Best Practice of Wastewater Reuse

in Japan

Hiroshi Tanaka, Director of Water and Wastewater Works,

Tadotsu-town, Kagawa Prefecture 1

Annual Wastewater Reuse Rate (2009)

Tadotsu from Japan

Japan as a whole Tadotsu

Wastewater treatment

1.69 million (m3/ y)

1.4%

60%

2

Wastewater treatment

14.3 billion (m3/ y)

Outline of Tadotsu Tadotsu from Japan

Japan

Tadotsu 3

Tokyo Osaka

Tadotsu

Annual Rainfall Tadotsu from Japan

4

Tadotsu

National Tadotsu

National

1994(Drought Occurred) Average in the past 30 years

678mm

1,142mm 1,068mm

1,557mm

Tadotsu from Japan

5

Drought in Sameura Dam (Storage Rate 0%)

6

reclamation

facility

wastewater

reuse

Tadotsu other

cities

WWTP

13,000m3/d

10,000m3/d

8,000m3/d 5,000m3/d

10,000m3/d

other

cities

Tadotsu from Japan

Agriculture River augmentation Groundwater recharge Recreation

Plan of Water Recycling Tadotsu

2 Process by reuse Tadotsu from Japan

7

Recreation 45m3/D

Agriculture, Groundwater

Recharge, etc 9,955m3/D

Rapid Fiber

Filtration

Ozonation ＋ ＋

Activated Carbon

＋ ＋ Chlorine Disinfection

Rapid Fiber

Filtration

Activated Carbon

Agricultural Use Tadotsu from Japan

8

Agitator

Reclaimed water

To rice paddy & farmland

Agitator

Reservoir

natural water 8

Dilution and Agitation

Reservoir

Reservoir

Tadotsu from Japan

9

Groundwater Recharge RO Membrane Facility

Drinking water

Reclaimed water

Salt water intrusion control

Drinking Water

Difficult Points in Project • Budgeting and accountability

Total ¥3.5 billion project, contribute

¥1.4 billion from my town

• Consensus with citizens Agreement from 1,300 farmers

• Public relations events Seminar and farming experience, etc

10

Tadotsu from Japan

Public relations events

11

Tadotsu from Japan

Seminar for farmers

farming experience

• Reduce drought risk Secure water resources

• Conserve water environment Rivers augmentation

• Create comfortable open space Recreation parks

• Role model for reuse

12

Tadotsu from Japan

Outcome of Project

• Make a master plan for wastewater reuse to meet the needs

• Set treatment goals by reuse

• Mayor’s strong leadership

• Improve communication through wastewater reuse with citizens

13

Tadotsu from Japan

Proposal

Thank you very much for your attention!

Tadotsu from Japan

14

MLIT award, 2010