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