1

City of Dallas City of Dallas –– Water Utilities Department Water Utilities Department Advanced Leak DetectionAdvanced Leak Detection

Presented to Transportation and Environment Committee Presented to Transportation and Environment Committee January 12, 2009January 12, 2009

2

History of ProgramHistory of Program

Dallas Water Utilities implemented Leak Detection Program in FY0Dallas Water Utilities implemented Leak Detection Program in FY044--05054 staff members and equipment 4 staff members and equipment Program had expectations to survey system every 10 yearsProgram had expectations to survey system every 10 years

City Council approved $50K enhancements within FY06City Council approved $50K enhancements within FY06--07 budget07 budgetAdding new equipment to programAdding new equipment to programExpanding survey coverageExpanding survey coverage

City Council approved $652K enhancements within FY08City Council approved $652K enhancements within FY08--09 budget 09 budget Adding 6 staff members and equipment to program, which will incrAdding 6 staff members and equipment to program, which will increase ease staff to 14 staff to 14 Reducing frequency of pipeline survey from 5 to 2.5 yearsReducing frequency of pipeline survey from 5 to 2.5 years

3

Program FocusProgram Focus

Though we canThough we can’’t predict pipeline failures, todayt predict pipeline failures, today’’s technology helpss technology helpswater purveyorwater purveyor’’s to better identify and locate known and unknowns to better identify and locate known and unknownleaks within water system. leaks within water system.

Reduced Water loss Reduced Water loss –– conserves water and lessens impact to conserves water and lessens impact to environmentenvironmentFinancial Improvement Financial Improvement –– reduces chemical and electricity costs reduces chemical and electricity costs associated with treatment and delivery associated with treatment and delivery Safeguarding public health and property Safeguarding public health and property –– reduces likelihood of reduces likelihood of property damageproperty damageImproved public relations Improved public relations –– provides visual assurance that provides visual assurance that system is being maintainedsystem is being maintainedReduced disruption to customers Reduced disruption to customers –– enables repairs to occur on a enables repairs to occur on a planned basis rather than developing in to complete failure, planned basis rather than developing in to complete failure, reducing unexpected traffic and service interruptionsreducing unexpected traffic and service interruptions

4

FY 04-05

479 Miles

FY 05-06

511 Miles

FY 06–07

1001 Miles

FY 07–08

1217 Miles

Annual AchievementsAnnual Achievements

FY 08–09 Oct - Dec

277 Miles

5

Leak Detection Program FocusLeak Detection Program Focus

4100 Miles of Small diameter pipelines4100 Miles of Small diameter pipelinesComprises 85% of potable water system Comprises 85% of potable water system 22””--1212’’ diameter diameter

700 Miles of Large diameter pipeline700 Miles of Large diameter pipelineComprises 15% of potable water system Comprises 15% of potable water system Pipelines greater than 12Pipelines greater than 12””

6

Acoustic Leak DetectionAcoustic Leak Detection

Small Diameter PipelinesSmall Diameter Pipelines

Noise SurveyNoise Survey

7

Methodology Methodology

Noise SurveyNoise SurveyField survey utilizing high frequency contact Field survey utilizing high frequency contact microphone on water services and fire hydrants microphone on water services and fire hydrants aboveground. aboveground.

Acoustic CorrelationAcoustic CorrelationPermalog MK3 Leak Noise Loggers are attached Permalog MK3 Leak Noise Loggers are attached to pipes and fittings by field survey teamsto pipes and fittings by field survey teamsAccuCorr 3000 Correlators used to pinpoint the AccuCorr 3000 Correlators used to pinpoint the leak by correlation teams leak by correlation teams

8

Acoustic CorrelationAcoustic Correlation

X

Loggers captures leak as it radiates through pipelineLoggers captures leak as it radiates through pipelineCorrelatorCorrelator pinpoints the leakpinpoints the leak

CorrelatorCorrelator

LoggerLogger LoggerLogger

9

Small Diameter ResultsSmall Diameter Results

Since inception of program,Since inception of program, DWU DWU has:has:

Surveyed 3,485 miles of pipelineSurveyed 3,485 miles of pipelineIdentified 791 unknown leaks Identified 791 unknown leaks Average of 0.23 leaks per mileAverage of 0.23 leaks per mileCorrelated and marked an additional 800 known Correlated and marked an additional 800 known leaks for repair, effectively eliminating return trips leaks for repair, effectively eliminating return trips and time spent on location.and time spent on location.

10

Large Diameter ProgramLarge Diameter Program

Although correlators have proven to be effective in detecting Although correlators have proven to be effective in detecting leaks on majority of pipe types and sizes, they have leaks on majority of pipe types and sizes, they have limitations. The leak signal dissipates more rapidly within limitations. The leak signal dissipates more rapidly within larger diameter pipelines. larger diameter pipelines.

In 2004, with the approval of City Council, Dallas Water In 2004, with the approval of City Council, Dallas Water Utilities established a price agreement with Pressure Pipe Utilities established a price agreement with Pressure Pipe Inspection Company for surveys of pipelines >12Inspection Company for surveys of pipelines >12”” diameter diameter using Sahara technology.using Sahara technology.

Sahara is a patented acoustic system that has been widely used throughout the world. Sahara was invented by Water Resource Center (WRC) within the UK.

11

Leak LocationLeak Location

SaharaSahara®®: System: SystemReal Time Data ProcessingReal Time Data Processing

FrequencyFrequency

Energy/Amplitude of SoundEnergy/Amplitude of Sound

Tracking toolTracking tool

Sensor Head attached to cable within a live pipelineSensor Head attached to cable within a live pipeline

12

Sahara: Tethered, InSahara: Tethered, In--line Operationline Operation

Drogue

Sensor Head

Umbilical Cable

Flow Direction

13

Synopsis of Large Diameter ProgramSynopsis of Large Diameter Program

CBD and Fair ParkCBD and Fair Park24 different areas 24 different areas

Customer Cities Supply Pipelines Customer Cities Supply Pipelines 12 different areas12 different areas

Raw Water Transmission PipelinesRaw Water Transmission Pipelines3 different areas3 different areas

Trinity River Floodway and West DallasTrinity River Floodway and West Dallas13 different areas13 different areas

East DallasEast Dallas21 different areas21 different areas

North DallasNorth Dallas8 different areas8 different areas

South DallasSouth Dallas18 different areas18 different areas

14

Large Diameter Results Large Diameter Results

Surveyed 40.68 miles of large diameter Surveyed 40.68 miles of large diameter transmission mains (12transmission mains (12”” –– 8484””) with SAHARA ) with SAHARA Identified 60 leaks Identified 60 leaks Average of 1.5 leaks per mile Average of 1.5 leaks per mile

15

Total AchievementsTotal Achievements

0

100

200

300

400

500

600

700

FY04-05 FY05-06 FY06-07 FY07-08 FY08-09

HUND

REDS

Known Leaks PinpointedUnknown Leaks Detected

FY08-09 is YTD

16

Total AchievementsTotal Achievements

* Studies have shown (American Waterworks Association) that wate* Studies have shown (American Waterworks Association) that water leaks r leaks may exist for up to two years prior to complete failure.may exist for up to two years prior to complete failure.

Monthly Average Water Savings

0

50

100

150

200

250

300

350

FY04-05 FY05-06 FY06-07 FY07-08 FY08-09

Mill

ions

Gal

lons Large Diameter

Small Diameter

FY08-09 is YTD

17

Total AchievementsTotal Achievements

* Leak detection program has effectively prevented 18% or 1651 p* Leak detection program has effectively prevented 18% or 1651 pipelines ipelines from reaching total failure. from reaching total failure.

0

500

1000

1500

2000

2500

3000

3500

FY04-05 FY05-06 FY06-07 FY07-08 FY08-09

HUN

DRE

DS

Unknown Leaks DetectedKnown Leaks CorrelatedReported Failures

FY08-09 is YTD

18

Questions?Questions?