

� Gas Supply 

Chlorine measurement devices or Rotameters. 

Safety Information: There is a fusible plug on every chlorine gas cylinder. This metal 

plug will melt at 158 o to 165 o F. This is to prevent a build-up of excessive pressure 

and the possibility of cylinder rupture due to fire or high temperatures. 

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Chlorination Equipment Requirements 

For all water treatment facilities, chlorine gas under pressure shall not be permitted outside 

the chlorine room. The chlorine room is the room where chlorine gas cylinders and/or ton 

containers are stored. Vacuum regulators shall also be located inside the chlorine room. The 

chlorinator, which is the mechanical gas proportioning equipment, may or may not be located 

inside the chlorine room. 

For new and upgraded facilities, from the chlorine room, chlorine gas vacuum lines should be 

run as close to the point of solution application as possible. Injectors should be located to 

minimize the length of pressurized chlorine solution lines. A gas pressure relief system shall 

be included in the gas vacuum line between the vacuum regulator(s) and the chlorinator(s) to 

ensure that pressurized chlorine gas does not enter the gas vacuum lines leaving the 

chlorine room. 

The gas pressure relief system shall vent pressurized gas to the atmosphere at a location 

that is not hazardous to plant personnel; the vent line should be run in such a manner that 

moisture collecting traps are avoided. The vacuum regulating valve(s) shall have positive 

shutdown in the event of a break in the downstream vacuum lines. As an alternative to 

chlorine gas, it is permissible to use hypochlorite with positive displacement pumping. Antisiphon 

valves shall be incorporated in the pump heads or in the discharge piping. 

Capacity 

The chlorinator shall have the capacity to dose enough chlorine to overcome the demand 

and maintain the required concentration of the "free" or "combined" chlorine. 

Methods of Control 

The chlorine feed system shall be automatic proportional controlled, automatic residual 

controlled, or compound loop controlled. In the automatic proportional controlled system, the 

equipment adjusts the chlorine feed rate automatically in accordance with the flow changes 

to provide a constant pre-established dosage for all rates of flow. In the automatic residual 

controlled system, the chlorine feeder is used in conjunction with a chlorine residual analyzer 

which controls the feed rate of the chlorine feeders to maintain a particular residual in the 

treated water. In the compound loop control system, the feed rate of the chlorinator is 

controlled by a flow proportional signal and a residual analyzer signal to maintain particular 

chlorine residual in the water. Manual chlorine 

feed systems may be installed for groundwater 

systems with constant flow rate. 

Standby Provision 

As a safeguard against malfunction and/or 

shut-down, standby chlorination equipment 

having the capacity to replace the largest unit 

shall be provided. For uninterrupted 

chlorination, gas chlorinators shall be equipped 

with an automatic changeover system. In 

addition, spare parts shall be available for all 

chlorinators. 

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Weigh Scales 

Scales for weighing cylinders shall be provided at all plants using chlorine gas to permit an 

accurate reading of total daily weight of chlorine used. At large plants, scales of the recording 

and indicating type are recommended. At a minimum, a platform scale shall be provided. 

Scales shall be of corrosion-resistant material. Read the scales daily and at the same time. 

Securing Cylinders 

All chlorine cylinders shall be securely positioned to safeguard against movement. Tag the 

cylinder “empty” and store upright and chained. Ton containers may not be stacked. 

Chlorine Leak Detection 

Automatic chlorine leak detection and related alarm equipment shall be installed at all water 

treatment plants using chlorine gas. Leak detection shall be provided for the chlorine rooms. 

Chlorine leak detection equipment should be connected to a remote audible and visual alarm 

system and checked on a regular basis to verify proper operation. 

Leak detection equipment shall not automatically activate the chlorine room ventilation 

system in such a manner as to discharge chlorine gas. During an emergency if the chlorine 

room is unoccupied, the chlorine gas leakage shall be contained within the chlorine room 

itself in order to facilitate a proper method of clean-up. 

Consideration should also be given to the provision of caustic soda solution reaction tanks 

for absorbing the contents of leaking one-ton cylinders where such cylinders are in use. 

Chlorine leak detection equipment may not be required for very small chlorine rooms with an 

exterior door (i.e., floor area less than 3m 2 ).You can use a spray solution of Ammonia or a 

rag soaked with Ammonia to detect a small Cl2 leak. If there is a leak, the ammonia will 

create a white colored smoke, Ammonium Chloride. 

Safety Equipment 

The facility shall be provided with personnel safety equipment to include the following: 

Respiratory equipment, safety shower, eyewash, gloves, eye protection, protective clothing, 

cylinder and/or ton repair kits. 

Respiratory equipment shall be provided which has been approved under the Occupational 

Health and Safety Act, General Safety Regulation - Selection of Respiratory Protective 

Equipment. Equipment shall be in close proximity to the access door(s) of the chlorine room. 

Chlorine Room Design Requirements 

Where gas chlorination is practiced, the gas cylinders and/or the ton containers up to the 

vacuum regulators shall be housed in a gas-tight, well illuminated, corrosion resistant and 

mechanically ventilated enclosure. The chlorinator may or may not be located inside the 

chlorine room. The chlorine room shall be located at the ground floor level. 

Ventilation 

Gas chlorine rooms shall have entirely separate exhaust ventilation systems capable of 

delivering one complete air change per minute during periods of chlorine room occupancy 

only - there shall be no continuous ventilation. The air outlet from the room shall be 150 mm 

above the floor and the point of discharge located to preclude contamination of air inlets to 

buildings or areas used by people. The vents to the outside shall have insect screens. Air 

inlets should be louvered near the ceiling, the air being of such temperature as to not 

adversely affect the chlorination equipment. 

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Separate switches for fans and lights shall be outside the room at all entrance or viewing 

points, and a clear wire-reinforced glass window shall be installed in such a manner as to 

allow the operator to inspect from the outside of the room. 

Heating 

Chlorine rooms shall have separate heating systems, if a forced air system is used to heat 

the building. Hot water heating system for the building will negate the need for a separate 

heating system for the chlorine room. The heat should be controlled at approximately 15 o C. 

Cylinders or containers shall be protected to ensure that the chlorine maintains its gaseous 

state when entering the chlorinator. 

Access 

All access to the chlorine room shall only be from the exterior of the building. Visual 

inspection of the chlorination equipment from inside may be provided by the installation of 

glass window(s) in the walls of the chlorine room. Windows should be at least 0.20 m2 in 

area, and be made of clear wire reinforced glass. There should also be a 'panic bar' on the 

inside of the chlorine room door for emergency exit. 

Storage of Chlorine Cylinders 

If necessary, a separate storage room may be provided to simply store the chlorine gas 

cylinders, with no connection to the line. The chlorine cylinder storage room shall have 

access either to the chlorine room or from the plant exterior, and arranged to prevent the 

uncontrolled release of spilled gas. Chlorine gas storage room shall have provision for 

ventilation at thirty air changes per hour. Viewing glass windows and a panic button on the 

inside of door should also be provided. In very large facilities, entry into the chlorine rooms 

may be through a vestibule from outside. 

Scrubbers 

For facilities located within residential or densely populated areas, consideration shall be 

given to provide scrubbers for the chlorine room. 

Chlorine wrenches and chlorine cylinder fusible plugs. After a couple of months, the 

wrenches will start corroding from the acid created from the moisture and chlorine 

gas. In fact, everything will corrode, including your teeth. 

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Chlorine is a greenish-yellow, noncombustible gas at room temperature and 

atmospheric pressure. The intermediate water solubility of chlorine accounts for its 

effect on the upper airway and the lower respiratory tract. Exposure to chlorine gas 

may be prolonged, because its moderate water solubility may not cause upper airway 

symptoms for several minutes. In addition, the density of the gas is greater than that 

of air, causing it to remain near ground level and increasing exposure time. The odor 

threshold for chlorine is approximately 0.3-0.5 parts per million (ppm); however, 

distinguishing toxic air levels from permissible air levels may be difficult until irritative 

symptoms are present. 

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Troubleshooting Hypochlorination Problems 

Problem 

1. Chemical feed pump won’t run. 

2. Low chlorine residual at POE. (Point of Entry) 

2. Low chlorine residual at POE. 

3. Chemical feed pump won’t prime. 

4. Loss of prime 


1A. No power. 

1B. Electrical problem with signal from well pump or flow sensor. 

1C. Motor failure. 

2A. Improper procedure for running chlorine residual test or expired chemical reagents. 

2B. Pump not feeding an adequate quantity of chlorine. 

2C. Change in raw water quality. 

2D. Pump air bound. 

2E. Chlorine supply tank empty. 

2F. Reduced effectiveness of chlorine solution. 

2G. Damaged suction or discharge lines. (cracks or crimps) 

2H. Connection at point of injection clogged or leaking. 

3A. Speed and stroke setting inadequate. 

3B. Suction lift too high due to feed pump relocation. 

3C. Discharge pressure too high. 

3D. Suction fitting clogged. 

3E. Trapped air in suction line. 

3F. Suction line not submerged in solution. 

4A. Solution tank empty. 

4B. Air leaks in suction fittings. 

4C. Foot valve not in vertical position. 

4D. Air trapped in suction tubing. 


1A. Check to see if plug is securely in place. 

Insure that there is power to the outlet and control systems. 

1B. Check pump motor starter. Bypass flow sensor to determine if pump will operate 

manually. 

1C. Check manufacturer’s information. 

2A Check expiration date on chemical reagents. Check test procedure as described in test 

kit manual. Speed or stroke setting too low. 

2B. Damaged diaphragm or suction leak. 

2C. Test raw water for constituents that may cause increased chlorine demand. (i.e. iron, 

manganese, etc.) 

2D. Check foot valve. 

2E. Fill supply tank. 

2F. Check date that chlorine was received. Sodium hypochlorite solution may lose 

effectiveness after 30 days. If that is the case, the feed rate must be increased to obtain the 

desired residual. 

2G. Clean or repair lines with problems. 

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2H. Flush line and connection with mild acid such as Acetic or Muriatic. Replace any 

damaged parts that may be leaking. 

3A. Check manufacturers’ recommendations for proper settings to prime pump. 

3B. Check maximum suction lift for pump and relocate as necessary. 

3C. Check well pump discharge pressure. 

Check pressure rating on chemical feed pump. 

3D. Clean or replace screen. 

3E. Insure all fittings are tight. 

3F. Add chlorine solution to supply tank. 

4A. Fill tank. 

4B. Check for cracked fittings. 

4C. Adjust foot valve to proper position. 

4D. Check connections and fittings. 

Chlorine Titration 

These chlorine gas containers are unprotected and not fenced in. This is a huge 

security violation and a huge safety risk to the public. You can see a fence in the 

rear, but in reality, there was not complete fencing or any type of security in place. 

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Alternate Disinfectants 

Chloramine 

Chloramine is a very weak disinfectant for Giardia and virus reduction. It is recommended 

that it be used in conjunction with a stronger disinfectant. It is best utilized as a stable 

distribution system disinfectant. 

In the production of chloramines, the ammonia residuals in the finished water, when fed in 

excess of the stoichiometric amount needed, should be limited to inhibit growth of nitrifying 

bacteria. 

Chlorine Dioxide 

Chlorine dioxide may be used for either taste and odor control or as a pre-disinfectant. Total 

residual oxidants (including chlorine dioxide and chlorite, but excluding chlorate) shall not 

exceed 0.30 mg/L during normal operation or 0.50 mg/L (including chlorine dioxide, chlorite 

and chlorate) during periods of extreme variations in the raw water supply. 

Chlorine dioxide provides good Giardia and virus protection, but its use is limited by the 

restriction on the maximum residual of 0.5 mg/L ClO2/chlorite/chlorate allowed in finished 

water. This limits usable residuals of chlorine dioxide at the end of a process unit to less than 

0.5 mg/L. 

Where chlorine dioxide is approved for use as an oxidant, the preferred method of generation 

is to entrain chlorine gas into a packed reaction chamber with a 25% aqueous solution of 

sodium chlorite (NaClO2). 

Warning 

Dry sodium chlorite is explosive and can cause fires in feed equipment if leaking solutions or 

spills are allowed to dry out. 

Ozone 

Ozone is a very effective disinfectant for both Giardia and viruses. Ozone CT values( contact 

time) must be determined for the ozone basin alone; an accurate T10 value must be 

obtained for the contact chamber, residual levels measured through the chamber and an 

average ozone residual calculated. 

Ozone does not provide a system residual and should be used as a primary disinfectant only 

in conjunction with free and/or combined chlorine. 

Ozone does not produce chlorinated byproducts (such as trihalomethanes) but it may cause 

an increase in such byproduct formation if it is fed ahead of free chlorine; ozone may also 

produce its own oxygenated byproducts such as aldehydes, ketones, or carboxylic acids. 

Any installed ozonation system must include adequate ozone leak detection alarm systems, 

and an ozone off-gas destruction system. 

Ozone may also be used as an oxidant for removal of taste and odor, or may be applied as a 

pre-disinfectant. 

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Amperometric Titration 

The chlorination of water supplies and polluted waters serves primarily to destroy or deactivate 

disease-producing microorganisms. A secondary benefit, particularly in treating drinking water, is 

the overall improvement in water quality resulting from the reaction of chlorine with ammonia, 

iron, manganese, sulfide, and some organic substances. 

Chlorination may produce adverse effects. Taste and odor characteristics of phenols and other 

organic compounds present in a water supply may be intensified. Potentially carcinogenic chloroorganic 

compounds such as chloroform may be formed. 

Combined chlorine formed on chlorination of ammonia- or amine-bearing waters adversely affects 

some aquatic life. To fulfill the primary purpose of chlorination and to minimize any adverse 

effects, it is essential that proper testing procedures be used with a foreknowledge of the 

limitations of the analytical determination. 

Chlorine applied to water in its molecular or hypochlorite form initially undergoes hydrolysis to 

form free chlorine consisting of aqueous molecular chlorine, hypochlorous acid, and hypochlorite 

ion. The relative proportion of these free chlorine forms is pH- and temperature-dependent. At the 

pH of most waters, hypochlorous acid and hypochlorite ion will predominate. 

Free chlorine reacts readily with ammonia and certain nitrogenous compounds to form combined 

chlorine. With ammonia, chlorine reacts to form the chloramines: monochloramine, dichloramine, 

and nitrogen trichloride. The presence and concentrations of these combined forms depend 

chiefly on pH, temperature, initial chlorine-to-nitrogen ratio, absolute 

chlorine demand, and reaction time. Both free and combined 

chlorine may be present simultaneously. Combined chlorine in water 

supplies may be formed in the treatment of raw waters containing 

ammonia or by the addition of ammonia or ammonium salts. 

Chlorinated wastewater effluents, as well as certain chlorinated 

industrial effluents, normally contain only combined chlorine. 

Historically the principal analytical problem has been to distinguish 

between free and combined forms of chlorine. 

Hach’s AutoCAT 9000 Automatic Titrator is the newest solution to 

hit the disinfection industry – a comprehensive, bench top chlorine-measurement system that 

does it all: calibration, titration, calculation, real-time graphs, graphic print output, even electrode 

cleaning. More a laboratory assistant than an instrument, the AutoCAT 9000 gives you, high 

throughput, performs the titration and calculates concentration, all automatically: 

� Forward titration: USEPA-accepted methods for free and total chlorine and chlorine 

dioxide with chlorite 

� Back titration: USEPA-accepted method for total chlorine in wastewater 

� Accurate, yet convenient, the easiest way to complete ppb-level amperometric titration 

If you’re dechlorinating, modifying your current disinfectant delivery, changing over to another 

chlorine species, or adjusting disinfection processes to meet new regulations, this is the 

workhorse system that yields the fast, accurate residual readings you need. 

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Additional Drinking Water Methods (Non-EPA) for Chemical 

Parameters 

Method Method Focus Title Location Source 

4500-Cl - 

B 

4500-Cl - 

D 

4500-Cl 

D 

4500-Cl 

E 

4500-Cl 

F 

4500-Cl 

G 

4500-Cl 

H 

Chloride by Silver Nitrate 

Titration 

Chloride by Potentiometric 

Method 

Chlorine Residual by 


(Stage 1 DBP use SM 19th Ed. 

only) 

Chlorine Residual by Low Level 



only) 

Chlorine Residual by DPD 

Ferrous Titration 


only) 

Chlorine Residual by DPD 

Colorimetric Method 


only) 

Chlorine Residual by 

Syringaldazine (FACTS) Method 


only) 

4500-Cl I Chlorine Residual by Iodometric 

Electrode Technique 


only) 

4500- 

ClO2 C 

4500- 

ClO2 D 

4500- 

ClO2 E 

Chlorine Dioxide by the 

Amperometric Method I 

Chlorine Dioxide by the DPD 

Method 


only) 

Chlorine Dioxide by the 

Amperometric Method II 


only) 

Standard Methods for the 

Examination of Water and 

Wastewater, 18th & 19th Ed. 



Wastewater, 18th, 19th & 20th 

Editions 




Editions 




Editions 




Editions 




Editions 




Editions 




Editions 




Editions 




Editions 




Editions 

Included in 

Standard 

Methods 

Included in 


Methods 

Included in 


Methods 

Included in 


Methods 

Included in 


Methods 

Included in 


Methods 

Included in 


Methods 

Included in 


Methods 

Included in 


Methods 

Included in 


Methods 

Included in 


Methods 

American Water 

Works Assn. 

(AWWA) 


Works Assn. 

(AWWA) 


Works Assn. 

(AWWA) 


Works Assn. 

(AWWA) 


Works Assn. 

(AWWA) 


Works Assn. 

(AWWA) 


Works Assn. 

(AWWA) 


Works Assn. 

(AWWA) 


Works Assn. 

(AWWA) 


Works Assn. 

(AWWA) 


Works Assn. 

(AWWA) 

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Chlorine Dioxide Methods 

Most tests for chlorine dioxide rely upon its oxidizing properties. Consequently, numerous test 

kits are readily available that can be adapted to measure chlorine dioxide. In addition, new 

methods that are specific for chlorine dioxide are being developed. The following are the 

common analytical methods for chlorine dioxide: 

DPD 

glycine 

Chloropheno 

l Red 

Direct 

Absorban 

ce 

Method Type: Colorimetric Colorimetric Colorimetri 

c 

How It Works Glycine 

removes Cl2; 

ClO2 forms a 

pink color, 

whose intensity 

is proportional to 

the ClO2 

concentration. 

Range 

ClO2 bleaches 

chlorophenol 

red indicator. 

The degree of 

bleaching is 

proportional to 

the 

concentration 

of ClO2. 

0.5 to 5.0 ppm. 0.1 to 1.0 ppm 

The direct 

measurem 

ent of ClO2 

is 

determine 

d between 

350 and 

450 nM. 

100 to 

1000 ppm 

Interferences Oxidizers None Color, 

turbidity 

Iodometric 

Titration 

Amperometr 

ic Titration 

Titrimetric Titrimetric 

Two aliquots are taken one is 

sparged with N2 to remove 

ClO2. KI is added to the other 

sample at pH7 and titrated to 

a colorless endpoint. The pH 

is lower to 2, the color 

allowed to reform and the 

titration continued. These 

titrations are repeated on the 

sparged sample. 

> 1 ppm < 1ppm 

Oxidizers 

Complexity Simple Moderate Simple Moderate High 

Equipment 

Required 

EPA Status 

Recommendatio 

n 

Approved 

Spectrophotometer 

or Colorimeter 

Not 

approved 

Not 

approved 

Titration 

equipmen 

t 

Not 

approved 

Amperometric 

Titrator 

Approved 

Marginal Yes Marginal Yes Marginal 

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Recommendations for Preparing/Handling/Feeding 

Sodium Hypochlorite Solutions 

As a result of the pressures brought to bear by Health and Safety requirements, some users 

of gas have chosen to seek alternative forms of disinfectants for their water and wastewater 

treatment plants. One of these alternative forms is sodium hypochlorite (NaOCl)). This is 

often purchased commercially at 10 to 15% strength. 

The handling and storage of NaOCl presents the plant with a new and sometimes unfamiliar, 

set of equipment installation configurations and operating conditions. 

Product Stability The oxidizing nature of this substance means that it should be handled 

with extreme care. As NaOCl is relatively unstable, it degrades over time. 

There are three ways in which NaOCl solutions degrade: 

• Chlorate-forming reaction due to age, temperature, light, and minor reduction in pH. 

• Oxygen-producing reaction that occurs when metals, such as iron, copper or nickel, or 

metal oxides are brought into contact with the solution. 

• Chlorine-producing reaction when solution pH falls below 6. 

There are many factors that affect the stability of a NaOCl solution: 

• Initial solution strength. 

• pH solution. 

• Temperature of the solution. 

• Exposure of the solution to sunlight. 

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Shock Chlorination — Well Maintenance 

Shock chlorination is a relatively inexpensive and straightforward procedure used to control 

bacteria in water wells. Many types of bacteria can contaminate wells, but the most common 

are iron and sulfate-reducing bacteria. 

Health Problems 

Although not a cause of health problems in humans, bacteria growth will coat the inside of 

the well casing, water piping, and pumping equipment, creating problems such as: 

� Reduced well yield 

� Restricted water flow in distribution lines 

� Staining of plumbing fixtures and laundry 

� Plugging of water treatment equipment 

� “Rotten egg” odor. 

Bacteria may be introduced during drilling of a well or when pumps are removed for repair 

and laid on the ground. However, iron and sulfate-reducing bacteria (as well as other 

bacteria) can exist naturally in groundwater. A well creates a direct path for oxygen to travel 

into the ground where it would not normally exist. When a well is pumped, the water flowing 

in will also bring in nutrients that enhance bacterial growth. 

Note: All iron staining problems are not necessarily caused by iron bacteria. The iron 

naturally present in the water can be the cause. 

Ideal Conditions for Iron Bacteria 

Water wells provide ideal conditions for iron bacteria. To 

thrive, iron bacteria require 0.5-4 mg/L of dissolved oxygen, as 

little as 0.01 mg/L dissolved iron and a temperature range of 5 

to 15°C. Some iron bacteria use dissolved iron in the water as 

a food source. 

Signs of Iron and Sulfate-Reducing Bacteria 

There are a number of signs that indicate the presence of iron 

and sulfate-reducing bacteria. They include: 

� Slime growth 

� Rotten egg odor 

� Increased staining. 

Slime Growth 

The easiest way to check a well and water system for iron 

bacteria is to examine the inside surface of the toilet flush 

tank. If you see a greasy slime or growth, iron bacteria are probably present. Iron bacteria 

leave this slimy by-product on almost every surface the water is in contact with. 

Rotten Egg Odor 

Sulfate-reducing bacteria can cause a rotten egg odor in water. Iron bacteria aggravate the 

problem by creating an environment that encourages the growth of sulfate-reducing bacteria 

in the well. Sulfate-reducing bacteria prefer to live underneath the slime layer that the iron 

bacteria form. Some of these bacteria produce hydrogen sulfide as a by-product, resulting in 

a “rotten egg” or sulfur odor in the water. Others produce small amounts of sulfuric acid 

which can corrode the well casing and pumping equipment. 

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Increased Staining Problems 

Iron bacteria can concentrate iron in water sources with low iron content. It can create a 

staining problem where one never existed before or make an iron staining problem worse as 

time goes by. Use the following checklist to determine if you have an iron or sulfate-reducing 

bacteria problem. The first three are very specific problems related to these bacteria. The last 

two problems can be signs of other problems as well. 

Checklist to Determine an Iron or Sulfate-Reducing Bacteria Problem 

� Greasy slime on inside surface of toilet flush tank 

� Increased red staining of plumbing fixtures and laundry 

� Sulfur odor 

� Reduced well yield 

� Restricted water flow 

Mixing a Chlorine Solution 

Add a half gallon of bleach to a clean pail with about 3 gallons of water. This is generally 

sufficient to disinfect a 4 inch diameter well 100 feet deep or less. For wells greater than 100 

feet deep or with a larger casing diameter, increase the amount of bleach proportionately. 

If you have a dug well with a diameter greater than 18 inches, use 2 to 4 gallons of bleach 

added directly to the well. Please note that many dug wells are difficult or impossible to 

disinfect due to their unsanitary construction. 

Shock Chlorination — Well Maintenance 

Shock Chlorination Method 

Shock chlorination is used to control iron and sulfate-reducing bacteria, and to eliminate fecal 

coliform bacteria in a water system. To be effective, shock chlorination must disinfect the 

following: 

� The entire well depth 

� The formation around the bottom of the well 

� The pressure system 

� Some water treatment equipment 

� The distribution system. 

To accomplish this, a large volume of super chlorinated water is siphoned down the well to 

displace all the water in the well and some of the water in the formation around the well. 

Effectiveness of Shock Chlorination 

With shock chlorination, the entire system (from the water-bearing formation, through the 

well-bore and the distribution system) is exposed to water which has a concentration of 

chlorine strong enough to kill iron and sulfate reducing bacteria. Bacteria collect in the pore 

spaces of the formation and on the casing or screened surface of the well. To be effective, 

you must use enough chlorine to disinfect the entire cased section of the well and adjacent 

water-bearing formation. The procedure described below does not completely eliminate iron 

bacteria from the water system, but it will hold it in check. 

To control the iron bacteria, you may have to repeat the procedure each spring and fall as a 

regular maintenance procedure. 

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If your well has never been shock chlorinated or has not been done for some time, it may be 

necessary to use a stronger chlorine solution, applied two or three times, before you notice a 

significant improvement in the water. You might also consider hiring a drilling contractor to 

thoroughly clean and flush the well before chlorinating in order to remove any buildup on the 

casing. In more severe cases, the pump may have to be removed and chemical solutions 

added to the well and vigorous agitation carried out using special equipment. This is to 

dislodge and remove the bacterial slime, and should be done by a drilling contractor. 

Shock Chlorination Procedure for Small Drilled Wells 

A modified procedure is also provided for large diameter wells. 

Caution: If your well is low-yielding or tends to pump any silt or sand, you must be very 

careful using the following procedure because over pumping may damage the well. When 

pumping out the chlorinated solution, monitor the water discharge for sediment. 

Don't mix acids with chlorine. This is a dangerous practice. 

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Chlorine Exposure Limits 

This information is often necessary to pass your certification exam. 

* OSHA PEL 1 PPM - IDLH 10 PPM and Fatal Exposure Limit 1,000 PPM 

The current Occupational Safety and Health Administration (OSHA) permissible exposure 

limit (PEL) for chlorine is 1 ppm (3 milligrams per cubic meter (mg/m (3) )) as a ceiling limit. A 

worker's exposure to chlorine shall at no time exceed this ceiling level. * IDLH 10 PPM 

Physical and chemical properties of chlorine: A yellowish green, nonflammable and liquefied 

gas with an unpleasant and irritating smell. Can be readily compressed into a clear, ambercolored 

liquid, a noncombustible gas, and a strong oxidizer. Solid chlorine is about 1.5 times 

heavier than water and gaseous chlorine is about 2.5 times heavier than air. Atomic number 

of chlorine is 17. Cl is the elemental symbol and Cl2 is the chemical formula. 

Monochloramine, dichloramine, and trichloramine are also known as Combined Available 

Chlorine. Cl2 + NH4. 

HOCl and OCl-; the OCL- is the hypochlorite ion and both of these species are known as 

free available chlorine, they are the two main chemical species formed by chlorine in water. 

They are known by collectively as hypochlorous acid and the hypochlorite ion. When chlorine 

gas is added to water, it rapidly hydrolyzes. The chemical equations best describes this 

reaction is Cl2 + H2O --> H+ + Cl- + HOCl. Hypochlorous acid is the most germicidal of the 

chlorine compounds with the possible exception of chlorine dioxide. 

Yoke-type connectors should be used on a chlorine cylinder's valve, 

assuming that the threads on the valve may be worn. 

The connection from a chlorine cylinder to a chlorinator should be 

replaced by using a new, approved gasket on the connector. Always 

follow your manufacturer’s instructions. 

On a 1 ton chlorine gas container, the chlorine pressure reducing valve 

should be located downstream of the evaporator when using an 

evaporator. This is the liquid chlorine supply line and it is going to be 

made into chlorine gas. 

In water treatment, chlorine is added to the effluent before the contact chamber (before the 

clear well) for complete mixing. One reason for not adding it directly to the chamber is that 

the chamber has very little mixing due to low velocities. 

Here are several safety precautions when using chlorine gas: in addition to protective 

clothing and goggles, chlorine gas should be used only in a well-ventilated area so that any 

leaking gas cannot concentrate. Emergency procedures in the case of a large uncontrolled 

chlorine leak are to: notify local emergency response team, warn and evacuate people in 

adjacent areas, and be sure that no one enters the leak area without adequate self-contained 

breathing equipment. 

Here are several symptoms of chlorine exposure: Burning of eyes, nose, and mouth, 

coughing, sneezing, choking, nausea and vomiting, headaches and dizziness, fatal 

pulmonary edema, pneumonia and skin blisters. A little Cl2 will corrode the teeth and then 

progress to throat cancer. 

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Approved method for storing a 150 - 200 pound chlorine cylinder: secure each 

cylinder in an upright position, attach the protective bonnet over the valve, and firmly 

secure each cylinder. Never store near heat. Always store the empty in an upright, 

secure position with proper signage. Bottom photograph Chlorine wrenches that 

have be near Chlorine gas. It takes just a few weeks for a very small undetectable 

chlorine gas leak to oxidize steel or human teeth. 

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Fluoride 

Some water providers will add fluoride to the 

water to help prevent cavities in children. Too 

much fluoride will mottle the teeth. 

Chemical Feed 

The equipment used for feeding the fluoride to 

water shall be accurately calibrated before 

being placed in operation, and at all times shall 

be capable of maintaining a rate of feed within 

5% of the rate at which the machine is set. 

The following chemical feed practices 

apply: 

1. Where a dry feeder of the volumetric or gravimetric type is used, a suitable weighing 

mechanism shall be provided to check the daily amount of chemical feed. 

2. Hoppers should be designed to hold a 24 hour supply of the fluoride compound and designed 

such that the dust hazard to operators is minimized. 

3. Vacuum dust filters shall be installed with the hoppers to prevent dust from rising into the 

room when the hopper is filled. 

4. Dissolving chambers are required for use with dry feeders, and the dissolving chambers shall 

be designed such that at the required rate of feed of the chemical the solution strength will not 

be greater than 1/4 of that of a saturated solution at the temperature of the dissolving water. The 

construction material of the dissolving chamber and associated piping shall be compatible with 

the fluoride solution to be fed. 

5. Solution feeders shall be of the positive displacement type and constructed of material 

compatible with the fluoride solution being fed. 

6. The weight of the daily amount of fluoride fed to water shall be accurately determined. 

7. Feeders shall be provided with anti-siphon valves on the discharge side. Wherever possible, 

positive anti-siphon breakers other than valves shall be provided. 

8. A "day tank" capable of holding a 24 hour supply of solution should be provided. 

9. All equipment shall be sized such that it will be operated in the 20 to 80 percent range of the 

scale, and be capable of feeding over the entire pumpage range of the plant. 

10. Alarm signals are recommended to detect faulty operation of equipment; and, 

11. The fluoride solution should be added to the water supply at a point where the fluoride will 

not be removed by any following treatment processes and where it will be mixed with the water. 

It is undesirable to inject the fluoride compound or solution directly on-line unless there are 

provisions for adequate mixing. 

Metering 

Metering of the total water to be fluoridated shall be provided, and the operation of the feeding 

equipment is to be controlled. Control of the feed rate shall be automatic/ proportional 

controlled, whereby the fluoride feed rate is automatically adjusted in accordance with the flow 

changes to provide a constant pre-established dosage for all rates of flow, or (2) automatic/ 

residual controlled, whereby a continuous automatic fluoride analyzer determines the residual 

fluoride level and adjusts the rate of feed accordingly, or compound loop controlled, whereby the 

feed rate is controlled by a flow proportional signal and residual analyzer signal to maintain a 

constant residual. 

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Alternate Compounds 

Any one of the following fluoride compounds may be used: 

1. Hydrofluosilicic acid, 

2. Sodium fluoride or, 

3. Sodium silicofluoride. 

Other fluoride compounds may be used, if approved by the EPA. 

Chemical Storage and Ventilation 

The fluoride chemicals shall be stored separately from other chemicals, and the storage area 

shall be marked "FLUORIDE CHEMICALS ONLY". The storage area should be in close 

proximity to the feeder, kept relatively dry, and provided with pallets (if using bagged chemical) 

to allow circulation of air and to keep the containers off the floor. 

Record of Performance 

Accurate daily records shall be kept. These records shall include: 

1. The daily reading of the water meter which controls the fluoridation equipment or that which 

determines the amount of water to which the fluoride is added. 

2. The daily volume of water fluoridated. 

3. The daily weight of fluoride compound in the feeder. 

4. The daily weight of fluoride compound in stock. 

5. The daily weight of the fluoride compound fed to the water; and, 

6. The fluoride content of the raw and fluoridated water determined by laboratory analysis, with 

the frequency of measurement as follows: 

(i) treated water being analyzed continuously or once daily, and 

(ii) raw water being analyzed at least once a week. 

Sampling 

In keeping the fluoride records, the following sampling procedures are required: 

1. A sample of raw water and a sample of treated water shall be forwarded to an approved 

independent laboratory for fluoride analysis once a month. 

2. On new installations or during start-ups of existing installations, weekly samples of raw and 

treated water for a period of not less than four consecutive weeks. 

3. In addition to the reports required, the EPA may require other information that is deemed 

necessary. 

Fluoride Safety 

The following safety procedures shall be maintained: 

1. All equipment shall be maintained at a high standard of efficiency, and all areas and 

appliances shall be kept clean and free of dust. Wet or damp cleaning methods shall be 

employed wherever practicable. 

2. Personal protective equipment shall be used during the clean-up, and appropriate covers 

shall be maintained over all fluoride solutions. 

3. At all installations, safety features are to be considered and the necessary controls built into 

the installation to prevent an overdose of fluoride in the water. This shall be done either by use 

of day tanks or containers, anti-siphon devices, over-riding flow switches, sizing of pump and 

feeders, determining the length and duration of impulses, or other similar safety devices. 

4. Safety features shall also be provided to prevent spills and overflows. 

5. Individual dust respirators, chemical safety face shields, rubber gloves, and protective 

clothing shall be worn by all personnel when handling or being exposed to the fluoride dust. 

6. Chemical respirators, rubber gloves, boots, chemical safety goggles and acid proof aprons 

shall be worn where acids are handled. 

7. After use, all equipment shall be thoroughly cleaned and stored in an area free of fluoride 

dusts. Rubber articles shall be washed in water, and hands shall be washed after the equipment 

is stored; and, 

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8. All protective devices, whether for routine or emergency use, shall be inspected periodically 

and maintained in good operating condition. 

Repair and Maintenance 

Upon notifying the appropriate local board of health, a fluoridation program may be discontinued 

when necessary to repair or replace equipment, but shall be placed in operation immediately 

after the repair replacement is complete. Records shall be maintained and submitted during the 

period that the equipment is not in operation. 

Sample sink 

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Here is a small groundwater production well that utilizes a submersible pump instead of 

a vertical turbine pump. Bottom, a soft-start electrical panel. 

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Pump, Motor and Hydraulic Section 

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A centrifugal pump has two main components: 

I. A rotating component comprised of an impeller and a shaft 

II. A stationary component comprised of a casing, casing cover, and bearings. 

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Common Hydraulic Terms 

Head 

The height of a column or body of fluid above a given point expressed in linear units. Head is 

often used to indicate gauge pressure. Pressure is equal to the height times the density of the 

liquid. 

Head, Friction 

The head required to overcome the friction at the interior surface of a conductor and between 

fluid particles in motion. It varies with flow, size, type, and conditions of conductors and fittings, 

and the fluid characteristics. 

Head, static 

The height of a column or body of fluid above a given point. 

Hydraulics 

Engineering science pertaining to liquid pressure and flow. 

Hydrokinetics 

Engineering science pertaining to the energy of liquid flow and pressure. 

Pascal's Law 

A pressure applied to a confined fluid at rest is transmitted with equal intensity throughout the 

fluid. 

Pressure 

The application of continuous force by one body upon another that it is touching; compression. 

Force per unit area, usually expressed in pounds per square inch (Pascal or bar). 

Pressure, Absolute 

The pressure above zone absolute, i.e. the sum of atmospheric and gauge pressure. In vacuum 

related work it is usually expressed in millimeters of mercury. (mmHg). 

Pressure, Atmospheric 

Pressure exported by the atmosphere at any specific location. (Sea level pressure is 

approximately 14.7 pounds per 

square inch absolute, 1 bar = 

14.5psi.) 

Pressure, Gauge 

Pressure differential above or 

below ambient atmospheric 

pressure. 

Pressure, Static 

The pressure in a fluid at rest. 

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Top- Compartment style Flocculation Basins 

Bottom – Filter backwash draining filter 

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Hydraulic Principles Section 

Definition Hydraulics is a branch of engineering concerned mainly with moving liquids. The 

term is applied commonly to the study of the mechanical properties of water, other liquids, and 

even gases when the effects of compressibility are small. Hydraulics can be divided into two 

areas, hydrostatics and hydrokinetics. 

Hydraulics The Engineering science pertaining to liquid pressure and flow. 

The word hydraulics is based on the Greek word for water, and originally covered the study of 

the physical behavior of water at rest and in motion. Use has broadened its meaning to include 

the behavior of all liquids, although it is primarily concerned with the motion of liquids. 

Hydraulics includes the manner in which liquids act 

in tanks and pipes, deals with their properties, and 

explores ways to take advantage of these properties. 

Hydrostatics, the consideration of liquids at rest, 

involves problems of buoyancy and flotation, 

pressure on dams and submerged devices, and 

hydraulic presses. The relative incompressibility of 

liquids is one of its basic principles. Hydrodynamics, 

the study of liquids in motion, is concerned with such 

matters as friction and turbulence generated in pipes 

by flowing liquids, the flow of water over weirs and 

through nozzles, and the use of hydraulic pressure in 

machinery. 

Hydrostatics 

Hydrostatics is about the pressures exerted by a fluid 

at rest. Any fluid is meant, not just water. Research 

and careful study on water yields many useful results 

of its own, however, such as forces on dams, 

buoyancy and hydraulic actuation, and is well worth 

studying for such practical reasons. Hydrostatics is 

an excellent example of deductive mathematical 

physics, one that can be understood easily and completely from a very few fundamentals, and 

in which the predictions agree closely with experiment. 

There are few better illustrations of the use of the integral calculus, as well as the principles of 

ordinary statics, available to the student. A great deal can be done with only elementary 

mathematics. Properly adapted, the material can be used from the earliest introduction of school 

science, giving an excellent example of a quantitative science with many possibilities for handson 

experiences. 

The definition of a fluid deserves careful consideration. Although time is not a factor in 

hydrostatics, it enters in the approach to hydrostatic equilibrium. It is usually stated that a fluid is 

a substance that cannot resist a shearing stress, so that pressures are normal to confining 

surfaces. Geology has now shown us clearly that there are substances which can resist 

shearing forces over short time intervals, and appear to be typical solids, but which flow like 

liquids over long time intervals. Such materials include wax and pitch, ice, and even rock. 

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A ball of pitch, which can be shattered by a hammer, will spread out and flow in months. Ice, a 

typical solid, will flow in a period of years, as shown in glaciers, and rock will flow over hundreds 

of years, as in convection in the mantle of the earth. 

Shear earthquake waves, with periods of seconds, propagate deep in the earth, though the rock 

there can flow like a liquid when considered over centuries. The rate of shearing may not be 

strictly proportional to the stress, but exists even with low stress. 

Viscosity may be the physical property that varies over the largest numerical range, competing 

with electrical resistivity. There are several familiar topics in hydrostatics which often appears in 

expositions of introductory science, and which are also of historical interest and can enliven 

their presentation. Let’s start our study with the principles of our atmosphere. 

Atmospheric Pressure 

The atmosphere is the entire mass of air that surrounds the earth. While it extends upward for 

about 500 miles, the section of primary interest is the portion that rests on the earth’s surface 

and extends upward for about 7 1/2 miles. This layer is called the troposphere. 

If a column of air 1-inch square extending all the way to the "top" of the atmosphere could be 

weighed, this column of air would weigh approximately 14.7 pounds at sea level. Thus, 

atmospheric pressure at sea level is approximately 14.7 psi. 

As one ascends, the atmospheric pressure decreases by approximately 1.0 psi for every 2,343 

feet. However, below sea level, in excavations and depressions, atmospheric pressure 

increases. Pressures under water differ from those under air only because the weight of the 

water must be added to the pressure of the air. 

Atmospheric pressure can be measured by any of several methods. The common laboratory 

method uses the mercury column barometer. The height of the mercury column serves as an 

indicator of atmospheric pressure. At sea level and at a temperature of 0° Celsius (C), the 

height of the mercury column is approximately 30 inches, or 76 centimeters. This represents a 

pressure of approximately 14.7 psi. The 30-inch column is used as a reference standard. 

Another device used to measure atmospheric pressure is the aneroid barometer. The aneroid 

barometer uses the change in shape of an evacuated metal cell to measure variations in 

atmospheric pressure. The thin metal of the aneroid cell moves in or out with the variation of 

pressure on its external surface. This movement is transmitted through a system of levers to a 

pointer, which indicates the pressure. 

The atmospheric pressure does not vary uniformly with altitude. It changes very rapidly. 

Atmospheric pressure is defined as the force per unit area exerted against a surface by the 

weight of the air above that surface. In the diagram on the following page, the pressure at point 

"X" increases as the weight of the air above it increases. The same can be said about 

decreasing pressure, where the pressure at point "X" decreases if the weight of the air above it 

also decreases. 

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Barometric Loop 

The barometric loop consists of a continuous section of 

supply piping that abruptly rises to a height of approximately 

35 feet and then returns back down to the originating level. It 

is a loop in the piping system that effectively protects against 

backsiphonage. It may not be used to protect against backpressure. 

Its operation, in the protection against backsiphonage, is 

based upon the principle that a water column, at sea level 

pressure, will not rise above 33.9 feet. In general, barometric 

loops are locally fabricated, and are 35 feet high. 

Pressure may be referred to using an absolute scale, pounds 

per square inch absolute (psia), or gauge scale, (psiag). 

Absolute pressure and gauge pressure are related. Absolute 

pressure is equal to gauge pressure plus the atmospheric 

pressure. At sea level, the atmospheric pressure is 14.7 

psai. 

Absolute pressure is the total pressure. Gauge pressure is 

simply the pressure read on the gauge. If there is no 

pressure on the gauge other than atmospheric, the gauge will 

read zero. Then the absolute pressure would be equal to 

14.7 psi, which is the atmospheric pressure. 

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Pressure 

By a fluid, we have a material in mind like water or air, two very common and important fluids. 

Water is incompressible, while air is very compressible, but both are fluids. Water has a definite 

volume; air does not. Water and air have low viscosity; that is, layers of them slide very easily 

on one another, and they quickly assume their permanent shapes when disturbed by rapid 

flows. Other fluids, such as molasses, may have high viscosity and take a long time to come to 

equilibrium, but they are no less fluids. The coefficient of viscosity is the ratio of the shearing 

force to the velocity gradient. Hydrostatics deals with permanent, time-independent states of 

fluids, so viscosity does not appear, except as discussed in the Introduction. 

A fluid, therefore, is a substance that cannot exert any permanent forces tangential to a 

boundary. Any force that it exerts on a boundary must be normal to the boundary. Such a force 

is proportional to the area on which it is exerted, and is called a pressure. We can imagine any 

surface in a fluid as dividing the fluid into parts pressing on each other, as if it were a thin 

material membrane, and so think of the pressure at any point in the fluid, not just at the 

boundaries. In order for any small element of the fluid to be in equilibrium, the pressure must be 

the same in all directions (or the element would move in the direction of least pressure), and if 

no other forces are acting on the body of the fluid, the pressure must be the same at all 

neighboring points. 

Therefore, in this case the pressure will be the same throughout the fluid, and the same in any 

direction at a point (Pascal's Principle). Pressure is expressed in units of force per unit area 

such as dyne/cm 2 , N/cm 2 (pascal), pounds/in 2 (psi) or pounds/ft 2 (psf). The axiom that if a 

certain volume of fluid were somehow made solid, the equilibrium of forces would not be 

disturbed, is useful in reasoning about forces in fluids. 

On earth, fluids are also subject to the force of gravity, which acts vertically downward, and has 

a magnitude γ = ρg per unit volume, where g is the acceleration of gravity, approximately 981 

cm/s 2 or 32.15 ft/s 2 , ρ is the density, the mass per unit volume, expressed in g/cm 3 , kg/m 3 , or 

slug/ft 3 , and γ is the specific weight, measured in lb/in 3 , or lb/ft 3 (pcf). 

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Gravitation is an example of a body force that disturbs the equality of pressure in a fluid. The 

presence of the gravitational body force causes the pressure to increase with depth, according 

to the equation dp = ρg dh, in order to support the water above. We call this relation the 

barometric equation, for when this equation is integrated, we find the variation of pressure with 

height or depth. If the fluid is incompressible, the equation can be integrated at once, and the 

pressure as a function of depth h is p = ρgh + p0. 

The density of water is about 1 g/cm 3 , or its specific weight 

is 62.4 pcf. We may ask what depth of water gives the 

normal sea-level atmospheric pressure of 14.7 psi, or 2117 

psf. 

This is simply 2117 / 62.4 = 33.9 ft of water. This is the 

maximum height to which water can be raised by a suction 

pump, or, more correctly, can be supported by atmospheric 

pressure. Professor James Thomson (brother of William 

Thomson, Lord Kelvin) illustrated the equality of pressure 

by a "curtain-ring" analogy shown in the diagram. A section 

of the toroid was identified, imagined to be solidified, and 

its equilibrium was analyzed. 

The forces exerted on the curved surfaces have no 

component along the normal to a plane section, so the 

pressures at any two points of a plane must be equal, since 

the fluid represented by the curtain ring was in equilibrium. 

The right-hand part of the diagram illustrates the equality of 

pressures in orthogonal directions. This can be extended to 

any direction whatever, so Pascal's Principle is established. This demonstration is similar to the 

usual one using a triangular prism and considering the forces on the end and lateral faces 

separately. 

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Free Surface Perpendicular to Gravity 

When gravity acts, the liquid assumes a free surface perpendicular to gravity, which can be 

proved by Thomson's method. A straight cylinder of unit cross-sectional area (assumed only for 

ease in the arithmetic) can be used to find the increase of pressure with depth. Indeed, we see 

that p2 = p1 + ρgh. The upper surface of the cylinder can be placed at the free surface if 

desired. The pressure is now the same in any direction at a point, but is greater at points that lie 

deeper. From this same figure, it is easy to prove Archimedes’ Principle that the buoyant force is 

equal to the weight of the displaced fluid, and passes through the center of mass of this 

displaced fluid. 

Geometric Arguments 

Ingenious geometric arguments can be used to 

substitute for easier, but less transparent arguments 

using calculus. For example, the force acting on one 

side of an inclined plane surface whose projection is 

AB can be found as in the diagram on the previous 

page. O is the point at which the prolonged projection 

intersects the free surface. The line AC' perpendicular 

to the plane is made equal to the depth AC of point A, 

and line BD' is similarly drawn equal to BD. The line 

OD' also passes through C', by proportionality of 

triangles OAC' and OAD'. Therefore, the thrust F on 

the plane is the weight of a prism of fluid of crosssection 

AC'D'B, passing through its centroid normal to 

plane AB. Note that the thrust is equal to the density 

times the area times the depth of the center of the 

area; its line of action does not pass through the 

center, but below it, at the center of thrust. The same 

result can be obtained with calculus by summing the 

pressures and the moments. 

Atmospheric Pressure and its Effects 

Suppose a vertical pipe is stood in a pool of water, 

and a vacuum pump applied to the upper end. Before 

we start the pump, the water levels outside and inside the pipe are equal, and the pressures on 

the surfaces are also equal and are equal to the atmospheric pressure. 

Now start the pump. When it has sucked all the air out above the water, the pressure on the 

surface of the water inside the pipe is zero, and the pressure at the level of the water on the 

outside of the pipe is still the atmospheric pressure. Of course, there is the vapor pressure of 

the water to worry about if you want to be precise, but we neglect this complication in making 

our point. We require a column of water 33.9 ft high inside the pipe, with a vacuum above it, to 

balance the atmospheric pressure. Now do the same thing with liquid mercury, whose density at 

0 °C is 13.5951 times that of water. The height of the column is 2.494 ft, 29.92 in, or 760.0 mm. 

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Standard Atmospheric Pressure 

This definition of the standard atmospheric pressure was established by Regnault in the mid- 

19th century. In Britain, 30 in. Hg (inches of mercury) had been used previously. As a practical 

matter, it is convenient to measure pressure differences by measuring the height of liquid 

columns, a practice known as manometry. The barometer is a familiar example of this, and 

atmospheric pressures are traditionally given in terms of the length of a mercury column. To 

make a barometer, the barometric tube, closed at one end, is filled with mercury and then 

inverted and placed in a mercury reservoir. Corrections must be made for temperature, because 

the density of mercury depends on the temperature, and the brass scale expands for capillarity 

if the tube is less than about 1 cm in diameter, 

and even slightly for altitude, since the value 

of g changes with altitude. 

The vapor pressure of mercury is only 

0.001201 mmHg at 20°C, so a correction from 

this source is negligible. For the usual case of 

a mercury column (α = 0.000181792 per °C) 

and a brass scale (&alpha = 0.0000184 per 

°C) the temperature correction is -2.74 mm at 

760 mm and 20°C. Before reading the 

barometer scale, the mercury reservoir is 

raised or lowered until the surface of the 

mercury just touches a reference point, which 

is mirrored in the surface so it is easy to 

determine the proper position. An aneroid 

barometer uses a partially evacuated chamber of thin metal that expands and contracts 

according to the external pressure. This movement is communicated to a needle that revolves in 

a dial. The materials and construction are arranged to give a low temperature coefficient. The 

instrument must be calibrated before use, and is usually arranged to read directly in elevations. 

An aneroid barometer is much easier to use in field observations, such as in reconnaissance 

surveys. In a particular case, it would be read at the start of the day at the base camp, at 

various points in the vicinity, and then finally at the starting point, to determine the change in 

pressure with time. The height differences can be calculated from h = 60,360 log (P/p) [1 + (T + 

t - 64)/986) feet, where P and p are in the same units, and T, t are in °F. 

An absolute pressure is referring to a vacuum, while a gauge pressure is referring to the 

atmospheric pressure at the moment. A negative gauge pressure is a (partial) vacuum. When a 

vacuum is stated to be so many inches, this means the pressure below the atmospheric 

pressure of about 30 in. A vacuum of 25 inches is the same thing as an absolute pressure of 5 

inches (of mercury). 

Vacuum 

The term vacuum indicates that the absolute pressure is less than the atmospheric pressure 

and that the gauge pressure is negative. A complete or total vacuum would mean a pressure of 

0 psia or –14.7 psig. Since it is impossible to produce a total vacuum, the term vacuum, as 

used in this document, will mean all degrees of partial vacuum. In a partial vacuum, the 

pressure would range from slightly less than 14.7 psia (0 psig) to slightly greater than 0 psia (- 

14.7 psig). Backsiphonage results from atmospheric pressure exerted on a liquid, forcing it 

toward a supply system that is under a vacuum. 

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Water Pressure 

The weight of a cubic foot of water is 62.4 pounds per square foot. The base can be subdivided 

into 144-square inches with each subdivision being subjected to a pressure of 0.433 psig. 

Suppose you placed another cubic foot of water on top of the first cubic foot. The pressure on 

the top surface of the first cube which was originally atmospheric, or 0 psig, would now be 

0.4333 psig as a result of the additional cubic foot of water. The pressure of the base of the first 

cubic foot would be increased by the same amount of 0.866 psig or two times the original 

pressure. 

Pressures are very frequently stated in terms of the height of a fluid. If it is the same fluid whose 

pressure is being given, it is usually called "head," and the factor connecting the head and the 

pressure is the weight density ρg. In the English engineer's system, weight density is in pounds 

per cubic inch or cubic foot. A head of 10 ft is equivalent to a pressure of 624 psf, or 4.33 psi. It 

can also be considered an energy availability of ft-lb per lb. Water with a pressure head of 10 ft 

can furnish the same energy as an equal amount of water raised by 10 ft. Water flowing in a 

pipe is subject to head loss because of friction. 

Take a jar and a basin of water. Fill the jar with water and invert it under the water in the basin. 

Now raise the jar as far as you can without allowing its mouth to come above the water surface. 

It is always a little surprising to see that the jar does not empty itself, but the water remains with 

no visible means of support. By blowing through a straw, one can put air into the jar, and as 

much water leaves as air enters. In fact, this is a famous method of collecting insoluble gases in 

the chemical laboratory, or for supplying hummingbird 

feeders. It is good to remind oneself of exactly the 

balance of forces involved. 

Another application of pressure is the siphon. The 

name is Greek for the tube that was used for drawing 

wine from a cask. This is a tube filled with fluid 

connecting two containers of fluid, normally rising 

higher than the water levels in the two containers, at 

least to pass over their rims. In the diagram, the two 

water levels are the same, so there will be no flow. 

When a siphon goes below the free water levels, it is 

called an inverted siphon. If the levels in the two 

basins are not equal, fluid flows from the basin with 

the higher level into the one with the lower level, until 

the levels are equal. 

A siphon can be made by filling the tube, closing the 

ends, and then putting the ends under the surface on both sides. Alternatively, the tube can be 

placed in one fluid and filled by sucking on it. When it is full, the other end is put in place. The 

analysis of the siphon is easy, and should be obvious. The pressure rises or falls as described 

by the barometric equation through the siphon tube. There is obviously a maximum height for 

the siphon which is the same as the limit of the suction pump, about 34 feet. Inverted siphons 

are sometimes used in pipelines to cross valleys. Differences in elevation are usually too great 

to use regular siphons to cross hills, so the fluids must be pressurized by pumps so the 

pressure does not fall to zero at the crests. 

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Liquids at Rest 

In studying fluids at rest, we are concerned with the transmission of force and the factors which 

affect the forces in liquids. Additionally, pressure in and on liquids and factors affecting pressure 

are of great importance. 

Pressure and Force 

Pressure is the force that pushes water through pipes. Water pressure determines the flow of 

water from the tap. If pressure is not sufficient then the flow can reduce to a trickle and it will 

take a long time to fill a kettle or a cistern. 

The terms force and pressure are used extensively in the study of fluid power. It is essential 

that we distinguish between the terms. 

Force means a total push or pull. It is the push or pull exerted against the total area of a 

particular surface and is expressed in pounds or grams. Pressure means the amount of push or 

pull (force) applied to each unit area of the surface and is expressed in pounds per square inch 

(lb/in 2 ) or grams per square centimeter (gm/cm 2 ). Pressure maybe exerted in one direction, in 

several directions, or in all directions. 

Computing Force, Pressure, and Area 

A formula is used in computing force, pressure, and area in fluid power systems. In this formula, 

P refers to pressure, F indicates force, and A represents area. Force equals pressure times 

area. Thus, the formula is written: 

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General Pumping Fundamentals 

Here are the important points to consider about suction piping when the liquid being pumped is 

below the level of the pump: 

� First, suction lift is when the level of water to be pumped is below the centerline of the 

pump. Sometimes suction lift is also referred to as ‘negative suction head’. 

� The ability of the pump to lift water is the result of a partial vacuum created at the center 

of the pump. 

� This works similar to sucking soda from a straw. As you gently suck on a straw, you are 

creating a vacuum or a pressure differential. Less pressure is exerted on the liquid inside 

the straw, so that the greater pressure is exerted on the liquid around the outside of the 

straw, causing the liquid in the straw to move up. By sucking on the straw, this allows 

atmospheric pressure to move the liquid. 

� Look at the diagram illustrated as “1”. The foot valve is located at the end of the suction 

pipe of a pump. It opens to allow water to enter the suction side, but closes to prevent 

water from passing back out of the bottom end. 

� The suction side of pipe should be one diameter larger than the pump inlet. The required 

eccentric reducer should be turned so that the top is flat and the bottom tapered. 

Notice in illustration “2” that the liquid is above the level of the pump. Sometimes this is referred 

to as ‘flooded suction’ or ‘suction head’ situations. 

Points to Note are: 

If an elbow and bell are used, they should be at least one pipe diameter from the tank bottom 

and side. This type of suction piping must have a gate valve which can be used to prevent the 

reverse flow when the pump has to be removed. In the illustrations you can see in both cases 

the discharge head is from the centerline of the pump to the level of the discharge water. The 

total head is the difference between the two liquid levels. 

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Pump Definitions (Larger Glossary in the rear of this manual) 

Fluid: Any substance that can be pumped such as oil, water, refrigerant, or even air. 

Gasket: Flat material that is compressed between two flanges to form a seal. 

Gland follower: A bushing used to compress the packing in the stuffing box and to control 

leakoff. 

Gland sealing line: A line that directs sealing fluid to the stuffing box. 

Horizontal pumps: Pumps in which the center line of the shaft is horizontal. 

Impeller: The part of the pump that increases the speed of the fluid being handled. 

Inboard: The end of the pump closest to the motor. 

Inter-stage diaphragm: A barrier that separates stages of a multi-stage pump. 

Key: A rectangular piece of metal that prevents the impeller from rotating on the shaft. 

Keyway: The area on the shaft that accepts the key. 

Kinetic energy: Energy associated with motion. 

Lantern ring: A metal ring located between rings of packing that distributes gland sealing fluid. 

Leak-off: Fluid that leaks from the stuffing box. 

Mechanical seal: A mechanical device that seals the pump stuffing box. 

Mixed flow pump: A pump that uses both axial-flow and radial-flow components in one 

impeller. 

Multi-stage pumps: Pumps with more than one impeller. 

Outboard: The end of the pump farthest from the motor. 

Packing: Soft, pliable material that seals the stuffing box. 

Positive displacement pumps: Pumps that move fluids by physically displacing the fluid inside 

the pump. 

Radial bearings: Bearings that prevent shaft movement in any direction outward from the center 

line of the pump. 

Radial flow: Flow at 90° to the center line of the shaft. 

Retaining nut: A nut that keeps the parts in place. 

Rotor: The rotating parts, usually including the impeller, shaft, bearing housings, and all other 

parts included between the bearing housing and the impeller. 

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Score: To cause lines, grooves or scratches. 

Shaft: A cylindrical bar that transmits power from the driver to the pump impeller. 

Shaft sleeve: A replaceable tubular covering on the shaft. 

Shroud: The metal covering over the vanes of an impeller. 

Slop drain: The drain from the area that collects leak-off from the stuffing box. 

Slurry: A thick, viscous fluid, usually containing small particles. 

Stages: Impellers in a multi-stage pump. 

Stethoscope: A metal device that can amplify and pinpoint pump sounds. 

Strainer: A device that retains solid pieces while letting liquids through. 

Stuffing box: The area of the pump where the shaft penetrates the casing. 

Suction: The place where fluid enters the pump. 

Suction eye: The place where fluid enters the pump impeller. 

Throat bushing: A bushing at the bottom of the stuffing box that prevents packing from being 

pushed out of the stuffing box into the suction eye of the impeller. 

Thrust: Force, usually along the center line of the pump. 

Thrust bearings: Bearings that prevent shaft movement back and forth in the same direction as 

the center line of the shaft. 

Troubleshooting: Locating a problem. 

Vanes: The parts of the impeller that push and increase the speed of the fluid in the pump. 

Vertical pumps: Pumps in which the center line of the shaft runs vertically. 

Volute: The part of the pump that changes the speed of the fluid into pressure. 

Wearing rings: Replaceable rings on the impeller or the casing that wear as the pump operates. 

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Basic Pump 

Pumps are used to move or raise fluids. They are not only very useful, but are excellent 

examples of hydrostatics. Pumps are of two general types, hydrostatic or positive displacement 

pumps, and pumps depending on dynamic forces, such as centrifugal pumps. Here we will only 

consider positive displacement pumps, which can be understood purely by hydrostatic 

considerations. They have a piston (or equivalent) moving in a closely-fitting cylinder and forces 

are exerted on the fluid by motion of the piston. 

We have already seen an important example of this in the hydraulic lever or hydraulic press, 

which we have called quasi-static. The simplest pump is the syringe, filled by withdrawing the 

piston and emptied by pressing it back in, as its port is immersed in the fluid or removed from it. 

More complicated pumps have valves allowing them to work repetitively. These are usually 

check valves that open to allow passage in one direction, and close automatically to prevent 

reverse flow. There are many kinds of valves, and they are usually the most trouble-prone and 

complicated part of a pump. The force pump has two check valves in the cylinder, one for 

supply and the other for delivery. The supply valve opens when the cylinder volume increases, 

the delivery valve when the cylinder volume decreases. 

The lift pump has a supply valve and a valve in the piston that allows the liquid to pass around it 

when the volume of the cylinder is reduced. The delivery in this case is from the upper part of 

the cylinder, which the piston does not enter. 

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Diaphragm pumps are force pumps in which the oscillating diaphragm takes the place of the 

piston. The diaphragm may be moved mechanically, or by the pressure of the fluid on one side 

of the diaphragm. 

Some positive displacement pumps are shown below. The force and lift pumps are typically 

used for water. The force pump has two valves in the cylinder, while the lift pump has one valve 

in the cylinder and one in the piston. The maximum lift, or "suction," is determined by the 

atmospheric pressure, and either cylinder must be within this height of the free surface. The 

force pump, however, can give an arbitrarily large pressure to the discharged fluid, as in the 

case of a diesel engine injector. A nozzle can be used to convert the pressure to velocity, to 

produce a jet, as for firefighting. Fire fighting force pumps usually have two cylinders feeding 

one receiver alternately. The air space in the receiver helps to make the water pressure uniform. 

The three pumps below are typically used for air, but would be equally applicable to liquids. The 

Roots blower has no valves, their place taken by the sliding contact between the rotors and the 

housing. The Roots blower can either exhaust a receiver or provide air under moderate 

pressure, in large volumes. The Bellows is a very old device, requiring no accurate machining. 

The single valve is in one or both sides of the expandable chamber. Another valve can be 

placed at the nozzle if required. The valve can be a piece of soft leather held close to holes in 

the chamber. The Bicycle pump uses the valve on the valve stem of the tire or inner tube to hold 

pressure in the tire. The piston, which is attached to the discharge tube, has a flexible seal that 

seals when the cylinder is moved to compress the air, but allows air to pass when the 

movement is reversed. 

Diaphragm and vane pumps are not shown, but they act the same way by varying the volume of 

a chamber, and directing the flow with check valves. 

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Types of Pumps 

The family of pumps comprises a large number of types based on application and capabilities. 

The two major groups of pumps are dynamic and positive displacement. 

Dynamic Pumps (Centrifugal Pump) 

Centrifugal pumps are classified into three general categories: 

Radial flow—a centrifugal pump in which the pressure is developed wholly by centrifugal force. 

Mixed flow—a centrifugal pump in which the pressure is developed partly by centrifugal force 

and partly by the lift of the vanes of the impeller on the liquid. 

Axial flow—a centrifugal pump in which the pressure is developed by the propelling or lifting 

action of the vanes of the impeller on the liquid. 

Positive Displacement Pumps 

A Positive Displacement Pump has an expanding cavity on the suction side of the pump and a 

decreasing cavity on the discharge side. Liquid is allowed to flow into the pump as the cavity on 

the suction side expands and the liquid is forced out of the discharge as the cavity collapses. 

This principle applies to all types of Positive Displacement Pumps whether the pump is a rotary 

lobe, gear within a gear, piston, diaphragm, screw, progressing cavity, etc. 

A Positive Displacement Pump, unlike a Centrifugal Pump, will produce the same flow at a 

given RPM no matter what the discharge pressure is. A Positive Displacement Pump cannot be 

operated against a closed valve on the discharge side of the pump, i.e. it does not have a shutoff 

head like a Centrifugal Pump does. If a Positive Displacement Pump is allowed to operate 

against a closed discharge valve it will continue to produce flow which will increase the pressure 

in the discharge line until either the line bursts or the pump is severely damaged or both. 

Types of Positive Displacement Pumps 

Single Rotor Multiple Rotor 

Vane Gear 

Piston Lobe 

Flexible Member Circumferential Piston 

Single Screw Multiple Screw 

There are many types of positive displacement 

pumps. We will look at: 

� Plunger pumps 

� Diaphragm pumps 

� Progressing cavity pumps, and 

� Screw pumps 

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Single Rotator 

Component Description 

Vane The vane(s) may be blades, buckets, rollers, or slippers that cooperate with 

a dam to draw fluid into and out of the pump chamber. 

Piston Fluid is drawn in and out of the pump chamber by a piston(s) reciprocating 

within a cylinder(s) and operating port valves. 

Flexible Member Pumping and sealing depends on the elasticity of a flexible member(s) that 

may be a tube, vane, or a liner. 

Single Screw Fluid is carried between rotor screw threads as they mesh with internal 

threads on the stator. 

Multiple Rotator 

Component Description 

Gear Fluid is carried between gear teeth and is expelled by the meshing of the 

gears that cooperate to provide continuous sealing between the pump inlet 

and outlet. 

Lobe Fluid is carried between rotor lobes that cooperate to provide continuous 

sealing between the pump inlet and outlet. 

Circumferential piston Fluid is carried in spaces between piston surfaces not requiring contacts 

between rotor surfaces. 

Multiple Screw Fluid is carried between rotor screw threads as they mesh. 

What kind of mechanical device do you think is used to provide this positive displacement 

in the: 

Plunger pump? 

Diaphragm pump? 

In the same way, the progressing cavity and the screw are two other types of mechanical action 

that can be used to provide movement of the liquid through the pump. 

Plunger Pump 

The plunger pump is a positive displacement pump that uses a plunger or piston to force liquid 

from the suction side to the discharge side of the pump. It is used for heavy sludge. The 

movement of the plunger or piston inside the pump creates pressure inside the pump, so you 

have to be careful that this kind of pump is never operated against any closed discharge valve. 

All discharge valves must be open before the pump is started, to prevent any fast build-up of 

pressure that could damage the pump. 

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Diaphragm Pumps 

In this type of pump, a diaphragm provides the mechanical action used to force liquid from the 

suction to the discharge side of the pump. The advantage the diaphragm has over the plunger is 

that the diaphragm pump does not come in contact with moving metal. This can be important 

when pumping abrasive or corrosive materials. 

There are three main types of diaphragm pumps available: 

1. Diaphragm sludge pump 

2. Chemical metering or proportional pump 

3. Air-powered double-diaphragm pump 

Pump Categories 

Let's cover the essentials first. The key to the whole operation is, of course, the pump. And 

regardless of what type it is (reciprocating piston, centrifugal, turbine or jet-ejector, for either 

shallow or deep well applications), its purpose is to move water and generate the delivery force 

we call pressure. Sometimes — with centrifugal pumps in particular — pressure is not referred 

to in pounds per square inch but rather as the equivalent in elevation, called head. No matter; 

head in feet divided by 2.31 equals pressure, so it's simple enough to establish a common 

figure. 

Pumps may be classified on the basis of the application they serve. All pumps may be divided 

into two major categories: (1) dynamic, in which energy is continuously added to increase the 

fluid velocities within the machine, and (2) displacement, in which the energy is periodically 

added by application of force. 

Dynamic 

Centrifugal 

Pumps 

Axial flow Mixed Flow Peripheral 

Displacement 

Reciprocating Rotary 

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Split-case centrifugal pump. 

BFP – 12 inch diameter multi-bowl vertical turbine well pump. 

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Understanding the Water Pump 

The water pump commonly found in our systems is centrifugal pumps. These pumps work by 

spinning water around in a circle inside a cylindrical pump housing. The pump makes the water 

spin by pushing it with an impeller. The blades of this impeller project outward from an axle like 

the arms of a turnstile and, as the impeller spins, the water spins with it. As the water spins, the 

pressure near the outer edge of the pump housing becomes much higher than near the center 

of the impeller. 

There are many ways to understand this rise in pressure, and here are two: 

First, you can view the water between the impeller blades as an object traveling in a circle. 

Objects do not naturally travel in a circle--they need an inward force to cause them to accelerate 

inward as they spin. Without such an inward force, an object will travel in a straight line and will 

not complete the circle. In a centrifugal pump, that inward force is provided by high-pressure 

water near the outer edge of the pump housing. The water at the edge of the pump pushes 

inward on the water between the impeller blades and makes it possible for that water to travel in 

a circle. The water pressure at the edge of the turning impeller rises until it is able to keep water 

circling with the impeller blades. 

You can also view the water as an incompressible fluid, one that obeys Bernoulli's equation in 

the appropriate contexts. As water drifts outward between the impeller blades of the pump, it 

must move faster and faster because its circular path is getting larger and larger. The impeller 

blades cause the water to move faster and faster. By the time the water has reached the outer 

edge of the impeller, it is moving quite fast. However, when the water leaves the impeller and 

arrives at the outer edge of the cylindrical pump housing, it slows down. 

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Here is where Bernoulli's equation figures in. As the water slows down and its kinetic energy 

decreases, that water's pressure potential energy increases (to conserve energy). Thus, the 

slowing is accompanied by a pressure rise. That is why the water pressure at the outer edge of 

the pump housing is higher than the water pressure near the center of the impeller. When water 

is actively flowing through the pump, arriving 

through a hole near the center of the impeller and 

leaving through a hole near the outer edge of the 

pump housing, the pressure rise between center 

and edge of the pump is not as large. 

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Types of Water Pumps 

The most common type of water pumps used for municipal and domestic water supplies are 

variable displacement pumps. A variable displacement pump will produce at different rates 

relative to the amount of pressure or lift the pump is working against. Centrifugal pumps are 

variable displacement pumps that are by far used the most. The water production well industry 

almost exclusively uses Turbine pumps, which are a type of centrifugal pump. 

The turbine pump utilizes impellers enclosed in single or multiple bowls or stages to lift water by 

centrifugal force. The impellers may be of either a semi-open or closed type. Impellers are 

rotated by the pump motor, which provides the horsepower needed to overcome the pumping 

head. A more thorough discussion of how these and other pumps work is presented later in 

this section. The size and number of stages, horsepower of the motor and pumping head are 

the key components relating to the pump’s lifting capacity. 

Vertical turbine pumps are commonly used in groundwater wells. These pumps are driven by a 

shaft rotated by a motor on the surface. The shaft turns the impellers within the pump housing 

while the water moves up the column. 

This type of pumping system is also called a line-shaft turbine. The rotating shaft in a line shaft 

turbine is actually housed within the column pipe that delivers the water to the surface. The 

size of the column, impeller, and bowls are selected based on the desired pumping rate and lift 

requirements. 

Column pipe sections can be threaded or coupled together while the drive shaft is coupled and 

suspended within the column by spider bearings. The spider bearings provide both a seal at the 

column pipe joints and keep the shaft aligned within the column. The water passing through the 

column pipe serves as the lubricant for the bearings. Some vertical turbines are lubricated by 

oil rather than water. These pumps are essentially the same as water lubricated units; only the 

drive shaft is enclosed within an oil tube. 

Food grade oil is supplied to the tube through a gravity feed system during operation. The oil 

tube is suspended within the column by spider flanges, while the line shaft is supported within 

the oil tube by brass or redwood bearings. A continuous supply of oil lubricates the drive shaft 

as it proceeds downward through the oil tube. 

A small hole located at the top of the pump bow unit allows excess oil to enter the well. This 

results in the formation of an oil film on the water surface within oil-lubricated wells. Careful 

operation of oil lubricated turbines is needed to ensure that the pumping levels do not drop 

enough to allow oil to enter the pump. Both water and oil lubricated turbine pump units can be 

driven by electric or fuel powered motors. Most installations use an electric motor that is 

connected to the drive shaft by a keyway and nut. However, where electricity is not readily 

available, fuel powered engines may be connected to the drive shaft by a right angle drive gear. 

Also, both oil and water lubricated systems will have a strainer attached to the intake to prevent 

sediment from entering the pump. 

When the line shaft turbine is turned off, water will flow back down the column, turning the 

impellers in a reverse direction. A pump and shaft can easily be broken if the motor were to 

turn on during this process. This is why a time delay or ratchet assembly is often installed on 

these motors to either prevent the motor from turning on before reverse rotation stops or simply 

not allow it to reverse at all. 

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There are three main types of diaphragm pumps: 

In the first type, the diaphragm is sealed with one side in the fluid to be pumped, and the other 

in air or hydraulic fluid. The diaphragm is flexed, causing the volume of the pump chamber to 

increase and decrease. A pair of non-return check valves prevents reverse flow of the fluid. 

As described above, the second type of diaphragm pump works with volumetric positive 

displacement, but differs in that the prime mover of the diaphragm is neither oil nor air; but is 

electro-mechanical, working through a crank or geared motor drive. This method flexes the 

diaphragm through simple mechanical action, and one side of the diaphragm is open to air. The 

third type of diaphragm pump has one or more unsealed diaphragms with the fluid to be 

pumped on both sides. The diaphragm(s) again are flexed, causing the volume to change. 

When the volume of a chamber of either type of pump is increased (the diaphragm moving up), 

the pressure decreases, and fluid is drawn into the chamber. When the chamber pressure later 

increases from decreased volume (the diaphragm moving down), the fluid previously drawn in is 

forced out. Finally, the diaphragm moving up once again draws fluid into the chamber, 

completing the cycle. This action is similar to that of the cylinder in an internal combustion 

engine. 

Cavitation 

Cavitation is defined as the phenomenon of formation of vapor bubbles of a flowing liquid in a 

region where the pressure of the liquid falls below its vapor pressure. Cavitation is usually 

divided into two classes of behavior: inertial (or transient) cavitation and non-inertial cavitation. 

Inertial cavitation is the process where a void or bubble in a liquid rapidly collapses, producing a 

shock wave. Such cavitation often occurs in pumps, propellers, impellers, and in the vascular 

tissues of plants. Non-inertial cavitation is the process in which a bubble in a fluid is forced to 

oscillate in size or shape due to some form of energy input, such as an acoustic field. Such 

cavitation is often employed in ultrasonic cleaning baths and can also be observed in pumps, 

propellers etc. 

Cavitation is, in many cases, an undesirable occurrence. In devices such as propellers and 

pumps, cavitation causes a great deal of noise, damage to components, vibrations, and a loss 

of efficiency. When the cavitation bubbles collapse, they force liquid energy into very small 

volumes, thereby creating spots of high temperature and emitting shock waves, the latter of 

which are a source of noise. The noise created by cavitation is a particular problem for military 

submarines, as it increases the chances of being detected by passive sonar. Although the 

collapse of a cavity is a relatively low-energy event, highly localized collapses can erode metals, 

such as steel, over time. The pitting caused by the collapse of cavities produces great wear on 

components and can dramatically shorten a propeller's or pump's lifetime. After a surface is 

initially affected by cavitation, it tends to erode at an accelerating pace. The cavitation pits 

increase the turbulence of the fluid flow and create crevasses that act as nucleation sites for 

additional cavitation bubbles. The pits also increase the component's surface area and leave 

behind residual stresses. This makes the surface more prone to stress corrosion. 

Impeller 

An impeller is a rotating component of a centrifugal pump, usually made of iron, steel, aluminum 

or plastic, which transfers energy from the motor that drives the pump to the fluid being pumped 

by accelerating the fluid outwards from the center of rotation. The velocity achieved by the 

impeller transfers into pressure when the outward movement of the fluid is confined by the 

pump casing. Impellers are usually short cylinders with an open inlet (called an eye) to accept 

incoming fluid, vanes to push the fluid radically, and a splined center to accept a driveshaft. 

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Submersible Pumps 

Submersible pumps are in essence very similar to turbine pumps. They both use impellers 

rotated by a shaft within the bowls to pump water. However, the pump portion is directly 

connected to the motor. 

The pump shaft has a keyway in which the splined motor end shaft inserts. The motor is bolted 

to the pump housing. The pump’s intake is located between the motor and the pump and is 

normally screened to prevent sediment from entering the pump and damaging the impellers. 

The efficient cooling of submersible motors is very important, so these types of pumps are often 

installed such that flow through the well screen can occur upwards past the motor and into the 

intake. If the motor end is inserted below the screened interval or below all productive portions 

of the aquifer, it will not be cooled, resulting in premature motor failure. 

Some pumps may have pump shrouds installed on them to force all the water to move past the 

motor to prevent overheating. 

The shroud is a piece of pipe that attaches to the pump housing with an open end below the 

motor. As with turbine pumps, the size of the bowls and impellers, number of stages, and 

horsepower of the motor are adjusted to achieve the desired production rate within the 

limitations of the pumping head. 

Insertion of motor spline into the pump keyway. 

Cut away of a small submersible pump. 

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Key Pump Words 

NPSH: Net positive suction head - related to how much suction lift a pump can achieve by 

creating a partial vacuum. Atmospheric pressure then pushes liquid into the pump. A method of 

calculating if the pump will work or not. 

S.G.: Specific gravity. The weight of liquid in comparison to water at approx. 20 degrees C (SG 

= 1). 

Specific Speed: A number which is the function of pump flow, head, efficiency etc. Not used in 

day to day pump selection, but very useful, as pumps with similar specific speed will have 

similar shaped curves, similar efficiency / NPSH / solids handling characteristics. 

Vapor Pressure: If the vapor pressure of a liquid is greater than the surrounding air pressure, 

the liquid will boil. 

Viscosity: A measure of a liquid's resistance to flow. i.e.: how thick it is. The viscosity 

determines the type of pump used, the speed it can run at, and with gear pumps, the internal 

clearances required. 

Friction Loss: The amount of pressure / head required to 'force' liquid through pipe and 

fittings. 

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Understanding the Operation of a Vertical Turbine Pump 

Vertical turbine pumps are available in deep well, shallow well, or canned 

configurations. VHS or VSS motors will be provided to fulfill environmental 

requirements. Submersible motors are also available. These pumps are also 

suitable industrial, municipal, commercial and agricultural applications. 

Deep well turbine pumps are adapted for use in cased wells or where the water 

surface is below the practical limits of a centrifugal pump. Turbine pumps are 

also used with surface water systems. Since the intake for the turbine pump is 

continuously under water, priming is not a concern. Turbine pump efficiencies 

are comparable to, or greater than most centrifugal pumps. They are usually 

more expensive than centrifugal pumps and more difficult to inspect and repair. 

The turbine pump has three main parts: (1) the head assembly, (2) the shaft 

and column assembly and (3) the pump bowl assembly. The head is normally cast iron and 

designed to be installed on a foundation. It supports the column, shaft, and bowl assemblies, 

and provides a discharge for the water. It also will support either an electric motor, a right angle 

gear drive or a belt drive. 

Bowl Assembly 

The bowl assembly is the heart of the vertical turbine pump. The impeller and diffuser type 

casing is designed to deliver the head and capacity that the system requires in the most efficient 

way. Vertical turbine pumps can be multi-staged, allowing maximum flexibility both in the initial 

pump selection and in the event that future system modifications require a change in the pump 

rating. The submerged impellers allow the pump to be started without priming. The discharge 

head changes the direction of flow from vertical to horizontal, and couples the pump to the 

system piping, in addition to supporting and aligning the driver. 

Drivers 

A variety of drivers may be used; however, electric motors are most common. For the purposes 

of this manual, all types of drivers can be grouped into two categories: 

1. Hollow shaft drivers where the pump shaft extends through a tube in the center of the rotor 

and is connected to the driver by a clutch assembly at the top of the driver. 

2. Solid shaft drivers where the rotor shaft is solid and projects below the driver mounting base. 

This type of driver requires an adjustable flanged coupling for connecting to the pump. 

Discharge Head Assembly 

The discharge head supports the driver and bowl assembly as well as supplying a discharge 

connection (the “NUF” type discharge connection which will be located on one of the column 

pipe sections below the discharge head). A shaft sealing arrangement is located in the 

discharge head to seal the shaft where it leaves the liquid chamber. The shaft seal will usually 

be either a mechanical seal assembly or stuffing box. 

Column Assembly 

The shaft and column assembly provides a connection between the head and pump bowls. The 

line shaft transfers the power from the motor to the impellers and the column carries the water 

to the surface. The line shaft on a turbine pump may be either water lubricated or oil lubricated. 

The oil-lubricated pump has an enclosed shaft into which oil drips, lubricating the bearings. The 

water-lubricated pump has an open shaft. The bearings are lubricated by the pumped water. If 

there is a possibility of fine sand being pumped, select the oil lubricated pump because it will 

keep the sand out of the bearings. If the water is for domestic or livestock use, it must be free of 

oil and a water-lubricated pump must be used. 

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Line shaft bearings are commonly placed on 10-foot centers for water-lubricated pumps 

operating at speeds under 2,200 RPM and at 5-foot centers for pumps operating at higher 

speeds. Oil-lubricated bearings are commonly placed on 5-foot centers. 

A pump bowl encloses the impeller. Due to its limited diameter, each impeller develops a 

relatively low head. In most deep well turbine installations, several bowls are stacked in series 

one above the other. This is called staging. A four-stage bowl assembly contains four impellers, 

all attached to a common shaft and will operate at four times the discharge head of a singlestage 

pump. 

Impellers used in turbine pumps may be either semi-open or enclosed. The vanes on semi-open 

impellers are open on the bottom and they rotate with a close tolerance to the bottom of the 

pump bowl. The tolerance is critical and must be adjusted when the pump is new. During the 

initial break-in period the line shaft couplings will tighten, therefore, after about 100 hours of 

operation, the impeller adjustments should be checked. After break-in, the tolerance must be 

checked and adjusted every three to five years or more often if pumping sand. 

Column assembly is of two basic types, either of which may be used: 

1. Open lineshaft construction utilizes the fluid being pumped to lubricate the lineshaft bearings. 

2. Enclosed lineshaft construction has an enclosing tube around the lineshaft and utilizes oil, 

grease or injected liquid (usually clean water) to lubricate the lineshaft bearings. 

Column assembly will consist of: 

1) column pipe, which connects the bowl assembly to the discharge head, 

2) shaft, connecting the bowl shaft to the driver and, 

3) may contain bearings, if required, for the particular unit. Column pipe may be either threaded 

or flanged. 

Note: Some units will not require column assembly, having the bowl assembly connected 

directly to the discharge head instead. 

Bowl Assemblies 

The bowl consists of: 

1) impellers rigidly mounted on the bowl shaft, which rotate and impart energy to the fluid, 

2) bowls to contain the increased pressure and direct the fluid, 

3) suction bell or case which directs the fluid into the first impeller, and 

4) bearings located in the suction bell (or case) and in each bowl. 

Both types of impellers may cause inefficient pump operation if they are not properly adjusted. 

Mechanical damage will result if the semi-open impellers are set too low and the vanes rub 

against the bottom of the bowls. The adjustment of enclosed impellers is not as critical; 

however, they must still be checked and adjusted. 

Impeller adjustments are made by tightening or loosening a nut on the top of the head 

assembly. Impeller adjustments are normally made by lowering the impellers to the bottom of 

the bowls and adjusting them upward. The amount of upward adjustment is determined by how 

much the line shaft will stretch during pumping. The adjustment must be made based on the 

lowest possible pumping level in the well. The proper adjustment procedure if often provided by 

the pump manufacturer. 

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Basic Operation of a Vertical Turbine 

Pre-start 

Before starting the pump, the following checks should be made: 

1. Rotate the pump shaft by hand to make sure the pump is free and the impellers are correctly 

positioned. 

2. Is the head shaft adjusting nut properly locked into position? 

3. Has the driver been properly lubricated in accordance with the instructions furnished with the 

driver? 

4. Has the driver been checked for proper rotation? If not, the pump must be disconnected from 

the driver before checking. The driver must rotate COUNTER CLOCKWISE when looking down 

at the top of the driver. 

5. Check all connections to the driver and control equipment. 

6. Check that all piping connections are tight. 

7. Check all anchor bolts for tightness. 

8. Check all bolting and tubing connections for tightness (driver mounting bolts, flanged coupling 

bolts, glad plate bolts, seal piping, etc.). 

9. On pumps equipped with stuffing box, make sure the gland nuts are only finger tight — DO 

NOT TIGHTEN packing gland before starting. 

10. On pumps equipped with mechanical seals, clean fluid should be put into the seal chamber. 

With pumps under suction pressure this can be accomplished by bleeding all air and vapor out 

of the seal chamber and allowing the fluid to enter. With pumps not under suction pressure, the 

seal chamber should be flushed liberally with clean fluid to provide initial lubrication. Make sure 

the mechanical seal is properly adjusted and locked 

into place. 

NOTE: After initial start-up, pre-lubrication of the mechanical seal will usually not be 

required, as enough liquid will remain in the seal chamber for subsequent start-up 

lubrication. 

11. On pumps equipped with enclosed lineshaft, lubricating liquid must be available and should 

be allowed to run into the enclosing tube in sufficient quantity to thoroughly lubricate all lineshaft 

bearings. 

Initial Start-Up 

1. If the discharge line has a valve in it, it should be partially open for initial starting — Min. 10%. 

2. Start lubrication liquid flow on enclosed lineshaft units. 

3. Start the pump and observe the operation. If there is any difficulty, excess noise or vibration, 

stop the pump immediately. 

4. Open the discharge valve as desired. 

5. Check complete pump and driver for leaks, loose connections or improper operation. 

6. If possible, the pump should be left running for approximately ½ hour on the initial start-up. 

This will allow the bearings, packing or seals, and other parts to “run-in” and reduce the 

possibility of trouble on future starts. 

NOTE: If abrasives or debris are present upon startup, the pump should be allowed to run until 

the pumpage is clean. Stopping the pump when handling large amounts of abrasives (as 

sometimes present on initial starting) may lock the pump and cause more damage than if the 

pump is allowed to continue operation. 

CAUTION: Every effort should be made to keep abrasives out of lines, sumps, etc. so that 

abrasives will not enter the pump. 

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Stuffing Box Adjustment 

On the initial starting it is very important that the packing gland not be tightened too much. New 

packing must be “run in” properly to prevent damage to the shaft and shortening of the packing 

life. The stuffing box must be allowed to leak for proper operation. The proper amount of 

leakage can be determined by checking the temperature of the leakage; this should be cool or 

just lukewarm — NOT HOT. When adjusting the packing gland, bring both nuts down evenly 

and in small steps until the leakage is reduced as required. The nuts should only be tightened 

about ½ turn at a time at 20 to 30 minute intervals to allow the packing to “run in”. Under proper 

operation, a set of packing will last a long time. Occasionally a new ring of packing will need to 

be added to keep the box full. After adding two or three rings of packing, or when proper 

adjustment cannot be achieved, the stuffing box should be cleaned completely of all old packing 

and re-packed. 

Lineshaft Lubrication 

Open lineshaft bearings are lubricated by the pumped fluid and on close coupled units (less 

than 30’ long), will usually not require pre or post lubrication. Enclosed lineshaft bearings are 

lubricated by extraneous liquid (usually oil or clean water), which is fed to the tension nut by 

either a gravity flow system or pressure injection system. The gravity flow system utilizing oil is 

the most common arrangement. The oil reservoir must be kept filled with a good quality light 

turbine oil (about 150 SSU at operating temperature) and adjusted to feed 10 to 12 drops per 

minute plus one (1) drop per 100’ of setting. Injection systems are designed for each installation 

— injection pressure and quantity of lubricating liquid will vary. Refer to packing slip or separate 

instruction sheet for requirements when unit is designed for injection lubrication. 

General Maintenance Section 

A periodic inspection is recommended as the best means of preventing breakdown and keeping 

maintenance costs to a minimum. Maintenance personnel should look over the whole 

installation with a critical eye each time the pump is inspected — a change in noise level, 

amplitude or vibration, or performance can be an indication of impending trouble. Any deviation 

in performance or operation from what is expected can be traced to some specific cause. 

Determination of the cause of any misperformance or improper operation is essential to the 

correction of the trouble — whether the correction is done by the user, the dealer or reported 

back to the factory. Variances from initial performance will indicate changing system conditions 

or wear or impending breakdown of unit. 

Deep well turbine pumps must have correct alignment between the pump and the power unit. 

Correct alignment is made easy by using a head assembly that matches the motor and 

column/pump assembly. It is very important that the well is straight and plumb. The pump 

column assembly must be vertically aligned so that no part touches the well casing. Spacers are 

usually attached to the pump column to prevent the pump assembly from touching the well 

casing. If the pump column does touch the well casing, vibration will wear holes in the casing. A 

pump column out of vertical alignment may also cause excessive bearing wear. 

The head assembly must be mounted on a good foundation at least 12 inches above the ground 

surface. A foundation of concrete provides a permanent and trouble-free installation. The 

foundation must be large enough to allow the head assembly to be securely fastened. The 

foundation should have at least 12 inches of bearing surface on all sides of the well. In the case 

of a gravel-packed well, the 12-inch clearance is measured from the outside edge of the gravel 

packing. 

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Vertical Turbine Pump 

Large Diameter Submersible 

Pump, Motor, and Column Pipe 

Larger check valve installed on 

submersible pump to prevent water 

hammer (notice motor shaft splines.) 

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Common Elements of Vertical Turbines 

Above, Vertical Turbine 

Pump Being Removed 

(Notice line shaft) 

Below 

Closed Pump Impeller 

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Centrifugal Pump 

By definition, a centrifugal pump is a machine. More specifically, it is a machine that imparts 

energy to a fluid. This energy infusion can cause a liquid to flow, rise to a higher level, or both. 

The centrifugal pump is an extremely simple machine. It is a member of a family known as 

rotary machines and consists of two basic parts: 1) the rotary element or impeller and 2) the 

stationary element or casing (volute). The figure at the bottom of the page is a cross section of a 

centrifugal pump and shows the two basic parts. 

In operation, a centrifugal pump “slings” liquid out of the impeller via centrifugal force. One fact 

that must always be remembered: A pump does not create pressure, it only provides flow. 

Pressure is just an indication of the amount of resistance to flow. 

Centrifugal pumps may be classified in several ways. For example, they may be either SINGLE 

STAGE or MULTI-STAGE. A single-stage pump has only one impeller. A multi-stage pump has 

two or more impellers housed together in one casing. 

As a rule, each impeller acts separately, discharging to the suction of the next stage impeller. 

This arrangement is called series staging. Centrifugal pumps are also classified as 

HORIZONTAL or VERTICAL, depending upon the position of the pump shaft. 

The impellers used on centrifugal pumps may be classified as SINGLE SUCTION or DOUBLE 

SUCTION. The single-suction impeller allows liquid to enter the eye from one side only. The 

double-suction impeller allows liquid to enter the eye from two directions. 

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Impellers are also classified as CLOSED or OPEN. Closed impellers have side walls that extend 

from the eye to the outer edge of the vane tips. Open impellers do not have these side walls. 

Some small pumps with single-suction impellers have only a casing wearing ring and no 

impeller ring. In this type of pump, the casing wearing ring is fitted into the end plate. 

Recirculation lines are installed on some centrifugal pumps to prevent the pumps from 

overheating and becoming vapor bound, in case the discharge is entirely shut off or the flow of 

fluid is stopped for extended periods. 

Seal piping is installed to cool the shaft and the packing, to lubricate the packing, and to seal the 

rotating joint between the shaft and the packing against air leakage. A lantern ring spacer is 

inserted between the rings of the packing in the stuffing box. 

Seal piping leads the liquid from the discharge side of the pump to the annular space formed by 

the lantern ring. The web of the ring is perforated so that the water can flow in either direction 

along the shaft (between the shaft and the packing). 

Water flinger rings are fitted on the shaft between the packing gland and the pump bearing 

housing. These flingers prevent water in the stuffing box from flowing along the shaft and 

entering the bearing housing. 

Look at the components of the centrifugal pump. 

Centrifugal Pump 

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As the impeller rotates, it sucks the liquid into the center of the pump and throws it out under 

pressure through the outlet. The casing that houses the impeller is referred to as the volute, the 

impeller fits on the shaft inside. The volute has an inlet and outlet that carries the water as 

shown above. 

These pictures illustrate the components that are common to most pump assemblies. 

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NPSH - Net Positive Suction Head 

If you accept that a pump creates a partial vacuum and atmospheric pressure forces water into 

the suction of the pump, then you will find NPSH a simple concept. 

NPSH (a) is the Net Positive Suction Head Available, which is calculated as follows: 

NPSH (a) = p + s - v - f 

Where: 

'p'= atmospheric pressure, 

's'= static suction (If liquid is below pump, it is shown as a negative value) 

'v'= liquid vapor pressure 

'f'= friction loss 

NPSH (a) must exceed NPSH(r) to allow pump operation without cavitation. (It is advisable to 

allow approximately 1 meter difference for most installations.) The other important fact to 

remember is that water will boil at much less than 100 deg C O if the pressure acting on it is less 

than its vapor pressure, i.e. water at 95 deg C is just hot water at sea level, but at 1500m above 

sea level it is boiling water and vapor. 

The vapor pressure of water at 95 deg C is 84.53 kPa, there was enough atmospheric pressure 

at sea level to contain the vapor, but once the atmospheric pressure dropped at the higher 

elevation, the vapor was able to escape. This is why vapor pressure is always considered in 

NPSH calculations when temperatures exceed 30 to 40 deg C. 

NPSH(r) is the Net Positive Suction Head Required by the pump, which is read from the pump 

performance curve. (Think of NPSH(r) as friction loss caused by the entry to the pump suction.) 

Affinity Laws 

The Centrifugal Pump is a very capable and flexible machine. Because of this it is unnecessary 

to design a separate pump for each job. The performance of a centrifugal pump can be varied 

by changing the impeller diameter or its rotational speed. Either change produces approximately 

the same results. Reducing impeller diameter is probably the most common change and is 

usually the most economical. The speed can be altered by changing pulley diameters or by 

changing the speed of the driver. In some cases both speed and impeller diameter are changed 

to obtain the desired results. 

When the driven speed or impeller diameter of a centrifugal pump changes, operation of the 

pump changes in accordance with three fundamental laws. These laws are known as the "Laws 

of Affinity". They state that: 

1) Capacity varies directly as the change in speed 

2) Head varies as the square of the change in speed 

3) Brake horsepower varies as the cube of the change in speed 

If, for example, the pump speed were doubled: 

1) Capacity will double 

2) Head will increase by a factor of 4 (2 to the second power) 

3) Brake horsepower will increase by a factor of 8 (2 to the third power) 

These principles apply regardless of the direction (up or down) of the speed or change in 

diameter. 

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Consider the following example. A pump operating at 1750 RPM, delivers 210 GPM at 75' TDH, 

and requires 5.2 brake horsepower. What will happen if the speed is increased to 2000 RPM? 

First we find the speed ratio. 

Speed Ratio = 2000/1750 = 1.14 

From the laws of Affinity: 

1) Capacity varies directly or: 

1.14 X 210 GPM = 240 GPM 

2) Head varies as the square or: 

1.14 X 1.14 X 75 = 97.5' TDH 

3) BHP varies as the cube or: 

1.14 X 1.14 X 1.14 X 5.2 = 7.72 BHP 

Theoretically the efficiency is the same for both conditions. By calculating several points a new 

curve can be drawn. 

Whether it be a speed change or change in impeller diameter, the Laws of Affinity give results 

that are approximate. The discrepancy between the calculated values and the actual values 

obtained in test are due to hydraulic efficiency changes that result from the modification. The 

Laws of Affinity give reasonably close results when the changes are not more than 50% of the 

original speed or 15% of the original diameter. 

Suction conditions are some of the most important factors affecting centrifugal pump operation. 

If they are ignored during the design or installation stages of an application, they will probably 

come back to haunt you. 

Suction Lift 

A pump cannot pull or "suck" a liquid up its suction pipe because liquids do not exhibit tensile 

strength. Therefore, they cannot transmit tension or be pulled. When a pump creates a suction, 

it is simply reducing local pressure by creating a partial vacuum. Atmospheric or some other 

external pressure acting on the surface of the liquid pushes the liquid up the suction pipe into 

the pump. 

Atmospheric pressure at sea level is called absolute pressure (PSIA) because it is a 

measurement using absolute zero (a perfect vacuum) as a base. If pressure is measured using 

atmospheric pressure as a base it is called gauge pressure (PSIG or simply PSI). 

Atmospheric pressure, as measured at sea level, is 14.7 PSIA. In feet of head it is: 

Head = PSI X 2.31 / Specific Gravity 

For Water it is: 

Head = 14.7 X 2.31 / 1.0 = 34 Ft 

Thus, 34 feet is the theoretical maximum suction lift for a pump pumping cold water at sea level. 

No pump can attain a suction lift of 34 ft; however, well designed ones can reach 25 ft quite 

easily. You will note, from the equation above, that specific gravity can have a major effect on 

suction lift. For example, the theoretical maximum lift for brine (Specific Gravity = 1.2) at sea 

level is 28 ft.. The realistic maximum is around 20ft. Remember to always factor in specific 

gravity if the liquid being pumped is anything but clear, cold (68 degrees F) water. 

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In addition to pump design and suction piping, there are two physical properties of the liquid 

being pumped that affect suction lift. 

1) Maximum suction lift is dependent upon the pressure applied to the surface of the liquid at 

the suction source. Maximum suction lift decreases as pressure decreases. 

2) 2) Maximum suction lift is dependent upon the vapor pressure of the liquid being pumped. 

The vapor pressure of a liquid is the pressure necessary to keep the liquid from vaporizing 

(boiling) at a given temperature. Vapor pressure increases as liquid temperature increases. 

Maximum suction lift decreases as vapor pressure rises. 

It follows then, that the maximum suction lift of a centrifugal pump varies inversely with altitude. 

Conversely, maximum suction lift will increase as the external pressure on its source increases 

(for example: a closed pressure vessel). 

Cavitation - Two Main Causes: 

A. NPSH (r) EXCEEDS NPSH (a) 

Due to low pressure the water vaporizes (boils), and higher pressure implodes into the vapor 

bubbles as they pass through the pump, causing reduced performance and potentially major 

damage. 

B. Suction or discharge recirculation. The pump is designed for a certain flow range, if there is 

not enough or too much flow going through the pump, the resulting turbulence and vortexes can 

reduce performance and damage the pump. 

Affinity Laws - Centrifugal Pumps 

If the speed or impeller diameter of a pump changes, we can calculate the resulting 

performance change using: 

Affinity laws 

a. The flow changes proportionally to speed 

i.e.: double the speed / double the flow 

b. The pressure changes by the square of the difference 

i.e.: double the speed / multiply the pressure by 4 

c. The power changes by the cube of the difference 

i.e.: double the speed / multiply the power by 8 

Notes: 

1. These laws apply to operating points at the same efficiency. 

2. Variations in impeller diameter greater than 10% are hard to predict due to the change in 

relationship between the impeller and the casing. For rough calculations you can adjust a duty 

point or performance curve to suit a different speed. NPSH (r) is affected by speed / impeller 

diameter change = DANGER ! 

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Pump Casing 

There are many variations of centrifugal pumps. The most common type is an end suction 

pump. Another type of pump used is the split case. There are many variations of split case, 

such as; two-stage, single suction, and double suction. Most of these pumps are horizontal. 

There are variations of vertical centrifugal pumps. The line shaft turbine is really a multistage 

centrifugal pump. 

Impeller 

In most centrifugal pumps, the impeller looks like a number of cupped vanes on blades mounted 

on a disc or shaft. Notice in the picture below how the vanes of the impeller force the water into 

the outlet of the pipe. 

The shape of the vanes of the impeller is important. As the water is 

being thrown out of the pump, this means you can run centrifugal 

pumps with the discharged valve closed for a SHORT period of 

time. Remember the motor sends energy along the shaft, and if the 

water is in the volute too long it will heat up and create steam. Not 

good! 

Impellers are designed in various ways. We will look at: 

� Closed impellers 

� Semi-open impellers 

� Opened impellers, and 

� Recessed impellers 

The impellers all cause a flow from the eye of the impeller to 

the outside of the impeller. These impellers cause what is 

called radial flow, and they can be referred to as radial flow 

impellers. 

The critical distance of the impeller and how it is installed in 

the casing will determine if it is high volume / low pressure or 

the type of liquid that could be pumped. 

Axial flow impellers look like a propeller and create a flow 

that is parallel to the shaft. 

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Pump Performance and Curves 

Let’s looks at the big picture. Before you make that purchase of the pump and motor you need 

to know the basics such as: 

� Total dynamic head, the travel distance 

� Capacity, how much water you need to provide 

� Efficiency, help determine the impeller size 

� HP, how many squirrels you need 

� RPM, how fast the squirrels run 

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Motor and Pump Calculations 

The centrifugal pump pumps the difference between the suction and the discharge heads. 

There are three kinds of discharge head: 

� Static head. The height we are pumping to, or the height to the discharge piping outlet 

that is filling the tank from the top. Note: that if you are filling the tank from the bottom, 

the static head will be constantly changing. 

� Pressure head. If we are pumping to a pressurized vessel (like a boiler) we must 

convert the pressure units (psi. or Kg.) to head units (feet or meters). 

� System or dynamic head. Caused by friction in the pipes, fittings, and system 

components. We get this number by making the calculations from published charts. 

Suction head is measured the same way. 

� If the liquid level is above the pump center line, that level is a positive suction head. If 

the pump is lifting a liquid level from below its center line, it is a negative suction head. 

� If the pump is pumping liquid from a pressurized vessel, you must convert this pressure 

to a positive suction head. A vacuum in the tank would be converted to a negative 

suction head. 

� Friction in the pipes, fittings, and associated hardware is a negative suction head. 

� Negative suction heads are added to the pump discharge head, positive suctions heads 

are subtracted from the pump discharge head. 

Total Dynamic Head (TDH) is the total height that a fluid is to be pumped, taking into account 

friction losses in the pipe. 

TDH = Static Lift + Static Height + Friction Loss 

where: 

Static Lift is the height the water will rise before arriving at the pump (also known as the 'suction 

head'). 

Static Height is the maximum height reached by the pipe after the pump (also known as the 

'discharge head'). 

Friction Loss is the head equivalent to the energy losses due to viscose drag of fluid flowing in 

the pipe (both on the suction and discharge sides of the pump). It is calculated via a formula or 

a chart, taking into account the pipe diameter and roughness and the fluid flow rate, density, 

and viscosity. 

Motor hp Brake hp Water hp 

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Horsepower 

Work involves the operation of force over a specific distance. The rate of doing work is called 

power. 

The rate in which a horse could work was determined to be about 550 ft-lbs/sec or 33,000 ftlbs/min. 

1 hp = 33,000 ft-lbs/min 

Motor Horsepower (mhp) 

1 hp = 746 watts or .746 Kilowatts 

MHP refers to the horsepower supplied in the form of electrical current. The efficiency of most 

motors range from 80-95%. (Manufactures will list efficiency %) 

Brake Horsepower (bhp) 

Water hp 

Brake hp = --------------- 

Pump Efficiency 

BHP refers to the horsepower supplied to the pump from the motor. As the power moves 

through the pump, additional horsepower is lost, resulting from slippage and friction of the shaft 

and other factors. 

Water Horsepower 

(flow gpm)(total hd) 

Water hp = --------------------------- 

3960 

Water horsepower refers to the actual horse power available to pump the water. 

Horsepower and Specific Gravity 

The specific gravity of a liquid is an indication of its density or weight compared to water. The 

difference in specific gravity, include it when calculating ft-lbs/min pumping requirements. 

(ft)(lbs/min)(sp.gr.) 

------------------------- = whp 

33,000 ft-lbs/min/hp 

MHP and Kilowatt requirements 

1 hp = 0.746 kW or (hp) (746 watts/hp) 

------------------------ 

1000 watts/kW 

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Well Calculations 

1. Well drawdown 

Drawdown ft = Pumping water level, ft - Static water level, ft 

2. Well yield 

Flow, gallons 

Well yield, gpm = ----------------------- 

Duration of test, min 

3. Specific yield 

Well yield, gpm 

Specific yield, gpm/ft = --------------------- 

Drawdown, ft 

4. Deep well turbine pump calculations. 

Discharge head, ft = (pressure measured) ( 2.31 ft/psi) 

Field head, ft = pumping water + discharge head, ft 

Bowl head, ft = field head + column friction 

1 psi = 2.31 feet of head 

1 foot of head = .433 psi 

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Example 1 

A centrifugal pump is located at an elevation of 722 ft. This pump is used to move water from 

reservoir A to reservoir B. The water level in reservoir A is 742 ft and the water level in reservoir 

B is 927 ft. Based on these conditions answer the following questions: 

1. If the pump is not running and pressure gauges are installed on the suction and 

discharge lines, what pressures would the gauges read? 

Suction side: 

Discharge side: 

2. How can you tell if this is a suction head condition? 

3. Calculate the following head measurements: 

SSH: 

SDH: 

TSH: 

4. Convert the pressure gauge readings to feet: 

6 psi: 

48 psi: 

110 psi: 

5. Calculate the following head in feet to psi: 

20 ft: 

205 ft: 

185 ft: 

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Motor, Coupling and Bearing Section 

We will now refer to the motor, coupling, and bearings. The power source of the pump is usually 

an electric motor. The motor is connected by a coupling to the pump shaft. The purpose of the 

bearings is to hold the shaft firmly in place, yet allow it to rotate. The bearing house supports the 

bearings and provides a reservoir for the lubricant. An impeller is connected to the shaft. The 

pump assembly can be a vertical or horizontal set-up; the components for both are basically the 

same. 

Motors 

The purpose of this discussion on pump motors is to identify and describe the main types of 

motors, starters, enclosures, and motor controls, as well as to provide you with some basic 

maintenance and troubleshooting information. Although pumps could be driven by diesel or 

gasoline engines, pumps driven by electric motors are commonly used in our industry. 

There are two general categories of electric motors: 

� D-C motors, or direct current 

� A-C motors, or alternating current 

You can expect most motors at facilities 

to be A-C type. 

D-C Motors 

The important characteristic of the D-C 

motor is that its speed will vary with the 

amount of current used. There are many 

different kinds of D-C motors, depending 

on how they are wound and their 

speed/torque characteristics. 

A-C Motors 

There are a number of different types of 

alternating current motors, such as Synchronous, Induction, wound rotor, and squirrel cage. The 

synchronous type of A-C motor requires complex control equipment, since they use a 

combination of A-C and D-C. This also means that the synchronous type of A-C motor is used in 

large horsepower sizes, usually above 250 HP. The induction type motor uses only alternating 

current. The squirrel cage motor provides a relatively constant speed. The wound rotor type 

could be used as a variable speed motor. 

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Define the Following Terms: 

Voltage: 

EMF: 

Power: 

Current: 

Resistance: 

Conductor: 

Phase: 

Single Phase: 

Three Phase: 

Hertz: 

Motor Starters 

All electric motors, except very small ones such as chemical feed pumps, are equipped with 

starters, either full voltage or reduced voltage. This is because motors draw a much higher 

current when they are starting and gaining speed. The purpose of the reduced voltage starter is 

to prevent the load from coming on until the amperage is low enough. 

How do you think keeping the discharge valve closed on a 

centrifugal pump could reduce the startup load? 

Motor Enclosures 

Depending on the application, motors may need special 

protection. Some motors are referred to as open motors. 

They allow air to pass through to remove heat generated 

when current passes through the windings. Other motors 

use specific enclosures for special environments or safety 

protection. 

Can you think of any locations within your facility that requires special enclosures? 

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Two Types of Totally Enclosed Motors Commonly Used are: 

� TENV, or totally enclosed non-ventilated motor 

� TEFC, or totally enclosed fan cooled motor 

Totally enclosed motors include dust-proof, water-proof and explosion-proof motors. An 

explosion proof enclosure must be provided on any motor where dangerous gases might 

accumulate. 

Motor Controls 

All pump motors are provided with some method of control, typically a combination of manual 

and automatic. Manual pump controls can be located at the central control panel at the pump or 

at the suction or discharge points of the liquid being pumped. 

There are a number of ways in which automatic control of a pump motor can be regulated: 

� Pressure and vacuum sensors 

� Preset time intervals 

� Flow sensors 

� Level sensors 

Two typical level sensors are the float 

sensor and the bubble regulator. The 

float sensor is pear-shaped and hangs 

in the wet well. As the height increases, 

the float tilts, and the mercury in the 

glass tube flows toward the end of the 

tube that has two wires attached to it. 

When the mercury covers the wires, it 

closes the circuit. 

A low pressure air supply is allowed to 

escape from a bubbler pipe in the wet well. The back-pressure on the air supply will vary with 

the liquid level over the pipe. Sensitive air pressure switches will detect this change and use this 

information to control pump operation. 

Motor Maintenance 

Motors should be kept clean, free of 

moisture, and lubricated properly. Dirt, 

dust, and grime will plug the ventilating 

spaces and can actually form an 

insulating layer over the metal surface of 

the motor. 

What condition would occur if the 

ventilation becomes blocked? 

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Moisture 

Moisture harms the insulation on the windings to the point where they may no longer provide the 

required insulation for the voltage applied to the motor. In addition, moisture on windings tend to 

absorb acid and alkali fumes, causing damage to both insulation and metals. To reduce 

problems caused by moisture, the most suitable motor enclosure for the existing environment 

will normally be used. It is recommended to run stand by motors to dry up any condensation 

which accumulates in the motor. 

Motor Lubrication 

Friction will cause wear in all moving parts, and lubrication is needed to reduce this friction. It is 

very important that all your manufacturer's recommended lubrication procedures are strictly 

followed. You have to be careful not to add too much grease or oil, as this could cause more 

friction and generate heat. 

To grease the motor bearings, this is the usual approach: 

1. Remove the protective plugs and caps from the grease inlet and relief holes. 

2. Pump grease in until fresh starts coming from the relief hole. 

If fresh grease does not come out of the relief hole, this could mean that the grease has been 

pumped into the motor windings. The motor must then be taken apart and cleaned by a qualified 

service representative. 

To change the oil in an oil lubricated motor, this is the usual approach: 

1. Remove all plugs and let the oil drain. 

2. Check for metal shearing. 

3. Replace the oil drain. 

4. Add new oil until it is up to the oil level plug. 

5. Replace the oil level and filter plug. 

Never mix oils, since the additives of different oils when combined can cause breakdown of the 

oil. 

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More Detailed Information on Motors 

The classic division of electric motors has been that of Direct Current (DC) types vs. Alternating 

Current (AC) types. This is more a de facto convention, rather than a rigid distinction. For 

example, many classic DC motors run happily on AC power. 

The ongoing trend toward electronic control further muddles the distinction, as modern drivers 

have moved the commutator out of the motor shell. For this new breed of motor, driver circuits 

are relied upon to generate sinusoidal AC drive currents, or some approximation of. The two 

best examples are: the brushless DC motor and the stepping motor, both being polyphase AC 

motors requiring external electronic control. 

There is a clearer distinction between a synchronous motor and asynchronous types. In the 

synchronous types, the rotor rotates in synchrony with the oscillating field or current (e.g. 

permanent magnet motors). In contrast, an asynchronous motor is designed to slip; the most 

ubiquitous example being the common AC induction motor which must slip in order to generate 

torque. 

A DC motor is designed to run on DC electric power. Two examples of pure DC designs are 

Michael Faraday's homopolar motor (which is uncommon), and the ball bearing motor, which is 

(so far) a novelty. By far the most common DC motor types are the brushed and brushless 

types, which use internal and external commutation respectively to create an oscillating AC 

current from the DC source -- so they are not purely DC machines in a strict sense. 

Brushed DC motors 

The classic DC motor design generates an oscillating current in a wound rotor with a split ring 

commutator, and either a wound or permanent magnet stator. A rotor consists of a coil wound 

around a rotor, which is then powered by any type of battery. Many of the limitations of the 

classic commutator DC motor are due to the need for brushes to press against the commutator. 

This creates friction. At higher speeds, brushes have increasing difficulty in maintaining contact. 

Brushes may bounce off the irregularities in the commutator surface, creating sparks. This limits 

the maximum speed of the machine. 

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The current density per unit area of the brushes limits the output of the motor. The imperfect 

electric contact also causes electrical noise. Brushes eventually wear out and require 

replacement, and the commutator itself is subject to wear and maintenance. The commutator 

assembly on a large machine is a costly element, requiring precision assembly of many parts. 

Brushless DC motors 

Some of the problems of the brushed DC motor are eliminated in the brushless design. In this 

motor, the mechanical "rotating switch" or commutator/brush gear assembly is replaced by an 

external electronic switch synchronized to the rotor's position. Brushless motors are typically 85- 

90% efficient, whereas DC motors with brush gear are typically 75-80% efficient. 

Midway between ordinary DC motors and stepper motors lies the realm of the brushless DC 

motor. Built in a fashion very similar to stepper motors, these often use a permanent magnet 

external rotor, three phases of driving coils, one or more Hall effect sensors to sense the 

position of the rotor, and the associated drive electronics. 

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The coils are activated one phase after the other by the drive electronics, as cued by the signals 

from the Hall effect sensors. In effect, they act as three-phase synchronous motors containing 

their own variable-frequency drive electronics. Brushless DC motors are commonly used where 

precise speed control is necessary, as in computer disk drives or in video cassette recorders, 

the spindles within CD, CD-ROM (etc.) drives, and mechanisms within office products such as 

fans, laser printers ,and photocopiers. 

They have several advantages over conventional motors: 

* Compared to AC fans using shaded-pole motors, they are very efficient, running much cooler 

than the equivalent AC motors. This cool operation leads to much-improved life of the fan's 

bearings. 

* Without a commutator to wear out, the life of a DC brushless motor can be significantly longer 

compared to a DC motor using brushes and a commutator. Commutation also tends to cause a 

great deal of electrical and RF noise; without a commutator or brushes, a brushless motor may 

be used in electrically sensitive devices like audio equipment or computers. 

* The same Hall Effect sensors that provide the commutation can also provide a convenient 

tachometer signal for closed-loop control (servo-controlled) applications. In fans, the tachometer 

signal can be used to derive a "fan OK" signal. 

* The motor can be easily synchronized to an internal or external clock, leading to precise speed 

control. 

* Brushless motors have no chance of sparking, unlike brushed motors, making them better 

suited to environments with volatile chemicals and fuels. 

* Brushless motors are usually used in small equipment such as computers, and are generally 

used to get rid of unwanted heat. 

* They are also very quiet motors, which is an advantage if being used in equipment that is 

affected by vibrations. 

Modern DC brushless motors range in power from a fraction of a watt to many kilowatts. Larger 

brushless motors up to about 100 kW rating are used in electric vehicles. They also find 

significant use in high-performance electric model aircraft. 

Coreless DC Motors 

Nothing in the design of any of the motors described above requires that the iron (steel) portions 

of the rotor actually rotate; torque is exerted only on the windings of the electromagnets. Taking 

advantage of this fact is the coreless DC motor, a specialized form of a brush or brushless DC 

motor. Optimized for rapid acceleration, these motors have a rotor that is constructed without 

any iron core. The rotor can take the form of a winding-filled cylinder inside the stator magnets, 

a basket surrounding the stator magnets, or a flat pancake (possibly formed on a printed wiring 

board) running between upper and lower stator magnets. The windings are typically stabilized 

by being impregnated with electrical epoxy potting systems. Filled epoxies that have moderate 

mixed viscosity and a long gel time. These systems are highlighted by low shrinkage and low 

exotherm. 

Because the rotor is much lighter in weight (mass) than a conventional rotor formed from copper 

windings on steel laminations, the rotor can accelerate much more rapidly, often achieving a 

mechanical time constant under 1 ms. This is especially true if the windings use aluminum 

rather than the heavier copper. But because there is no metal mass in the rotor to act as a heat 

sink, even small coreless motors must often be cooled by forced air. 

These motors were commonly used to drive the capstan(s) of magnetic tape drives and are still 

widely used in high-performance servo-controlled systems, like radio-controlled vehicles/aircraft, 

humanoid robotic systems, industrial automation, medical devices, etc. 

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Universal Motors 

A variant of the wound field DC motor is the universal motor. The name derives from the fact 

that it may use AC or DC supply current, although in practice they are nearly always used with 

AC supplies. The principle is that in a wound field DC motor the current in both the field and the 

armature (and hence the resultant magnetic fields) will alternate (reverse polarity) at the same 

time, and hence the mechanical force generated is always in the same direction. In practice, the 

motor must be specially designed to cope with the AC current (impedance must be taken into 

account, as must the pulsating force), and the resultant motor is generally less efficient than an 

equivalent pure DC motor. Operating at normal power line frequencies, the maximum output of 

universal motors is limited and motors exceeding one kilowatt are rare. But universal motors 

also form the basis of the traditional railway traction motor in electric railways. In this application, 

to keep their electrical efficiency high, they were operated from very low frequency AC supplies, 

with 25 Hz and 16 2/3 hertz operation being common. Because they are universal motors, 

locomotives using this design were also commonly capable of operating from a third rail 

powered by DC. 

The advantage of the universal motor is that AC supplies may be used on motors which have 

the typical characteristics of DC motors, specifically high starting torque and very compact 

design if high running speeds are used. The negative aspect is the maintenance and short life 

problems caused by the commutator. As a result, such motors are usually used in AC devices 

such as food mixers and power tools, which are used only intermittently. 

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Continuous speed control of a universal motor running on AC is very easily accomplished using 

a thyristor circuit, while stepped speed control can be accomplished using multiple taps on the 

field coil. Household blenders that advertise many speeds frequently combine a field coil with 

several taps and a diode that can be inserted in series with the motor (causing the motor to run 

on half-wave rectified AC). 

Universal motors can rotate at relatively high revolutions per minute (rpm). This makes them 

useful for appliances such as blenders, vacuum cleaners, and hair dryers where high-speed 

operation is desired. Many vacuum cleaner and weed trimmer motors exceed 10,000 rpm; 

Dremel and other similar miniature grinders will often exceed 30,000 rpm. Motor damage may 

occur due to overspeed (rpm in excess of design specifications) if the unit is operated with no 

significant load. On larger motors, sudden loss of load is to be avoided, and the possibility of 

such an occurrence is incorporated into the motor's protection and control schemes. Often, a 

small fan blade attached to the armature acts as an artificial load to limit the motor speed to a 

safe value, as well as provide cooling airflow to the armature and field windings. 

With the very low cost of semiconductor rectifiers, some applications that would have previously 

used a universal motor now use a pure DC motor, sometimes with a permanent magnet field. 

AC Motors 

In 1882, Nicola Tesla identified the rotating magnetic field principle, and pioneered the use of a 

rotary field of force to operate machines. He exploited the principle to design a unique twophase 

induction motor in 1883. In 1885, Galileo Ferraris independently researched the concept. 

In 1888, Ferraris published his research in a paper to the Royal Academy of Sciences in Turin. 

Introduction of Tesla's motor from 1888 onwards initiated what is sometimes referred to as the 

Second Industrial Revolution, making possible the efficient generation and long distance 

distribution of electrical energy using the alternating current transmission system, also of Tesla's 

invention (1888). Before the invention of the rotating magnetic field, motors operated by 

continually passing a conductor through a stationary magnetic field (as in homopolar motors). 

Tesla had suggested that the commutators from a machine could be removed and the device 

could operate on a rotary field of force. Professor Poeschel, his teacher, stated that would be 

akin to building a perpetual motion machine. 

Components 

A typical AC motor consists of two parts: 

1. An outside stationary stator having coils supplied with AC current to produce a rotating 

magnetic field, and; 

2. An inside rotor attached to the output shaft that is given a torque by the rotating field. 

Torque Motors 

A torque motor is a specialized form of induction motor which is capable of operating indefinitely 

at stall (with the rotor blocked from turning) without damage. In this mode, the motor will apply a 

steady stall torque to the load (hence the name). A common application of a torque motor would 

be the supply- and take-up reel motors in a tape drive. In this application, driven from a low 

voltage, the characteristics of these motors allow a relatively-constant light tension to be applied 

to the tape whether or not the capstan is feeding tape past the tape heads. Driven from a higher 

voltage, (and so delivering a higher torque), the torque motors can also achieve fast-forward 

and rewind operation without requiring any additional mechanics such as gears or clutches. In 

the computer world, torque motors are used with force feedback steering wheels. 

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Slip Ring 

The slip ring or wound rotor motor is an induction machine where the rotor comprises a set of 

coils that are terminated in slip rings to which external impedances can be connected. The 

stator is the same as is used with a standard squirrel cage motor. By changing the impedance 

connected to the rotor circuit, the speed/current and speed/torque curves can be altered. 

The slip ring motor is used primarily to start a high inertia load or a load that requires a very high 

starting torque across the full speed range. By correctly selecting the resistors used in the 

secondary resistance or slip ring starter, the motor is able to produce maximum torque at a 

relatively low current from zero speed to full speed. A secondary use of the slip ring motor is to 

provide a means of speed control. 

Because the torque curve of the motor is effectively modified by the resistance connected to the 

rotor circuit, the speed of the motor can be altered. Increasing the value of resistance on the 

rotor circuit will move the speed of maximum torque down. If the resistance connected to the 

rotor is increased beyond the point where the maximum torque occurs at zero speed, the torque 

will be further reduced. When used with a load that has a torque curve that increases with 

speed, the motor will operate at the speed where the torque developed by the motor is equal to 

the load torque. Reducing the load will cause the motor to speed up, and increasing the load will 

cause the motor to slow down until the load and motor torque are equal. Operated in this 

manner, the slip losses are dissipated in the secondary resistors and can be very significant. 

The speed regulation is also very poor. 

Stepper Motors 

Closely related in design to three-phase AC synchronous motors are stepper motors, where an 

internal rotor containing permanent magnets or a large iron core with salient poles is controlled 

by a set of external magnets that are switched electronically. A stepper motor may also be 

thought of as a cross between a DC electric motor and a solenoid. As each coil is energized in 

turn, the rotor aligns itself with the magnetic field produced by the energized field winding. 

Unlike a synchronous motor, in its application, the motor may not rotate continuously; instead, it 

"steps" from one position to the next as field windings are energized and de-energized in 

sequence. Depending on the sequence, the rotor may turn forwards or backwards. 

Simple stepper motor drivers entirely energize or entirely de-energize the field windings, leading 

the rotor to "cog" to a limited number of positions; more sophisticated drivers can proportionally 

control the power to the field windings, allowing the rotors to position between the cog points 

and thereby rotate extremely smoothly. Computer controlled stepper motors are one of the most 

versatile forms of positioning systems, particularly when part of a digital servo-controlled 

system. 

Stepper motors can be rotated to a specific angle with ease, and hence stepper motors are 

used in pre-gigabyte era computer disk drives, where the precision they offered was adequate 

for the correct positioning of the read/write head of a hard disk drive. As drive density increased, 

the precision limitations of stepper motors made them obsolete for hard drives, thus newer hard 

disk drives use read/write head control systems based on voice coils. Stepper motors were upscaled 

to be used in electric vehicles under the term SRM (switched reluctance machine). 

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Coupling Section 

The pump coupling serves two main purposes: 

� It couples or joins the two shafts together to transfer the rotation from motor to impeller. 

� It compensates for small amounts of misalignment between the pump and the motor. 

Remember that any coupling is a device in motion. If you have a 4-inch diameter coupling 

rotating at 1800 rpm, its outer surface is traveling about 20 mph. With that in mind, can you think 

of safety considerations? 

There are three commonly used types of couplings: Rigid, Flexible and V-belts. 

Rigid Coupling 

Rigid couplings are most commonly used on vertically mounted pumps. The rigid coupling is 

usually specially keyed or constructed for joining the coupling to the motor shaft and the pump 

shaft. There are two types of rigid couplings: the flanged coupling, and the split coupling. 

Flexible Coupling. The flexible coupling provides the ability to compensate for small shaft 

misalignments. Shafts should be aligned as close as possible, regardless. The greater the 

misalignment, the shorter the life of the coupling. Bearing wear and life are also affected by 

misalignment. 

1. Oil Seals 

2. Large Oil Sump 

3. Bulls Eye Sight Glass 

4. Rigid Frame Foot 

5. C-Face Mounting Flange 

6. Lubrication Flexibility 

7. Condition Monitoring Sites 

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Alignment of Flexible and Rigid Couplings 

Both flexible and rigid couplings must be carefully aligned before they are connected. 

Misalignment will cause excessive heat and vibration, as well as bearing wear. Usually, the 

noise from the coupling will warn you of shaft misalignment problems. 

Three types of shaft alignment problems are shown in the pictures below: 

ANGULAR MISALIGNMENT ANGULAR AND PARALLEL PARALLEL MISALIGNMENT 

Different couplings will require different alignment procedures. We will look at the general 

procedures for aligning shafts. 

1. Place the coupling on each shaft. 

2. Arrange the units so they appear to be aligned. (Place shims under the legs of one of the 

units to raise it.) 

3. Check the run-out, or difference between the driver and driven unit, by rotating the shafts 

by hand. 

4. Turn both units so that the maximum run-out is on top. 

Now you can check the units for both parallel and angular alignment. Many techniques are 

used, such as: straight edge, needle deflection (dial indicators), calipers, tapered wedges, and 

laser alignment. 

V-Belt Drive Couplings 

V-belt drives connect the pump to the motor. A pulley is mounted on the pump and motor shaft. 

One or more belts are used to connect the two pulleys. Sometimes a separately mounted third 

pulley is used. This idler pulley is located off centerline between the two pulleys, just enough to 

allow tensioning of the belts by moving the idler pulley. An advantage of driving a pump with 

belts is that various speed ratios can be achieved between the motor and the pump. 

Shaft Bearings 

There are three types of bearings commonly used: ball bearings, roller bearings, and sleeve 

bearings. Regardless of the particular type of bearings used within a system--whether it is ball 

bearings, a sleeve bearing, or a roller bearing--the bearings are designed to carry the loads 

imposed on the shaft. 

Bearings must be lubricated. Without proper lubrication, bearings will overheat and seize. 

Proper lubrication means using the correct type and the correct amount of lubrication. Similar to 

motor bearings, shaft bearings can be lubricated either by oil or by grease. 

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How can we prevent the water from leaking along the shaft? 

A special seal is used to prevent liquid leaking out along the shaft. There are two types of seals 

commonly used: 

� Packing seal 

� Mechanical seal 

Packing Seals 

Should packing have leakage? 

Leakage 

During pump operation, a certain amount of 

leakage around the shafts and casings 

normally takes place. 

This leakage must be controlled for two 

reasons: (1) to prevent excessive fluid loss from the pump, and (2) to prevent air from entering 

the area where the pump suction pressure is below atmospheric pressure. 

The amount of leakage that can occur without limiting pump efficiency determines the type of 

shaft sealing selected. Shaft sealing systems are found in every pump. They can vary from 

simple packing to complicated sealing systems. 

Packing is the most common and oldest method of sealing. Leakage is checked by the 

compression of packing rings that causes the rings to deform and seal around the pump shaft 

and casing. The packing is lubricated by liquid moving through a lantern ring in the center of the 

packing. The sealing slows down the rate of leakage. It does not stop it completely, since a 

certain amount of leakage is necessary during operation. Mechanical seals are rapidly replacing 

conventional packing on centrifugal pumps. 

Some of the reasons for the use of mechanical seals are as follows: 

1. Leaking causes bearing failure by contaminating the oil with water. This is a major problem in 

engine-mounted water pumps. 

2. Properly installed mechanical seals eliminate leakoff on idle (vertical) pumps. This design 

prevents the leak (water) from bypassing the water flinger and entering the lower bearings. 

Leakoff causes two types of seal leakage: 

a. Water contamination of the engine lubrication oil. 

b. Loss of treated fresh water that causes scale buildup in the cooling system. 

Centrifugal pumps are versatile and have many uses. This type of pump is commonly used to 

pump all types of water and wastewater flows, including thin sludge. 

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Lantern Rings 

Lantern rings are used to supply clean water along the shaft. This helps to prevent grit and air 

from reaching the area. Another component is the slinger ring. The slinger ring is an important 

part of the pump because it is used to protect the bearings. Other materials can be used to 

prevent this burier. 

Mechanical Seals 

Mechanical seals are commonly used to reduce leakage 

around the pump shaft. There are many types of mechanical 

seals. The photograph below illustrates the basic 

components of a mechanical seal. Similar to the packing 

seal, clean water is fed at a pressure greater than that of the 

liquid being pumped. There is little or no leakage through the 

mechanical seal. The wearing surface must be kept 

extremely clean. Even fingerprints on the wearing surface 

can introduce enough dirt to cause problems. 

What care should be taken when storing mechanical seals? 


Wear Rings 

Not all pumps have wear rings. However, when they are included, they are usually replaceable. 

Wear rings can be located on the suctions side and head side of the volute. Wear rings could be 

made of the same metal but of different alloys. The wear ring on the head side is usually a 

harder alloy. 

It’s called a “WEAR RING” and what would be the purpose? 

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Mechanical seals are rapidly replacing conventional packing as the means of controlling 

leakage on rotary and positive-displacement pumps. Mechanical seals eliminate the problem of 

excessive stuffing box leakage, which causes failure of pump and motor bearings and motor 

windings. 

Mechanical seals are ideal for pumps that operate in closed systems (such as fuel service and 

air-conditioning, chilled-water, and various cooling systems). They not only conserve the fluid 

being pumped, but also improve system operation. 

The type of material used for the seal faces will depend upon the service of the pump. Most 

water service pumps use a carbon material for one of the seal faces and ceramic (tungsten 

carbide) for the other. When the seals wear out, they are simply replaced. 

You should replace a mechanical seal whenever the seal is removed from the shaft for any 

reason, or whenever leakage causes undesirable effects on equipment or surrounding spaces. 

Do not touch a new seal on the sealing face because body acid and grease or dirt will cause the 

seal to pit prematurely and leak. 

Mechanical shaft seals are positioned on the shaft by stub or step sleeves. Mechanical shaft 

seals must not be positioned by setscrews. Shaft sleeves are chamfered (beveled) on the 

outboard ends for easy mechanical seal mounting. Mechanical shaft seals serve to ensure that 

position liquid pressure is supplied to the seal faces under all conditions of operation. They also 

ensure adequate circulation of the liquid at the seal faces to minimize the deposit of foreign 

matter on the seal parts. 

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Pump Troubleshooting Section 

Some of the operating problems you may encounter with centrifugal pumps as an Operator, 

together with the probable causes, are discussed in the following paragraphs. 

If a centrifugal pump DOES NOT DELIVER ANY LIQUID, the trouble may be caused by (1) 

insufficient priming; (2) insufficient speed of the pump; (3) excessive discharge pressure, such 

as might be caused by a partially closed valve or some other obstruction in the discharge line; 

(4) excessive suction lift; (5) clogged impeller passages; (6) the wrong direction of rotation (this 

may occur after motor overhaul); (7) clogged suction screen (if used); (8) ruptured suction line; 

or (9) loss of suction pressure. 

If a centrifugal pump delivers some liquid but operates at INSUFFICIENT CAPACITY, the 

trouble may be caused by (1) air leakage into the suction line; (2) air leakage into the stuffing 

boxes in pumps operating at less than atmospheric pressure; (3) insufficient pump speed; (4) 

excessive suction lift; (5) insufficient liquid on the suction side; (6) clogged impeller passages; 

(7) excessive discharge pressure; or (8) mechanical defects, such as worn wearing rings, 

impellers, stuffing box packing, or sleeves. 

If a pump DOES NOT DEVELOP DESIGN DISCHARGE PRESSURE, the trouble may be 

caused by (1) insufficient pump speed; (2) air or gas in the liquid being pumped; (3) mechanical 

defects, such as worn wearing rings, impellers, stuffing box packing, or sleeves; or (4) reversed 

rotation of the impeller (3-phase electric motor-driven pumps). If a pump WORKS FOR A 

WHILE AND THEN FAILS TO DELIVER LIQUID, the trouble may be caused by (1) air leakage 

into the suction line; (2) air leakage in the stuffing boxes; (3) clogged water seal passages; (4) 

insufficient liquid on the suction side; or (5) excessive heat in the liquid being pumped. 

If a motor-driven centrifugal pump DRAWS TOO MUCH POWER, the trouble will probably be 

indicated by overheating of the motor. The basic causes may be (1) operation of the pump to 

excess capacity and insufficient discharge pressure; (2) too high viscosity or specific gravity of 

the liquid being pumped; or (3) misalignment, a bent shaft, excessively tight stuffing box 

packing, worn wearing rings, or other mechanical defects. 

VIBRATION of a centrifugal pump is often caused by (1) misalignment; (2) a bent shaft; (3) a 

clogged, eroded, or otherwise unbalanced impeller; or (4) lack of rigidity in the foundation. 

Insufficient suction pressure may also cause vibration, as well as noisy operation and fluctuating 

discharge pressure, particularly in pumps that handle hot or volatile liquids. If the pump fails to 

build up pressure when the discharge valve is opened and the pump comes up to normal 

operating speed, proceed as follows: 

1. Shut the pump discharge valve. 

2. Secure the pump. 

3. Open all valves in the pump suction line. 

4. Prime the pump (fill casing with the liquid being pumped) and be sure that all air is 

expelled through the air cocks on the pump casing. 

5. Restart the pump. If the pump is electrically driven, be sure the pump is rotating in the correct 

direction. 

6. Open the discharge valve to “load” the pump. If the discharge pressure is not normal when 

the pump is up to its proper speed, the suction line may be clogged, or an impeller may be 

broken. It is also possible that air is being drawn into the suction line or into the casing. If any of 

these conditions exist, stop the pump and continue troubleshooting according to the technical 

manual for that unit. 

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Maintenance of Centrifugal Pumps 

When properly installed, maintained and operated, centrifugal pumps are usually trouble-free. 

Some of the most common corrective maintenance actions that you may be required to perform 

are discussed in the following sections. 

Repacking - Lubrication of the pump packing is extremely important. 

The quickest way to wear out the packing is to forget to open the water 

piping to the seals or stuffing boxes. If the packing is allowed to dry 

out, it will score the shaft. When operating a centrifugal pump, be sure 

there is always a slight trickle of water coming out of the stuffing box or 

seal. How often the packing in a centrifugal pump should be renewed 

depends on several factors, such as the type of pump, condition of the 

shaft sleeve, and hours in use. 

To ensure the longest possible service from pump packing, make 

certain the shaft or sleeve is smooth when the packing is removed 

from a gland. Rapid wear of the packing will be caused by roughness 

of the shaft sleeve (or shaft where no sleeve is installed). If the shaft is 

rough, it should be sent to the machine shop for a finishing cut to 

smooth the surface. If it is very rough, or has deep ridges in it, it will 

have to be renewed. It is absolutely necessary to use the correct packing. When replacing 

packing, be sure the packing fits uniformly around the stuffing box. If you have to flatten the 

packing with a hammer to make it fit, YOU ARE NOT USING THE RIGHT SIZE. Pack the box 

loosely, and set up the packing gland lightly. Allow a liberal leak-off for stuffing boxes that 

operate above atmospheric pressure. 

Next, start the pump. Let it operate for about 30 minutes before you adjust the packing gland for 

the desired amount of leak-off. This gives the packing time to run-in and swell. You may then 

begin to adjust the packing gland. Tighten the adjusting nuts one flat at a time. Wait about 30 

minutes between adjustments. Be sure to tighten the same amount on both adjusting nuts. If 

you pull up the packing gland unevenly (or cocked), it will cause the packing to overheat and 

score the shaft sleeves. Once you have the desired leak-off, check it regularly to make certain 

that sufficient flow is maintained. 


Mechanical seals are rapidly replacing conventional packing as the 

means of controlling leakage on rotary and positive-displacement 

pumps. Mechanical seals eliminate the problem of excessive stuffing 

box leakage, which causes failure of pump and motor bearings and 

motor windings. Mechanical seals are ideal for pumps that operate 

in closed systems (such as fuel service and air-conditioning, chilledwater, 

and various cooling systems). They not only conserve the 

fluid being pumped, but also improve system operation. The type of 

material used for the seal faces will depend upon the service of the 

pump. Most water service pumps use a carbon material for one of 

the seal faces and ceramic (tungsten carbide) for the other. When 

the seals wear out, they are simply replaced. 

You should replace a mechanical seal whenever the seal is removed from the shaft for any 

reason, or whenever leakage causes undesirable effects on equipment or surrounding spaces. 

Do not touch a new seal on the sealing face because body acid and grease or dirt will cause the 

seal to pit prematurely and leak. 

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Mechanical shaft seals are positioned on the shaft by stub or step sleeves. Mechanical shaft 

seals must not be positioned by setscrews. Shaft sleeves are chamfered (beveled) on outboard 

ends for easy mechanical seal mounting. 

Mechanical shaft seals serve to ensure that liquid pressure is supplied to the seal faces under 

all conditions of operation. They also ensure adequate circulation of the liquid at the seal faces 

to minimize the deposit of foreign matter on the seal parts. 

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Troubleshooting Table for Well/Pump Problems 

1. Well pump will not start. 

2. Well pump will not shut off. 

3. Well pump starts and stops too frequently (excessive cycle rate). 

4. Sand sediment is present in the water. 

5. Well pump operates with reduced flow. 

6. Well house flooded without recent precipitation. 

7. Red or black water complaints. 

8. Raw water appears turbid or a light tan color following rainfall. 

9. Coliform tests are positive. 


1A. Circuit breaker or overload relay tripped. 

1B. Fuse(s) burned out. 

1C. No power to switch box. 

1D. Short, broken or loose wire. 

1E. Low voltage. 

1F. Defective motor. 

1G. Defective pressure switch. 

2A. Defective pressure switch. 

2B. Cut-off pressure setting too high. 

2C. Float switch or pressure transducer not 

functioning. 

3A. Pressure switch settings too close. 

3B. Pump foot valve leaking. 

3C. Water-logged hydropneumatic tank. 

4A. Problems with well screen or gravel envelope. 

5A. Valve on discharge partially closed or line clogged. 

5B. Well is over-pumped. 

5C. Well screen clogged. 

6A. Check valve not operating properly. 

6B. Leakage occurring in discharge piping or valves. 

7A. Water contains excessive iron (red brown) and/or manganese (black water). 

7B. Complainant’s hot water needs maintenance. 

8A. Surface water entering or influencing well. 

9A. Sample is invalid. 

9B. Sanitary protection of well has been breached. 


1A. Reset breaker or manual overload relay. 

1B. Check for cause and correct, replace fuse(s). 

1C. Check incoming power supply. Contact power company. 

1D. Check for shorts and correct, tighten terminals, replace broken wires. 

1E. Check incoming line voltage. Contact power company if low. 

1F. Contact electrical contractor. 

1G. Check voltage of incoming electric supply with pressure switch closed. Contact power 

company if voltage low. Perform maintenance on switch if voltage normal. 

2A. Check switch for proper operation. Replace switch. 

2B. Adjust setting. 

2C. Check and replace components or cable as needed. 

3A. Adjust settings. 

3B. Check for backflow. Contact well contractor. 

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3C. Check air volume. Add air if needed. If persistent, check air compressor, relief valve, air 

lines and connections, and repair if needed. 

4A. Contact well contractor. 

5A. Open valve, unclog discharge line. 

5B. Check static water level and compare to past readings. If significantly lower, notify well 

contractor. 

5C. Contact well contractor. 

6A. Repair or replace check valve. 

6B. Inspect and repair/replace as necessary. 

7A. Test for iron and manganese at well. If levels exceed 0.3 mg/L iron or 0.005mg/L 

manganese, contact regulatory agency, TA provider or water treatment contractor. 

7B. Check hot water heater and flush if needed. 

8A. Check well for openings that allow surface water to enter. Check area for sinkholes, 

fractures, or other physical evidence of surface water intrusion. Check water turbidity. Notify 

regulatory agency if >0.5 NTU. Check raw water for coliform bacteria. Notify regulatory agency 

immediately if positive. 

9A. Check sampling technique, sampling container, and sampling location and tap. 

9B. Notify regulatory agency immediately and re-sample for re-testing. 

This brush is used to dislodge debris inside well casing. Just a big toilet cleaning brush. 

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SCADA 

What is SCADA? 

SCADA stands for Supervisory Control and Data Acquisition. As the name indicates, it is not 

a full control system, but rather focuses on the supervisory level. As such, it is a purely 

software package that is positioned on top of hardware to which it is interfaced, in general via 

Programmable Logic Controllers (PLCs), or other commercial hardware modules. 

Contemporary SCADA systems exhibit predominantly open-loop control characteristics and 

utilize predominantly long distance communications, although some elements of closed-loop 

control and/or short distance communications may also be present. Systems similar to 

SCADA systems are routinely seen in treatment plants and distribution systems. These are 

often referred to as Distributed Control Systems (DCS). They have similar functions to 

SCADA systems, but the field data gathering or control units are usually located within a 

more confined area. Communications may be via a local area network (LAN), and will 

normally be reliable and high speed. A DCS system usually employs significant amounts of 

closed loop control. 

What is Data Acquisition? 

Data acquisition refers to the method used to access and control information or data from the 

equipment being controlled and monitored. The data accessed are then forwarded onto a 

telemetry system ready for transfer to the different sites. They can be analog and digital 

information gathered by sensors, such as flowmeter, ammeter, etc. It can also be data to 

control equipment such as actuators, relays, valves, motors, etc. 

So Why or Where Would You Use SCADA? 

SCADA can be used to monitor and control plant or equipment. The control may be 

automatic, or initiated by operator commands. The data acquisition is accomplished firstly by 

the RTU's (remote Terminal Units) scanning the field inputs connected to the RTU (RTU may 

also be called a PLC - programmable logic controller). This is usually at a fast rate. The 

central host will scan the RTU's (usually at a slower rate.) 

The data is processed to detect alarm conditions, and if an alarm is present, it will be 

displayed on special alarm lists. Data can be of three main types. Analogue data (i.e. real 

numbers) will be trended (i.e. placed in graphs). 

Digital data (on/off) may have alarms attached to 

one state or the other. Pulse data (e.g. counting 

revolutions of a meter) is normally accumulated or 

counted. 

The primary interface to the operator is a graphical 

display (mimic) usually via a PC Screen which shows 

a representation of the plant or equipment in 

graphical form. Live data is shown as graphical 

shapes (foreground) over a static background. As 

the data changes in the field, the foreground is 

updated. A valve may be shown as open or closed. Analog data can be shown either as a 

number, or graphically. The system may have many such displays, and the operator can 

select from the relevant ones at any time. 

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Finger is shown pointing to a Lantern Ring. This old school method of sealing a 

pump is still out there. Notice the packing on both sides of the ring. The packing 

joints need to be staggered and the purpose of this device is to allow air to the 

Stuffing Box. 

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Backflow Cross-Connection Section 

A Certified Backflow Tester examining a Double Check Detector check fire line 

assembly. 

Notice the water meter which will 

detect any un-authorized water 

usage that will be used in the fire 

line. 

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Recent Backflow Situations 

Oregon 1993 

Water from a drainage pond, used for lawn irrigation, is pumped into the potable water 

supply of a housing development. 

California 1994 

A defective backflow device in the water system of the County Courthouse apparently 

caused a sodium nitrate contamination that sent 19 people to the hospital. 

New York 1994 

An 8-inch reduced pressure principle backflow assembly in the basement of a hospital 

discharged under backpressure conditions, dumping 100,000 gallons of water into the 

basement. 

Nebraska 1994 

While working on a chiller unit of an air conditioning system at a nursing home, a hole in the 

coil apparently allowed Freon to enter the circulating water and from there into the city water 

system. 


The blue tinted water in a pond at an amusement park backflowed into the city water system 

and caused colored water to flow from homeowners’ faucets. 


A film company shooting a commercial for television accidentally introduced a chemical into 

the potable water system. 

Iowa 1994 

A backflow of water from the Capitol Building chilled water system contaminated potable 

water with Freon. 

Indiana 1994 

A water main break caused a drop in water pressure allowing anti- freeze from an air 

conditioning unit to backsiphon into the potable water supply. 

Washington 1994 

An Ethylene Glycol cooling system was illegally connected to the domestic water supply at a 

veterinarian hospital. 

Ohio 1994 

An ice machine connected to a sewer sickened dozens of people attending a convention. 

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Cross-Connection Terms 

Cross-Connection 

A cross-connection is any temporary or permanent connection between a public water 

system or consumer’s potable (i.e., drinking) water system and any source or system 

containing nonpotable water or other substances. An example is the piping between a public 

water system or consumer’s potable water system and an auxiliary water system, cooling 

system, or irrigation system. 

Contaminant: Any natural or man-made physical, chemical, biological, or radiological 

substance or matter in water, which is at a level that may have an adverse effect on public 

health, and which is known or anticipated to occur in public water systems. 

Contamination: To make something bad; to pollute or infect something. To reduce the 

quality of the potable (drinking) water and create an actual hazard to the water supply by 

poisoning or through spread of diseases. 

Corrosion: The removal of metal from copper, other metal surfaces and concrete surfaces in 

a destructive manner. Corrosion is caused by improperly balanced water or excessive water 

velocity through piping or heat exchangers. 

Cross-Connection Failure: Could be the source of an organic substance causing taste and 

odor problems in a water distribution system. 

Cross-Connection: A physical connection between a public water system and any source of 

water or other substance that may lead to contamination of the water provided by the public 

water system through backflow. The mixing of two unlike qualities of water; for example, the 

mixing of good water with a polluting substance like a chemical. 

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Common Cross-Connections 

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Backflow 

Backflow is the undesirable reversal of flow of nonpotable water or other substances through 

a cross-connection and into the piping of a public water system or consumer’s potable water 

system. There are two types of backflow--backpressure and backsiphonage. 

Backsiphonage 

Backpressure 

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Backsiphonage 

Backsiphonage is backflow caused by a negative pressure (i.e., a vacuum or partial vacuum) 

in a public water system or consumer’s potable water system. The effect is similar to drinking 

water through a straw. 

Backsiphonage can occur when there is a stoppage of water supply due to nearby 

firefighting, a break in a water main, etc. 

Cooling Tower - A common location 

for finding a cross-connection. 

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Backpressure 

Backpressure backflow is backflow caused by a downstream pressure that is greater than 

the upstream or supply pressure in a public water system or consumer’s potable water 

system. Backpressure (i.e., downstream pressure that is greater than the potable water 

supply pressure) can result from an increase in downstream pressure, a reduction in the 

potable water supply 

pressure, or a 

combination of both. 

Increases in downstream 

pressure can be created 

by pumps, temperature 

increases in boilers, etc. 

Reductions in potable 

water supply pressure 

occur whenever the 

amount of water being 

used exceeds the 

amount of water being 

supplied, such as during 

water line flushing, 

firefighting, or breaks in 

water mains. 

Backpressure 

Example: 

Booster Pumps, 

Pressure Vessels, 

Boilers 

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Backflow and Cross-Connection Review Statements 

Backflow Condition: A continuous positive pressure in a distribution system is essential for 

preventing what event? 

Backflow or Cross-Connection Failure: What might be the source of an organic substance 

causing taste and odor problems in a water distribution system? 

Backflow Prevention: To stop or prevent the occurrence of, the unnatural act of reversing 

the normal direction of the flow of liquids, gases, or solid substances back in to the public 

potable (drinking) water supply. See Cross-connection control. 

Backflow: Minimum water pressure must be maintained to ensure adequate customer 

service during peak flow periods. However, minimum positive pressure must be maintained 

in mains to protect against backflow or backsiphonage from cross-connections. 

Backflow: Name the most common CAUSE for public water supply contamination. Backflow 

or cross-connection. 

Backflow: To reverse the natural and normal directional flow of liquids, gases, or solid 

substances back in to the public potable (drinking) water supply. This is normally an 

undesirable effect. 

Backflow: What does a backsiphonage condition usually cause? Reduced pressure or 

negative pressure on the service or supply side. 

Backflow: What does a double check valve backflow assembly provide effective protection 

from? Both backpressure and backsiphonage of pollution only. 

Backflow: What is equipment that utilizes water for cooling, lubrication, washing or as a 

solvent always susceptible to? A cross-connection. 

Backflow: What is the definition of ‘backflow’? A reverse flow condition that causes water or 

mixtures of water and other liquids, gases, or substances to flow back into the distribution 

system. 

Backflow: What is the difference between a reduced pressure principle backflow device and 

a double check backflow device? The RP has a relief valve. 

Backflow: What is the maximum time period between having a backflow device tested by a 

certified backflow tester? 1 year. 

Backflow: What must an operator ensure when installing a pressure vacuum breaker 

backflow device? It must be at least 12 inches above the highest downstream outlet. 

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Backflow Responsibility 

The Public Water Purveyor 

The primary responsibility of the water purveyor is to develop and maintain a program to 

prevent or control contamination from water sources of lesser quality or other contamination 

sources from entering into the public water system. Under the provisions of the Safe Drinking 

Water Act of 1974, (SDWA) and current Groundwater Protection rules the Federal 

Government, through the EPA (Environmental Protection Agency), set national standards of 

safe drinking water. The separate states are responsible for the enforcement of these 

standards as well as the supervision of public water systems and the sources of drinking 

water. The water purveyor or supplier is held responsible for compliance to the provisions of 

the Safe Drinking Water Act, to provide a warranty that water quality by their operation is in 

conformance with EPA standards at the source, and is delivered to the customer without the 

quality being compromised as it is delivered through the distribution system. 

This is specified in the Code of Federal Regulations (Volume 40, Paragraph141.2 

Section c )”: 

Maximum contaminant level means the permissible level of a contaminant in water which is 

delivered to the free flowing outlet of the ultimate user of a public water system, except in the 

case of turbidity where the maximum permissible level is measured at the point of entry 

(POE) to the distribution system. Contaminants added to the water under circumstances 

controlled by the user, except those resulting from corrosion of piping and plumbing caused 

by water quality, are excluded from this definition. 

The Water Consumer 

Has the responsibility to prevent contaminants from entering into the public water system by 

way of their individual plumbing system, and retain the expenses of installation, 

maintenance, and testing of the approved backflow prevention assemblies installed on their 

individual water service line. 

The Certified General Backflow Tester 

Has the responsibility to test, maintain, inspect, repair, and report/notify on approved 

backflow prevention assemblies as authorized by the persons that have jurisdiction over 

those assemblies. 

Backflow into a public water system can pollute or contaminate the water in that system (i.e., 

backflow into a public water system can make the water in that system unusable or unsafe to 

drink), and each water supplier has a responsibility to provide water that is usable and safe 

to drink under all fore-seeable circumstances. Furthermore, consumers generally have 

absolute faith that water delivered to them through a public water system is always safe to 

drink. For these reasons, each water supplier must take reasonable precautions to protect its 

public water system against backflow. 

What should water suppliers do to control cross-connections and protect their public 

water systems against backflow? 

Water suppliers usually do not have the authority or capability to repeatedly inspect every 

consumer’s premises for cross-connections and backflow protection. Alternatively, each 

water supplier should ensure that a proper backflow preventer is installed and maintained at 

the water service connection to each system or premises that pose a significant hazard to 

the public water system. 

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Generally, this would include the water service connection to each dedicated fire protection 

system or irrigation piping system and the water service connection to each of the following 

types of premises: 

(1) Premises with an auxiliary or reclaimed water system. 

(2) Industrial, medical, laboratory, marine or other facilities where objectionable substances 

are handled in a way that could cause pollution or contamination of the public water system. 

(3) Premises exempt from the State Plumbing Code and premises where an internal 

backflow preventer required under the State Plumbing Code is not properly installed or 

maintained. 

(4) Classified or restricted facilities; and 

(5) Tall buildings. 

Each water supplier should also ensure that a proper backflow preventer is 

installed and maintained at each water loading station owned or operated by 

the water supplier. 

Degrees of Hazards (HAZARD RATINGS) High, Contaminant and Low, Pollutional 

Containment Protection, Secondary protection 

This approach utilizes a minimum of backflow devices and isolates the customer from the 

water main. It virtually insulates the customer from potentially contaminating or polluting the 

public water supply system. Containment protection does not protect the customer within his 

own building, it does effectively remove him from the possibility public water supply 

contamination. Containment protection is usually a backflow prevention device as close as 

possible to the customer’s water meter and is often referred to as “Secondary Protection”. 

This type of backflow protection is excellent for water purveyors and is the least expense to 

the water customer, but does not protect the occupants of the building. 

Internal Protection, Primary protection 

The water purveyor may elect to protect his customers on a domestic internal protective 

basis and/or “fixture outlet protective basis,” in this case cross-connection-control devices 

(backflow preventors) are placed at internal hazard locations and at all locations where 

cross-connections may exist, including the “last free flowing outlet.” This type of 

protection entails extensive cross-connection survey work usually performed by a plumbing 

inspector or a Cross-Connection Specialist. In a large water supply system, internal 

protection in itself is virtually impossible to achieve and police due to the quantity of systems 

involved, the complexity of the plumbing systems inherent in many industrial sites, and the 

fact that many plumbing changes are made within commercial establishments that do not get 

the plumbing department’s approval or require that the water department inspects when the 

work is completed. 

Internal protection is the most expensive and best type of backflow protection for both the 

water purveyor and the customer alike, but is very difficult to maintain. In order for the 

purveyor to provide maximum protection of the water distribution system, consideration 

should be given to requiring the owner of the premises to provide at his own expense, 

adequate proof that his internal water supply system complies with the local or state 

plumbing code(s). 

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Backflow Prevention Methods and Assemblies 

Approved Air Gap Separation (AG) 

An approved air gap is a physical separation between the free flowing discharge end of a 

potable water supply pipeline, and the overflow rim of an open or non-pressure receiving 

vessel. These separations must be vertically orientated a distance of at least twice the inside 

diameter of the inlet pipe, but never less than one inch. 

An obstruction around or near an air gap may restrict the flow of air into the outlet pipe and 

nullify the effectiveness of the air gap to prevent backsiphonage. When the air flow is 

restricted, such as in the case of an air gap located near a wall, the air gap separation must 

be increased. Also, within a building where the air pressure is artificially increased above 

atmospheric, such as a sports stadium with a flexible roof kept in place by air blowers, the air 

gap separation must be increased. 

Air gap or vacuum breaker: What should a potable water line be equipped with when 

connected to a chemical feeder for fluoride? 

Air Gap Separation: A physical separation space that is present between the discharge 

vessel and the receiving vessel, for an example, a kitchen faucet. 

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Atmospheric Vacuum Breaker (AVB) 

The Atmospheric Vacuum Breaker contains a float check (poppet), a check seat, and an air 

inlet port. The device allows air to enter the water line when the line pressure is reduced to a 

gauge pressure of zero or below. The air inlet valve is not internally loaded. To prevent the 

air inlet from sticking closed, the device must not be installed on the pressure side of a 

shutoff valve, or wherever it may be under constant pressure more than 12 hours during a 24 

hour period. Atmospheric vacuum breakers are designed only to prevent backflow caused by 

backsiphonage from low health hazards. 

Atmospheric Vacuum Breaker Uses: Irrigation systems, commercial dishwasher and laundry 

equipment, chemical tanks and laboratory sinks (backsiphonage only, non-pressurized 

connections). (Note: hazard relates to the water purveyor's risk assessment; plumbing codes 

may allow AVB for high hazard fixture isolation). 

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Pressure Vacuum Breaker Assembly (PVB) 

The Pressure Vacuum Breaker Assembly consists of a spring-loaded check valve, an 

independently operating air inlet valve, two resilient seated shutoff valves, and two properly 

located resilient seated test cocks. It shall be installed as a unit as shipped by the 

manufacturer. The air inlet valve is internally loaded to the open position, normally by means 

of a spring, allowing installation of the assembly on the pressure side of a shutoff valve. 

Double Check Valve Assembly (DC) 

The Double Check Valve Assembly consists of two internally loaded check valves, either 

spring loaded or internally weighted, two resilient seated full ported shutoff valves, and four 

properly located resilient seated test cocks. This assembly shall be installed as a unit as 

shipped by the manufacturer. The double check valve assembly is designed to prevent 

backflow caused by backpressure and backsiphonage from low health hazards. 

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Reduced Pressure Backflow Assembly (RP) 

The reduced pressure backflow assembly consists of two independently acting spring loaded 

check valves separated by a spring loaded differential pressure relief valve, two resilient 

seated full ported shutoff valves, and four properly located resilient seated test cocks. This 

assembly shall be installed as a unit shipped by the manufacturer. 

During normal operation, the pressure between the two check valves, referred to as the zone 

of reduced pressure, is maintained at a lower pressure than the supply pressure. If either 

check valve leaks, the differential pressure relief valve maintains a differential pressure of at 

least two (2) psi between the supply pressure, and the zone between the two check valves, 

by discharging water to atmosphere. The reduced pressure backflow assembly is designed 

to prevent backflow caused by backpressure and backsiphonage from low to high health 

hazards. 

Various examples of RPs and these are easy to find around most water treatment 

facilities. Incredibly, these devices can be found installed incorrectly, or even installed 

backwards with the guts removed. 

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Why do Backflow Preventers Have to be Tested Periodically? 

Mechanical backflow preventers have internal seals, springs, and moving parts that are 

subject to fouling, wear, or fatigue. Also, mechanical backflow preventers and air gaps can 

be bypassed. Therefore, all backflow preventers have to be tested periodically to ensure that 

they are functioning properly. A visual check of air gaps is sufficient, but mechanical backflow 

preventers have to be tested with properly calibrated gauge equipment. 

Backflow prevention devices must be tested annually to ensure that they work properly. It is 

usually the responsibility of the property owner to have this test done and to make sure that a 

copy of the test report is sent to the Public Works Department or Water Purveyor. 

If a device is not tested annually, Public Works or the Water Purveyor will normally notify the 

property owner, asking them to comply. If the property owner does not voluntarily test their 

device, the Water provider may be forced to turn off water service to that property. State law 

may require the Water provider to discontinue water service until testing is complete. 

Troubleshooting Table for Cross Connection Problem 

1. Sudsy or soapy water. 

3. Positive Coliform. 

3. Coloring in the water (unusual colors such as bright blue). 

4. Organic odors. 


1A. Hose connected to an unprotected hose bib with the other end in a bucket or sink of 

soapy water. 

2A. Hose connected to an unprotected hose bib with the other end lying on the floor of the 

pump house, on the ground in the car wash area, in the wading or swimming pool or other 

nonpotable liquid. 

2B. Unprotected potable water line feeding a lawn irrigation system. 

2C. Submerged inlet, e.g. faucet submerged. 

3A. Backflow from toilet. 

4A. Handheld pesticide/herbicide applicator attached to unprotected hose. 


1A. Equip all hose bibs with an AVB. 

2A. Equip all hose bibs with an AVB. 

2B. Install a backflow preventer on the 

potable water line feeding the irrigation 

system. 

2C. Relocate faucet above flood level. 

3A. Get help. Bring in someone who 

understands cross connections to 

evaluate the system. 

4A. Don't use these devices 

This PVB is not 12 inches above the ground nor the highest downstream outlet. 

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Water Distribution Section 

Competent Person Duties and Responsibilities 

� Performs daily inspections of the protective equipment, trench conditions, safety 

equipment and adjacent areas. 

� Inspections shall be made prior to the start of work and as needed throughout the 

shift. 

� Inspections shall be made after every rainstorm or other hazard occurrence. 

� Knowledge of emergency contact methods, telephone or radio dispatch. 

� Removes employees and all other personnel from hazardous conditions and makes 

all changes necessary to ensure their safety. 

� Insures all employees have proper protective equipment, hard-hats, reflective vests, 

steel-toed boots, harnesses, eye protection, hearing protection and drinking water. 

� Categorize soil conditions and conduct visual and manual tests. 

� Determine the appropriate protection system to be used. 

� Maintain on-site records of inspections and protective systems used. 

� Maintain on site a Hazard Communication program, Material Safety Data Sheets and 

a Risk Management Plan if necessary. 

� Maintain current First Aid and CPR certifications. Maintain current Confined Space 

certification training. 

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Water Distribution Valves 

Water distribution valves are provided in the design of the water systems to allow for the 

isolation and shut-off of water when emergency conditions occur. It is important to recognize 

that these valves are a critical link in the management of emergencies that occur in the 

distribution system. Additionally, these valves are usually operated infrequently therefore, 

the establishment of an annual valve exercising program is essential to the viability of an 

utility emergency operations plan. 

Emergency operations of water valves presumes that the system operators are familiar with 

the exact locations of many key water valves within the water system. Equal in importance is 

the knowledge that when these valves need to be operated in order to isolate a section of the 

distribution system, they will operate and close effectively in order to prevent a large loss of 

the water recourse and excessive property damage. 

Routine valve inspections should be conducted on the water system valves and the following 

tasks are accomplished: 

� The accuracy of all valves and valve boxes is verified against existing records. If 

inconsistencies are found, the records are updated to reflect accurate information. 

� An inspection is performed on each valve stem and nut to determine if any damage 

exists. 

� The valve is fully closed and the number of turns necessary to accomplish a full 

closing is recorded. 

� The valve is re-opened, and the system flows are re-established. 

� The valve box and cover is cleaned, inspected for damaged and painted blue. 

Exercising of all valves should be accomplished at the same time as the valve inspection. 

The exercising program assures that the valve operates and loosens any encrustation from 

valve seats and gates. Many valve manufacturers recommend that the valve stem be 

completely opened and then backed off by one complete turn. 

Portable valve exercising machine. 

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Distribution System Design 

System design depends on the area where you live. You may be a flatlander, like in Texas, 

and the services could be spread out for miles. You may live in the Rocky Mountain area 

and have many fluctuating elevations. Some areas may only serve residents on a part time 

basis and water will sit for long periods of time, while other areas may have a combination of 

peaks and valleys with short and long distances of service. Before you design the system, 

you need to ask yourself some basic questions. 

1. What is the source of water? 

2. What is the population? 

3. What kind of storage will I need for high demand and emergencies? 

4. How will the pressure be maintained? 

System Elements 

The elements of a water distribution system include: distribution mains, arterial mains, 

storage reservoirs, and system accessories. These elements and accessories are described 

as follows: 

Distribution Mains Distribution mains are the pipelines that make up the distribution 

system. Their function is to carry water from the water source or treatment works to users. 

Arterial Mains Arterial mains are distribution mains of large size. They are interconnected 

with smaller distribution mains to form a complete gridiron system. 

Storage Reservoirs Storage reservoirs are structures used to store water. They also 

equalize the supply or pressure in the distribution system. A common example of a storage 

reservoir is an aboveground water storage tank. 

Inside a giant booster pump station. 

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System Accessories Include the Following 

Booster stations are used to increase water pressure from storage tanks for low-pressure 

mains. 

Valves control the flow of water in the distribution system by isolating areas for repair or by 

regulating system flow or pressure. 

Different types of Gate Valves. (Linear) 

Top photograph is valve ready for a valve re-placement. It has a Mechanical Type Joint. 

Bottom photograph is OS&Y commonly found on fire lines. This is a Flange type joint. 

(Outside Screw and Yoke) As the gate is lifted or opened, the stem will rise. 

Gate valves should be used in the distribution system for main line isolation only. Gate Valve 

is a linear type of valve. Gate valves should be stored upright with the gate down. 

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Distribution Valves 

The purpose of installing shutoff valves in water mains at various locations within the 

distribution system is to allow sections of the system to be taken out of service for repairs or 

maintenance, without significantly curtailing service over large areas. 

Valves should be installed at intervals not greater than 5,000 feet in long supply lines, and 

1,500 feet in main distribution loops or feeders. All branch mains connecting to feeder mains 

or feeder loops should have valves installed as close to the feeders as practical. In this way, 

branch mains can be taken out of service without interrupting the supply to other locations. 

In the areas of greatest water demand, or when the dependability of the distribution system 

is particularly important, valve spacing of 500 feet may be appropriate. 

At intersections of distribution mains, the number of valves required is normally one less 

than the number of radiating mains. The valve omitted from the line is usually the one that 

principally supplies flow to the intersection. Shutoff valves should be installed in 

standardized locations (that is, the northeast comer of intersections or a certain distance 

from the center line of streets), so they can be easily found in emergencies. All buried small- 

and medium-sized valves should be installed in valve boxes. For large shutoff valves (about 

30 inches in diameter and larger), it may be necessary to surround the valve operator or 

entire valve within a vault or manhole to allow repair or replacement. 

Gate Valves 

Gate valves are used when a straight-line flow of fluid and minimum flow restriction are 

needed. Gate valves are so-named because the part that either stops or allows flow through 

the valve acts somewhat like a gate. 

The gate is usually wedge-shaped. When the valve is wide open, the gate is fully drawn up 

into the valve bonnet. This leaves an opening for flow through the valve the same size as the 

pipe in which the valve is installed. Therefore, there is little pressure drop or flow restriction 

through the valve. Gate valves are not suitable for throttling purposes. The control of flow is 

difficult because of the valve’s design, and the flow of fluid slapping against a partially open 

gate can cause extensive damage to the valve. Except as specifically authorized, gate 

valves should not be used for throttling. 

Ball Valves 

Most ball valves are the quick-acting type. They require only a 90-degree turn to either 

completely open or close the valve. However, many are operated by planetary gears. This 

type of gearing allows the use of a relatively small handwheel and operating force to operate 

a fairly large valve. The gearing does, however, increase the operating time for the valve. 

Some ball valves also contain a swing check located within the ball to give the valve a check 

valve feature. Ball valves should be either fully-on or fully-off. 

Valve Exercising 

Valve exercising should be done once per year (especially main line valves) to detect 

malfunctioning valves and to prevent valves from becoming inoperable due to freezing or 

build-up of rust or corrosion. A valve inspection should include drawing valve location maps 

to show distances (ties) to the valves from specific reference points (telephone poles, 

stonelines, etc.). 

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Hydrants are designed to allow water from the distribution 

system to be used for fire-fighting purposes. 

Bottom of a dry barrel fire hydrant; there is a drainage hole 

on the back of this hydrant, sometimes referred to as a 

“weep hole”. 

Notice the corrosion inside this cast iron main. 

This corrosion is caused by chemical changes produced by electricity or electrolysis. 

We call this type of corrosion tuberculation. It is a protective crust of corrosion 

products that have built up over a pit caused by the loss of metal due to corrosion or 

electrolysis. This type of corrosion will decrease the C-Factor and the carrying 

capacity in a pipe. Crenothrix bacteria or Red-Iron bacteria will live in the bioslime in 

this type of tuberculation. 

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Common Rotary Valves 

Globe Valve Rotary Valve 

Primarily used for flow regulation, and works similar to a faucet. They are rare to find in 

most distribution systems, but can be found at treatment plants. Always follow standard 

safety procedures when working on a valve. Most Globes have compact OS & Y type, 

bolted bonnet, rising stems with renewable seat rings. The disc results with most 

advanced design features provide the ultimate in dependable, economical flow control. 

Globe valves should usually be installed with the inlet below the valve seat. For severe 

throttling service, the valve may be installed so that the flow enters over the top of the seat 

and goes down through it. Note that in this arrangement, the packings will be constantly 

pressurized. If the valve is to be installed near throttling service, verify with an outside 

contractor or a skilled valve technician. Globe valves, per se, are not suitable for throttling 

service. 

The valve should be welded onto the line with the disc in the fully closed position. Leaving 

it even partially open can cause distortion and leaking. Allow time for the weld to cool 

before operating the valve the first time in the pipeline. The preferred orientation of a 

globe valve is upright. The valve may be installed in other orientations, but any deviation 

from vertical is a compromise. Installation upside down is not recommended because it 

can cause dirt to accumulate in the bonnet. 

Globe Valve Problems and Solutions 

If the valve stem is improperly lubricated or damaged--Disassemble the valve and 

inspect the stem. Acceptable deviation from theoretical centerline created by joining 

center points of the ends of the stem is 0.005"/ft of stem. Inspect the threads for any 

visible signs of damage. 

359 

Valve System Design Course © 1/13/2006 (866) 557-1746 www.ABCTLC.com

Small grooves less than 0.005" can be polished with an Emory cloth. Contact specialized 

services or an outside contractor if run-out is unacceptable or large grooves are 

discovered on the surface of the stem. 

If the valve packing compression is too tight--Verify the packing bolt torque and adjust 

if necessary. 

Foreign debris is trapped on threads and/or in the packing area.--This is a common 

problem when valves are installed outdoors in sandy areas and the areas not cleaned 

before operating. 

Always inspect threads and packing area for particle obstructions; even seemingly small 

amounts of sand trapped on the drive can completely stop large valves from cycling. The 

valve may stop abruptly when a cycle is attempted. With the line pressure removed from 

the valve, disconnect the actuator, gear operator or handwheel and inspect the drive nut, 

stem, bearings and yoke bushing. Contaminated parts should be cleaned with a lint-free 

cloth using alcohol, varsol or equivalent. All parts should be re-lubricated before reassembled. 

If the valves are installed outdoors in a sandy area, it may be desirable to 

cover the valves with jackets. 

If the valve components are faulty or damaged--contact specialized services or an 

outside contractor. 

If the valve’s handwheel is too small--Increasing the size of the handwheel will reduce 

the amount of torque required to operate the valve. If a larger handwheel is installed, the 

person operating the valve must be careful not to over-torque the valve when closing it. 

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Bellow Seal Valve 

Always follow standard safety procedures when working on a valve. 

Bellows seal valves provide a complete hermetic seal of the working fluid. They are used 

in applications where zero leakage of the working fluid into the environment is permitted. 

Bellows seal valves are specially modified versions of the standard valves. The installation 

information that applies to gate and globe valves will apply to bellows seal valves. 

A packing leak signifies that the bellows has ruptured or the bellows-assembly weld has a 

crack. Professor Rusty does not recommend repairing or reusing a damaged bellows. 

Instead, Professor Rusty suggests replacing the entire bonnet assembly including bellows 

and stem. 

Bellow’s style Globe valve on left, Gate valve on right. 

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Pressure Sustaining Valve 

Pressure sustaining valves are used to sustain the system pressure to a predetermined 

maximum level. The applications balance the pressure distribution throughout the whole 

system by maintaining the minimum pressure for high altitude users. Pressure sustaining 

valves are also used to prevent discharging of the pipe system when any user starts to 

operate. More in a few more pages. 

Pressure Reducing Valve 

Pressure reducing valves maintain a predetermined outlet pressure which remains steady 

and unaffected by either changing of inlet pressure and/or various demands. Pressure 

Reducing Valves are self-contained control valves which do not require external power. 

More in a few more pages. 

Insertion Valves Rotary Valve 

Sometimes you have to obtain a shut down and you have only two choices. Do it hot or 

cut in an insertion or inserting valve. An Insertion valve is normally a Gate Valve that is 

made to be installed on a hot water main. A few years ago, this was a serious feat. First, 

you had to pour ten yards of mud or cement and come back and cut the valve in. No 

longer. The Insertion valve machine and tap works like a tapping sleeve. The only 

difference is that the tap points up and not to the side. I recommend that any major 

system budget money to purchase this equipment. It will pay for itself on the first job. 

Otherwise, contract the work out. You can see in the photograph a manually operated 

tapping machine. I prefer the electric. Note: see the sweet shoring shield set-up. It is 

rare to see a nice shoring job. 

Hydro Stop valve insertion machine 

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Needle Valves Rotary Valve 

A needle valve, as shown on the right, is used to make relatively fine adjustments in the 

amount of fluid flow. The distinguishing characteristic of a needle valve is the long, 

tapered, needle- like point on the end of the valve stem. This "needle" acts as a disk. The 

longer part of the needle is smaller than the orifice in the valve seat and passes 

through the orifice before the needle seats. This arrangement permits a very gradual 

increase or decrease in the size of the opening. Needle valves are often used as 

component parts of other, more complicated valves. For example, they are used in 

some types of reducing valves. 

Plug Valves Rotary Valve 

Plug valves are extremely versatile valves that are 

found widely in low-pressure sanitary and industrial 

applications, especially petroleum pipelines, 

chemical processing and related fields, and power 

plants. They are high capacity valves that can be 

used for directional flow control, even in moderate 

vacuum systems. They can safely and efficiently 

handle gas and liquid fuel, and extreme 

temperature flow, such as boiler feed water, 

condensate, and similar elements. They can also 

be used to regulate the flow of liquids containing 

suspended solids (slurries). 

Cut-away of a Plug Valve. 

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Ball or Corporation Stop Rotary Valve Small Valves 2 inches and smaller 

Most commonly found on customer or water meters. All small backflow assemblies will 

have two Ball valves. It is the valve that is either fully on or fully off; and the one that you 

use to test the abilities of a water service rookie. The best trick is to remove the ball from 

the Ball valve and have a rookie Jump a Stop. The Corp is usually found at the water 

main on a saddle. Some people say that the purpose of the Corp is to regulate the 

service. I don’t like that explanation. No one likes to dig up the street to regulate the 

service and Ball valves are only to be used fully on or fully off. 

Most ball valves are the quick-acting type. They require only a 90-degree turn to either 

completely open or close the valve. However, many are operated by planetary gears. This 

type of gearing allows the use of a relatively small handwheel and operating force to 

operate a fairly large valve. Always follow standard safety procedures when working on a 

valve. 

The gearing does, however, increase the 

operating time for the valve. Some ball 

valves also contain a swing check located 

within the ball to give the valve a check 

valve feature. The brass ball valve is often 

used for house appliance and industry 

appliance, the size range is 1/4”-4”. Brass 

or zinc is common for body, brass or iron 

for stem, brass or iron for ball, aluminum, 

stainless steel, or iron for handle including 

a Teflon seal in the ball housing. Flush the 

pipeline before installing the valve. Debris 

allowed to remain in the pipeline (such as weld spatters, welding rods, bricks, tools, etc.) 

can damage the valve. After installation, cycle the valve a minimum of three times and retorque 

bolts as required. Ensure that the valve is in the open position and the inside of the 

body bore of the valve body/body end is coated with a suitable spatter guard. 

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Bird’s eye view of the coveted stainless steel ball. 

Removing the ball is very difficult. I think they use a robot to tighten the rear nut to 

keep you from removing it. I recommend that you always use pipe dope or Teflon 

tape when installing a Stop. I know a lot of you think that brass or bronze will 

make up the slack, but pipe dope, or Teflon dope or tape makes a nicer job and 

makes for an easier removal. 

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Butterfly Valve Rotary Valve 

Usually a huge water valve found in both treatment plants and throughout the distribution 

system. If the valve is not broken, it is relatively easy to operate. It is usually 

accompanied with a Gate valve used as a by-pass to prevent water hammer. When I was 

a Valve man, it seemed that every Bypass valve was broken closed when near a Butterfly 

valve. 

These are rotary type of valves usually found on large transmission lines. They may also 

have an additional valve beside it known as a “bypass valve” to prevent a water hammer. 

Some of these valves can require 300-600 turns to open or close. Most Valvemen (or the 

politically correct term “Valve Operators”) will use a 

machine to open or close a Butterfly Valve. The 

machine will count the turns required to open or 

close the valve. 

Butterfly valves should be installed with the valve 

shaft horizontal or inclined from vertical. Always 

follow standard safety procedures when working on 

a valve. 

The valve should be mounted in the preferred 

direction, with the "HP" marking. Thermal insulation 

of the valve body is recommended for operating 

temperatures above 392°F (200°C). The valve should be installed in the closed position 

to ensure that the laminated seal in the disc is not damaged during installation. 

If the pipe is lined, make sure that the valve disc does not contact the pipe lining during 

the opening stroke. Contact with lining can damage the valve disc. 

54 inch Butterfly valve on a huge transmission line. Nice job but no shoring, no 

ladder or valve blocking. 

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Butterfly Valve Problems 

A butterfly valve may have jerky operation for the following reasons: 

If the packing is too tight--Loosen the packing torque until it is only hand tight. Tighten to 

the required level and then cycle the valve. Re-tighten, if required. CAUTION: Always follow 

safety instructions when operating on valve. 

If the shaft seals are dirty or worn out--Clean or replace components, as per assemblydisassembly 

procedure. CAUTION: Always follow safety instructions when operating on a 

valve. 

If the shaft is bent or warped--The shaft must be replaced. 

Remove valve from service and contact an outside contractor or 

your expert fix-it person. 

If the valve has a pneumatic actuator, the air supply may be 

inadequate--Increase the air supply pressure to standard operating 

level. Any combination of the following may prevent the valve shaft 

from rotating: 

If the actuator is not working--Replace or repair the actuator as 

required. Please contact specialized services or an outside 

contractor for assistance. 

If the valve is packed with debris--Cycle the valve and then flush 

to remove debris. A full cleaning may be required if flushing the valve does not improve valve 

shaft rotation. Flush or clean valve to remove the debris. 

A broken 54 inch Butterfly and a worker inside the water main preparing the interior 

surface. Notice, this is a Permit Required Confined Space. Hot work permit is also 

required. Side note, there is a plastic version of the 54 and 60 inch Butterfly valve. 

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Actuators and Control Devices 

Directional control valves route the fluid to the desired actuator. They usually consist of a 

spool inside a cast iron or steel housing. The spool slides to different positions in the 

housing, and intersecting grooves and channels route the fluid based on the spool's position. 

The spool has a central (neutral) position maintained with springs; in this position the supply 

fluid is blocked, or returned to tank. Sliding the spool to one side routes the hydraulic fluid to 

an actuator and provides a return path from the actuator to the tank. When the spool is 

moved to the opposite direction the supply and return paths are switched. When the spool is 

allowed to return to the neutral (center) position the actuator fluid paths are blocked, locking 

it in position. 

Directional control valves are usually designed to be stackable, with one valve for each 

hydraulic cylinder, and one fluid input supplying all the valves in the stack. 

Tolerances are very tight in order to handle the high pressure and avoid leaking, spools 

typically have a clearance with the housing of less than a thousandth of an inch. The valve 

block will be mounted to the machine's frame with a three point pattern to avoid distorting the 

valve block and jamming the valve's sensitive components. 

The spool position may be actuated by mechanical levers, hydraulic pilot pressure, or 

solenoids which push the spool left or right. A seal allows part of the spool to protrude 

outside the housing, where it is accessible to the actuator. 

The main valve block is usually a stack of off the shelf directional control valves chosen by 

flow capacity and performance. Some valves are designed to be proportional (flow rate 

proportional to valve position), while others may be simply on-off. The control valve is one of 

the most expensive and sensitive parts of a hydraulic circuit. 

Pressure reducing valves reduce the supply pressure as needed for various circuits. 

Pressure relief valves are used in several places in hydraulic machinery: on the return circuit 

to maintain a small amount of pressure for brakes, pilot lines, etc; on hydraulic cylinders, to 

prevent overloading and hydraulic line/seal rupture; on the hydraulic reservoir, to maintain a 

small positive pressure which excludes moisture and contamination. 

Sequence valves control the sequence of hydraulic circuits; to insure that one hydraulic 

cylinder is fully extended before another starts its stroke, for example. Shuttle valves provide 

a logical function. 

Check valves are one way valves, allowing an accumulator to charge and maintain its 

pressure after the machine is turned off, for example. Pilot controlled Check valves are one 

way valves that can be opened (for both directions) by a foreign pressure signal. For 

instance, if the load should not be held by the check valve anymore. Often the foreign 

pressure comes from the other pipe that is connected to the motor or cylinder. 

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Counterbalance valves. A counterbalance valve is, in fact, a special type of pilot controlled 

check valve. Whereas the check valve is open or closed, the counterbalance valve acts a bit 

like a pilot controlled flow control. 

Cartridge valves are in fact the inner part of a check valve; they are off the shelf components 

with a standardized envelope, making them easy to populate a proprietary valve block. They 

are available in many configurations: on/off, proportional, pressure relief, etc. They generally 

screw into a valve block and are electrically controlled to provide logic and automated 

functions. 

Hydraulic fuses are in-line safety devices designed to automatically seal off a hydraulic line if 

pressure becomes too low, or safely vent fluid if pressure becomes too high. 

Auxiliary valves. Complex hydraulic systems will usually have auxiliary valve blocks to 

handle various duties unseen to the operator, such as accumulator charging, cooling fan 

operation, air conditioning power, etc... They are usually custom valves designed for a 

particular machine, and may consist of a metal block drilled with ports and channels. 

Cartridge valves are threaded into the ports and may be electrically controlled by switches or 

a microprocessor to route fluid power as needed. 

We can see both valve actuators control devices and Butterfly valves as well. 

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Pressure Reducing Valves Rotary Valve 

Pressure Relief Valve 

Pressure relief valves are used to release excess pressure that may develop as a result of a 

sudden change in the velocity of the water flowing in the pipe. 

PRVs assist in a variety of functions, from keeping system pressures safely below a desired 

upper limit to maintaining a set pressure in part of a circuit. Types include relief, reducing, 

sequence, counterbalance, and unloading. All of these are normally closed valves, except for 

reducing valves, which are normally open. For most of these valves, a restriction is 

necessary to produce the required pressure control. One exception is the externally piloted 

unloading valve, which depends on an external signal for its actuation. 

The most practical components for maintaining secondary, lower pressure in a hydraulic 

system are pressure-reducing valves. Pressure-reducing valves are normally open, 2-way 

valves that close when subjected to sufficient downstream pressure. There are two types: 

direct acting and pilot operated. 

Direct acting - A pressure-reducing valve limits the maximum pressure available in the 

secondary circuit regardless of pressure changes in the main circuit, as long as the work load 

generates no back flow into the reducing valve port, in which case the valve will close. 

The pressure-sensing signal comes from the downstream side (secondary circuit). This 

valve, in effect, operates in reverse fashion from a relief valve (which senses pressure from 

the inlet and is normally closed). As pressure rises in the secondary circuit, hydraulic force 

acts on area A of the valve, closing it partly. Spring force opposes the hydraulic force, so that 

only enough oil flows past the valve to supply the secondary circuit at the desired pressure. 

The spring setting is adjustable. 

When outlet pressure reaches that of the valve setting, the valve closes except for a small 

quantity of oil that bleeds from the low-pressure side of the valve, usually through an orifice 

in the spool, through the spring chamber, to the reservoir. Should the valve close fully, 

leakage past the spool could cause pressure build-up in the secondary circuit. To avoid this, 

a bleed passage to the reservoir keeps it slightly open, preventing a rise in downstream 

pressure above the valve setting. The drain passage returns leakage flow to reservoir. 

(Valves with built-in relieving capability also are available to eliminate the need for this 

orifice.) 

Constant and Fixed Pressure Reduction 

Constant-pressure-reducing valves supply a preset pressure, regardless of main circuit 

pressure, as long as pressure in the main circuit is higher than that in the secondary. These 

valves balance secondary-circuit pressure against the force exerted by an adjustable spring 

which tries to open the valve. When pressure in the secondary circuit drops, spring force 

opens the valve enough to increase pressure and keep a constant reduced pressure in the 

secondary circuit. Fixed pressure reducing valves supply a fixed amount of pressure 

reduction regardless of the pressure in the main circuit. For instance, assume a valve is set 

to provide reduction of 250 psi. If main system pressure is 2,750 psi, reduced pressure will 

be 2,500 psi; if main pressure is 2,000 psi, reduced pressure will be 1,750 psi. 

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This valve operates by balancing the force exerted by the pressure in the main circuit against 

the sum of the forces exerted by secondary circuit pressure and the spring. Because the 

pressurized areas on both sides of the poppet are equal, the fixed reduction is that exerted 

by the spring. 

How do Pressure Relief Valves Operate? 

Most pressure relief valves consist of a main valve and pilot control system. The basic main 

Cla-Val valve is called a Hytrol Valve. 

When no pressure is in the valve, the spring and the weight of the diaphragm assembly holds 

the valve closed. 

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Often a small box can be connected to an existing pilot PRV valve to control the main 

Pressure Reducing Valve on the pipe network. This single box contains both the control 

electronics and an integral data logger to save the cost and space of having both a controller 

and a separate data logger. There are basically two types of PRV controllers, either timebased 

(to reduce the pipe pressure at low demand times, e.g. at night) or flow modulated 

controllers which can realize leakage savings throughout the day and night (by adjusting the 

pressure according to the demand to prevent excessive pressure at any time of the day or 

night). 

Municipal water distribution systems often have widely varying flow rates ranging 

from 7:00 am peak demand (or even fire-flow) to minimal 2:00am demand. One valve 

size cannot accurately control the wide range of flows. A low flow bypass pressure 

reducing valve is often used to control pressure at the low flow conditions. Both 

valves are open at maximum flow demand. The small valve is set at a slightly higher 

pressure than the larger valve. 

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Service Connections 

Service connections are used to connect individual buildings or other plumbing systems to 

the distribution system mains. 

Water Meter Re-setter, riser or sometimes referred to as a copper yoke. 

Common distribution repair fittings. Single check valve, Poly Pig, 1-inch repair 

clamp, 4-inch full circle clamp, T- Bolt and a corp. and saddle. 

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System Layouts 

There are three general ways systems are laid out 

to deliver water (photograph your quarter section 

layouts). They include: 

A. Tree systems 

B. Loop or Grid systems 

C. Dead-end systems: Undesirable, taste and 

odor problems. 

Tree System 

Older water systems frequently were expanded 

without planning and developed into a treelike 

system. This consists of a single main that 

decreases in size as it leaves the source and 

progresses through the area originally served. Smaller pipelines branch off the main and 

divide again, much like the trunk and branches of a tree. 

A treelike system is not desirable because the size of the old main limits the expansion of 

the system needed to meet increasing demands. In addition, there are many dead ends in 

the system where water remains for long periods, causing undesirable tastes and odors in 

nearby service lines. The most reliable means to provide water for firefighting is by 

designing redundancy into the system. There are several advantages gained by laying out 

water mains in a loop or grid, with feeder and distributor mains interconnecting at roadway 

intersections and other regular intervals. 

Friction Loss 

Water will still be distributed through the system if a single section fails. The damaged 

section can be isolated and the remainder of the system will still carry water. Water supplied 

to fire hydrants will feed from multiple directions. Thus, during periods of peak fire flow 

demand, there will be less impact from "friction loss" in water mains as the velocity within 

any given section of main will be less since several mains will be sharing the supply. 

The system shall be designed to maintain a minimum positive pressure of 25 psi. in all parts 

of the system at all times, 35 psi. is desirable.. Water pipe shall conform to applicable 

specifications and standards for the type of pipe to be used. The following shall govern the 

separation of water lines from possible sources of pollution: 

1. Whenever possible, a water line shall be laid at least 10 feet horizontally from 

any existing or proposed sewer line. 

2. Whenever water lines must cross sewers, the water line shall be laid at such 

an elevation that the bottom of the water line is 18 inches above the top of the 

sewer. This vertical separation shall be maintained for that portion of the water 

line located within 10 feet horizontally of any sewer or drain it crosses, said 10 

feet to be measured as the normal distance from the water line to the drain or 

sewer. The sewer shall be constructed of cast iron pipe, type K copper, or 

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Drain, Waste and Vent (DWV) plastic pipe (Schedule 40) with water-tight 

joints for a distance of 10 feet from each side of the water line. All crossings 

shall be made at right angles. 

3. Where conditions prevent the minimum horizontal and/or vertical separation 

specified above, special consultation shall be obtained from the Department to 

determine other routes of water piping. 

4. No water line shall pass through, or come into contact with, any part of a 

sewer manhole. 

5. There shall be no physical connection between a community water system 

and a non-community or private water system, unless the non-community or 

private water system conforms to community water system requirements. 

6. Lines for potable water shall be laid at least 25 feet horizontally from any 

underground sewage seepage field. 

Plumbing Fixture Backflow Protection 

The water supply lines shall have no physical 

connection with nonpotable water supplies. All 

plumbing shall be in accord with the Uniform 

Plumbing Code available from this Department. All 

plumbing fixtures and other equipment connected 

to the water system shall be so constructed and 

installed so as to safeguard the water system from 

the possibility of contamination through crossconnections 

or backsiphonage. Laundry units and 

equipment shall be so constructed and installed so 

as to prevent the contamination of the contents by 

the backflow of sewage. 

Water main breaks are common and this problem 

is the primary reason to keep a free chlorine 

residual of at least 2 mg/l in the distribution 

system, another reason is backflow. 

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Disinfection of Repaired Pipeline Sections 

You should recognize that the protection of the public health of its water customers is the 

primary role of a water provider. Accordingly, the disinfection of all repaired water 

appurtenances is paramount to the return of the water system to its normal operation mode. 

Prior to initiating the disinfection process, a thorough cleaning of all repaired pipes and or 

reservoirs must be accomplished. The following table indicates the amount of Sodium 

Hypochlorite and Calcium Hypochlorite that is necessary to disinfect 100,000 gallons of 

water. 

Disinfection Table 

For 100,000 Gallons Of Water 

Desired Pounds of Gallons 

Chlorine Liquid of Sodium 

Dose in Chlorine Hypo Pounds of 

MG/L Required Chlorite 10% 15% Calcium 

Required Available Available Hypo 

5% Chlorine Chlorine Chlorite 

Available Required. 65% 

Chlorine Available 

2 1.7 3.9 2.0 1.3 2.6 

10 8.3 19.4 9.9 12.8 12.8 

50 42 97 49.6 64 64 

Spare Parts Inventory 

You should maintain a complete inventory of spare parts for the maintenance and repair of 

all water transmission and distribution lines. The water lines in the system range in size 

between ¾ inch and 16 inches in diameter. Additionally, you should maintain spare motor 

controls, pump ends, and motors for all wells and booster stations. Water system personnel 

can repair the entire range of water lines without assistance from outside contractors. 

Stand-by warehouse personnel should be available twenty four hours per day to assist in 

the delivery of spare parts in instances requiring emergency repair. 

Preventative maintenance can extend the life of any water pipeline. Pipes can deteriorate 

on the inside as a result of corrosion and on the outside as a result of aggressive soil and 

moisture. The Water Department should maintain an intense leak detection program to 

effectively reduce operating costs and provide revenue savings by reducing lost and 

unaccounted for water. Leaks can originate in joints and fittings or any corroded portion of a 

pipeline. 

Additionally, leaks will undermine the pavement and water soak the area around the leaking 

section of pipeline. When leaks are discovered, they should be repaired within twenty-four 

hours after properly locating all underground utilities through the Underground Service Alert 

or “Blue Stake” procedure. 

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Distribution Key Words 

Solidification/Stabilization: Solidification/stabilization (S/S) techniques are akin to locking 

the contaminants in the soil. It is a process that physically encapsulates the contaminant. 

This technique can be used alone or combined with other treatment and disposal methods. 

The most common form of S/S is a cement process. It simply involves the addition of cement 

or a cement-based mixture, which thereby limits the solubility or mobility of the waste 

constituents. These techniques are accomplished either in-situ, by injecting a cement based 

agent into the contaminated materials or ex situ, by excavating the materials, machinemixing 

them with a cement-based agent, and depositing the solidified mass in a designated 

area. The goal of the S/S process is to limit the spread, via leaching of contaminated 

material. The end product resulting from the solidification process is a monolithic block of 

waste with high structural integrity. Types of solidifying/stabilizing agents include the 

following: Portland; gypsum; modified sulfur cement, consisting of elemental sulfur and 

hydrocarbon polymers; and grout, consisting of cement and other dry materials, such as 

acceptable fly ash or blast furnace slag. Processes utilizing modified sulfur cement are 

typically performed ex situ. 

Semi-volatile organic compounds: Semi-volatile organic compounds (SVOCs) are 

compounds with higher vapor pressures than VOCs and therefore are released as gas much 

more slowly from materials. They are as likely to be transferred to humans by contact or by 

attaching to dust and being ingested. 

Whereas VOCs tend to be emitted rapidly in the first few hours or days after installation of a 

product then taper off over time, SVOCs will be released by products more slowly and over a 

longer period of time. 

Toxicity Characteristic Leaching: Toxicity characteristic leaching procedure (TCLP) is a 

soil sample extraction method for chemical analysis. An analytical method to simulate 

leaching through a landfill. The leachate is analyzed for appropriate substances. 

TCLP comprises four fundamental procedures: 

� Sample preparation for leaching 

� Sample leaching 

� Preparation of leachate for analysis 

� Leachate analysis 

The TCLP procedure is generally useful for classifying waste material for disposal options. 

Extremely contaminated material is expensive to dispose. Grading is required to ensure safe 

disposal and to avoid paying for disposal of 'clean fill'. The main problem is that the TCLP 

test is based on the assumption that the waste material will be buried in landfill along with 

organic material. Organic matter is not really buried with other waste anymore (composting 

usually applies) and other leachate techniques may be more appropriate. The pH of the 

sample material is first established, and then leached with an acetic acid / sodium hydroxide 

solution at a 1:20 mix of sample to solvent. The leachate solution is sealed in extraction 

vessel for general analytes, or possibly pressure sealed as in zero-headspace extractions 

(ZHE) for volatile organic compounds and tumbled for 18 hours to simulate an extended 

leaching time in the ground. 

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Types of Pipes Used in the Distribution Field 

Several types of pipe are used in water distribution systems, but only the most common types 

used by operators will be discussed. These piping materials include copper, plastic, 

galvanized steel, and cast iron. Some of the main characteristics of pipes made from these 

materials are presented below. 

Plastic Pipe (PVC) 

Plastic pipe has seen extensive use in current construction. Available in different lengths and 

sizes, it is lighter than steel or copper and requires no special tools to install. Plastic pipe has 

several advantages over metal pipe. It is flexible, it has superior resistance to rupture from 

freezing, it has complete resistance to corrosion and, in addition, it can be installed above 

ground or below ground. 

One of the most versatile plastic and polyvinyl resin pipes is the polyvinyl chloride (PVC). 

PVC pipes are made of tough, strong thermoplastic material that has an excellent 

combination of physical and chemical properties. Its chemical resistance and design strength 

make it an excellent material for application in various mechanical systems. 

Sometimes polyvinyl chloride is further chlorinated to obtain a stiffer design, a higher level of 

impact resistance, and a greater resistance to extremes of temperature. A CPVC pipe (a 

chlorinated blend of PVC) can be used not only in cold-water systems, but also in hot-water 

systems with temperatures up to 210°F. Economy and ease of installation make plastic pipe 

popular for use in either water distribution and supply systems or sewer drainage systems. 

Various types and sizes of coupons or tap cut-outs. You will want to date and collect 

these cut-outs to determine the condition of the pipe or measure the corrosion. 

Plastic Pipe (PVC) 

This is currently the most common type of pipe used in distribution systems. It is available in 

diameters of 1/2" and larger, and in lengths of 10', 20', and 40'. A main advantage is its light 

weight, allowing for easy installation. A disadvantage is its inability to withstand shock loads. 

Since it is non-metallic, a tracer wire must be installed with the PVC water main so that it can 

be located after burial. 

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The National Sanitation Foundation (NSF) currently lists most brands of PVC pipe as being 

acceptable for potable water use. This information should be stamped on the outside of the 

pipe, along with working pressure and temperature, diameter and pipe manufacturer. PVC 

pipe will have the highest C Factor of all the above pipes. The higher the C factor, the 

smoother the pipe. 

Cast Iron (CIP) 

This is another type of piping material that has been in use for a long time. It is found in 

diameters from 3" to 48". Advantages of this material are its long life, durability and ability to 

withstand working pressures up to 350 psi. Disadvantages include the fact that it is heavy, 

difficult to install and does not withstand shock loading. Although it is not currently the 

material of choice, there is still a lot of it in the ground. 

Ductile Iron Pipe (DIP) 

This was developed to overcome the breakage problems associated with cast iron pipe. It 

can be purchased in 4" to 45" diameters and lengths of 18' to 20'. Its main advantage is that 

it is nearly indestructible by internal or external pressures. It is manufactured by injecting 

magnesium into molten cast iron. It is sometimes protected from highly corrosive soils by 

wrapping the pipe in plastic sheeting prior to installation. This practice can greatly extend the 

life of this type of pipe. 

Steel Pipe 

This pipe is often used in water treatment plants and 

pump stations. It is available in various diameters and 

in 20' or 21' lengths. Its main advantage is the ability 

to form it into a variety of shapes. It also exhibits 

good yielding and shock resistance. It has a smooth 

interior surface and can withstand pressures up to 

250 psi. A disadvantage is that it is easily corroded 

by both soil and water. 

To reduce corrosion problems, steel pipe is usually 

galvanized or dipped in coal-tar enamel and wrapped 

with coal-tar impregnated felt. At present, however, 

coal-tar products are undergoing scrutiny from a 

health standpoint and it is recommended that the 

appropriate regulatory agencies be contacted prior to 

use of this material. 

Asbestos Cement Pipe (ACP) 

This pipe is manufactured from Portland cement, long 

fibrous asbestos and silica. It is available in 

diameters from 3" to 36" and in 13' lengths. Its main 

advantages are its ability to withstand corrosion and its excellent hydraulic flow 

characteristics due to its smoothness. A major disadvantage is that it is brittle and is easily 

broken during construction or by shock loading. There is some concern regarding the 

possible release of asbestos fibers in corrosive water and there has been much debate over 

the health effects of ingested asbestos. 

Of greater certainty, however, is the danger posed by inhalation of asbestos fibers. Asbestos 

is considered a hazardous material, and precautionary measures must be taken to protect 

water utility workers when cutting, tapping or otherwise handling this type of pipe. 

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Galvanized Pipe 

Galvanized pipe is commonly used for the water distributing pipes inside a building to supply 

hot and cold water to the fixtures. This type of pipe is manufactured in 21-ft lengths. It is 

Galvanized (coated with zinc) both inside and outside at 

the factory to resist corrosion. Pipe sizes are based on 

nominal INSIDE diameters. Inside diameters vary with the 

thickness of the pipe. Outside diameters remain constant 

so that pipe can be threaded for standard fittings. 

Copper 

Copper is one of the most widely used materials for tubing. 

This is because it does not rust and is highly resistant to 

any accumulation of scale particles in the pipe. This tubing 

is available in four different types: K, L, and M for water and DWV for sewer applications. 

K has the thickest walls, and M, the thinnest walls, with L’s thickness in between the other two. 

The thin walls of copper tubing are soldered to copper fittings. Soldering allows all the tubing and 

fittings to be set in place before the joints are finished. Generally, the result will be faster 

installation. 

Type K copper tubing is available as either rigid (hard temper) or flexible (soft temper) and is 

primarily used for underground service in the water distribution systems. 

Soft temper tubing is available in 40- or 60-ft coils, while hard temper tubing comes in 12- and 

20-ft straight lengths. Type L copper tubing is also available in either hard or soft temper and 

either in coils or in straight lengths. The soft temper tubing is often used as replacement 

plumbing because of the tube’s flexibility, which allows easier installation. 

Type L copper tubing is widely used in water distribution systems. 

Type M copper tubing is made in hard temper only and is available in straight lengths of 12 and 

20 ft. It has a thin wall and is used for branch 

supplies where water pressure is low, but it is NOT 

used for mains and risers. It is also used for chilled 

water systems, for exposed lines in hot-water 

heating systems, and for drainage piping. 

Notice that the pipe has been illegally cut with a 

power saw blade. Please check with OSHA on 

details on handling this common water pipe. ACP 

will not corrode like metal pipe but will become 

slow and stained by iron over time. It is easily 

cracked by heavy loads, but easily repaired with a 

clamp. 

ACP Pipe with illegal power saw cut marks. 

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Joints and Fittings 

Fittings vary according to the type of piping material used. The major types commonly 

used in water service include elbows, tees, unions, couplings, caps, plugs, nipples, 

reducers, and adapters. 

Besides bell-and-spigot joints, cast-iron water pipes and fittings are made with either 

flanged, mechanical, or screwed joints. The screwed joints are used only on smalldiameter 

pipe. 

Tapping Sleeve 

A Gate Valve is used to isolate sections of water mains. Not to be used to 

throttle or regulate the flow. A Globe valve should be used to regulate the flow. 

Be sure to chlorinate or disinfect all distribution parts such as valves and piping! 

Caps 

A pipe cap is a fitting with a female (inside) thread. It is used like a plug, except that the 

pipe cap screws on the male thread of a pipe or nipple. 

Couplings 

The three common types of couplings are straight coupling, reducer, and eccentric 

reducer. The STRAIGHT COUPLING is for joining two lengths of pipe in a straight run 

that do not require additional fittings. A run is that portion of a pipe or fitting continuing in 

a straight line in the direction of flow. 

A REDUCER is used to join two pipes of different 

sizes. The ECCENTRIC REDUCER (also called a 

BELL REDUCER) has two female (inside) threads 

of different sizes with centers so designed that when 

they are joined, the two pieces of pipe will not be in 

line with each other, but they can be installed to 

provide optimum drainage of the line. 

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Elbows (or ELLS) 90° and 45° 

These fittings (fig. 8-5, close to middle of figure) are used 

to change the direction of the pipe either 90 or 45 

degrees. REGULAR elbows have female threads at both 

outlets. STREET elbows change the direction of a pipe in 

a close space where it would be impossible or impractical 

to use an elbow and nipple. 

Both 45 and 90-degree street elbows are available with 

one female and one male threaded end. The REDUCING 

elbow is similar to the 90-degree elbow except that one 

opening is smaller than the other is. 

Nipples 

A nipple is a short length of pipe (12 in. or less) with a male thread on each end. It is 

used for extension from a fitting. At times, you may use the DIELECTRIC or 

INSULATING TYPE of fittings. These fittings connect underground tanks or hot-water 

tanks. They are also used with pipes of dissimilar metals. These help slow down 

corrosion that starts inside the pipe and works to the outside of the pipe. 

Do not heat or solder dielectric fittings. You may melt the plastic coating on them. 

Zinc is a coating on the outside and inside of pipes to slow corrosion. This process is 

called “Galvanization”. 

Tees 

A tee is used for connecting pipes of different diameters or for changing the direction of 

pipe runs. A common type of pipe tee is the STRAIGHT tee, which has a straightthrough 

portion and a 90-degree takeoff on one side. 

Notice the type of pipe connection device. 

This is known as a “Restraining Flange”. 

All three openings of the straight tee are of the same size. Another common type is the 

REDUCING tee, similar to the straight tee just described, except that one of the 

threaded openings is of a different size than the other. 

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Water Main Installation 

Installation of new or replacement pipe sections should be in accordance with good 

construction practices. The line must be buried a minimum of 30" below the ground 

surface to prevent freezing. The line must be bedded and backfilled properly, ensuring 

protection from weather and surface loadings. Also, thrust blocking (Kickers) at all 

bends, tees, and valves is essential to hold the pipe in place and prevent separation of 

line sections. Thrust blocking is not necessary 

if the pipe is welded. 

Disinfection of new installations or repaired 

sections is required prior to placing them in 

service. This can be accomplished by filling the 

line with a 25 mg/1 free chlorine solution and 

allowing it to stand for 24 hours. Valves and 

fittings used in the waterworks industry are 

made of cast iron, steel, brass, stainless and 

fiberglass. Enough gate valves should be 

placed throughout the system to enable 

problem areas (leaks, etc.) to be isolated and 

repaired with minimal service disruption. Air 

relief valves should be installed at highpoints in 

the system. Valves should be installed with 

valve boxes and covers. 

Regardless of the type of pipe installed, certain 

maintenance routines should be performed on 

the distribution system to maintain water quality and optimal service. These programs 

should be scheduled and performed on a regular basis. 

Flushing at blowoffs on dead end lines and at fire hydrants throughout the system should 

be done at least twice per year. Flushing is needed to remove stagnant water in dead 

ends and to remove accumulated sediment that results from turbidity, iron, manganese, 

etc. 

This should also help minimize customer complaints of water quality. Flushing should 

always be done from the source to the ends of the system. Affected customers should 

be notified of this process in advance. To do an adequate job of flushing, the flow 

should reach a velocity of at least 2.5 feet per second, known as the “minimum 

cleansing velocity” of the system (at hydrant locations). 

These tests are important to determine the adequacy of the distribution system in 

transmitting water, particularly during days of peak demand. Also, these tests can help 

determine if pipe capacity is decreasing over time due to internal corrosion or deposits. 

Pressure tests should be done at various locations in the distribution system several 

times per year. This helps to monitor the performance of the system and alert the 

operator to problems such as leaks or internal deposits. It is sometimes advantageous to 

have certain points in the system continuously monitored to provide a constant 

evaluation of the system. 

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Troubleshooting Table for Distribution System 

Problem 

1. Dirty water complaints 

2. Red water complaints 

3. No or low water pressure 

4. Excessive water usage. 


1A. Localized accumulations of debris, solids/particulates in distribution mains. 

1B. Cross connection between water system and another system carrying non-potable 

water. 

2A. Iron content of water from source is high. Iron precipitates in mains and 

accumulates. 

2B. Cast iron, ductile iron, or steel mains are corroding causing “rust” in the water. 

3A. Source of supply, storage or pumping station interrupted. 

3B. System cannot supply demands. 

3C. Service line, meter, or connections shutoff, or clogged with debris. 

3D. Broken or leaking distribution pipes. 

3E. Valve in system closed or broken. 

4A. More connections have been added to the system. 

4B. Excessive leakage (>15% of production)is occurring, meters are not installed or not 

registering properly. 

4C. Illegal connections have been made. 


1A. Collect and preserve samples for analysis if needed. Isolate affected part of main 

and flush. 

1B. Collect and preserve samples for analysis if needed. Conduct survey of system for 

cross connections. Contact State Drinking Water Agency. 

2A. Collect and test water samples from water source and location of complaints for iron. 

If high at both sites, contact regulatory agency, TA provider, consulting engineer or water 

conditioning company for assistance with iron removal treatment. 

2B. Collect and analyze samples for iron and corrosion parameters. Contact State 

Drinking Water Agency , TA provider, consulting engineer or water conditioning 

company for assistance with corrosion control treatment. 

3A. Check source, storage and pumping stations. Correct or repair as needed. 

3B. Check to see if demands are unusually high. If so, try to reduce demand. Contact 

State Drinking Water Agency, TA provider or consulting engineer. 

3C. Investigate and open or unclog service. 

3D. Locate and repair break or leak. 

3E. Check and open closed isolation and pressure-reducing valves. Repair or contact 

contractor if valves are broken. 

4A. Compare increase in usage over time with new connections added over same 

period. If correlation evident take action to curtail demand or increase capacity if needed. 

Contact State Drinking Water Agency , TA provider or consulting engineer. 

4B. Conduct a water audit to determine the cause. If leakage, contact regulatory agency, 

and consulting engineer or leak detection contractor. 

4C. Conduct survey to identify connections. 

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Filter assessment of filter media loss. 

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Glossary 

ABANDONED WELL: Wells that have been or need to be sealed by an approved method. 

ABSENCE OF OXYGEN: The complete absence of oxygen in water described as Anaerobic. 

ACCURACY: How closely an instrument measures the true or actual value. 

ACID AND BASE ARE MIXED: When an acid and a base are mixed, an explosive reaction occurs and 

decomposition products are created under certain conditions. 

ACID: Slowly add the acid to water while stirring. An operator should not mix acid and water or acid to a 

strong base. 

ACID RAIN: A result of airborne pollutants. 

ACTIVATED CHARCOAL (GAC or PAC): Granular Activated Charcoal or Powered Activated 

Charcoal. Used for taste and odor removal. A treatment technique that is not included in the grading of 

a water facility. 

ACTIVATED CARBON FILTRATION: Can remove organic chemicals that produce off-taste and odor. 

These compounds are not dangerous to health but can make the water unpleasant to drink. Carbon 

filtration comes in several forms, from small filters that attach to sink faucets to large tanks that contain 

removable cartridges. Activated carbon filters require regular maintenance or they can become a health 

hazard. 

ADSORPTION: Not to be confused with absorption. Adsorption is a process that occurs when a gas or 

liquid solute accumulates on the surface of a solid or a liquid (adsorbent), forming a film of molecules or 

atoms (the adsorbate). It is different from absorption, in which a substance diffuses into a liquid or solid 

to form a solution. The term sorption encompasses both processes, while desorption is the reverse 

process. Adsorption is present in many natural physical, biological, and chemical systems, and is widely 

used in industrial applications such as activated charcoal, synthetic resins, and water purification. 

ADSORPTION CLARIFIERS: The concept of the adsorption clarifier package plant was developed in 

the early 1980s. This technology uses an up-flow clarifier with low-density plastic bead media, usually 

held in place by a screen. This adsorption media is designed to enhance the sedimentation/clarification 

process by combining flocculation and sedimentation into one step. In this step, turbidity is reduced by 

adsorption of the coagulated and flocculated solids onto the adsorption media and onto the solids 

already adsorbed onto the media. Air scouring cleans adsorption clarifiers followed by water flushing. 

Cleaning of this type of clarifier is initiated more often than filter backwashing because the clarifier 

removes more solids. As with the tube-settler type of package plant, the sedimentation/ clarification 

process is followed by mixed-media filtration and disinfection to complete the water treatment. 

AIR GAP SEPARATION: A physical separation space that is present between the discharge vessel 

and the receiving vessel; for an example, a kitchen faucet. 

AIR HAMMER: A pneumatic cylindrical hammering device containing a piston used on air rotary rigs. 

The air hammer’s heavy piston moves up and down by the introduction of compressed air creating a 

hammering action on the bit. 

AIR HOOD: The most suitable protection when working with a chemical that produces dangerous 

fumes. 

AIR ENTRAINMENT: The dissolution or inclusion of air bubbles into water. 

AIRLIFT: The lifting of water and/or cuttings to the surface by the injection of high pressure bursts of 

air. Airlift occurs continuously when drilling with air rotary and can be used for well development with a 

surging technique. 

AIR PUMPING: Continuous airlifting to remove water from the well. 

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AIR ROTARY: A method of rotary well drilling that utilizes compressed air as the primary drilling fluid. 

AGGLOMERATION: A jumbled cluster or mass of varied parts. The act or process of agglomerating. 

ALKALINITY: Alkalinity or AT is a measure of the ability of a solution to neutralize acids to the 

equivalence point of carbonate or bicarbonate. Alkalinity is closely related to the acid neutralizing 

capacity (ANC) of a solution and ANC is often incorrectly used to refer to alkalinity. However, the acid 

neutralizing capacity refers to the combination of the solution and solids present (e.g., suspended 

matter, or aquifer solids), and the contribution of solids can dominate the ANC (see carbonate minerals 

below). 

ALTERNATIVE DISINFECTANTS: Disinfectants - other than chlorination (halogens) - used to treat 

water, e.g. ozone, ultraviolet radiation, chlorine dioxide, and chloramine. There is limited experience and 

scientific knowledge about the by-products and risks associated with the use of alternatives. 

ALGAE: Microscopic plants that are free-living and usually live in water. They occur as single cells 

floating in water, or as multicellular plants like seaweed or strands of algae that attach to rocks. 

ALPHA AND BETA RADIOACTIVITY: Represent two common forms of radioactive decay. Radioactive 

elements have atomic nuclei so heavy that the nucleus will break apart, or disintegrate spontaneously. 

When decay occurs, high-energy particles are released. These high-energy particles are called 

radioactivity. Although radioactivity from refined radioactive elements can be dangerous, it is rare to find 

dangerous levels of radioactivity in natural waters. An alpha particle is a doubly-charged helium nucleus 

comprised of two protons, two neutrons, and no electrons. A beta particle is a high-speed electron. 

Alpha particles do not penetrate matter easily, and are stopped by a piece of paper. Beta particles are 

much more penetrating and can pass through a millimeter of lead. 

ALUMINUM SULFATE: The chemical name for Alum. The molecular formula of Alum is 

Al2(SO4)3~14H2O. It is a cationic polymer. 

AMOEBA: Amoeba (sometimes amœba or ameba, plural amoebae) is a genus of protozoa that moves 

by means of pseudopods, and is well-known as a representative unicellular organism. The word 

amoeba or ameba is variously used to refer to it and its close relatives, now grouped as the 

Amoebozoa, or to all protozoa that move using pseudopods, otherwise termed amoeboids. 

AMMONIA: NH3 A chemical made with Nitrogen and Hydrogen and used with chlorine to disinfect 

water. Most ammonia in water is present as the ammonium ion rather than as ammonia. 

AMMONIATOR: A control device which meters gaseous ammonia directly into water under positive 

pressure. 

ANAEROBIC: An abnormal condition in which color and odor problems are most likely to occur. 

ANAEROBIC CONDITIONS: When anaerobic conditions exist in either the metalimnion or hypolimnion 

of a stratified lake or reservoir, water quality problems may make the water unappealing for domestic 

use without costly water treatment procedures. Most of these problems are associated with Reduction 

in the stratified waters. 

ANEROID: Using no fluid, as in aneroid barometer. 

ASEPTIC: Free from the living germs of disease, fermentation, or putrefaction. 

ANNULAR SPACE: The space between the borehole wall and either drill piping or casing within a well. 

ANNULUS: See Annular Space. 

AMMONIA: A chemical made with Nitrogen and Hydrogen and used with chlorine to disinfect water. 

AQUICLUDE: A layer or layers of soils or formations which water cannot pass through (ex - solid 

bedrock or very stiff clay). The opposite of aquifer. 

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AQUIFER: A saturated layer or layers of soils or formations which water can pass through and be 

provided in usable quantities to supply wells or springs (ex – saturated semi consolidated sediment or 

saturated fractured bedrock.) An underground geologic formation capable of storing significant amounts 

of water. 

AQUIFER PARAMETERS: Referring to such attributes as specific capacity, aquifer storage, 

transmissivity, hydraulic conductivity, gradient, and water levels. Refers to all of the components of 

Darcy’s Law and related parameters. 

ARTESIAN AQUIFER: A confined aquifer in which the pressure head results in a water elevation 

higher than the land surface. 

ARTESIAN WELL: A well constructed within an artesian aquifer. When an artesian well is opened it 

will flow naturally. 

As: The chemical symbol of Arsenic. 

AS NITROGEN: An expression that tells how the concentration of a chemical is expressed 

mathematically. The chemical formula for the nitrate ion is NO3 , with a mass of 62. The concentration 

of nitrate can be expressed either in terms of the nitrate ion or in terms of the principal element, 

nitrogen. The mass of the nitrogen atom is 14. The ratio of the nitrate ion mass to the nitrogen atom 

mass is 4.43. Thus a concentration of 10 mg/L nitrate expressed as nitrogen would be equivalent to a 

concentration of 44.3 mg/L nitrate expressed as nitrate ion. When dealing with nitrate numbers it is very 

important to know how numeric values are expressed. 

ASYNCHRONOUS: Not occurring at the same time. 

AUGER RIG: A drilling rig, which drives a rotating spiral flange to drill into the earth. 

ATOM: The general definition of an ion is an atom with a positive or negative charge. Electron is the 

name of a negatively charged atomic particle. 

BACKFLOW PREVENTION: To stop or prevent the occurrence of, the unnatural act of reversing the 

normal direction of the flow of liquid, gases, or solid substances back in to the public potable (drinking) 

water supply. See Cross-connection control. 

BACKFLOW: To reverse the natural and normal directional flow of a liquid, gases, or solid substances 

back in to the public potable (drinking) water supply. This is normally an undesirable effect. 

BACKSIPHONAGE: A liquid substance that is carried over a higher point. It is the method by which the 

liquid substance may be forced by excess pressure over or into a higher point. 

BACTERIA: Small, one-celled animals too small to be seen by the naked eye. Bacteria are found 

everywhere, including on and in the human body. Humans would be unable to live without the bacteria 

that inhabit the intestines and assist in digesting food. Only a small percentage of bacteria cause 

disease in normal, healthy humans. Other bacteria can cause infections if they get into a cut or wound. 

Bacteria are the principal concern in evaluating the microbiological quality of drinking water, because 

some of the bacteria-caused diseases that can be transmitted by drinking water are potentially lifethreatening. 

BACTERIOPHAGE: Any of a group of viruses that infect specific bacteria, usually causing their 

disintegration or dissolution. A bacteriophage (from 'bacteria' and Greek phagein, 'to eat') is any one of 

a number of viruses that infect bacteria. The term is commonly used in its shortened form, phage. 

Typically, bacteriophages consist of an outer protein hull enclosing genetic material. The genetic 

material can be ssRNA (single stranded RNA), dsRNA, ssDNA, or dsDNA between 5 and 500 kilo base 

pairs long with either circular or linear arrangement. Bacteriophages are much smaller than the bacteria 

they destroy - usually between 20 and 200 nm in size. 

BAILER: A device used to withdrawal water or sediment from a well utilizing a check valve type 

mechanism. 

BARITE: Processed barium sulfate, often used to increase drilling fluid densities in mud rotary. 

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BATTERY: A source of direct current (DC) may be used for standby lighting in a water treatment 

facility. The electrical current used in a DC system may come from a battery. 

BENTONITE: High quality clay composed primarily of montmorillonite. Used to thicken drilling mud in 

mud rotary drilling and used to form seals in well construction or abandonment. 

BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE (BAT): A level of technology 

based on the best existing control and treatment measures that are economically achievable within the 

given industrial category or subcategory. 

BEST MANAGEMENT PRACTICES (BMPs): Schedules of activities, prohibitions of practices, 

maintenance procedures, and other management practices to prevent or reduce the pollution of waters 

of the U.S. BMPs also include treatment requirements, operating procedures and practices to control 

plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage. 

BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE (BPT): A level of 

technology represented by the average of the best existing wastewater treatment performance levels 

within an industrial category or subcategory. 

BEST PROFESSIONAL JUDGMENT (BPJ): The method used by a permit writer to develop 

technology-based limitations on a case-by-case basis using all reasonably available and relevant data. 

BIT: The primary cutting edge of a drill string. 

BLANK CASING: A section of well casing that is solid. 

BLOWDOWN: The discharge of water with high concentrations of accumulated solids from boilers to 

prevent plugging of the boiler tubes and/or steam lines. In cooling towers, blowdown is discharged to 

reduce the concentration of dissolved salts in the recirculating cooling water. 

BOREHOLE DEVIATION: A boreholes’ orientation deviates from vertical while drilling. 

BOREHOLE GEOPHYSICS: A surveying technique of utilizing specialized tools to measure various 

physical parameters of the aquifer, formation, and well. 

BOREHOLE: The hole that is formed when drilling into the earth. 

BOULDER: An individual rock or solid mass of rock larger than 10 inches in diameter. 

BREAK POINT CHLORINATION: The process of chlorinating the water with significant quantities of 

chlorine to oxidize all contaminants and organic wastes and leave all remaining chlorine as free 

chlorine. 

BRIDGING: The tendency of sediment, filter, or seal media to create an obstruction if installed in too 

small an annulus or to rapidly. Also can occur within filter packs requiring development. 

BROMINE: Chemical disinfectant (HALOGEN) that kills bacteria and algae. This chemical disinfectant 

has been used only on a very limited scale for water treatment because of its handling difficulties. This 

chemical causes skin burns on contact, and a residual is difficult to obtain. 

BUCKET AUGER: A single cylindrical type of auger flight consisting of offset cutting blades at the 

bottom. A bucket auger rig rotates the bucket and its blades cut into the earth and fill the bucket with 

cuttings, which are dumped on the surface as needed. 

BUFFER: Chemical that resists pH change, e.g. sodium bicarbonate 

BUTTON BIT: A bit that is constructed with raised (typically carbide) buttons that strengthen the bit and 

aid in crushing and grinding efficiency. A button bit may be of a roller, hammer, or percussion type. 

CABLE TOOL: (Also called Percussion Drilling) A method of drilling which utilizes the consecutive 

lifting and dropping of a heavy drill string via a system of cables. 

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CALCIUM HARDNESS: A measure of the calcium salts dissolved in water. 

Ca: The chemical symbol for calcium. 

CADMIUM: A contaminant that is usually not found naturally in water or in very small amounts. 

CALCIUM HARDNESS: A measure of the calcium salts dissolved in water. 

CALCIUM ION: Is divalent because it has a valence of +2. 

CALCIUM, MAGNESIUM AND IRON: The three elements that cause hardness in water. 

CaOCl2.4H2O: The molecular formula of Calcium hypochlorite. 

CAPILLARY ACTION: The occurrence of an upward movement of fluid into previously unsaturated soil 

due to adhesion and surface tension which develops between the fluid and soil particles. 

CAPILLARY FRINGE: The uppermost portion of an aquifer where the vadose zone ends. The 

capillary action of soils permits moisture to extend upwards into the vadose zone within the capillary 

fringe. 

CARBON DIOXIDE GAS: The pH will decrease and alkalinity will change as measured by the Langelier 

index after pumping carbon dioxide gas into water. 

CARBONATE HARDNESS: Carbonate hardness is the measure of Calcium and Magnesium and other 

hard ions associated with carbonate (CO32 - ) and bicarbonate (HCO3 - ) ions contained in a solution, 

usually water. It is usually expressed either as parts per million (ppm or mg/L), or in degrees (KH - from 

the German "Karbonathärte"). One German degree of carbonate hardness is equivalent to about 

17.8575 mg/L. Both measurements (mg/L or KH) are usually expressed "as CaCO3" – meaning the 

amount of hardness expressed as if calcium carbonate was the sole source of hardness. Every 

bicarbonate ion only counts for half as much carbonate hardness as a carbonate ion does. If a solution 

contained 1 liter of water and 50 mg NaHCO3 (baking soda), it would have a carbonate hardness of 

about 18 mg/L as CaCO3. If you had a liter of water containing 50 mg of Na2CO3, it would have a 

carbonate hardness of about 29 mg/L as CaCO3. 

CARBONATE, BICARBONATE AND HYDROXIDE: Chemicals that are responsible for the alkalinity of 

water. 

CARBONATE ROCK: Rock that is composed primarily of calcium carbonate. 

CASING DRIVER: A percussion or hammering device used to force casing into the subsurface. 

CASING: A column of specially designed pipe of metal or plastic material installed in wells in order to 

keep a borehole open to permit serviceability of and/or construction and completion of a well within it. 

CATHEAD: A specially designed auxiliary reel that normally utilizes heavy rope rather than steel cable. 

Often used on cable tool or percussion drilling rigs for the operation of drive blocks. 

CATHODIC PROTECTION: An operator should protect against corrosion of the anode and/or the 

cathode by painting the copper cathode. Cathodic protection interrupts corrosion by supplying an 

electrical current to overcome the corrosion-producing mechanism. Guards against stray current 

corrosion. 

CAUSTIC: NaOH (also called Sodium Hydroxide) is a strong chemical used in the treatment process to 

neutralize acidity, increase alkalinity or raise the pH value. 

CAUSTIC SODA: Also known as sodium hydroxide and is used to raise pH. 

CAVERN: Large open spaces (>5ft.) encountered while drilling. More often associated with limestone 

formations in a karst environment. 

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CEILING AREA: The specific gravity of ammonia gas is 0.60. If released, this gas will accumulate first 

at the ceiling area. Cl2 gas will settle on the floor. 

CEMENT GROUT: Cement of fine consistency, capable of being pumped. Used to seal in and around 

wells. 

CENTRALIZER: Stand offs attached to well casing and screen to maintain annular space. In drilling, it 

has the same meaning as stabilizer or drill collar. 

CENTRIFUGAL FORCE: That force when a ball is whirled on a string that pulls the ball outward. On a 

centrifugal pump, it is that force which throws water from a spinning impeller. 

CENTRIFUGAL PUMP: A pump consisting of an impeller fixed on a rotating shaft and enclosed in a 

casing, having an inlet and a discharge connection. The rotating impeller creates pressure in the liquid 

by the velocity derived from centrifugal force. 

CESIUM (also Caesium): Symbol Cs- A soft, silvery-white ductile metal, liquid at room temperature, 

the most electropositive and alkaline of the elements, used in photoelectric cells and to catalyze 

hydrogenation of some organic compounds. 

CHAIN OF CUSTODY (COC): A record of each person involved in the possession of a sample from the 

person who collects the sample to the person who analyzes the sample in the laboratory. 

CHAIN OF CUSTODY (COC): A record of each person involved in the possession of a sample from the 

person who collects the sample to the person who analyzes the sample in the laboratory. 

CHECK VALVE: Allows water to flow in only one direction. 

CHELATION: A chemical process used to control scale formation in which a chelating agent "captures" 

scale-causing ions and holds them in solution. 

CHEMICAL FEED RATE: Chemicals are added to the water in order to improve the subsequent 

treatment processes. These may include pH adjusters and coagulants. Coagulants are chemicals, such 

as alum, that neutralize positive or negative charges on small particles, allowing them to stick together 

and form larger particles that are more easily removed by sedimentation (settling) or filtration. A variety 

of devices, such as baffles, static mixers, impellers and in-line sprays, can be used to mix the water and 

distribute the chemicals evenly. 

CHEMICAL OXIDIZER: KMnO4 or Potassium Permanganate is used for taste and odor control 

because it is a strong oxidizer which eliminates many organic compounds. 

CHEMICAL REATION RATE: In general, when the temperature decreases, the chemical reaction rate 

also decreases. The opposite is true for when the temperature increases. 

CHEMISORPTION: (or chemical adsorption) Is adsorption in which the forces involved are valence 

forces of the same kind as those operating in the formation of chemical compounds. 

CHLORAMINATION: Treating drinking water by applying chlorine before or after ammonia. This 

creates a persistent disinfectant residual called chloramines. 

CHLORAMINES: A group of chlorine ammonia compounds formed when chlorine combines with 

organic wastes in the water. Chloramines are not effective as disinfectants and are responsible for eye 

and skin irritation as well as strong chlorine odors. 

CHLORINATION: The process in water treatment of adding chlorine (gas or solid hypochlorite) for 

purposes of disinfection. 

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CHLORINE: A chemical used to disinfect water. Chlorine is extremely reactive, and when it comes in 

contact with microorganisms in water it kills them. Chlorine is added to swimming pools to keep the 

water safe for swimming. Chlorine is available as solid tablets for swimming pools. Some public water 

system’s drinking water treatment plants use chlorine in a gas form because of the large volumes 

required. Chlorine is very effective against algae, bacteria and viruses. Protozoa are resistant to 

chlorine because they have thick coats; protozoa are removed from drinking water by filtration. 

CHLORINE DEMAND: Amount of chlorine required to react on various water impurities before a 

residual is obtained. Also, means the amount of chlorine required to produce a free chlorine residual of 

0.1 mg/l after a contact time of fifteen minutes as measured by iodmetic method of a sample at a 

temperature of twenty degrees in conformance with Standard methods. 

CHLORINE FEED: Chlorine may be delivered by vacuum-controlled solution feed chlorinators. The 

chlorine gas is controlled, metered, introduced into a stream of injector water and then conducted as a 

solution to the point of application. 

CHLORINE, FREE: Chlorine available to kill bacteria or algae. The amount of chlorine available for 

sanitization after the chlorine demand has been met. Also known as chlorine residual. 

CIRCULATION: The continual flow of drilling fluid from injection to recovery and recirculation at the 

surface. 

CLEAR WELL: A large underground storage facility sometimes made of concrete. A clear well or a 

plant storage reservoir is usually filled when demand is low. The final step in the conventional filtration 

process, the clearwell provides temporary storage for the treated water. The two main purposes for this 

storage are to have filtered water available for backwashing the filter and to provide detention time (or 

contact time) for the chlorine (or other disinfectant) to kill any microorganisms that may remain in the 

water. 

ClO2: The molecular formula of Chlorine dioxide. 

COAGULATION: The best pH range for coagulation is between 5 and 7. Mixing is an important part of 

the coagulation process you want to complete the coagulation process as quickly as possible. 

COBBLES: A rock smaller than a boulder but larger than a pebble. A cobble is greater than 2.5 inches 

in diameter and smaller than 10 inches in diameter. 

COLIFORM: Bacteria normally found in the intestines of warm-blooded animals. Coliform bacteria are 

present in high numbers in animal feces. They are an indicator of potential contamination of water. 

Adequate and appropriate disinfection effectively destroys coliform bacteria. Public water systems are 

required to deliver safe and reliable drinking water to their customers 24 hours a day, 365 days a year. 

If the water supply becomes contaminated, consumers can become seriously ill. Fortunately, public 

water systems take many steps to ensure that the public has safe, reliable drinking water. One of the 

most important steps is to regularly test the water for coliform bacteria. Coliform bacteria are organisms 

that are present in the environment and in the feces of all warm-blooded animals and humans. Coliform 

bacteria will not likely cause illness. However, their presence in drinking water indicates that diseasecausing 

organisms (pathogens) could be in the water system. Most pathogens that can contaminate 

water supplies come from the feces of humans or animals. Testing drinking water for all possible 

pathogens is complex, time-consuming, and expensive. It is relatively easy and inexpensive to test for 

coliform bacteria. If coliform bacteria are found in a water sample, water system operators work to find 

the source of contamination and restore safe drinking water. There are three different groups of coliform 

bacteria; each has a different level of risk. 

COLIFORM TESTING: The effectiveness of disinfection is usually determined by Coliform bacteria 

testing. A positive sample is a bad thing and indicates that you have bacteria contamination. 

COLLOIDAL SUSPENSIONS: Because both iron and manganese react with dissolved oxygen to form 

insoluble compounds, they are not found in high concentrations in waters containing dissolved oxygen 

except as colloidal suspensions of the oxide. 

COLORIMETRIC MEASUREMENT: A means of measuring an unknown chemical concentration in 

water by measuring a sample's color intensity. 

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COMMUTATOR: A device for reversing the direction of a current. (in a DC motor or generator) a 

cylindrical ring or disk assembly of conducting members, individually insulated in a supporting structure 

with an exposed surface for contact with current-collecting brushes and mounted on the armature shaft, 

for changing the frequency or direction of the current in the armature windings. 

CHRONIC: A stimulus that lingers or continues for a relatively long period of time, often one-tenth of the 

life span or more. Chronic should be considered a relative term depending on the life span of an 

organism. The measurement of chronic effect can be reduced growth, reduced reproduction, etc., in 

addition to lethality. 

COMBINED CHLORINE: The reaction product of chlorine with ammonia or other pollutants, also known 

as chloramines. 

COMMUNITY WATER SYSTEM: A water system which supplies drinking water to 25 or more of the 

same people year-round in their residences. 

COMPLIANCE CYCLE: A 9-calendar year time-frame during which a public water system is required to 

monitor. Each compliance cycle consists of 3 compliance periods. 

COMPLAINCE PERIOD: A 3-calendar year time-frame within a compliance cycle. 

COMPLETION (WELL COMPLETION): Refers to the final construction of the well including the 

installation of pumping equipment. 

COMPOSITE SAMPLE: A water sample that is a combination of a group of samples collected at 

various intervals during the day. 

CONDENSATION: The process that changes water vapor to tiny droplets or ice crystals. 

CONE OF DEPRESSION: That portion of the water table or potentiometric surface that experiences 

drawdown from a pumped well. 

CONFINED AQUIFER: An aquifer that is isolated by confining layers on both its top and bottom. 

Pressures within a confined aquifer are normally greater than atmospheric pressure resulting in a 

potentiometric head. 

CONFINING LAYER: An extensive layer of soil or formation that resists the movement of water from 

an aquifer below or above it. Confining layers isolate aquifers thereby confining them. May or may not 

be an aquiclude. (ex – Clay or silt rich layer) 

CONSOLIDATED: Soil, sediment, or formation that is solidified or cemented together as a unit. 

CONTACT TIME, pH and LOW TURBIDITY: Factors which are important in providing good disinfection 

using chlorine. 

CONTACT TIME: If the water temperature decreases from 70°F (21°C) to 40°F (4°C). The operator 

needs to increase the detention time to maintain good disinfection of the water. 

CONTAINS THE ELEMENT CARBON: A simple definition of an organic compound. 

CONTAMINANT: Any natural or man-made physical, chemical, biological, or radiological substance or 

matter in water, which is at a level that may have an adverse effect on public health, and which is 

known or anticipated to occur in public water systems. 

CONTAMINATE: tr.v. con·tam·i·nated, con·tam·i·nat·ing, con·tam·i·nates 

1. To make impure or unclean by contact or mixture. 

2. To expose to or permeate with radioactivity. 

CONTAMINATION: A degradation in the quality of groundwater in result of the it’s becoming polluted 

with unnatural or previously non-existent constituents. 

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CONTINUOUS SLOT SCREEN: A wire wrapped or plastic slotted screen in which the slot openings 

completely encircle the inner ribs of the screen. 

CONTROL TASTE AND ODOR PROBLEMS: KMnO4 Potassium permanganate is a strong oxidizer 

commonly used to control taste and odor problems. 

CONVENTIONAL: A standard or common procedure to a group of more complex methods. (ex – 

Direct Rotary conventional vs. Reverse non-conventional) 

COPPER: The chemical name for the symbol Cu. 

CORROSION: The removal of metal from copper, other metal surfaces and concrete surfaces in a 

destructive manner. Corrosion is caused by improperly balanced water or excessive water velocity 

through piping or heat exchangers. 

CORROSIVITY: The Langelier Index measures corrosivity. 

COUPON: A coupon placed to measure corrosion damage in the water mains. 

CROSS-CONNECTION: A physical connection between a public water system and any source of water 

or other substance that may lead to contamination of the water provided by the public water system 

through backflow. Might be the source of an organic substance causing taste and odor problems in a 

water distribution system. 

CROSS-CONTAMINATION: The mixing of two unlike qualities of water. For example, the mixing of 

good water with a polluting substance like a chemical. 

CUTTING HEAD (CUTTER HEAD): The bit portion of auger flighting that serves as the primary cutting 

edge of the auger. 

CUTTING SHOE: A hardened steel sleeve with a wedged or armored cutting edge that is installed on 

well casing that is to be driven into the earth. 

CUTTINGS: Crushed rock, soil, or formation material generated by the drilling action of a bit. 

CRYPTOSPORIDIUM: A disease-causing parasite, resistant to chlorine disinfection. It may be found in 

fecal matter or contaminated drinking water. Cryptosporidium is a protozoan pathogen of the Phylum 

Apicomplexa and causes a diarrheal illness called cryptosporidiosis. Other apicomplexan pathogens 

include the malaria parasite Plasmodium, and Toxoplasma, the causative agent of toxoplasmosis. 

Unlike Plasmodium, which transmits via a mosquito vector, Cryptosporidium does not utilize an insect 

vector and is capable of completing its life cycle within a single host, resulting in cyst stages which are 

excreted in feces and are capable of transmission to a new host. 

CYANURIC ACID: White, crystalline, water-soluble solid, C3H3O3N3·2H2O, used chiefly in organic 

synthesis. Chemical used to prevent the decomposition of chlorine by ultraviolet (UV) light. 

CYANOBACTERIA: Cyanobacteria, also known as blue-green algae, blue-green bacteria or 

Cyanophyta, is a phylum of bacteria that obtain their energy through photosynthesis. The name 

"cyanobacteria" comes from the color of the bacteria (Greek: kyanós = blue). They are a significant 

component of the marine nitrogen cycle and an important primary producer in many areas of the ocean, 

but are also found on land. 

DAILY MAXIMUM LIMITATIONS: The maximum allowable discharge of pollutants during a 24 hour 

period. Where daily maximum limitations are expressed in units of mass, the daily discharge is the total 

mass discharged over the course of the day. Where daily maximum limitations are expressed in terms 

of a concentration, the daily discharge is the arithmetic average measurement of the pollutant 

concentration derived from all measurements taken that day. 

DANGEROUS CHEMICALS: The most suitable protection when working with a chemical that 

produces dangerous fumes is to work under an air hood or fume hood. 

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DARCY’S LAW: (Q=KIA) A fundamental equation used in the groundwater sciences to determine 

aquifer characteristics, where Q=Flux, K=Hydraulic Conductivity (Permeability), I = Hydraulic Gradient 

(change in head), and A = Cross Sectional Area of flow. 

DECIBELS: The unit of measurement for sound. 

DECOMPOSE: To decay or rot. 

DECOMPOSTION OF ORGANIC MATERIAL: The decomposition of organic material in water 

produces taste and odors. 

DEMINERALIZATION PROCESS: Mineral concentration of the feed water is the most important 

consideration in the selection of a demineralization process. Acid feed is the most common method of 

scale control in a membrane demineralization treatment system. 

DENTAL CARIES PREVENTION IN CHILDREN: The main reason that fluoride is added to a water 

supply. 

DEPOLARIZATION: The removal of hydrogen from a cathode. 

DESICCANT: When shutting down equipment which may be damaged by moisture, the unit may be 

protected by sealing it in a tight container. This container should contain a desiccant. 

DESORPTION: Desorption is a phenomenon whereby a substance is released from or through a 

surface. The process is the opposite of sorption (that is, adsorption and absorption). This occurs in a 

system being in the state of sorption equilibrium between bulk phase (fluid, i.e. gas or liquid solution) 

and an adsorbing surface (solid or boundary separating two fluids). When the concentration (or 

pressure) of substance in the bulk phase is lowered, some of the sorbed substance changes to the bulk 

state. In chemistry, especially chromatography, desorption is the ability for a chemical to move with the 

mobile phase. The more a chemical desorbs, the less likely it will adsorb, thus instead of sticking to the 

stationary phase, the chemical moves up with the solvent front. In chemical separation processes, 

stripping is also referred to as desorption as one component of a liquid stream moves by mass transfer 

into a vapor phase through the liquid-vapor interface. 

DEVELOPMENT: The cleaning of the well and bore once construction is complete. 

DETENTION LAG: Is the period of time between the moment of change in a chlorinator control system 

and the moment when the change is sensed by the chlorine residual indicator. 

DETENTION LAG TIME: The minimum detention time range recommended for flocculation is 5 – 20 

minutes for direct filtration and up to 30 minutes for conventional filtration. 

DIATOMACEOUS EARTH: A fine silica material containing the skeletal remains of algae. 

DIRECT CURRENT: A source of direct current (DC) may be used for standby lighting in a water 

treatment facility. The electrical current used in a DC system may come from a battery. 

DIRECT ROTARY: The conventional method of rotary drilling involving the rotation of a drill string and 

standard use of drilling fluid to penetrate the earth. 

DISCHARGE HEAD: See Total Dynamic Head. 

DISINFECT: The application of a chemical to kill most, but not all, microorganisms that may be present. 

Chlorine is added to public water drinking systems drinking water for disinfection. Depending on your 

state rule, drinking water must contain a minimum of 0.2 mg/L free chlorine. Disinfection makes drinking 

water safe to consume from the standpoint of killing pathogenic microorganisms including bacteria and 

viruses. Disinfection does not remove all bacteria from drinking water, but the bacteria that can survive 

disinfection with chlorine are not pathogenic bacteria that can cause disease in normal healthy humans. 

DISINFECTION: The treatment of water to inactivate, destroy, and/or remove pathogenic bacteria, 

viruses, protozoa, and other parasites. 

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DISINFECTION BY-PRODUCTS (DBPs): The products created due to the reaction of chlorine with 

organic materials (e.g. leaves, soil) present in raw water during the water treatment process. The EPA 

has determined that these DBPs can cause cancer. Chlorine is added to drinking water to kill or 

inactivate harmful organisms that cause various diseases. This process is called 

disinfection. However, chlorine is a very active substance and it reacts with naturally occurring 

substances to form compounds known as disinfection byproducts (DBPs). The most common DBPs 

formed when chlorine is used are trihalomethanes (THMs), and haloacetic acids (HAAs). 

DISSOLVED OXYGEN: Can be added to zones within a lake or reservoir that would normally become 

anaerobic during periods of thermal stratification. 

DISSOLUTION : The chemical and physical process of dissolving rock. Typically, limestone or 

carbonate rocks can be dissolved via the percolation or movement of groundwater that, in its infancy, is 

slightly acidic. As time goes on, the rock may also be physically worn away by the rapid movement of 

groundwater through the interconnected open spaces created by the initial chemical dissolving process. 

DISTILLATION, REVERSE OSMOSIS AND FREEZING: Processes that can be used to remove 

minerals from the water. 

DRAG BIT: A style of drill bit used in rotary drilling when soil or formation conditions are loosely 

consolidated and are comprised of fine-grained sediments. 

DRAWDOWN: The change in water level from static to pumping level. 

DRILL COLLAR: A section of the drill string that provides sufficient mass and diameter to maintain 

vertical borehole alignment and consistent borehole diameter. 

DRILL FOAM: Surfactant used in air rotary drilling and well development. 

DRILL PIPE: Sections of the drill string that are connected one to another in order to achieve a desired 

length while also providing a pathway for the circulation of drilling fluid. 

DRILL STEM: The complete drill string or, in cable drilling, the equivalent of a drill collar. 

DRILL STRING: The complete drilling assembly in rotary drilling including drill pipe, subs, collars, and 

bit. 

DRILLER: A specially trained individual that operates the drilling rig. 

DRILLING FLUID: Fluid circulated through the borehole in rotary drilling methods used to lift cuttings to 

the surface, provide borehole stability, and cool the bit. Drilling Fluid may consist of mud, water, air, 

foam, or other additives. 

DRILLING PERMIT: A certificate of approval to drill and construct a well often required by the state or 

local regulating authority. 

DRILLING PRESSURE: The pressure exerted within the borehole during drilling. The pressure 

required to circulate drilling fluid to the surface. 

DRIVE BLOCK: A heavy collar that attaches over the drill pipe and is dropped successively to advance 

casing into the earth. Used primarily in cable tool or percussion drilling methods. 

DRIVE CLAMP: A fitting that is attached to the top of a drill string or stem serving as a striking surface 

for driving casing into the earth. 

DRIVE UNIT: The portion of a rotary rig that provides the rotation to the drill string. (ex – top drive or 

table drive unit). Also may be called the drive head. 

DRIVING: The installation of a well or casing via forcing of it into the earth by repeated striking. 

DRY ACID: A granular chemical used to lower pH and or total alkalinity. 

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E. COLI, Escherichia coli: A bacterium commonly found in the human intestine. For water quality 

analyses purposes, it is considered an indicator organism. These are considered evidence of water 

contamination. Indicator organisms may be accompanied by pathogens, but do not necessarily cause 

disease themselves. 

EFFECTIVENESS OF CHLORINE: The factors which influence the effectiveness of chlorination the 

most are pH, turbidity and temperature. Effectiveness of Chlorine decreases occurs during disinfection 

in source water with excessive turbidity. 

ELECTRON: The name of a negatively charged atomic particle. 

ELEMENTARY BUSINESS PLAN: Technical Capacity, Managerial Capacity, and Financial Capacity 

make up the elementary business plan. To become a new public water system, an owner shall file an 

elementary business plan for review and approval by state environmental agency. 

EMERGENCY RESPONSE TEAM: A local team that is thoroughly trained and equipped to deal with 

emergencies, e.g. chlorine gas leak. In case of a chlorine gas leak, get out of the area and notify your 

local emergency response team in case of a large uncontrolled chlorine leak. 

ENHANCED COAGULATION: The process of joining together particles in water to help remove organic 

matter. 

ENTAMOEBA HISTOLYTICA: Entamoeba histolytica, another water-borne pathogen, can cause 

diarrhea or a more serious invasive liver abscess. When in contact with human cells, these amoebae 

are cytotoxic. There is a rapid influx of calcium into the contacted cell, it quickly stops all membrane 

movement save for some surface blebbing. Internal organization is disrupted, organelles lyse, and the 

cell dies. The ameba may eat the dead cell or just absorb nutrients released from the cell. 

ENTEROVIRUS: A virus whose presence may indicate contaminated water; a virus that may infect the 

gastrointestinal tract of humans. 

EUGLENA: Euglena are common protists, of the class Euglenoidea of the phylum Euglenophyta. 

Currently, over 1000 species of Euglena have been described. Marin et al. (2003) revised the genus so 

and including several species without chloroplasts, formerly classified as Astasia and Khawkinea. 

Euglena sometimes can be considered to have both plant and animal features. Euglena gracilis has a 

long hair-like thing that stretches from its body. You need a very powerful microscope to see it. This is 

called a flagellum, and the euglena uses it to swim. It also has a red eyespot. Euglena gracilis uses its 

eyespot to locate light. Without light, it cannot use its chloroplasts to make itself food. 

EVOLUTION: Any process of formation or growth; development: the evolution of a language; the 

evolution of the airplane. A product of such development; something evolved: The exploration of space 

is the evolution of decades of research. 

Biology. Change in the gene pool of a population from generation to generation by such processes as 

mutation, natural selection, and genetic drift. A process of gradual, peaceful, progressive change or 

development, as in social or economic structure or institutions, a motion incomplete in itself, but 

combining with coordinated motions to produce a single action, as in a machine. A pattern formed by or 

as if by a series of movements: the evolutions of a figure skater. 

F: The chemical symbol of Fluorine. 

FAUCET WITH AN AERATOR: When collecting a water sample from a distribution system, a faucet 

with an aerator should not be used as a sample location. 

FAULT: A break in the earth’s crust where movement has occurred. 

FAULTING: A geological process involving the breaking and displacement of rock or formation through 

movements within the earth’s crust along a fault. 

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FECAL COLIFORM: A group of bacteria that may indicate the presence of human or animal fecal 

matter in water. Total coliform, fecal coliform, and E. coli are all indicators of drinking water quality. The 

total coliform group is a large collection of different kinds of bacteria. Fecal coliforms are types of total 

coliform that mostly exist in feces. E. coli is a sub-group of fecal coliform. When a water sample is sent 

to a lab, it is tested for total coliform. If total coliform is present, the sample will also be tested for either 

fecal coliform or E. coli, depending on the lab testing method. 

FILTRATION: The process of passing water through materials with very small holes to strain out 

particles. Most conventional water treatment plants used filters composed of gravel, sand, and 

anthracite. These materials settle into a compact mass that forms very small holes. Particles are filtered 

out as treated water passes through these holes. These holes are small enough to remove 

microorganisms including algae, bacteria, and protozoans, but not viruses. Viruses are eliminated from 

drinking water through the process of disinfection using chlorine. A series of processes that physically 

removes particles from water. A water treatment step used to remove turbidity, dissolved organics, 

odor, taste and color. 

FILTER CLOGGING: An inability to meet demand may occur when filters are clogging. 

FILTRATION METHODS: The conventional type of water treatment filtration method includes 

coagulation, flocculation, sedimentation, and filtration. Direct filtration method is similar to conventional 

except that the sedimentation step is omitted. Slow sand filtration process does not require 

pretreatment, has a flow of 0.1 gallons per minute per square foot of filter surface area, and is simple to 

operate and maintain. The Diatomaceous earth method uses a thin layer of fine siliceous material on a 

porous plate. This type of filtration medium is only used for water with low turbidity. Sedimentation, 

adsorption, and biological action treatment methods are filtration processes that involve a number of 

interrelated removal mechanisms. Demineralization is primarily used to remove total dissolved solids 

from industrial wastewater, municipal water, and seawater. 

FINISHED WATER: Treated drinking water that meets minimum state and federal drinking water 

regulations. 

FLIGHTING: The spiral flanged drill pipe used in auger drilling. 

FLOATING SUB: A collapsible section of drill pipe shorter than primary drill pipe. Used to provide a 

cushion between the drive unit and the drill string. 

FLOCCULATION: The process of bringing together destabilized or coagulated particles to form larger 

masses that can be settled and/or filtered out of the water being treated. Conventional coagulation– 

flocculation-sedimentation practices are essential pretreatments for many water purification systems— 

especially filtration treatments. These processes agglomerate suspended solids together into larger 

bodies so that physical filtration processes can more easily remove them. Particulate removal by these 

methods makes later filtering processes far more effective. The process is often followed by gravity 

separation (sedimentation or flotation) and is always followed by filtration. A chemical coagulant, such 

as iron salts, aluminum salts, or polymers, is added to source water to facilitate bonding among 

particulates. Coagulants work by creating a chemical reaction and eliminating the negative charges that 

cause particles to repel each other. The coagulant-source water mixture is then slowly stirred in a 

process known as flocculation. This water churning induces particles to collide and clump together into 

larger and more easily removable clots, or “flocs.” The process requires chemical knowledge of source 

water characteristics to ensure that an effective coagulant mix is employed. Improper coagulants make 

these treatment methods ineffective. The ultimate effectiveness of coagulation/flocculation is also 

determined by the efficiency of the filtering process with which it is paired. 

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FLOCCULANTS: Flocculants, or flocculating agents, are chemicals that promote flocculation by 

causing colloids and other suspended particles in liquids to aggregate, forming a floc. Flocculants are 

used in water treatment processes to improve the sedimentation or filterability of small particles. For 

example, a flocculant may be used in swimming pool or drinking water filtration to aid removal of 

microscopic particles which would otherwise cause the water to be cloudy and which would be difficult 

or impossible to remove by filtration alone. Many flocculants are multivalent cations such as aluminum, 

iron, calcium or magnesium. These positively charged molecules interact with negatively charged 

particles and molecules to reduce the barriers to aggregation. In addition, many of these chemicals, 

under appropriate pH and other conditions such as temperature and salinity, react with water to form 

insoluble hydroxides which, upon precipitating, link together to form long chains or meshes, physically 

trapping small particles into the larger floc. 

Long-chain polymer flocculants, such as modified polyacrylamides, are manufactured and sold by the 

flocculant producing business. These can be supplied in dry or liquid form for use in the flocculation 

process. The most common liquid polyacrylamide is supplied as an emulsion with 10-40 % actives and 

the rest is a carrier fluid, surfactants and latex. Emulsion polymers require activation to invert the 

emulsion and allow the electrolyte groups to be exposed. 

FLOC SHEARING: Likely to happen to large floc particles when they reach the flocculation process. 

FLOCCULATION BASIN: A compartmentalized basin with a reduction of speed in each compartment. 

This set-up or basin will give the best overall results. 

FLOOD RIM: The point of an object where the water would run over the edge of something and begin 

to cause a flood. 

FLOW MUST BE MEASURED: A recorder that measures flow is most likely to be located in a central 

location. 

FLUORIDE: High levels of fluoride may stain the teeth of humans. This is called Mottling. This chemical 

must not be overfed due to a possible exposure to a high concentration of the chemical. The most 

important safety considerations to know about fluoride chemicals are that all fluoride chemicals are 

extremely corrosive. These are the substances most commonly used to furnish fluoride ions to water: 

Sodium fluoride, Sodium silicofluoride and Hydrofluosilicic acid. 

FLUORIDE FEEDING: Always review fluoride feeding system designs and specifications to determine 

whether locations for monitoring readouts and dosage controls are convenient to the operation center 

and easy to read and correct. 

FLUX: The term flux describes the rate of water flow through a semipermeable membrane. When the 

water flux decreases through a semipermeable membrane, it means that the mineral concentration of 

the water is increasing. 

FORMATION: A series of layers, deposits, or bodies of rock, which are geologically similar and related 

in depositional environment or origin. A formation can be clearly distinguished relative to bounding 

deposits or formations due to its particular characteristics and composition. 

FORMATION OF TUBERCLES: This condition is of the most concern regarding corrosive water effects 

on a water system. It is the creation of mounds of rust inside the water lines. 

FRACTURE: A discrete break in a rock or formation. 

FRACTURED AQUIFER: An aquifer within and otherwise massive block that has been made 

permeable due to the concentrated presence of fractures typically resultant of faulting or concentrated 

joints. 

FREE CHLORINE: In disinfection, chlorine is used in the form of free chlorine or as hypochlorite ion. 

FREE CHLORINE RESIDUAL: Regardless of whether pre-chloration is practiced or not, a free chlorine 

residual of at least 10 mg/L should be maintained in the clear well or distribution reservoir immediately 

downstream from the point of post-chlorination. The reason for chlorinating past the breakpoint is to 

provide protection in case of backflow. 

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GATE VALVE: The most common type of valve used in isolating a small or medium sized section of a 

distribution system and is the only linear valve used in water distribution. All the other valves are in the 

rotary classification. 

GIARDIA LAMLIA: Giardia lamblia (synonymous with Lamblia intestinalis and Giardia duodenalis) is a 

flagellated protozoan parasite that colonizes and reproduces in the small intestine, causing giardiasis. 

The giardia parasite attaches to the epithelium by a ventral adhesive disc, and reproduces via binary 

fission. Giardiasis does not spread via the bloodstream, nor does it spread to other parts of the gastrointestinal 

tract, but remains confined to the lumen of the small intestine. Giardia trophozoites absorb 

their nutrients from the lumen of the small intestine, and are anaerobes. 

GIARDIASAS, HEPATITIS OR TYHOID: Diseases that may be transmitted through the contamination 

of a water supply but not AIDS. 

GIS – GRAPHIC INFORMATION SYSTEM: Detailed information about the physical locations of 

structures such as pipes, valves, and manholes within geographic areas with the use of satellites. 

GEOTECHNICAL: Characteristics of soil, rock, or formation such as grain size, shear strength, 

porosity, and compressibility, etc. Of particular concern to a geologist or engineer relative to soil or 

aquifer characteristics. 

GLOBE VAVLVE: The main difference between a globe valve and a gate valve is that a globe valve is 

designed as a controlling device. 

GOOD CONTACT TIME, pH and LOW TURBIDITY: These are factors that are important in providing 

good disinfection when using chlorine. 

GPM: Gallons per minute. 

GRAB SAMPLE: A sample which is taken from a water or wastestream on a one-time basis with no 

regard to the flow of the water or wastestream and without consideration of time. A single grab sample 

should be taken over a period of time not to exceed 15 minutes. 

GRAINSIZE: The dimension of particle classifications such as gravel, sand, silt, and clay. Often 

based on the unified soil classification system. 

GROUNDWATER: Water that percolates through and exists within saturated portions of the earth’s 

crust and is replenished by the hydrologic cycle. 

GROUT: A type of cement that is normally fine grained and used to effectively construct well seals and 

used in well abandonment. Grout may also be used to stabilize otherwise unstable boreholes, 

permitting continued drilling. 

GT: Represents (Detention time) x (mixing intensity) in flocculation. 

H2SO4: The molecular formula of Sulfuric acid. 

HALIDES: A halide is a binary compound, of which one part is a halogen atom and the other part is an 

element or radical that is less electronegative than the halogen, to make a fluoride, chloride, bromide, 

iodide, or astatide compound. Many salts are halides. All Group 1 metals form halides with the halogens 

and they are white solids. A halide ion is a halogen atom bearing a negative charge. The halide anions 

are fluoride (F), chloride (Cl), bromide (Br), iodide (I) and astatide (At). Such ions are present in all ionic 

halide salts. 

HALL EFFECT: Refers to the potential difference (Hall voltage) on the opposite sides of an electrical 

conductor through which an electric current is flowing, created by a magnetic field applied perpendicular 

to the current. Edwin Hall discovered this effect in 1879. 

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HALOACETIC ACIDS: Haloacetic acids are carboxylic acids in which a halogen atom takes the place 

of a hydrogen atom in acetic acid. Thus, in a monohaloacetic acid, a single halogen would replace a 

hydrogen atom. For example, chloroacetic acid would have the structural formula CH2ClCO2H. In the 

same manner, in dichloroacetic acid two chlorine atoms would take the place of two hydrogen atoms 

(CHCl2CO2H). 

HAMMER BIT: The bit driven by the hammer to cut into rock or formation. 

HAMMER: See Air Hammer 

HARD ROCK: Consolidated formation or solid rock. 

HARD WATER: Hard water causes a buildup of scale in household hot water heaters. Hard water is a 

type of water that has high mineral content (in contrast with soft water). Hard water primarily consists of 

calcium (Ca2+), and magnesium (Mg2+) metal cations, and sometimes other dissolved compounds 

such as bicarbonates and sulfates. Calcium usually enters the water as either calcium carbonate 

(CaCO3), in the form of limestone and chalk, or calcium sulfate (CaSO4), in the form of other mineral 

deposits. The predominant source of magnesium is dolomite (CaMg(CO3)2). Hard water is generally not 

harmful. The simplest way to determine the hardness of water is the lather/froth test: soap or 

toothpaste, when agitated, lathers easily in soft water but not in hard water. More exact measurements 

of hardness can be obtained through a wet titration. The total water 'hardness' (including both Ca2+ and 

Mg2+ ions) is read as parts per million or weight/volume (mg/L) of calcium carbonate (CaCO3) in the 

water. Although water hardness usually only measures the total concentrations of calcium and 

magnesium (the two most prevalent, divalent metal ions), iron, aluminum, and manganese may also be 

present at elevated levels in some geographical locations. 

HARDNESS: A measure of the amount of calcium and magnesium salts in water. More calcium and 

magnesium lead to greater hardness. The term "hardness" comes from the fact that it is hard to get 

soap suds from soap or detergents in hard water. This happens because calcium and magnesium react 

strongly with negatively-charged chemicals like soap to form insoluble compounds. 

HARTSHORN: The antler of a hart, formerly used as a source of ammonia. Ammonium carbonate. 

HAZARDS OF POLYMERS: Slippery and difficult to clean-up are the most common hazards 

associated with the use of polymers in a water treatment plant. 

HEAD: The measure of the pressure of water expressed in feet of height of water. 1 PSI = 2.31 feet of 

water or 1 foot of head equals about a half a pound of pressure or .433 PSI. There are various types of 

heads of water depending upon what is being measured. Static (water at rest) and Residual (water at 

flow conditions). 

HEADWORKS: The facility at the "head" of the water source where water is first treated and routed into 

the distribution system. 

HEALTH ADVISORY: An EPA document that provides guidance and information on contaminants that 

can affect human health and that may occur in drinking water, but which the EPA does not currently 

regulate in drinking water. 

HERTZ: The term used to describe the frequency of cycles in an alternating current (AC) circuit. 

HETEROTROPHIC PLATE COUNT: A test performed on drinking water to determine the total number 

of all types of bacteria in the water. 

HF: The molecular formula of Hydrofluoric acid. 

HIGH TURBIDITY CAUSING INCREASED CHLORINE DEMAND: May occur or be caused by the 

inadequate disinfection of water. 

HOLLOW STEM (AUGER): An auger form of drilling in which the flighting is hollow. 

HOLLOW STEM FLIGHT: The hollow spiral flanged drill pipe used on hollow stem auger rigs. 

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HOMOPOLAR: Of uniform polarity; not separated or changed into ions; not polar in activity. Electricity. 

unipolar. 

HYDRAULIC CONDUCTIVITY: A primary factor in Darcy’s Law, the measure of a soil or formations 

ability to transmit water, measured in gallons per day (gpd) See also Permeability and Darcy’s Law. 

HYDRIDES: Hydride is the name given to the negative ion of hydrogen, H. Although this ion does not 

exist except in extraordinary conditions, the term hydride is widely applied to describe compounds of 

hydrogen with other elements, particularly those of groups 1–16. The variety of compounds formed by 

hydrogen is vast, arguably greater than that of any other element. Various metal hydrides are currently 

being studied for use as a means of hydrogen storage in fuel cell-powered electric cars and batteries. 

They also have important uses in organic chemistry as powerful reducing agents, and many promising 

uses in hydrogen economy. 

HYDROCHLORIC AND HYPOCHLOROUS ACIDS: HCL and HOCL The compounds that are formed 

in water when chlorine gas is introduced. 

HYDROFLUOSILIC ACID: (H2SiF6) a clear, fuming corrosive liquid with a pH ranging from 1 to 1.5. 

Used in water treatment to fluoridate drinking water. 

HYDROGEN SULFIDE OR CHLORINE GAS: These chemicals can cause olfactory fatigue. 

HYDROLOGIC CYCLE: (Water Cycle) The continual process of precipitation (rain and snowfall), 

evaporation (primarily from the oceans), peculation (recharge to groundwater), runoff (surface water), 

and transpiration (plants) constituting the renew ability and recycling of each component. 

HYDROPHOBIC: Does not mix readily with water. 

HYGROSCOPIC: Absorbing or attracting moisture from the air. 

HYPOCHLORITE (OCL-) AND ORGANIC MATERIALS: Heat and possibly fire may occur when 

hypochlorite is brought into contact with an organic material. 

HYPOLIMNION: The layer of water in a thermally stratified lake that lies below the thermocline, is 

noncirculating, and remains perpetually cold. 

IMPELLERS: The semi-open or closed props or blades of a turbine pump that when rotated generate 

the pumping force. 

IMPERVIOUS: Not allowing, or allowing only with great difficulty, the movement of water. 

IN SERIES: Several components being connected one to the other without a bypass, requiring each 

component to work dependent on the one before it. 

INFILTRATION: The percolation of fluid into soil or formation. See also percolation. 

INFECTIOUS PATHOGENS/MICROBES/GERMS: Are considered disease-producing bacteria, viruses 

and other microorganisms. 

INFLATABLE PACKER: A rubber or fiber bladder device that is inflated to seal against either casing or 

borehole walls. 

INFORMATION COLLECTION RULE: ICR EPA collected data required by the Information Collection 

Rule (May 14, 1996) to support future regulation of microbial contaminants, disinfectants, and 

disinfection byproducts. The rule was intended to provide EPA with information on chemical byproducts 

that form when disinfectants used for microbial control react with chemicals already present in source 

water (disinfection byproducts (DBPs)); disease-causing microorganisms (pathogens), including 

Cryptosporidium; and engineering data to control these contaminants. 

INITIAL MONITORING YEAR: An initial monitoring year is the calendar year designated by the 

Department within a compliance period in which a public water system conducts initial monitoring at a 

point of entry. 

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INORGANIC CONTAMINANTS: Mineral-based compounds such as metals, nitrates, and asbestos. 

These contaminants are naturally-occurring in some water, but can also get into water through farming, 

chemical manufacturing, and other human activities. EPA has set legal limits on 15 inorganic 

contaminants. 

INORGANIC IONS: Present in all waters. Inorganic ions are essential for human health in small 

quantities, but in larger quantities they can cause unpleasant taste and odor or even illness. Most 

community water systems will commonly test for the concentrations of seven inorganic ions: nitrate, 

nitrite, fluoride, phosphate, sulfate, chloride, and bromide. Nitrate and nitrite can cause an illness in 

infants called methemoglobinemia. Fluoride is actually added to the drinking water in some public water 

systems to promote dental health. Phosphate, sulfate, chloride, and bromide have little direct effect on 

health, but high concentrations of inorganic ions can give water a salty or briny taste. 

INSOLUBLE COMPOUNDS: Are types of compounds cannot be dissolved. When iron or manganese 

reacts with dissolved oxygen (DO) insoluble compound are formed. 

INTAKE FACILITIES: One of the more important considerations in the construction of intake facilities is 

the ease of operation and maintenance over the expected lifetime of the facility. Every intake structure 

must be constructed with consideration for operator safety and for cathodic protection. 

ION EXCHANGE: An effective treatment process used to remove iron and manganese in a water 

supply. The hardness of the source water affects the amount of water an ion exchange softener may 

treat before the bed requires regeneration. 

IRON: Fe The elements iron and manganese are undesirable in water because they cause stains and 

promote the growth of iron bacteria. 

IRON AND MANGANESE: Fe and Mn In water they can usually be detected by observing the color of 

the inside walls of filters and the filter media. If the raw water is pre-chlorinated, there will be black 

stains on the walls below the water level and a black coating over the top portion of the sand filter bed. 

When significant levels of dissolved oxygen are present, iron and manganese exist in an oxidized state 

and normally precipitate into the reservoir bottom sediments. The presence of iron and manganese in 

water promote the growth of Iron bacteria. Only when a water sample has been acidified then you can 

perform the analysis beyond the 48 hour holding time. Iron and Manganese in water may be detected 

by observing the color of the of the filter media. Maintaining a free chlorine residual and regular flushing 

of water mains may control the growth of iron bacteria in a water distribution system. 

IRON BACTERIA: Perhaps the most troublesome consequence of iron and manganese in the water is 

they promote the growth of a group of microorganism known as Iron Bacteria. 

IRON FOULING: You should look for an orange color on the resin and backwash water when checking 

an ion exchange unit for iron fouling 

JARS (DRILLING JARS): Metal sections of a drill string that when released provide a jarring force or 

action to aid in removing drill string. Used primarily in cable tool or percussion drilling methods. 

JETTING: The process of injecting high velocity streams of water and/or air through a system of 

nozzles or jets into the well screen and filter pack for well development. 

KARST TOPOGRAPHY: The visual presence of karst on the surface. 

KARST: The presence of caverns, voids, sink holes as characteristic features of a weathered 

limestone or other carbonate formation on or beneath the surface. 

KELLY: A multi-faceted section of drill pipe driven by a kelly drive (table or top drive). 

KILL = C X T: Where other factors are constant, the disinfecting action may be represented by: Kill=C x 

T. C= Chlorine T= Contact time. 

KINETIC ENERGY: The ability of an object to do work by virtue of its motion. The energy terms that are 

used to describe the operation of a pump are pressure and head. 

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LACRIMATION: The secretion of tears, esp. in abnormal abundance Also, lachrymation, lachrimation. 

LANGELIER INDEX: A measurement of Corrosivity. The water is becoming corrosive in the distribution 

system causing rusty water if the Langelier index indicates that the pH has decreased from the 

equilibrium point. Mathematically derived factor obtained from the values of calcium hardness, total 

alkalinity, and pH at a given temperature. A Langelier index of zero indicates perfect water balance (i.e., 

neither corroding nor scaling). The Langelier Saturation Index (sometimes Langelier Stability Index) is a 

calculated number used to predict the calcium carbonate stability of water. It indicates whether the 

water will precipitate, dissolve, or be in equilibrium with calcium carbonate. Langelier developed a 

method for predicting the pH at which water is saturated in calcium carbonate (called pHs). The LSI is 

expressed as the difference between the actual system pH and the saturation pH. 

LSI = pH - pHs 

LEACHING: A chemical reaction between water and metals that allows for removal of soluble 

materials. 

LEAD AND COPPER: Initial tap water monitoring for lead and copper must be conducted during 2 

consecutive 6-month periods. 

LIME: Is a chemical that may be added to water to reduce the corrosivity. When an operator adds lime 

to water, Calcium and magnesium become less soluble. 

LIME SODA SOFTENING: In a lime soda softening process, to the pH of the water is raised to 11.0. In 

a lime softening process, excess lime is frequently added to remove Calcium and Magnesium 

Bicarbonate. The minimum hardness which can be achieved by the lime-soda ash process is 30 to 40 

mg/L as calcium carbonate. The hardness due to noncarbonate hardness is most likely to determine the 

choice between lime softening and ion exchange to remove hardness. 

LIME SOFTENING: Lime softening is primarily used to “soften” water—that is to remove calcium and 

magnesium mineral salts. But it also removes harmful toxins like radon and arsenic. Though there is no 

consensus, some studies have even suggested that lime softening is effective at removal of Giardia. 

Hard water is a common condition responsible for numerous problems. Users often recognize hard 

water because it prevents their soap from lathering properly. However, it can also cause buildup 

(“scale”) in hot water heaters, boilers, and hot water pipes. Because of these inconveniences, many 

treatment facilities use lime softening to soften hard water for consumer use. Before lime softening can 

be used, managers must determine the softening chemistry required. This is a relatively easy task for 

groundwater sources, which remain more constant in their composition. Surface waters, however, 

fluctuate widely in quality and may require frequent changes to the softening chemical mix. In lime 

softening, lime and sometimes sodium carbonate are added to the water as it enters a combination 

solids contact clarifier. This raises the pH (i.e., increases alkalinity) and leads to the precipitation of 

calcium carbonate. Later, the pH of the effluent from the clarifier is reduced again, and the water is then 

filtered through a granular media filter. The water chemistry requirements of these systems require 

knowledgeable operators, which may make lime softening an economic challenge for some very small 

systems. 

LINE SHAFT TURBINE: See vertical turbine. 

LOGGED (LOGGING): The assessment and documentation of geological and water production data 

obtained while drilling progresses or following drilling through the use of borehole geophysical logging 

tools. 

L.O.T.O.: Lock Out, Tag Out. If a piece of equipment is locked out, the key to the lock-out device the 

key should be held by the person who is working on the equipment. The tag is an identification device 

and the lock is a physical restraint. 

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M-ENDO BROTH: The coliform group is used as indicators of fecal pollution in water, for assessing the 

effectiveness of water treatment and disinfection, and for monitoring water quality. m-Endo Broth is 

used for selectively isolating coliform bacteria from water and other specimens using the membrane 

filtration technique. m-Endo Broth is prepared according to the formula of Fifield and Schaufus.1 It is 

recommended by the American Public Health Association in standard total coliform membrane filtration 

procedure for testing water, wastewater, and foods.2,3 The US EPA specifies using m-Endo Broth in 

the total coliform methods for testing water using single-step, two-step, and delayed incubation 

membrane filtration methods. 

MAGNESIUM HARDNESS: Measure of the magnesium salts dissolved in water – it is not a factor in 

water balance. 

MAGNETIC STARTER: Is a type of motor starter should be used in an integrated circuit to control flow 

automatically. 

MARBLE AND LANGELIER TESTS: Are used to measure or determine the corrosiveness of a water 

source. 

MAXIMUM CONTAMINANT LEVEL (MCLs): The maximum allowable level of a contaminant that 

federal or state regulations allow in a public water system. If the MCL is exceeded, the water system 

must treat the water so that it meets the MCL. 

MAXIMUM CONTAMINANT LEVEL GOAL (MCLG): The level of a contaminant at which there would 

be no risk to human health. This goal is not always economically or technologically feasible, and the 

goal is not legally enforceable. 

MCL for TURBIDITY: Turbidity is undesirable because it causes health hazards. An MCL for turbidity 

was established by the EPA because turbidity does not allow for proper disinfection. 

MEASURE CORROSION DAMAGE: A coupon such as a strip of metal and is placed to measure 

corrosion damage in the distribution system in a water main. 

MECHANICAL SEAL: A mechanical device used to control leakage from the stuffing box of a pump. 

Usually made of two flat surfaces, one of which rotates on the shaft. The two flat surfaces are of such 

tolerances as to prevent the passage of water between them. Held in place with spring pressure. 

MEDIUM WATER SYSTEM: More than 3,300 persons and 50,000 or fewer persons. 

MEGGER: Is a portable instrument used to measure insulation resistance. The megger consists of a 

hand-driven DC generator and a direct reading ohm meter. Used to test the insulation resistance on a 

motor. 

M-ENDO BROTH: The media shall be brought to the boiling point when preparing M-Endo broth to be 

used in the membrane filter test for total coliform. 

METALIMNION: Thermocline, middle layer of a thermally stratified lake which is characterized by a 

rapid decrease in temperature in proportion to depth. 

METALLOID: Metalloid is a term used in chemistry when classifying the chemical elements. On the 

basis of their general physical and chemical properties, nearly every element in the periodic table can 

be termed either a metal or a nonmetal. A few elements with intermediate properties are, however, 

referred to as metalloids. (In Greek metallon = metal and eidos = sort) 

METHANE: Methane is a chemical compound with the molecular formula CH4. It is the simplest alkane, 

and the principal component of natural gas. Methane's bond angles are 109.5 degrees. Burning 

methane in the presence of oxygen produces carbon dioxide and water. The relative abundance of 

methane and its clean burning process makes it a very attractive fuel. However, because it is a gas at 

normal temperature and pressure, methane is difficult to transport from its source. In its natural gas 

form, it is generally transported in bulk by pipeline or LNG carriers; few countries still transport it by 

truck. 

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MILLILITER: One one-thousandth of a liter; A liter is a little more than a quart. A milliliter is 

about two drops from an eye dropper. 

Mg/L: Stands for "milligrams per liter." A common unit of chemical concentration. It expresses 

the mass of a chemical that is present in a given volume of water. A milligram (one onethousandth 

of a gram) is equivalent to about 18 grains of table salt. A liter is equivalent to about 

one quart. 

MICROBIOLOGICAL: Is a type of analysis in which a composite sample unacceptable. 

MICROBE OR MICROBIAL: Any minute, simple, single-celled form of life, especially one that causes 

disease. 

MICROBIAL CONTAMINANTS: Microscopic organisms present in untreated water that can cause 

waterborne diseases. 

MICROORGANISMS: Very small animals and plants that are too small to be seen by the naked eye 

and must be observed using a microscope. Microorganisms in water include algae, bacteria, viruses, 

and protozoa. Algae growing in surface waters can cause off-taste and odor by producing the chemicals 

MIB and geosmin. Certain types of bacteria, viruses, and protozoa can cause disease in humans. 

Bacteria are the most common microorganisms found in treated drinking water. The great majority of 

bacteria are not harmful. In fact, humans would not be able to live without the bacteria that inhabit the 

intestines. However, certain types of bacteria called coliform bacteria can signal the presence of 

possible drinking water contamination. 

MILLILITER: One one-thousandth of a liter. A liter is a little more than a quart. A milliliter is about two 

drops from an eye dropper. 

MOISTURE: If a material is hygroscopic, it must it be protected from water. 

MOISTURE AND POTASSIUM PERMANGANATE: The combination of moisture and potassium 

permanganate produces heat. 

MOLECULAR WEIGHT: The molecular mass (abbreviated Mr) of a substance, formerly also called 

molecular weight and abbreviated as MW, is the mass of one molecule of that substance, relative to the 

unified atomic mass unit u (equal to 1/12 the mass of one atom of carbon-12). This is distinct from the 

relative molecular mass of a molecule, which is the ratio of the mass of that molecule to 1/12 of the 

mass of carbon 12 and is a dimensionless number. Relative molecular mass is abbreviated to Mr. 

MOTTLING: High levels of fluoride may stain the teeth of humans. 

M.S.D.S.: Material Safety Data Sheet. A safety document must an employer provide to an operator 

upon request. 

MUD BALLS IN FILTER MEDIA: Is a possible result of an ineffective or inadequate filter backwash. 

MUD CAKE: A film of mud drilling fluid that builds up on borehole walls adding to borehole stability and 

limits the groundwater’s ability to enter the borehole while drilling. 

MUD CAKING: The process of building up the mud cake. 

MUD ENGINEER: A specially trained individual who’s responsible for maintaining proper drilling fluid 

densities and viscosity. 

MUD PIT: Single or multiple subsurface or surface containment system used for settling cuttings out of 

drilling fluid and for recirculation of drilling fluid. 

MUD PUMP: A specially designed pump that can pass particles of mud and cuttings (drilling fluid) at 

variable pressures, serving as the primary component in a mud rotary drilling system (similar to a grout 

or cement pump). 

MUD ROTARY: The method of rotary drilling with mud circulation as the drilling fluid. 

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MURIATIC ACID: An acid used to reduce pH and alkalinity. Also used to remove stain and scale. 

MYCOTOXIN: A toxin produced by a fungus. 

NaOCl: Is the molecular formula of Sodium hypochlorite. 

NaOH: Is the molecular formula of Sodium hydroxide. 

NASCENT: Coming into existence; emerging. 

NATURAL GRAVEL PACK (NATURALLY PACKED): Refers to a well that has no gravel pack 

installed but is simply allowed to develop a filter pack composed of the aquifer particles itself. Usually 

coarse grained and hard rock aquifers are naturally packed. 

NH3: The molecular formula of Ammonia. 

NH4+: The molecular formula of the Ammonium ion. 

NITRATES: A dissolved form of nitrogen found in fertilizers and sewage by-products that may leach 

into groundwater and other water sources. Nitrates may also occur naturally in some waters. Over time, 

nitrates can accumulate in aquifers and contaminate groundwater. 

NITROGEN: Nitrogen is a nonmetal, with an electronegativity of 3.0. It has five electrons in its outer 

shell and is therefore trivalent in most compounds. The triple bond in molecular nitrogen (N2) is one of 

the strongest in nature. The resulting difficulty of converting (N2) into other compounds, and the ease 

(and associated high energy release) of converting nitrogen compounds into elemental N2, have 

dominated the role of nitrogen in both nature and human economic activities. 

NITROGEN AND PHOSPHORUS: Pairs of elements and major plant nutrients that cause algae to 

grow. 

NO3 - : The molecular formula of the Nitrate ion. 

NON-CARBONATE HARDNESS: The portion of the total hardness in excess of the alkalinity. 

NON-CARBONATE IONS: Water contains non-carbonate ions if it cannot be softened to a desired level 

through the use of lime only. 

NON-POINT SOURCE POLLUTION: Air pollution may leave contaminants on highway surfaces. This 

non-point source pollution adversely impacts reservoir water and groundwater quality. 

NON-TRANSIENT, NON-COMMUNITY WATER SYSTEM: A water system which supplies water to 25 

or more of the same people at least six months per year in places other than their residences. Some 

examples are schools, factories, office buildings, and hospitals which have their own water systems. 

NORMALITY: It is the number of equivalent weights of solute per liter of solution. Normality highlights 

the chemical nature of salts: in solution, salts dissociate into distinct reactive species (ions such as H + , 

Fe3 + , or Cl - ). Normality accounts for any discrepancy between the concentrations of the various ionic 

species in a solution. For example, in a salt such as MgCl2, there are two moles of Cl - for every mole of 

Mg2 + , so the concentration of Cl- as well as of Mg2 + is said to be 2 N (read: "two normal"). Further 

examples are given below. A normal is one gram equivalent of a solute per liter of solution. The 

definition of a gram equivalent varies depending on the type of chemical reaction that is discussed - it 

can refer to acids, bases, redox species, and ions that will precipitate. It is critical to note that normality 

measures a single ion which takes part in an overall solute. For example, one could determine the 

normality of hydroxide or sodium in an aqueous solution of sodium hydroxide, but the normality of 

sodium hydroxide itself has no meaning. Nevertheless it is often used to describe solutions of acids or 

bases, in those cases it is implied that the normality refers to the H+ or OH- ion. For example, 2 Normal 

sulfuric acid (H2SO4), means that the normality of H+ ions is 2, or that the molarity of the sulfuric acid is 

1. Similarly for 1 Molar H3PO4 the normality is 3 as it contains three H+ ions. 

NTNCWS: Non-transient non-community water system. 

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NTU (Nephelometric turbidity unit): A measure of the clarity or cloudiness of water. 

O3: The molecular formula of ozone. 

OIL TUBE: A tubular enclosure that houses the line shaft and bearings of a vertical turbine pump. Oil 

is allowed to pass through the oil tube in order to lubricate the pumps drive shaft and bearings. 

OLIGOTROPHIC: A reservoir that is nutrient-poor and contains little plant or animal life. An oligotrophic 

ecosystem or environment is one that offers little to sustain life. The term is commonly utilized to 

describe bodies of water or soils with very low nutrient levels. It derives etymologically from the Greek 

oligo (small, little, few) and trophe (nutrients, food). Oligotrophic environments are of special interest for 

the alternative energy sources and survival strategies upon which life could rely. 

ORGANIC PRESURSORS: Natural or man-made compounds with chemical structures based upon 

carbon that, upon combination with chlorine, leading to trihalomethane formation. 

OSMOSIS: Osmosis is the process by which water moves across a semi permeable membrane from a 

low concentration solute to a high concentration solute to satisfy the pressure differences caused by the 

solute. 

OVERBURDEN: Normally a thin loosely consolidated or unconsolidated sediment overlying competent 

formation. 

OVER-RANGE PROTECTION DEVICES: Mechanical dampers, snubbers and an air cushion chamber 

are examples of surging and overrange protection devices. 

OXIDE: An oxide is a chemical compound containing at least one oxygen atom as well as at least one 

other element. Most of the Earth's crust consists of oxides. Oxides result when elements are oxidized by 

oxygen in air. Combustion of hydrocarbons affords the two principal oxides of carbon, carbon monoxide 

and carbon dioxide. Even materials that are considered to be pure elements often contain a coating of 

oxides. For example, aluminum foil has a thin skin of Al2O3 that protects the foil from further corrosion. 

OXIDIZED: 

1. to convert (an element) into an oxide; combine with oxygen. 

2. to cover with a coating of oxide or rust. 

3. to take away hydrogen, as by the action of oxygen; add oxygen or any nonmetal. 

4. to remove electrons from (an atom or molecule), thereby increasing the valence. Compare REDUCE 

(def. 12). 

–verb (used without object) 

5. to become oxidized. 

OXIDIZING: The process of breaking down organic wastes into simpler elemental forms or by products. 

Also used to separate combined chlorine and convert it into free chlorine. 

OXYGEN DEFICIENT ENVIRONMENT: One of the most dangerous threats to an operator upon 

entering a manhole. 

OZONE: Ozone or trioxygen (O3) is a triatomic molecule, consisting of three oxygen atoms. It is an 

allotrope of oxygen that is much less stable than the diatomic O2. Ground-level ozone is an air pollutant 

with harmful effects on the respiratory systems of animals. Ozone in the upper atmosphere filters 

potentially damaging ultraviolet light from reaching the Earth's surface. It is present in low 

concentrations throughout the Earth's atmosphere. It has many industrial and consumer applications. 

Ozone, the first allotrope of a chemical element to be recognized by science, was proposed as a distinct 

chemical compound by Christian Friedrich Schönbein in 1840, who named it after the Greek word for 

smell (ozein), from the peculiar odor in lightning storms. The formula for ozone, O3, was not determined 

until 1865 by Jacques-Louis Soret and confirmed by Schönbein in 1867. Ozone is a powerful oxidizing 

agent, far better than dioxygen. It is also unstable at high concentrations, decaying to ordinary diatomic 

oxygen (in about half an hour in atmospheric conditions): 

2 O3 = 3 O2 

This reaction proceeds more rapidly with increasing temperature and decreasing pressure. Deflagration 

of ozone can be triggered by a spark, and can occur in ozone concentrations of 10 wt% or higher. 

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OZONE DOES NOT PROVIDE A RESIDUAL: One of the major drawbacks to using ozone as a 

disinfectant. 

OZONE, CHLORINE DIOXIDE, UV, CHLORAMINES: These chemicals may be used as alternative 

disinfectants. 

PAC: A disadvantage of using PAC is it is very abrasive and requires careful maintenance of 

equipment. One precaution that should be taken in storing PAC is that bags of carbon should not be 

stored near bags of HTH. Removes tastes and odors by adsorption only. Powered activated carbon 

frequently used for taste and odor control because PAC is non-specific and removes a broad range of 

compounds. Jar tests and threshold odor number testing determines the application rate for powdered 

activated carbon. Powdered activated carbon, or PAC, commonly used for in a water treatment plant for 

taste and odor control. Powdered activated carbon may be used with some success in removing the 

precursors of THMs 

PACKING: Material, usually of woven fiber, placed in rings around the shaft of a pump and used to 

control the leakage from the stuffing box. 

PARAMECIUM: Paramecia are a group of unicellular ciliate protozoa formerly known as slipper 

animalcules from their slipper shape. They are commonly studied as a representative of the ciliate 

group. Simple cilia cover the body which allows the cell to move with a synchronous motion (like a 

caterpilla). There is also a deep oral groove containing inconspicuous compound oral cilia (as found in 

other peniculids) that is used to draw food inside. They generally feed upon bacteria and other small 

cells. Osmoregulation is carried out by a pair of contractile vacuoles, which actively expel water 

absorbed by osmosis from their surroundings. Paramecia are widespread in freshwater environments, 

and are especially common in scums. Paramecia are attracted by acidic conditions. Certain singlecelled 

eukaryotes, such as Paramecium, are examples for exceptions to the universality of the genetic 

code (translation systems where a few codons differ from the standard ones). 

PATHOGENS: Disease-causing pathogens; waterborne pathogens A pathogen may contaminate water 

and cause waterborne disease. 

Pb: The chemical symbol of Lead. 

PCE: Perchloroethylene. Known also as perc or tetrachloroethylene, perchloroethylene is a clear, 

colorless liquid with a distinctive, somewhat ether-like odor. It is non-flammable, having no measurable 

flashpoint or flammable limits in air. Effective over a wide range of applications, perchloroethylene is 

supported by closed loop transfer systems, stabilizers and employee exposure monitoring. 

PEAK DEMAND: The maximum momentary load placed on a water treatment plant, pumping station or 


PERCOLATION: The process of fluid penetrating or slowly flowing through soil, rock, or formation. 

See also infiltration. 

PERCUSSION RIG: See Cable Tool. 

PERFORATED SCREEN: Well screen that has openings mechanically cut into it. 

PERFORMANCE CURVE: A graphical representation of a pumps efficiency relative to gpm and feet of 

head. 

PEPTIDOGLYCAN: A polymer found in the cell walls of prokaryotes that consists of polysaccharide 

and peptide chains in a strong molecular network. Also called mucopeptide, murein. 

PERMEATE: The term for water which has passed through the membrane of a reverse osmosis unit. 

PERMEABILITY: A measure of a soil or formation’s capacity to transmit water, typically in volume per 

time units. Equivalent to Darcy’s hydraulic conductivity. 

PERMEABLE: Soil or formation of which water can pass through. 

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pH: A unit of measure which describes the degree of acidity or alkalinity of a solution. The pH scale 

runs from 0 to 14 with 7 being the mid-point or neutral. A pH of less than 7 is on the acid side of the 

scale with 0 as the point of greatest acid activity. A pH of more than 7 is on the basic (alkaline) side of 

the scale with 14 as the point of greatest basic activity. The term pH is derived from “p”, the 

mathematical symbol of the negative logarithm, and “H”, the chemical symbol of Hydrogen. The 

definition of pH is the negative logarithm of the Hydrogen ion activity. pH=-log[H + ]. 

pH OF SATURATION: The ideal pH for perfect water balance in relation to a particular total alkalinity 

level and a particular calcium hardness level, at a particular temperature. The pH where the Langelier 

Index equals zero. 

PHENOLPHTHALEIN/TOTAL ALKALINITY: The relationship between the alkalinity constituent’s 

bicarbonate, carbonate, and hydroxide can be based on the P and T alkalinity measurement. 

PHENOL RED: Chemical reagent used for testing pH in the range of 6.8 - 8.4. 

PHOSPHATE, NITRATE AND ORGANIC NITROGEN: Nutrients in a domestic water supply reservoir 

may cause water quality problems if they occur in moderate or large quantities. 

PHYSISORPTION: (Or physical adsorption) Is adsorption in which the forces involved are 

intermolecular forces (van der Waals forces) of the same kind as those responsible for the imperfection 

of real gases and the condensation of vapors, and which do not involve a significant change in the 

electronic orbital patterns of the species involved. The term van der Waals adsorption is synonymous 

with physical adsorption, but its use is not recommended. 

PICOCURIE: A unit of radioactivity. "Pico" is a metric prefix that means one one-millionth of one onemillionth. 

A picocurie is one one-millionth of one one-millionth of a Curie. A Curie is that quantity of any 

radioactive substance that undergoes 37 billion nuclear disintegrations per second. Thus a picocurie is 

that quantity of any radioactive substance that undergoes 0.037 nuclear disintegrations per second. 

pCi/L: Picocuries per liter A curie is the amount of radiation released by a set amount of a certain 

compound. A picocurie is one quadrillionth of a curie. 

PICOCURIE: A unit of radioactivity. "Pico" is a metric prefix that means one one-millionth of one onemillionth. 

A picocurie is one one-millionth of one one-millionth of a Curie. A Curie is that quantity of any 

radioactive substance that undergoes 37 billion nuclear disintegrations per second. Thus a picocurie is 

that quantity of any radioactive substance that undergoes 0.037 nuclear disintegrations per second. 

PIEZOMETRIC SURFACE: See potentiometric surface. 

PILOT BIT: A bit used on auger rigs to cut a pilot hole ahead of the cutter head when drilling into more 

resistant formations. 

PIPELINE APPURTENANCE: Pressure reducers, bends, valves, regulators (which are a type of 

valve), etc. 

PITLESS ADAPTER: A fitting installed on a section of column pipe and well casing permitting piping 

from the well to be installed below grade. (Often requires a special permit for construction) 

PLANKTON: The aggregate of passively floating, drifting, or somewhat motile organisms occurring in a 

body of water, primarily comprising microscopic algae and protozoa. 

PLATFORM: The portion of the drilling rig where a driller and crew operate the drill rig. 

PLUG: A removable cap installed behind the pilot and cutter bits on hollow stem auger flighting. 

POINT OF ENTRY: POE. 

POLLUTION: To make something unclean or impure. See Contaminated. 

POLYPHOSPHATES: Chemicals that may be added to remove low levels of iron and manganese. 

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POLYMER: A type of chemical when combined with other types of coagulants aid in binding small 

suspended particles to larger particles to help in the settling and filtering processes. 

PORE SPACE: The interstitial space between sediments and fractures that is capable of storing and 

transmitting water. 

POROSITY: A factor representing a rock, soil, or formations percentage of open space available for the 

percolation and storage of groundwater. 

POST-CHLORINE: Where the water is chlorinated to make sure it holds a residual in the distribution 

system. 

POTABLE: Good water which is safe for drinking or cooking purposes. Non-Potable: A liquid or water 

that is not approved for drinking. 

POTENTIAL ENERGY: The energy that a body has by virtue of its position or state enabling it to do 

work. 

POTENTIOMETRIC SURFACE: An imaginary surface representing the height a column of water will 

reach at any location within a confined aquifer. The measured surface of a confined aquifer related to 

the aquifer’s pressure head. 

PPM: Abbreviation for parts per million. 

PRE-CHLORINE: Where the raw water is dosed with a large concentration of chlorine. 

PRE-CHLORINATION: The addition of chlorine before the filtration process will help: 

> Control algae and slime growth 

> Control mud ball formation 

> Improve coagulation 

> Precipate iron 

The addition of chlorine to the water prior to any other plant treatment processes. 

PERKINESIS: The aggregation resulting from random thermal motion of fluid molecules. 

PRESSURE: Pressure is defined as force per unit area. It is usually more convenient to use pressure 

rather than force to describe the influences upon fluid behavior. The standard unit for pressure is the 

Pascal, which is a Newton per square meter. For an object sitting on a surface, the force pressing on 

the surface is the weight of the object, but in different orientations it might have a different area in 

contact with the surface and therefore exert a different pressure. 

PRESSURE HEAD: The height of a column of water capable of being maintained by pressure. See 

also Total Head, Total Dynamic Head. 

PRESSURE MEASUREMENT: Bourdon tube, Bellows gauge and Diaphragm are commonly used to 

measure pressure in waterworks systems. A Bellows-type sensor reacts to a change in pressure. 

PREVENTION: To take action; stop something before it happens. 

PROTON, NEUTRON AND ELECTRON: Are the 3 fundamental particles of an atom. 

PRODUCING ZONE: A specific productive interval. 

PRODUCTIVE INTERVAL: The portion or portions of an aquifer in which significant water production is 

obtained within the well. 

PROTIST: Any of a group of eukaryotic organisms belonging to the kingdom Protista according to 

some widely used modern taxonomic systems. The protists include a variety of unicellular, coenocytic, 

colonial, and multicellular organisms, such as the protozoans, slime molds, brown algae, and red algae. 

A unicellular protoctist in taxonomic systems in which the protoctists are considered to form a kingdom. 

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PROTOCTIST: Any of various unicellular eukaryotic organisms and their multicellular, coenocytic, or 

colonial descendants that belong to the kingdom Protoctista according to some taxonomic systems. The 

protoctists include the protozoans, slime molds, various algae, and other groups. In many new 

classification systems, all protoctists are considered to be protists. 

PROTOZOA: Microscopic animals that occur as single cells. Some protozoa can cause disease in 

humans. Protozoa form cysts, which are specialized cells like eggs that are very resistant to chlorine. 

Cysts can survive the disinfection process, then "hatch" into normal cells that can cause disease. 

Protozoa must be removed from drinking water by filtration, because they cannot be effectively killed by 

chlorine. 

PUBLIC NOTIFICATION: An advisory that EPA requires a water system to distribute to affected 

consumers when the system has violated MCLs or other regulations. The notice advises consumers 

what precautions, if any, they should take to protect their health. 

PUBLIC WATER SYSTEM (PWS): Any water system which provides water to at least 25 people for at 

least 60 days annually. There are more than 170,000 PWSs providing water from wells, rivers and other 

sources to about 250 million Americans. The others drink water from private wells. There are differing 

standards for PWSs of different sizes and types. 

PUMP SURGING: A process of well development whereby water is pumped nearly to the surface and 

then is allowed to fall back into the well. The process creates a backwashing action that cleans the well 

and nearby formation. 

PUMPING LIFT: The height to which water must be pumped or lifted to, feet of head. 

PWS: 3 types of public water systems. Community water system, non-transient non-community water 

system, transient non community water system. 

RADIOCHEMICALS: (Or radioactive chemicals) Occur in natural waters. Naturally radioactive ores are 

particularly common in the Southwestern United States, and some streams and wells can have 

dangerously high levels of radioactivity. Total alpha and beta radioactivity and isotopes of radium and 

strontium are the major tests performed for radiochemicals. The federal drinking water standard for 

gross alpha radioactivity is set at 5 picocuries per liter. 

RADIUS OF INFLUENCE: The distance away from a pumping well that water levels are affected by a 

wells cone of depression. 

RAWHIDING: See Pump Surging. 

RAW TURBIDITY: The turbidity of the water coming to the treatment plant from the raw water source. 

RAW WATER: Water that has not been treated in any way; it is generally considered to be unsafe to 

drink. 

REAGENT: A substance used in a chemical reaction to measure, detect, examine, or produce other 

substances. 

REAM: The process of enlarging a borehole. 

REAMER BIT: A special bit designed to ream existing boreholes. 

RECHARGE: The infiltration component of the hydrologic cycle. Often used in the context of referring 

to: The infiltration of water back into an aquifer, resulting in the restoration of lost storage and water 

levels which had been decreased due to pumping and/or natural discharges from the aquifer. 

RECIRCULATING SYSTEM: A system of constructed or surface mud pits that settle out cuttings from 

drilling fluid to be circulated back down the borehole. 

RECORDER, FLOW: A flow recorder that measures flow is most likely to be located anywhere in the 

plant where a flow must be measured and in a central location. 

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RED WATER AND SLIME: Iron bacteria are undesirable in a water distribution system because of red 

water and slime complaints. 

REDOX POTENTIAL: Reduction potential (also known as redox potential, oxidation / reduction 

potential or ORP) is the tendency of a chemical species to acquire electrons and thereby be reduced. 

Each species has its own intrinsic reduction potential; the more positive the potential, the greater the 

species' affinity for electrons and tendency to be reduced. In aqueous solutions, the reduction potential 

is the tendency of the solution to either gain or lose electrons when it is subject to change by 

introduction of a new species. A solution with a higher (more positive) reduction potential than the new 

species will have a tendency to gain electrons from the new species (i.e. to be reduced by oxidizing the 

new species) and a solution with a lower (more negative) reduction potential will have a tendency to 

lose electrons to the new species (i.e. to be oxidized by reducing the new species). 

RELAY LOGIC: The name of a popular method of automatically controlling a pump, valve, chemical 

feeder, and other devices. 

RESERVOIR: An impoundment used to store water. 

RESIDUAL DISINFECTION PROTECTION: A required level of disinfectant that remains in treated 

water to ensure disinfection protection and prevent recontamination throughout the distribution system 

(i.e., pipes). 

REVERSE MUD ROTARY: A non-conventional drilling method in which drilling fluid is injected through 

the borehole annulus downward through the bit and circulated back to the surface through the drill 

string. 

REVERSE OSMOSIS: Forces water through membranes that contain holes so small that even salts 

cannot pass through. Reverse osmosis removes microorganisms, organic chemicals, and inorganic 

chemicals, producing very pure water. For some people, drinking highly purified water exclusively can 

upset the natural balance of salts in the body. Reverse osmosis units require regular maintenance or 

they can become a health hazard. 

RIBBED STABILIZER: A stabilizer or drill collar that has cutting ribs attached to its side. Ribs are 

normally installed in vertical or spiral arrangements. 

ROLLER BIT: A rotary drill bit having rotating cutting heads. 

ROTAMETER: The name of transparent tube with a tapered bore containing a ball is often used to 

measure the rate of flow of a gas or liquid. 

ROTARY RIG: A conventional rotary drill rig. Can be either an air or mud rotary rig. 

ROTIFER: Rotifers get their name (derived from Greek and meaning "wheel-bearer"; they have also 

been called wheel animalcules) from the corona, which is composed of several ciliated tufts around the 

mouth that in motion resemble a wheel. These create a current that sweeps food into the mouth, where 

it is chewed up by a characteristic pharynx (called the mastax) containing a tiny, calcified, jaw-like 

structure called the trophi. The cilia also pull the animal, when unattached, through the water. Most freeliving 

forms have pairs of posterior toes to anchor themselves while feeding. Rotifers have bilateral 

symmetry and a variety of different shapes. There is a well-developed cuticle which may be thick and 

rigid, giving the animal a box-like shape, or flexible, giving the animal a worm-like shape; such rotifers 

are respectively called loricate and illoricate. 

RUNOFF: Surface water sources such as a river or lake are primarily the result of natural processes of 

runoff. 

SAFE YIELD: A possible consequence when the “safe yield” of a well is exceeded and water continues 

to be pumped from a well, is land subsidence around the well will occur. Safe yield refers to a long-term 

balance between the water that is naturally and artificially recharged to an aquifer and the groundwater 

that is pumped out. When more water is removed than is recharged, the aquifer is described as being 

out of safe yield. When the water level in the aquifer then drops, we are said to be mining groundwater. 

SALTS ARE ABSENT: Is a strange characteristic that is unique to water vapor in the atmosphere. 

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SAMPLE: The water that is analyzed for the presence of EPA-regulated drinking water contaminants. 

Depending on the regulation, EPA requires water systems and states to take samples from source 

water, from water leaving the treatment facility, or from the taps of selected consumers. 

SAMPLING LOCATION: A location where soil or cuttings samples may be readily and accurately 

collected. 

SAND, ANTHRACITE AND GARNET: Mixed media filters are composed of these three materials. 

SANITARY SURVEY: Persons trained in public health engineering and the epidemiology of 

waterborne diseases should conduct the sanitary survey. The importance of a detailed sanitary survey 

of a new water source cannot be overemphasized. An on-site review of the water sources, facilities, 

equipment, operation, and maintenance of a public water systems for the purpose of evaluating the 

adequacy of the facilities for producing and distributing safe drinking water. The purpose of a nonregulatory 

sanitary survey is to identify possible biological and chemical pollutants which might affect a 

water supply. 

SANITIZER: A disinfectant or chemical which disinfects (kills bacteria), kills algae and oxidizes organic 

matter. 

SATURATION INDEX: See Langelier's Index. 

SATURATOR: A device which produces a fluoride solution for the fluoride process. Crystal-grade types 

of sodium fluoride should be fed with a saturator. Overfeeding must be prevented to protect public 

health when using a fluoridation system. 

SATURATED ZONE: Where an unconfined aquifer becomes saturated beneath the capillary fringe. 

SCADA: A remote method of monitoring pumps and equipment. 130 degrees F is the maximum 

temperature that transmitting equipment is able to with stand. If the level controller may be set with too 

close a tolerance 45 could be the cause of a control system that is frequently turning a pump on and off. 

SCALE: Crust of calcium carbonate, the result of unbalanced water. Hard insoluble minerals deposited 

(usually calcium bicarbonate) which forms on pool and spa surfaces and clog filters, heaters and 

pumps. Scale is caused by high calcium hardness and/or high pH. The regular use of stain prevention 

chemicals can prevent scale. 

SCHMUTZDECKE: German, "grime or filth cover", sometimes spelt schmutzedecke) is a complex 

biological layer formed on the surface of a slow sand filter. The schmutzdecke is the layer that provides 

the effective purification in potable water treatment, the underlying sand providing the support medium 

for this biological treatment layer. The composition of any particular schmutzdecke varies, but will 

typically consist of a gelatinous biofilm matrix of bacteria, fungi, protozoa, rotifera and a range of aquatic 

insect larvae. As a schmutzdecke ages, more algae tend to develop, and larger aquatic organisms may 

be present including some bryozoa, snails and annelid worms. 

SCROLL AND BASKET: The two basic types of centrifuges used in water treatment. 

SEAL: For wells: to abandon a well by filling up the well with approved seal material including 

cementing with grout from a required depth to the land surface. 

SECONDARY DRINKING WATER STANDARDS: Non-enforceable federal guidelines regarding 

cosmetic effects (such as tooth or skin discoloration) or aesthetic effects (such as taste, odor, or color) 

of drinking water. 

SECTIONAL MAP: The name of a map that provides detailed drawings of the distribution system’s 

zones. Sometimes we call these quarter-sections. 

SEDIMENTATION BASIN: Where the thickest and greatest concentration of sludge will be found. 

Twice a year sedimentation tanks should be drained and cleaned if the sludge buildup interferes with 

the treatment process. 

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SEDIMENTATION: The process of suspended solid particles settling out (going to the bottom of the 

vessel) in water. 

SEDIMENT: Grains of soil, sand, gravel, or rock deposited by and generated by water movement. 

SENSOR: A float and cable system are commonly found instruments that may be used as a sensor to 

control the level of liquid in a tank or basin. 

SESSILE: Botany. attached by the base, or without any distinct projecting support, as a leaf issuing 

directly from the stem. Zoology. permanently attached; not freely moving. 

SETTLED SOLIDS: Solids that have been removed from the raw water by the coagulation and settling 

processes. 

SHAKER: A device used in mud containment systems that vibrates various sized screens as drilling 

fluid passes through it, thereby separating cuttings from drilling fluid and providing a good sampling 

location. 

SHOCK: Also known as superchlorination or break point chlorination. Ridding a water of organic waste 

through oxidization by the addition of significant quantities of a halogen. 

SHORT-CIRCUITING: Short Circuiting is a condition that occurs in tanks or basins when some of the 

water travels faster than the rest of the flowing water. This is usually undesirable since it may result in 

shorter contact, reaction or settling times in comparison with the presumed detention times. 

SHROUD: A baffle or piece of pipe installed over a pump to force water to pass the pumps motor. 

SIEVE ANALYSIS: The process of sifting soil or formation samples through a series of screens to 

determine percentages of particle sizes. 

SINGLE PHASE POWER: The type of power used for lighting systems, small motors, appliances, 

portable power tools and in homes. 

SINUSOID: A curve described by the equation y = a sin x, the ordinate being proportional to the sine of 

the abscissa. 

SINUSOIDAL: Mathematics. Of or pertaining to a sinusoid. Having a magnitude that varies as the sine 

of an independent variable: a sinusoidal current. 

SLUDGE BASINS: After cleaning sludge basins and before returning the tanks into service the tanks 

should be inspected, repaired if necessary, and disinfected. 

SLUDGE REDUCTION: Organic polymers are used to reduce the quantity of sludge. If a plant 

produces a large volume of sludge, the sludge could be dewatered, thickened, or conditioned to 

decrease the volume of sludge. Turbidity of source water, dosage, and type of coagulant used are the 

most important factors which determine the amount of sludge produced in a treatment of water. 

SLURRY: A mixture of crushed rock and water. 

SMALL WATER SYSTEM: 3,300 or fewer persons. 

SOC: Synthetic organic chemical. A common way for a synthetic organic chemical such as dioxin to 

be introduced to a surface water supply is from an industrial discharge, agricultural drainage, or a spill. 

SODA ASH: Chemical used to raise pH and total alkalinity (sodium carbonate) 

SODIUM BICARBONATE: Commonly used to increase alkalinity of water and stabilize pH. 

SODIUM BISULFATE: Chemical used to lower pH and total alkalinity (dry acid). 

SODIUM HYDROXIDE: Also known as caustic soda, a by-product chlorine generation and often used 

to raise pH. 

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SOIL MOISTURE: A relative consideration of the degree to which a soil is saturated. 

SOFTENING WATER: When the water has a low alkalinity it is advantageous to use soda ash instead 

of caustic soda for softening water. 

SOFTENING: The process that removes the ions which cause hardness in water. 

SOLAR DRYING BEDS OR LAGOONS: Are shallow, small-volume storage pond where sludge is 

concentrated and stored for an extended periods. 

SOLAR DRYING BEDS, CENTRIFUGES AND FILTER PRESSES: Are procedures used in the 

dewatering of sludge. 

SOLID, LIQUID AND VAPOR: 3 forms of matter. 

SOLDER: A fusible alloy used to join metallic parts. 

SOLID STEM (AUGER): An auger that is constructed of solid stem drill flights. 

SPADNS: The lab reagent called SPADNS solution is used in performing the Fluoride test. 

SPECIFIC CAPACITY (Sc): A measure of a well’s pumping performance in gallons per minute per foot 

of drawdown. 

SPIDER: A bearing or flange used in vertical turbine pumps to stabilize the drive shaft or shaft tube and 

seal column joints. 

SPIRAL FLANGE: A continuous blade that wraps spirally around auger flighting. 

SPIRIT OF HARTSHORN: A colorless, pungent, suffocating, aqueous solution of about 28.5 percent 

ammonia gas: used chiefly as a detergent, for removing stains and extracting certain vegetable coloring 

agents, and in the manufacture of ammonium salts. 

SPLIT SPOON: A sampling device that is driven into the earth and operated by a wire line for the 

retrieval of soil or formation samples. 

SPLIT FLOW CONTROL SYSTEM: This type of control system is to control the flow to each filter 

influent which is divided by a weir. 

SPRAY BOTTLE OF AMMONIA: An operator should use ammonia to test for a chlorine leak around a 

valve or pipe. You will see white smoke if there is a leak. 

SPRING PRESSURE: Is what maintains contact between the two surfaces of a mechanical seal. 

STABILE: Reference to formation, soil, or sediments of sufficient strength to remain in place under its 

own weight and existing pressures. 

STABILIZE: Actions taken to enhance borehole stability or vertical rotational when drilling. 

STABILIZER: The portion of a drill string used to stabilize rotation. 

STANDPIPE: A water tank that is taller than it is wide. Should not be found in low point. 

STERILIZED GLASSWARE: The only type of glassware that should be used in testing for coliform 

bacteria. 

STORAGE TANKS: Three types of water usage that determine the volume of a storage tank are fire 

suppression storage, equalization storage, and emergency storage. Equalization storage is the volume 

of water needed to supply the system for periods when demand exceeds supply. Generally, a water 

storage tank’s interior coating (paint) protects the interior about 3-5 years. 

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S.T.P.: Standard temperature and pressure standard temperature and pressure the temperature of 

0°C and pressure of 1 atmosphere, usually taken as the conditions when stating properties of gases. 

STRATIFIED: Layered. 

STUFFING BOX: That portion of the pump that houses the packing or mechanical seal. 

SUB: A small section of drill pipe used to connect larger sections. 

SUBMERSIBLE PUMP: A turbine pump that has the motor attached directly to it and therefore is 

operated while submerged. 

SULFATE: Will readily dissolve in water to form an anion. Sulfate is a substance that occurs naturally 

in drinking water. Health concerns regarding sulfate in drinking water have been raised because of 

reports that diarrhea may be associated with the ingestion of water containing high levels of sulfate. Of 

particular concern are groups within the general population that may be at greater risk from the laxative 

effects of sulfate when they experience an abrupt change from drinking water with low sulfate 

concentrations to drinking water with high sulfate concentrations. 

Sulfate in drinking water currently has a secondary maximum contaminant level (SMCL) of 250 

milligrams per liter (mg/L), based on aesthetic effects (i.e., taste and odor). This regulation is not a 

federally enforceable standard, but is provided as a guideline for States and public water systems. EPA 

estimates that about 3% of the public drinking water systems in the country may have sulfate levels of 

250 mg/L or greater. The Safe Drinking Water Act (SDWA), as amended in 1996, directs the U.S. 

Environmental Protection Agency (EPA) and the Centers for Disease Control and Prevention (CDC) to 

jointly conduct a study to establish a reliable dose-response relationship for the adverse human health 

effects from exposure to sulfate in drinking water, including the health effects that may be experienced 

by sensitive subpopulations (infants and travelers). SDWA specifies that the study be based on the best 

available peer-reviewed science and supporting studies, conducted in consultation with interested 

States, and completed in February 1999. 

SULFIDE: The term sulfide refers to several types of chemical compounds containing sulfur in its lowest 

oxidation number of -2. Formally, "sulfide" is the dianion, S2 - , which exists in strongly alkaline aqueous 

solutions formed from H2S or alkali metal salts such as Li2S, Na2S, and K2S. Sulfide is exceptionally 

basic and, with a pKa > 14, it does not exist in appreciable concentrations even in highly alkaline water, 

being undetectable at pH < ~15 (8 M NaOH). Instead, sulfide combines with electrons in hydrogen to 

form HS, which is variously called hydrogen sulfide ion, hydrosulfide ion, sulfhydryl ion, or bisulfide ion. 

At still lower pH's (

SURFACTANT: Surfactants reduce the surface tension of water by adsorbing at the liquid-gas 

interface. They also reduce the interfacial tension between oil and water by adsorbing at the liquid-liquid 

interface. Many surfactants can also assemble in the bulk solution into aggregates. Examples of such 

aggregates are vesicles and micelles. The concentration at which surfactants begin to form micelles is 

known as the critical micelle concentration or CMC. When micelles form in water, their tails form a core 

that can encapsulate an oil droplet, and their (ionic/polar) heads form an outer shell that maintains 

favorable contact with water. When surfactants assemble in oil, the aggregate is referred to as a 

reverse micelle. In a reverse micelle, the heads are in the core and the tails maintain favorable contact 

with oil. Surfactants are also often classified into four primary groups; anionic, cationic, non-ionic, and 

zwitterionic (dual charge). 

SUSCEPTIBILITY WAIVER: A waiver that is granted based upon the results of a vulnerability 

assessment. 

SURGE-BLOCK: A disc shaped device that fits tightly into a well and is moved up and down to agitate 

the water column in order to develop a well. 

SURGING: The process of purging a well rapidly for well development. 

SWAB: See Surge-block. 

SWING ARM: A large moveable arm on a bucket auger rig that pulls the bucket auger out away from 

the drilling rig for dumping. 

SYNCHRONY: Simultaneous occurrence; synchronism. 

TABLE DRIVE: A drilling rig that uses a rotating table within the platform to turn a kelly driven drill 

string. 

TABLE: The back portion of a drill rig where the drill pipe is inserted (or driven if a table drive), 

adjacent to or within the driller’s platform. 

TAPPING VALVE: The name of the valve that is specifically designed for connecting a new water main 

to an existing main that is under pressure. 

TARGET DEPTH: The proposed construction depth of a well prior to drilling. 

TASTE AND ODORS: The primary purpose to use potassium permanganate in water treatment is to 

control taste and odors. Anaerobic water undesirable for drinking water purposes because of color and 

odor problems are more likely to occur under these conditions. Taste and odor problems in the water 

may happen if sludge and other debris are allowed to accumulate in a water treatment plant. 

TCE, trichloroethylene: A solvent and degreaser used for many purposes; for example dry cleaning, it 

is a common groundwater contaminant. Trichloroethylene is a colorless liquid which is used as a 

solvent for cleaning metal parts. Drinking or breathing high levels of trichloroethylene may cause 

nervous system effects, liver and lung damage, abnormal heartbeat, coma, and possibly death. 

Trichloroethylene has been found in at least 852 of the 1,430 National Priorities List sites identified by 

the Environmental Protection Agency (EPA). 

TDS-TOTAL DISSOLVED SOLIDS: An expression for the combined content of all inorganic and 

organic substances contained in a liquid which are present in a molecular, ionized or micro-granular 

(colloidal sol) suspended form. Generally, the operational definition is that the solids (often abbreviated 

TDS) must be small enough to survive filtration through a sieve size of two micrometers. Total dissolved 

solids are normally only discussed for freshwater systems, since salinity comprises some of the ions 

constituting the definition of TDS. The principal application of TDS is in the study of water quality for 

streams, rivers and lakes, although TDS is generally considered not as a primary pollutant (e.g. it is not 

deemed to be associated with health effects), but it is rather used as an indication of aesthetic 

characteristics of drinking water and as an aggregate indicator of presence of a broad array of chemical 

contaminants. Ion exchange is an effective treatment process used to remove iron and manganese in a 

water supply. This process is ideal as long as the water does not contain a large amount of TDS. When 

determining the total dissolved solids, a sample should be filtered before being poured into an 

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evaporating dish and dried. Demineralization may be necessary in a treatment process if the water has 

a very high value Total Dissolved Solids. 

TELEMETERING: The use of a transmission line with remote signaling to monitor a pumping station or 

motors. Can be used to accomplish accurate and reliable remote monitoring and control over a long 


TEMPERATURE SAMPLE: This test should be performed immediately in the field, this is a grab 

sample. 

TELESCOPING KELLY: A kelly with successively smaller sized pipe within itself that drops out as a 

borehole is drilled. This permits that drilling may proceed without adding drill pipe. Normally found on 

bucket auger rigs. 

TELESCOPING: The successive decrease in borehole size with depth. 

THE RATE DECREASES: In general, when the temperature decreases, the chemical reaction rate 

decreases also. 

THICKENING, CONDITIONING AND DEWATERING: Common processes that are utilized to reduce 

the volume of sludge. 

TIME FOR TURBIDITY BREAKTHROUGH AND MAXIMUM HEADLOSS: Are the two factors which 

determine whether or not a change in filter media size should be made. 

TITRATION: A method of testing by adding a reagent of known strength to a water sample until a 

specific color change indicates the completion of the reaction. 

TITRIMETRIC: Chemistry. Using or obtained by titration. Titrimetrically, adverb. 

TOP DRIVE: A rotary type drill head that moves freely up and down the rigs mast while driving the drill 

string. 

TOROID: A surface generated by the revolution of any closed plane curve or contour about an axis 

lying in its plane. The solid enclosed by such a surface. 

TOTAL ALKALINITY: A measure of the acid-neutralizing capacity of water which indicates its buffering 

ability, i.e. measure of its resistance to a change in pH. Generally, the higher the total alkalinity, the 

greater the resistance to pH change. 

TOTAL COLIFORM: Total coliform, fecal coliform, and E. coli are all indicators of drinking water quality. 

The total coliform group is a large collection of different kinds of bacteria. Fecal coliforms are types of 

total coliform that mostly exist in feces. E. coli is a sub-group of fecal coliform. When a water sample is 

sent to a lab, it is tested for total coliform. If total coliform is present, the sample will also be tested for 

either fecal coliform or E. coli, depending on the lab testing method. 

TOTAL DISSOLVED SOLIDS (TDS): The accumulated total of all solids that might be dissolved in 

water. 

TOTAL DYNAMIC HEAD: The pressure (psi) or equivalent feet of water, required for a pump to lift 

water to its point of storage overcoming elevation head, friction loss, line pressure, drawdown and 

pumping lift. 

TRANSIENT, NON-COMMUNITY WATER SYSTEM: TNCWS A water system which provides water in 

a place such as a gas station or campground where people do not remain for long periods of time. 

These systems do not have to test or treat their water for contaminants which pose long-term health 

risks because fewer than 25 people drink the water over a long period. They still must test their water 

for microbes and several chemicals. A Transient Non-community Water System: Is not required to 

sample for VOC’s. 

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TREATED WATER: Disinfected and/or filtered water served to water system customers. It must meet 

or surpass all drinking water standards to be considered safe to drink. 

TRIHALOMETHANES (THM): Four separate compounds including chloroform, dichlorobromomethane, 

dibromochloromethane, and bromoform. The most common class of disinfection by-products created 

when chemical disinfectants react with organic matter in water during the disinfection process. See 

Disinfectant Byproducts. 

TRICONE BIT: A roller bit with three independent rolling bits with teeth or buttons that intermesh for 

efficient rock crushing and cutting. 

TUBE SETTLERS: This modification of the conventional process contains many metal tubes that are 

placed in the sedimentation basin, or clarifier. These tubes are approximately 1 inch deep and 36 

inches long, split-hexagonal shape and installed at an angle of 60 degrees or less. These tubes provide 

for a very large surface area upon which particles may settle as the water flows upward. The slope of 

the tubes facilitates gravity settling of the solids to the bottom of the basin, where they can be collected 

and removed. The large surface settling area also means that adequate clarification can be obtained 

with detention times of 15 minutes or less. As with conventional treatment, this sedimentation step is 

followed by filtration through mixed media. 

TUBERCLES: The creation of this condition is of the most concern regarding corrosive water effects on 

a water system. Tubercles are formed due to joining dissimilar metals, causing electro-chemical 

reactions. Like iron to copper pipe. We have all seen these little rust mounds inside cast iron pipe. 

TURBIDIMETER: Monitoring the filter effluent turbidity on a continuous basis with an in-line instrument 

is a recommended practice. Turbidimeter is best suited to perform this measurement. 

TURBIDITY: A measure of the cloudiness of water caused by suspended particles. 

TURBINE PUMP: A pump that utilizes rotating impellers on a shaft that generate centrifugal force for 

pumping water. 

UNCONFINED AQUIFER: An aquifer that exists under atmospheric pressure and is not confined. 

UNCONSOLIDATED: Sediment that is not cemented or is loosely arranged. 

UNDER-REAM: The process of reaming, from within the borehole, a section of an existing smaller 

borehole area. 

UNSATURATED ZONE: That portion of the subsurface, including the capillary fringe that is not 

saturated but may contain water in both vapor and liquid form. See also Vadose Zone. 

UNSTABLE: Sediment or other material that cannot exit without rapidly decomposing or collapsing in 

on itself. (ex. unconsolidated sediment) 

U.S. ENVIRONMENTAL PROTECTION AGENCY: In the United States, this agency responsible for 

setting drinking water standards and for ensuring their enforcement. This agency sets federal 

regulations which all state and local agencies must enforce. 

UNDER PRESSURE IN STEEL CONTAINERS: After chlorine gas is manufactured, it is primarily 

transported in steel containers. 

UNIT FILTER RUN VOLUME (UFRV): One of the most popular ways to compare filter runs. This 

technique is the best way to compare water treatment filter runs. 

VADOSE ZONE: A portion of the subsurface above the water table that is not saturated but contains 

water in both vapor and liquid form. The portion of the subsurface where water percolates through to 

the saturated zone. See also Unsaturated Zone. 

VANE: That portion of an impeller that throws the water toward the volute. 

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VARIABLE DISPLACEMENT PUMP: A pump that will produce different volumes of water dependent 

on the pressure head against it. 

VELOCITY HEAD: The vertical distance a liquid must fall to acquire the velocity with which it flows 

through the piping system. For a given quantity of flow, the velocity head will vary indirectly as the pipe 

diameter varies. 

VENTURI: If water flows through a pipeline at a high velocity, the pressure in the pipeline is reduced. 

Velocities can be increased to a point that a partial vacuum is created. 

VERTICAL TURBINE: A type of variable displacement pump in which the motor or drive head is 

mounted on the wellhead and rotates a drive shaft connected to the pump impellers. 

VIRION: A complete viral particle, consisting of RNA or DNA surrounded by a protein shell and 

constituting the infective form of a virus. 

VIRUSES: Very small disease-causing microorganisms that are too small to be seen even with 

microscopes. Viruses cannot multiply or produce disease outside of a living cell. 

VITRIFICATION: Vitrification is a process of converting a material into a glass-like amorphous solid that 

is free from any crystalline structure, either by the quick removal or addition of heat, or by mixing with an 

additive. Solidification of a vitreous solid occurs at the glass transition temperature (which is lower than 

melting temperature, Tm, due to supercooling). When the starting material is solid, vitrification usually 

involves heating the substances to very high temperatures. Many ceramics are produced in such a 

manner. Vitrification may also occur naturally when lightning strikes sand, where the extreme and 

immediate heat can create hollow, branching rootlike structures of glass, called fulgurite. When applied 

to whiteware ceramics, vitreous means the material has an extremely low permeability to liquids, often 

but not always water, when determined by a specified test regime. The microstructure of whiteware 

ceramics frequently contain both amorphous and crystalline phases. 

VOC WAIVER: The longest term VOC waiver that a public water system using groundwater could 

receive is 9 years. 

VOLATILE ORGANIC COMPOUNDS: (VOCs) Solvents used as degreasers or cleaning agents. 

Improper disposal of VOCs can lead to contamination of natural waters. VOCs tend to evaporate very 

easily. This characteristic gives VOCs very distinct chemical odors like gasoline, kerosene, lighter fluid, 

or dry cleaning fluid. Some VOCs are suspected cancer-causing agents. Volatile organic compounds 

(VOCs) are organic chemical compounds that have high enough vapor pressures under normal 

conditions to significantly vaporize and enter the atmosphere. A wide range of carbon-based molecules, 

such as aldehydes, ketones, and other light hydrocarbons are VOCs. The term often is used in a legal 

or regulatory context and in such cases the precise definition is a matter of law. These definitions can 

be contradictory and may contain "loopholes"; e.g. exceptions, exemptions, and exclusions. The United 

States Environmental Protection Agency defines a VOC as any organic compound that participates in a 

photoreaction; others believe this definition is very broad and vague as organics that are not volatile in 

the sense that they vaporize under normal conditions can be considered volatile by this EPA definition. 

The term may refer both to well characterized organic compounds and to mixtures of variable 

composition. 

VOID: An opening, gap, or space within rock or sedimentary formations formed at the time of origin or 

deposition. 

VOLTAGE: Voltage (sometimes also called electric or electrical tension) is the difference of electrical 

potential between two points of an electrical or electronic circuit, expressed in volts. It measures the 

potential energy of an electric field to cause an electric current in an electrical conductor. Depending on 

the difference of electrical potential it is called extra low voltage, low voltage, high voltage or extra high 

voltage. Specifically Voltage is equal to energy per unit charge. 

VOLUTE: The spiral-shaped casing surrounding a pump impeller that collects the liquid discharge by 

the impeller. 

VORTEX: The helical swirling of water moving towards a pump. 

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VIRUSES: Are very small disease-causing microorganisms that are too small to be seen even with 

microscopes. Viruses cannot multiply or produce disease outside of a living cell. 

VOLATILE ORGANIC COMPOUNDS: (VOCs) Solvents used as degreasers or cleaning agents. 

Improper disposal of VOCs can lead to contamination of natural waters. VOCs tend to evaporate very 

easily. This characteristic gives VOCs very distinct chemical odors like gasoline, kerosene, lighter fluid, 

or dry cleaning fluid. Some VOCs are suspected cancer-causing agents. 

VULNERABILITY ASSESSMENT: An evaluation of drinking water source quality and its vulnerability to 

contamination by pathogens and toxic chemicals. 

WAIVERS: Monitoring waivers for nitrate and nitrite are prohibited. 

WASHOUT: The rapid erosion of aquifer material from the borehole walls while a well is being drilled, 

which often results in a loss of circulation. 

WATER COURSE: An opening within a cable tool drill string that allows fluid to flow in and out of the 

drill string thereby minimizing friction loss to the slurry. 

WATER HAMMER: A surge in a pipeline resulting from the rapid increase or decrease in water flow. 

Water hammer exerts tremendous force on a system and can be highly destructive. 

WATER PURVEYOR: The individuals or organization responsible to help provide, supply, and furnish 

quality water to a community. 

WATER QUALITY: The 4 broad categories of water quality are: Physical, chemical, biological, 

radiological. Pathogens are disease causing organisms such as bacteria and viruses. A positive 

bacteriological sample indicates the presence of bacteriological contamination. Source water monitoring 

for lead and copper be performed when a public water system exceeds an action level for lead of 

copper. 

WATER QUALITY CRITERIA: Comprised of both numeric and narrative criteria. Numeric criteria are 

scientifically derived ambient concentrations developed by EPA or States for various pollutants of 

concern to protect human health and aquatic life. Narrative criteria are statements that describe the 

desired water quality goal. 

WATER QUALITY STANDARD: A statute or regulation that consists of the beneficial designated use or 

uses of a waterbody, the numeric and narrative water quality criteria that are necessary to protect the 

use or uses of that particular waterbody, and an antidegradation statement. 

WATER TABLE: The measured water level surface of an unconfined aquifer. 

WATER VAPOR: A characteristic that is unique to water vapor in the atmosphere is that water does 

not contain any salts. 

WATERBORNE DISEASE: A disease, caused by a virus, bacterium, protozoan, or other 

microorganism, capable of being transmitted by water (e.g., typhoid fever, cholera, amoebic dysentery, 

gastroenteritis). 

WATERSHED: An area that drains all of its water to a particular water course or body of water. The 

land area from which water drains into a stream, river, or reservoir. 

WEATHERED: The existence of rock or formation in a chemically or physically broken down or 

decomposed state. Weathered material is in an unstable state. 

WELL ABANDONMENT: The process of sealing a well by approved means. The filling of a well to the 

surface with cement grout. 

WELL HEAD: The upper portion of the well that is constructed on the land surface, including the well 

manifold. Also a term used to refer to the area near the well that is subject to wellhead protection. 

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WELL HEAD PROTECTION: Programs designed to maintain the quality of groundwater used as public 

drinking water sources, by managing the land uses around the well field. A government program that 

encourages the limitation and elimination of activities, near and within a wells recharge area, which 

present a potential risk to the wells water supply. 

WELL MANIFOLD: The piping, valves, and metering equipment used to connect the well to the 

distribution system, installed on the wellhead. 

WELL SCREEN: A section of well casing that contains openings which permit water to enter the well 

but limit or prevent sediment from entering the well while pumping. 

WELL SEAL: The watertight cap or seal installed within and between the well casing and pumping 

equipment. The metal or plastic plug or seal, which the pumping column rests on the top of casing. 

WHOLE EFFLUENT TOXICITY: The total toxic effect of an effluent measured directly with a toxicity 

test. 

YIELD: The volume of water measured in flow rates that are produced from the well. 

ZONE OF AERATION: See Saturated Zone or Vadose Zone. 

ZONE OF SATURATION: See Saturated Zone. 

Top- Pre-sedimentation basin 

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Common Water Treatment and Distribution Chemicals 

Chemical Name Common Name Chemical Formula 

Aluminum hydroxide Al(OH)3 

Aluminum sulfate Alum, liquid AL2(SO4)3 . 14(H2O) 

Ammonia NH3 

Ammonium NH4 

Bentonitic clay Bentonite 

Calcium bicarbonate Ca(HCO3)2 

Calcium carbonate Limestone CaCO3 

Calcium chloride CaCl2 

Calcium Hypochlorite HTH Ca(OCl)2 . 4H2O 

Calcium hydroxide Slaked Lime Ca(OH)2 

Calcium oxide Unslaked (Quicklime) CaO 

Calcium sulfate Gypsum CaSO4 

Carbon Activated Carbon C 

Carbon dioxide CO2 

Carbonic acid H2CO3 

Chlorine gas Cl2 

Chlorine Dioxide ClO2 

Copper sulfate Blue vitriol CuSO4 . 5H2O 

Dichloramine NHCl2 

Ferric chloride Iron chloride FeCl3 

Ferric hydroxide Fe(OH)3 

Ferric sulfate Iron sulfate Fe2(SO4)3 

Ferrous bicarbonate Fe(HCO3)2 

Ferrous hydroxide Fe(OH)3 

Ferrous sulfate Copperas FeSO4.7H20 

Hydrofluorsilicic acid H2SiF6 

Hydrochloric acid Muriatic acid HCl 

Hydrogen sulfide H2S 

Hypochlorus acid HOCL 

Magnesium bicarbonate Mg(HCO3)2 

Magnesium carbonate MgCO3 

Magnesium chloride MgCl2 

Magnesium hydroxide Mg(OH)2 

Magnesium dioxide MgO2 

Manganous bicarbonate Mn(HCO3)2 

Manganous sulfate MnSO4 

Monochloramine NH2Cl 

Potassium bicarbonate KHCO3 

Potassium permanganate KMnO4 

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Chemical Name Common Name Chemical Formula 

Sodium carbonate Soda ash Na2CO3 

Sodium chloride Salt NaCl 

Sodium chlorite NaClO2 

Sodium fluoride NaF 

Sodium fluorsilicate Na2SiF6 

Sodium hydroxide Lye NaOH 

Sodium hypochlorite NaOCl 

Sodium Metaphosphate Hexametaphosphate NaPO3 

Sodium phosphate Disodium phosphate Na3PO4 

Sodium sulfate Na2SO4 

Sulfuric acid H2SO4 

Fluoride. Many communities add fluoride to their drinking water to promote dental 

health. Each community makes its own decision about whether or not to add fluoride. 

The EPA has set an enforceable drinking water standard for fluoride of 4 mg/L (some 

people who drink water containing fluoride in excess of this level over many years could 

develop bone disease, including pain and tenderness of the bones). The EPA has also 

set a secondary fluoride standard of 2 mg/L to protect against dental fluorosis. 

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Microorganism Appendix 

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This section will give a close-up and short explanation of the major 

microorganisms found in water and in wastewater. 

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Protozoa 

Protozoa are around 10–50 micrometer, but can grow up to 1 mm and can easily be 

seen under a microscope. Protozoa exist throughout aqueous environments and soil. 

Protozoa occupy a range of trophic levels. As predators, they prey upon unicellular or 

filamentous algae, bacteria, and microfungi. 

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Protozoa play a role both as herbivores and as consumers in the decomposer link of the 

food chain. Protozoa also play a vital role in controlling bacteria populations and 

biomass. As components of the micro- and meiofauna, protozoa are an important food 

source for microinvertebrates. Thus, the ecological role of protozoa in the transfer of 

bacterial and algal production to successive trophic levels is important. Protozoa such as 

the malaria parasites (Plasmodium spp.), trypanosomes and leishmania are also 

important as parasites and symbionts of multicellular animals. 

Most protozoa exist in 5 stages of life which are in the form of trophozoites and cysts. As 

cysts, protozoa can survive harsh conditions, such as exposure to extreme temperatures 

and harmful chemicals, or long periods without access to nutrients, water, or oxygen for 

a period of time. Being a cyst enables parasitic species to survive outside of the host, 

and allows their transmission from one host to another. When protozoa are in the form of 

trophozoites (Greek, tropho=to nourish), they actively feed and grow. The process by 

which the protozoa takes its cyst form is called encystation, while the process of 

transforming back into trophozoite is called excystation. 

Protozoa can reproduce by binary fission or multiple fission. Some protozoa reproduce 

sexually, some asexually, and some both (e.g. Coccidia). An individual protozoan is 

hermaphroditic. 

Classification 

Protozoa were commonly grouped in the kingdom of Protista together with the plant-like 

algae and fungus-like water molds and slime molds. In the 21st-century systematics, 

protozoans, along with ciliates, mastigophorans, and apicomplexans, are arranged as 

animal-like protists. However, protozoans are neither Animalia nor Metazoa (with the 

possible exception of the enigmatic, moldy Myxozoa). 

Sub-groups 

Protozoa have traditionally been divided on the basis of their means of locomotion, 

although this is no longer believed to represent genuine relationships: 

* Flagellates (e.g. Giardia lambia) 

* Amoeboids (e.g. Entamoeba histolytica) 

* Sporozoans (e.g. Plasmodium knowlesi) 

* Apicomplexa 

* Myxozoa 

* Microsporidia 

* Ciliates (e.g. Balantidium coli) 

There are many ways that infectious diseases can spread. Pathogens usually have 

specific routes by which they are transmitted, and these routes may depend on the type 

of cells and tissue that a particular agent targets. For example, because cold viruses 

infect the respiratory tract, they are dispersed into the air via coughing and sneezing. 

Once in the air, the viruses can infect another person who is unlucky enough to inhale 

air containing the virus particles. 

Agents vary greatly in their stability in the environment. Some viruses may survive for 

only a few minutes outside of a host, while some spore-forming bacteria are extremely 

durable and may survive in a dormant state for a decade or more. 

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Protozoa Section 

The diverse assemblage of organisms that carry out all of their life functions within the 

confines of a single, complex eukaryotic cell are called protozoa. 

Paramecium, Euglena, and Amoeba are well-known examples of these major groups of 

organisms. Some protozoa are more closely related to animals, others to plants, and still 

others are relatively unique. Although it is not appropriate to group them together into a 

single taxonomic category, the research tools used to study any unicellular organism are 

usually the same, and the field of protozoology has been created to carry out this 

research. The unicellular photosynthetic protozoa are sometimes also called algae and 

are addressed elsewhere. This report considers the status of our knowledge of 

heterotrophic protozoa (protozoa that cannot produce their own food). 

Free-living Protozoa 

Protozoans are found in all moist habitats within the United States, but we know little 

about their specific geographic distribution. Because of their small size, production of 

resistant cysts, and ease of distribution from one place to another, many species appear 

to be cosmopolitan and may be collected in similar microhabitats worldwide (Cairns and 

Ruthven 1972). Other species may have relatively narrow limits to their distribution. 

Marine ciliates inhabit interstices of sediment and beach sands, surfaces, deep sea and 

cold Antarctic environments, planktonic habitats, and the algal mats and detritus of 

estuaries and wetlands. 

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Amoeba proteus, pseudopods slowly engulf the small desmid Staurastrum. 

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Amoebas 

Amoebas (Phylum Rhizopoda) are unicellular protists that are able to change their 

shape constantly. Each species has its own distinct repertoire of shapes. 

How does an amoeba locomote? 

Amoebas locomote by way of cytoplasmic movement. (cytoplasm is the cell content 

around the nucleus of the cell) The amoeba forms pseudopods (false feet) with which 

they 'flow' over a surface. The cytoplasma not only flows, it also changes from a fluid into 

a solid state. 

These pseudopods are also used to capture prey, they simply engulf the food. They can 

detect the kind of prey and use different 'engulfing tactics'. 

The image from the last page shows several cell organelles. Left from the center we can 

see aspherical water expelling vesicle and just right of it, the single nucleus of this 

species can be seen. Other species may have many nuclei. The cell is full of brown food 

vacuoles and also contains small crystals. 

Protozoa Information 

Our actual knowledge of salinity, temperature, and oxygen requirements of marine 

protozoa is poor (although some groups, such as the foraminifera, are better studied 

than others), and even the broadest outlines of their biogeographic ranges are usually a 

mystery. In general, freshwater protozoan communities are similar to marine 

communities except the specialized interstitial fauna of the sand is largely missing. In 

freshwater habitats, the foraminifera and radiolaria common in marine environments are 

absent or low in numbers while testate amoebae exist in greater numbers. Relative 

abundance of species in the marine versus freshwater habitat is unknown. 

Soil-dwelling protozoa have been documented from almost every type of soil and in 

every kind of environment, from the peat-rich soil of bogs to the dry sands of deserts. In 

general, protozoa are found in greatest abundance near the soil surface, especially in 

the upper 15 cm (6 in), but occasional isolates can be obtained at depths of a meter 

(yard) or more. 

Protozoa do not constitute a major part of soil biomass, but in some highly productive 

regions such as forest litter, the protozoa are a significant food source for the 

microinvertebrates, with a biomass that may reach 20 g/m2 of soil surface area there. 

Environmental Quality Indicators 

Polluted waters often have a rich and characteristic protozoan fauna. The relative 

abundance and diversity of protozoa are used as indicators of organic and toxic pollution 

(Cairns et al. 1972; Foissner 1987; Niederlehner et al. 1990; Curds 1992). Bick (1972), 

for example, provided a guide to ciliates that are useful as indicators of environmental 

quality of European freshwater systems, along with their ecological distribution with 

respect to parameters such as amount of organic material and oxygen levels. 

Foissner (1988) clarified the taxonomy of European ciliates as part of a system for 

classifying the state of aquatic habitats according to their faunas. 

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Symbiotic Protozoa 

Parasites 

Protozoa are infamous for their role in causing disease, and parasitic species are among 

the best-known protozoa. Nevertheless, our knowledge has large gaps, especially of 

normally free-living protozoa that may become pathogenic in immunocompromised 

individuals. For example, microsporidia comprise a unique group of obligate, intracellular 

parasitic protozoa. Microsporidia are amazingly diverse organisms with more than 700 

species and 80 genera that are capable of infecting a variety of plant, animal, and even 

other protist hosts. 

They are found worldwide and have the ability to thrive in many ecological conditions. 

Until the past few years, their ubiquity did not cause a threat to human health, and few 

systematists worked to describe and classify the species. Since 1985, however, 

physicians have documented an unusual rise in worldwide infections in AIDS patients 

caused by four different genera of microsporidia (Encephalitozoon, Nosema, 

Pleistophora, and Enterocytozoon). According to the Centers for Disease Control in the 

United States, difficulties in identifying microsporidian species are impeding diagnosis 

and effective treatment of AIDS patients. 

Protozoan Reservoirs of Disease 

The presence of bacteria in the cytoplasm of protozoa is well known, whereas that of 

viruses is less frequently reported. Most of these reports simply record the presence of 

bacteria or viruses and assume some sort of symbiotic relationship between them and 

the protozoa. Recently, however, certain human pathogens were shown to not only 

survive but also to multiply in the cytoplasm of free-living, nonpathogenic protozoa. 

Indeed, it is now believed that protozoa are the natural habitat for certain pathogenic 

bacteria. To date, the main focus of attention has been on the bacterium Legionella 

pneumophila, the causative organism of Legionnaires' disease; these bacteria live and 

reproduce in the cytoplasm of some free-living amoebae (Curds 1992). More on this 

subject in the following pages. 

Symbionts 

Some protozoa are harmless or even beneficial symbionts. A bewildering array of 

ciliates, for example, inhabit the rumen and reticulum of ruminates and the cecum and 

colon of equids. Little is known about the relationship of the ciliates to their host, but a 

few may aid the animal in digesting cellulose. 

Data on Protozoa 

While our knowledge of recent and fossil foraminifera in the U.S. coastal waterways is 

systematically growing, other free-living protozoa are poorly known. There are some 

regional guides and, while some are excellent, many are limited in scope, vague on 

specifics, or difficult to use. Largely because of these problems, most ecologists who 

include protozoa in their studies of aquatic habitats do not identify them, even if they do 

count and measure them for biomass estimates (Taylor and Sanders 1991). 

Parasitic protozoa of humans, domestic animals, and wildlife are better known although 

no attempt has been made to compile this information into a single source. Large gaps 

in our knowledge exist, especially for haemogregarines, microsporidians, and 

myxosporidians (see Kreier and Baker 1987). 

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Museum Specimens 

For many plant and animal taxa, museums represent a massive information resource. 

This is not true for protozoa. In the United States, only the National Natural History 

Museum (Smithsonian Institution) has a reference collection preserved on microscope 

slides, but it does not have a protozoologist curator and cannot provide species' 

identification or verification services. The American Type Culture Collection has some 

protozoa in culture, but its collection includes relatively few kinds of protozoa. 

Ecological Role of Protozoa 

Although protozoa are frequently overlooked, they play an important role in many 

communities where they occupy a range of trophic levels. As predators upon unicellular 

or filamentous algae, bacteria, and microfungi, protozoa play a role both as herbivores 

and as consumers in the decomposer link of the food chain. As components of the 

micro- and meiofauna, protozoa are an important food source for microinvertebrates. 

Thus, the ecological role of protozoa in the transfer of bacterial and algal production to 

successive trophic levels is important. 

Factors Affecting Growth and Distribution 

Most free-living protozoa reproduce by cell division (exchange of genetic material is a 

separate process and is not involved in reproduction in protozoa). The relative 

importance for population growth of biotic versus chemical-physical components of the 

environment is difficult to ascertain from the existing survey data. Protozoa are found 

living actively in nutrient-poor to organically rich waters and in fresh water varying 

between 0°C (32°F) and 50°C (122°F). Nonetheless, it appears that rates of population 

growth increase when food is not constrained and temperature is increased (Lee and 

Fenchel 1972; Fenchel 1974; Montagnes et al. 1988). 

Comparisons of oxygen consumption in various taxonomic groups show wide variation 

(Laybourn and Finlay 1976), with some aerobic forms able to function at extremely low 

oxygen tensions and to thereby avoid competition and predation. 

Many parasitic and a few free-living species are obligatory anaerobes (grow without 

atmospheric oxygen). Of the free-living forms, the best known are the plagiopylid ciliates 

that live in the anaerobic sulfide-rich sediments of marine wetlands (Fenchel et al. 1977). 

The importance of plagiopylids in recycling nutrients to aerobic zones of wetlands is 

potentially great. 

Because of the small size of protozoa, their short generation time, and (for some 

species) ease of maintaining them in the laboratory, ecologists have used protozoan 

populations and communities to investigate competition and predation. 

The result has been an extensive literature on a few species studied primarily under 

laboratory conditions. Few studies have been extended to natural habitats with the result 

that we know relatively little about most protozoa and their roles in natural communities. 

Intraspecific competition for common resources often results in cannibalism, sometimes 

with dramatic changes in morphology of the cannibals (Giese 1973). Field studies of 

interspecific competition are few and most evidence for such species interactions is 

indirect (Cairns and Yongue 1977). 

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Contractile Vacuoles 

Many protozoa have contractile vacuoles, which collect and expel excess water, and 

extrusomes, which expel material used to deflect predators or capture prey. In 

multicellular organisms, hormones are often produced in vesicles. In higher plants, most 

of a cell's volume is taken up by a central vacuole or tonoplast, which maintains its 

osmotic pressure. Many eukaryotes have slender motile projections, usually called 

flagella when long and cilia when short. These are variously involved in movement, 

feeding, and sensation. These are entirely distinct from prokaryotic flagella. They are 

supported by a bundle of microtubules arising from a basal body, also called a 

kinetosome or centriole, characteristically arranged as nine doublets surrounding two 

singlets. Flagella also may have hairs or mastigonemes, scales, connecting membranes, 

and internal rods. Their interior is continuous with the cell's cytoplasm. 

Centrioles 

Centrioles are often present even in cells and groups that do not have flagella. They 

generally occur in groups of one or two, called kinetids that give rise to various 

microtubular roots. These form a primary component of the cytoskeletal structure, and 

are often assembled over the course of several cell divisions, with one flagellum retained 

from the parent and the other derived from it. Centrioles may also be associated in the 

formation of a spindle during nuclear division. Some protists have various other 

microtubule-supported organelles. These include the radiolaria and heliozoa, which 

produce axopodia used in flotation or to capture prey, and the haptophytes, which have 

a peculiar flagellum-like organelle called the haptonema. 

Figure 1. A diagram of Paramecium sp. with major organelles indicated. 

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Contractile Vacuoles 

Figure 2. The contractile vacuole when full (top) and after contraction (bottom). 

Paramecium 

Members of the genus Paramecium are single-celled, freshwater organisms in the 

kingdom Protista. They exist in an environment in which the osmotic concentration in 

their external environment is much lower than that in their cytoplasm. More specifically, 

the habitat in which they live is hypotonic to their cytoplasm. As a result of this, 

Paramecium is subjected to a continuous influx of water, as water diffuses inward to a 

region of higher osmotic concentration. 

If Paramecium is to maintain homeostasis, water must be continually pumped out of the 

cell (against the osmotic gradient) at the same rate at which it moves in. This process, 

known as osmoregulation, is carried out by two organelles in Paramecium known as 

contractile vacuoles (Figures 1 and 2). 

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Coliform Bacteria on a Petri Dish. Bottom photo, SimPlate for HPC counts. 

IDEXX’s SimPlate for HPC method is used for the quantification of heterotrophic plate 

count (HPC) in water. It is based on the Multiple Enzyme Technology which detects 

viable bacteria in water by testing for the presence of key enzymes known to be present 

in these little organisms. This technique uses enzyme substrates that produce a blue 

fluorescence when metabolized by waterborne bacteria. The sample and media are 

added to a SimPlate Plate, incubated and then examined for fluorescing wells. The 

number of wells corresponds to a Most Probable Number (MPN) of total bacteria in the 

original sample. The MPN values generated by the SimPlate for HPC method correlate 

with the Pour Plate method using the Total Plate Count Agar incubated at 35 o C for 48 

hours as described in Standard Methods for the Examination of Water and Wastewater, 

19 th Edition. 

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Protozoan Diseases 

Protozoan pathogens are larger than bacteria and viruses, but still microscopic. They 

invade and inhabit the gastrointestinal tract. Some parasites enter the environment in a 

dormant form, with a protective cell wall called a “cyst.” The cyst can survive in the 

environment for long periods of time and be extremely resistant to conventional 

disinfectants such as chlorine. Effective filtration treatment is therefore critical to 

removing these organisms from water sources. 

Giardiasis 

Giardiasis is a commonly reported protozoan-caused disease. It has also been referred 

to as “backpacker’s disease” and “beaver fever” because of the many cases reported 

among hikers and others who consume untreated surface water. Symptoms include 

chronic diarrhea, abdominal cramps, bloating, frequent loose and pale greasy stools, 

fatigue and weight loss. The incubation period is 5-25 days or longer, with an average of 

7-10 days. Many infections are asymptomatic (no symptoms). Giardiasis occurs 

worldwide. Waterborne outbreaks in the United States occur most often in communities 

receiving their drinking water from streams or rivers without adequate disinfection or a 

filtration system. The organism, Giardia lamblia, has been responsible for more 

community-wide outbreaks of disease in the U.S. than any other pathogen. Drugs are 

available for treatment but are not 100% effective. 

Cryptosporidiosis 

Cryptosporidiosis is an example of a protozoan disease that is common worldwide, but 

was only recently recognized as causing human disease. The major symptom in humans 

is diarrhea, which may be profuse and watery. The diarrhea is associated with cramping 

abdominal pain. General malaise, fever, anorexia, nausea, and vomiting occur less 

often. Symptoms usually come and go, and end in fewer than 30 days in most cases. 

The incubation period is 1-12 days, with an average of about seven days. 

Cryptosporidium organisms have been identified in human fecal specimens from more 

than 50 countries on six continents. The mode of transmission is fecal-oral, either by 

person-to-person or animal-to-person. There is no specific treatment for 

Cryptosporidium infections. 

All of these diseases, with the exception of hepatitis A, have one symptom in common: 

diarrhea. They also have the same mode of transmission, fecal-oral, whether through 

person-to-person or animal-to-person contact, and the same routes of transmission, 

being either foodborne or waterborne. Although most pathogens cause mild, self-limiting 

disease, on occasion, they can cause serious, even life threatening illness. Particularly 

vulnerable are persons with weak immune systems such as those with HIV infections or 

cancer. By understanding the nature of waterborne diseases, the importance of properly 

constructed, operated and maintained public water systems becomes obvious. While 

water treatment cannot achieve sterile water (no microorganisms), the goal of treatment 

must clearly be to produce drinking water that is as pathogen-free as possible at all 

times. For those who operate water systems with inadequate source protection or 

treatment facilities, the potential risk of a waterborne disease outbreak is real. For those 

operating systems that currently provide adequate source protection and treatment, 

operating and maintaining the system at a high level on a continuing basis is critical to 

prevent disease. 

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Giardia Lamblia 

Giardia lamblia (synonymous with Lamblia intestinalis and Giardia duodenalis) is a 

flagellated protozoan parasite that colonizes and reproduces in the small intestine, 

causing giardiasis. The giardia parasite attaches to the epithelium by a ventral adhesive 

disc, and reproduces via binary fission. Giardiasis does not spread via the bloodstream, 

nor does it spread to other parts of the gastro-intestinal tract, but remains confined to the 

lumen of the small intestine. Giardia trophozoites absorb their nutrients from the lumen 

of the small intestine, and are anaerobes. 

Giardia infection can occur through ingestion of dormant cysts in contaminated water, or 

by the fecal-oral route (through poor hygiene practices). The Giardia cyst can survive for 

weeks to months in cold water and therefore can be present in contaminated wells and 

water systems, and even clean-looking mountain streams, as well as city reservoirs, as 

the Giardia cysts are resistant to conventional water treatment methods, such as 

chlorination and ozonolysis. Zoonotic transmission is also possible, and therefore 

Giardia infection is a concern for people camping in the wilderness or swimming in 

contaminated streams or lakes, especially the artificial lakes formed by beaver dams 

(hence the popular name for giardiasis, "Beaver Fever"). As well as water-borne 

sources, fecal-oral transmission can also occur, for example in day care centers, where 

children may have poorer hygiene practices. 

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Those who work with children are also at risk of being infected, as are family members 

of infected individuals. Not all Giardia infections are symptomatic, so some people can 

unknowingly serve as carriers of the parasite. 

The life cycle begins with a non-infective cyst being excreted with feces of an infected 

individual. Once out in the environment, the cyst becomes infective. A distinguishing 

characteristic of the cyst is 4 nuclei and a retracted cytoplasm. Once ingested by a host, 

the trophozoite emerges to an active state of feeding and motility. After the feeding 

stage, the trophozoite undergoes asexual replication through longitudinal binary fission. 

The resulting trophozoites and cysts then pass through the digestive system in the 

feces. While the trophozoites may be found in the feces, only the cysts are capable of 

surviving outside of the host. 

Distinguishing features of the trophozoites are large karyosomes and lack of peripheral 

chromatin, giving the two nuclei a halo appearance. Cysts are distinguished by a 

retracted cytoplasm. This protozoa lacks mitochondria, although the discovery of the 

presence of mitochodrial remnant organelles in one recent study "indicate that Giardia is 

not primitively amitochondrial and that it has retained a functional organelle derived from 

the original mitochondrial endosymbiont" 

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Cryptosporidium is a protozoan pathogen of the Phylum Apicomplexa and causes a 

diarrheal illness called cryptosporidiosis. Other apicomplexan pathogens include the 

malaria parasite Plasmodium, and Toxoplasma, the causative agent of toxoplasmosis. 

Unlike Plasmodium, which transmits via a mosquito vector, Cryptosporidium does not 

utilize an insect vector and is capable of completing its life cycle within a single host, 

resulting in cyst stages which are excreted in feces and are capable of transmission to a 

new host. 

A number of species of Cryptosporidium infect mammals. In humans, the main causes of 

disease are C. parvum and C. hominis (previously C. parvum genotype 1). C. canis, C. 

felis, C. meleagridis, and C. muris can also cause disease in humans. In recent years, 

cryptosporidiosis has plagued many commercial Leopard gecko breeders. Several 

species of the Cryptosporidium family (C. serpentes and others) are involved, and 

outside of geckos it has been found in monitor lizards, iguanas, tortoises as well as 

several snake species. 

Cryptosporidiosis is typically an acute short-term infection but can become severe and 

non-resolving in children and immunocompromised individuals. The parasite is 

transmitted by environmentally hardy cysts (oocysts) that, once ingested, excyst in the 

small intestine and result in an infection of intestinal epithelial tissue. 

The genome of Cryptosporidium parvum was sequenced in 2004 and was found to be 

unusual amongst Eukaryotes in that the mitochondria seem not to contain DNA. A 

closely-related species, C. hominis, also has its genome sequence available. 

CryptoDB.org is a NIH-funded database that provides access to the Cryptosporidium 

genomics data sets. 

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When C. parvum was first identified as a human pathogen, diagnosis was made by a 

biopsy of intestinal tissue (Keusch, et al., 1995). However, this method of testing can 

give false negatives due the "patchy" nature of the intestinal parasitic infection (Flanigan 

and Soave, 1993). Staining methods were then developed to detect and identify the 

oocysts directly from stool samples. The modified acid-fast stain is traditionally used to 

most reliably and specifically detect the presence of cryptosporidial oocysts. 

There have been six major outbreaks of cryptosporidiosis in the United States as a result 

of contamination of drinking water (Juranek, 1995). One major outbreak in Milwaukee in 

1993 affected over 400,000 persons. Outbreaks such as these usually result from 

drinking water taken from surface water sources such as lakes and rivers (Juranek, 

1995). Swimming pools and water park wave pools have also been associated with 

outbreaks of cryptosporidiosis. Also, untreated groundwater or well water public drinking 

water supplies can be sources of contamination. 

The highly environmentally resistant cyst of C. parvum allows the pathogen to survive 

various drinking water filtrations and chemical treatments such as chlorination. Although 

municipal drinking water utilities may meet federal standards for safety and quality of 

drinking water, complete protection from cryptosporidial infection is not guaranteed. In 

fact, all waterborne outbreaks of cryptosporidiosis have occurred in communities where 

the local utilities met all state and federal drinking water standards (Juranek, 1995). 

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Entamoeba histolytica 

Entamoeba histolytica, another water-borne pathogen, can cause diarrhea or a more 

serious invasive liver abscess. When in contact with human cells, these amoebae are 

cytotoxic. There is a rapid influx of calcium into the contacted cell, it quickly stops all 

membrane movement save for some surface blebbing. Internal organization is disrupted, 

organelles lyse, and the cell dies. The ameba may eat the dead cell or just absorb 

nutrients released from the cell. 

On average, about one in 10 people who are infected with E. histolytica becomes sick 

from the infection. The symptoms often are quite mild and can include loose stools, 

stomach pain, and stomach cramping. Amebic dysentery is a severe form of amebiasis 

associated with stomach pain, bloody stools, and fever. Rarely, E. histolytica invades the 

liver and forms an abscess. Even less commonly, it spreads to other parts of the body, 

such as the lungs or brain. 

Scientific classification 

Domain: Eukaryota 

Phylum: Amoebozoa 

Class: Archamoebae 

Genus: Entamoeba 

Species: E. histolytica 

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Mitochondria 

The bacterial cell is surrounded by a lipid membrane, or cell membrane, which encloses 

the contents of the cell and acts as a barrier to hold nutrients, proteins and other 

essential components of the cytoplasm within the cell. As they are prokaryotes, bacteria 

do not tend to have membrane-bound organelles in their cytoplasm and thus contain few 

large intracellular structures. They consequently lack a nucleus, mitochondria, 

chloroplasts and the other organelles present in eukaryotic cells, such as the Golgi 

apparatus and endoplasmic reticulum. 

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Paramecia 

Paramecia are a group of unicellular ciliate protozoa formerly known as slipper 

animalcules from their slipper shape. They are commonly studied as a representative of 

the ciliate group. Simple cilia cover the body which allows the cell to move with a 

synchronous motion (like a caterpilla). There is also a deep oral groove containing 

inconspicuous compound oral cilia (as found in other peniculids) that is used to draw 

food inside. They generally feed upon bacteria and other small cells. Osmoregulation is 

carried out by a pair of contractile vacuoles, which actively expel water absorbed by 

osmosis from their surroundings. Paramecia are widespread in freshwater 

environments, and are especially common in scums. Paramecia are attracted by acidic 

conditions. Certain single-celled eukaryotes, such as Paramecium, are examples for 

exceptions to the universality of the genetic code (translation systems where a few 

codons differ from the standard ones). 

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Amoeba 

Amoeba (sometimes amœba or ameba, plural amoebae) is a genus of protozoa that 

moves by means of pseudopods, and is well-known as a representative unicellular 

organism. The word amoeba or ameba is variously used to refer to it and its close 

relatives, now grouped as the Amoebozoa, or to all protozoa that move using 

pseudopods, otherwise termed amoeboids. 

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Vorticella 

Vorticella is a genus of protozoa, with over 100 known species. They are stalked 

inverted bell-shaped ciliates, placed among the peritrichs. Each cell has a separate stalk 

anchored onto the substrate, which contains a contracile fibril called a myoneme. When 

stimulated this shortens, causing the stalk to coil like a spring. Reproduction is by 

budding, where the cell undergoes longitudinal fission and only one daughter keeps the 

stalk. Vorticella mainly lives in freshwater ponds and streams - generally anywhere 

protists are plentiful. Other genera such as Carchesium resemble Vorticella but are 

branched or colonial. 

Domain: Eukaryota 

Phylum: Ciliophora 

Class: Oligohymenophorea 

Subclass: Peritrichia 

Order: Sessilida 

Family: Vorticellidae 

Genus: Vorticella 

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Rotifer 

The rotifers make up a phylum of microscopic and near-microscopic pseudocoelomate 

animals. They were first described by John Harris in 1696 (Hudson and Gosse, 1886). 

Leeuwenhoek is mistakenly given credit for being the first to describe rotifers but Harris 

had produced sketches in 1703. Most rotifers are around 0.1-0.5 mm long, and are 

common in freshwater throughout the world with a few saltwater species. Rotifers may 

be free swimming and truly planktonic, others move by inch worming along the 

substrate, whilst some are sessile, living inside tubes or gelatinous holdfasts. About 25 

species are colonial (e.g. Sinantherina semibullata), either sessile or planktonic. 

Rotifers get their name (derived from Greek and meaning "wheel-bearer"; they have also 

been called wheel animalcules) from the corona, which is composed of several ciliated 

tufts around the mouth that in motion resemble a wheel. These create a current that 

sweeps food into the mouth, where it is chewed up by a characteristic pharynx (called 

the mastax) containing a tiny, calcified, jaw-like structure called the trophi. The cilia also 

pull the animal, when unattached, through the water. Most free-living forms have pairs of 

posterior toes to anchor themselves while feeding. Rotifers have bilateral symmetry and 

a variety of different shapes. There is a well-developed cuticle which may be thick and 

rigid, giving the animal a box-like shape, or flexible, giving the animal a worm-like shape; 

such rotifers are respectively called loricate and illoricate. 

Like many other microscopic animals, adult rotifers frequently exhibit eutely - they have 

a fixed number of cells within a species, usually on the order of one thousand. Males in 

the class Monogononta may be either present or absent depending on the species and 

environmental conditions. In the absence of males, reproduction is by parthenogenesis 

and results in clonal offspring that are genetically identical to the parent. Individuals of 

some species form two distinct types of parthenogenetic eggs; one type develops into a 

normal parthenogenetic female, while the other occurs in response to a changed 

environment and develops into a degenerate male that lacks a digestive system, but 

does have a complete male reproductive system that is used to inseminate females 

thereby producing fertilized 'resting eggs'. Resting eggs develop into zygotes that are 

able to survive extreme environmental conditions such as may occur during winter or 

when the pond dries up. These eggs resume development and produce a new female 

generation when conditions improve again. The life span of monogonont females varies 

from a couple of days to about three weeks. 

Bdelloid rotifers are unable to produce resting eggs, but many can survive prolonged 

periods of adverse conditions after desiccation. This facility is termed anhydrobiosis, and 

organisms with these capabilities are termed anhydrobionts. Under drought conditions, 

bdelloid rotifers contract into an inert form and lose almost all body water; when 

rehydrated, however, they resume activity within a few hours. Bdelloids can survive the 

dry state for prolonged periods, with the longest well-documented dormancy being nine 

years. While in other anhydrobionts, such as the brine shrimp, this desiccation tolerance 

is thought to be linked to the production of trehalose, a non-reducing disaccharide 

(sugar), bdelloids apparently lack the ability to synthesize trehalose. Bdelloid rotifer 

genomes contain two or more divergent copies of each gene. Four copies of hsp82 are, 

for example, found. Each is different and found on a different chromosome, excluding 

the possibility of homozygous sexual reproduction. 

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Waterborne Diseases 

Name Causative organism Source of organism Disease 

Viral 

gastroenteritis 

Rotavirus (mostly in young 

children) 

Norwalk Agent Noroviruses (genus Norovirus, 

family Caliciviridae) *1 

Human feces Diarrhea 

or vomiting 

Human feces; also, 

shellfish; lives in polluted 

waters 

Diarrhea and 

vomiting 

Salmonellosis Salmonella (bacterium) Animal or human feces Diarrhea or 

vomiting 

Gastroenteritis 

Escherichia coli 

-- E. coli O1 57:H7 (bacterium): 

Other E. coli organisms: 

Human feces Symptoms vary 

with type caused 

Typhoid Salmonella typhi (bacterium) Human feces, urine Inflamed intestine, 

enlarged spleen, 

high temperaturesometimes 

fatal 

Shigellosis Shigella (bacterium) Human feces Diarrhea 

Cholera Vibrio choleras (bacterium) Human feces; also, 

shellfish; lives in many 

coastal waters 

Hepatitis A Hepatitis A virus Human feces; shellfish 

grown in polluted waters 

Amebiasis Entamoeba histolytica 

(protozoan) 

Vomiting, severe 

diarrhea, rapid 

dehydration, 

mineral loss-high 

mortality 

Yellowed skin, 

enlarged liver, 

fever, vomiting, 

weight loss, 

abdominal painlow 

mortality, lasts 

up to four months 

Human feces Mild diarrhea, 

dysentery, extra 

intestinal infection 

Giardiasis Giardia lamblia (protozoan) Animal or human feces Diarrhea, 

cramps, nausea, 

and general 

weakness — lasts 

one week to 

months 

Cryptosporidiosis Cryptosporidium parvum Animal or human feces Diarrhea, stomach 

pain — lasts 

(protozoan) days 

to weeks 

Notes: 

*1 http://www.cdc.gov/ncidod/dvrd/revb/gastro/norovirus.htm 

http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5009a1.htm 

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Bacteria Section 

Peritrichous Bacteria 

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Microbiologists broadly classify bacteria according to their shape: spherical, rod-shaped, 

and spiral-shaped. Pleomorphic bacteria can assume a variety of shapes. Bacteria may 

be further classified according to whether they require oxygen (aerobic or anaerobic) 

and how they react to a test with Gram’s stain. Bacteria in which alcohol washes away 

Gram’s stain are called gram-negative, while bacteria in which alcohol causes the 

bacteria’s walls to absorb the stain are called gram-positive. 

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Shigella dysenteriae 

Shigella dysenteriae is a species of the rod-shaped bacterial genus Shigella. Shigella 

can cause shigellosis (bacillary dysentery). Shigellae are Gram-negative, non-sporeforming, 

facultatively anaerobic, non-motile bacteria. 

S. dysenteriae, spread by contaminated water and food, causes the most severe 

dysentery because of its potent and deadly Shiga toxin, but other species may also be 

dysentery agents. Shigella infection is typically via ingestion (fecal–oral contamination); 

depending on age and condition of the host as few as ten bacterial cells can be enough 

to cause an infection. Shigella causes dysentery that result in the destruction of the 

epithelial cells of the intestinal mucosa in the cecum and rectum. Some strains produce 

enterotoxin and Shiga toxin, similar to the verotoxin of E. coli O157:H7. Both Shiga toxin 

and verotoxin are associated with causing hemolytic uremic syndrome. 

Shigella invades the host through epithelial cells of the large intestine. Using a Type III 

secretion system acting as a biological syringe, the bacterium injects IpaD protein into 

cell, triggering bacterial invasion and the subsequent lysis of vacuolar membranes using 

IpaB and IpaC proteins. It utilizes a mechanism for its motility by which its IcsA protein 

triggers actin polymerization in the host cell (via N-WASP recruitment of Arp2/3 

complexes) in a "rocket" propulsion fashion for cell-to-cell spread. 

The most common symptoms are diarrhea, fever, nausea, vomiting, stomach cramps, 

and straining to have a bowel movement. The stool may contain blood, mucus, or pus 

(e.g. dysentery). In rare cases, young children may have seizures. Symptoms can take 

as long as a week to show up, but most often begin two to four days after ingestion. 

Symptoms usually last for several days, but can last for weeks. Shigella is implicated as 

one of the pathogenic causes of reactive arthritis worldwide. 

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Bacteria Types 

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Type Characteristics 

Acetic acid 

Actinomycete 

Coccoid 

Coryneform 

Endospore- 

forming 

Enteric 

Gliding 

Lactic acid 

Mycobacterium 

Mycoplasma 

Nitrogen-fixing 

Propionic acid 

Pseudomonad 

Rickettsia 

Sheathed 

Rod-shaped, gram-negative, aerobic; highly tolerant of acidic 

conditions; generate organic acids 

Rod-shaped or filamentous, gram-positive, aerobic; common in soils; 

essential to growth of many plants; source of much of original antibiotic 

production in pharmaceutical industry 

Spherical, sometimes in clusters or strings, gram-positive, aerobic and 

anaerobic; resistant to drying and high-salt conditions; Staphylococcus 

species common on human skin, certain strains associated with toxic 

shock syndrome 

Rod-shaped, form club or V shapes, gram-positive, aerobic; found in 

wide variety of habitats, particularly soils; highly resistant to drying; 

include Arthrobacter, among most common forms of life on earth 

Usually rod-shaped, can be gram-positive or gram-negative; have 

highly adaptable, heat-resistant spores that can go dormant for long 

periods, possibly thousands of years; include Clostridium (anaerobic) 

and Bacillus (aerobic) 

Rod-shaped, gram-negative, aerobic but can live in certain anaerobic 

conditions; produce nitrite from nitrate, acids from glucose; include 

Escherichia coli, Salmonella (over 1000 types), and Shigella 

Rod-shaped, gram-negative, mostly aerobic; glide on secreted slimy 

substances; form colonies, frequently with complex fruiting structures 

Gram-positive, anaerobic; produce lactic acid through fermentation; 

include Lactobacillus, essential in dairy product formation, and 

Streptococcus, common in humans 

Pleomorphic, spherical or rod-shaped, frequently branching, no gram 

stain, aerobic; commonly form yellow pigments; include Mycobacterium 

tuberculosis, cause of tuberculosis 

Spherical, commonly forming branching chains, no gram stain, aerobic 

but can live in certain anaerobic conditions; without cell walls yet 

structurally resistant to lysis; among smallest of bacteria; named for 

superficial resemblance to fungal hyphae (myco- means 'fungus') 

Rod-shaped, gram-negative, aerobic; convert atmospheric nitrogen gas 

to ammonium in soil; include Azotobacter, a common genus 

Rod-shaped, pleomorphic, gram-positive, anaerobic; ferment lactic 

acid; fermentation produces holes in Swiss cheese from the production 

of carbon dioxide 

Rod-shaped (straight or curved) with polar flagella, gram-negative, 

aerobic; can use up to 100 different compounds for carbon and energy 

Spherical or rod-shaped, gram-negative, aerobic; cause Rocky 

Mountain spotted fever and typhus; closely related to Agrobacterium, a 

common gall-causing plant bacterium 

Filamentous, gram-negative, aerobic; 'swarmer' (colonizing) cells form 

and break out of a sheath; sometimes coated with metals from 

environment 

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Spirillum 

Spirochete 

Sulfate- and 

Sulfurreducing 

Sulfur- and 

iron-oxidizing 

Vibrio 

Spiral-shaped, gram-negative, aerobic; include Bdellovibrio, predatory 

on other bacteria 

Spiral-shaped, gram-negative, mostly anaerobic; common in moist 

environments, from mammalian gums to coastal mudflats; complex 

internal structures convey rapid movement; include 

Treponemapallidum, cause of syphilis 

Commonly rod-shaped, mostly gram-negative, anaerobic; include 

Desulfovibrio, ecologically important in marshes 

Commonly rod-shaped, frequently with polar flagella, gram-negative, 

mostly anaerobic; most live in neutral (nonacidic) environment 

Rod- or comma-shaped, gram-negative, aerobic; commonly with a 

single flagellum; include Vibrio cholerae, cause of cholera, and 

luminescent forms symbiotic with deep-water fishes and squids 

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Salmonella 

Salmonella is a Gram-negative bacterium. It is found in many turtles and other reptiles. 

In clinical laboratories, it is usually isolated on MacConkey agar, XLD agar, XLT agar, 

DCA agar, or Önöz agar. Because they cause intestinal infections and are greatly 

outnumbered by the bacteria normally found in the healthy bowel, primary isolation 

requires the use of a selective medium, so use of a relatively non-selective medium such 

as CLED agar is not often practiced. Numbers of salmonella may be so low in clinical 

samples that stools are routinely also subjected to "enrichment culture", where a small 

volume of stool is incubated in a selective broth medium, such as selenite broth or 

Rappaport Vassiliadis soya peptone broth, overnight. These media are inhibitory to the 

growth of the microbes normally found in the healthy human bowel, while allowing 

salmonellae to become enriched in numbers. Salmonellae may then be recovered by 

inoculating the enrichment broth on one or more of the primary selective media. On 

blood agar, they form moist colonies about 2 to 3 mm in diameter. 

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When the cells are grown for a prolonged time at a range of 25—28°C, some strains 

produce a biofilm, which is a matrix of complex carbohydrates, cellulose and proteins. 

The ability to produce biofilm (a.k.a. "rugose", "lacy", or "wrinkled") can be an indicator of 

dimorphism, which is the ability of a single genome to produce multiple phenotypes in 

response to environmental conditions. Salmonellae usually do not ferment lactose; most 

of them produce hydrogen sulfide which, in media containing ferric ammonium citrate, 

reacts to form a black spot in the centre of the creamy colonies. 

Classification 

Salmonella taxonomy is complicated. As of December 7, 2005, there are two species 

within the genus: S. bongori 

(previously subspecies V) and 

S. enterica (formerly called 

S. choleraesuis), which is divided 

into six subspecies: 

* I—enterica 

* II—salamae 

* IIIa—arizonae 

* IIIb—diarizonae 

* IV—houtenae 

* V—obsolete (now designated 

S. bongori) 

* VI—indica 

There are also numerous (over 

2500) serovars within both species, 

which are found in a disparate 

variety of environments and which 

are associated with many different 

diseases. The vast majority of 

human isolates (>99.5%) are 

subspecies S. enterica. For the 

sake of simplicity, the CDC 

recommends that Salmonella 

species be referred to only by their 

genus and serovar, e.g. 

Salmonella Typhi instead of the 

more technically correct 

designation, Salmonella enterica subspecies enterica serovar Typhi. 

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Escherichia Coli Section 

Fecal Coliform Bacteria 

Fecal coliform bacteria are microscopic organisms that live in the intestines of warmblooded 

animals. They also live in the waste material, or feces, excreted from the 

intestinal tract. When fecal coliform bacteria are present in high numbers in a water 

sample, it means that the water has received fecal matter from one source or another. 

Although not necessarily agents of disease, fecal coliform bacteria may indicate the 

presence of disease-carrying organisms, which live in the same environment as the fecal 

coliform bacteria. 

Reasons for Natural Variation 

Unlike the other conventional water quality parameters, fecal coliform bacteria are living 

organisms. They do not simply mix with the water and float straight downstream. Instead 

they multiply quickly when conditions are favorable for growth, or die in large numbers 

when conditions are not. Because bacterial concentrations are dependent on specific 

conditions for growth, and these conditions change quickly, fecal coliform bacteria 

counts are not easy to predict. For example, although winter rains may wash more fecal 

matter from urban areas into a stream, cool water temperatures may cause a major dieoff. 

Exposure to sunlight (with its ultraviolet disinfection properties) may have the same 

effect, even in the warmer water of summertime. 

Expected Impact of Pollution 

The primary sources of fecal coliform bacteria 

to fresh water are wastewater treatment plant 

discharges, failing septic systems, and animal 

waste. Bacteria levels do not necessarily 

decrease as a watershed develops from rural to 

urban. Instead, urbanization usually generates 

new sources of bacteria. Farm animal manure 

and septic systems are replaced by domestic 

pets and leaking sanitary sewers. In fact, 

stormwater runoff in urbanized areas has been 

found to be surprisingly high in fecal coliform 

bacteria concentrations. 

The presence of old, disintegrating storm and 

sanitary sewers, misplaced sewer pipes, and 

good breeding conditions are common 

explanations for the high levels measured. 

Coliform Standards (in colonies/100ml ) 

Drinking water..................................................................1FC 

Total body contact (swimming).............................................200FC 

Partial body contact (boating)..............................................1000FC 

Threatened sewage effluent ................................not to exceed 200 FC 

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*Total coliform (TC) includes bacteria from cold-blooded animals and various soil 

organisms. According to recent literature, total coliform counts are normally about 10 

times higher than fecal coliform (FC) counts. 

Indicator Connection Varies 

General coliforms, E. Coli, and Enterococcus bacteria are the "indicator" organisms 

generally measured to assess microbiological quality of water. However, these aren't 

generally what get people sick. Other bacteria, viruses, and parasites are what we are 

actually worried about. 

Because it is so much more expensive and tedious to do so, actual pathogens are 

virtually never tested for. Over the course of a professional lifetime pouring over indicator 

tests, in a context where all standards are based on indicators, water workers tend to 

forget that the indicators are not the things we actually care about. 

What are these indicators? More information in the Laboratory section. 

� General coliforms indicate that the water has come in contact with plant or 

animal life. General coliforms are universally present, including in pristine spring 

water. They are of little concern at low levels, except to indicate the effectiveness 

of disinfection. Chlorinated water and water from perfectly sealed tube wells is 

the only water I've tested which had zero general coliforms. At very high levels 

they indicate there is what amounts to a lot of compost in the water, which could 

easily include pathogens (Ten thousand general coliform bacteria will get you a 

beach closure, compared to two or four hundred fecal coliforms, or fifty 

enterococcus). 

� Fecal coliforms, particularly E. coli, indicate that there are mammal or bird feces 

in the water. 

� Enterococcus bacteria also indicate that there are feces from warm blooded 

animals in the water. Enterococcus are a type of fecal streptococci. They are 

another valuable indicator for determining the amount of fecal contamination of 

water. 

According to studies conducted by the EPA, enterococci have a greater 

correlation with swimming-associated gastrointestinal illness in both marine and 

fresh waters than other bacterial indicator organisms, and are less likely to "die 

off" in saltwater. 

The more closely related the animal, the more likely pathogens excreted with their feces 

can infect us. Human feces are the biggest concern, because anything which infects one 

human could infect another. There isn't currently a quantitative method for measuring 

specifically human fecal bacteria (expensive genetic studies can give a 

presence/absence result). Ingesting a human stranger's feces via contaminated water 

supply is a classic means for infections to spread rapidly. The more pathogens an 

individual carries, the more hazardous their feces. Ingesting feces from someone who is 

not carrying any pathogens may gross you out, but it can't infect you. Infection rates are 

around 5% in the US, and approach 100% in areas with poor hygiene and contaminated 

water supplies. Keep in the back of your mind that the ratio of indicators to actual 

pathogens is not fixed. It will always be different, sometimes very different. Whenever 

you are trying to form a mental map of reality based on water tests, you should include in 

the application of your water intuition an adjustment factor for your best guess of the 

ratio between indicators and actual pathogens. 

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Membrane Filter Total Coliform Technique 

The membrane filter total Coliform technique is used at Medina County for drinking water 

quality testing. The following is a summary of this test. A sampling procedure sheet is 

given to all sample takers by Medina County. 

The samples are taken in sterile 100 mL containers. These containers, when used for 

chlorinated water samples, have a sodium thiosulfate pill or solution to dechlorinate the 

sample. 

The sample is placed in cold storage after proper sample taking procedures are 

followed. (See sample 

procedures below) 

The samples are taken to the 

laboratory with a chain of 

custody to assure no 

tampering of samples can 

occur. 

These samples are logged in 

at the laboratory. 

No longer than 30 hours can 

lapse between the time of 

sampling and time of test 

incubation. (8 hours for 

heterotrophic, nonpotable 6 

hours, others not longer than 

24 hours) 

All equipment is sterilized by oven and autoclave. 

Glassware in oven at 170 o C + 10 o C with foil (or other suitable wrap) loosely fitting and 

secured immediately after sterilization. 

Filtration units in autoclave at 121 o C for 30 

minutes. 

Use sterile petri dishes, grid, and pads 

bought from a reliable company – certified, 

quality assured - test for satisfactory known 

positive amounts. 

Incubators – 35 o C + .5 o C (60% relative 

humidity) 

M-endo medium is prepared and heated to 

near boiling removed from heat cooled to 

45 o C pH adjusted to 7.2 + .2 and 

immediately dispensed 8ml to plates. Keep 

refrigerated and discard after 2 weeks. 

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Plates can be stored in a dated box with expiration date and discarded if not used. No 

denatured alcohol should be used. Everclear or 95% proof alcohol or absolute methyl 

may be used for sterilizing forceps by flame. 

Procedure: 

Counters are alcohol wiped. 

Bench sheets are filled out. 

Samples are removed from refrigeration. 

Sterile wrapped utensils are placed on counters. 

Filtration units are placed onto sterile membrane filters by aseptic technique using sterile 

forceps. 

Sterile petri dishes are labeled. 

The samples closures are clipped. 

The sample is shaken 25 times 1 foot in length within 7 seconds. 

100 mL is filtered and rinsed with sterile distilled water 3 times. 

The membrane filter is aseptically removed from filter holder. 

A sterile padded petri dish is used and the membrane filter is rolled onto the pad making 

sure no air bubbles form. 

The sterile labeled lid is placed on the petri dish. 

2 blanks and a known is run with each series of samples. 

The samples are placed in the 35 o C + .5 o C incubator stacked no higher than 3 for 22 – 

24 hours (Humidity can be maintained by saturated paper towels placed under 

containers holding petri dishes.) 

After 22- 24 hours view the petri dishes under a 10 –15 power magnification with cool 

white fluorescent light. 

Count all colonies that appear pink to dark red with a metallic surface sheen – the sheen 

may vary in size from a pin head to complete coverage. 

Report as Total Coliform per 100 mL. 

If no colonies are present report as

Escherichia coli EPEC 

Two types of pathogenic Escherichia coli, enteropathogenic E. coli (EPEC) and 

enterohemorrhagic E. coli (EHEC), cause diarrheal disease by disrupting the intestinal 

environment through the intimate attachment of the bacteria to the intestinal epithelium. 

E. coli O157:H7 

E. coli O157:H7 (bacterium) found in human feces. Symptoms vary with type caused 

gastroenteritis. 

Escherichia coli O157:H7 is an emerging cause of foodborne illness. An estimated 

73,000 cases of infection and 61 deaths occur in the United States each year. Infection 

often leads to bloody diarrhea, and occasionally to kidney failure. Most illnesses have 

been associated with eating undercooked, contaminated ground beef. Person-to-person 

contact in families and child care centers is also an important mode of transmission. 

Infection can also occur after drinking raw milk and after swimming in or drinking 

sewage-contaminated water. 

Consumers can prevent E. coli O157:H7 infection by thoroughly cooking ground beef, 

avoiding unpasteurized milk, and washing hands carefully. Because the organism lives 

in the intestines of healthy cattle, preventive measures on cattle farms and during meat 

processing are being investigated. 

What is Escherichia coli O157:H7? 

E. coli O157:H7 is one of hundreds of strains of the bacterium Escherichia coli. Although 

most strains are harmless and live in the intestines of healthy humans and animals, this 

strain produces a powerful toxin and can cause severe illness. 

E. coli O157:H7 was first recognized as a cause of illness in 1982 during an outbreak of 

severe bloody diarrhea; the outbreak was traced to contaminated hamburgers. Since then, 

most infections have come from eating undercooked ground beef. 

The combination of letters and numbers in the name of the bacterium refers to the specific 

markers found on its surface and distinguishes it from other types of E. coli. 

Currently, there are four recognized classes of enterovirulent E. coli (collectively referred to 

as the EEC group) that cause gastroenteritis in humans. Among these is the 

enterohemorrhagic (EHEC) strain designated E. coli O157:H7. E. coli is a normal inhabitant 

of the intestines of all animals, including humans. When aerobic culture methods are used, 

E. coli is the dominant species found in feces. 

Normally E. coli serves a useful function in the body by suppressing the growth of harmful 

bacterial species and by synthesizing appreciable amounts of vitamins. A minority of E. coli 

strains are capable of causing human illness by several different mechanisms. E. coli 

serotype O157:H7 is a rare variety of E. coli that produces large quantities of one or more 

related, potent toxins that cause severe damage to the lining of the intestine. These toxins 

[verotoxin (VT), shiga-like toxin] are closely related or identical to the toxin produced by 

Shigella dysenteriae. 

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How does E. coli or other fecal coliforms get in the water? 

E. coli comes from human and animal wastes. During rainfalls, snow melts, or other types of 

precipitation, E. coli may be washed into creeks, rivers, streams, lakes, or groundwater. When 

these waters are used as sources of drinking water and the water is not treated or 

inadequately treated, E. coli may end up in drinking water. 

How is water treated to protect me from E. coli? 

The water can be treated using chlorine, ultra-violet light, or ozone, all of which act to kill or 

inactivate E. coli. Systems using surface water sources are required to disinfect to ensure that 

all bacterial contamination such as E. coli. is inactivated. Systems using ground water sources 

are not required to disinfect, although many of them do. 

How does the U.S. Environmental Protection Agency regulate E. coli? 

According to EPA regulations, a system that operates at least 60 days per year, and serves 25 

people or more or has 15 or more service connections, is regulated as a public water system 

under the Safe Drinking Water Act. If a system is not a public water system as defined by 

EPA regulations, it is not regulated under the Safe Drinking Water Act, although it may be 

regulated by state or local authorities. 

Under the Safe Drinking Water Act, the EPA requires public water systems to monitor for 

coliform bacteria. Systems analyze first for total coliform, because this test is faster to produce 

results. Any time that a sample is positive for total coliform, the same sample must be 

analyzed for either fecal coliform or E. coli. Both are indicators of contamination with animal 

waste or human sewage. 

The largest public water systems (serving millions of people) must take at least 480 samples 

per month. Smaller systems must take at least five samples a month unless the state has 

conducted a sanitary survey – a survey in which a state inspector examines system 

components and ensures they will protect public health – at the system within the last five 

years. 

Systems serving 25 to 1,000 people typically take one sample per month. Some states reduce 

this frequency to quarterly for ground water systems if a recent sanitary survey shows that the 

system is free of sanitary defects. Some types of systems can qualify for annual monitoring. 

Systems using surface water, rather than ground water, are required to take extra steps to 

protect against bacterial contamination because surface water sources are more vulnerable to 

such contamination. At a minimum, all systems using surface waters must 

disinfect. Disinfection will kill E. coli O157:H7. 

What can I do to protect myself from E. coli O157:H7 in drinking water? 

Approximately 89 percent of Americans are receiving water from community water systems 

that meet all health-based standards. Your public water system is required to notify you if, for 

any reason, your drinking water is not safe. If you wish to take extra precautions, you can boil 

your water for one minute at a rolling boil, longer at higher altitudes. To find out more 

information about your water, see the Consumer Confidence Report from your local water 

supplier or contact your local water supplier directly. You can also obtain information about 

your local water system on the EPA's website at www.epa.gov/safewater/dwinfo.htm. 

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Positive Tests 

If you draw water from a private well, you can contact your state health department to obtain 

information on how to have your well tested for total coliforms, and E. coli contamination. If 

your well tests positive for E. coli, there are several steps that you should take: (1) begin 

boiling all water intended for consumption, (2) disinfect the well according to procedures 

recommended by your local health department, and (3) monitor your water quality to make 

certain that the problem does not recur. If the contamination is a recurring problem, you 

should investigate the feasibility of drilling a new well or install a point-of-entry disinfection unit, 

which can use chlorine, ultraviolet light, or ozone. 

How is E. coli O157:H7 spread? 

The organism can be found on a small number of cattle farms and can live in the intestines of 

healthy cattle. Meat can become contaminated during slaughter, and organisms can be 

thoroughly mixed into beef when it is ground. Bacteria present on a cow's udders or on 

equipment may get into raw milk. Eating meat, especially ground beef that has not been 

cooked sufficiently to kill E. coli O157:H7 can cause infection. Contaminated meat looks and 

smells normal. Although the number of organisms required to cause disease is not known, it is 

suspected to be very small. 

Among other known sources of infection are consumption of sprouts, lettuce, salami, 

unpasteurized milk and juice, and swimming in or drinking sewage-contaminated water. 

Bacteria in diarrheal stools of infected persons can be passed from one person to another if 

hygiene or hand washing habits are inadequate. This is particularly likely among toddlers who 

are not toilet trained. Family members and playmates of these children are at high risk of 

becoming infected. Young children typically shed the organism in their feces for a week or two 

after their illness resolves. Older children rarely carry the organism without symptoms. 

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What illness does E. coli O157:H7 cause? 

E. coli O157:H7 infection often causes severe bloody diarrhea and abdominal cramps; 

sometimes the infection causes non-bloody diarrhea or no symptoms. Usually little or no fever 

is present, and the illness resolves in 5 to 10 days. Hemorrhagic colitis is the name of the 

acute disease caused by E. coli O157:H7. 

In some persons, particularly children under 5 years of age and the elderly, the infection can 

also cause a complication called hemolytic uremic syndrome, in which the red blood cells are 

destroyed and the kidneys fail. About 2%-7% of infections lead to this complication. In the 

United States, hemolytic uremic syndrome is the principal cause of acute kidney failure in 

children, and most cases of hemolytic uremic syndrome are caused by E. coli O157:H7. 

How is E. coli O157:H7 infection diagnosed? 

Infection with E. coli O157:H7 is diagnosed by detecting the bacterium in the stool. Most 

laboratories that culture stool do not test for E. coli O157:H7, so it is important to request that 

the stool specimen be tested on sorbitol-MacConkey (SMAC) agar for this organism. All 

persons who suddenly have diarrhea with blood should get their stool tested for E. coli 

O157:H7. 

How is the illness treated? 

Most persons recover without antibiotics or other specific treatment in 5-10 days. There is no 

evidence that antibiotics improve the course of disease, and it is thought that treatment with 

some antibiotics may precipitate kidney complications. Antidiarrheal agents, such as 

loperamide (Imodium), should also be avoided. Hemolytic uremic syndrome is a lifethreatening 

condition usually treated in an intensive care unit. Blood transfusions and kidney 

dialysis are often required. With intensive care, the death rate for hemolytic uremic syndrome 

is 3%-5%. 

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Legionnaires' Disease Legionella Section 

Introduction Genus: Legionella Species: pneumophila 

The first discovery of bacteria from genus Legionella came in 1976 when an outbreak of 

pneumonia at an American Legion convention led to 29 deaths. The causative agent, what 

would come to be known as Legionella pneumophila, was isolated and given its own genus. 

The organisms classified in this genus are Gram-negative bacteria that are considered 

intracellular parasites. The disease has two distinct 

forms: 

� Legionnaires' disease, the more severe form of 

infection which includes pneumonia, and 

� Pontiac fever, a milder illness. 

What have been the water sources for 

Legionnaires' disease? 

The major source is water distribution systems of large 

buildings, including hotels and hospitals. Cooling 

towers have long been thought to be a major source for 

Legionella, but new data suggest that this is an overemphasized mode of transmission. Other 

sources include mist machines, humidifiers, whirlpool spas, and hot springs. Air conditioners 

are not a source for Legionnaires' disease. They were suspected to be the source in the 

original American Legion outbreak in a Philadelphia hotel, 

but new data now suggests that the water in the hotel was 

the actual culprit. 

Legionnaire’s disease is caused most commonly by the 

inhalation of small droplets of water or fine aerosol 

containing Legionella bacteria. Legionella bacteria are 

naturally found in environmental water sources such as 

rivers, lakes and ponds and may colonize man-made water 

systems that include air conditioning systems, humidifiers, 

cooling tower waters, hot water systems, spas and pools. 

How do people contract Legionella? 

The most popular theory is that the organism is aerosolized 

in water and people inhale the droplets containing Legionella. However, new evidence 

suggests that another way of contracting Legionella is more common. "Aspiration" is the most 

common way that bacteria enter into the lungs to cause pneumonia. Aspiration means 

choking such that secretions in the mouth get past the choking reflexes and instead of going 

into the esophagus and stomach, mistakenly, enter the lung. The protective mechanisms to 

prevent aspiration is defective in patients who smoke or have lung disease. Aspiration now 

appears to be the most common mode of transmission. 

Legionella may multiply to high numbers in cooling towers, evaporative condensers, air 

washers, humidifiers, hot water heaters, spas, fountains, and plumbing fixtures. Within one 

month, Legionella can multiply, in warm water-containing systems, from less than 10 per 

milliliter to over 1,000 per milliliter of water. Once high numbers of Legionella have been found, 

a relatively simple procedure for disinfecting water systems with chlorine and detergent is 

available. This procedure is not part of a routine maintenance program because equipment 

may become corroded. 

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Property owners have been sued for the spread of Legionella, resulting in expensive 

settlements. Regular monitoring with a battery of DFA monoclonal antibodies for several 

serogroups and species of Legionella morphologically intact bacteria provides a means for 

exercising 'reasonable care' to deter potential litigation. 

Currently, there are no United States government regulations concerning permissible numbers 

of legionella in water systems and there are no federal or state certification programs for 

laboratories that perform legionella testing of environmental samples. 

Epifluorescence Microscopy DFA Method 

The epifluorescence microscopy DFA method that most labs use was published in the British 

Journal, Water Research 19:839-848, 1985 "Disinfection of circulating water systems by 

ultraviolet light and halogenation", R. Gilpin, et al. so we can count viable-but-nonculturable 

(VBNC) legionella. 

Most labs will provide a quantitative epifluorescence microscopic analysis of your cooling 

tower and potable water samples for 14 serogroups of Legionella pneumophila and 15 other 

Legionella species (listed below). 

Legionella anisa Legionella bozemanii sg 1 & 2 

Legionella dumoffi Legionella feeleii sg 1 & 2 

Legionella gormanii Legionella hackeliae sg 1 & 2 

Legionella jordanis Legionella longbeachae sg 1& 2 

Legionella maceachernii Legionella micdadei 

Legionella oakridgensis Legionella parisiensis 

Legionella pneumophila sg 1-14 Legionella sainthelensi 

Legionella santicrucis Legionella wadsworthii 

Heterotrophic bacterial CFU are often inversely proportional to numbers of Legionella in 

cooling tower samples, in our experience. Routine biocide treatments will not eradicate 

Legionella bacteria in the environment, only in laboratory studies. 

Culture methods are good during outbreaks for bio-typing; but culture methods lack sensitivity 

for routine, quantitative monitoring. Many factors will inhibit growth or identification of legionella 

on BCYE with or without antimicrobial agents, heat or acid treatment. 

Culture methods will not identify non-culturable legionella that can still cause outbreaks (nonculturable, 

viable legionella have been reported in several peer-reviewed journals). Only DFA 

tests performed by trained laboratory personnel can identify these legionella. Direct 

fluorescent antibody (DFA) tests using a battery of monoclonal antibodies provide more useful 

routine monitoring information than culture methods. Legionella species of bacteria cause 

Legionnaire's disease. They are gram negative (but stain poorly), strictly aerobic rods. 

The U.S. Environmental Protection Agency and the U.S. Occupational Safety and Health 

Administration recommend routine maintenance of water-containing equipment. Most State 

health departments recommend monthly testing for Legionella as part of a routine 

maintenance program. 

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Bacteriophage 

A bacteriophage (from 'bacteria' and Greek phagein, 'to eat') is any one of a number of viruses 

that infect bacteria. The term is commonly used in its shortened form, phage. 

Typically, bacteriophages consist of an outer protein hull enclosing genetic material. The 

genetic material can be ssRNA (single stranded RNA), dsRNA, ssDNA, or dsDNA between 5 

and 500 kilo base pairs long with either circular or linear arrangement. Bacteriophages are 

much smaller than the bacteria they destroy - usually between 20 and 200 nm in size. 

Phages are estimated to be the most widely distributed and diverse entities in the biosphere. 

Phages are ubiquitous and can be found in all reservoirs populated by bacterial hosts, such as 

soil or the intestine of animals. One of the densest natural sources for phages and other 

viruses is sea water, where up to 9×108 virions per milliliter have been found in microbial mats 

at the surface, and up to 70% of marine bacteria may be infected by phages. 

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Release of Virions 

Phages may be released via cell lysis or by host cell secretion. In the case of the T4 phage, in 

just over twenty minutes after injection upwards of three hundred phages will be released via 

lysis within a certain timescale. This is achieved by an enzyme called endolysin which attacks 

and breaks down the peptidoglycan. In contrast, "lysogenic" phages do not kill the host but 

rather become long-term parasites and make the host cell continually secrete more new virus 

particles. The new virions bud off the plasma membrane, taking a portion of it with them to 

become enveloped viruses possessing a viral envelope. All released virions are capable of 

infecting a new bacterium. 

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Viruses 

Viruses are acellular microorganisms. They are made up of only genetic material and a protein 

coat. Viruses depend on the energy and metabolic machinery of the host cell to reproduce. A 

virus is an infectious agent found in virtually all life forms, including humans, animals, plants, 

fungi, and bacteria. Viruses consist of genetic material—either deoxyribonucleic acid (DNA) or 

ribonucleic acid (RNA)—surrounded by a protective coating of protein, called a capsid, with or 

without an outer lipid envelope. Viruses are between 20 and 100 times smaller than bacteria 

and hence are too small to be seen by light microscopy. 

Viruses vary in size from the largest poxviruses of about 450 nanometers (about 0.000014 in) 

in length to the smallest polioviruses of about 30 nanometers (about 0.000001 in). Viruses are 

not considered free-living, since they cannot reproduce outside of a living cell; they have 

evolved to transmit their genetic information from one cell to another for the purpose of 

replication. Viruses often damage or kill the cells that they infect, causing disease in infected 

organisms. A few viruses stimulate cells to grow uncontrollably and produce cancers. Although 

many infectious diseases, such as the common cold, are caused by viruses, there are no 

cures for these illnesses. The difficulty in developing antiviral therapies stems from the large 

number of variant viruses that can cause the same disease, as well as the inability of drugs to 

disable a virus without disabling healthy cells. However, the development of antiviral agents is 

a major focus of current research, and the study of viruses has led to many discoveries 

important to human health. 

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Virions 

Individual viruses, or virus particles, also called virions, contain genetic material, or genomes, 

in one of several forms. Unlike cellular organisms, in which the genes always are made up of 

DNA, viral genes may consist of either DNA or RNA. Like cell DNA, almost all viral DNA is 

double-stranded, and it can have either a circular or a linear arrangement. Almost all viral RNA 

is single-stranded; it is usually linear, and it may be either segmented (with different genes on 

different RNA molecules) or non-segmented (with all genes on a single piece of RNA). 

Capsids 

The viral protective shell, or capsid, can be either helical (spiral-shaped) or icosahedral 

(having 20 triangular sides). Capsids are composed of repeating units of one or a few different 

proteins. These units are called protomers or capsomers. The proteins that make up the virus 

particle are called structural proteins. Viruses also carry genes for making proteins that are 

never incorporated into the virus particle and are found only in infected cells. These viral 

proteins are called nonstructural proteins; they include factors required for the replication of 

the viral genome and the production of the virus particle. 

Capsids and the genetic material (DNA or RNA) they contain are together referred to as 

nucleocapsids. Some virus particles consist only of nucleocapsids, while others contain 

additional structures. 

Some icosahedral and helical animal viruses are enclosed in a lipid envelope acquired when 

the virus buds through host-cell membranes. Inserted into this envelope are glycoproteins that 

the viral genome directs the cell to make; these molecules bind virus particles to susceptible 

host cells. 

Bacteriophages 

The most elaborate viruses are the bacteriophages, which use bacteria as their hosts. Some 

bacteriophages resemble an insect with an icosahedral head attached to a tubular sheath. 

From the base of the sheath extend several long tail fibers that help the virus attach to the 

bacterium and inject its DNA to be replicated, direct capsid production, and virus particle 

assembly inside the cell. 

Viroids and Prions 

Viroids and prions are smaller than viruses, but they are similarly associated with disease. 

Viroids are plant pathogens that consist only of a circular, independently replicating RNA 

molecule. The single-stranded RNA circle collapses on itself to form a rod-like structure. The 

only known mammalian pathogen that resembles plant viroids is the deltavirus (hepatitis D), 

which requires hepatitis B virus proteins to package its RNA into virus particles. Co-infection 

with hepatitis B and D can produce more severe disease than can infection with hepatitis B 

alone. Prions are mutated forms of a normal protein found on the surface of certain animal 

cells. 

Virus Classification 

Viruses are classified according to their type of genetic material, their strategy of replication, 

and their structure. The International Committee on Nomenclature of Viruses (ICNV), 

established in 1966, devised a scheme to group viruses into families, subfamilies, genera, and 

species. The ICNV report published in 1995 assigned more than 4000 viruses into 71 virus 

families. Hundreds of other viruses remain unclassified because of the lack of sufficient 

information. 

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Cyanobacteria 

Cyanobacteria 

Cyanobacteria, also known as blue-green algae, blue-green bacteria or Cyanophyta, is a 

phylum of bacteria that obtain their energy through photosynthesis. The name "cyanobacteria" 

comes from the color of the bacteria (Greek: kyanós = blue). They are a significant component 

of the marine nitrogen cycle and an important primary producer in many areas of the ocean, 

but are also found on land. 

Cyanobacteria include unicellular and colonial species. Colonies may form filaments, sheets or 

even hollow balls. Some filamentous colonies show the ability to differentiate into several 

different cell types: vegetative cells, the normal, photosynthetic cells that are formed under 

favorable growing conditions; akinetes, the climate-resistant spores that may form when 

environmental conditions become harsh; and thick-walled heterocysts, which contain the 

enzyme nitrogenase, vital for nitrogen fixation. Heterocysts may also form under the 

appropriate environmental conditions (anoxic) wherever nitrogen is necessary. Heterocystforming 

species are specialized for nitrogen fixation and are able to fix nitrogen gas, which 

cannot be used by plants, into ammonia (NH3), nitrites (NO2) or nitrates (NO3), which can be 

absorbed by plants and converted to protein and nucleic acids. 

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The rice paddies of Asia, which produce about 75% of the world's rice, could not do so were it 

not for healthy populations of nitrogen-fixing cyanobacteria in the rice paddy fertilizer too. 

Many cyanobacteria also form motile filaments, called hormogonia, that travel away from the 

main biomass to bud and form new colonies elsewhere. The cells in a hormogonium are often 

thinner than in the vegetative state, and the cells on either end of the motile chain may be 

tapered. In order to break away from the parent colony, a hormogonium often must tear apart 

a weaker cell in a filament, called a necridium. 

Each individual cell of a cyanobacterium typically has a thick, gelatinous cell wall. They differ 

from other gram-negative bacteria in that the quorum sensing molecules autoinducer-2[4] and 

acyl-homoserine lactones are absent. They lack flagella, but hormogonia and some unicellular 

species may move about by gliding along surfaces. In water columns some cyanobacteria float 

by forming gas vesicles, like in archaea. 

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Euglena 

Euglenas are common protists, of the class Euglenoidea of the phylum Euglenophyta. 

Currently, over 1000 species of Euglena have been described. Marin et al. (2003) revised the 

genus so, and including several species without chloroplasts, formerly classified as Astasia 

and Khawkinea. Euglena sometimes can be considered to have both plant and animal 

features. 

Euglena gracilis has a long hair-like thing that stretches from its body. You need a very 

powerful microscope to see it. This is called a flagellum, and the euglena uses it to swim. It 

also has a red eyespot. Euglena gracilis uses its eyespot to locate light. Without light, it cannot 

use its chloroplasts to make itself food. In order for Euglena gracilis to make more Euglena 

gracilis it will complete a process called mitosis. That means it can split itself in half and 

become two Euglena gracilis. It can only do this if it is well-fed and if the temperature is right. 

Euglena gracilis can reproduce better in warm temperatures. 

Euglena gracilis, and other euglena, are harmless to people, but they are often signs that 

water is polluted, since they do well where there is a lot of green algae to eat. Green algae 

does well where there is a lot of nitrogen (comes from waste) in the water. If you don't clean 

your swimming pool, leaves and twigs get in the water and turn into waste. Then algae and 

euglena show up. 

KINGDOM: Protist, PHYLUM: Euglenophyta, CLASS: Euglenophyceae, ORDER: 

Euglenales, FAMILY: Euglenidae, GENUS: Euglena, SPECIES: Euglena gracilis 

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Peptidoglycan 

Peptidoglycan, also known as murein, is a polymer consisting of sugars and amino acids that 

forms a mesh-like layer outside the plasma membrane of eubacteria. The sugar component 

consists of alternating residues of β-(1,4) linked N-acetylglucosamine and N-acetylmuramic 

acid residues. Attached to the N-acetylmuramic acid is a peptide chain of three to five amino 

acids. The peptide chain can be cross-linked to the peptide chain of another strand forming the 

3D mesh-like layer. 

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Hepatitis 

There are five types of hepatitis -- A through E -- all of which cause inflammation of the liver. 

Type D affects only those who also have hepatitis B, and hepatitis E is extremely rare in the 

United States. 

� Type A hepatitis is contracted through anal-oral contact, by coming in contact with the 

feces of someone with hepatitis A, or by eating or drinking hepatitis A contaminated 

food or water. 

� Type B hepatitis can be contracted from infected blood, seminal fluid, vaginal 

secretions, or contaminated drug needles, including tattoo or body-piercing equipment. 

It can also be spread from a mother to her newborn. 

� Type C hepatitis is not easily spread through sex. You're more likely to get it through 

contact with infected blood, contaminated razors, needles, tattoo and body-piercing 

equipment, or manicure or pedicure tools that haven't been properly sanitized, and a 

mother can pass it to her baby during delivery. 

� Type D hepatitis can be passed through contact with infected blood, contaminated 

needles, or by sexual contact with an HIV-infected person. 

� Type E hepatitis is most likely to be transmitted in feces, through oral contact, or in 

water that's been contaminated. 

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Math Conversion Factors and Practical Exercise 

1 PSI = 2.31 Feet of Water LENGTH 

1 Foot of Water = .433 PSI 12 Inches = 1 Foot 

1.13 Feet of Water = 1 Inch of Mercury 3 Feet = 1 Yard 

454 Grams = 1 Pound 5280 Feet = 1 Mile 

2.54 CM =Inch 

1 Gallon of Water = 8.34 Pounds AREA 

1 mg/L = 1 PPM 144 Square Inches = 1 Square Foot 

17.1 mg/L = 1 Grain/Gallon 43,560 Square Feet =1 Acre 

1% = 10,000 mg/L VOLUME 

694 Gallons per Minute = MGD 1000 Milliliters = 1 Liter 

1.55 Cubic Feet per Second = 1 MGD 3.785 Liters = 1 Gallon 

60 Seconds = 1 Minute 231 Cubic Inches = 1 Gallon 

1440 Minutes = 1 Day 7.48 Gallons = 1 Cubic Foot of water 

.746 kW = 1 Horsepower 62.38 Pounds = 1 Cubic Foot of water 

Dimensions 

SQUARE: Area (sq.ft.) = Length X Width 

Volume (cu.ft.) = Length (ft) X Width (ft) X Height (ft) 

CIRCLE: Area (sq.ft.) = 3.14 X Radius (ft) X Radius (ft) 

CYLINDER: Volume (Cu. ft) = 3.14 X Radius (ft) X Radius (ft) X Depth (ft) 

PIPE VOLUME: .785 X Diameter 2 X Length = ? To obtain gallons multiply by 7.48 

SPHERE: (3.14) (Diameter) 3 Circumference = 3.14 X Diameter 

(6) 

General Conversions 

Flowrate 

Multiply —> to get 

to get

PERCENT EFFICIENCY = In – Out X 100 

In 

TEMPERATURE: 

0 F = ( 0 C X 9/5) + 32 9/5 =1.8 

0 C = ( 0 F - 32) X 5/9 5/9 = .555 

CONCENTRATION: Conc. (A) X Volume (A) = Conc. (B) X Volume (B) 

FLOW RATE (Q): Q = A X V (Quantity = Area X Velocity) 

FLOW RATE (gpm): Flow Rate (gpm) = 2.83 (Diameter, in) 2 (Distance, in) 

Height, in 

% SLOPE = Rise (feet) X 100 

Run (feet) 

ACTUAL LEAKAGE = Leak Rate (GPD) 

Length (mi.) X Diameter (in) 

VELOCITY = Distance (ft) 

Time (Sec) 

N = Manning’s Coefficient of Roughness 

R = Hydraulic Radius (ft.) 

S = Slope of Sewer (ft/ft.) 

HYDRAULIC RADIUS (ft) = Cross Sectional Area of Flow (ft) 

Wetted pipe Perimeter (ft) 

WATER HORSEPOWER = Flow (gpm) X Head (ft) 

3960 

BRAKE HORSEPOWER = Flow (gpm) X Head (ft) 

3960 X Pump Efficiency 

MOTOR HORSEPOWER = Flow (gpm) X Head (ft) 

3960 X Pump Eff. X Motor Eff. 

MEAN OR AVERAGE = Sum of the Values 

Number of Values 

TOTAL HEAD (ft) = Suction Lift (ft) X Discharge Head (ft) 

SURFACE LOADING RATE = Flow Rate (gpm) 

(gal/min/sq.ft) Surface Area (sq. ft) 

MIXTURE = (Volume 1, gal) (Strength 1, %) + (Volume 2, gal) (Strength 2,%) 

STRENGTH (%) (Volume 1, gal) + (Volume 2, gal) 

INJURY FREQUENCY RATE = (Number of Injuries) 1,000,000 

Number of hours worked per year 

DETENTION TIME (hrs) = Volume of Basin (gals) X 24 hrs 

Flow (GPD) 

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SLOPE = Rise (ft) SLOPE (%) = Rise (ft) X 100 

Run (ft) Run (ft) 

POPULATION EQUIVALENT (PE): 

1 PE = .17 Pounds of BOD per Day 

1 PE = .20 Pounds of Solids per Day 

1 PE = 100 Gallons per Day 

LEAKAGE (GPD/inch) = Leakage of Water per Day (GPD) 

Sewer Diameter (inch) 

CHLORINE DEMAND (mg/L) = Chlorine Dose (mg/L) – Chlorine Residual (mg/L) 

�Q = Allowable time for decrease in pressure from 3.5 PSU to 2.5 PSI 

�q = As below 

2 2 

�Q = (0.022) (d1 L1)/Q �q = [ 0.085] [(d1 L1)/(d1L1)] 

q 

Q = 2.0 cfm air loss 

� = .0030 cfm air loss per square foot of internal pipe surface 

� = Pipe diameter (inches) 

L = Pipe Length (feet) 

V = 1.486 R 2/3 S 1/2 

� 

V = Velocity (ft./sec.) 

� = Pipe Roughness 

R = Hydraulic Radius (ft) 

S= Slope (ft/ft) 

HYDRAULIC RADIUS (ft) = Flow Area (ft. 2) 

Wetted Perimeter (ft.) 

WIDTH OF TRENCH (ft) = Base (ft) + (2 Sides) X Depth (ft 2) 

Slope 

Professor Melissa explaining math formulas. 

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Scratch Paper 

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Volume in Cubic Feet 

Cube Formula 

V= (L) (W) (D) 

Volume= Length X Width X Depth 

Cylinder Formula 

V= (.785) (D 2 ) (d) 

Build it, Fill it and Dose it. 

1. Convert 10 cubic feet to gallons of water? 

There is 7.48 gallons in one cubic foot. 

2. A tank weighs 800 pounds, how many gallons are in the tank? 

3. Convert a flow rate of 953 gallons per minute to million gallons per day. 

There is 1440 minutes in a day. 

4. Convert a flow rate of 610 gallons per minute to millions of gallons per day. 

5. Convert a flow of 550 gallons per minute to gallons per second. 

6. Now, convert this number to liters per second. 

7. A tank is 6’ X 15’ x 7’ and can hold a maximum of ____________ gallons of water. 

V= (L) (W) (D) X 7.48 = 

8. A tank is 25’ X 75’ X 10’, what is the volume of water in gallons? 

V= (L) (W) (D) X 7.48 = 

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9. In Liters? 

V= (L) (W) (D) X 7.48 =_________ X 3.785 

10. A tank holds 67,320 gallons of water. The length is 60’ and the width is 15’. How deep is 

the tank? 

Gallons______ ÷ 7.48 = _______ 60 X 15 = 

11. The diameter of a tank is 60’ and the depth is 25’. How many gallons does it hold? 


V= (.785) (D 2 ) (d) 

.785 X 60’ X 60’ X 25’ X 7.48 = 

Cubic Feet Information 

There is no universally agreed symbol but the following are used: 

cubic feet, cubic foot, cubic ft 

cu ft, cu feet, cu foot 

ft 3 , feet 3 , foot 3 

feet 3 , foot 3 , ft 3 

feet/-3, foot/-3, ft/-3 

Water Treatment Production Math Numbering System 

In water treatment, we express our production numbers in Million Gallon numbers. Example 

2,000,000 or 2 million gallons would be expressed as 2 MG or 2 MGD. 

Hints. A million has six zeros; you can always divide your final number by 1,000,000 or move 

the decimal point to the left six places. Example 528,462 would be expressed .56 MGD. 

12. The diameter of a tank is 15 Centimeters or cm and the depth is 25 cm, what is the 

volume in liters? 

2.54cm = 1 inch, 12 inches = 1 foot 

15 cm ÷ 2.54 cm ÷ 12 inches = .492 feet 

.785 X .492’ X .492’ X _____’ =______ X 7.48 = _______ X 3.785 L = 

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Percentage and Fractions 

Let's look again at the sequence of numbers 1000, 100, 10, 1, and continue the pattern to get 

new terms by dividing previous terms by 10: 

.1 = 1/10 

.01 = 1/100 

.001 = 1/1000 

So just as the digits to the left of the decimal represent 1's, 10's, 100's, and so forth, digits to 

the right of the decimal point represent 1/10's, 1/100's, 1/1000's, and so forth. 

Let’s express 5% as a decimal. 5 ÷ 100 = 0.05 or you can move the decimal point to the left 

two places. 

Changing a fraction to a decimal: 

Divide the numerator by the denominator 

A. 5/10 (five tenths) = five divided by ten: 

.5 

----- 

10 ) 5.0 

5 0 

---- 

So 5/10 (five tenths) = .5 (five tenths). 

B. How about 1/2 (one half) or 1 divided by 2 ? 

.5 

----- 

2 ) 1.0 

1 0 

---- 

So 1/2 (one half) = .5 (five tenths) 

Notice that equivalent fractions convert to the same decimal representation. 

8/12 is a good example. 8 ÷ 12 =.66666666 or rounded off to .667 

How about 6/12 or 6 inches? .5 or half a foot 

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Flow and Velocity 

This depends on measuring the average velocity of flow and the cross-sectional area of the 

channel and calculating the flow from: 

Q(m 3 /s) = A(m 2 ) X V(m/s) 

Or 

Q = A X V 

Q CFM = Cubic Ft, Inches, Yards of time, Sec, Min, Hrs, Days 

A = Area, squared Length X Width 

V f/m = Inch, Ft, Yards, Per Time, Sec, Min, Ft or Speed 

13. A channel is 3 feet wide and has water flowing to a depth of 2.5 feet. If the velocity 

through the channel is 2 fps or feet per second, what is the cfs flow rate through the channel? 

Q = A X V 

Q = 7.5 sq. ft. X 2 fps What is Q? 

A= 3’ X 2.5’ = 7.5 

V= 2 fps 

14. A channel is 40 inches wide and has water flowing to a depth of 1.5 ft. If the velocity of 

the water is 2.3 fps, what is the cfs flow in the channel? Q = A X V 

First we must convert 40 inches to feet. 

40 ÷ 12” = 3.333 feet 

A = 3.333’ X 1.5’ = 4.999 or round up to 5 

V = 2.3 fps 

We can round this answer up. 

15. A channel is 3 feet wide and has a water flow at a velocity of 1.5 fps. If the flow through 

the channel is 8.1 cfs, what is the depth of the water? 

Q = 8.1 cfs 

V = 1.5 fps 

A = ? 

8.1 ÷1.5 = _______ Total Area 

16. The flow through a 6 inch diameter pipe is moving at a velocity of 3 ft/sec. What is the cfs 

flow rate through the pipeline? 

Q = 

A = .785 X .5’ X .5’ = 

V = 3 fps 

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17. An 8 inch diameter pipe has water flowing at a velocity of 3.4 fps. What is the gpm flow 

rate through the pipe? 

Q = ______ cfs X 60 sec/min X 7.48 = ___________ gpm 

A = .785 X .667’ X .667’ 

V = 3.4 fps 

18. A 6 inch diameter pipe delivers 280 gpm. What is the velocity of flow in the pipe in ft/sec? 

Take the water out of the pipe. 280 gpm ÷ 7.48 ÷ 60 sec/min = ________ cfs 

Q = 

A = .785 X .5’ X .5’ = 

V = 

19. A new section of 12 inch diameter pipe is to be disinfected before it is placed in service. If 

the length is 2000 feet, how many gallons of 5% NaOCl will be need for a dosage of 200 

mg/L? 


V= (.785) (D 2 ) (d) 

.785 X 1’ X 1’ X 2000’ = _______ cu.ft. X 7.48 = ______ ÷ 1,000,000 = ___________MG 

Pounds per day formula = Flow (MGD) X Dose (mg/L) X 8.34 lbs/gal if 100% concentrate. 

If not, divide the lbs/day by the given % 

0.0117436 MG X 200 mg/L X 8.34 =_________ lbs/day ÷ .05 = 

20. A section of 6 inch diameter pipe is to be filled with water. The length of the pipe is 1320 

feet long. How many kilograms of chlorine will be needed for a chlorine dose of 3 mg/L? 

.785 X .5’ X .5’ X 1320’ X 7.48 =_____________ Make it MGD 

Pounds per day formula = Flow X Dose X 8.34 X 45.4 Grams per pound 

21. Determine the chlorinator setting in pounds per 24 hour period to treat a flow of 3.4 MGD 

with a chlorine dose of 3.35 mg/L? 

Pounds per day formula = Flow (MGD) X Dose (mg/L) X 8.34 lbs/gal 

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22. To correct an odor problem, you use chlorine continuously at a dosage of 15 mg/L and a 

flow rate of 85 GPM. Approximately how much will odor control cost annually if chlorine is 

$0.17 per pound? 

85 gpm X 1440 min/day = _____________ gpd ÷ 1,000,000 = __________ MGD 

______ MGD X 15 mg/L X 8.34 lbs/gal X $0.17 per pound X 365 days/year = 

23. A wet well measures 8 feet by 10 feet and 3 feet in depth between the high and low levels. 

A pump empties the wet well between the high and low levels 9 times per hour, 24 hours a 

day. Neglecting inflow during the pumping cycle, calculate the flow into the pump station in 

millions of gallons per day (MGD). 

Build it, fill it and do what it says, hint: X 9 X 24 

24. A sewage treatment plant has a flow of 0.7 MGD and a BOD of 225 mg/L. On the basis of 

a national average of 0.2 lbs BOD per capita per day, what is the approximate population 

equivalent of the plant? 

25. What is the detention time of a clarifier with a 250,000 gallon capacity if it receives a flow 

of 3.0 MGD? 

DT= Volume in Gallons X 24 Divided by MGD 

.25 MG X 24 hrs. ÷ 3.0 MGD =________ Hours of DT 

Always convert gallons to MG 

Crazy Math Section 

The metric system is known for its simplicity. All units of measurement in the metric system are 

based on decimals—that is, units that increase or decrease by multiples of ten. A series of 

Greek decimal prefixes is used to express units of ten or greater; a similar series of Latin 

decimal prefixes is used to express fractions. For example, deca equals ten, hecto equals one 

hundred, kilo equals one thousand, mega equals one million, giga equals one billion, and tera 

equals one trillion. For units below one, deci equals one-tenth, centi equals one-hundredth, 

milli equals one-thousandth, micro equals one-millionth, nano equals one-billionth, and pico 

equals one-trillionth. 

26. How many grams equal 4,500 mg? 

Just simply divide by 1,000. 

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Temperature 

There are two main temperature scales. The Fahrenheit Scale (used in the US), and the 

Celsius Scale (part of the Metric System, used in most other Countries) 

They both measure the same thing (temperature!), just using different numbers. 

� If you freeze water, it measures 0° in Celsius, but 32° in Fahrenheit 

� If you boil water, it measures 100° in Celsius, but 212° in Fahrenheit 

� The difference between freezing and boiling is 100° in Celsius, but 180° in Fahrenheit. 

Conversion Method 

Looking at the diagram, notice: 

� The scales start at a different number (32 vs. 0), so we will need to add or subtract 32 

� The scales rise at a different rate (180 vs. 100), so we will also need to multiply 

And this is how it works out: 

To convert from Celsius to Fahrenheit, first multiply by 180/100, then add 32 

To convert from Fahrenheit to Celsius, first subtract 32, then multiply by 100/180 

Note: 180/100 can be simplified to 9/5, and likewise 100/180=5/9. 

0 F = ( 0 C X 9/5) + 32 9/5 =1.8 

0 C = ( 0 F - 32) X 5/9 5/9 = .555 

27. Convert 20 degrees Celsius to degrees Fahrenheit. 

20 o X 1.8 + 32 = F 

28. Convert 4 degrees Celsius to degrees Fahrenheit. 

4 o X 1.8 + 32 = F 

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Water Treatment Filters 

29. A 19 foot wide by 31 foot long rapid sand filter treats a flow of 2,050 gallons per minute. 

Calculate the filtration rate in gallons per minute per square foot of filter area. 

GPM ÷ Square Feet 

30. A 26 foot wide by 36 foot wide long rapid sand filter treats a flow of 2,500 gallons per 

minute. Calculate the filtration rate in gallons per minute per square foot of filter area. 

Chemical Dose 

31. A pond has a surface area of 51,500 square feet and the desired dose of a chemical is 6.5 

lbs per acre. How many pounds of the chemical will be needed? 

43,560 Square feet in an acre 

51,500 ÷ 43,560 = _______ X 6.5 = 

32. A pond having a volume of 6.85 acre feet equals how many millions of gallons? 

33. Alum is added in a treatment plant process at a concentration of 10.5 mg/L. What should 

the setting on the feeder be in pounds per day if the plant is treating 3.5 MGD? 


Q=AV Review 

34. An 8 inch diameter pipe has water flowing at a velocity of 3.4 fps. What is the GPM flow 

rate through the pipe? 

Q = 1.18 CFS x 60 Seconds x 7.48 GAL/CU.FT = 532 GPM 

A = .785 X .667 X .667 X 1 = .349 Sq. Ft. 

V= 3.4 Feet per second 

35. A 6 inch diameter pipe delivers 280 GPM. What is the velocity of flow in the pipe in 

Ft/Sec? 

280 GPM ÷ 60 seconds in a minute ÷ 7.48 gallons in a cu.ft. = .623 CFS 

Q = .623 

A = .785 X.5 X .5 =.196 Sq. Ft. 

V = 3.17 Ft/Second 

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Collections 

36. A 24-inch sewer carries an average daily flow of 5 MGD. If the average daily flow per 

person from the area served is 110 GPCD (gallons per capita per day), approximately how 

many people discharge into the wastewater collection system? 

5,000,000 divided by 110 = 

37. Using a dose rate of 5 mg/L, how many pounds of chlorine per day should be used if the 

flow rate is 1.2 MGD? 


38. What capacity blower will be required to ventilate a manhole which is 3.5 feet in diameter 

and 17 feet deep? The air exchange rate is 16 air changes per hour. 

.785 X 3.5’ X 3.5’ X 17’ X 16 = ____________ CFH 

39. Approximately how many feet of drop are in 455 feet of 8-inch sewer with a 0.0475 ft/ft. 

slope? 



455’ X 0.0475 = 

40. How much brake horsepower is required to meet the following conditions: 250 gpm, total 

head = 110 feet? The submersible pump that is being specified is a combined 64% efficient. 

(250 X 110) ÷ (3960 X .64) 

41. How wide is a trench at ground surface if a sewer trench is 2 feet wide at the bottom, 10 

feet deep and the sides have been sloped at a 4/5 horizontal to 1 vertical (3/4:1) ratio? 

(3/4:1) or 3 ÷ 4 = .75 X every foot of depth 

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42. A float arrives in a manhole 550 feet down stream three minutes and thirty seconds from 

its release point. What is the velocity in ft/sec.? 

Velocity ft/sec = distance ÷ time 

550’ ÷ 3 min stop convert min to sec. 3 X 60 = 180 + 30 = 210 sec 

550’ ÷ 210 sec = ______ fps 

43. A new sewer line plan calls out a 0.6% slope of the line. An elevation reading of 108.8 feet 

at the manhole discharge and an elevation of 106.2 feet at a distance of 200 feet from the 

manhole are recorded. What is the existing slope of the line that has been installed? 



44. A triangular pile of spoil is 12 feet high and 14 feet wide at the base. The pile is 75' long. If 

the dump truck hauls 9 cubic yards of dirt, how many truck loads will it take to remove all of the 

spoil? 

Given the base and the height of a triangle, we can find the area. Given the area and either the 

base or the height of a triangle, we can find the other dimension. The formula for area of a triangle 

is: 

Or where is the base, is the height. 

14’ X 12’ ÷ 2 X 75’ = _________ cuft (27cuft/cuyrd) 

45. A red dye is poured into an upstream manhole connected to a 12 inch sewer. The dye first 

appears in a manhole 400 feet downstream 3 minutes later. After 3 minutes and 40 seconds 

the dye disappears. Estimate the flow velocity in feet per second? 

Velocity ft/sec = distance ÷ time 

Make sure and convert time and average it. 

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46. Calculate the total dosage in pounds of a chemical. Assume the sewer is completely filled 

with the concentration. Pipe diameter: 18 inches, Pipe length: 420 feet, Dose: 120 mg/L. 

Figure out the volume first. 

.785 X 1.5’ X 1.5’ X 420’ X 7.48 =___________ convert to MG 


Answers 

1. 7.48 X 10 = 74.8 

2. 800 ÷ 8.34 = 95.92 gallons 

3. 1372320 or 1.3 MGD 

4. 610 X 1441 = 878400 or 0.87 MGD 

5. 550 ÷ 60 = 9.167 gpm 

6. 9.167 X 3.785 = 34.695 Liters 

7. 630 Area 4712 gallons 

8. 18,750 cu. ft. X 7.48 = 140250 

gallons 

9. 140250 X 3.785 = 530846 Liters 

10. 10 feet deep 

11. 528462 or .5 MG 

12. 1.166 Gallons X 3.785 = 4.412 

Liters 

13. 15 cfs 

14. 11.49 cfs 

15. 1.8’ 

16. .58875 cfs 

17. 533 gpm 

18. 3.2 ft/sec 

19. 46.9 gal 

20. .002 kg 

21. 94.9 lbs/day 

22. $950.12 

23. .387 MG 

24. 6567.75 

25. 2 hrs 

26. 4.5 grams 

27. 68° F 

28. 39°F 

29. 3.48 gpm/sqft 

30. 2.67 gpm/sqft 

31. 7.68 lbs 

32. 2.231 MG 

33. 306.495 

34. 532 gpm 

35. 3.2 fps 

36. 45454.5 people 

37. 50.04 lbs 

38. 2615.6 cfh 

39. 21.61 ft 

40. 10.85 bhp 

41. 17 ft 

42. 2.62 fps 

43. .013 or 1.3% 

44. 26 trucks 

45. 2 fps 

46. 5.55 lbs 

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Scratch Paper 

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References 

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ATS [1987]. Standardization of spirometry -- 1987 update. American Thoracic Society. Am Rev Respir Dis 

Basic Principles of Water Treatment, Littleton, Colorado. Tall Oaks Publishing Inc. 

Bick, H. 1972. Ciliated protozoa. An illustrated guide to the species used as biological indicators in freshwater 

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Born, Stephen M., Douglas A. Yanggen, and Alexander Zaporozec. A Guide to Groundwater Quality Planning and 

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39:405-427. 

Cairns, J., and W.H. Yongue. 1977. Factors affecting the number of species of freshwater protozoan communities. 

Pages 257-303 in J. Cairns, ed. Aquatic microbial communities. Garland, New York. 

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communities with emphasis on freshwater algae and protozoa. Proceedings of the National Academy of Sciences 

124:79-127. 

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Cross, Brad L and Jack Schulze. City of Hurst (A Public Water Supply Protection Strategy). Texas Water 

Commission, Austin, TX, 1989. 

Curds, C.R. 1992. Protozoa and the water industry. Cambridge University Press, MA. 122 pp. 

Curtis, Christopher and Teri Anderson. A Guidebook for Organizing a Community Collection Event: Household 

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Management, West Springfield, MA, 1984. 

Curtis, Christopher, Christopher Walsh, and Michael Przybyla. The Road Salt Management Handbook: Introducing a 

Reliable Strategy to Safeguard People & Water Resources. Pioneer Valley Planning Commission, West Springfield, 

MA, 1986. 

DOT [1993]. 1993 Emergency response guidebook, guide 20. Washington, DC: U.S. Department of Transportation, 

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Fenchel, T. 1974. Intrinsic rate increase: the relationship with body size. Oecologia 14:317-326. 

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testaceans, bioindicators, and guide to the literature. Progress in Protistology 2:69-212. 

Foissner, W. 1988. Taxonomic and nomenclatural revision of Stádecek's list of ciliates (Protozoa: Ciliophora) as 

indicators of water quality. Hydrobiologia 166:1-64. 

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Genium [1992]. Material safety data sheet No. 53. Schenectady, NY: Genium Publishing Corporation. 

Giese, A.C. 1973. Blepharisma. Stanford University Press, CA. 366 pp. 

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NY 1984. 

Grant WM [1986]. Toxicology of the eye. 3rd ed. Springfield, IL: Charles C Thomas. 

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Protection for Local Officials. Connecticut Department of Environmental Protection, Hartford, CT, 1984. 

Hathaway GJ, Proctor NH, Hughes JP, and Fischman ML [1991]. Proctor and Hughes' chemical hazards of the 

workplace. 3rd ed. New York, NY: Van Nostrand Reinhold. 

Hrezo, Margaret and Pat Nickinson. Protecting Virginia's Groundwater A Handbook for Local Government Officials. 

Virginia Polytechnic Institute and State University, Blacksburg, VA, 1986. 

Jaffe, Martin and Frank Dinovo. Local Groundwater Protection. American Planning Association, Chicago, IL, 1987. 

Kreier, J.P., and J.R. Baker. 1987. Parasitic protozoa. Allen and Unwin, Boston, MA. 241 pp. 

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Laybourn, J., and B.J. Finlay. 1976. Respiratory energy losses related to cell weight and temperature in ciliated 

protozoa. Oecologia 44:165-174. 

Lee, C.C., and T. Fenchel. 1972. Studies on ciliates associated with sea ice from Antarctica. II. Temperature 

responses and tolerances in ciliates from Antarctica, temperate and tropical habitats. Archive für Protistenkunde 

114:237-244. 

Lewis RJ, ed. [1993]. Lewis condensed chemical dictionary. 12th ed. New York, NY: Van Nostrand Reinhold 

Company. 

Lide DR [1993]. CRC handbook of chemistry and physics. 73rd ed. Boca Raton, FL: CRC Press, Inc. 

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Island, Providence, RI, 1988. 

Macozzi, Maureen. Groundwater- Protecting Wisconsin's Buried Treasure. Wisconsin Department of Natural 

Resources, Madison, WI, 1989. 

Maine Association of Conservation Commissions. Ground Water... Maine's Hidden Resource. Hallowell, ME, 1985. 

Massachusetts Audubon Society "Local Authority for Groundwater Protection." Groundwater Information Flyer #4. 

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Massachusetts Audubon Society. "Groundwater and Contamination: From the Watershed into the Well." 

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Massachusetts Audubon Society. "Road Salt and Groundwater Protection." Groundwater Information Flyer # 9. 


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Mickelsen RL, Hall RC [1987]. A breakthrough time comparison of nitrile and neoprene glove materials produced by 

different glove manufacturers. Am Ind Hyg Assoc J 941-947 

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permeation of organic liquids through rubber films. Am Ind Hyg Assoc J 445-447 

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Montagnes, D.J.S., D.H. Lynn, J.C. Roff, and W.D. Taylor. 1988. The annual cycle of heterotrophic planktonic ciliates 

in the waters surrounding the Isles of Shoals, Gulf of Maine: an assessment of their trophic role. Marine Biology 

99:21-30. 

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National Research Council. Ground Water Quality Protection: State and Local Strategies. National Academy Press, 

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MA, 1989. 

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effects from multispecies microcosm toxicity test. Archives of Environmental Contamination and Toxicology 19:62-71. 

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statements. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for 

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Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, 

DHHS (NIOSH) Publication No. 94-113. 

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and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety 

and Health, Division of Standards Development and Technology Transfer, Technical Information Branch. 

NJDH [1992]. Hazardous substance fact sheet: Chlorine. Trenton, NJ: New Jersey Department of Health. 

NLM [1995]. Hazardous substances data bank: Chlorine. Bethesda, MD: National Library of Medicine. 

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Environmental Quality Engineering, Boston, MA, 1988. 

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Office of Ground-Water Protection. Guidelines for Delineation of Wellhead Protection Areas. U.S. EPA, Washington, 

D.C., 1987. 

Office of Ground-Water Protection. Survey of State Ground Water Quality Protection Legislation Enacted From 1985 

Through 1987. U.S. EPA, Washington, D.C., 1988. 

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Washington, D.C., 1989. 

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1987 

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Storage Tank Systems. U.S. EPA, Washington, D.C., 1988. 

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It Clean." Tucson, AZ. 

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Water Treatment, Second Edition 

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Water Treatment Summary Exercise (Review) 

This is not your final assignment. This is a review of the water treatment material. 

Answers are in the rear of this section. 

The Hydrologic Cycle 

The water on the planet today is the same water that has been on the planet since the 

beginning. The water that you drank today most likely has been drunk before many years ago. 

The planet never gets any new water, instead the water cycles from one place to another. 

As the water cycles, it goes through many processes. These processes are nature’s way of 

purifying the water. 

Give a brief definition of the listed components of the water cycle. 

1. Precipitation: 

2. Runoff: 

3. Infiltration: 

4. Percolation: 

5. Evaporation: 

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6. Another term used for plants giving off moisture would be: 

A. Condensation 

B. Precipitation 

C. Percolation 

D. Transpiration 

7. There are three basic types of water rights, they are: 

Source of Water 

When you go see your doctor due to illness, they need to know the source of your problem so 

they can properly treat it. The same is true when treating water. The hydrological cycle shows 

several attributes of the earth purifying and moving water. To simplify this, we will focus on two 

categories of source water, Ground Water and Surface Water. 

8. A porous material just above the water table describes this source to be surface water. 

A. True 

B. False 

9. As water moves over or below the earth surface the quality of the water is classified as the 

following EXCEPT for: 

A. Physical 

B. Biological 

C. Chemical 

D. Radiological 

E. Evolutional 

10. In the space provided below, list the physical characteristics of water. 

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Managing Water Quality at the Source 

11. In this lesson, you will focus on surface water and the different factors that affect the quality 

of the water. Many populations have depended on lakes as a source of impounded domestic 

water supplies. As the population increases, list below brief examples of how the supplies 

are being used? 

12. Several common water quality problems in domestic water supply reservoirs may be related 

to algae blooms. Which of the following summarizes the problems that can occur? 

A. Taste and odor problems 

B. Short filter runs at the plant do to clogging 

C. Increased pH 

D. Dissolved oxygen depletion 

E. All of the above 

Define the following terms: 

13. Anaerobic: 

14. Aerobic: 

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15. During the winter months, which condition is most likely to occur do to cold water conditions 

on the bottom of the lake? 

A. Anaerobic 

B. Aerobic 

16. The presence of hydrogen sulfide will produce which type of odor? 

A. Earthy 

B. Fishy 

C. Rotten egg 

D. Roses 

17. What is the definition for Oxidation? 

18. What does MCL stand for? 

A. Maximum Containment Level 

B. Minimum Contaminant Level 

C. Maximum Can-drink Level 

D. Maximum Contaminant Level 

19. In which Federal Act would you find the MCL for drinking water? 

A. SDWA 

B. OSHA 

C. NEPDES 

D. CWA 

20. Lakes and reservoirs have intake-outlet structures. In the space provided below, list types 

of structures and/or screens. 

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Coagulation and Flocculation 

21. Surface water for domestic use will have some form of impurities. It can be in the form of 

INORGANIC materials or ORGANIC materials. Given the following illustrations, determine if 

they are Inorganic or Organic. 

A. Salt is ____ 

B. Oxygen is ____ 

C. Dirt is ____ 

D. Tree leaves are ____ 

22. Which statement describes COLLOIDAL matter? 

A. Solids that sink to the bottom of a lake 

B. Solids that are invisible 

C. Solids that float to the top 

D. Solids that are very small and repel each other 

23. The purpose of using the Coagulation and Flocculation process is to remove the particulate 

impurities in the water. Which of the two would you use the addition of chemicals? 

A. Coagulation 

B. Flocculation 

24. What is the purpose of flash mixing? 

A. Using lightning to shock the water 

B. To mix the chemical slowly 

C. To mix the chemical in the water rapidly to prevent clumps 

D. None of the above 

25. List four primary coagulants used in water treatment. 

A. 

B. 

C. 

D. 

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26. Which type of laboratory analysis best simulates the plant process to determine the 

coagulant dosage? 

A. Temperature 

B. pH 

C. Turbidity 

D. Jar Test 

E. Alkalinity 

27. Flocculation and Flash Mixing are the same process. 

A. True 

B. False 

28. Flocculation is a slow stirring process that causes the gathering together of small, 

coagulated particles into larger, settleable floc particles. 

A. True 

B. False 

29. What is the advantage of minimizing chemical coagulant doses? 

A. Less sludge is produced and chemical cost are reduced 

B. Shorter settling times 

C. Shorter filter runs 

D. Big clumps floating to the top 

30. What is short-circuiting? 

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Sedimentation 

We used the term PRECIPITATION in the hydrological cycle. It gives us a fancy word for RAIN. 

A cloud forms and rain begins to FALL towards the earth. The same happens to the impurities 

we coagulated and flocculated. The impurities precipitate and settle to the bottom. This is done 

in SEDIMENTATION basins. 

31. Depending on the quality of the source water, some plants have PRE-Sedimentation. Give 

two reasons for this. 

A. 

B. 

32. List some sedimentation basin components. 

A. 

B. 

C. 

D. 

33. List possible shapes for a sedimentation basin. 

A. 

B. 

C. 

34. What is the definition for Detention Time? 

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35. If a sedimentation basin sludge depth increases, what will happen to the detention time? 

A. It will remain the same 

B. It will increase 

C. It will decrease 

D. None of the above 

36. What does frequent clogging of the sludge discharge line indicate? 

A. Failure to properly maintain the sludge discharge line 

B. Sludge concentration is too low 

C. Sludge concentration is too high 

D. This stuff belongs at the wastewater plant 

Filtration 

Filtration is the last attempt in removing particulate impurities from the water. In the treatment 

plant we use a mechanical straining for removal; like a coffee filter that keeps the grounds out of 

the pot. There are two classifications of filtration plants: Direct filtration and Conventional. 

37. What is the major difference between a Direct Filtration Plant and a Conventional Plant? 

38. The filtration process removes which type of particles? 

A. Silts and clay 

B. Colloids 

C. Biological forms 

D. Floc 


39. List four desirable characteristics of filter media. 

A. 

B. 

C. 

D. 

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40. Evaluation of overall filtration process performance should be conducted on a routine basis, 

at least once per day. 

A. True 

B. False 

41. Poor chemical treatment can often result in either early turbidity breakthrough or rapid head 

loss buildup. 

A. True 

B. False 

42. The more uniform the media, the faster the head loss buildup. 

A. True 

B. False 

43. How are filter production rates measured? 

A. GPM 

B. GPM/sq ft 

C. MGD 

D. MGD/sq ft 

44. Filter media provides several characteristics. List three types: 

A. 

B. 

C. 

45. Give a brief description of a DECLINING-RATE filter. 

46. What does S.W.T.R. stand for? 

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Disinfection 

47. Which of the following pathogens are waterborne diseases? 

A. Shingella 

B. Hepatitis B 

C. Giardia lamblia 

D. Both A & C 

E. None of the above 

48. List three benefits of prechlorination. 

A. 

B. 

C. 

49. What does organic matter form when it reacts with chlorine? 

A. Floc 

B. Nitrates 

C. THM's 

D. Turbidity 

50. When the temperature increases, the pressure of the chlorine gas inside a chlorine 

container will decrease. 

A. True 

B. False 

51. Hypochlorite compounds tend to lower the pH of the water being disinfected. 

A. True 

B. False 

52. Moisture in a chlorination system will combine with the chlorine gas and cause corrosion. 

A. True 

B. False 

53. You can use regular pipe fittings when making connections with chlorine containers. 

A. True 

B. False 

54. Always work in pairs when looking and repairing chlorine leaks. 

A. True 

B. False 

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55. When a chlorine leak exist, use water to dilute it. 

A. True 

B. False 

56. How do water temperature conditions influence the effectiveness of chlorine as a 

disinfectant? 

A. The lower the water temperature the easier to disinfect the water 

B. The warmer the water the less dissipation rate of chlorine to the atmosphere 

C. The higher the temperature the easier to disinfect the water 

D. The warmer the water, the longer contact time needed 

57. Which of the following chemical must be present for a breakpoint chlorination curve to 

develop when chlorine is added to water? 

A. Iron 

B. Ammonia 

C. Manganese 

D. Organic matter 

58. What does the product of C x T provide a measure of? 

A. Level of disinfectant intensity 

B. Rate of chloramine formation 

C. Degree of pathogenic inactivation 

D. Threat of THM formation 

59. What formula would you use to calculate the chlorine feed in pounds per day? 

60. List eight parts that are used for a chlorinator. 

A. 

B. 

C. 

D. 

E. 

F. 

G. 

H. 

61. Give a brief description for the use of a fusible plug in a steel cylinder. 

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62. What is the maximum rate of chlorine removal in a 150 pound cylinder? 

63. What is the most probable cause of leaking joints in gas chlorinator systems? 

A. Acid corrosion of joints 

B. Back pressure 

C. Gas pressure to high 

D. Missing gasket 

64. How are probes used in the disinfection process? 

A. They accurately measure chlorine dosage 

B. They measure the liquid chlorine remaining in a chlorine container 

C. They provide a direct measure of the disinfecting power of the disinfectant 

D. They quickly measure and record chlorine residual 


65. Which of the following factors influence chlorine disinfection? 

A. Microorganisms 

B. pH 

C. Reducing agents 

D. Temperature 

E. All the above 

66. Why will the engines of emergency vehicles quit operating in the vicinity of a large 

chlorine leak? 

A. Corrosion damage from chlorine 

B. Crowds of rubber necks 

C. Lack of oxygen 

D. To far gone to look back and see why 

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Exercise Answers 

1. When atmospheric moisture falls on land or surface water as rain, snow, hail, or another 

form of moisture. 

2. Water draining from an impermeable or saturated surface into stream channels and/or 

other surface waters, such as rivers or lakes. 

3. Gradual flow of water through porous materials, such as soil. 

4. Flow of water through coffee, tea, etc. to create a beverage. 

5. Process by which liquids (water, gasoline, etc.) become a gas. 

15. Transpiration 

7. Appropriative: Acquired water rights for exclusive use 

Prescriptive: Rights based upon legal prescription or long use or custom 

Riparian: Water rights because property is adjacent to a river or other surface water. 

8. False (199) (ground water) 

9. Evolutional (40 & 201) 

10. Water is a solid below 32 degrees Fahrenheit 

Water is liquid between 32 degrees Fahrenheit and 212 degrees Fahrenheit Water is in a 

gaseous state above 212 degrees Fahrenheit. Other Physical Characteristics: Turbidity, 

Color, Temperature, Tastes, and Odors. 

11. Surface water supplies (lakes, rivers, etc.) are being used for recreational purposes 

(boating, swimming, etc.), domestic purposes (drinking, cooking, bathing, cleaning, etc.) 

and agricultural purposes (irrigation). 

12. All of the above 

13. Anaerobic conditions occur when there is an absence of oxygen. Without sunlight, algae 

consumes oxygen and releases carbon dioxide, thus removing oxygen from water. When 

there is an absence of oxygen in water, color and odor problems are likely to occur. 

Dissolved oxygen can be added to water to combat anaerobic conditions. 

14. Aerobic conditions occur when there is a presence of oxygen. When algae absorbs 

energy from the sun, it converts carbon dioxide to oxygen (photosynthesis), thus adding 

dissolved oxygen to water. Significant levels of dissolved oxygen in water allows iron and 

manganese to exist in an oxidized state, which causes these metals to precipitate downward, 

thus improving water color and odor. 

15. Anaerobic Destratification) 

16. Rotten egg 

17. (Add Oxygen; Remove Hydrogen/Electrons) 

Oxidation originally meant a reaction in which oxygen combines chemically with another 

substance, but now it includes any reaction in which electrons are transferred. Oxidation 

occurs simultaneously with Reduction (Redox Reactions). The substance which gains 

electrons is the oxidizing agent 

18. Maximum Contaminant Level 

19. SDWA (31) (V1; P31) 

20. 1. Bar Screens: 

Mechanical – Vary in size and bar spacing. Have raking mechanisms that scrape off 

debris. 

Non-Automated – have to be manually cleaned. 

2. Wire Mesh Screens: 

Made of woven stainless steel, vee-wire, and slotted plates 

Usually have narrow openings, Usually manually cleaned 

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21. 

A. Salt is _Inorganic 

B. Oxygen is _Inorganic 

C. Dirt is _Inorganic and Organic 

D. Tree leaves are Organic Inorganic – No Carbons Organic – Carbons 

22. Solids that are very small and repel each other 

23. Coagulation 

24. None of the above 

25. A. Aluminum Sulfate (Alum): neutralizes particles’ negative charge; use when pH is 5.0 

to 7.5 

B. Ferric Chloride: neutralizes particles’ negative charge; use when pH is less than 4.5 

C. Ferrous Sulfate: neutralizes particles’ negative charge; use when pH is 4.5 to 9.5 D. 

Cationic Polymers: positively charged strings that attract particles to from larger particles. 

Other proprietary coagulants are used in proprietary systems. 

26. Jar Test 

27. False (are not) 

28. True 

29. Less sludge is produced and chemical cost are reduced 

30. A condition that occurs when some water in a tank or basin flows faster than the rest of 

the flowing water. This is usually undesirable because it may result in shorter contact, 

reaction, and/or settling times when compared with presumed or calculated detention times. 

31. A. It allows larger particles (sand, heavy silt, etc.) time to settle in a reservoir or lake, 

thus reducing solid removal loads. 

B. It provides an equalization basin, which evens out fluctuations in concentrations of 

suspended solids (Flow Equalization). 

32. A. Inlet Zone 

B. Settling Zone 

C. Sludge Zone 

D. Outlet Zone 

33. A. Rectangular Basins 

B. Circular Basins 

C. Square Basins 

34. The actual time required for a small amount of water to pass through a sedimentation 

basin at a given rate of flow, or the calculated time required for a small amount of liquid to 

pass through a tank at a given rate of flow. 

(Detention Time) = ((Volume in Gallons) * (24 Hrs per Day)) / (Flow in Gallons per Day) 

35. It will decrease (Volume in numerator decreases) 

(DT) = ((Vol in Gals)*(24 hrs/day)) / (Flow in Gals/Day) 

36. Failure to properly maintain the sludge discharge line 

37. The sedimentation process or step is omitted from the Direct Filtration Plant. 

38. Silts and clay 

39. Permeable (good hydraulic characteristics)B. Inert and easy to clean (doesn’t react with 

substances in water)C. Hard and durableD. Free of impurities and insoluble in water 

40. True 

41. True 

42. False (slower) 

43. GPM/sq ft 

44. A. Permeable (good hydraulic characteristics)B. Hard and durable C. Free of impurities 

and insoluble in water Also inert and easy to clean (non-reactive with water substances) 

WT303� 10/13/2011 TLC 518 

(866) 557-1746 Fax (928) 468-0675

45. The rate of flow varies with head loss. Each filter operates at the same rate but can have 

a variable water level. This system requires a weir (effluent control structure) to provide 

adequate submergence. 

46. Surface Water Treatment Rule 

47. Shingella & Giardia lamblia 

48. A. Control algae and slime growth B. Control mudball formation C. Improve coagulation 

49. THM's 

50. False (85, 98, 105, 187) (increase) 

51. False (116) (V1; P268-269) (Raise) 

52. True (85, 92) (V1; P303-304) 

53. False (92, 108) (V1; P295) (cannot) 

54. True (V1; P304 & 312) 

55. False (Volume 1; Page 314) (do not use) 

56. (105) (V1; P263) 

57. ALL; 

58. (Volume 1; Page 273) 

E. Level of disinfectant intensity 

F. Rate of chloramine formation 

G. Degree of pathogenic inactivation 

H. Threat of THM formation 

59. (211) (V1; P275) 

(Chemical Feed in Lbs/Day) = (Flow in MGD) * (Dose in mg/l) * (8.34 Lbs/Gal) 

(Lbs/Day) = (Million Gallons/Day) * (Parts/Million) * (8.34 Gals/Day) 

60. List eight parts that are used for a chlorinator. 

A. Ejector 

B. Check Valve Assembly 

C. Rate Valve 

D. Diaphragm Assembly 

E. Interconnection Manifold 

F. Rotometer Tube and Float 

G. Pressure Gauge 

H. Gas Supply 

61. This metal plug will melt at 158 degrees Fahrenheit to 165 degrees Fahrenheit in order 

to prevent—buildup of excessive pressure—and the possibility of cylinder rupture—due to 

high temperatures. 

62. (40 Lbs/Day) * (1 Day/24Hrs) = (1.67 Lbs/Day) 

63. Missing or damaged gasket 

64. They quickly measure and record chlorine residual 

65. All the above 

66. Lack of oxygen 

WT303� 10/13/2011 TLC 519 

(866) 557-1746 Fax (928) 468-0675

We welcome you to complete the assignment in Microsoft Word. You can easily find 

the assignment at www.abctlc.com. Once complete, just simply fax or e-mail the 

answer key along with the registration page to us and allow two weeks for grading. 

Once we grade it, we will mail a certificate of completion to you. Call us if you need 

any help. If you need your certificate back within 48 hours, you may be asked to pay 

a rush service fee of $50.00. 

You can download the assignment in Microsoft Word from TLC’s website under the 

Assignment Page. www.abctlc.com You will have 90 days in order to successfully 

complete this assignment with a score of 70% or better. If you need any assistance, 

please contact TLC’s Student Services. Once you are finished, please mail, e-mail or 

fax your answer sheet along with your registration form. 

WT303� 10/13/2011 TLC 520 

(866) 557-1746 Fax (928) 468-0675

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