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Student Workbook

W ATER TRANSMISSION

AND DISTRIBUTION

Principles and Practices of Water Supply Operations


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Water Transmission

and Distribution

Student Workbook


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Printed in the United States of America

American Water Works Association6666 West Quincy AvenueDenver, CO 80235

303.794.7711

Water Transmission and Distribution Student WorkbookPrinciples and Practices of Water Supply Operations Series

Copyright © 2006, 2010 American Water Works Association.

All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means,

electronic or mechanical, including photocopy, recording, or any information or retrieval system, except in theform of brief excerpts or quotations for review purposes, without the written permission of the publisher.

Disclaimer

The authors, contributors, editors, and publisher do not assume responsibility for the validity of the content orany consequences of their use. In no event will AWWA be liable for direct, indirect, special, incidental, or con-

sequential damages arising out of the use of information presented in this book. In particular, AWWA will notbe responsible for any costs, including, but not limited to, those incurred as a result of lost revenue. In noevent shall AWWA’s liability exceed the amount paid for the purchase of this book.

Technical Editor Nancy McTigue

Project Manager: Melissa ValentineProduction: TIPS Technical Publishing, Inc.

Cover Design: Cheryl Armstrong

ISBN 10: 1-58321-800-9

ISBN 13: 978-1-58321-800-6


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Water Transmission

and DistributionStudent Workbook

Principles and Practices

of Water Supply Operations Series


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v

Contents

Contents v

Foreword vii

Acknowledgments ix

Introduction: Using Your Student Workbook xi

Chapter 1 Introduction to Water Distribution Systems 1

Chapter 2 Pipe Systems and Piping 7

Chapter 3 Water Storage 15

Chapter 4 Pumping Stations and Pumps 21

Chapter 5 Hydraulics of Water Distribution Systems 29

Chapter 6 Valves 35

Chapter 7 Fire Hydrants 41

Chapter 8 Motors and Engines 49

Chapter 9 Instrumentation and Control 57

Chapter 10 Water Meters 63

Chapter 11 Backflow Prevention and Cross-Connection Control 69

Chapter 12 Water Main Installation 75

Chapter 13 Backfilling, Main Testing, and Installation Safety 81

Chapter 14 System Operations 87

Chapter 15 Water Services 95

Chapter 16 Information Management 101

Chapter 17 System Security and Emergency Response 107

Chapter 18 Public Relations 115


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vii

Foreword

This workbook is designed for use with the text Water Transmission and Distribution in

the series Principles and Practices of Water Supply Operations, fourth edition. This edi-tion provides detailed information on the technology and information of commonly used

practices for potable water treatment.

Other volumes in the series are

Water Sources

• Water Treatment

• Water Quality

• Basic Science Concepts and Applications

The workbook provides assignments, review questions, and a convenient method for

keeping organized notes of important points as the text is reviewed. It is designed for use

in either classroom or independent study. Basic Science Concepts and Applications is a reference handbook that is a companion

to all the other text books. It contains basic reviews of mathematics, hydraulics, chemistry,

and electricity fundamental to water utility operation, as well as explanations and exam-

ples of many specific water system operating problems.

A special thanks to Nancy McTigue for the revision of this workbook.


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ix

Acknowledgments

The student workbooks have been added to the WSO series in conjunction with the fourth

edition updating of the WSO texts. The author of this Student Workbook is NancyMcTigue. Special thanks to Larry Mays, author of the revision of the text book, and Bill

Lauer, AWWA Senior Technical Manager, for their review of this workbook.


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xi

Introduction: Using Your Student Workbook

This Student Workbook is provided to assist you in studying the basic principles of water

distribution systems. If you carefully maintain your own personal workbook with notesand supplemental information, you will likely reference it throughout your water utility

career.

FORMAT

This workbook provides the following sections for each chapter of the text:

• Objectives. This is a listing of some of the major concepts that you should be able

to identify and explain when you have completed study of the chapter. You

should preview the list at the beginning of study to assess what will be covered.

You should then review it again when you have completed study of the chapter tosee if you adequately understand the listed concepts.

• Reading Assignments. A list is provided indicating the chapters and sections from

Water Transmission and Distribution and other texts that should be read in con-

junction with the study of the chapter.

• Other Assignments. If you are attending a class, this space can be used to make a

record of additional reading and study assignments made by the instructor. If you

are using this workbook for self-study, you can make notes for future reference

on additional sources of information.

• Class Notes. Space has been provided for you to keep notes of points you feel

are important as you read the text or of points made by the instructor during

class discussions.

• Review Questions. The review questions are intended to emphasize some of the

important concepts in the chapter.

• Study Problems. A few problems are provided to be used for additional study.

• Additional Notes. Each chapter concludes with an extra page for note taking.

TEXTS AND REFERENCES

It will be necessary for you to have copies of both Water Transmission and Distribution

and Basic Science Concepts and Applications available while studying the subject. You

should also have access to the other volumes in the series Principles and Practices of WaterSupply Operations because there are some references to them in the reading assignments.

If the copies you are using belong to your water utility or someone else, it is best not to

mark or highlight in the books. Your notes on important points can instead be made in the

workbook.

A list of supplementary sources of information is provided at the end of each chapter

in the text. You should try to make use of some of them, particularly if you have a special

interest in certain subjects. For example, if you are presently working at a water treatment


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xii WSO: Water Transmission and Distribution Student Workbook

facility, you will probably want to know more about the particular types of treatment or operating problems

experienced by your utility.

The supplementary reading list is, of course, current only as of the publication of the text. Many addi-

tional handbooks, manuals, and articles are published yearly. If you have a special interest in obtaining the

latest information on a subject, you may contact the American Water Works Association (AWWA) and some

of the other publishers and information sources for their current publications list. If you have access to a file

of back issues of the Journal AWWA and Opflow, you will find that an index of all articles for the previous

year is listed in each December issue. The “Water Library” section of the www.awwa.org website also has a

searchable database of Journal of the American Water Works Association and Opflow articles, conference

proceedings and AWWA Standards.

If you are presently working for a water utility, you probably have access to old editions and copies of

some texts that are no longer in print. You will find it is helpful to look through these books and read about

subjects you are studying, using this workbook. Sometimes, there may be more detail, or subjects may be

presented in a different way in another text. You must be aware, though, that water treatment technology and

state and federal regulations have changed greatly in recent years, so some information in an older text will

no longer be valid.

The principal publications that are frequently referenced and will be particularly useful to have on hand

during study of Water Transmission and Distribution include:

• Water Quality and Treatment. 6th ed. 2010. New York: McGraw-Hill and American Water WorksAssociation (available from AWWA).

• Manual of Water Utility Operations. 8th ed. 1988. Austin, Texas: Texas Water Utilities.

• Manual of Instruction for Water Treatment Plant Operators.1975. Albany, N.Y.: New York State

Department of Health.

• Back copies of the Journal AWWA and Opflow.

USE OF THE WORKBOOK

If you are using this workbook in conjunction with class instruction, you are urged to keep a loose-leaf note-

book for supplementary sheets distributed by the instructor, filed in the order in which the subjects are stud-ied. When your notes are carefully kept in order, they provide an excellent personal information source for

later review and reference.

The review questions are designed to highlight some of the major points of each chapter. You should

reread sections covered by the review questions until you can completely answer the questions. The instruc-

tor will then review the answers during a class period to make sure everyone understands the subject and has

provided the correct answers.

Your instructor usually will also provide supplemental assignments and furnish handout material for

each chapter. When the length of class meetings is limited, some chapters will be broken into segments and

covered during two or more meetings.

The workbook can also be used for individual study. Notes should be made of important points as the

text and references are read, and the review questions should be answered completely to ensure that the full

significance of important points is understood.

STATE AND FEDERAL REGULATIONS

Many aspects of water treatment and distribution system operation are now directed and regulated by federal

regulations. A review of federal regulations in effect at the time the second edition of this volume was pub-

lished is provided in Water Quality (another volume in this series). But many changes are expected within

coming years.


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Introduction: Using Your Student Workbook xiii

Although the states are generally required to enact regulations that are as stringent as the federal

requirements, they may, at times, vary, be more stringent, or include additional requirements. It is therefore

important that you obtain a reference copy of the latest state drinking water regulations for the state in which

you are working. Applicable sections of the regulations should then be reviewed in conjunction with your

study of each chapter.

QUIZZES AND EXAMINATIONS

If you are attending training classes, the instructor will probably give you a few quizzes during the course.

These are important to you in indicating whether you are adequately learning the material being presented;

they are also important to the instructor to determine if the material is being properly presented.

If you are studying this subject in preparation for taking a state certification examination, it is particu-

larly important that you become comfortable in taking exams of the type used by the state. If you would like

more review and practice in answering questions of the type used on certification exams, it is suggested that

you obtain the AWWA publication Operator Certification Study Guide, 6th ed., Denver, Colo.: American

Water Works Association.

Good Luck in Your Water Utility Career!


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1

CHAPTER 1

Introduction to WaterDistribution Systems

OBJECTIVES

After completing study of this chapter, you should be able to understand:

• the purpose of drinking water distribution systems

• the types of public water systems, categorized by water source

• the components of distribution systems

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 1, Introduction to Water Dis-

tribution Systems.

2. State public water supply regulations: Read sections relating to required state

approval of plans and specifications for water distribution system construction.

OTHER ASSIGNMENTS


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2 WSO: Water Transmission and Distribution Student Workbook

CLASS NOTES

1. System purpose:

2. Types of systems:

3. System planning issues:

4. Supply and distribution system components:


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Chapter 1: Introduction to Water Distribution Systems 3

REVIEW QUESTIONS

1. What are two purposes of drinking water distribution systems?

2. What is a “well field” and why is it sometimes installed?

3. Why are increasing numbers of public water systems purchasing their water from another utility?

4. What special features are typically included in a purchased water source system?

5. What is a rural water system?


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6. How do local conditions affect the design of distribution systems? Name two of these local

considerations:

7. What kind of local policy decisions could affect new system development or expansion?

8. Name six functional components of a conventional water supply system :

•

•

•

•

•

•

9. Name three components of a distribution system:

•

•

•


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Chapter 1: Introduction to Water Distribution Systems 5

STUDY PROBLEMS

1. You work for a public water system that uses surface water as a source. A housing development

near your distribution system would like you to extend your distribution system to accommodate

the houses in the development. Currently, the houses use a communal well for their water supply.

The home owners have asked if their distribution system can be directly connected to your public

water system. For your manager, put together a list of issues that would need to be resolved beforethe decision could be made.


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ADDITIONAL NOTES


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7

CHAPTER 2

Pipe Systems and Piping

OBJECTIVES


• the common configurations used in distribution system design

• the principal considerations involved in sizing water mains

• considerations that must be made when piping materials are selected

• the purpose of AWWA and ANSI/NSF standards• the four general types of piping used in water systems

• general characteristics of commonly used pipe materials

• principal advantages and disadvantages of each type of pipe

• types of joints and fittings primarily used with each type of pipe

READING ASSIGNMENTS

1. Water Transmission and Distribution:

• Read chapter 2, Pipe Systems and Piping.

• Read appendix A, Specifications and Approval of Treatment Chemicals and

System Components.

2. State public water supply regulations: Read sections relating to required state

approval of plans and specifications for water distribution system construction.

OTHER ASSIGNMENTS


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CLASS NOTES

1. System planning:

2. System layout:

3. Sizing mains:

4. Fire flow requirements:

5. Material selection:

6. Pipe uses:


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Chapter 2: Pipe Systems and Piping 9

7. Gray cast-iron pipe:

8. Ductile-iron pipe:

9. Steel pipe:

10. Asbestos–cement pipe:

11. PVC and other plastic pipe:

12. Concrete pipe:


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REVIEW QUESTIONS

1. What type of distribution system configuration is not recommended? Why?

2. Explain what determines the selection of main sizes.

3. What is the minimum main size recommended by the fire insurance underwriters?

4. What is a network analysis?


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5. What do AWWA standards define? What materials are covered by ANSI/NSF 61?

6. Explain what is meant by the C value of a pipe.

7. List seven unusual pipe installation conditions that might have a bearing on the type of pipe used

for a particular installation.

•

•

•

•

•

•

•

8. What are transmission lines?


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9. Identify five types of piping material commonly installed today in water distribution systems.

•

•

•

•

•

10. List some advantages and disadvantages of ductile-iron pipe.

11. List six common types of joints used with ductile-iron pipe, and describe the conditions under

which each may be used.

•

•

•

•

•

•

12. List some advantages and disadvantages of PVC pipe.


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STUDY PROBLEMS

1. Suppose your utility serves a population of 10,000 people. To meet increased demand in a new ser-

vice area, a main extension program is being considered. The soil in the area ranges from hardpan

to cobbles. Prepare statements supporting your recommendations for

• the selection of the best type of pipe to use

• the minimum size of main that should be installed

2. The present water source for your community (population 50,000) is no longer adequate. You are

considering running a main to a point 5 mi (8 km) away where a new well field can be established.

Assume this main would not have to go through any other communities. Contact contractors in

your area for the approximate cost per foot of installing a main for various types of pipe, assuming

soil and terrain conditions for your part of the country. Prepare a brief report of the considerations

that must be made and your recommendations for the pipeline.

3. Contact distribution system operators at several public water systems in the area and determine the

following information:

• If there are old water mains in the system:

—How old are the oldest mains?

—What type of pipe is it?

—What problems have there been with the pipes?

• For mains installed in recent years:

—What type of pipe is presently being installed?

—If the type is different than the old pipe, why was a change made?

—If a different type of pipe is now being used, what have the advantages and disadvantages

been?

From this information, compile some conclusions for your area on the following:

• the effect of local water quality and weather conditions on the selection of pipe materials

• the changes being made by water systems in the type of pipe that is being used

• reasons the water systems are changing or not changing the type of pipe being used


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ADDITIONAL NOTES


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15

CHAPTER 3

Water Storage

OBJECTIVES


• the principal reasons for storing water in the distribution system

• the difference between operating storage and emergency storage requirements

• common construction features and accessory devices for water storage tanks

• key factors that must be considered to select the proper size and location for awater reservoir

• important points in the operation and maintenance of water storage facilities

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 3, Water Storage.

2. State drinking water regulations: Read sections relating to requirements for the

type and amount of storage that must be provided.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Water storage requirements:

2. Types of treated-water storage facilities:

3. Locations of distribution storage systems:

4. Water storage facility equipment:

5. Operation and maintenance of water storage facilities:

6. Water storage facility safety:


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Chapter 3: Water Storage 17

REVIEW QUESTIONS

1. Identify nine reasons for providing water storage within a distribution system.

•

•

•

•

•

•

•

•

•

2. What is the difference between operating storage and emergency storage?

3. What are the advantages and disadvantages of elevated tanks, standpipes, and ground-level tanks?

4. Describe the operation and intended application of hydropneumatic storage.


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5. Materials of construction used for drinking water reservoirs must be in compliance with which

standards?

6. What is the benefit of having many smaller storage tanks in a distribution system instead of one

large tank?

7. List three types of piping found in every water tank.

•

•

•

8. After disinfection, what must be done before a water storage tank can be placed back in service?

9. List five safety precautions that must be observed during work inside storage tanks.

•

•

•

•

•


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Chapter 3: Water Storage 19

STUDY PROBLEMS

1. Obtain a map of a local community and locate all water storage facilities on it. Prepare a report dis-

cussing the advantages and disadvantages of each of the locations regarding elevation, position in

relation to population centers and sources of supply, hydraulics, and acceptability to the public.

2. Prepare a report discussing cold-weather problems that can be experienced with elevated storage

tanks, as well as what should be done to minimize the problems.


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ADDITIONAL NOTES


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21

CHAPTER 4

Pumping Stations and Pumps

OBJECTIVES


• the operating principles of common types of velocity and positive-displacement

pumps

• general operating procedure for centrifugal pumps and the reasons for these

procedures

• the regular preventive maintenance procedures required for centrifugal pumps

• the purpose and function of the principal parts of centrifugal pumps

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 4, Pumping Stations and

Pumps.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Types of pump stations:

2. Pump curves for pump stations:

3. Types of pumps:

4. Operation of centrifugal pumps:

5. Centrifugal pump maintenance:

6. Record keeping:

7. Pump safety:


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Chapter 4: Pumping Stations and Pumps 23

REVIEW QUESTIONS

1. What is the purpose of a booster pump station?

2. What two types of piping are found in a pump station?

3. What is the purpose of surge (pressure) relief valves in the discharge piping of a pump station?

4. What are the two basic categories of pumps used in water supply operations? What are the principal

water supply uses of each type?

•

•

5. What is the basic operating principle of a velocity pump?


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6. Identify one unique safety feature that velocity pumps have over positive-displacement pumps.

7. What is a multistage centrifugal pump? What effect does the design have on discharge pressure and

flow volume?

8. What are the two pump and motor arrangements commonly used for vertical turbine well pumps?

•

•

9. What type of vertical turbine pump is commonly used as an in-line booster pump?

10. Describe the two main parts of a jet pump.

•

•

11. What is the purpose of a foot valve installed on the suction pipe to a centrifugal pump?


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12. What is the function of the wear rings in the centrifugal pumps of the closed-impeller design? What

is the function of lantern rings?

13. Describe the two common types of seals used to control leakage between the pump shaft and the

casing.

•

•

14. What are the four steps that should be followed in greasing pump bearings?

•

•

•

•


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STUDY PROBLEMS

1. Outline the basic steps that should be considered during installation of a vertical turbine pump that

will pump from a wet well.

2. Visit the pump house at a local water system and record information on two or three different

makes or models of pumps that are in use. If possible, obtain a copy of the manufacturer’s pump

curve for each pump.

Obtain the following information for each unit:

• pump data: design type, name of manufacturer, model number, date of installation, types of

bearings, types of seals, and so on

• driving motor horsepower rating

• installation: inlet and outlet piping sizes, types of valves and valve operators, increases in pipe

sizes near the unit, and so on

• observations: suction and outlet pressures during operation, amount of water leaking from the

gland, pump noise, relative bearing temperature (i.e., hot or cool), noticeable vibration, and so on

From the collected data, prepare a brief report on each pump unit.

• Refer to the pump curve. At what theoretical efficiency is the pump operating?

• Does the pump appear to need repair or replacement?

• Does the water system maintain good records of its equipment and of the maintenance and

repair work performed?


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ADDITIONAL NOTES


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29

CHAPTER 5

Hydraulics of WaterDistribution Systems

OBJECTIVES


• how to calculate the flow of water in a pipe

• how the variables in the Hazen –Williams are determined

• the components and interactions of system hydraulics

• the capabilities and use of network analysis

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 5, Hydraulics of Water Dis-

tribution Systems.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Pipe flow calculations:

2. C -values:

3. Minor head loss:

4. Water demand:

5. Hydraulic dead end:

6. Water age:

7. Network analysis:

8. Water hammer:


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Chapter 5: Hydraulics of Water Distribution Systems 31

REVIEW QUESTIONS

1. What is a C -value? What is a typical C -value for a new unlined cast iron pipe?

2. What is the definition of friction slope (S f )?

3. What causes minor head loss in a water distribution network?

4. What is the minor loss coefficient associated with a 45° elbow?

5. What does a diurnal flow curve show?


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6. Why should dead ends be avoided in a water distribution system?

7. What factors can affect water age?

8. What impact does a pipe break have on the distribution system’s hydraulic performance?

9. What applications can EPANET be used for in distribution system analysis?

10. What causes water hammer in a water distribution system? What measures can be taken to avoid

water hammers in the distribution system?


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Chapter 5: Hydraulics of Water Distribution Systems 33

STUDY PROBLEM

1. You have been asked by your manager to investigate implementing a hydraulic model to describe

your utility’s distribution system. Research what software models are available in the public

domain for free (EPANET) or for purchase. Determine what data your utility will have to assemble

to put into one of these software models. Contact a nearby utility to find out if that utility uses a

hydraulic model and if so, what benefits they have found using the model.


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ADDITIONAL NOTES


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35

CHAPTER 6

Valves

OBJECTIVES


• the conditions under which different types of valves are installed in the distribution

system

• common types of valves and components

• the purpose of a valve exercise program and how one should be conducted

• recommended inspection checks and maintenance that should be performed on

valves

• the various types of valve operators used in water systems

• records that should be kept on distribution system valves

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 6, Valves.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Uses of water utility valves:

2. Types of water utility valves:

3. Valve operation:

4. Valve storage:

5. Valve joints:

6. Valve boxes and vaults:

7. Valve records:


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Chapter 6: Valves 37

REVIEW QUESTIONS

1. List nine uses for valves in a water distribution system.

•

•

•

•

•

•

•

•

•

2. Should gate valves be used for throttling flow? Why or why not?

3. Describe how an air-and-vacuum relief valve works.

4. What is the primary purpose of a bypass valve?


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5. When is an inserting valve installed in a water main?

6. What are the two principal uses of large check valves in a water system?

•

•

7. List three types of power operators for valves.

•

•

•

8. List the three most common types of joints used to install large water system valves.

•

•

•

9. What is the main purpose of valve boxes and vaults?

10. What factors must be kept in mind concerning drainage for valve vaults?


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Chapter 6: Valves 39

STUDY PROBLEMS

1. You are a distribution system operator and the director of public works has asked you to recom-

mend the types of valves to install on a new 14-in. (350-mm) transmission main. The required types

of valves will need to

• isolate the main from connecting mains

• throttle flow in the main

• prevent backflow into the main from a brewery

What are your recommendations and why?

2. You and a co-worker have been asked to shut off a valve in a vault. The worker enters the vault

without any safety equipment and collapses. What should you do? What should have been done to

ensure his or her safety?

3. Diagram or describe how you, by using landmarks, would pinpoint the location of a valve located

in a residential district.

4. You have just been employed as chief operator for a town serving 8,500 people. You soon discoverthere are no valve records. Describe how you would go about locating the valves in the distribution

system, and describe the types of records you would establish.


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ADDITIONAL NOTES


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41

CHAPTER 7

Fire Hydrants

OBJECTIVES


• the various uses of hydrants in a distribution system

• the difference between dry-barrel and wet-barrel hydrants

• principal components of dry-barrel and wet-barrel hydrants

• proper procedures for installing, operating, inspecting, and maintaining hydrants• the proper way to perform a hydrant flow test

• the information that should be recorded when fire hydrants are installed,

inspected, and repaired

• safety precautions that should be observed during fire hydrant flushing and testing

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 7, Fire Hydrants.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Fire hydrant uses:

2. Types of fire hydrants:

3. Hydrant parts:

4. Inspection and installation:

5. Operation and maintenance:

6. Hydrant records:

7. Hydrant safety:


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Chapter 7: Fire Hydrants 43

REVIEW QUESTIONS

1. List four of the common authorized uses for fire hydrants, other than for fire protection.

•

•

•

•

2. List four reasons why strict controls should be exercised over hydrant uses.

•

•

•

•

3. How can operation of a fire hydrant cause water quality problems?

4. Explain the principal difference between a dry-barrel and wet-barrel hydrant.

5. In relation to the street, what direction should the pumper nozzle be pointed?


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6. List two ways hydrants can be protected from damage by traffic.

•

•

7. List three important installation details that should be observed during the installation of dry-barrel

hydrants.

•

•

•

8. What is the purpose of a color-coding scheme for hydrant tops or caps?

9. Why is the speed at which hydrant valves are operated important?

10. Name three preventive measures that should be taken in cold-climate areas to ensure that hydrants

will remain operable during the winter.

•

•

•

11. List three items of information about the distribution system that can be obtained from hydrant flow

tests.

•

•

•


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12. Why is it important to record every hydrant inspection with an entry of the date and condition of the

hydrant?

13. List three items of information that should be included on a hydrant record form.

•

•

•

14. Name five safety precautions that should be taken during hydrant flushing and testing to prevent

injury to personnel and the public and to minimize damage to property.

•

•

•

•

•


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STUDY PROBLEMS

1. You have just taken over as operator of the distribution system for a community that presently has

no hydrant records. Obtain a copy of a blank hydrant record card from a neighboring water utility,

or make a copy of the example in the text. Using an existing hydrant in the area, complete the card

with information on the hydrant, a sketch, and location data.

Try to make the record as complete as possible. You may estimate the hydrant age based on the

hydrant model or by finding out when the main was installed. You may estimate the buried depth by

measuring the depth of the auxiliary valve.

2. Under the supervision of the instructor or an experienced operator, conduct a hydrant flow test and

determine the flow available from the test hydrant at 20 psi (140 kPa) residual pressure.

3. Under the supervision of the instructor or an experienced operator, provide a complete inspection of

an installed hydrant and mark the appropriate information on a record form.


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ADDITIONAL NOTES


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49

CHAPTER 8

Motors and Engines

OBJECTIVES


• the types of electric motors used to power water system equipment

• the principal types of motor control equipment used

• methods of improving the efficiency of electrically driven pumps

• the principal parts that must be periodically maintained or repaired in electricmotors and control equipment

• principal types of combustion engines used to power water system equipment

• important points in the operation and maintenance of engines

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 8, Motors and Engines.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Electricity terminology review:

2. Principles of electric motor operation:

3. Single-phase and three-phase motors:

4. Electric motor construction:

5. Motor control equipment:

6. Improving the efficiency of electrically driven pumps:


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Chapter 8: Motors and Engines 51

7. Maintenance of electric motors:

8. Types of combustion engines:

9. Operation and maintenance of internal-combustion engines:

10. Motor and engine records:

11. Motor and engine safety:


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REVIEW QUESTIONS

1. What is the relationship between volts, amps, and ohms that is expressed in Ohm’s law?

2. What is the maximum synchronous speed that a motor can operate at on 60-Hz power?

3. When do most electric motors draw the most current?

4. What can happen when a fuse blows on one leg of a three-phase circuit?

5. What are three major ways of reducing power costs where electrically driven pumps are used?

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6. What is the value of listening to a pump or motor and laying a hand on the unit as it operates?


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7. What effect could over lubrication of motor bearings have?

8. Why should emery cloth not be used around electrical equipment?

9. Name five common fuels for internal-combustion engines.

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10. List the type of information that should be recorded on a basic data card for pumping equipment.

11. What is the first rule of safety for repairing electrical devices?


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STUDY PROBLEMS

1. Outline a basic scheme for the periodic inspection and maintenance program of a pump house that

has four electric-motor-driven pumps and a diesel generator unit.

2. Review the stand-by power units installed at a local water system. Determine what the system’s

minimum, average, and maximum daily and hourly flow rates are, as well as the system’s history of

power outages.

Prepare a brief report describing how successful the system’s equipment is in meeting customer

water demands during power outages, and suggest what equipment could be changed or added if

the present equipment is not considered adequate.


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ADDITIONAL NOTES


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57

CHAPTER 9

Instrumentation and Control

OBJECTIVES


• the various types of primary and secondary instrumentation used in water system

operation

• the method of operation of common sensors

• how a basic telemetry system works

• ways in which manual, semiautomatic, and automatic control systems can be

arranged to operate

• how supervisory control and data acquisition (SCADA) systems can be used in

water system operation

• general requirements for maintenance of instruments and control equipment

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 9, Instrumentation and Control.

2. State drinking water regulations: Read sections pertaining to equipment automation.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Primary instrumentation:

2. Secondary instrumentation and telemetering:

3. Control systems:

4. Supervisory control and data acquisition:

5. Operation and maintenance:


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Chapter 9: Instrumentation and Control 59

REVIEW QUESTIONS

1. List six general types of primary instruments (sensors) commonly found in a water distribution

instrumentation system.

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2. Electrical measurements are commonly explained by comparison to similar variables used to

describe hydraulic conditions. Explain how voltage, current, and resistance are similar to conditions

measured in a water main.

3. What is the fourth commonly measured electrical variable not discussed in the previous question?

What units is it measured in? What does it indicate?

4. What is the purpose of secondary instruments?


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5. What is the difference between an analog and a digital indicator?

6. When is a telemetry system required?

7. Explain the four methods that can be used to obtain information or to control more than one system

over a single transmission channel.

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8. Distinguish among manual, automatic, and semiautomatic control systems.

9. What does SCADA stand for?


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Chapter 9: Instrumentation and Control 61

STUDY PROBLEMS

1. Select a single control station or pumping station on a local water system and trace the signal path

for a single simple instrument, such as a pressure or flow sensor. Identify each of the components of

the instruments and record the model name and manufacturer. Using the utility’s repair manuals or

manufacturer’s literature, investigate the internal construction of each component and identify the

function of each of the parts.

2. Determine what types of telemetry systems a local water utility uses, and for what functions.

• Are the equipment and the transmission channel owned or leased by the utility?

• Who is responsible for repairs?

• If a radio or microwave system is used, what repairs can be performed by a technician who does

not hold Federal Communications Commission (FCC) certification as a radio repair person?

• At the central control point for the distribution system, identify which systems are automatic,

manual, and semiautomatic.

• What alarms are installed in case of system failure?

• What backup systems are available if the central control station or telemetry lines fail?


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ADDITIONAL NOTES


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63

CHAPTER 10

Water Meters

OBJECTIVES


• the importance of metering water entering the distribution system as well as

water used by customers

• the basic operating principles of meters commonly used in water systems

• factors that influence the type and size of meter used for various purposes

• conditions that influence where meters are located

• records that should be maintained on meters

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 10, Water Meters.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Customer water meters:

2. Customer meter installation:

3. Meter reading:

4. Meter testing, maintenance, and repair:

5. Mainline metering:

6. Weirs:

7. Metering flumes:

8. Metering safety:


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Chapter 10: Water Meters 65

REVIEW QUESTIONS

1. What are two reasons for metering water customers?

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2. Name the two types of positive displacement meters commonly used on customer water services.

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3. Compound meters are generally used under what conditions?

4. List four factors that must be considered to select the correct size of meter.

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5. List 10 requirements for an acceptable meter installation.

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6. List four reasons a manifold (or battery) meter installation is used in place of a single large meter.

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7. What is a meter yoke? What are some of the advantages of using one?

8. List three basic elements in a meter test.

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9. What is the principle of operation of a venturi meter?

10. Explain the need for maintaining electrical continuity around the meter during removal.


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Chapter 10: Water Meters 67

STUDY PROBLEMS

1. Determine if your state has adopted requirements for the frequency of testing meters, and if so,

what those requirements are.

Check with managers of several local utilities and find out what their policy is for meter testing

and/or replacement. At the same time, determine the water source and treatment provided by each

system. Summarize the information, highlighting any apparent relationship between the frequency

of testing and other factors such as water quality, size of the system, and the cost of treated water

used by the system.

How do the state requirements for frequency of water meter testing compare with the frequency

suggested by the American Water Works Association (AWWA)?


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ADDITIONAL NOTES


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69

CHAPTER 11

Backflow Prevention andCross-Connection Control

OBJECTIVES


• public health hazards that are created by cross-connections

• factors that allow backflow and backsiphonage to occur

• types of installations or facilities that are likely to have cross-connections

• appropriate backflow-prevention devices that should be used based on the degree

of hazard involved

• steps required to establish and administer a cross-connection control program

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 11, Backflow Prevention and

Cross-Connection Control.

2. State drinking water regulations: Review requirements for public water systemsto have a cross-connection control program.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Cross-connection terminology:

2. Where cross-connections occur:

3. Types of cross-connections:

4. Public health significance of cross-connections:

5. Backflow control methods and devices:

6. Cross-connection control programs:

7. Records and reports:


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Chapter 11: Backflow Prevention and Cross-Connection Control 71

REVIEW QUESTIONS

1. Define a cross-connection.

2. Explain what is meant by backsiphonage and back pressure.

3. List four situations that can cause negative pressure in a potable water supply.

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4. List six waterborne diseases that are known to have occurred as a result of cross-connections.

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5. What is the most reliable backflow-prevention method?


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6. Is a single check valve positive protection against backflow? Why or why not?

7. How often should a reduced-pressure-zone backflow preventer be tested?

8. In what position should an atmospheric vacuum breaker be installed relative to a shutoff valve?

Why?

9. How does a vacuum breaker prevent backsiphonage?

10. List seven elements that are essential to implement and operate a cross-connection control program

successfully.

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Chapter 11: Backflow Prevention and Cross-Connection Control 73

STUDY PROBLEMS

1. Your city has just annexed a subdivision where homes will be provided water by your water utility,

but the homes originally had private wells and septic systems. After the hookups are completed, the

weather turns very dry and water demand increases. You notice that some water samples collected

near the new subdivision are showing high coliform counts.

The local health officer informs you that she is receiving numerous complaints of stomach disor-

ders and illness. Describe what you would do to investigate this situation, and include an explana-

tion as to the most likely cause of the problem and how it can be remedied.

2. A new hospital is being built in your city, and the director of public works has asked you to recom-

mend the cross-connection control devices for both the water connection to the hospital and at loca-

tions within the building. Prepare a report outlining your recommendations.

3. Describe the cross-connection control program in your community. If your community does not

have a program, describe features of a program you would propose.


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ADDITIONAL NOTES


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75

CHAPTER 12

Water Main Installation

OBJECTIVES


• how pipes and fittings should be handled and prepared for installation

• methods of excavation for water main installation

• safety precautions that should be observed during trenching and pipe installation,

and methods of preventing trench-wall failure

• procedures to be followed in laying pipe

• methods of making connections to existing mains

• the importance of blocking and anchoring mains against movement and the com-

mon restraint methods that are used

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter12, Water Main Installation.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Pipe shipment:

2. Pipe handling:

3. Excavation:

4. Laying pipe:


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Chapter 12: Water Main Installation 77

REVIEW QUESTIONS

1. Why should pipe be inspected before and during unloading?

2. How should pipe be unloaded?

3. List nine important points to be considered when pipe is to be strung at a jobsite.

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4. What eight factors usually determine the depth and width of a trench?

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5. Why should wide trenches be avoided?

6. Name four danger signs that indicate potential trench failure.

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7. What is the angle of repose of soil and why is it important?

8. List five typical causes of trench cave-ins.

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9. Why is the proper placement of bedding material important?

10. Why must joint materials and pipe ends be kept clean?

11. Explain why thrust blocks and anchors are important. Where should they be used?


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Chapter 12: Water Main Installation 79

STUDY PROBLEM

1. You have just been employed to supervise the installation of a mile of new 8-in. (200-mm)

polyvinyl chloride (PVC) water main that will service a newly annexed subdivision. Outline the

steps you would take from delivery of the pipe up to the time the trench is ready for backfilling to

ensure proper and safe installation of the pipe.


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ADDITIONAL NOTES


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81

CHAPTER 13

Backfilling, Main Testing, andInstallation Safety

OBJECTIVES


• proper methods of backfilling and compacting the backfill in an excavation

• procedures in pressure and leak testing of new water mains

• methods of flushing and disinfecting newly constructed or repaired water mains

• restoration of structures and vegetation following construction

• safety precautions that must be followed on a construction site to protect workers

and the public

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 13, Backfilling, Main Test-

ing, and Installation Safety.

2. State public water supply regulations:

• Read sections applying to required leakage and bacteriological testing of

water mains.

• Read sections applying to water utility safety.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Backfilling:

2. Pressure and leak testing:

3. Flushing and disinfection:

4. Final inspection:

5. Site restoration:

6. Water main installation safety:


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Chapter 13: B ackfilling, Main Testing, and Installation Safety 83

REVIEW QUESTIONS

1. List three methods that can be used to compact backfill material.

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2. Explain what steps should be followed after pipe is installed but before a new pipeline is placed in

service.

3. List three methods of disinfecting water mains and briefly explain how each method works.

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4. What is the usual procedure followed if a laboratory reports the results of the bacteriological test of

a new main as “positive”?

5. Why is it useful to take photographs or videotapes of a jobsite before construction?


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6. What are the four basic rules for lifting heavy objects by hand?

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7. What are two basic rules for working with a crane?

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8. List four items of commonly used personal protective gear that should be worn during construction.

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9. When should metal hard hats not be worn?

10. Name three safety precautions that should be taken when mains in traffic areas are being repaired.

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11. Why is it unwise to hurry unduly under emergency conditions?


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Chapter 13: B ackfilling, Main Testing, and Installation Safety 85

STUDY PROBLEMS

1. You are the supervisor of a crew of eight workers who are about to start a small construction project

that will consist of installing one block of 6-in. (150-mm) water main in a residential area. You have

a small backhoe, an end loader, a portable air compressor, and a dump truck available to do the

work. The soil in the area is only nominally stable.

A few days before the job is to begin, you must list all of the safety procedures that must be consid-

ered both before and during the construction. Compile the list into the following categories:

• personal safety equipment that each person on the job should have

• other safety equipment that you must be sure is available on the construction site when the job

begins

• instructions on proper safety procedures that you want to emphasize in a meeting with employees

on the day the job is started


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ADDITIONAL NOTES


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87

CHAPTER 14

System Operations

OBJECTIVES


• the importance and techniques for maintaining distribution system water quality

• the practices and procedures to ensure system reliability resulting in acceptable

pressure at all times and providing adequate flow for all distribution system uses

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 14, System Operations.

2. State drinking water regulations:

• Read sections on requirements for collecting distribution system samples for

analysis.

• Read sections relating to maintaining a specified pressure in the distribution

system.

3. ANSI/AWWA G200, Standard for Distribution System Operation and Management,

AWWA.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Water quality monitoring—routine and nonroutine:

2. System design for water quality enhancement—pipe network and storage facilities:

3. Operations and maintenance practices to maintain water quality:

• Controlling water age

• Maintaining positive pressure

• Controlling direction and velocity of flow

4. Flushing and cleaning:


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Chapter 14: System Operations 89

5. Lining water mains:

6. Controlling internal corrosion:

7. Distribution system inspection:

8. Leak detection and water loss control:

9. External pipeline corrosion:


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REVIEW QUESTIONS

1. What are five general steps that lead to optimized water quality in the distribution system?

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2. What are three major components of a distribution system sampling plan?

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3. List some system design considerations for both pipelines and storage facilities that could affect

water quality.

4. What are three issues to consider when operating a distribution system to maintain water quality?

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5. How do you determine the flow required to perform water main flushing to remove sediment? List

three precautions to take before beginning a flushing procedure.


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6. List five methods that may be used under various circumstances for cleaning water mains.

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7. What are some of the consequences of corrosive water and list some ways to reduce internal pipe-

line corrosion.

8. List at least two ways of detecting leaks. What are five main tasks in a distribution system water

audit?

9. List at least five factors that affect external pipeline corrosion.

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STUDY PROBLEMS

1. Obtain a water plat (portion of a water system pipeline map) showing mains, valves, and hydrants

for a small water system in your area. Develop a plan to perform directional flushing to effectively

improve water quality in any areas of low water usage.

2. Using the same map, organize a plan to conduct a leak detection survey using electronic equipment.

3. Obtain a water plat that contains at least one water storage facility. Develop an operational strategy

to keep the water fresh within this facility.


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ADDITIONAL NOTES


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95

CHAPTER 15

Water Services

OBJECTIVES


• what is meant by a service connection

• the components that make up a typical residential connection

• the principal factors that govern the size of water service lines

• factors that should be evaluated in the selection of pipe material used for a serviceconnection

• the different types and sizes of connections (taps) used to connect service lines

• the use of corporation stops and the different types available

• the method of operating the equipment used in making service taps

• the need for keeping good records of water service installations

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 15, Water Services.2. State drinking water regulations: Read sections relating to the Lead and Copper

Rule requirements.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Meter locations:

2. Service line sizes, materials, and equipment:

3. Water service taps:

4. Leaks and breaks:

5. Thawing:

6. Service line responsibility:

7. Service line records:


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Chapter 15: Water Services 97

REVIEW QUESTIONS

1. What is the purpose of water service lines?

2. Why is it a good policy to eliminate lead water services from the system whenever possible?

3. What is a possible problem when an iron service pipe is connected to a brass curb stop?

4. What is the most common type of inlet thread on a corporation stop? What is the major advantage

of this type of thread?

5. What is the function of a curb stop?

6. What are two advantages of a wet tap?


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7. When should a service clamp be used?

8. Explain the difference between a wet and dry tap.

9. What two precautions are recommended before a utility undertakes the thawing of customer water

services?

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10. List eight points of information that should be recorded after a tap is made, but before the excava-

tion is backfilled.

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Chapter 15: Water Services 99

STUDY PROBLEMS

1. Part of your system has copper service lines attached to ductile-iron mains. The system has just

expanded into a new service area that has PVC mains and high-molecular-weight polyethylene ser-

vice lines. All mains are 6 in. (150 mm) in diameter. Discuss the type of corporation stop and tap-

ping procedures you would recommend for each situation.

2. Contact two or more water utilities in your area and determine what types of materials they are

presently using for water services, how deep they require the pipe to be laid, and other details. From

this information, draw a cross-sectional sketch of a typical service, showing details for each system.

Comment on the possible reasons for differences in the practices of different systems.


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ADDITIONAL NOTES


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101

CHAPTER 16

Information Management

OBJECTIVES


• typical uses of computers in water system information management

• the importance of maintaining system maps, drawings, and records

• examples of maps, drawings, and records commonly used in distribution system

operations, as well as their purposes

• records that should be maintained for water distribution system equipment

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 16, Information Management.

2. State drinking water regulations: Review sections relating to (1) reports that must

be submitted to the state on distribution system operations and (2) requirements

for records that water systems must maintain on their equipment and facilities.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Computers:

2. Maps and records:

3. Maintenance management:

4. Other major information systems:


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Chapter 16: Information Management 103

REVIEW QUESTIONS

1. List the four broad categories of water utility applications of computers.

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2. Identify the type of map that provides a clear picture of the entire distribution system.

3. What is the name of the mapped record that provides a detailed picture of a portion of the distribu-

tion system?

4. Identify two methods of showing the mapped locations of valves and hydrants.

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5. What are plan and profile drawings?

6. What mapped record is often made up in reduced-scale reproductions for ease of handling in the

field?


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7. Identify three types of distribution system card records that are typically maintained and the basic

information each contains.

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8. What is included in an automated mapping/facility management/geographic information system

(AM/FM/GIS)? What is the objective of an AM/FM/GIS system in a water utility?

9. Name five items that would typically be included in distribution system statistical records. Whatinformation would each report contain?

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10. Name five points of information typically included on a work order.

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11. Explain the need for maintaining a file on technical information.


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Chapter 16: Information Management 105

STUDY PROBLEMS

1. You have just been appointed chief operator for a water system with 4,000 service connections. You

learn that there are no maps or records of the system’s facilities.

Describe the types of maps and records you would initiate and how you would obtain the necessary

information on existing facilities to start compiling the maps and records.

2. Examine the comprehensive map for a local water system to determine the system’s largest and

smallest mains.

What purpose do the largest mains serve? Do the smallest mains adversely affect customer service

or fire protection to areas of the system? If so, what methods could be used to correct the situation?


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ADDITIONAL NOTES


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107

CHAPTER 17

System Security andEmergency Response

OBJECTIVES


• the types of emergencies that could affect water utilities

• the areas that could make a water utility vulnerable

• the importance of protecting computer systems at a water utility

• the components of a Vulnerability Assessment

READING ASSIGNMENTS

1. Water Transmission and Distribution: Read chapter 17, System Security and

Emergency Response.

OTHER ASSIGNMENTS


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CLASS NOTES

1. Water supply system threats:

2. Cyber threats:

3. Physical threats:

4. Biological threats:

5. Chemical threats:


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Chapter 17: System Security and Emergency Response 109

6. Vulnerability Assessment:

7. SCADA system security

8. Early warning system:

9. Emergency response plan:


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REVIEW QUEST

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