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Sunamachi Water Reclamation Center

Photo:Sunamachi Water Reclamation Center

Starting operation in 1930, Sunamachi Water Reclamation Center is the second oldest Water Reclamation Center in Tokyo. Sunamachi treatment area is a delta area surrounded by Sumida River and Arakawa river.

Sunamachi Water Reclamation Center is treating the sewer generated from the vast zone of 6,153ha which consists of all of Sumida Ward, most of Koto Ward, and a part of Minato Ward, Shinagawa Ward, Adachi Ward and Edogawa Ward with the Ariake Water Reclamation Center.

The treated water is discharged to Tokyo Bay. A part of the treated water is cleaned through sand filtration and used inside the center for cleaning facilities, cooling machines, and flushing toilets.

The generated sludge is carbonized and incinerated at Tobu Sludge Plant in the Center.

Treatment area map


Operation started February 1930
Site area 827,033 m2
Treatment capacity 658,000 m3/day
Wastewater treatment facilitiesGrit chambers 46
Primary sedimentation tanks 21
Reaction tanks 24
Secondary sedimentation tanks 20
Sludge treatment facilitiesThickeners 7(3)
Storage tanks 7(4)
Thickeners 12(12)
Dehydrators 10(10)
Incinerators 3(3)
Sludge carbonization facilities 2(2)

The digits in the brackets belong to Tobu Sludge Plant.

Storage tank in wet weather 85,600 m3
Stormwater storage tankPumping station 33,000 m3
Ex-Kiba line 55,000 m3

Quality of influent and final effluent

The final effluent from the water reclamation center complies completely with the water quality standards of the Tokyo Metropolitan Environmental Security Ordinance and is sufficiently clean for fishes to live in.


ItemInfluentFinal effluentRegional water quality standards, ordinance
BOD 180 5 -
COD 100 10 35 or bellow
Total nitrogen 33.7 9.9 30 or bellow
Total phosphorus 4.0 1.4 3 or bellow

Average values of 24-hour test conducted in FY2018

※ The higher values of BOD and COD indicate the higher levels of water contamination. BOD describes the amount of oxygen required by microorganisms to eat organic material in water, and COD describes the amount of oxygen required by oxidizer to decompose organic material in water. The quality levels of discharged water are specified in terms of BOD for rivers and COD for seas. Total nitrogen and total phosphorus are closely related to the generation of red tides.

Sewerage System Components

The sewerage system is principally made up of 3 facilities.
Sewers, which collect and carry wastewater.
Pumping stations, where wastewater is pumped up so that the sewers do not get too deep.
Water reclamation centers, where wastewater is treated to be clean water.
Inspections, cleaning, and repairs are done daily in order to make sure each of these facilities works properly.

Illustration:Sewerage System Components

The Role of Tokyo Sewerage Systems

Improvement of Living Environment through Wastewater Treatment

Wastewater discharged from homes and factories is treated to ensure a comfortable living environment.

Illustration:Improvement of Living Environment through Sewage Treatment

Preventing Flooding through the Removal of Stormwater

The city is protected from flooding through the speedy removal of stormwater on land surface.

Illustration:Preventing Flooding through the Removal of Rainwater

Protecting the Global Environment

We treat wastewater and discharge cleaned water, to carefully protect the water quality of rivers and the sea. We also recycle treated water and sludge, and utilize unused energy, as we work to build a recycling city.

Illustration:Protecting the Global Environment

Features of Sunamachi Water Reclamation Center

Minamisuna Stormwater Storage Tank is an institution for storing the stormwater collected from the area of about 500 ha(s), such as Sunamachi area in Koto-ward area, and aiming at mitigation of flood damage.

The stored stormwater is sent to Sunamachi Water Reclamation Center at the time of fine weather, and after processing, it is discharged to Tokyo Bay. Moreover, in order to use an institution effectively, the upper part of Storage Tank is used as public facilities, such as collective housing and a parking lot for bicycles.

Photo:The exterior of the Minamisuna Stormwater Storage Tank

The exterior of the Minamisuna Stormwater Storage Tank

Photo:The interior

The interior

Regional Air Conditioning Project in Shinsuna 3-chome Area

In Juntendo Tokyo Koto Geriatric Medical Center, the treated water of Sunamachi Water Reclamation Center and the waste heat of an incinerator or a carbonization furance are utilized as a heat source of hot water supply or an air conditioning.

Utilizing such unused energy makes the amount of discharge of CO2 less than using the electricity and any gas made from the fossil fuel, contributing to global warming prevention.

Sunamachi 3-chome regional air-conditioning


We reduce the electricity bill by using power in the daytime that was saved in the sodium-sulfur battery in the nighttime with low power rate.

Also we tackle with the power shortage caused by power demand control.

Photo:NaS Battery in Sunamachi WRC

NaS Battery in Sunamachi WRC

Environmental management of Sunamachi Water Reclamation Center

The Sun Square

There are biotopes such as a little stream in "The Sun Square" on the left side containing the main gate. Moreover, in front of "Shinsuna Otaki," there is a pond which is recycling treated water and the fishes such as carps are swimming in it.

Photo:The Sun Square

Ginkgo Road

There are about 200 kinds of 80,000 plants in the site of a vast center(its area equals to 20 Tokyo Dome), and there are also the ginkgo trees which were transplanted from former Tokyo Metropolitan Government Building's site, or the American aloes that bloom once in 100 years.

Photo:Ginkgo Road

The meeting for cherry blossoms viewing

We hold the meeting for cherry blossoms viewing in the flowering time for the residents in the district.

Photo:The meeting for cherry blossoms viewing

Shinsuna Sports Ground

We provide playground or open space on the above-ground space of Toyo wastewater treatment facilities for the residents in the district as Shinsuna Sports Ground in Koto ward for environmental harmony with the circumference and improvement in welfare.

Application available at Koto Ward Health Center(Tel: 03-3647-5402)

Photo:Shinsuna Sports Ground

You can enjoy playing soccer or tennis at the sports ground.

Guide map

Location 3-9-1, Shinsuna, Koto-ku, Tokyo Phone:03-5632-2180 MAP
Access 15 minutes walk from Minamisunamachi station east exit(Tokyo metro tozai line)

Illustration:guide map

Tokyo Sewerage Museum "Rainbow"

Tokyo Sewerage Museum Rainbow logo
There is a facility to enjoy the experience of learning about the sewerage system, its roles, and the importance of water environment.

  • Hours nine half o'clock to sixteen half o'clock
  • Entry Fee Free
  • Closed Mondays(open on holiday Mondays, closed the next day)and the New Year's season
    Open daily throughout the summer(July 16 - August 31)
    Open on Sewerage Day(September 10)and Tokyo Citizens Day(October 1)
  • Address 2-3-5 Ariake, Koto-ku Ariake Water Reclamation Center Management office(A-tower)5th floor
  • Telephone 03-5564-2458
  • Website Tokyo Sewerage Museum "Rainbow"

Bureau of Sewerage in Tokyo website

Tokyo Amesh

Tokyo Amesh is the system that shows rainfall in and around Tokyo in real time. The rainfall is measured by radars and ground rain gauges.

※ Tokyo Amesh is the registered trademark of the Tokyo Metropolitan Government.

Tokyo Amesh screen image

Virtual Sewerage

Animation and video are used to allow people to experience the sewerage system in a fun way that would not be normally possible.

click Virtual Sewer

Beware of croocked dealer who pretend to be related to the Bureau of Sewerage!

The Bureau of Sewerage does not rely on businesses to repair or clean drainage facilities in housing.

Facility tours of Water Reclamation Centers

Facility tours of water reclamation centers are available except weekends, holidays, and the New Year's season.
Please contact us about reservations and details.

Phone 03-3241-0944
Hours 9AM~5PM(weekdays only)

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