Twort's water supply - GBV · 4.1 Groundwater, Aquifers andTheirManagement 117 4.2 Yield...

Twort's Water Supply

Seventh Edition

Malcolm J. Brandt

BSc, FICE, FCIWEM, MlWater

K. Michael Johnson

BSc, FICE, FCIWEM

Andrew J. ElphinstonBSc, MIChemE, MCIWEM

Don D. RatnayakaBSc, DIC, MSc, FIChemE, FCIWEM

AMSTERDAM • BOSTON • HEIDELBERG • LONDON

NEW YORK • OXFORD • PARIS • SAN DIEGO

SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO

mELSEVIER Butterworth-Heinemann is an imprint of Elsevier

Contents

Authors' Biographic Details xxv

Foreword xxvn

Preface XX1X

Abbreviations for Organizations xxxi

Contributing Authors, Reviewers and Advisors xxxiii

CHAPTER 1 The Demand for Potable Water 1

1.1 Categories of Consumption 1

1.2 Levels of Total Consumption 2

1.3 Domestic Demand 3

1.4 Standpipe Demand 9

1.5 Suggested Domestic Design Allowances 10

1.6 Non-Domestic Demand 12

1.7 Public and Miscellaneous Use of Water 15

1.8 Water Losses 15

1.9 Real Losses (Leakage) From 24-Hour Supply Systems 20

1.10 Supply Pipe Leakage and Consumer Wastage 22

1.11 Minimum Night Flow as Indicator of Leakage and Wastage 23

1.12 Variations in Demand (Peaking Factors) 24

1.13 Growth Trends of Consumption and Forecasting Future Demand 25

1.14 Water Conservation and Demand Management 26

1.15 The Question of Metering Domestic Supplies in the UK 29

1.16 Effect of Price on Water Demand 30

1.17 Assessing Future Demand in Developing Countries 31

1.18 Consumption Surveys 32

1.19 Test-Metering In-House Domestic Consumption 33

References 35

CHAPTER 2 Water Supply Regulation, Protection, Organizationand Financing 37

Development, Regulation and Protection 37

2.1 Control of Public Water Supplies 37

2.2 Control of Abstractions 38

2.3 Public Water Supplies in the USA 38

2.4 Public Water Supplies in Mainland Europe 40

2.5 Public Water Supplies in the England and Wales 42

2.6 Public Water Supplies in Scotland and Northern Ireland 47

V

vi Contents

Organization 48

2.7 Organization of a Water Utility 48

2.8 Staffing Levels 50

Project Appraisal and Financing of Capital Works 50

2.9 Appraisal Requirements 50

2.10 Comparison of Proposed Capital Projects 51

2.11 Comments on the Use of Discounting 55

2.12 Sustainability, Resilience and Engineering Choices 55

2.13 Financing of Capital Works 56

2.14 Depreciation and Asset Management Planning 57

2.15 Private Sector Participation in Water Supply 57

2.16 Private Sector Operation Agreements 58

2.17 Charging for Public Water Supplies 59

2.18 Comparison of Charges for Water and Other Data 61

References 62

CHAPTER 3 Hydrology and Surface Supplies 65

Part I Hydrological Considerations 65

3.1 Introduction 65

3.2 Catchment Areas 66

3.3 Data Collection 67

3.4 Streamflow Measurement 68

3.5 Rainfall Measurement 70

3.6 Evaporation and Transpiration Measurement 74

3.7 Soil Moisture Measurement 75

3.8 Catchment Losses 76

3.9 Streamflow Naturalization 78

3.10 Long-Term Average Catchment Run-Off 80

3.11 Minimum Rainfalls 81

3.12 Minimum Rates of Run-Off 82

3.13 Maximum Rainfalls 84

3.14 Maximum Run-Offs 85

Part II Yield of Surface Sources 88

3.15 Introduction, Definitions and Concepts 88

3.16 History of Yield Estimation in the UK 91

3.17 Methods of Yield Estimation - General 92

3.18 River Intake Yields 92

3.19 Yield of Direct Supply Impounding Reservoirs 95

3.20 Yield of a Pumped Storage Reservoir 99

3.21 Yield of Regulating Reservoirs 100

Contents vii

3.22 Yield of Catchwaters 102

3.23 Compensation Water 104

3.24 Yield of Water Resources Systems 105

3.25 Conjunctive Use and Operation Rules 106

3.26 Rainwater Collection Systems 108

3.27 The Likely Effects of Climate Change 109

References 113

CHAPTER 4 Groundwater Supplies 117

4.1 Groundwater, Aquifers and Their Management 117

4.2 Yield Uncertainties and Types of Abstraction Works 120

4.3 Potential Yield of an Aquifer 122

4.4 Assessment of Aquifer Characteristics 126

4.5 Groundwater Modelling 128

4.6 Test Pumping of Boreholes and Wells 131

4.7 Geophysical and Other Investigation Methods 134

4.8 Borehole Linings, Screens and Gravel Packs 135

4.9 Construction of Boreholes and Wells 138

4.10 Development and Refurbishing Boreholes and Wells 140

4.11 Pollution Protective Measures: Monitoring and Sampling 141

4.12 River Flow Augmentation by Groundwater Pumping 143

4.13 Artificial Recharge and Aquifer Storage Recharge 145

4.14 Groundwater Mining 147

4.15 Island Water Supplies 147

4.16 Collector Wells and Other Underground Water Developments 150

4.17 Borehole and Well Layouts 152

4.18 Choice of Pumping Plant for Wells and Boreholes 154

4.19 Environmental Impact Assessments 156

References 157

CHAPTER 5 Dams and Reservoirs 159

5.1 Introduction 159

5.2 Essential Reservoir Conditions 160

5.3 Watertightness 160

5.4 Strength and Durability of a Dam 163

5.5 Types of Dam:

164

Embankment Dams 165

5.6 Types of Design 165

5.7 Pore Pressure and Instrumentation in Earth Dams 166

5.8 Stability Analysis in Dam Design 168

viii Contents

5.9 Drainage Requirements for an Earth Dam 170

5.10 Surface Protection of Earth Dams 171

5.11 Rockfill and Composite Dams 173

Concrete and Masonry Dams 175

5.12 Gravity Dam Design 175

5.13 Gravity Dam Construction 177

5.14 Roller-Compacted Concrete Dams 178

5.15 Arch Dam Design 179

5.16 Buttress or Multiple Arch Dams 179

Flood and Discharge Provision 180

5.17 Design Flood Estimation 180

5.18 Spillway Flood Routing 184

5.19 Diversion During Construction 186

5.20 Flood Spillways 187

5.21 Draw-Off Arrangements 192

5.22 Seismic Considerations 193

Dam Regulation, Supervision and Inspection 193

5.23 Statutory Control Over Dam Safety in the UK 193

5.24 Dam Deterioration Signs 195

5.25 Reservoir Sedimentation 197

5.26 Environmental Considerations and Fish Passes 199

5.27 Statutory Consents and Requirements 200

5.28 Dam Incidents 200

References 202

CHAPTER 6 Intakes 205

6.1 Intake Function, Types and Main Considerations 205

General Considerations 206

6.2 Intake Capacity 206

6.3 Hydrology, Bathymetry and Hydraulics 206

6.4 Water Quality and Protection From Pollution 207

6.5 Abstraction Restrictions 207

6.6 Trash and Coarse Screens 208

6.7 Ice 209

6.8 Environmental Issues 210

6.9 Fish Behaviour 211

6.10 Fish Exclusion 212

6.11 Fish Protection Systems 214

6.12 Screening — Passive 214

6.13 Screening - Active 215

Contents ix

6.14 Biological Fouling of Screens and Intake Conduits 216

6.15 Headloss Through Screens 217

6.16 Coping With Water Level Variations 218

6.17 Interference With Other Users 219

6.18 Stability and Construction 219

6.19 Access for Operation and Maintenance 220

6.20 Intake Location and Siting 220

Intakes on Streams and Rivers 221

6.21 Sediment Transport 221

6.22 Sediment Exclusion and Removal 222

6.23 Flood Passage 222

6.24 Upland Intakes 223

6.25 Barrages and Weirs 224

6.26 Bankside Intakes 225

6.27 Radial Well Intakes 227

Intakes for Open Water 228

6.28 Shoreline Intakes 228

6.29 Intakes on Jetties or Pontoons 228

6.30 Tower Intakes 229

6.31 Offshore Intakes 229

References 232

CHAPTER 7 Chemistry, Microbiology and Biology of Water 235


Part I Significant Chemical and Physico-Chemical Parameters in Water 235

7.2 Acidity 235

7.3 Acrylamide 236

7.4 Algal Toxins 236

7.5 Alkalinity 236

7.6 Aluminium 237

7.7 Ammoniacal Compounds 238

7.8 Arsenic 238

7.9 Asbestos 239

7.10 Boron 239

7.11 Bromide and Iodide 239

7.12 Cadmium 240

7.13 Calcium '. 240

7.14 Carbon Dioxide 240

7.15 Chloride 240

7.16 Chlorinated Hydrocarbons 241

Contents

7.17 Chlorine Residual 241

7.18 Chromium 242

7.19 Colour 242

7.20 Copper 242

7.21 Corrosive Quality 243

7.22 Cyanide 243

7.23 Detergents 244

7.24 Disinfection By-Products (DBPs) 244

7.25 Electrical Conductivity and Dissolved Solids 246

7.26 Endocrine Disrupting Substances 246

7.27 Epichlorohydrin 247

7.28 Fluoride 247

7.29 Hardness 248

7.30 Hydrocarbons 248

7.31 Iron 249

7.32 Lead 249

7.33 Manganese 250

7.34 Nickel 251

7.35 Nitrate and Nitrite 251

7.36 Organic Matter, Biochemical Oxygen Demand (BOD)

and Chemical Oxygen Demand (COD) 253

7.37 Pesticides 254

7.38 pH Value or Hydrogen Ion 255

7.39 Phenols 256

7.40 Phosphates 256

7.41 Polynuclear Aromatic Hydrocarbons (PAHs) 256

7.42 Radioactive Substances 257

7.43 Selenium 258

7.44 Silica 258

7.45 Silver 259

7.46 Sodium 259

7.47 Sulphates 259

7.48 Suspended Solids 260

7.49 Taste and Odour 260

7.50 Turbidity 260

7.51 Zinc 261

Part II Water Quality Guidelines and Standards for Chemical

and Physical Parameters 261

7.52 Drinking Water Guidelines or Standards (Chemical and Physical) 261

Contents

7.53 Comment on the Application of Health-Related Standards 272

7.54 Sampling for Physical and Chemical Parameters 273

7.55 Raw Water Quality 276

7.56 Basic Priorities in Water Quality Control 279

7.57 Monitoring at Water Treatment Works 280

7.58 Methods of Chemical Analysis 281

7.59 Quality Assurance of Water Treatment Chemicals and Materials

in Contact With Drinking Water 282

Part III Water Microbiology 283

7.60 Diseases in Man That May Be Caused by Waterborne Bacteria

and Other Organisms 283

7.61 Bacterial Diseases 283

7.62 Other Bacteria 285

7.63 Protozoal Diseases 286

7.64 Viral Diseases 288

7.65 Microbiological Standards for Drinking Water 289

7.66 Use of Coliforms as an Indicator of Microbiological Pollution 291

7.67 Frequency of Sampling for Microbiological Parameters 291

7.68 Sampling for Routine Microbiological Parameters 292

7.69 Routine Tests for Bacterial Contamination of Water 294

7.70 Methodology for Microbiological Examination 296

7.71 Protozoal Examination 297

7.72 Virological Examination 298

7.73 Other Problem Organisms 298

Part IV Water Biology 299


7.75 Source Waters and Storage Reservoirs 300

7.76 Transfer Stages 303

7.77 Treatment Stages 304

7.78 Service Reservoirs and Distribution Systems 305

Part V New and Emerging Issues 306


7.80 Chemical Issues 306

7.81 Microbiological Issues 309

Part VI Water Safety Plans 311


7.83 Structure of a Water Safety Plan 312

7.84 Development of a Water Safety Plan 314

References 315

Contents

CHAPTER 8 Storage, Clarification and Chemical Treatment 323

8.1 Raw Water Storage 323

8.2 General Considerations for Water Treatment Plants 327

8.3 Microstrainers 327

Sedimentation and Settling Tanks 328

8.4 General Design Considerations 328

8.5 Plain Settling 329

8.6 Theory of Design of Tanks 331

8.7 Grit Tanks 332

Chemically Assisted Sedimentation or Clarification 332

8.8 Chemically Assisted Sedimentation 332

8.9 Chemical Mixing 332

8.10 Chemical Coagulation and Flocculation 336

8.11 Types of Flocculators 337

8.12 Factors Affecting Coagulation and Flocculation 339

8.13 Effect of Organic Content and Algae 341

Clarifiers 344

8.14 Horizontal Flow Clarifiers 344

8.15 Design Criteria 346

8.16 Sludge Blanket or Solids Contact Clarifiers 347

8.17 High Rate Clarifiers 350

8.18 Dissolved Air Flotation 354

8.19 Sludge Removal From Clarifiers 357

Coagulants and Coagulant Aids 359

8.20 Aluminium Coagulants 359

8.21 Iron Coagulants 361

8.22 Coagulant Aids and Polyelectrolytes 361

8.23 Rainwater Harvesting 363

References 363

CHAPTER 9 Water Filtration 367

Granular Media Filtration 367

9.1 Rapid Filtration — Introduction 367

9.2 Rapid Filtration - Mechanisms 367

9.3 Design and Construction of Rapid Gravity Filters 368

9.4 Backwashing 375

9.5 Operation of Filters 377

9.6 Construction and Operation of Pressure Filters 379

Multi-Layer and Other Methods of Filtration 381

9.7 Use of Anthracite Media 381

Contents xii

9.8 Use of Anthracite to Uprate Filters 383

9.9 Use of Granular Activated Carbon 383

9.10 Upward Flow Filtration 384

9.11 Direct Filtration 384

9.12 Filter Problems 386

Slow Sand Filtration 387

9.13 Introduction and History 387

9.14 Mode of Action of Slow Sand Filters 388

9.15 Construction and Cleaning of Slow Sand Filters 389

9.16 Use of Pre-Treatment With Slow Sand Filters 391

9.17 Limitations and Advantages of Slow Sand Filters 392

Membrane and Miscellaneous Filters 394

9.18 MF and UF Membrane Filtration 394

9.19 Miscellaneous Filters 399

Cryptosporidium Oocysts and Giardia Cysts Removal 401

9.20 Cryptosporidium 401

9.21 Giardia Cysts 402

References 403

CHAPTER 10 Specialized and Advanced Water Treatment Processes 407

Softening of Water 407

10.1 Hardness Compounds 407

10.2 Principal Methods of Softening 407

10.3 The Lime-Soda Process of Softening 408

10.4 Softening Plant 409

10.5 Water Softening by Crystallization 409

10.6 Stabilization After Softening 410

10.7 Base Exchange Softening 410

10.8 Plant for Ion Exchange (IX) Softening 411

10.9 Hardness and Alkalinity Removal by Ion Exchange 412

10.10 Demineralization of Water by Ion Exchange 412

Removal of Iron, Manganese and Other Metals 414

10.11 Iron and Manganese - General 414

10.12 Removal of Iron and Manganese From Underground Waters 414

10.13 Removal of Iron and Manganese From River and Reservoir Waters 418

10.14 Removal of Other Metals 419

10.15 Removal of Radionuclides 424

Defluoridation and Fluoridation 424

10.16 Defluoridation 424

10.17 Fluoridation 425

xiv Contents

Aeration 425

10.18 Purpose 425

10.19 Cascade Aerators 426

10.20 Packed Tower Aerators 428

10.21 Spray Aerators 429

10.22 Injection Aerators 429

10.23 Other Types of Aerators 430

Nitrate Removal 430

10.24 General 430

10.25 Ion Exchange (IX) Process for Nitrate Removal 431

10.26 Biological Process for Nitrate Removal 432

Removal of Ammonia 433

10.27 Chemical and Physical Methods 433

10.28 Biological Methods 433

Removal of Volatile Organic Compounds From Groundwater 435

10.29 General 435

10.30 Packed Tower Aerators 435

10.31 Adsorption and Chemical Oxidation 435

Taste and Odour Removal 436

10.32 Causes of Tastes and Odours 436

10.33 Methods of Removal of Tastes and Odours 437

Natural Organic Matter and Micropollutants Removal 439

10.34 General 439

10.35 Advanced Treatment Processes 440

10.36 Advanced Oxidation Processes 444

10.37 Colour Removal 446

Corrosion Causes and Prevention 447

10.38 Physical and Electrochemical Corrosion 447

10.39 Bacterial Corrosion 448

10.40 Corrosion Caused by Adverse Water Quality 449

10.41 Corrosiveness of Various Waters 451

10.42 Dezincification 453

Desalination 453


10.44 Ion Exchange 454

10.45 Electrodialysis 455

10.46 Reverse Osmosis and Nanofiltration 456

10.47 RO and NF Plant Design 460

10.48 Thermal Processes 463

10.49 Post Treatment 464

10.50 Effluent Disposal 465

Contents xv

10.51 The Costs of Desalination 465

References 467

CHAPTER 11 Disinfection of Water 475

11.1 Disinfectants Available 475

Disinfection Using Chlorine and Chloramines 475

11.2 Action of Chlorine 475

11.3 Chlorine Compounds Produced 476

11.4 Factors Relating to the Disinfection Efficiency of Chlorine 477

11.5 Chlorine Residual Concentration and Contact Time 478

11.6 Efficiency of Chlorine in Relation to Bacteria,

Enteric Viruses and Protozoa 481

11.7 Chlorination and the Production of DBPs 482

11.8 The Ammonia-Chlorine or Chloramination Process 483

11.9 Breakpoint Chlorination 484

11.10 Superchlorination 485

11.11 Typical Chlorine Dose 486

11.12 Dechlorination 486

11.13 Use of Ammonia 487

11.14 Hypochlorite Production on Site by Electrolysis 487

11.15 Testing for Chlorine 489

11.16 Use of Chlorine Dioxide 489

11.17 Sodium Hypochlorite Solution 491

11.18 Calcium Hypochlorite 491

Disinfection Using Ozone 491

11.19 Action of Ozone 491

11.20 Production of Ozone 493

11.21 Ozone Dissolution and Contact 496

11.22 Ozone Safety 498

Disinfection Using Ultraviolet Radiation 498

11.23 UV Disinfection 498

11.24 UV Equipment 499

11.25 UV Dose and Process Design Considerations 502

11.26 UV Reactor Validation 503

11.27 Emerging UV Issues 505

11.28 Boiling Water 505

Disinfection of Waterworks Facilities 506

11.29 Disinfection of Water Mains and Tanks 506

11.30 Control of Aftergrowth (Regrowths) in Distribution Mains 507

11.31 Disinfestation of Distribution Mains, Wells and Boreholes 507

References 508

xvi Contents

CHAPTER 12 Chemical Storage, Dosing and Control 51312.1 Chemicals Used in Water Treatment 513

12.2 Chemical Dosing Equipment 514

12.3 Chemical Dosing 522

Coagulants and Coagulant Aids 523

12.4 Coagulants 523

12.5 Coagulant Aids and Polyelectrolytes 527

pH Adjustment and Water Conditioning Chemicals 527

12.6 pH Adjustment 527

12.7 Sulphuric Acid 528

12.8 Hydrochloric Acid 528

12.9 Carbon Dioxide 529

12.10 HydratedLime 529

12.11 Sodium Hydroxide 531

12.12 Sodium Carbonate 531

Chlorine-Based Chemicals 531

12.13 Chlorine 531

12.14 Sodium Hypochlorite 535

12.15 Sodium Hypochlorite Production by Electrolysis 536

12.16 Calcium Hypochlorite 536

12.17 Chlorine Dioxide 537

Dechlorination Chemicals 537

12.18 Sulphur Dioxide 537

12.19 Other Dechlorinating Chemicals 538

Chloramination Chemicals 538

12.20 Ammonia 538

Oxidation Chemicals 539

12.21 Potassium Permanganate 539

12.22 Hydrogen Peroxide 539

Organics Removal 540

12.23 Powdered Activated Carbon (PAC) 540

Plumbosolvency Control 541

12.24 Phosphate Dosing 541

Caries Control 542

12.25 Fluoridation 542

Control Techniques 542

12.26 Chemical Dose Control 542

12.27 Flow Proportional Control 543

12.28 Feedback Control 543

12.29 Cascade Control 544

Contents xvi

12.30 Feed Forward Control 544

12.31 PID Control 545

Sampling and On-Line Analysis 545

12.32 Sampling 545

12.33 Water Quality Monitors 546

12.34 pH Monitors 548

12.35 Chlorine Analysers 549

12.36 Turbidity Monitors 550

References 551

CHAPTER 13 Energy Use, Sustainability and Waste Treatment 553

Part I Energy and Sustainability 553

13.1 Energy Use 553

13.2 Energy Efficiency 554

13.3 Water Conservation and Demand Management 558

13.4 Recovery of Energy and Chemicals 558

13.5 Carbon Accounting and Embedded Carbon 559

13.6 Sustainability and the Future 561

Part II Waterworks Waste and Sludge Disposal 562

13.7 Types of Waste 562

13.8 Types and Quantities of Sludge 564

13.9 Filter, Ion Exchange and Radionuclide Waste Disposal 567

13.10 Sludge Thickening and Disposal 570

13.11 Sludge Dewatering 572

13.12 Beneficial Uses of Sludge 577

References 579

CHAPTER 14 Hydraulics 581

14.1 The Energy Equation of Fluid Flow 581

14.2 Boundary Layers 583

14.3 Pipe Flow 584

14.4 Headlosses in Pipes (1) — The Colebrook—White Formula 586

14.5 Headlosses in Pipes (2) - Empirical Formulae 590

14.6 Local Headlosses at Fittings 592

14.7 Open-Channel Flow 594

14.8 Critical Depth of Flow 596

14.9 Froude Numbers 599

14.10 Headlosses in Channels 600

14.11 Hydraulic Jump 602

14.12 Non-Uniform, Gradually Varied Flow 603

xviii Contents

14.13 Weirs, Flumes and Gates 606

14.14 Measurement Weirs 610

14.15 Measurement Flumes 614

14.16 Venturi and Orifice Flow Meters 616

14.17 Other Flow Meters 618

14.18 Computational Fluid Dynamics (CFD) 618

References 619

CHAPTER 15 System Design and Analysis 621


15.2 System Layouts 622

15.3 Pipeline and System Planning 625

15.4 Distribution System Characteristics 628

15.5 Designing Trunk Mains 630

15.6 Designing Distribution Pipework 631

15.7 Hydraulic Design of Pipelines 633

15.8 System Curves 634

15.9 Longitudinal Profile 637

15.10 Air in Pipes 640

15.11 Transient Pressures: Water Hammer and Surge 642

15.12 Cavitation 646

15.13 Sizing a Pumping Main 647

15.14 Design of a Gravity Main 649

15.15 Pipeline Design Techniques 650

15.16 Water Quality Modelling 655

15.17 Updating of Network Models 656

15.18 Software Developments 656

References 657

CHAPTER 16 Distribution Practice 659

16.1 Condition and Performance of Network Assets 659

16.2 Service Levels 662

16.3 Distribution Network Management 664

16.4 Firefighting Requirements 668

16.5 Service Pipes 668

16.6 Waterworks Byelaws 675

16.7 Distribution System Maintenance 676

16.8 The Importance of Controlling Water Losses 677

16.9 Active Leakage Control 679

16.10 District Metering 680

Contents xix

16.11 Pressure Management 682

16.12 Waste Metering and Step-Testing 682

16.13 Locating and Repairing Leaks 683

16.14 Mains Rehabilitation 686

16.15 Pipe Lining Methods 689

16.16 Pipe Replacement 690

16.17 Improvement of Distribution Systems in Disrepair 691

Reference Standards 692

References 692

CHAPTER 17 Pipeline Design and Construction 693


17.2 Pipe Development 693

17.3 Materials and Potable Water 694

17.4 Abbreviations and Definitions 694

Pipeline Alignment and Material Selection 695

17.5 Alignment 695

17.6 Changes in Direction 695

17.7 Selection of Pipe Material 696

Pipeline Structural Design 697

17.8 Behaviour of Buried Pipes 697

17.9 Longitudinal Stresses in Buried Pipes 698

17.10 Buried Flexible Pipes 699

17.11 Above Ground Pipelines and Piping 701

17.12 Buried Pipework in Plants 702

Iron Pipes 703

17.13 Cast or 'Grey' Iron Pipes 703

17.14 Ductile Iron Pipes 703

17.15 External Coatings and Internal Linings 705

17.16 Joints for Iron Pipes 705

Steel Pipes 707

17.17 Steel Pipe Manufacture and Materials 707

17.18 Steel Pipe Wall Thickness 708

17.19 Factory-Made Bends and Other Steel Fittings 709

17.20 External and Internal Protection of Steel Pipe 710

17.21 Mortar and Concrete Linings 712

17.22 Joints for Steel Pipes 713

17.23 Lining and Coating Continuity at Field Joints 715

17.24 Cathodic Protection (CP) 715

Contents

Plastic Pipes 716

17.25 Polyethylene (PE) Pipes 716

17.26 Polyvinyl Chloride (PVC) Pipes 719

17.27 Glass Reinforced Plastics (GRP) Pipes 720

Concrete and Fibre Cement Pipes 723

17.28 Prestressed Concrete Pressure Pipes 723

17.29 Reinforced Concrete Cylinder Pipes 726

17.30 Reinforced Concrete Pressure Pipes 727

17.31 Fibre and Asbestos Cement (AC) Pipes 727

17.32 Polymer Concrete Pipes 728

Resistance to Internal Forces 728

17.33 Forces Due to Pressure and Velocity 728

17.34 Pipe Restraint and Thrust Blocks 729

Pipeline and Pipe System Construction 731

17.35 Choice of Pipes 731

17.36 Pipe Laying and Installation 731

17.37 Changes in Direction (Bends) in the Field 735

17.38 Testing of Pipelines 735

17.39 Making Connections 737

17.40 Underwater Pipelines 738


References 742

CHAPTER 18 Valves and Meters 743

Part I Valves 743

18.1 Valve Development 743

18.2 Valve Functions 743

18.3 Isolation 744

18.4 Regulation 744

18.5 Control 744

18.6 Valve Selection and Specification 747

18.7 Gate Valves 749

18.8 Butterfly Valves 750

18.9 Globe Valves 751

18.10 Screwdown Valves 752

18.11 Ball Valves 753

18.12 Plug Valves 754

18.13 Diaphragm Valves 754

18.14 Pinch Valves 755

18.15 Needle Valves 755

Contents xxi

18.16 Sleeve Valves 755

18.17 Hollow-Jet Discharge Valves 756

18.18 Non-Return (or Check) Valves 756

18.19 Flap Valves 757

18.20 Cavitation at Valves 758

18.21 Valve Operating Equipment 759

18.22 Valve Closure Speed 760

18.23 Washouts 760

18.24 Air Valves 761

18.25 Valve Chambers 765

Part II Measurement of Flow and Consumption 766

18.26 Purposes of Flow Measurement 766

18.27 Types of Flow Meter 766

18.28 Volumetric Flow Meters 768

18.29 Permanent Flow Meter Installations 769

18.30 Temporary Flow Measurement Devices 770

18.31 Supply (Revenue) Meters 771

18.32 The Accuracy of Water Meters 773

18.33 Future Trends in Metering 774

References 775

CHAPTER 19 Pumping, Electrical Plant, Control and Instrumentation 777

Part I Pumps 777

19.1 Pumping Plant 777

19.2 Centrifugal Pumps 777

19.3 Types of Centrifugal Pump 778

19.4 Characteristics of Centrifugal Pumps 782

19.5 Axial Flow and Mixed Flow Pumps 785

19.6 Reciprocating Pumps 786

19.7 Selection of Pumps for Water Supply 787

19.8 Pump Body and Impeller Selection 789

19.9 Standby Pumping Plant 789

19.10 Boosting 789

19.11 Increasing Pumping Station Output 791

19.12 Station Arrangement and Plant Layout 792

19.13 Pump Suction Design 794

19.14 Thermodynamic Pump Performance Monitoring 795

19.15 Cavitation Damage 796

19.16 Corrosion Protection 796

19.17 Transient Pressures: Water Hammer and Surge 797

xxii Contents

19.18 Efficiencies and Fuel Consumptions 797

19.19 Pump Drives 798

Part II Electrical Plant 799

19.20 Electric Motors for Pump Drives 799

19.21 The Induction Motor 801

19.22 Induction Motor Starting Methods 803

19.23 Induction Motor Protection 805

19.24 Speed Control of Induction Motors 806

19.25 Harmonic Filters 808

19.26 Effect of Electricity Tariffs 808

19.27 Electrical Power Supplies 809

19.28 Standby and Site Power Generation 811

19.29 Transformers 812

19.30 HV and LV Switchboards 812

19.31 Motor Control Centres 813

19.32 Electrical Cabling 814

19.33 Heating and Ventilation 815

Part III Control and Instrumentation (C&I) 815


19.35 Control 816

19.36 Automation 817

19.37 Control System Definition 817

19.38 Instrumentation 818

19.39 Systems 821

19.40 Communications 823

19.41 Hardware 826

19.42 Ancillary Equipment 827

19.43 Automation and Operation and Maintenance 827

References 827

CHAPTER 20 Treated Water Storage 829

20.1 Functions of Treated Water Storage 829

20.2 Storage Capacity Required 830

20.3 Ground or Elevated Storage 832

20.4 Statutory Consents and Requirements 832

20.5 Water Quality Considerations 833

20.6 Sampling and Water Testing 834

20.7 Instrumentation 834

20.8 Overflow and Drain Down Design 835

20.9 Ventilation 836

Contents xxiii

20.10 Loadings on Water Storage Reservoirs and Tanks 836

20.11 Water Retaining Concrete Design 836

20.12 Prestressed Concrete Circular Tank Design 838

20.13 Welded Steel Plate Design 838

Service Reservoirs 839

20.14 Reservoir Shape and Depth 839

20.15 Covering and Protecting Reservoirs 840

20.16 Service Reservoir Structures 841

20.17 Rectangular Jointed Concrete Reservoirs 842

20.18 Monolithic Concrete Reservoirs 845

20.19 Circular Reinforced Concrete Reservoirs 845

20.20 Cast In-Situ Prestressed Concrete Reservoirs 848

20.21 Precast Concrete Panel Reservoirs 849

20.22 Steel Plate Reservoirs 850

20.23 Panel or Sectional Tanks 851

20.24 Drainage and Waterproofing Concrete Service Reservoirs 852

20.25 Access to Service Reservoirs 853

20.26 Service Reservoir Pipework 853

20.27 Valve Houses for Service Reservoirs 856

20.28 Baffles in Service Reservoirs 856

Water Towers 857

20.29 Use of Water Towers 857

20.30 Concrete Water Towers 857

20.31 Welded Steel Water Towers 859

20.32 Segmental Plate Tanks 859

20.33 Pipework and Access for Water Towers 860

Testing Service Reservoirs and Tanks 860

20.34 Testing Procedure 860

20.35 Searching for Leaks 861

20.36 Cleaning and Disinfection 862

20.37 Inspection and Repair of Service Reservoirs 862


References 863

Conversion Factors 865

Index 867

Twort's water supply - GBV · 4.1 Groundwater, Aquifers andTheirManagement 117 4.2 Yield...

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