Page 12 - Water Loss Control

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14 Controlling Apparent Losses from Systematic
Data Handling Errors in Customer Billing Systems . . . . . . . . . . . . . 225
14.1 Compiling Billed Consumption in Customer
Billing Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
14.2 Using the Customer Billing System to Extract Customer
Water Consumption Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
14.3 Adjusting for Lag Time in Customer Meter Reading Data . . . 230
14.4 Determining the Volume of Apparent Loss Due to Systematic
Data Handling Error in Customer Billing Systems . . . . . . . . . 233
14.5 Billing Policy and Procedure Shortcomings . . . . . . . . . . . . . . . 240
14.6 Quantifying Systematic Data Handling Errors in the
Water Audit and Addressing These Losses . . . . . . . . . . . . . . . . 245
15 Controlling Apparent Losses—Unauthorized Consumption . . . . . . 247
15.1 Unauthorized Consumption Occurs in Many Ways . . . . . . . . 247
15.2 Quantifying the Volume of Unauthorized Consumption
in the Water Audit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
15.3 Controlling Unauthorized Consumption . . . . . . . . . . . . . . . . . 249
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
16 Controlling Real Losses in the Field—
Proactive Leak Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
16.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259
16.2 Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261
16.3 Leakage Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
16.4 Leak Detection Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
16.5 Leak Detection Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275
16.6 Zoning and District Metered Areas . . . . . . . . . . . . . . . . . . . . . . 281
16.7 Testing for Reservoir Leakage . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
16.8 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
17 Controlling Real Losses—Speed and Quality of Leak Repair . . . . . 295
17.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
17.2 Leak Runtime Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
17.3 Quality of Leak Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
17.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299
18 Controlling Real Losses—Pressure Management . . . . . . . . . . . . . . . . 301
18.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301
18.2 Why Undertake Pressure Management Schemes? . . . . . . . . . . 302
18.3 Various Types of Pressure Management . . . . . . . . . . . . . . . . . . 307
18.4 Leakage Control—Pressure Leakage Theories . . . . . . . . . . . . . 312
18.5 Overflow Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314

18.6 Fundamental Monitoring Points . . . . . . . . . . . . . . . . . . . . . . . . . 315
18.7 Flow Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
18.8 Pressure Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316