Water treatment handbook

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Water treatment handbook

  1. 1. Frank R. Spellman Handbook of Water and Wastewater Treatment Plant Operations LEWIS PUBLISHERS A CRC Press Company Boca Raton London New York Washington, D.C.© 2003 by CRC Press LLC
  2. 2. Library of Congress Cataloging-in-Publication Data Spellman, Frank R. Handbook of water & wastewater treatment plant operations / by Frank R. Spellman. p. cm. Includes bibliographical references and index. ISBN 1-56670-627-0 (alk. paper) 1. Water—treatment plants—Handbooks, manuals, etc. 2. Sewage disposal plants—Handbooks, manuals, etc. 3. Water—PuriÞcation—Handbooks, manuals, etc. 4. Sewage—PuriÞcation—Handbooks, manuals, etc. I. Title: Handbook of water and wastewater treatment plant operations. II. Title. TD434.S64 2003 628.1¢62—dc21 2003040119This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources areindicated. A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and information, but the author and thepublisher cannot assume responsibility for the validity of all materials or for the consequences of their use.Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying,microÞlming, and recording, or by any information storage or retrieval system, without prior permission in writing from the publisher.The consent of CRC Press LLC does not extend to copying for general distribution, for promotion, for creating new works, or for resale. SpeciÞcpermission must be obtained in writing from CRC Press LLC for such copying.Direct all inquiries to CRC Press LLC, 2000 N.W. Corporate Blvd., Boca Raton, Florida 33431.Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identiÞcation and explanation,without intent to infringe. Visit the CRC Press Web site at www.crcpress.com © 2003 by CRC Press LLC Lewis Publishers is an imprint of CRC Press LLC No claim to original U.S. Government works International Standard Book Number 1-56670-627-0 Library of Congress Card Number 2003040119 Printed in the United States of America 1 2 3 4 5 6 7 8 9 0 Printed on acid-free paper © 2003 by CRC Press LLC
  3. 3. Preface Water does not divide; it connects. With simplicity it links privatization and the benchmarking process in this text. all aspects of our existence. On the other hand, how many of us thought security was a big deal prior to September 11? Some of us did, while David Rothenberg and Marta Ulvaenus some of us did not give it any thought at all. Today, things are different; we must adjust or fall behind. In the presentIn Handbook of Water and Wastewater Treatment Plant climate, falling behind on the security of our potable waterOperations, the intent of the author is twofold. The Þrst supplies is not an option. We must aggressively protectintent is to consolidate the information and experience in our precious water sources and those ancillaries that arewaterworks and wastewater treatment plant operations critical to maintaining and protecting water quality. Wethat have evolved as a result of technological advances in cover plant security concerns in this text.the Þeld, and as a result of the concepts and policies There are other current issues. For example, arsenicpromulgated by the environmental laws and the subse- in drinking water received a lot of coverage in the pressquent guidelines. The second intent is to discuss step-by- recently. We all know that arsenic is a deadly poison,step procedures for the correct and efÞcient operation of depending on dose, of course. Headlines stating thatwater and wastewater treatment systems. Tertiary to this arsenic has been found in certain municipal drinking watertwofold intent is the proper preparation of operators to supplies are a red ßag issue to many people. But is it reallyqualify for state licensure and certiÞcation examinations. an issue? We cover arsenic in drinking water in this text. With the impetus given to water quality improvement Another red ßag issue that has received some pressthrough the Municipal Construction Grants Program, the and the attention of regulators is the presence of patho-United States has undertaken an unprecedented building genic protozoans, such as Giardia and Cryptosporidium,program for new and improved water and wastewater treat- in drinking water supplies. We cover both of these proto-ment systems. To date, much emphasis has been placed on zoans in this text.training engineers to plan, design, and construct treatmentfacilities. At present, many programs in various engineer- In wastewater treatment (as well as water treatment),ing disciplines at many universities offer courses in water a lot of attention has been focused on disinfection by-and wastewater treatment plant design and operation. products in water efßuents outfalled into receiving water This text is not about the planning, designing, or con- bodies. We cover disinfection by-products in this text.struction of water and wastewater treatment facilities. Water and wastewater treatment is about mitigatingWhile these tasks are paramount to conception and con- the problems mentioned above. However, treatment oper-struction of needed facilities and needed infrastructure, ations are about much more. To handle today’s problems,many excellent texts are available that cover these impor- water and wastewater treatment system operators must betant areas. This text is not about engineering at all. Instead, generalists. Herein lies the problem. Many of the textsit is about operations and is designed for the operator. We presently available for water and wastewater operator useoften forget the old axiom: someone must build it, but are limited in scope and narrowly focused in content. Mostonce built, someone must operate it. It is the operation of of these texts take a bare bones approach to presentation.“it” that concerns us here. That is, the basics of each unit process are usually ade- Several excellent texts have been written on water and quately covered, but this is the extent of the coverage.wastewater treatment plant operations. Thus, the logical At present, available texts either ignore, avoid, or payquestion is, why a new text covering a well-trodden road? cursory attention to such important areas as the multiple- The compound answer is a text that is comprehensive barrier concept, maintaining infrastructure, benchmarking,in scope, current, and deals with real world problems plant security, operator roles, water hydraulics, microbi-involved with plant operations is needed. The simple ology, water ecology, basic electrical principles, pumping,answer is that after September 11, things have changed. conveyance, ßow measurement, basic water chemistry, Many of these changes were apparent before Septem- water quality issues, biomonitoring, sampling and testing,ber 11; at the same time, many of our present needs were water sources, and watershed protection. All of thesenot so apparent. Consider, for example, the need for plants important topics are thoroughly discussed in Handbook ofto become more efÞcient in operation and more economical Water and Wastewater Treatment Plant Operations.in practice. This is not new, but it now takes on added Though directed at water and wastewater operators,importance because of the threat of privatization. We cover this book will serve the needs of students; teachers; con- © 2003 by CRC Press LLC
  4. 4. sulting engineers; and technical personnel in city, state, the pertinent information for any problems you missed. Ifand federal organizations who must review operations and you miss many items, review the whole chapter.operating procedures. In order to maximize the usefulness The indented notes displayed in various locationsof the material contained in the test, it has been presented throughout this text indicate or emphasize importantin plain English in a simpliÞed and concise format. Many points to study carefully.tables have been developed, using a variety of sources. This text is accessible to those who have no experience with water and wastewater operations. If you work To assure correlation to modern practice and design, through the text systematically, you can acquire an under-illustrative problems are presented in terms of commonly standing of and skill in water and wastewater operations.used operational parameters. This will add a critical component to your professional Each chapter ends with a chapter review test to help knowledge.evaluate mastery of the concepts presented. Before goingon to the next chapter, take the review test, compare your Frank R. Spellmananswers to the key provided in Appendix A, and review Norfolk, VA © 2003 by CRC Press LLC
  5. 5. ContentsPART I Water and Wastewater Operations: An OverviewChapter 1 Problems Facing Water and Wastewater Treatment Operations1.1 Introduction1.2 The Paradigm Shift 1.2.1 A Change in the Way Things are Understood and Done1.3 Multiple-Barrier Concept 1.3.1 Multiple-Barrier Approach: Wastewater Operations1.4 Management Problems Facing Water and Wastewater Operations 1.4.1 Compliance with New, Changing, and Existing Regulations 1.4.2 Maintaining Infrastructure 1.4.3 Privatizing and/or Reengineering 1.4.4 Benchmarking 1.4.4.1 Benchmarking: The Process 1.4.5 The Bottom Line on Privatization1.5 Upgrading Security 1.5.1 The Bottom Line on Security1.6 Technical Management vs. Professional Management1.7 Chapter Review Questions and ProblemsReferencesChapter 2 Water and Wastewater Operators and Their Roles2.1 Water and Wastewater Operators2.2 Setting the Record Straight 2.2.1 The Computer-Literate Jack 2.2.2 Plant Operators as Emergency Responders 2.2.3 Operator Duties, Numbers, and Working Conditions2.3 Operator CertiÞcation/Licensure2.4 Chapter Review Questions and ProblemsReferencesChapter 3 Water and Wastewater References, Models, and Terminology3.1 Setting the Stage3.2 Treatment Process Models3.3 Key Terms Used in Waterworks and Wastewater Operations 3.3.1 Terminology and DeÞnitions3.4 Chapter Review Question and ProblemsReferences © 2003 by CRC Press LLC
  6. 6. PART II Water/Wastewater Operations: Math and Technical AspectsChapter 4 Water and Wastewater Math Operations4.1 Introduction4.2 Calculation Steps4.3 Table of Equivalents, Formulae, and Symbols4.4 Typical Water and Wastewater Math Operations 4.4.1 Arithmetic Average (or Arithmetic Mean) and Median 4.4.2 Ratio 4.4.3 Percent 4.4.3.1 Practical Percentage Calculations 4.4.4 Units and Conversions 4.4.4.1 Temperature Conversions 4.4.4.2 Milligrams per Liter (Parts per Million)4.5 Measurements: Areas and Volumes 4.5.1 Area of a Rectangle 4.5.2 Area of a Circle 4.5.3 Area of a Circular or Cylindrical Tank 4.5.4 Volume Calculations 4.5.4.1 Volume of Rectangular Tank 4.5.4.2 Volume of a Circular or Cylindrical Tank 4.5.4.3 Example Volume Problems4.6 Force, Pressure, and Head4.7 Flow 4.7.1 Flow Calculations 4.7.1.1 Instantaneous Flow Rates 4.7.1.2 Flow through a Full Pipeline 4.7.2 Velocity Calculations 4.7.3 Average Flow Rate Calculations 4.7.4 Flow Conversion Calculations4.8 Detention Time 4.8.1 Hydraulic Detention Time 4.8.1.1 Detention Time in Days 4.8.1.2 Detention Time in Hours 4.8.1.3 Detention Time in Minutes4.9 Chemical Dosage Calculations 4.9.1 Chlorine Dosage 4.9.2 Hypochlorite Dosage4.10 Percent Removal4.11 Population Equivalent or Unit Loading Factor4.12 SpeciÞc Gravity4.13 Percent Volatile Matter Reduction in Sludge4.14 Horsepower 4.14.1 Water Horsepower 4.14.2 Brake Horsepower 4.14.3 Motor Horsepower4.15 Electrical Power4.16 Chemical Coagulation and Sedimentation 4.16.1 Calculating Feed Rate 4.16.2 Calculating Solution Strength4.17 Filtration 4.17.1 Calculating the Rate of Filtration 4.17.2 Filter Backwash © 2003 by CRC Press LLC
  7. 7. 4.18 Practical Water Distribution System Calculations 4.18.1 Water Flow Velocity 4.18.2 Storage Tank Calculations 4.18.3 Distribution System Disinfection Calculations4.19 Complex Conversions 4.19.1 Concentration to Quantity 4.19.1.1 Concentration (Milligrams per Liter) to Pounds 4.19.1.2 Concentration (Milligrams per Liter) to Pounds/Day 4.19.1.3 Concentration (Milligrams per Liter) to Kilograms per Day 4.19.1.4 Concentration (milligrams/kilogram) to pounds/ton 4.19.2 Quantity to Concentration 4.19.2.1 Pounds to Concentration (Milligrams per Liter) 4.19.2.2 Pounds per Day to Concentration (Milligrams per Liter) 4.19.2.3 Kilograms per Day to Concentration (Milligrams per Liter) 4.19.3 Quantity to Volume or Flow Rate 4.19.3.1 Pounds to Tank Volume (Million Gallons) 4.19.3.2 Pounds per Day to Flow (Million Gallons per Day) 4.19.3.3 Kilograms per Day to Flow (Million Gallons per Day)4.20 Chapter Review Questions and ProblemsReferenceChapter 5 Water Hydraulics5.1 What is Water Hydraulics?5.2 Basic Concepts 5.2.1 Stevin’s Law5.3 Properties of Water 5.3.1 Density and SpeciÞc Gravity5.4 Force and Pressure 5.4.1 Hydrostatic Pressure 5.4.2 Effects of Water under Pressure5.5 Head 5.5.1 Static Head 5.5.2 Friction Head 5.5.3 Velocity Head 5.5.4 Total Dynamic Head (Total System Head) 5.5.5 Pressure/Head 5.5.6 Head/Pressure5.6 Flow/Discharge Rate: Water in Motion 5.6.1 Area/Velocity 5.6.2 Pressure/Velocity5.7 Piezometric Surface and Bernoulli’s Theorem 5.7.1 Law of Conservation of Energy 5.7.2 Energy Head 5.7.3 Piezometric Surface 5.7.3.1 Head Loss 5.7.3.2 Hydraulic Grade Line 5.7.4 Bernoulli’s Theorem 5.7.4.1 Bernoulli’s Equation5.8 Hydraulic Machines (Pumps) 5.8.1 Pumping Hydraulics5.9 Well and Wet Well Hydraulics 5.9.1 Well Hydraulics 5.9.2 Wet Well Hydraulics © 2003 by CRC Press LLC
  8. 8. 5.10 Friction Head Loss 5.10.1 Flow in Pipelines 5.10.2 Pipe and Open Flow Basics 5.10.3 Major Head Loss 5.10.3.1 Components of Major Head Loss 5.10.3.2 Calculating Major Head Loss 5.10.4 Minor Head Loss5.11 Basic Piping Hydraulics 5.11.1 Piping Networks 5.11.1.1 Energy Losses in Pipe Networks 5.11.1.2 Pipes in Series 5.11.1.3 Pipes in Parallel5.12 Open-Channel Flow 5.12.1 Characteristics of Open-Channel Flow 5.12.1.1 Laminar and Turbulent Flow 5.12.1.2 Uniform and Varied Flow 5.12.1.3 Critical Flow 5.12.1.4 Parameters Used in Open-Channel Flow 5.12.2 Open-Channel Flow Calculations 5.12.3 Open-Channel Flow: The Bottom Line5.13 Flow Measurement 5.13.1 Flow Measurement: The Old-Fashioned Way 5.13.2 Basis of Traditional Flow Measurement 5.13.3 Flow Measuring Devices 5.13.3.1 Differential Pressure Flowmeters 5.13.3.2 Magnetic Flowmeters 5.13.3.3 Ultrasonic Flowmeters 5.13.3.4 Velocity Flowmeters 5.13.3.5 Positive-Displacement Flowmeters 5.13.4 Open-Channel Flow Measurement 5.13.4.1 Weirs 5.13.4.2 Flumes5.14 Chapter Review Questions and ProblemsReferencesChapter 6 Fundamentals of Electricity6.1 Electricity: What Is It?6.2 Nature of Electricity6.3 The Structure of Matter6.4 Conductors, Semiconductors, and Insulators6.5 Static Electricity 6.5.1 Charged Bodies 6.5.2 Coulomb’s Law 6.5.3 Electrostatic Fields6.6 Magnetism 6.6.1 Magnetic Materials 6.6.2 Magnetic Earth6.7 Difference in Potential 6.7.1 The Water Analogy 6.7.2 Principal Methods of Producing Voltage6.8 Current6.9 Resistance6.10 Battery-Supplied Electricity © 2003 by CRC Press LLC
  9. 9. 6.10.1 The Voltaic Cell 6.10.2 Primary and Secondary Cells 6.10.3 Battery 6.10.3.1 Battery Operation 6.10.3.2 Combining Cells 6.10.4 Types of Batteries 6.10.4.1 Dry Cell 6.10.4.2 Lead-Acid Battery 6.10.4.3 Alkaline Cell 6.10.4.4 Nickel-Cadmium Cell 6.10.4.5 Mercury Cell 6.10.4.6 Battery Characteristics6.11 The Simple Electrical Circuit 6.11.1 Schematic Representation6.12 Ohm’s law6.13 Electrical Power 6.13.1 Electrical Power Calculations6.14 Electrical Energy6.15 Series DC Circuit Characteristics 6.15.1 Series Circuit Resistance 6.15.2 Series Circuit Current 6.15.3 Series Circuit Voltage 6.15.4 Series Circuit Power 6.15.5 Summary of the Rules for Series DC Circuits 6.15.6 General Series Circuit Analysis 6.15.6.1 Kirchhoff’s Voltage Law6.16 Ground6.17 Open and Short Circuits6.18 Parallel DC Circuits 6.18.1 Parallel Circuit Characteristics 6.18.2 Voltage in Parallel Circuits 6.18.3 Current in Parallel Circuits 6.18.4 Parallel Circuits and Kirchhoff’s Current Law 6.18.5 Parallel Circuit Resistance 6.18.5.1 Reciprocal Method 6.18.5.2 Product over the Sum Method 6.18.5.3 Reduction to an Equivalent Circuit 6.18.6 Power in Parallel Circuits 6.18.7 Rules for Solving Parallel DC Circuits6.19 Series-Parallel Circuits 6.19.1 Solving a Series-Parallel Circuit6.20 Conductors 6.20.1 Unit Size of Conductors 6.20.1.1 Square Mil 6.20.1.2 Circular Mil 6.20.1.3 Circular-Mil-Foot 6.20.1.4 Resistivity 6.20.1.5 Wire Measurement 6.20.2 Factors Governing the Selection of Wire Size 6.20.2.1 Copper vs. Other Metal Conductors 6.20.2.2 Temperature CoefÞcient 6.20.3 Conductor Insulation 6.20.4 Conductor Splices and Terminal Connections 6.20.5 Soldering Operations © 2003 by CRC Press LLC
  10. 10. 6.20.6 Solderless Connections 6.20.7 Insulation Tape6.21 Electromagnetism 6.21.1 Magnetic Field around a Single Conductor 6.21.2 Polarity of a Single Conductor 6.21.3 Field around Two Parallel Conductors 6.21.4 Magnetic Field of a Coil 6.21.4.1 Polarity of an Electromagnetic Coil 6.21.4.2 Strength of an Electromagnetic Field 6.21.5 Magnetic Units 6.21.6 Properties of Magnetic Materials 6.21.6.1 Permeability 6.21.6.2 Hysteresis 6.21.7 Electromagnets6.22 AC Theory 6.22.1 Basic AC Generator 6.22.1.1 Cycle 6.22.1.2 Frequency, Period, and Wavelength 6.22.2 Characteristic Values of AC Voltage and Current 6.22.2.1 Peak Amplitude 6.22.2.2 Peak-to-Peak Amplitude 6.22.2.3 Instantaneous Amplitude 6.22.2.4 Effective or Root-Mean-Square Value 6.22.2.5 Average Value 6.22.3 Resistance in AC Circuits 6.22.4 Phase Relationships6.23 Inductance 6.23.1 Self-Inductance 6.23.2 Mutual Inductance 6.23.3 Calculation of Total Inductance6.24 Practical Electrical Applications 6.24.1 Electrical Power Generation 6.24.2 DC Generators 6.24.3 AC Generators 6.24.4 Motors 6.24.4.1 DC Motors 6.24.4.2 AC Motors 6.24.5 Transformers 6.24.6 Power Distribution System Protection 6.24.6.1 Fuses 6.24.6.2 Circuit Breakers 6.24.6.3 Control Devices6.25 Chapter Review Questions and ProblemsChapter 7 Hydraulic Machines: Pumps7.1 Introduction7.2 Archimedes’ Screw7.3 Pumping Hydraulics 7.3.1 DeÞnitions7.4 Basic Principles of Water Hydraulics 7.4.1 Weight of Air 7.4.2 Weight of Water 7.4.3 Weight of Water Related to the Weight of Air 7.4.4 Water at Rest © 2003 by CRC Press LLC
  11. 11. 7.4.5 Gauge Pressure 7.4.6 Water in Motion 7.4.6.1 Discharge 7.4.6.2 The Law of Continuity 7.4.7 Pipe Friction7.5 Basic Pumping Calculations 7.5.1 Pumping Rates 7.5.2 Calculating Head Loss 7.5.3 Calculating Head 7.5.4 Calculating Horsepower and EfÞciency 7.5.4.1 Hydraulic Horsepower 7.5.4.2 Pump EfÞciency and Brake Horsepower 7.5.5 SpeciÞc Speed7.6 Pump Characteristic Curves 7.6.1 Head-Capacity Curve 7.6.2 The Power-Capacity Curve 7.6.3 The EfÞciency-Capacity (E-Q) Curve7.7 Pumps in Series and Parallel7.8 Considerations for Pumping Wastewater7.9 Types of Pumps Used in Water and Wastewater Treatment7.10 Introduction to Centrifugal Pumps 7.10.1 Description 7.10.2 Theory 7.10.3 Types of Centrifugal Pumps 7.10.3.1 Radial Flow Impeller Pumps 7.10.3.2 Mixed Flow Impeller Pumps 7.10.3.3 Axial Flow Impeller Pumps (Propeller Pump) 7.10.4 Characteristics and Performance Curves 7.10.4.1 Head-Capacity Curve 7.10.4.2 EfÞciency Curve 7.10.4.3 Brake Horsepower Curves 7.10.5 Advantages and Disadvantages of a Centrifugal Pump 7.10.5.1 Advantages 7.10.5.2 Disadvantages 7.10.6 Water and Wastewater Applications7.11 Centrifugal Pump Components 7.11.1 Casing 7.11.1.1 Solid Casing 7.11.1.2 Split Casings 7.11.2 Impeller 7.11.2.1 Semiopen Impeller 7.11.2.2 Open Impeller 7.11.2.3 Closed Impeller 7.11.3 Wear Rings 7.11.4 Shafts, Sleeves, and Couplings 7.11.4.1 Shafting 7.11.4.2 Sleeves 7.11.4.3 Couplings 7.11.5 StufÞng Box and Seals 7.11.5.1 StufÞng Box or Packing Assembly 7.11.5.2 Mechanical Seals 7.11.6 Bearings 7.11.6.1 Self-Aligning Double-Row Ball Bearing 7.11.6.2 Single- or Double-Row Antifriction Ball Bearing 7.11.6.3 Angular Contact Bearings © 2003 by CRC Press LLC
  12. 12. 7.11.6.4 Self-Aligning Spherical Roller Bearings 7.11.6.5 Single-Row Tapered Roller Bearings 7.11.6.6 Bearing Installation, Maintenance and Lubrication7.12 Centrifugal Pump: Operational Procedures 7.12.1 Installation 7.12.2 Start-Up 7.12.2.1 Start-Up Procedure 7.12.3 Normal Operation 7.12.4 Shutdown 7.12.5 Priming 7.12.5.1 Priming Procedure 7.12.6 Backßushing 7.12.6.1 Backßush Procedure 7.12.7 Manual Removal Procedure7.13 Centrifugal Pump: Maintenance Procedures 7.13.1 Pump and Motor Lubrication 7.13.2 Packing and Seal Replacement 7.13.2.1 Packing Procedure 7.13.2.2 Mechanical Seal Installation Procedure 7.13.3 Pump and Motor Bearing Inspection 7.13.4 Shaft and Coupling Alignment 7.13.4.1 Alignment Procedure 7.13.4.2 Removal of Obstructions7.14 Centrifugal Pumps Preventive Maintenance 7.14.1 Daily Maintenance 7.14.2 Weekly Maintenance 7.14.3 Monthly Maintenance 7.14.4 Quarterly Maintenance 7.14.5 Semiannual Maintenance7.15 Centrifugal Pump Lubrication 7.15.1 Purpose of Lubrication 7.15.1.1 Separates Surfaces 7.15.1.2 Prevents Wear 7.15.1.3 Cushions Shock 7.15.1.4 Transfers Heat 7.15.1.5 Corrosion Protection 7.15.1.6 Protective Seal 7.15.2 Lubrication Requirements 7.15.3 Lubrication Procedures 7.15.3.1 Motor Bearing Lubrication 7.15.3.2 Pump Bearing Lubrication7.16 Centrifugal Pump: Troubleshooting 7.16.1 The Troubleshooter 7.16.2 Troubleshooting: What Is It? 7.16.3 Goals of Troubleshooting 7.16.4 The Troubleshooting Process 7.16.5 Troubleshooting the Centrifugal Pump 7.16.5.1 Pump Fails to Prime or Loses its Prime 7.16.5.2 Pump Does Not Discharge 7.16.5.3 Pump Does Not Deliver Rated Capacity 7.16.5.4 Pump Does Not Deliver SufÞcient Pressure 7.16.5.5 Pump Starts and Stops Pumping 7.16.5.6 Pump Overloads Driver or Consumes Excessive Power 7.16.5.7 Pump Is Noisy or Has Extensive Vibration 7.16.5.8 Packing Has a Short Life © 2003 by CRC Press LLC
  13. 13. 7.16.5.9 Mechanical Seal Has a Short Life 7.16.5.10 Mechanical Seal Leaks Excessively 7.16.5.11 Bearings Have a Short Life 7.16.5.12 Pump Overheats or Seizes7.17 Centrifugal Pump ModiÞcations 7.17.1 Submersible Pumps 7.17.1.1 Applications 7.17.1.2 Advantages 7.17.1.3 Disadvantages 7.17.2 Recessed Impeller or Vortex Pumps 7.17.2.1 Applications 7.17.2.2 Advantages 7.17.2.3 Disadvantages 7.17.3 Turbine Pumps 7.17.3.1 Application 7.17.3.2 Advantages 7.17.3.3 Disadvantages7.18 Positive-Displacement Pumps 7.18.1 Reciprocating Pumps 7.18.1.1 Diaphragm Pumps 7.18.1.2 Metering Pumps 7.18.1.3 Rotary Pumps 7.18.1.4 Progressive-Cavity Pump 7.18.1.5 Special Purpose Pumps7.19 Chapter Review Questions and ProblemsReferencesChapter 8 Water and Wastewater Conveyance8.1 Delivering the Lifeblood of Civilization8.2 Conveyance Systems 8.2.1 DeÞnitions 8.2.2 Fluids vs. Liquids 8.2.3 Maintaining Fluid Flow in Piping Systems 8.2.3.1 Scaling 8.2.4 Piping System Maintenance 8.2.5 Valves 8.2.6 Piping System Accessories 8.2.7 Piping Systems: Temperature Effects 8.2.8 Piping Systems: Insulation8.3 Metallic Piping 8.3.1 Piping Materials 8.3.2 Piping: The Basics 8.3.2.1 Pipe Sizes 8.3.2.2 Pipe Wall Thickness 8.3.2.3 Piping ClassiÞcation 8.3.3 Types of Piping Systems 8.3.3.1 Code for IdentiÞcation of Pipelines 8.3.4 Metallic Piping Materials 8.3.4.1 Characteristics of Metallic Materials 8.3.5 Maintenance Characteristics of Metallic Piping 8.3.5.1 Expansion and Flexibility 8.3.5.2 Pipe Support Systems 8.3.5.3 Valve Selection 8.3.5.4 Isolation © 2003 by CRC Press LLC
  14. 14. 8.3.5.5 Preventing Backßow 8.3.5.6 Water Hammer 8.3.5.7 Air Binding 8.3.5.8 Corrosion Effects 8.3.6 Joining Metallic Pipe 8.3.6.1 Bell-and-Spigot Joints 8.3.6.2 Screwed or Threaded Joints 8.3.6.3 Flanged Joints 8.3.6.4 Welded Joints 8.3.6.5 Soldered and Brazed Joints8.4 Nonmetallic Piping 8.4.1 Nonmetallic Piping Materials 8.4.1.1 Clay Pipe 8.4.1.2 Concrete Pipe 8.4.1.3 Plastic Pipe8.5 Tubing 8.5.1 Tubing vs. Piping: The Difference 8.5.1.1 Tubing 8.5.2 Advantages of Tubing 8.5.2.1 Tubing: Mechanical Advantages 8.5.2.2 Chemical Advantages 8.5.3 Connecting Tubing 8.5.3.1 Cutting Tubing 8.5.3.2 Soldering Tubing 8.5.3.3 Connecting Flared/Nonßared Joints 8.5.4 Bending Tubing 8.5.5 Types of Tubing 8.5.5.1 Typical Tubing Applications8.6 Industrial Hoses 8.6.1 Hose Nomenclature 8.6.2 Factors Governing Hose Selection 8.6.3 Standards, Codes, and Sizes 8.6.3.1 Hose Size 8.6.4 Hose ClassiÞcations 8.6.4.1 Nonmetallic Hoses 8.6.4.2 Metallic Hoses 8.6.5 Hose Couplings 8.6.6 Hose Maintenance8.7 Pipe and Tube Fittings 8.7.1 Fittings 8.7.2 Functions of Fittings 8.7.2.1 Changing the Direction of Flow 8.7.2.2 Providing Branch Connections 8.7.2.3 Changing the Sizes of Lines 8.7.2.4 Sealing Lines 8.7.2.5 Connecting Lines 8.7.3 Types of Connections 8.7.3.1 Screwed Fittings 8.7.3.2 Flanged Connections 8.7.3.3 Connections 8.7.4 Tubing Fittings and Connections8.8 Valves 8.8.1 Valve Construction 8.8.2 Types of Valves © 2003 by CRC Press LLC
  15. 15. 8.8.2.1 Ball Valves 8.8.2.2 Gate Valves 8.8.2.3 Globe Valves 8.8.2.4 Needle Valves 8.8.2.5 Butterßy Valves 8.8.2.6 Plug Valves 8.8.2.7 Check Valves 8.8.2.8 Quick-Opening Valves 8.8.2.9 Diaphragm Valves 8.8.2.10 Regulating Valves 8.8.2.11 Relief Valves 8.8.2.12 Reducing Valves 8.8.3 Valve Operators 8.8.3.1 Pneumatic and Hydraulic Valve Operators 8.8.3.2 Magnetic Valve Operators 8.8.4 Valve Maintenance8.9 Piping System: Protective Devices 8.9.1 Applications 8.9.2 Strainers 8.9.3 Filters 8.9.4 Traps 8.9.4.1 Trap Maintenance and Testing8.10 Piping Ancillaries 8.10.1 Gauges 8.10.1.1 Pressure Gauges 8.10.2 Vacuum Breakers 8.10.3 Accumulators 8.10.4 Air Receivers 8.10.5 Heat Exchangers8.11 Chapter Review Questions and ProblemsReferencesChapter 9 Flow Measurement9.1 Introduction9.2 Methods of Measuring Flow 9.2.1 Weirs 9.2.2 The Oscillating Disk Water Meter 9.2.3 Flumes 9.2.4 Venturi Meter 9.2.5 Magnetic Flowmeter9.3 Flow Measurement Calculations 9.3.1 Calculation Method Used for Fill and Draw Technique 9.3.2 Calculation Method Used for Velocity/Area Technique 9.3.3 Calculation Method Used for V-Notch Weirs 9.3.4 Weir Overßow (Weir Loading Rate) 9.3.5 Calculation Method for Parshall Flume 9.3.6 Typical Flow Measurement Practice Calculations9.4 Flow Measurement Operational Problems9.5 Chapter Review Questions and ProblemsReferences © 2003 by CRC Press LLC
  16. 16. Part III Characteristics of WaterChapter 10 Basic Water Chemistry10.1 Introduction10.2 Chemistry Concepts and DeÞnitions 10.2.1 Concepts 10.2.2 DeÞnitions10.3 Water Chemistry Fundamentals 10.3.1 Matter 10.3.1.1 The Content of Matter: The Elements 10.3.2 Compound Substances10.4 The Water Molecule10.5 Water Solutions10.6 Water Constituents 10.6.1 Solids 10.6.2 Turbidity 10.6.3 Color 10.6.4 Dissolved Oxygen 10.6.5 Metals 10.6.6 Organic Matter 10.6.7 Inorganic Matter 10.6.7.1 Acids 10.6.7.2 Bases 10.6.7.3 Salts10.7 pH10.8 Alkalinity10.9 Hardness10.10 Water and Wastewater Chemicals and Chemical Processes 10.10.1 Odor Control (Wastewater Treatment) 10.10.2 Disinfection 10.10.3 Chemical Precipitation 10.10.4 Adsorption 10.10.5 Coagulation 10.10.6 Taste and Odor Removal 10.10.7 Water Softening 10.10.8 Recarbonation 10.10.9 Ion Exchange Softening 10.10.10 Scaling and Corrosion Control10.11 Chapter Review Questions and ProblemsReferencesChapter 11 Water Microbiology11.1 Introduction11.2 Microbiology: What Is It?11.3 Water and Wastewater Microorganisms 11.3.1 Key Terms 11.3.2 Microorganisms (in General) 11.3.3 ClassiÞcation 11.3.4 Differentiation 11.3.5 The Cell 11.3.5.1 Structure of the Bacterial Cell © 2003 by CRC Press LLC
  17. 17. 11.4 Bacteria 11.4.1 Bacterial Growth Factors 11.4.2 Destruction of Bacteria 11.4.3 Waterborne Bacteria11.5 Protozoa11.6 Microscopic Crustaceans11.7 Viruses11.8 Algae11.9 Fungi11.10 Nematodes and Flatworms (Worms)11.11 Pathogenic Protozoa and Helminths (Water) 11.11.1 Pathogenic Protozoa 11.11.1.1 Giardia 11.11.1.2 Cryptosporidium 11.11.1.3 Cyclospora 11.11.2 Helminths11.12 Biological Aspects and Processes (Wastewater) 11.12.1 Aerobic Process 11.12.2 Anaerobic Process 11.12.3 Anoxic Process 11.12.4 Photosynthesis 11.12.5 Growth Cycles 11.12.6 Biogeochemical Cycles 11.12.6.1 Carbon Cycle 11.12.6.2 Nitrogen Cycle 11.12.6.3 Sulfur Cycle 11.12.6.4 Phosphorus Cycle11.13 Chapter Review Questions and ProblemsReferencesChapter 12 Water Ecology12.1 Introduction12.2 Setting the Stage12.3 Ecology Terms 12.3.1 DeÞnition of Terms12.4 Levels of Organization12.5 Ecosystem12.6 Energy Flow in the Ecosystem12.7 Food Chain EfÞciency12.8 Ecological Pyramids12.9 Productivity12.10 Population Ecology12.11 Stream Genesis and Structure 12.11.1 Water Flow in a Stream 12.11.2 Stream Water Discharge 12.11.3 Transport of Material 12.11.4 Characteristics of Stream Channels 12.11.5 Stream ProÞles 12.11.6 Sinuosity 12.11.7 Bars, Rifßes, and Pools 12.11.8 The Floodplain 12.11.9 Adaptations to Stream Current © 2003 by CRC Press LLC
  18. 18. 12.11.10 Types of Adaptive Changes 12.11.11 SpeciÞc Adaptations12.12 Benthic Life: An Overview 12.12.1 Benthic Plants and Animals12.13 Benthic Macroinvertebrates 12.13.1 IdentiÞcation of Benthic Macroinvertebrates 12.13.2 Macroinvertebrates and the Food Web 12.13.3 Units of Organization 12.13.4 Typical Running Water Benthic Macroinvertebrates12.14 Insect Macroinvertebrates 12.14.1 Mayßies (Order: Ephemeroptera) 12.14.2 Stoneßies (Order: Plecoptera) 12.14.3 Caddisßies (Order: Trichoptera) 12.14.4 True Flies (Order: Diptera) 12.14.5 Beetles (Order: Coleoptera) 12.14.6 Water Strider (Jesus bugs; Order: Hemiptera) 12.14.7 Alderßies and Dobsonßies (Order: Megaloptera) 12.14.8 Dragonßies and Damselßies (Order: Odonata)12.15 Noninsect Macroinvertebrates 12.15.1 Oligochaeta (Family: TuiÞcidae; Genus: Tubifex) 12.15.2 Hirudinea (Leeches) 12.14.3 Gastropoda (Lung-Breathing Snail)12.16 Chapter Review Questions and ProblemsReferencesChapter 13 Water Quality13.1 Introduction13.2 The Water Cycle13.3 Water Quality Standards 13.3.1 Clean Water Act (1972) 13.3.2 Safe Drinking Water Act (1974)13.4 Water Quality Characteristics of Water and Wastewater 13.4.1 Physical Characteristics of Water and Wastewater 13.4.1.1 Solids 13.4.1.2 Turbidity 13.4.1.3 Color 13.4.1.4 Taste and Odor 13.4.1.5 Temperature 13.4.2 Chemical Characteristics of Water 13.4.2.1 Total Dissolved Solids (TDS) 13.4.2.2 Alkalinity 13.4.2.3 Hardness 13.4.2.4 Fluoride 13.4.2.5 Metals 13.4.2.6 Organics 13.4.2.7 Nutrients 13.4.3 Chemical Characteristics of Wastewater 13.4.3.1 Organic Substances 13.4.3.2 Inorganic Substances 13.4.4 Biological Characteristics of Water and Wastewater 13.4.4.1 Bacteria 13.4.4.2 Viruses 13.4.4.3 Protozoa 13.4.4.4 Worms (Helminths) © 2003 by CRC Press LLC
  19. 19. 13.5 Chapter Review Questions and ProblemsReferencesChapter 14 Biomonitoring, Monitoring, Sampling, and Testing14.1 What Is Biomonitoring? 14.1.1 Biotic Indices (Streams) 14.1.1.1 Benthic Macroinvertebrate Biotic Index14.2 Biological Sampling (Streams) 14.2.1 Biological Sampling: Planning 14.2.2 Sampling Stations 14.2.3 Sample Collection 14.2.3.1 Macroinvertebrate Sampling Equipment 14.2.3.2 Macroinvertebrate Sampling: Rocky-Bottom Streams 14.2.3.3 Macroinvertebrate Sampling: Muddy-Bottom Streams 14.2.4 Postsampling Routine 14.2.4.1 Sampling Devices 14.2.5 The Bottom Line on Biological Sampling14.3 Water Quality Monitoring (Drinking Water) 14.3.1 Is the Water Good or Bad? 14.3.2 State Water Quality Standards Programs 14.3.3 Designing a Water Quality Monitoring Program 14.3.4 General Preparation and Sampling Considerations 14.3.4.1 Method A: General Preparation of Sampling Containers 14.3.4.2 Method B: Acid Wash Procedures 14.3.5 Sample Types 14.3.6 Collecting Samples from a Stream 14.3.6.1 Whirl-pak® Bags 14.3.6.2 Screw-Cap Bottles 14.3.7 Sample Preservation and Storage 14.3.8 Standardization of Methods14.4 Test Methods (Drinking Water and Wastewater) 14.4.1 Titrimetric Methods 14.4.2 Colorimetric Methods 14.4.3 Visual Methods 14.4.4 Electronic Methods 14.4.5 Dissolved Oxygen Testing 14.4.5.1 Sampling and Equipment Considerations 14.4.5.2 Dissolved Oxygen Test Methods 14.4.6 Biochemical Oxygen Demand Testing 14.4.6.1 Sampling Considerations 14.4.6.2 BOD Sampling, Analysis, and Testing 14.4.7 Temperature Measurement 14.4.7.1 Sampling and Equipment Considerations 14.4.8 Hardness Measurement 14.4.8.1 Measuring Hardness 14.4.9 pH Measurement 14.4.9.1 Analytical and Equipment Considerations 14.4.9.2 pH Meters 14.4.9.3 pH Pocket Pals and Color Comparators © 2003 by CRC Press LLC
  20. 20. 14.4.10 Turbidity Measurement 14.4.10.1 Sampling and Equipment Considerations 14.4.10.2 Using a Secchi Disk 14.4.10.3 Transparency Tube 14.4.11 Orthophosphate Measurement 14.4.11.1 Forms of Phosphorus 14.4.11.2 The Phosphorus Cycle 14.4.11.3 Testing Phosphorus 14.4.11.4 Sampling and Equipment Considerations 14.4.11.5 Ascorbic Acid Method for Determining Orthophosphate 14.4.12 Nitrates Measurement 14.4.12.1 Sampling and Equipment Considerations 14.4.12.2 Cadmium Reduction Method 14.4.12.3 Nitrate Electrode Method 14.4.13 Solids Measurement 14.4.13.1 Solids Sampling and Equipment Considerations 14.4.13.2 Total Suspended Solids 14.4.13.3 Volatile Suspended Solids Testing 14.4.14 Conductivity Testing 14.4.14.1 Sampling, Testing, and Equipment Considerations 14.4.15 Total Alkalinity 14.4.15.1 Analytical and Equipment Considerations 14.4.15.2 Burets, Titrators, and Digital Titrators for Measuring Alkalinity 14.4.16 Fecal Coliform Bacteria Testing 14.4.16.1 Fecal Coliforms: General Information 14.4.16.2 Fecal Coliforms 14.4.16.3 Sampling Requirements 14.4.16.4 Sampling and Equipment Considerations 14.4.16.5 Fecal Coliform Testing 14.4.17 Apparent Color Testing/Analysis 14.4.18 Odor Analysis of Water 14.4.19 Chlorine Residual Testing/Analysis 14.4.19.1 DPD-Spectrophotometric 14.4.19.2 DPD-FAS Titration 14.4.19.3 Titrimetric–Amperometric Direct Titration 14.4.20 Fluorides14.5 Chapter Review Questions and ProblemsReferencesPart IV Water and Water TreatmentChapter 15 Potable Water Sources15.1 Introduction 15.1.1 Key Terms and DeÞnitions 15.1.2 Hydrologic Cycle15.2 Sources of Water15.3 Surface Water 15.3.1 Advantages and Disadvantages of Surface Water 15.3.2 Surface Water Hydrology 15.3.3 Raw Water Storage 15.3.4 Surface Water Intakes 15.3.5 Surface Water Screens 15.3.6 Surface Water Quality © 2003 by CRC Press LLC
  21. 21. 15.4 Groundwater 15.4.1 Groundwater Quality15.5 GUDISW15.6 Surface Water Quality and Treatment Requirements15.7 Public Water System Use Requirements15.8 Well Systems 15.8.1 Well Site Requirements 15.8.2 Types of Wells 15.8.2.1 Shallow Wells 15.8.2.2 Deep Wells 15.8.3 Components of a Well 15.8.3.1 Well Casing 15.8.3.2 Grout 15.8.3.3 Well Pad 15.8.3.4 Sanitary Seal 15.8.3.5 Well Screen 15.8.3.6 Casing Vent 15.8.3.7 Drop Pipe 15.8.3.8 Miscellaneous Well Components 15.8.4 Well Evaluation 15.8.5 Well Pumps 15.8.6 Routine Operation and Record Keeping Requirements 15.8.6.1 Well Log 15.8.7 Well Maintenance 15.8.7.1 Troubleshooting Well Problems 15.8.8 Well Abandonment15.9 Chapter Review Questions and ProblemsReferenceChapter 16 Watershed Protection16.1 Introduction16.2 Current Issues in Water Management16.3 What is a Watershed?16.4 Water Quality Impact16.5 Watershed Protection and Regulations16.6 A Watershed Protection Plan16.7 Reservoir Management Practices16.8 Watershed Management Practices16.9 Chapter Review Questions and ProblemsReferenceChapter 17 Water Treatment Operations and Unit Processes17.1 Introduction17.2 Waterworks Operators17.3 Purpose of Water Treatment17.4 Stages of Water Treatment17.5 Pretreatment 17.5.1 Aeration 17.5.2 Screening 17.5.3 Chemical Addition 17.5.3.1 Chemical Solutions 17.5.3.2 Chemical Feeders 17.5.3.3 Chemical Feeder Calibration © 2003 by CRC Press LLC
  22. 22. 17.5.3.4 Iron and Manganese Removal 17.5.3.5 Hardness Treatment 17.5.3.6 Corrosion Control17.6 Coagulation 17.6.1 Jar Testing Procedure17.7 Flocculation17.8 Sedimentation17.9 Filtration 17.9.1 Types of Filter Technologies 17.9.1.1 Slow Sand Filters 17.9.1.2 Rapid Sand Filters 17.9.1.3 Pressure Filter Systems 17.9.1.4 Diatomaceous Earth Filters 17.9.1.5 Direct Filtration 17.9.1.6 Alternate Filters 17.9.2 Common Filter Problems 17.9.3 Filtration and Compliance with Turbidity Requirements (IESWTR) 17.9.3.1 Regulatory Requirements 17.9.3.2 Individual Filter Monitoring 17.9.3.3 Reporting and Record Keeping 17.9.3.4 Additional Compliance Issues17.10 Disinfection 17.10.1 Need for Disinfection in Water Treatment. 17.10.2 Pathogens of Primary Concern 17.10.2.1 Bacteria 17.10.2.2 Viruses 17.10.2.3 Protozoa 17.10.3 Recent Waterborne Outbreaks 17.10.3.1 E. coli 17.10.3.2 Giardia lamblia 17.10.3.3 Cryptosporidium 17.10.3.4 Legionella pneumophila 17.10.4 Mechanism of Pathogen Inactivation 17.10.5 Other Uses of Disinfectants in Water Treatment 17.10.5.1 Minimization of DBP Formation 17.10.5.2 Control of Nuisance Asiatic Clams and Zebra Mussels 17.10.5.3 Oxidation of Iron and Manganese 17.10.5.4 Prevention of Regrowth in the Distribution System and Maintenance of Biological Stability 17.10.5.5 Removal of Taste and Odors through Chemical Oxidation 17.10.5.6 Improvement of Coagulation and Filtration EfÞciency 17.10.5.7 Prevention of Algal Growth in Sedimentation Basins and Filters 17.10.5.8 Removal of Color 17.10.6 Types of DBPs and Disinfection Residuals 17.10.6.1 Disinfection By-Product Formation 17.10.6.2 DBP Control Strategies 17.10.6.3 CT Factor 17.10.7 Pathogen Inactivation vs. DBP Formation 17.10.8 Disinfectant Residual Regulatory Requirements 17.10.9 Summary of Current National Disinfection Practices 17.10.10 Summary of Methods of Disinfection 17.10.11 Chlorination 17.10.11.1 Chlorine Terms 17.10.11.2 Chlorine Chemistry 17.10.11.3 Breakpoint Chlorination © 2003 by CRC Press LLC
  23. 23. 17.10.11.4 Gas Chlorination 17.10.11.5 Hypochlorination 17.10.11.6 Determining Chlorine Dosage 17.10.11.7 Chlorine Generation 17.10.11.8 Primary Uses and Points of Application of Chlorine 17.10.11.9 Factors Affecting Chlorination 17.10.11.10 Measuring Chlorine Residual 17.10.11.11 Pathogen Inactivation and Disinfection EfÞcacy 17.10.11.12 Disinfection By-Products 17.10.11.13 Operational Considerations 17.10.11.14 Advantages and Disadvantagesof Chlorine Use 17.10.11.15 Chlorine Summary Table17.11 Arsenic Removal from Drinking Water 17.11.1 Arsenic and Water 17.11.2 Arsenic Removal Technologies 17.11.2.1 Prescriptive Processes 17.11.2.2 Adsorptive Processes 17.11.2.3 Membrane Processes 17.11.2.4 Alternative Technologies17.12 Who is Ultimately Responsible for Drinking Water Quality?17.13 Chapter Review Questions and ProblemsReferencesChapter 18 Wastewater Treatment18.1 Wastewater Operators 18.1.1 The Wastewater Treatment Process: The Model18.2 Wastewater Terminology and DeÞnitions 18.2.1 Terminology and DeÞnitions18.3 Measuring Plant Performance 18.3.1 Plant Performance and EfÞciency 18.3.2 Unit Process Performance and EfÞciency 18.3.3 Percent Volatile Matter Reduction in Sludge18.4 Hydraulic Detention Time 18.4.1 Detention Time in Days 18.4.2 Detention Time in Hours 18.4.3 Detention Time in Minutes18.5 Wastewater Sources and Characteristics 18.5.1 Wastewater Sources 18.5.1.1 Generation of Wastewater 18.5.2 ClassiÞcation of Wastewater 18.5.3 Wastewater Characteristics 18.5.3.1 Physical Characteristics 18.5.3.2 Chemical Characteristics 18.5.3.3 Biological Characteristics and Processes18.6 Wastewater Collection Systems 18.6.1 Gravity Collection System 18.6.2 Force Main Collection System 18.6.3 Vacuum System 18.6.4 Pumping Stations 18.6.4.1 Wet Well–Dry Well Pumping Stations 18.6.4.2 Wet Well Pumping Stations 18.6.4.3 Pneumatic Pumping Stations 18.6.4.4 Pumping Station Wet Well Calculations © 2003 by CRC Press LLC
  24. 24. 18.7 Preliminary Treatment 18.7.1 Screening 18.7.1.1 Manually Cleaned Screens 18.7.1.2 Mechanically Cleaned Screens 18.7.1.3 Safety 18.7.1.4 Screenings Removal Computations 18.7.2 Shredding 18.7.2.1 Comminution 18.7.2.2 Barminution 18.7.3 Grit Removal 18.7.3.1 Gravity and Velocity Controlled Grit Removal 18.7.3.2 Grit Removal Calculations 18.7.4 Preaeration 18.7.4.1 Operational Observations, Problems, and Troubleshooting 18.7.5 Chemical Addition 18.7.5.1 Operational Observations, Problems, and Troubleshooting 18.7.6 Equalization 18.7.6.1 Operational Observations, Problems, andTroubleshooting 18.7.7 Aerated Systems 18.7.8 Cyclone Degritter 18.7.9 Preliminary Treatment Sampling and Testing 18.7.10 Other Preliminary Treatment Process Control Calculations18.8 Primary Treatment (Sedimentation) 18.8.1 Process Description 18.8.1.1 Overview of Primary Treatment 18.8.2 Types of Sedimentation Tanks 18.8.2.1 Septic Tanks 18.8.2.2 Two-Story (Imhoff) Tank 18.8.2.3 Plain Settling Tanks (ClariÞers) 18.8.3 Operator Observations, Process Problems, and Troubleshooting 18.8.3.1 Primary ClariÞcation: Normal Operation 18.8.3.2 Primary ClariÞcation: Operational Parameters (Normal Observations) 18.8.4 Process Control Calculations 18.8.4.1 Percent Removal 18.8.4.2 Detention Time 18.8.4.3 Surface Loading Rate (Surface Settling Rate and Surface Overßow Rate) 18.8.4.4 Weir Overßow Rate (Weir Loading Rate) 18.8.4.5 Sludge Pumping 18.8.4.6 BOD and Suspended Solids Removal 18.8.5 Problem Analysis 18.8.6 Efßuent from Settling Tanks18.9 Secondary Treatment 18.9.1 Treatment Ponds 18.9.1.1 Types of Ponds 18.9.1.2 Process Control Calculations (Stabilization Ponds) 18.9.2 Trickling Filters 18.9.2.1 Trickling Filter DeÞnitions 18.9.2.2 Trickling Filter Equipment 18.9.2.3 Filter ClassiÞcations 18.9.2.4 Standard Operating Procedures 18.9.2.5 General Process Description 18.9.2.6 Operator Observations, Process Problems, and Troubleshooting 18.9.2.7 Process Calculations © 2003 by CRC Press LLC
  25. 25. 18.9.3 Rotating Biological Contactors 18.9.3.1 RBC Equipment 18.9.3.2 RBC Operation 18.9.3.3 RBC: Expected Performance 18.9.3.4 Operator Observations, Process Problems, and Troubleshooting 18.9.3.5 RBC: Process Control Calculations18.10 Activated Sludge 18.10.1 Activated Sludge Terminology 18.10.2 Activated Sludge Process: Equipment 18.10.2.1 Aeration Tank 18.10.2.2 Aeration 18.10.2.3 Settling Tank 18.10.2.4 Return Sludge 18.10.2.5 Waste Sludge 18.10.3 Overview of Activated Sludge Process 18.10.4 Activated Sludge Process: Factors Affecting Operation 18.10.4.1 Growth Curve 18.10.5 Activated Sludge Formation 18.10.6 Activated Sludge: Performance-Controlling Factors 18.10.6.1 Aeration 18.10.6.2 Alkalinity 18.10.6.3 Nutrients 18.10.6.4 pH 18.10.6.5 Temperature 18.10.6.6 Toxicity 18.10.6.7 Hydraulic Loading 18.10.6.8 Organic Loading 18.10.7 Activated Sludge ModiÞcations 18.10.7.1 Conventional Activated Sludge 18.10.7.2 Step Aeration 18.10.7.3 Complete Mix 18.10.7.4 Pure Oxygen 18.10.7.5 Contact Stabilization 18.10.7.6 Extended Aeration 18.10.7.7 Oxidation Ditch 18.10.8 Activated Sludge: Process Control Parameters 18.10.8.1 Alkalinity 18.10.8.2 Dissolved Oxygen 18.10.8.3 pH 18.10.8.4 Mixed Liquor Suspended Solids, Mixed Liquor Volatile Suspended Solids, and Mixed Liquor Total Suspended Solids 18.10.8.5 Return Activated Sludge Rate and Concentration 18.10.8.6 Waste Activated Sludge Flow Rate 18.10.8.7 Temperature 18.10.8.8 Sludge Blanket Depth 18.10.9 Operational Control Levels 18.10.9.1 Inßuent Characteristics 18.10.9.2 Industrial Contributions 18.10.9.3 Process Sidestreams 18.10.9.4 Seasonal Variations 18.10.9.5 Control Levels at Start-Up 18.10.10 Operator Observations: Inßuent and Aeration Tank 18.10.10.1 Visual Indicators: Inßuent and Aeration Tank 18.10.10.2 Final Settling Tank (ClariÞer) Observations © 2003 by CRC Press LLC
  26. 26. 18.10.11 Process Control Testing and Sampling 18.10.11.1 Aeration Inßuent Sampling 18.10.11.2 Aeration Tank 18.10.11.3 Settling Tank Inßuent 18.10.11.4 Settling Tank 18.10.11.5 Settling Tank Efßuent 18.10.11.6 Return Activated Sludge and Waste Activated Sludge 18.10.12 Process Control Adjustments 18.10.13 Troubleshooting Operational Problems 18.10.14 Process Control Calculations 18.10.14.1 Settled Sludge Volume 18.10.14.2 Estimated Return Rate 18.10.14.3 Sludge Volume Index 18.10.14.4 Waste Activated Sludge 18.10.14.5 Food to Microorganism Ratio (F:M Ratio) 18.10.14.6 Mean Cell Residence Time (MCRT) 18.10.14.7 Mass Balance 18.10.15 Solids Concentration: Secondary ClariÞer 18.10.16 Activated Sludge Process Record Keeping Requirements18.11 Disinfection of Wastewater 18.11.1 Chlorine Disinfection 18.11.1.1 Chlorination Terminology 18.11.1.2 Wastewater Chlorination: Facts and Process Description 18.11.1.3 Chlorination Equipment 18.11.1.4 Chlorination: Operation 18.11.1.5 Troubleshooting Operational Problems 18.11.1.6 Dechlorination 18.11.1.7 Chlorination Environmental Hazards and Safety 18.11.1.8 Chlorine: Safe Work Practice 18.11.1.9 Chlorination Process Calculations 18.11.2 UV Irradiation 18.11.3 Ozonation 18.11.4 Bromine Chloride 18.11.5 No Disinfection18.12 Advanced Wastewater Treatment 18.12.1 Chemical Treatment 18.12.1.1 Operation, Observation, and Troubleshooting Procedures 18.12.2 Microscreening 18.12.2.1 Operation, Observation, and Troubleshooting Procedures 18.12.3 Filtration 18.12.3.1 Filtration Process Description 18.12.3.2 Operation, Observation, and Troubleshooting Procedures 18.12.4 Biological NitriÞcation 18.12.4.1 Operation, Observation, and Troubleshooting Procedures 18.12.5 Biological Denitrifcation 18.12.5.1 Observation, Operation, and Troubleshooting Procedures 18.12.6 Carbon Adsorption 18.12.6.1 Operation, Observation, and Troubleshooting Procedures 18.12.7 Land Application 18.12.7.1 Types or Modes of Land Application 18.12.8 Biological Nutrient Removal18.13 Solids (Sludge or Biosolids) Handling 18.13.1 Sludge: Background Information 18.13.1.1 Sources of Sludge 18.13.1.2 Sludge Characteristics © 2003 by CRC Press LLC
  27. 27. 18.13.1.3 Sludge Pumping Calculations 18.13.1.4 Sludge Treatment: An Overview 18.13.2 Sludge Thickening 18.13.2.1 Gravity Thickening 18.13.2.2 Flotation Thickening 18.13.2.3 Solids Concentrators 18.13.3 Sludge Stabilization 18.13.3.1 Aerobic Digestion 18.13.3.2 Anaerobic Digestion 18.13.3.3 Other Sludge Stabilization Processes 18.13.4 Sludge Dewatering 18.13.4.1 Sand Drying Beds 18.13.4.2 Rotary Vacuum Filtration 18.13.4.3 Pressure Filtration 18.13.4.4 Centrifugation 18.13.4.5 Sludge Incineration 18.13.4.6 Land Application of Biosolids18.14 Permits, Records, and Reports 18.14.1 DeÞnitions 18.14.2 NPDES Permits 18.14.2.1 Reporting 18.14.2.2 Sampling and Testing 18.14.2.3 Efßuent Limitations 18.14.2.4 Compliance Schedules 18.14.2.5 Special Conditions 18.14.2.6 Licensed Operator Requirements 18.14.2.7 Chlorination or Dechlorination Reporting 18.14.2.8 Reporting Calculations18.15 Chapter Review Questions and ProblemsReferencesAppendix A Answers to Chapter Review Questions and ProblemsAppendix B Formulae © 2003 by CRC Press LLC
  28. 28. PART IWater and Wastewater Operations:An Overview© 2003 by CRC Press LLC
  29. 29. Problems Facing Water and 1 Wastewater Treatment Operations What is of all things most yielding, 1. Protection against protozoan and virus contam- Can overcome that which is most hard, ination Being substanceless, it can enter in 2. Implementation of the multiple barrier approach even where there is no crevice. to microbial control 3. New requirements of the Ground Water Disin- That is how I know the value fection Rule, the Total Coliform Rule and of action which is actionless. Distribution System, and the Lead and Copper Rule Lao Tzu, 5th Century B.C. 4. Regulations for trihalomethanes and disinfec- tion by-products (DBPs)1.1 INTRODUCTION We discuss this important shift momentarily but firstAlthough not often thought of as a commodity (or, for that it is important to abide by Voltaire’s advice: that is, “Ifmatter, not thought about at all), water is a commodity — you wish to converse with me, please define your terms.”a very valuable commodity. In this text, it is our position For those not familiar with the term paradigm, it canthat with the passage of time, potable water will become be defined in the following ways. A paradigm is the con-even more valuable. Moreover, with the passage of even sensus of the scientific community — “concrete problemmore time, potable water will be even more valuable than solutions that the profession has come to accept.”1 Thomaswe might imagine. It may be possibly comparable in pric- Kuhn coined the term paradigm. He outlined it in termsing, gallon for gallon, to what we pay for gasoline, or even of the scientific process. He felt that “one sense of para-more. digm, is global, embracing all the shared commitments of Earth was originally allotted a finite amount of water — a scientific group; the other isolates a particularly impor-we have no more or no less than that original allotment tant sort of commitment and is thus a subset of the first.”1today. It logically follows that, in order to sustain life as The concept of paradigm has two general levels. The firstwe know it, we must do everything we can to preserve is the encompassing whole, the summation of parts. Itand protect our water supply. We also must purify and consists of the theories, laws, rules, models, concepts, andreuse the water we presently waste (i.e., wastewater). definitions that go into a generally accepted fundamental theory of science. Such a paradigm is global in character. The other level of paradigm is that it can also be just one1.2 THE PARADIGM SHIFT of these laws, theories, models, etc. that combine to for- mulate a global paradigm. These have the property ofHistorically, the purpose of water supply systems has been being local. For instance, Galileo’s theory that the earthto provide pleasant drinking water that is free of disease rotated around the sun became a paradigm in itself, namelyorganisms and toxic substances. In addition, the purpose a generally accepted law in astronomy. Yet, on the otherof wastewater treatment has been to protect the health and hand, his theory combined with other local paradigms inwell being of our communities. Water and wastewater areas such as religion and politics to transform culture. Atreatment operations have accomplished this goal by paradigm can also be defined as a pattern or point of view(1) prevention of disease and nuisance conditions; that determines what is seen as reality.(2) avoidance of contamination of water supplies and nav- We use the latter definition in this text.igable waters; (3) maintenance of clean water for survival A paradigm shift is defined as a major change in theof fish, bathing, and recreation; and (4) generally conser- way things are thought about, especially scientifically. Oncevation of water quality for future use. a problem can no longer be solved in the existing paradigm, The purpose of water supply systems and wastewater new laws and theories emerge and form a new paradigm,treatment processes has not changed. However, primarily overthrowing the old if it is accepted. Paradigm shifts arebecause of new regulations the paradigm has shifted. the “occasional, discontinuous, revolutionary changes inThese include: tacitly shared points of view and preconceptions.”2 Simply, © 2003 by CRC Press LLC
  30. 30. a paradigm shift represents “a profound change in the Source Protectionthoughts, perceptions, and values that form a particularvision of reality.”3 For our purposes, we use the term ↓paradigm shift to mean a change in the way things are Optimization of Treatment Processunderstood and done. Trained & Certified Plant Operators1.2.1 A CHANGE IN THE WAY THINGS ARE ↓ Sound Distribution System Management UNDERSTOOD AND DONE A Second Dose of DisinfectantIn water supply systems, the historical focus, or traditional ↓approach, has been to control turbidity, iron and manga- Cross-Connection Controlnese, taste and odor, color, and coliforms. New regulationsprovided new focus, and thus a paradigm shift. Today the ↓traditional approach is no longer sufficient. Providing Continuous Monitoring & Testingacceptable water has become more sophisticated and FIGURE 1.1 Multiple-barrier approach.costly. In order to meet the requirements of the new para- SDWA, passed in 1974, amended in 1986, and reau-digm, a systems approach must be employed. In the sys- thorized in 1996, gives the U.S. Environmental Protectiontems approach, all components are interrelated. What Agency (EPA) the authority to set drinking water stan-affects one impacts others. The focus has shifted to mul- dards. This document is important for many reasons, buttiple requirements (i.e., new regulations require the pro- is even more important because it describes how the EPAcess to be modified or the plant upgraded). establishes these standards. To illustrate the paradigm shift in the operation of Drinking water standards are regulations that EPA setswater supply systems, let us look back on the traditional to control the level of contaminants in the nation’s drinkingapproach of disinfection. Disinfection was used in water water. These standards are part of SDWA’s multiple-barrierto destroy harmful organisms. It is still used in water to approach to drinking water protection (see Figure 1.1).destroy harmful organisms, but is now only one part of As shown in Figure 1.1, the multiple barrier approachthe multiple-barrier approach. Moreover, disinfection has includes the following elements:traditionally been used to treat for coliforms only. Cur-rently, because of the paradigm shift, disinfection now 1. Assessing and protecting drinking water(and in the future) is used against coliforms, Legionella, sources — This means doing everything possi-Giardia, Cryptosporidium, and others. Another example ble to prevent microbes and other contaminantsof the traditional vs. current practices is seen in the tradi- from entering water supplies. Minimizingtional approach to particulate removal in water to lessen human and animal activity around our water-turbidity and improve aesthetics. Current practice is still sheds is one part of this barrier.to decrease turbidity to improve aesthetics, but now micro- 2. Optimizing treatment processes — This pro-bial removal plus disinfection is practical. vides a second barrier and usually means filter- Another significant factor that contributed to the par- ing and disinfecting the water. It also meansadigm shift in water supply systems was the introduction making sure that the people who are responsibleof the Surface Water Treatment Rule (SWTR) in 1989. for our water are properly trained and certifiedSWTR requires water treatment plants to achieve 99.9% and knowledgeable of the public health issues(3 log) removal activation/inactivation of Giardia and involved.99.99% (4 log) removal/inactivation of viruses. SWTR 3. Ensuring the integrity of distribution systems —applies to all surface waters and ground waters under This consists of maintaining the quality ofdirect influence. water as it moves through the system on its way to the customer’s tap.1.3 MULTIPLE-BARRIER CONCEPT 4. Effecting correct cross-connection control pro- cedures — This is a critical fourth element inOn August 6, 1996, during the Safe Drinking Water Act the barrier approach. It is critical because the(SDWA) Reauthorization signing ceremony, President Bill greatest potential hazard in water distributionClinton stated, “A fundamental promise we must make to systems is associated with cross-connections toour people is that the food they eat and the water they nonpotable waters. There are many connectionsdrink are safe.” No rational person could doubt the impor- between potable and nonpotable systems —tance of the promise made in this statement. every drain in a hospital constitutes such a © 2003 by CRC Press LLC
  31. 31. connection, but cross-connections are those hidden part out of services delivered by water and waste- through which backflow can occur.4 water professionals. 5. Continuous monitoring and testing of the water Water service professionals provide water for typical before it reaches the tap — Monitoring water urban domestic and commercial uses, eliminate wastes, quality is a critical element in the barrier protect the public health and safety, and help control many approach. It should include having specific pro- forms of pollution. Wastewater service professionals treat cedures to follow should potable water ever fail the urban wastestream to remove pollutants before dis- to meet quality standards. charging the effluent into the environment. Water and wastewater treatment services are the urban circulatory With the involvement of EPA, local governments, system.6 In addition, like the human circulatory system,drinking water utilities, and citizens, these multiple barri- the urban circulatory system is less than effective if flowers ensure that the tap water in the U.S. and territories is is not maintained.safe to drink. Simply, in the multiple-barrier concept, we Maintaining flow is what water and wastewater oper-employ a holistic approach to water management that ations is all about. This seems easy enough; water hasbegins at the source and continues with treatment, through been flowing literally for eons. However, this is not to saydisinfection and distribution. that water and wastewater operations are not without prob- lems and/or challenges. The dawn of the 21st century brought with it, for many of us, aspirations of good things1.3.1 MULTIPLE-BARRIER APPROACH: ahead in the constant struggle to provide quality food and WASTEWATER OPERATIONS water for humanity. However, the only way in which weNot shown in Figure 1.1 is the fate of the used water. What can hope to accomplish this is to stay on the cutting edge of technology and to face all challenges head on. Somehappens to the wastewater produced? Wastewater is of these other challenges are addressed in the followingtreated via the multiple-barrier treatment train, which is sections.the combination of unit processes used in the system. Theprimary mission of the wastewater treatment plant (andthe operator/practitioner) is to treat the wastestream to a 1.4 MANAGEMENT PROBLEMS FACINGlevel of purity acceptable to return it to the environment WATER AND WASTEWATER OPERATIONSor for immediate reuse (i.e., reuse in such applications asirrigation of golf courses, etc.). Problems come and go, shifting from century to century, Water and wastewater operators maintain a continuous decade to decade, year to year, and site to site. They rangeurban water cycle on a daily basis. B.D. Jones sums up from the problems caused by natural forces (storms, earth-this point as follows: quakes, fires, floods, and droughts) to those caused by social forces, currently including terrorism. Delivering services is the primary function of municipal In general, five areas are of concern to many water government. It occupies the vast bulk of the time and effort and wastewater management personnel. of most city employees, is the source of most contacts that citizens have with local governments, occasionally 1. Complying with regulations and coping with becomes the subject of heated controversy, and is often new and changing regulations surrounded by myth and misinformation. Yet, service deliv- ery remains the “hidden function” of local government.5 2. Maintaining infrastructure 3. Privatization and/or reengineering In Handbook of Water and Wastewater Treatment 4. BenchmarkingPlant Operations, we focus on sanitary (or environmental) 5. Upgrading securityservices (excluding solid-waste disposal) — water andwastewater treatment — because they have been and 1.4.1 COMPLIANCE WITH NEW, CHANGING,remain indispensable for the functioning and growth of AND EXISTING REGULATIONS7cities. Next to air, water is the most important life-sustain-ing product on earth. Yet it is its service delivery (and all Adapting the workforce to the challenges of meetingthat it entails) that remains a “hidden function” of local changing regulations and standards for both water andgovernment.5 This hidden function is what this text is all wastewater treatment is a major concern. As mentioned,about. We present our discussion in a completely new and drinking water standards are regulations that EPA sets tounique dual manner — in what we call the new paradigm control the level of contaminants in the nation’s drinkingshift in water management and in the concept of the mul- water. Again, these standards are part of SDWA’s multiple-tiple barrier approach. Essentially, the Handbook takes the barrier approach to drinking water protection. © 2003 by CRC Press LLC
  32. 32. There are two categories of drinking water standards: 1.4.2 MAINTAINING INFRASTRUCTURE 1. A National Primary Drinking Water Regulation During the 1950s and 1960s, the U.S. government encour- (primary standard) — This is a legally enforce- aged the prevention of pollution by providing funds for able standard that applies to public water systems. the construction of municipal wastewater treatment plants, Primary standards protect drinking water quality water-pollution research, and technical training and assis- by limiting the levels of specific contaminants tance. New processes were developed to treat sewage, that can adversely affect public health and are analyze wastewater, and evaluate the effects of pollution known or anticipated to occur in water. They on the environment. In spite of these efforts, expanding take the form of Maximum Contaminant Levels population and industrial and economic growth caused the or Treatment Techniques. pollution and health difficulties to increase. 2. A National Secondary Drinking Water Regula- In response to the need to make a coordinated effort tion (secondary standard) — This is a nonen- to protect the environment, the National Environmental forceable guideline regarding contaminants that Policy Act was signed into law on January 1, 1970. In may cause cosmetic effects (e.g., skin or tooth December of that year, a new independent body — EPA — discoloration) or aesthetic effects (e.g., taste, was created to bring under one roof all of the pollution- odor, or color) in drinking water. USEPA rec- control programs related to air, water, and solid wastes. ommends secondary standards to water systems, In 1972, the Water Pollution Control Act Amendments but does not require systems to comply. How- expanded the role of the federal government in water ever, states may choose to adopt them as pollution control and significantly increased federal fund- enforceable standards. This information ing for construction of wastewater treatment plants. focuses on national primary standards. Many of the wastewater treatment plants in operation today are the result of federal grants made over the years. Drinking water standards apply to public water sys- For example, because of the 1977 Clean Water Acttems that provide water for human consumption through Amendment to the Federal Water Pollution Control Actat least 15 service connections or regularly serve at least of 1972 and the 1987 Clean Water Act Reauthorization25 individuals. Public water systems include municipal Bill, funding for wastewater treatment plants was provided.water companies, homeowner associations, schools, busi- Many large sanitation districts, with their multiplenesses, campgrounds and shopping malls. plant operations, and an even larger number of single plant More recent requirements, including the Clean Water operations in smaller communities in operation today are aAct Amendments that went into effect in February 2001, result of these early environmental laws. Because of theserequire water treatment plants to meet tougher standards. laws, the federal government provided grants of severalThey have presented new problems for treatment facilities hundred million dollars to finance construction of waste-to deal with and have offered some possible solutions to water treatment facilities throughout the country.the problems of meeting the new standards. These regula- Many of these locally or federally funded treatmenttions provide for communities to upgrade existing treatment plants are aging; based on our experience, we rate some assystems, replacing aging and outdated infrastructure with dinosaurs. The point is many facilities are facing problemsnew process systems. Their purpose is to ensure that facil- caused by aging equipment, facilities, and infrastructure.ities are able to filter out higher levels of impurities from Complicating the problems associated with natural agingdrinking water, reducing the health risk from bacteria, is the increasing pressure on inadequate older systems toprotozoa, and viruses, and that they are able to decrease meet demands of increased population and urban growth.levels of turbidity and reduce concentrations of chlorine Facilities built in the 1960s and 1970s are now 30 toby-products in drinking water. 40 years old; not only are they showing signs of wear and In regards to wastewater collection and treatment, the tear, but they simply were not designed to handle the levelNational Pollution Discharge Elimination System program of growth that has occurred in many municipalities.established by the Clean Water Act, issues permits that Regulations often necessitate a need to upgrade. Bycontrol wastewater treatment plant discharges. Meeting per- matching funds or providing federal money to cover somemit is always a concern for wastewater treatment managers of the costs, municipalities can take advantage of a win-because the effluent discharged into water bodies affects dow of opportunity to improve their facility at a lowerthose downstream of the release point. Individual point direct cost to the community. Those federal dollars, ofsource dischargers must use the best available technology course, do come with strings attached; they are to be spentto control the levels of pollution in the effluent they dis- on specific projects in specific areas. On the other hand,charge into streams. As systems age, and best available many times new regulatory requirements are put in placetechnology changes, meeting permit with existing equip- without the financial assistance needed to implement.ment and unit processes becomes increasingly difficult. When this occurs, either the local community ignores the © 2003 by CRC Press LLC
  33. 33. new requirements (until caught and forced to comply) or Our experience has shown that few words conjure upthey face the situation and implement through local tax more fear among municipal plant managers than privati-hikes to pay the cost of compliance. zation or reengineering. Privatization means allowing An example of how a change in regulations can force private enterprise to compete with government in providingthe issue is demonstrated by the demands made by the public services, such as water and wastewater operations.Occupational Safety and Health Administration (OSHA) Existing management, on the other hand, can accomplishand EPA in their Process Safety Management (PSM)/Risk reengineering internally or it can be used (and usually is)Management Planning (RMP) regulations. These regula- during the privatization process. Reengineering is the sys-tions put the use of elemental chlorine (and other listed tematic transformation of an existing system into a newhazardous materials) under scrutiny. Moreover, because form to realize quality improvements in operation, systemof these regulations, plant managers throughout the coun- capability, functionality, performance, or evolvability at atry are forced to choose which side of a double-edged lower cost, schedule, or risk to the customer.sword cuts their way the most. One edge calls for full Many on-site managers consider privatization and/orcompliance with the regulations (analogous to stuffing the reengineering schemes threatening. In the worse case sce-regulation through the eye of a needle). The other edge nario, a private contractor could bid the entire staff out ofcalls for substitution. This means replacing elemental their jobs. In the best case, privatization and/or re-engi-chlorine with a nonlisted hazardous chemical (e.g., neering is often a very real threat that forces on-sitehypochlorite) or a physical (ultraviolet irradiation) disin- managers into workforce cuts, improving efficiency andfectant — a very costly undertaking either way. cutting costs. (At the same time, on-site managers work to ensure the community receives safe drinking water andNote: Many of us who have worked in water and the facility meets standards and permits. This is done with wastewater treatment for years characterize fewer workers and without injury or accident to workers, PSM and RMP as the elemental chlorine killer. the facility, or the environment.) You have probably heard the old saying: “If you There are a number of reasons causing local officials can’t do away with something in one way, then to take a hard look at privatization and/or re-engineering. regulate it to death.” 1. Decaying infrastructures — Many water andNote: Changes resulting because of regulatory pressure wastewater operations include water and waste- sometimes mean replacing or changing existing water infrastructures that date back to the early equipment, increased chemical costs (e.g., sub- 1900s. The most recent systems were built with stituting hypochlorite for chlorine typically federal funds during the 1970s, and even these increases costs threefold), and could easily now need upgrading or replacing. The EPA involve increased energy and personnel costs. recently estimated that the nation’s 75,000+ Equipment condition, new technology, and drinking water systems alone would require financial concerns are all considerations when more than $100 billion in investments over the upgrades or new processes are chosen. In addi- next 20 years. Wastewater systems will require tion, the safety of the process must be considered a similar level of investment. because of the demands made by EPA and 2. Mandates — The federal government has OSHA. The potential of harm to workers, the reduced its contributions to local water and community, and the environment are all under wastewater systems over the past 30 years, study, as are the possible long-term effects of while at the same time imposing stricter water chlorination on the human population. quality and effluent standards under the Clean Water Act and SDWA. Moreover, as previously1.4.3 PRIVATIZING AND/OR REENGINEERING8 mentioned, new unfunded mandated safety reg- ulations, such as OSHA’s PSM and EPA’s RMP,As mentioned, water and wastewater treatment operations are expensive to implement using local sourcesare undergoing a new paradigm shift. We explained that of revenues or state revolving loan funds.this paradigm shift focused on the holistic approach to 3. Hidden function — Earlier we stated thattreating water. The shift is, however, more inclusive. It much of the work of water and wastewater treat-also includes thinking outside the box. In order to remain ment is a hidden function. Because of this lackefficient and therefore competitive in the real world of of visibility, it is often difficult for local officialsoperations, water and wastewater facilities have either to commit to making the necessary investmentsbought into the new paradigm shift, or been forcibly in community water and wastewater systems.“shifted” to doing other things (often these other things Simply, the local politicians lack the politicalhave little to do with water and wastewater operations). will — water pipes and interceptors are not © 2003 by CRC Press LLC
  34. 34. Start → Plan →Research →Observe → Analyze → AdaptFIGURE 1.2 Benchmarking process. visible and not perceived as immediately criti- performance vs. best-in-class operations, and using the cal for adequate funding. It is easier for elected analysis to meet and exceed the best in class. officials to ignore them in favor of expenditures of more visible services, such as police and fire. What benchmarking is: Additionally, raising water and sewage rates to cover operations and maintenance is not always 1. Benchmarking vs. best practices gives water effected because it is an unpopular move for and wastewater operations a way to evaluate elected officials. This means that water and their operations overall. sewer rates do not adequately cover the actual a. How effective cost of providing services in many municipalities. b. How cost effective 2. Benchmarking shows plants both how well In many locations throughout the U.S., expenditures their operations stack up, and how well thoseon water and wastewater services are the largest facing operations are implemented.local governments today. (This is certainly the case for 3. Benchmarking is an objective-setting process.those municipalities struggling to implement the latest 4. Benchmarking is a new way of doing business.storm water requirements). Thus, this area presents a great 5. Benchmarking forces an external view toopportunity for cost savings. Through privatization, water ensure correctness of objective-setting.and wastewater companies can take advantage of advanced 6. Benchmarking forces internal alignment totechnology, more flexible management practices, and achieve plant goals.streamlined procurement and construction practices to 7. Benchmarking promotes teamwork by direct-lower costs and make the critical improvements more ing attention to those practices necessary toquickly. remain competitive.1.4.4 BENCHMARKING Potential results of benchmarking:Primarily out of self-preservation (to retain their lucrative 1. Benchmarking may indicate direction ofpositions), many utility directors work against the trend required change rather than specific metricsto privatize water, wastewater, and other public operations. a. Costs must be reducedUsually the real work to prevent privatization is delegated b. Customer satisfaction must be increasedto the individual managers in charge of each specific oper- c. Return on assets must be increasedation. Moreover, it can be easily seen that working against d. Improved maintenanceprivatization by these local managers is also in their own e. Improved operational practicesself-interest and in the interest of their workers; their jobs 2. Best practices are translated into operationalmay be at stake. units of measure. The question is, of course, how does one go aboutpreventing his water and wastewater operation from being Targets:privatized? The answer is rather straightforward and clear:Efficiency must be improved at reduced cost. In the real 1. Consideration of available resources convertsworld, this is easier said than done, but is not impossible. benchmark findings to targets.For example, for those facilities under Total Quality Man- 2. A target represents what can realistically beagement (TQM), the process can be much easier. accomplished in a given timeframe. The advantage TQM offers the plant manager is the 3. A target can show progress toward benchmarkvariety of tools to help plan, develop, and implement water practices and metrics.and wastewater efficiency measures. These tools include 4. Quantification of precise targets should beself-assessments, statistical process control, International based on achieving benchmark.Organization for Standards 9000 and 14000, process anal-ysis, quality circle, and benchmarking (see Figure 1.2). Note: Benchmarking can be performance based, pro- Our focus in this text is on use of the benchmarking cess based, or strategy based and can comparetool to improve water and wastewater operation’s efficiency. financial or operational performance measures,Benchmarking is a process for rigorously measuring your methods or practices, or strategic choices. © 2003 by CRC Press LLC

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