Zone_1_Training_and_Transfer_of_Technology_English_version
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Transcript Zone_1_Training_and_Transfer_of_Technology_English_version
Performance-based Leakage Reduction
and Management Services
SAWACO Zone 1
Training and Transfer of Technology
Outline
Classroom Training Modules
Field Training Modules
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Outline
Classroom Training Modules
Module 1 DMA Design
Module 2 DMA Construction and Commissioning
Module 3 Active Leakage Control
Module 4 Pressure Management
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Classroom Training Module 1
DMA Design
Definition of District Metering Area (DMA)
is a world-wide accepted tool to operate and manage a
network area wherein hydraulic boundary is defined by a
system of Isolation Valves (IV) an flow Meters
a discrete area of a water distribution network. It is usually
created by closing boundary valves so that it remains flexible
to changing demands. However, a DMA can also be created by
permanently disconnecting pipes to neighboring areas. Water
flowing into and out of the DMA is metered and flows are
periodically analyzed in order to monitor the level of leakage
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Classroom Training Module 1
DMA Design
Definition of District Metering Area (DMA)
has water service connections ranging from 500-3,000
can be categorized into the following types:
Single inlet DMAs
Multiple inlet DMAs
Cascading DMAs
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Classroom Training Module 1
DMA Design
General Guidelines in DMA Design
DMAs should not include trunk mains or storage tanks
Each DMA should preferably be supplied through a single,
metered supply point
DMA boundaries should be created by closing boundary valves
Variations in ground elevation should be minimal across the
DMA
The types of consumers and their respective water supply
requirements should be assessed
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Classroom Training Module 1
DMA Design
General Guidelines in DMA Design
Legal regulations governing minimum pressures, local
constraints due to topography and height of buildings as well
as fire fighting requirements have to be respected
Closing boundary valves to create DMAs will increase the
number of dead-end pipes
Pressure management plays a key role in leakage management
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Classroom Training Module 1
DMA Design
Planning, Design and Engineering
Planning
and
Prioritization
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Field Survey
Preliminary
Design
Hydraulic
Simulation
Draft Report
Final report
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Classroom Training Module 1
DMA Design
Planning, Design and Engineering
• Preliminary design by Manila Water design team in coordination with
MWH network modelling team
• Prioritization by highest leakage potential
Planning and
Prioritization
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• Manila Water prioritization was initially based on the following:
• Pipe material
• Pipe age
• Number of leak occurrences
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Classroom Training Module 1
DMA Design
Planning, Design and Engineering
• Data gathered during site investigation:
Field Survey
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•
•
•
•
•
Location and status of existing valves, fire hydrants and blow-offs.
Big consumption customers
Pressure
Road classification
Traffic
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Classroom Training Module 1
DMA Design
Planning, Design and Engineering
• Preliminary design of 119 DMAs in the Feasibility Study done in 2005
• One line meter per DMA with a range of 1000-2000 service connections
• DMAs per District
Preliminary
Design
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District 1 – 24 DMAs
District 3 – 29 DMAs
District 5 – 28 DMAs
District 10 – 38 DMAs
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Classroom Training Module 1
DMA Design
Planning, Design and Engineering
Hydraulic
Modelling
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• MWH conducted the hydraulic simulation based on the initial design
submitted by MWC
• The term hydraulic network model describes the use of a mathematical
representation of a real water supply system
• Hydraulic network models are used to simulate the behavior of existing or
planned systems under a wide range of conditions without disrupting
service to the customer
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Classroom Training Module 1
DMA Design
Planning, Design and Engineering
• The preliminary DMA design report is based on Decree 209/2004 (Quality
Managements of Construction Works) which contains the following:
Draft Report
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• DMA Description
• DMA Information
• Quantity of work
• Applicable Standards
• DMA Design
• Drawings
• Work Schedule
• Work Methodology
• Site Regulation and Safety
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Classroom Training Module 1
DMA Design
Planning, Design and Engineering
• Approval of the preliminary report is sought in order to produce the 10
copies of final report
Final Report
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• Combination of DMAs are done in order to pass the requirements of the
hydraulic simulation and other design criteria
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Classroom Training Module 2
DMA Construction and Commissioning
Permit
Acquisition
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Civil Works
Commissioning
Works
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Classroom Training Module 2
DMA Construction and Commissioning
• Preparation of Drawings with underground obstructions
• Process of Issuance of UTM Agreement
• Submission of DOT Agreement
Permit Acquisition • Submission of DOT Permit
• Issuance of Permit
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Classroom Training Module 2
DMA Construction and Commissioning
Permit Acquisition
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Classroom Training Module 2
DMA Construction and Commissioning
• Line Meter Assemblies
• Isolation Valves
• Looping and Interconnection Activities
Civil Works
• Pipelaying Activities
• Fire Hydrants
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Classroom Training Module 2
DMA Construction and Commissioning
Civil Works
Line Meter Assembly
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Electromagnetic Flow Meter
Pressure Reducing Valve
Strainer
By Pass Connection
Panel Box
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Classroom Training Module 2
DMA Construction and Commissioning
• Water Adequacy Test
• Zero Pressure Test
Commissioning
Works
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• Baseline Measurement
• Baseline Report
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Classroom Training Module 2
DMA Construction and Commissioning
Water Adequacy Test
Water Adequacy Test will be conducted to ensure sufficiency of water supply
within the isolated DMA despite of having only a single supply point
WAT starts with the measurement of pressure at benchmark points within and
outside of the DMA prior to and after closure of all isolation valves
It is important that during the conduct of Water Adequacy Tests (WAT), all
service connections covered by a particular DMA is identified, verified and
tagged
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Classroom Training Module 2
DMA Construction and Commissioning
Water Adequacy Test Steps
1.
Identify all boundary valves.
2.
Determine if the valves are operable, if not, replace the boundary valve.
3.
Monitor the pressure before and after isolation inside and outside the DMA
4.
Before closing any valve, install pressure gage in the hydrant inside the DMA
5.
Close the boundary valve one by one
6.
Continue closing all boundary valves
7.
Compare the pressure before and after the isolation
8.
If there is a big pressure drop, the DMA needs to be redesigned or introduce
and additional supply usually by opening the critical boundary valve
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Classroom Training Module 2
DMA Construction and Commissioning
Water Adequacy Test
–
–
Check Pressure w/in &
outside DMA
Close all Isolation Valves
Let water pass thru District Meter (inflow &outflow).
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75mm
100mm
200mm
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3
M
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150mm
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75mm
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If water is adequate within & outside the DMA, let all Isolation Valves be remained
closed as supply will now pass through the District Meter.
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Classroom Training Module 2
DMA Construction and Commissioning
Zero Pressure Test
ZPT is conducted following the Water Adequacy Test to ensure the
tightness of isolations
In principle, once all the isolation valves are closed including the
inflow/s, pressure inside the DMA should drop to zero until no water
comes out of the monitoring point/s
The test is normally done during off-peak hours (1AM to 4AM), when
demand is at its lowest and pressure is theoretically at its peak
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Classroom Training Module 2
DMA Construction and Commissioning
Zero Pressure Test Steps
1.
Inform the customers about the schedule of the water interruption.
2.
Identify critical point, usually the hydrant in the lowest elevation of the DMA.
3.
Closed all the supply points
4.
Open the hydrant to check if there will be no water (preferably the hydrant in the lowest elevation inside
the DMA).
5.
If there is still water after several minutes, check all the boundary valves if they are tightly closed.
6.
If all the boundary valves are fully closed and still there is water in the monitoring point, then there is
unknown inflow inside the DMA.
7.
Check where the pressure is the highest as the unknown inflow may be in that area.
8.
Check old maps for old lines.
9.
Use GPR, pipe locator and other equipment to find old lines.
10. Conduct step testing to localize the location of unknown lines.
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Classroom Training Module 2
DMA Construction and Commissioning
Water Adequacy Test
-Unidentified
night users
(0.06lpm/wm)
-Leaks
(Physical Loss)
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Supply
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-Identified Night
Users
Supply= Allowable Night6 Flow + Physical + Identified Night Users
Physical Losses= Supply- Allowable Night Flow -Identified Night Users
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Classroom Training Module 2
DMA Construction and Commissioning
Baseline Measurement
If Water Adequacy and Zero Pressure Test are successful, the next
step is to conduct the baseline measurement
Baseline Measurement is done to determine the baseline NRW of a
particular DMA
Baseline measurement is usually done on the period of 7 days to
capture one complete cycle of water consumption pattern in the DMA
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Classroom Training Module 2
DMA Construction and Commissioning
Baseline Measurement Steps
1.
Identify all the water service connection inside the DMA based on the design boundary.
2.
Identify and replace all defective water meters before baseline measurement to increase
the accuracy of data.
3.
Carry out the baseline measurement. Read all DMA meters (inflow and outflow) on the 1st
and 7th day, ideally at the same time. Compute Qi in m3/day.
4.
Read all customer meters on day 1 and 7 of the measurement. First and second reading
of a specific meter should be at approximately the same hour of the day.
5.
Calculate the total metered consumption of all customers in the DMA by utilizing the 90
day billing average from SAWACO or JSC and calculate the daily average QM (m3/d).
6.
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Calculate baseline leakage
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Classroom Training Module 2
DMA Construction and Commissioning
Baseline Measurement Formula
Lb = Qi – Qm
Where
Lb = Leakage during baseline in m3/day
Qi = DMA inflow in m3/day
Qm = metered consumption (billed volume) in m3/day
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Classroom Training Module 2
DMA Construction and Commissioning
Data Logging and Data Transfer
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Classroom Training Module 3
Active Leakage Control
Analysis and
Control
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Leak
location/detection
Leak repair
Monitoring and
Measurement
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Classroom Training Module 3
Active Leakage Control
Four Pillars of Physical Loss Management
Water
Losses due
to Leakage
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Classroom Training Module 3
Active Leakage Control
• A proactive strategy to reduce water loss through detection of
nonvisible leaks
• Involves the regular survey of the water network using one or
Analysis and
Control
more techniques in detecting leaks in water mains
• Performing night flow measurements on a regular basis to detect
new leaks as soon as possible
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Classroom Training Module 3
Active Leakage Control
Leak location
/detection
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• Leak Detection or localizing by means of a step test or acoustic
logging survey enables the leakage engineer to narrow down the
location of the leak or burst to an individual road or length of main
• Next activity for the leakage engineer is to precisely locate or
pinpoint the position of the leak and mark the point clearly on
the ground surface where the repair teams will have to excavate
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Classroom Training Module 3
Active Leakage Control
Step Testing
Step testing is the technique whereby a leak or leaks are detected by
making temporary successive valve closures to reduce the size of a
DMA
The valves are closed for a short duration whilst
simultaneously measurements of the rate of flow are being
made
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Classroom Training Module 3
Active Leakage Control
Step Testing Procedure
Survey and check the operability of all the existing valves inside the DMA.
Plan the sequence of step test segment carefully utilizing the information
gather from the valve survey.
Schedule the activity during minimum demand usually 12:00 – 4:00 am.
Inform the customers in advance regarding the Step test activity.
Start closing the valves from the segment farthest from the line meter. Record
valve details (location and no. of turns) and time of closure;
Read the transmitter (totalizer and instantaneous flow) after every valve
closure or set data logging every minute for more comprehensive data.
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Classroom Training Module 3
Active Leakage Control
Step Testing Procedure
Continue the step test until all segment are completed, the last segment being
the area supplied by the line meter. If possible, check if there is no water in
each segment.
Open the valves slowly in reverse order.
Do flushing activity to avoid dirty water complaint.
Analyze the step test data to determine the segment with the highest possible
leakage.
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Classroom Training Module 3
Active Leakage Control
Step Testing
If DM has no Data Logger, read mtr. @ 5 min. interval
This is done 15min before the 1st STV is closed up to the last STV is re-opened.
Upload Mtr (if Logger Ready)
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• Close Step-Test Valves @ 15min interval
• Open Step-Test Valves @ 15min interval (REVERSE
OPERATION)
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Classroom Training Module 3
Active Leakage Control
Step Testing
100WSC
350 lpm
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1
2
M
M
150WSC
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5
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195 lpm
10
1145 lpm
795 lpm
195 lpm
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600 lpm
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500WSC
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Classroom Training Module 3
Active Leakage Control
Equipment
Ground Microphone
Leak Noise Loggers
GPR
Leak Noise Correlators
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Classroom Training Module 3
Active Leakage Control
Leaks commonly occur on:
Service Connection
Service pipe
Tapping
House meter assembly
Mainline
Main pipe
Joints
Valve
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Classroom Training Module 4
Pressure Management
Definition of Pressure Management
the practice of managing system pressures to the optimum
levels of service ensuring sufficient and efficient supply to
legitimate uses and consumers, while reducing unnecessary
excess pressures, eliminating transients and faulty level
controls all of which cause the distribution system to leak
unnecessarily
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Classroom Training Module 4
Pressure Management
Zone 1 Experience
the overall aim is to ensure that the pressure during the day is
not significantly lower that the pressure at night. To keep the
pressure within optimal levels inside the DMA, PRVs previously
installed with the rest of the flow meter set assembly will be
operated
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Classroom Training Module 4
Pressure Management
Pressure Reducing Valve (PRV)
maintains the optimum pressure in the
network at all times, but automatically
compensates for the reduced flow
following the repair of the leaks whilst
maintaining
the
original
operating
pressures in the DMA
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Classroom Training Module 4
Pressure Management
Pressure Management and Modulation
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Classroom Training Module 4
Pressure Management
Pressure Management and Modulation
Modulation Location
Local point pressure modulation
Critical point pressure modulation
Modulation Type
Fixed outlet pressure modulation
Time-based pressure modulation
Flow-based pressure modulation
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Outline
Field Training Modules
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Water Adequacy Test
Zero Pressure Test
Step-Testing
Use of leak noise correlator
Use of leak pen in leak detection
Use of ground microphone for leak detection
Line meter and PRV operation
PMAC Familiarization/ Data Center
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Xin Cám Ơn!
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