Ensuring quantity and quality of raw water for water supply Methodology of Japan Japan Water Agency KUMAGAI Kazuya

Background of Japan 3 layers administration –Central government: Ministry of Health, Labor and welfare –Prefecture(47): large area administration –Municipality (about 1800): water supply utility Large number of Water supply utilities: about 10000

Trend of service population and ration (Japan )

Number of Utilities etc. (Large scale water supply/Bulk water supply/Dams) Dam

Water Resource Quantity (million m3/year) River3581(54%) (27%) Dam756(11%) (44%) Lake56(1%)190224(1%) River- bed 947(14%)738611(4%) Well935(14%) (21%) Others378(6%)488478(3%) Total

To ensure quantity Issue –Large number of bodies concerned –Multi purposes for water resource development (not only water supply but also agriculture, industry, electricity …..) Key of success –Water resource development: Set only one special organization (owned by Central Gov.) –Water supply: gave prefectures “new role” as bulk water supply and it’s cost management

Water supply management Change for role of administration body Municipality Water supply management Water resource Water treatment Distribution Charge/Cost management Municipality Water treatment for one’s water resource Distribution Charge for people Prefecture Water treatment Cost management (for water resource development) Specialized Organization (Central gov.) Water resource development Multi purpose management Cost assistance (Subsidy/loan)

To ensure Quality Fusion environment and water supply –Set the Common target : environment quality guidelines –Environment administration automatically work for water supply Example : River Lank AA : BOD 1mg/l simple or slow sand filtration Lank A :BOD 2mg/l rapid sand filtration Lank B :BOD 3mg/l advanced water treatment

Improvement of water quality and environment protection Setting Environment guideline Effluent limitation in all Japan Strengthening effluent Limitation

Issues for next stage in Japan Making large scale water supply utility –Integrating bulk water supply and municipality’s water supply utility Correspond to population decrease Less energy water supply replacement KEYWORDS of Next Water Supply System Safety, Reliability, Stability, Environment and International