Singapore s Experience of Water Loss Reduction. Lai Kah Cheong Chief Engineer 7 Sep 17

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1 Singapore s Experience of Water Loss Reduction Lai Kah Cheong Chief Engineer 7 Sep 17

2 Biodata of Singapore ~34km Singapore, 718 km2 ~53km Population, 5.6m Annual rainfall 2,400 mm Average water demand 1.95 million m 3 /d (430 mgd) 55% Non-Domestic 45% Domestic

3 The Water Loop 2 From sourcing, collection, purification and supply of drinking water, to treatment of used water and turning it into NEWater, drainage of storm water

4 Sustainable Water Management Four National Taps

5 Our Water Supply System From Waterworks to Customers Taps 4 Highly integrated network dispatching treated water from various sources Ring main system to provide alternate feed 5,500 km Portable Water (PW) pipelines 605 km NEWater (NW) pipelines 39 km Industrial Water (IW) pipelines

6 UFW % 5 Singapore s Unaccounted-for-Water (UFW) Unaccounted-For Water Effect of Replacement Programme: Lower UFW Replacement programme of unlined CI mains and GI connections Replacement programme of leak prone mains and AC / CI mains

7 Our UFW Management Framework 6 Network Management 1. Use good quality / corrosion-resistant material 2. Strict supervision & control on workmanship 3. Regular servicing and replacement Accurate Metering % metering 2. Use of compound meters to capture both low flows and high flows Low UFW Active Leakage Control 1. Annual leak detection programme 2. Use of smart sensors in the network 3. Pursuing trials actively with a view to adopt (e.g. permanent monitoring of large water mains, Satellite imaging leak detection) Strict Legislation Strict Enforcement on water theft Penalties: $50,000 fine or; 3 years jail term or; both fine & jail term

8 Key Challenges Ahead 7 Difficulties in Leak surveillance and in Setting up of DMA zones Growing Asset Base & Ageing Infrastructure Maintaining expanding and ageing infrastructure for low UFW and efficient supply Complex Network and Open Zones Challenges Urban Congestion Rising Water Demand Reduce water loss for efficient and sustainable water supply Growing population and economy Complex Design and construction More costly method of laying pipes (e.g. pipe jacking or tunneling)

9 Network Life Cycle Management 8 Design and Construction Predictive Maintenance Continuous monitoring

10 Design and Construction 9 Localised Corrosion Monitoring with CMAS Use of Coupled Multi-electrode Array Sensor (CMAS) for measurement of localised corrosion Some locations with CMAS results Quick and easy to obtain results (5mins) vs traditional soil tests (6 weeks) Helps to determine if increased protection necessary at the pipe laying stage Based on 5 mm thickness Asset lifespan : 70 years

11 Principle of CMAS Probes for Corrosion Monitoring

12 Design and Construction 11 Surrounding soil Check Corrosiveness CMAS/Soil Testing Recognize the conditions e.g. high water table Pipe Move towards pipes with PU Coating Additional Protection Use of bedding - quarry dust in normal circumstances Cathodic protection to minimise corrosion Additional wrapping for exposed pipes and pipes in common services tunnel QC Record baseline condition for new pipelines Conduct CCTV inspection for internal defects Inspect for external defects Eg. Check coating is intact using Direct Current Voltage Gradient (DCVG) analysis

13 Continuous Monitoring of the Network 12 Smart Water Grid 320 sensors deployed island-wide to monitor in real-time the pressure, flow and quality of water in our network ENHANCE OPERATIONS Early detection of leaks, pipe burst and water quality incidents Improve response time Minimise impact to customers New Regulations Strict new regulations for inspection and monitoring of new construction along the pipe corridor Moving Forward 120 sensors on 100km of critical transmission mains for leak detection Install more sensors to improve the coverage of PW network, and to also cover NW and IW networks in the next 3 years.

14 13 Continuous Monitoring of the Network AMR Automated Meter Reading AMR and boundary flow meters - identify the area of potential leaks at the macro level through Virtual DMA Virtual DMA retaining supply reliability while achieving leak detection

15 Predictive Maintenance Framework of Pipeline Condition Assessment 14 1) Desktop asset management, data analytics, 2) Field, Non-Invasive Survey Methods Analyse asset characteristics based on age/ material/ location/ failure history Pipe wall thickness measurement, coating defect survey, leak detection 3) Field, Invasive Survey Methods RFT pipeline condition assessment, in-line CCTV 4) Field, Intrusive, Destructive Test Coupon sampling and lab testing; section cut outs and lab testing Replace Rehabilitate Defer Monitor Repair

16 Predictive Maintenance Risk-Based Study to Prioritise Pipelines for Renewal Ongoing pilot study by Arcadis for ~700km of cast iron pipelines. 15 Considers both likelihood of failure and consequence of failure to prioritise pipelines for renewal. Extend similar analysis to facilitate prioritisation of renewal for the rest of the network from 2018 onwards. Preliminary Results for 700km of CI pipelines

17 Predictive Maintenance Develop Capabilities Pipeline Condition Assessment Non-invasive Methods P-Cat Uses pressure transients to determine the thickness of various sections of pipeline. epulse Uses acoustics sensors to induce sound waves to measure average wall thickness over intervals. Wilson Taylor Echologics DCVG & CIPS Direct Current Voltage Gradient (DCVG) & Close Interval Potential Survey (CIPS) to detect protective coating defects Will embark on pilot condition assessment of 7.5km of aged large diameter Cast Iron water mains in City area in We plan to implement regular condition assessment on our watermains in the long-term.

18 Predictive Maintenance Develop Capabilities Pipeline Condition Assessment Invasive Methods PICA (SeaSnake Remote Field Technology) Electro-magnetic method; Detect defects through the pipe length and around the circumference. Pipe Diver Smart Ball In-line Leak detection SAHARA Functions include: In-line Leak detection CCTV Submersible CCTV or ROV Visual inspection of internal condition of pipe. MTA Pipe Inspector Cable-Less Video inspection with Integrated Leak Detection

19 Predictive Maintenance Develop Capabilities Trenchless Pipe Renewal Methods 18 Increasing underground space constraints, especially for replacement of large diameter trunk mains. Pipejacking and Tunnelling carry out water main rehabilitation trials. Rehab Method using PE-Lined pipes Congestion of underground services Non-conventional renewal method: Pipe-bursting Learning from Hong Kong on their watermain rehabilitation experience: Carry out open-cut replacement of pipelines where possible; pipe rehabilitation is mainly carried out for straight length of pipe. Not preferred for distribution mains with many off-takes.

20 Thank you