north american water loss conference 2017 · leak detection results 939 leaks detected inline 722...

North American Water Loss Conference

2017

Trunk Main Leak Detection – Ten Years of Inline

Acoustic Data

By Carl Sharkey

NRW – No Single Solution

0% 20% 30% 40% 50% 60% 70%10%%NRW

Pump

Management

Advanced

Pressure

Management

Leak

Detection

Condition

Assessment

Pipe Repair

Asset

Management

Systematic

Pipe

Replacement

Accurate

Meters

Pressure

Management

Advanced

Leak

Detection

Large Diameter Acoustics

Leaks on small diameter pipes are easy to detect

Frequent fittings

Strong sound propagation along pipe wall and water column

Larger diameter pipes are more difficult to hear

Infrequent fittings

Buried deep below ground

Poor record keeping/maps

Poor sound propagation as signal attenuates very quickly

Net

wo

rk C

om

ple

xity External

Internal Tethered

Internal Free Swimming

Pipe Diameter

Inline Acoustic Tools

Free Swimming Tethered

Miles of Data

4513

39097987 Leaks

95 leaks per 100 miles

Leaks Per 100 Miles Inspected by Type

Steel53

BWP21

CI211AC

81 PCCP34

DI68

PVC58

Source: Free Swimming database

7161

39

73

4943

2821

26

0

10

20

30

40

50

60

70

80

90

18 24 30 36 42 48 54 60 66 72

Leak

s p

er

10

0 m

iles

Pipe Diameter (in)

Leaks Per 100 Miles Inspected by Size

Note: Bubble size is proportional to

amount of pipe inspected at that diameter

Source: Free Swimming database

Types of Leaks Found in Cast Iron

Feature31%

Joint 39%

Barrel22%

Unknown 8%

Cast Iron

Source: Free Swimming database

Case Study 1: Jalur Cahaya Sdn

Bhd (JC) – Malaysia

• Free swimming and tethered

technology are part of the

‘technology toolbox’

• NRW is approximately 35%

• Holistic NRW program to reduce

losses (60% real, 40% apparent)

through a range of methods

Start of 2 Year Program

DescriptionTotal No.

of DMA

Pipe

Length

(miles)

Total

Customers

SIV

(mgd)

NRW

(mgd)

NRW

(%)

Inside DMA 1,182 9,316 1,262,616 470 128 27%

Outside

DMA6,934 680,293 762 297 39%

Completed Tasks

11

• Replaced 20,000 service pipes

• Implemented and updated GIS

• Updated all NRW software

• Repaired and replaced pipes

• Free Swimming on 1,250 mi

• Tethered on 50 mi

• External on 1717.5 mi

• Established 120 DMAs

• Established 160 WBAs

• Repaired 1300 DMA and WBAs

• Installed 65 advanced PRVs

• Installed 900 tank sensors

• Repaired 150,000 leaks

Leak Detection Results

939Leaks Detected

Inline 722

External 217

55

64

13

Free Swimming

Tethered External

Leaks per 100 miles

Inspected

Case Study 2: Dallas Water Utilities

Drivers for Program1. Maintain reliable water delivery (large,

critical mains)

2. High per capita water use (2004)

3. Reduce water main leaks (leaks become

breaks)

4. Meet goals for Texas’ 5-year Water

Conservation Plan

5. Public perception/water restrictions

Small Diameter Mains

14

Leak Survey Localize with Correlators

Pinpoint

• 14 dedicated staff (5 crews)• Entire system every 2.5 years• Focused on 12” diameter and lower

Small Diameter Leak Results

-

10

20

30

40

50

60

FY07 FY08 FY09 FY10 FY11 FY12 FY13 FY14 FY15

Leaks per 100 miles of Inspection

Large Diameter Mains

Free Swimming72 miles

Tethered 168 miles

208Leaks Found

and Repaired

Tethered Leak Detection Results

130 Leaks per 100 miles

Mostly Cast and

Ductile Iron Pipe

Carl Sharkey• 530-379-5633

• Carl.Sharkey@puretechltd.com