-1- 游叡研幫工程司 Water Leakage Improvement Ray-Yen, YU Assistant Engineer Taipei Water Department 2013 Seoul Study Workshop

-2- Outlines Introduction The Way to Improve Leakage Successful case sharing Achievements

-3- *Supply Area: 434 km 2 *Customers: 3.8 million *Supply Capacity: 2.7 million CMD *Networks: Mains=3,600 km Services=2,700 km Major Figures of TWD

-4- Only one main water source Leakage rate(28.4%) was too high in 2002

-5- Dead level 120 low level 130 mid level 138 water level (m) Feitsui Reservoir Drought of 2002 Worse nightmare came true: Intermittent water supply for 2 months high level 164

-6- Lack of replacement resulted in heavy leakage in Taipei Leakage Control was never a consideration in the past. Put all money into system expansion of Water Supply.

-7- Pipeline Replacement with DMA Zone Dividing Leakage Metering Pipeline Replacement Long-term Monitoring Using DMA as an auditing tool : To evaluate the quality of pipeline replacement and to fix the problem The Way to Improve Leakage

-8- DMA Flow meter 1000~4000 Households Pipeline replacement strategy ： Low revenue rate (High leakage) DMA first

day consumption 15-day intake volume Revenue rate = ( consumption) Intake volume  M To evaluate the replacement job by Revenue Rate Leakage Estimation Techniques Meter reading method ：

-10- Determining Leaking rate MNF Method Probabilistic MNF Determining Leaking Places Leak in MNF Actual leak (MNF overstate leakage) A : minor leaking B: no leaking C : major leaking Step Metering

-11- M M “Direct” metering the leaking volume of pipes Direct Metering Curb stop Valve Mobile Flow meter

-12- Pipeline Replacement is definitely not an easy job Replace pipes Meter leak volumes Get approval Monitor DMA Acquaint with residents

-13- Achievements

-14- After Revenue rate being increased in DMAs 165 DMAs’ pipeline being replaced Before

others DMAs YangMing South North West East DMAs being set

% 93% 54% 92%95% 56%59% 94% year Before replacement After replacement Before & After Pipeline replacement revenue rate DMAs being finished Revenue rate increasing dramatically 93% 50%

-17- Long-term projectMid-term IWA suggested replacing rate （ 1.5 ％ /year ） Pipeline replacement length Replacement rate surpassing 1.5% in 10 consecutive years

-18- Leakage rate being reduced 9.34% Long-term project Mid-term

NRW=1000 kCMD 2012 NRW=670 kCMD Reducing 47 kCMD /each year NRW= System input - Revenue volume days (normalize to CMD) NRW dropped Long-term project

-20- Advising Users to Move Water Meters to the Front of Houses Successful Case Sharing

-21- About 200 meters in the houses or behind houses. Our goal is to persuade all users to move the meters to the front of houses and cut off old pipes.

Before Construction: 1.convene a meeting 2.Post notices 3.Persuade users one by one

Link the tap directly 接上水龍頭 水塔 Attention: If users have indirect equipments, then you should tell users to change equipments in advance.

-24- leaking obviously The sound of leaking is so noisy that you can even hear it near gutter. Successfully Persuade users to move meters to the front of houses. 中正路 42 巷全部用戶表位從防火 巷遷移屋前 (totally 30 meters) Leaking seriously

-25- 中正路 62 號後方防火巷 Leakage Improvement Cut off old 75mm PVC Pipe When we cut off old pipes leaking seriously, Revenue rate is up to ％ that achieves our goal. When we cut off old pipes leaking seriously, Revenue rate is up to ％ that achieves our goal. After we communicate with users actively and visit them at night several times,finally all users agree to move the meter. We save NRW for 386CMD/per day 。

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-27- After the construction, we make sure that the old pipe have no water. 轉開止水栓, 確認舊管已斷除 ( 無水 )

-28- After the construction, we use hammer to break old pipe and make sure there is no water. So we are sure it is successful. 鐵鎚敲斷防火巷舊管（確認舊管已無水）

(before) Leaking water keeps flowing (after) no leaking anymore The films about leakage improvement.

-30- After all the efforts, we successful move all the meters to the front of the houses. And we cut off all the old and leaking pipes. It is like a mission impossible. The users want to express their appreciation to us. So the neighborhood manager awards us testimonial as a gratitude. 福林里里長致贈感謝狀 Awards

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