Significance of rainwater and reclaimed water as urban water resource for sustainable use Hiroaki FURUMAI Professor, Research Center for Water Environment Technology University of Tokyo Japan-China-Korea Green Technology Forum @ Tokyo, March 14, 2012 1 Outline Introduction - Climate change and fluctuation of annual rainfall in Japan - Water resource and water supply system in Tokyo - Concern about the sustainability of urban water use - Facility installation for rainwater and reclaimed water use Urban water resources for sustainable use - Rainwater harvesting and use Representative cases and new movement of rainwater use - Reclaimed water use and treatment technology Current state of reclaimed water use and new projects Japan-China-Korea Green Technology Forum @ Tokyo, March 14, 2012 2 Fluctuation of annual rainfall and occurrence of drought in Japan (mm) 2,100 Average annual rainfall decreases by about 7% in 100 years 2,000 1,900 1,800 1,700 1,600 1,500 B Annual rainfall 1,400 C H Annual rainfall J 年降水量 D 1,300 Moving average A G K for５年移動平均 5 years 1,200 E Tendencyトレンド F I 1,100 1900 1905 1910 1915 1920 1925 1930 1935 1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Fluctuation becomes larger A: Lake Biwa drought(1939), B: Tokyo Olympic drought(1964), C: Nagasaki drought(1967), D: Takamatsu drought(1973), E: Fukuoka drought(1978), F: Nationwide winter drought(1984), G: West Japan winter drought(1986), H: Metropolitan area drought(1987), I: Japan Islands drought(1994), J: Matsuyama drought(2002), K: Chubu and Shikoku area drought(2005) 3 Surface water dependent Water resource and Dam storage type Water supply system in Tokyo One-through water use Drinking water treatment plant Wastewater Treatment Plant 80% 20% <1% Japan-China-Korea Green Technology Forum @ Tokyo, March 14, 2012 4 Concern about the sustainability of urban water use Increased water demand had led to the dam construction at the upstream and the extensive water withdrawal from rivers in Japan. Stable water supply and efficient water use have become concerning in growing mega cities in Asia. Efficient water use have been implemented to reduce water intake from natural water system and to secure the sound water cycle. Achievement of the sustainability is required ensuring a long-term water supply with adequate quality and minimizing adverse economic, social and ecological impacts. Japan-China-Korea Green Technology Forum @ Tokyo, March 14, 2012 5 Facility installation for Rainwater and Reclaimed water use Reference: White paper on water resouces in Japan (2009) 350 3,289 3500 Total : 3289 facilities in 2007 300 3000 250 2500 200 2000 150 1500 Rapid increase 100 1000 50 500 0 0 1969 1974 1979 1984 1989 1994 1999 2004 Number of installed facilities per year facilities installed of Number Accumulated number of installed facilites installed of number Accumulated Years The number of facilities has been increased since 1980s, in which government financing system was introduced. Rainwater harvesting facilities: ap. 1600 in 2007 6 Milestones of rainwater harvesting (RWH) facility 3 3 Sumo-wrestling Arena Tank Capacity of 1000m (effective vol. 750m ) ( Kokugi-kan) 1984 Tank Capacity of 3000m3 1000m3 for flood control Tokyo Sport Stadium 1000m3 for miscellaneous water use (Tokyo Dome) 1988 1000m3 for emergency water use such as fire events 7 Representative examples of large-scale rainwater harvesting (RWH) in stadiums and domes Storage Roof Constructe Name of facilities capacity catchment d year (m3) area (m2) New Hiroshima Stadium 2009 1,000 23,000 Saitama Stadium 2002 2001 3,250 29,000 Saitama Super Arena Nagoya Dome Saitama Super Arena 2000 1,200 28,000 Sendai Dome 2000 1,300 19,800 Yokohama Stadiuam 1998 2,000 30,000 Tajima Dome 1998 3,000 19,000 Kitakyushu Media Dome 1998 2,000 22,000 Nagoya Dome 1997 2,800 35,000 Osaka Dome 1997 1,700 31,400 Ohdate Extensive forest Tokyo Dome Osaka Dome 1997 4,320 21,000 Dome Fukuoka Dome 1993 2,900 34,000 Izumo Dome 1992 1,210 36,000 Akita Sky Dome 1990 1,200 12,000 Green Dome Maebashi 1990 1,120 20,000 Tokyo Dome 1988 1,000 15,700 Yokohama Stadium Fukuoka Dome 8 Recent RWH project at a stadium in Hiroshima 東 再利用水槽Recycle water Water treatment and （１千立方メートル）reservoir (1000 m3) 水処理及び消毒設備sterilization facility Hiroshima 南 北 雨水貯留水槽Rainfall reservoir （１万４千立方メートル）(14000 m3) Installed storm water reservoir under the stadium mitigates urban flooding and utilizes rainwater for watering, toilet and water amenity. Promotion display Rainfall on the ballpark is recycled for flushing toilet. *Water for hand-washing is tap water. Sprinkling of water on the Flush toilets Water channel/stream baseball field 9 New watering technology in a new Sony building using ceramic pipe as louver Elastic binder Aluminum core material Rainwater Ceramic pipe with high performance of water retention Reduction effect on Surface Cooling device temperature simulated by Completed in 2011 Nikken Sekkei Ltd 10 Reclaimed water use in Japan The annual treated wastewater is 14.4 billion m3 in Japan. 1.4 % of the treated wastewater is reused. Directly supplied to business establishments, etc Water for toilet 3.7% flashing Industrial water 0.9% 8.0% , Agricultural water Water for 7.0% landscapes 修景用水 27.4% Reuse amount 200 million Snow melting 21.6% m3/year Water for water (FY 2009) recreational use 1.9% River flow maintenance 29.2% 11 Applications of reclaimed water in Tokyo Water source for revival Miscellaneous River maintenance of Meguro River, etc. about 68,000m3/day waters Tokyo Metropolis before after [Population:8.45 million] Water for toilet flushing in West- Shinjuku and Nakano Sakaue areas, etc.：about 9,300m3/day Miscellaneous Recreational Use Conventional waters Ochiai Water Reclamation Center activated sludge Cleaning water for train systems, activated sludge SESERAGI NO SATO：about YURIKAMOME：about 1,800m3/year process 16,000m3/year + Sand filtration or Membrane treatment & Ozone treatment Total: about 78,000m3/day 12 Reclaimed water use in skyscrapers in Shinjuku, Tokyo Large-scale recycling Elevated water tank Tap water Sewage Treatment Plant Disinfection Distribution Tank Reclaimed wastewater Secondary treatment Advanced treatment River Double pipe-supply system and Closed loop use Japan-China-Korea Green Technology Forum @ Tokyo, March 14, 2012 13 Ochiai Water Reclamation Center Rapid Sand Filtration Process 落合水再生センター Kanda River Shinjuku Subcenter Japan-China-Korea Green Technology Forum @ Tokyo, March 14, 2012 14 Reclaimed water use for restoration of water environment and aquatic amenity In 1989 In 1984 Off-site use of reclaimed water use 10,000m3/d (Max) 15,000m3/d (Max) Nobidome Senkawa Megura River In 1995 86, 400m3/d (Max)=1.0 m3/s Needs of stream flow and urban water amenity Japan-China-Korea Green Technology Forum @ Tokyo, March 14, 2012 15 Water reclamation project at Tokyo Shibaura Water Reclamation Center Secondary effluent Supplied area: 376 ha No. of buildings supplied: 60 Supply :ap. 3,900m3/day Sand Biological Biological Treatment area filtration Filtration Filtration 5,000m3/day Ozonation Ozonation Tokyo Shibaura Water Reclamation Center Flocculation Ozone Ceramic resistant membrane membrane 4,300m3/day 7,000m3/day Charge 260JY /m3 Max14,900m3/day Flush toilet water, spray water, cleaning water, and water for landscape etc. 16 Biological Filtration, Ozonation and Ceramic Membrane Technology (example in Tokyo) A highly durable ceramic filter ensures steady production of reclaimed water Biological filtration Ozonation Coagulation/flocculation・ ・Nitrification ・Improvement of Microfiltration ・Suspended solid removal micro-flocculation ・Coarsening of microfloc to prevent ・Color removal membrane fouling ・Odor removal ・Removal of contaminants and Reclaimed microfloc ・Disinfection water Secondary effluent Coagulant Biological filter Ozone Reactor Feed Coagulation/ pump Ceramic flocculation Ceramic membrane- basin module Blower Ozonizer 17 Water reclamation project at Sampo WWTP in Skai City Media added ASP + Fiber filtration=>MBR ¾Reclaimed water use for watering in the national football training center, and toilet flushing water for buildings and industrial water for factories and incineration plant. NTC Core wide-area (Sakai Soccer National Training Center) disaster- preparedness Ozone Water pump center Ozone treatment facilities treatment facilities facilities Sambo Sewage Treatment Plant Commercial/amusement facilities Large-scale company cluster Sakaihama Small- and Medium-sized Business Cluster 3 Incineratio Charge 20, 40JY /m n plant Supply area: 300 ha water Advanced treated water Supply capacity: Max 34,000 m3/day line ozonated water 18 Applications of reclaimed water in a medium- scale community (Tadotsu Town) Recreational Use Agricultural Use Discharge into agricultural farm ponds：2000m3/day （During June – September ） Gentle stream Activated carbon adsorption Small water park Sand filtration, Conventional activated AC adsorption sludge process + Ozonation Ozonation+ activated carbon adsorption Activated carbon adsorption recreational water ：20m3/day Groundwater Recharge Recharge to groundwater, the Tadotsu principal water source of Tadotsu Town 3 Town：2000m /day [ Population:24,000] 19 WQ standards for reclaimed water use Established in 2005 Use and Toilet Landscape Sprinkling Recreational use Water Quality flushing use T. coliform E.coli N.D./100mL N.D./100mL N.D./100mL 10CFU/mL Turbidity ≦2（target value）≦2 pH 5.8～8.6 Appearance Not unpleasant Color －－≦40 ≦10 Odor Not unpleasant Chem. Treatment Sand filtration