Leak Detection Methods

Report
Leak Detection Methods
A Workshop for Communities
Implementing Water Loss
Management
Prepared for Columbia Basin Trust
by IKEN Services Ltd.
May 2013
• 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.
Quick Review from January 2013
• IWA Water Balance Components
• Night Flow Analysis
• Real Loss vs. Background Leakage
IWA Standard Water Balance
Authorized
Billed
Authorized
Consumption
Consumption
Unbilled
Authorized
Consumption
System
Apparent
Losses
Input
Volume
Billed Metered Consumption
Revenue
Water
Billed Unmetered Consumption
Unbilled Metered Consumption
Unbilled Unmetered Consumption
Unauthorized Consumption
Non
Customer Meter Inaccuracies
Revenue
Water
Water
Leakage on Transmission &
Distribution Mains
Losses
Real
Losses
Leakage and Overflows at
Reservoirs
Leakage on Service Connections
up to metering point
7
7
Putting the Pieces Together
UARL calculation based on
•mains length,
•number of services,
•customer meter location
•average pressure
Pressure
Pressure
Management
Management
Infrastructure Leakage
Index ILI
= CARL/UARL
(ICF is zone ILI)
Unavoidable
Annual Real
Losses UARL
Active
Speed
and
Leakage
Quality
of
Control
Repairs
Current Annual Real Losses
CARL
Pipeline and
PipeAssets
Materials
Management:
Management:
selection,
Selection,
installation,
Installation,
maintenance,
Maintenance,
renewal,
Renewal,
replacement
Replacement
Speed
and
Active
quality
Leakage
of repairs
Control
8
Active Leakage Control Measures
• 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.
Tackling Unreported Break Awareness
FLOW RATE
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!
BURST DURATION
A
L
R
TIME
FLOW RATE
Tackling Unreported Break Location
BURST DURATION
A
L
R
TIME
FLOW RATE
Tackling Unreported Break Repair
BURST DURATION
A
L
R
TIME
Active Leakage Control Measures
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Flowrate
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Sonic Leak Surveys
The 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
Bursts with high flow rates don’t produce
the largest volume of Real Losses! Run time is a key factor.
75
1.1 Days
m3 / day
m3 / day
m3 / day
reported mains
burst
82.5 m3
reported service
connection burst
400 m3
16 Days
25
A
L R
182.5 Days
25
A
unreported service
connection burst
> 4500 m3
L
R
time period (5 minute intervals)
5:00:00
4:50:00
4:40:00
4:30:00
4:20:00
4:10:00
4:00:00
3:50:00
3:40:00
3:30:00
3:20:00
3:10:00
3:00:00
2:50:00
2:40:00
2:30:00
S2
2:20:00
2:10:00
2:00:00
1:50:00
1:40:00
1:30:00
1:20:00
1:10:00
1:00:00
0:50:00
0:40:00
0:30:00
0:20:00
0:10:00
0:00:00
flow (litres/sec)
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
8
7
6
S1
5
4
S3
S4
3
2
1
0
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.
Townshipof KingTemporaryDMAExercise
NightlyPressureProfiles, Schomberg
October 28- November 1, 1999
31.8
31.7
Legend
31.6
October 30, 1999
31.5
31.4
Pressure(m)
November 1, 1999
31.3
31.2
October 29, 1999
31.1
31.0
October 31, 1999
October 28, 1999
30.9
30.8
1:00
1:30
2:00
2:30
Time(a.m.)
3:00
3:30
4:00
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.
Group Work- Learning
Objectives
• Familiarization with types of leak
detection equipment
• Locating leakage in real time
• Distinguishing between types of sound
• Logistics for conducting leak sweeps
Field Exercise- Agenda

Three Leak Areas

Progress through each station


Each operator uses equipment to
pinpoint noise
Move to next station
Field Exercises- Location
C:\Users\Mike\Desktop\AATraining\CBT
2012\Administrative\leakdetection\Creston Leak Detection Zones (May 2013).pdf
Group Work- Learning
Objectives
• Break into three groups:
– Jamie- using the correlater area 1
– Mike- leak locating area 2
– Meredith/Elise- leak locating area 3
Field Exercises- Location
C:\Users\Mike\Desktop\AATraining\CBT
2012\Administrative\leakdetection\Creston Leak Detection Zones (May 2013).pdf
Field Exercise- Agenda

Reform groups

Return to each station

Confirm leakage location and type


Review successes/challenges with
different types of equipment
Move to next station
Developing a Water Loss Plan
• 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?
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/watersmart
[email protected]
Meredith Hamstead, Coordinator
Columbia Basin Water Smart

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