Performance-based Leakage Reduction and Management Services SAWACO Zone 1 Training and Transfer of Technology Outline Classroom Training Modules Field Training Modules 2 2 Outline Classroom Training Modules Module 1 DMA Design Module 2 DMA Construction and Commissioning Module 3 Active Leakage Control Module 4 Pressure Management 3 3 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 4 4 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 5 5 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 6 6 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 7 7 Classroom Training Module 1 DMA Design Planning, Design and Engineering Planning and Prioritization 8 Field Survey Preliminary Design Hydraulic Simulation Draft Report Final report 8 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 9 • Manila Water prioritization was initially based on the following: • Pipe material • Pipe age • Number of leak occurrences 9 Classroom Training Module 1 DMA Design Planning, Design and Engineering • Data gathered during site investigation: Field Survey 10 • • • • • Location and status of existing valves, fire hydrants and blow-offs. Big consumption customers Pressure Road classification Traffic 10 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 11 • • • • District 1 – 24 DMAs District 3 – 29 DMAs District 5 – 28 DMAs District 10 – 38 DMAs 11 Classroom Training Module 1 DMA Design Planning, Design and Engineering Hydraulic Modelling 12 • 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 12 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 13 • DMA Description • DMA Information • Quantity of work • Applicable Standards • DMA Design • Drawings • Work Schedule • Work Methodology • Site Regulation and Safety 13 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 14 • Combination of DMAs are done in order to pass the requirements of the hydraulic simulation and other design criteria 14 Classroom Training Module 2 DMA Construction and Commissioning Permit Acquisition 15 Civil Works Commissioning Works 15 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 16 16 Classroom Training Module 2 DMA Construction and Commissioning Permit Acquisition 17 17 Classroom Training Module 2 DMA Construction and Commissioning • Line Meter Assemblies • Isolation Valves • Looping and Interconnection Activities Civil Works • Pipelaying Activities • Fire Hydrants 18 18 Classroom Training Module 2 DMA Construction and Commissioning Civil Works Line Meter Assembly 19 Electromagnetic Flow Meter Pressure Reducing Valve Strainer By Pass Connection Panel Box 19 Classroom Training Module 2 DMA Construction and Commissioning • Water Adequacy Test • Zero Pressure Test Commissioning Works 20 • Baseline Measurement • Baseline Report 20 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 21 21 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 22 22 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). 15 75mm 100mm 200mm 27 26 2 3 M 5 25 7 8 17 13 150mm 4 11 75mm 1 16 14 10 9 12 18 19 20 21 6 22 23 24 – 23 If water is adequate within & outside the DMA, let all Isolation Valves be remained closed as supply will now pass through the District Meter. 23 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 24 24 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. 25 25 Classroom Training Module 2 DMA Construction and Commissioning Water Adequacy Test -Unidentified night users (0.06lpm/wm) -Leaks (Physical Loss) 13 Supply 1 M 2 3 4 11 5 10 9 7 8 12 -Identified Night Users Supply= Allowable Night6 Flow + Physical + Identified Night Users Physical Losses= Supply- Allowable Night Flow -Identified Night Users 26 26 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 27 27 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. 28 Calculate baseline leakage 28 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 29 29 Classroom Training Module 2 DMA Construction and Commissioning Data Logging and Data Transfer 30 30 Classroom Training Module 3 Active Leakage Control Analysis and Control 31 Leak location/detection Leak repair Monitoring and Measurement 31 Classroom Training Module 3 Active Leakage Control Four Pillars of Physical Loss Management Water Losses due to Leakage 32 32 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 33 33 Classroom Training Module 3 Active Leakage Control Leak location /detection 34 • 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 34 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 35 35 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. 36 36 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. 37 37 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) 13 1 2 4 M M 11 5 3 10 12 9 8 7 6 38 • Close Step-Test Valves @ 15min interval • Open Step-Test Valves @ 15min interval (REVERSE OPERATION) 38 Classroom Training Module 3 Active Leakage Control Step Testing 100WSC 350 lpm 13 1 2 M M 150WSC 4 5 3 11 195 lpm 10 1145 lpm 795 lpm 195 lpm 12 600 lpm 9 8 7 500WSC 6 39 39 Classroom Training Module 3 Active Leakage Control Equipment Ground Microphone Leak Noise Loggers GPR Leak Noise Correlators 40 40 Classroom Training Module 3 Active Leakage Control Leaks commonly occur on: Service Connection Service pipe Tapping House meter assembly Mainline Main pipe Joints Valve 41 41 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 42 42 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 43 43 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 44 44 Classroom Training Module 4 Pressure Management Pressure Management and Modulation 45 45 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 46 46 Outline Field Training Modules 47 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 47 Xin Cám Ơn! 48 48