A Workshop for Communities Implementing Water Loss Management Prepared for Columbia Basin Trust by...
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Transcript of A Workshop for Communities Implementing Water Loss Management Prepared for Columbia Basin Trust by...
A Workshop for Communities Implementing Water Loss
Management
Prepared for Columbia Basin Trust by IKEN Services Ltd.
May 2013
Leak Detection Methods
• Introductions & Learning Objectives
• Review of Prior Work on Water Loss
• Leak Detection Methods & Equipment
• Break
• Field Work: Leak Detection Tools/Methods/Equipment
• Lunch
• Field Work: Leak Detection Tools/Methods/Equipment
• Break
• How Leak Detection Fits into a Water Loss Management Plan
By the end of this workshop participants will:
• Understand the role that leak detection plays in an overall Water Loss Management Program;
• Become familiar with the tools and equipment used in leak detection;
• Be able to identify types of distribution system leakage by various acoustic methods;
• Determine the feasibility and economy of common leak detection methods for their utility.
Community status reports
• On a sheet of flip chart paper, list the work done to date on water loss management in your utility.
• IWA Water Balance Components
• Night Flow Analysis
• Real Loss vs. Background Leakage
Quick Review from January 2013
7
System
Input
Volume
Authorized
Consumption
Revenue
Water
Non
Revenue
Water
Billed
Authorized
Consumption
Unbilled
Authorized
Consumption
ApparentLosses
RealLosses
Water
Losses
Billed Metered Consumption
Unbilled Unmetered Consumption
Unauthorized Consumption
Customer Meter Inaccuracies
Leakage on Transmission &Distribution Mains
Billed Unmetered Consumption
Unbilled Metered Consumption
Leakage on Service Connections up to metering point
Leakage and Overflows at Reservoirs
IWA Standard Water Balance
7
Putting the Pieces Putting the Pieces TogetherTogether
UARL calculation based on •mains length,•number of services,•customer meter location•average pressure
Pressure M anagem ent
Pressure
Management
Infrastructure LeakageIndex ILI
= CARL/UARL(ICF is zone ILI)
Active LeakageControl
Speed and Quality of Repairs
Speed and quality
of repairs
Active Leakage Control
Pipe M aterials M anagem ent:
selection,installation,
m aintenance,renew al,
replacem ent
Pipeline and Assets
Management: Selection,
Installation, Maintenance,
Renewal, Replacement
Unavoidable Annual Real
Losses UARL
Current Annual Real Losses CARL
8
• Active leakage is defined as an active effort to locate and repair unreported leaks
• Sonic Survey• Correlation Surveys• Noise Logging Surveys• Night Flow Sector Analysis• Temporary or Permanent
District Metered Area• Step Testing• Transmission Main Surveys
Active Leakage Control Measures
• We're going to look at acoustic methods of leak detection
• to support work done already in Night Flow Analysis within District Metered Areas.
Active Leakage Control Measures
Tackling Unreported Break Awareness
Awareness: length of time a leak runs before utility personnel are aware of it - you can't repair
what you don't know is out there!
A L R
BURST DURATION
FL
OW
RA
TE
TIME
Tackling Unreported Break Location
A L R
BURST DURATION
FL
OW
RA
TE
TIME
Tackling Unreported Break Repair
A L R
BURST DURATION
FL
OW
RA
TE
TIME
Active Leakage Control Measures
Recorded Profile vs. Estimated Legitimate Demand
12:00 AM 1:00 AM 2:00 AM 3:00 AM 4:00 AM 5:00 AM
Time
Flo
wra
te Estimated Leakage
Recorded Profile
Estimated Legitimate Demand
Sonic Leak SurveysThe basic method for finding any leak is sounding. This method involves listening to each main’s fitting and service connection stop taps in a zone, DMA or suspected area, to determine if there is a noise that could potentially be a leak.
Sonic Leak Surveys…• Should be considered as a preventive
maintenance program; conducted routinely regardless of whether more advanced leakage methods are used.
• Not as effective on non-metallic pipes.
• Can be labour intensive
• Difficult to determine achieved savings or effectiveness without other monitoring in place.
…Sonic Leak Surveys• Incorporate listening methods when doing other
maintenance:– Hydrants– Valves– Service repairs– Main repairs
Noise Logging Surveys• Analysis of acoustic logger data
• A good leak noise will produce a steady concentrated sound.
• Typically a high peak with a narrow spread
• General wide spreads with no definite peaks are normal when no leaks are present
Noise Logging Surveys
Sonic Ground Microphone Surveys• Hard on the technician – walking and listening!• Everything sounds the same after a while.• Very effective over short distances.• Better used as leak location confirmation tool.
Correlation Surveys• More effective then sonic surveys but also much more time consuming and expensive.
• Correlation equipment in constant development.• Best used as a leak pinpointing tool.
Correlation Pinpointing• Correlation is only as good as information provided!• Proper training needed to interpret results.• Always confirm with ground microphone, if possible.
Correlators in Hard Situations• Unknown mixed pipe situation.
• I can hear it … but it won’t correlate!
• Background Noise!
Repair Time• The “Repair” component deals with how quickly the leak is isolated or a repair crew is dispatched and the repair completed.
• The “Quality” aspect covers the actual repair itself and is geared towards ensuring the following key components:
• Safety• Water Quality• Proper Training• Documentation
m3
/ day
75
reported mains burst
82.5 m3
1.1 Days
Lm3
/ day
unreported serviceconnection burst
> 4500 m3
25182.5 Days
RA
m3
/ day
16 Days
reported service connection burst
400 m3
25
RLA
Bursts with high flow rates don’t produce the largest volume of Real Losses! Run time is a key factor.
Step Testing
(Isolating (valving) sections of the DMA)
Step testing lets you sector off parts of your DMAs to further prioritize leak localization efforts.
Step Test between 1am & 3am
0
1
2
3
4
5
6
7
8
0:00
:00
0:10
:00
0:20
:00
0:30
:00
0:40
:00
0:50
:00
1:00
:00
1:10
:00
1:20
:00
1:30
:00
1:40
:00
1:50
:00
2:00
:00
2:10
:00
2:20
:00
2:30
:00
2:40
:00
2:50
:00
3:00
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3:10
:00
3:20
:00
3:30
:00
3:40
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3:50
:00
4:00
:00
4:10
:00
4:20
:00
4:30
:00
4:40
:00
4:50
:00
5:00
:00
time period (5 minute intervals)
flow
(litr
es/s
ec)
Reservoir Drop Test• By isolating a reservoir to a known area and determining the rate of
fall in the reservoir, minimum night flow can be established.
Township of King Temporary DMA ExerciseNightly Pressure Profiles, Schomberg
October 28 - November 1, 1999
30.8
30.9
31.0
31.1
31.2
31.3
31.4
31.5
31.6
31.7
31.8
1:00 1:30 2:00 2:30 3:00 3:30 4:00
Time (a.m.)
Pre
ssu
re (
m)
October 28, 1999
October 29, 1999
October 30, 1999
October 31, 1999
November 1, 1999
Legend
Active Leakage Control +Pressure Management
• Flow rates from unreported breaks are commonly estimated and added.
• But, as leaks are fixed, system pressure rises…• …background leakage increases…• …new breaks may be generated.
• Thus actual reduction in night flow is less then estimated.
• But…if pressure management is possible, pressure can be reduced as breaks are repaired.
• And full benefit obtained from active leakage control intervention.
• Familiarization with types of leak detection equipment
• Locating leakage in real time
• Distinguishing between types of sound
• Logistics for conducting leak sweeps
Group Work- Learning Objectives
Three Leak Areas
Progress through each station
Each operator uses equipment to pinpoint noise
Move to next station
Field Exercise- Agenda
Field Exercises- Location
C:\Users\Mike\Desktop\AATraining\CBT 2012\Administrative\leakdetection\Creston - Leak Detection Zones (May 2013).pdf
• Break into three groups:
– Jamie- using the correlater area 1
– Mike- leak locating area 2
– Meredith/Elise- leak locating area 3
Group Work- Learning Objectives
Field Exercises- Location
C:\Users\Mike\Desktop\AATraining\CBT 2012\Administrative\leakdetection\Creston - Leak Detection Zones (May 2013).pdf
Reform groups
Return to each station
Confirm leakage location and type
Review successes/challenges with different types of equipment
Move to next station
Field Exercise- Agenda
• With other members at your table, review your community's leak detection program
• Analyze needs in order to begin leak detection as presented
Developing a Water Loss Plan
• Present to the larger group results of your analysis and include:
• Budget
• Resources
Developing a Water Loss Plan
• What strategies are available to your community in order to meet Water Loss Targets?
• Advanced training?
• Pooled resources?
• Contract services?
Developing a Water Loss Plan
What's Next for Your Community?
Summary
Question & Answer
Evaluation & Wrap Up
• District Metered Areas Guidance Notes, 2007, J. Morrison, Water Loss Task Force
• Managing Leakage By DMA- A Practical Approach, J. Morrison, IWA Task Force 2004
• A Manager's Non Revenue Water Handbook, Farley & Wyeth, 2008
• AWWA Water Loss Committee
• NZ Water Loss Guidelines, Richard Taylor 2010
www.cbt.org/[email protected]
Meredith Hamstead, CoordinatorColumbia Basin Water Smart