Waterworks Office Seoul Metropolitan Government Water for All http://arisu.seoul.go.kr Kevin Young June Choi All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. http://arisu.seoul.go.kr Contents 1 Waterworks System in Korea 2 Waterworks Systems in Seoul 3 Issues and Challenges 4 Water Operators Partnership All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government 1 Waterworks Office Seoul Metropolitan Government Waterworks works!! All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks works!! Only waterworks can do it! 5.4 mil. tons/day (Total capacity of Seoul) 3.5 mil. tons produced and distributed daily 433,750 trucks required distributed without waterworks systems (i.e., pipe lines) http://arisu.seoul.go.kr Waterworks in the US 1907: 1st filtration facility 1914: disinfection by chlorination Waterworks works!! • 1900: 30 out of 100,000 died of typhoid fever • 1928: 5 out of 100,000 died of water-born disease All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government 2 Waterworks in History Ancient time Groundwater or surface water Roman Empire, BC 312 ~ BC 305 578 km of aqueduct • Fountains, public bathhouse, other public buildings http://arisu.seoul.go.kr Europe 6th century • Population growth in Paris and London • Waterworks systems to use the Thames and the Seine 1830: Cholera outbreak (from contaminated drinking water) 1852: Law of waterworks announced (London) All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government http://arisu.seoul.go.kr Waterworks in Korea Unified Shilla dynasty (7th~10th century) Clay pipe network for water use Pusan, 1895 First treated water supply Seoul, September 1, 1908 First modern style waterworks system Dduksum WTP Pyungyang, Pusan, and Daegu 1947 after WWII 40,000 tons/day 66 lpcd 1954 after Korean War Rebuilding waterworks system with foreign funds Economic development plan (1962~1992) The percentage of population served in 2004: 90.1% All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government 3 Waterworks Office Seoul Metropolitan Government Supply All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Service in Korea • US 85%, Japan 96% Nation wide Production Supplied Qty Supplied Qty per Percentage capacity [1,000 [1,000 capita per day served [%] tons/day] tons/day] [lcpd] 49,053 44,187 90.1% 23,156 Special and Wide area cities 23,068 22,793 98.8% 14,930 8,153 358 Cities 16,618 16,166 97.3% 6,146 6,071 376 Eup 4,076 3,364 82.5% 1,347 1,255 373 Myun 5,291 1,864 35.2% 16,145 365 733 666 357 100% 90% Percent served [%] Population served 49 million people (90.1%) Total Population Population served [thousand] [thousand] 80% 70% 60% 50% Unbalanced service ratio High service ratio in cities: Enhanced social infra-structure for urbanization 84 cities (97.3%; Special city and large area city 98.9%) and 212 Eups (82.5%) 719 Myuns (35.2%) Need to extend waterworks service in rural and island areas 40% 30% 20% 10% 0% http://arisu.seoul.go.kr Nation wide All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Special and Wide area cities Cities Eup Myun Waterworks Office Seoul Metropolitan Government 4 Current Trends in Supply 420 90% 410 Supply per capita per day [lcpd] 91% Served Ratio [%] 89% 88% 87% 86% 85% 84% 83% 82% 400 390 380 370 360 350 340 330 81% 1997 1998 1999 2000 2001 2002 2003 1997 2004 1998 1999 2000 2001 2002 2003 2004 60 Population [million] http://arisu.seoul.go.kr 50 40 30 20 Total Population [million] 10 Population served [million] 0 1997 1998 1999 2000 2001 2002 2003 2004 Waterworks Office Seoul Metropolitan Government All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Supply by Area 100% 83.2% 91.2% 97.0% 78.3% 61.5% 76.1% http://arisu.seoul.go.kr 98.4% All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. 91.5% 80.8% 99.4% 81.4% 97.8% 99.1% 64.7% 100% Waterworks Office Seoul Metropolitan Government 5 WTP Capacities by Area Seoul Pusan Daegu Incheon Kwangjoo Daejeon Woolsan 5.4 2.7 1.8 2.6 0.8 1.1 0.6 Kyungki 2.8 30.5% 15.3% 10.2% 14.6% 4.7% 5.9% 3.1% 15.7% Kangwon Choongbook Choongnam Chunbook Chunnam Kyungbook Kyungnam Jeju 0.8 0.4 0.2 0.3 0.8 1.3 1.2 0.5 4.3% 2.0% 1.4% 1.7% 4.3% 7.4% 7.0% 2.6% 30.5% 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 4.3% 15.7% 14.6% 2.0% 1.4% 84.3% 7.4% 5.9% 60.8% http://arisu.seoul.go.kr Big Cities Metropolis Capacity [M ton/day] Capa. % Population [Mil.] Pop. % Big sities Metropolis area 14.9 10.8 64.5% 46.5% 23.1 23.5 47.0% 48.0% 3.1% 1.7% 10.2% 7.0% 4.7% 15.3% 4.3% 2.6% All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government Waterworks Office Seoul Metropolitan Government Distribution System All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. 6 Length of Pipe Line Length of pipe line for drinking water distribution: Total length: 127,027 km Intake~WTP: 1,439 km (1.1%) WTP~Distribution point: 5,973 km (4.7%) Reservoir~Pumping station: 59,406 km (46.8%) Pumping station~Tap: 60,209 km (47.4%) 70,000 59,406 http://arisu.seoul.go.kr Total length [km] 60,000 60,209 50,000 40,000 30,000 20,000 10,000 5,973 1,439 - Waterworks Office Seoul Metropolitan Government All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Old Pipe Line Length of old pipe line Over 21 years: 17,953 km (14.1%) 16~20 years: 23,918 km (18.8%) 11~15 years: 30,988 km (24.4%) 6~10 years: 27,255 km (21.5%) Less than 5 years: 26,912 km (21.2%) 35,000 24.4% Total length [km] http://arisu.seoul.go.kr 30,000 21.5% 20,000 21.2% 18.8% 25,000 14.1% 15,000 > 21 years 16~20 years 11~15 years 6~10 years <5 years 10,000 5,000 > 21 years 16~20 years 11~15 years 6~10 years Length [km] Ratio [%] 17,953 14.1% 23,918 18.8% 30,988 24.4% 27,255 21.5% 26,912 21.2% <5 years All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government 7 Waterworks Office Seoul Metropolitan Government Source Water and Treatment All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Source Water and Treatment Source Water Surface water Underflow water Lake water Groundwater http://arisu.seoul.go.kr Lake water 23% Q'ty [1,000 m^3] Percent [%] 13,133 65.3% 1,889 9.4% 22.5% 4,527 554 2.8% Groundwater 3% Underflow water 9% All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Surface water 65% Waterworks Office Seoul Metropolitan Government 8 Source Water and Treatment Treatment Technology Q'ty [1,000 ton/day] 4,913 16,478 636 1,129 Advanced treatment Rapid filtration Slow filtration Simple treatment http://arisu.seoul.go.kr Simple treatment 5% Slow filtration 3% Percent [%] 21.2% 71.2% 2.7% 4.9% Advanced treatment 21% Rapid filtration 71% All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government Waterworks Office Seoul Metropolitan Government Production All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. 9 Production 1997 6,039 4,344 71.9% 1,695 1,145 19.0% Produced [Mil. Ton] Supplied [Mil. Ton] Effective Ratio [%] UFW [Mil. Ton] Leaked [Mil. Ton] Leakage [%] 1998 5,840 4,129 70.7% 1,711 1,056 18.1% 1999 5,798 4,258 73.4% 1,540 934 16.1% 2000 5,812 4,342 74.7% 1,470 859 14.8% 2001 5,791 4,367 75.4% 1,424 804 13.9% 2002 5,696 4,395 77.2% 1,301 700 12.3% 2003 5,723 4,489 78.4% 1,234 781 13.6% 2004 5,909 4,633 78.4% 1,276 839 14.2% 20% 80% 18% 16% 14% 76% Leakage Effective Ratio 78% 74% 72% 12% 10% 8% 6% 70% 4% 68% 2% 0% 66% 1998 1999 2000 2001 2002 1,800 2003 2004 1997 1998 1999 2000 2001 2002 2003 2004 1,600 1,400 UFW [Mil. Ton] http://arisu.seoul.go.kr 1997 1,200 1,000 800 600 400 200 1997 1998 1999 2000 All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any 2001 form or by any means without the prior written permission of Young-june Choi, when used commercially. 2002 2003 2004 Waterworks Office Seoul Metropolitan Government Waterworks Office Seoul Metropolitan Government Price & Personnel All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. 10 Price Supplied price [U$/ton] Production cost [U$/ton] Realization rate [%] 1997 1998 1999 2000 2001 2002 2003 2004 0.33 0.37 0.42 0.47 0.52 0.54 0.56 0.58 0.48 0.53 0.56 0.62 0.60 0.63 0.63 0.67 69.4% 69.8% 74.1% 75.2% 85.9% 86.5% 89.3% 86.2% Supplied price [U$/ton] Production cost [U$/ton] 0.8 100% 0.7 90% 80% Rate [U$/ton] http://arisu.seoul.go.kr 0.6 70% 0.5 60% 0.4 50% 0.3 40% 30% 0.2 20% 0.1 Realization rate [%] Realization rate [%] 10% 0.0 0% 1997 1998 1999 2000 2001 2002 2003 2004 All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government Price by Area Local self-governing bodies Young-wol, Kangwon-Do: 1.12 U$/m3 • Mountainous area Kwa-chun, Kyungki-Do: 0.29 U$/m3 http://arisu.seoul.go.kr • Suburb area of Seoul • Government offices, Green city Cities and Provinces Daegu Large-area city: 0.46 U$/m3 Woolsan Large-area city: 0.81 U$/m3 Seoul Metropolis: 0.54 U$/m3 Difference in price Supply by large area drinking water distribution system Source water development Distance between source water and consumers Size of WTP Cost to produce drinking water Administrative and financial conditions of water authority All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government 11 Personnel As of December 2004 Total 15,365 officers http://arisu.seoul.go.kr • • • • Administrative officer: 1,887 (12.3%) Technical officer: 3,440 (22.4%) Operator: 6,107 (39.7%) Part-time staff: 3,931 (25.6%) 20,000 10,000 18,000 9,000 16,000 8,000 14,000 7,000 12,000 6,000 10,000 5,000 8,000 4,000 6,000 3,000 4,000 2,000 2,000 Administrative officer Technical officer Operator Part-time staff 1,000 1997 1998 1999 2000 2001 2002 2003 2004 1997 All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. 1998 1999 2000 2001 2002 2003 2004 Waterworks Office Seoul Metropolitan Government Waterworks Office Seoul Metropolitan Government Cooperation All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. 12 Cooperation with Regulator and Operator Regular communication with the regulator Ministry of Environments • Regulations related with drinking water quality Ministry of Construction and Transportation http://arisu.seoul.go.kr • Regulations related with construction of water utilities and facilities Having no regular meeting but discussing on the issues through many channels All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government Waterworks Office Seoul Metropolitan Government Utility Specific Issues All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. 13 Arisu: Drinking Water for Seoulites ‘Ari’ means ‘Big’ or ‘Large’. ‘Su’ stands for ‘Water’ or ‘River’. http://arisu.seoul.go.kr Arisu was the name of the Han River in ancient time, flowing through the very middle of Seoul. The Waterworks Office of Seoul Metropolitan Government have been providing the citizens with the bottled tap water with the brand name of “Arisu” since April 2004. Waterworks Office Seoul Metropolitan Government All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Unaccounted-for Water (UFW) (Unit: Thousand tons) Total supply Effective supply UFW 1997 1,785,452 1,170,863 614,589 1998 1,673,817 1,073,865 599,952 1999 1,579,119 1,077,055 502,064 2000 1,523,246 1,097,402 425,844 2001 1,470,516 1,106,127 364,389 2002 1,379,340 1,092,993 286,347 2003 1,334,913 1,104,368 230,545 2004 1,310,538 1,117,554 192,984 2,000,000 1,800,000 (Unit: Thousand tons) Total supply UFW 1,600,000 1,400,000 1,200,000 1,000,000 800,000 http://arisu.seoul.go.kr 600,000 400,000 200,000 1997 1998 1999 2000 2001 All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. 2002 2003 2004 Waterworks Office Seoul Metropolitan Government 14 http://arisu.seoul.go.kr Future Development Plan Water Quality Improvement Water quality monitoring – 145 items recommended by WHO Source water with the best quality Application of advanced water treatment technologies AOP, BAC, GAC, Ozone, Membrane filtration Stabilization of Production/Supply System Increasing reservoirs to distribute treated water Supply system without suspension in any case Improving Administrative Conditions Effective supply system (metered water ratio: 90%) Effective administrative system (EIS and dataware house) Customer Satisfaction One-stop solution for customer complaint Arisu quality control system Improving PR for Arisu All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government http://arisu.seoul.go.kr Summary of Standards Treated Water Quality Standards Turbidity: <0.3 NTU N-NO3: <10 mg/L Fe: <0.3 mg/L Hardness: <300 mg/L as CaCO3 THM: <0.1 μg/L pH: 5.8~8.5 Source Water with the Best Quality All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government 15 Overview of Water Demand Management Upgrading WTP Facilities To replace and repair old facilities • Inefficient, high cost WTP → Application of Advanced Treatment Technologies • Continuous maintenance of facilities • Youngdeunpo WTP (600,000 m3/day) – Old facility of 300,000 m3/day → Ozone and GAC • Kangbook WTP (1,700,000 m3/day) http://arisu.seoul.go.kr – Extending capacity of 700,000 m3/day Expanding Service Reservoirs Pressure stabilization/equalization Control the quantity for distribution All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government Overview of Water Demand Management Supply System without Suspension Maintenance of WTP’s (U$ 24.4 Mil.) http://arisu.seoul.go.kr • From 5.4 Mil. m3/day in 2005 to 5.1 Mil. m3/day in 2008 • Optimization of WTP’s facilities Improving Revenue Water Ratio From 85.3% in 2004 to 90.5% in 2007 Application of IT on Waterworks Administration Seoul Water Now system Real time water quality monitoring system Will be integrated with the other databases of pressure and quantity of delivered drinking water Integrating GIS, MIS, and Water quality and quantity monitoring system All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government 16 Current Issues Tap water 1.7% Spring water 7.7% Bottled water 8.6% Ground water 0.7% Boiled tap water 42.3% Purified tap water 38.9% C hemical addition 0.2% http://arisu.seoul.go.kr Taste 50.1% 5.1% Materials other than water 6.0% Mass media 6.2% 12.2% Rust 26.3% Smell 43.9% No special reason 0% All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. 10% 20% 30% 40% 50% Waterworks Office Seoul Metropolitan Government Key Recommendations http://arisu.seoul.go.kr Education of kids, parents and teachers Open administration and management Share information on water quality and supply with the citizens or the customers Emphasize that “Water for All” Increasing governance with citizens All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government 17 Waterworks Office Seoul Metropolitan Government Water Operators Partnership All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. http://arisu.seoul.go.kr International Solidarity Exchanging technical information, data, knowledge, and experience The first stage by Seoul Metropolitan Government America: US, Canada, Mexico Asia: China, Japan, Mongolia, Myanmar, Pakistan, Vietnam, and so on Europe: Netherlands, Denmark and so on. UN’s support Role as an organizer and mediator for the solidarity Keep the connection not in uni- or bi-directional relationship but in systematic networks All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government 18 Domestic Partnership Council of Waterworks Research Institutes of Korea Leaded by WRI of Seoul Metropolitan Government Have regular meeting every six months Reporting progresses in technical aspects • Improving existing technologies • Applying new technologies http://arisu.seoul.go.kr Discuss hot issues related with water industry • Regulations on standards, tariff, application of new technologies • Organizing nation-wide conferences No private sector allowed to participate Current issues • Uni-directional flow of information and experience • Different financial structure and condition All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government http://arisu.seoul.go.kr More To Go Council of Waterworks Research Institutes of Korea KOWACO (public corporation for water service) technical partnership with Vietnam, Peru, Iraq, and Pakistan through KOICA in some countries, they had difficulties to get what they wanted through the partnership Contacting Washington DC and Philadelphia for technical level partnership Attending Capacity building workshop All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government 19 Waterworks Office Seoul Metropolitan Government All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Office Seoul Metropolitan Government Hyper-linked Information All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. 20 Waterworks Service in Korea http://arisu.seoul.go.kr Total Population Population served [thousand] [thousand] Production Supplied Qty Supplied Qty per Percentage capacity [1,000 [1,000 capita per day served [%] tons/day] tons/day] [lcpd] Nation wide 49,053 44,187 90.1% 23,156 16,145 365 Special and Wide area cities 23,068 22,793 98.8% 14,930 8,153 358 Cities 376 16,618 16,166 97.3% 6,146 6,071 Eup 4,076 3,364 82.5% 1,347 1,255 373 Myun 5,291 1,864 35.2% 733 666 357 Special city: Seoul Wide-area cities: Self-governing large cities with direct relationship with the central government. 6 cities (Pusan, Daegu, Incheon, Gwangju, Daejeon, Woolsan) Cities: Administrative unit. Population over 50,000. Eup: Population over 20,000 Myun: Population less than 20,000 Waterworks Office Seoul Metropolitan Government All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Waterworks Service in Korea 100% 90% Percent served [%] 80% 70% 60% 50% 40% 30% http://arisu.seoul.go.kr 20% 10% 0% Nation wide Special and Wide area cities Cities All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Eup Myun Waterworks Office Seoul Metropolitan Government 21 Revenue Water Ratio 80% Effective Ratio 78% 76% 74% 72% 70% http://arisu.seoul.go.kr 68% 66% 1997 1998 1999 2000 2001 2002 2003 2004 Waterworks Office Seoul Metropolitan Government All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. Percent Leakage 20% 18% 16% Leakage 14% 12% 10% 8% 6% http://arisu.seoul.go.kr 4% 2% 0% 1997 1998 1999 2000 All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. 2001 2002 2003 2004 Waterworks Office Seoul Metropolitan Government 22 UFW 1,800 1,600 http://arisu.seoul.go.kr UFW [Mil. Ton] 1,400 1,200 1,000 800 600 400 200 1997 1998 1999 2000 All rights reserved. No part of this file may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means without the prior written permission of Young-june Choi, when used commercially. 2001 2002 2003 2004 Waterworks Office Seoul Metropolitan Government 23
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