Page Top

Start Content

Ariake Water Reclamation Center

Photo:Ariake Water Reclamation Center

Ariake Water Reclamation Center is a separate sewage system water treatment facility. It is built in Tokyo maritime sub-city center's Clean Center. Its treatment area is part of the Sunamachi Treatment District(Tokyo maritime sub-city center and surrounding areas, and part of the landfill inside the central breakwater).

The Center adopts advanced wastewater treatment using A2O method(anaerobic-anoxic-oxic process)and biological filtration process, and discharges the treated water into Tokyo Bay(Ariake-nishi Canal). A part of the treated water is further cleaned using ozone before being used inside the Center for cleaning facilities, cooling machines, and is also used as water for flushing toilets in buildings in Tokyo maritime sub-city center.

The generated sludge is pumped through pressure pipelines to Tobu sludge plant for treatment.

Treatment area map

(As of April, 2020)

General data of the facilityOperation started September 1995
Site area 46,600m2
Treatment capacity 30,000m3/day
Water treatment facilitiesGrit chambers 2
Primary sedimentation tanks 3
Reaction tanks 2
Secondary sedimentation tanks 3
Biofilm filtration tanks 6

Average quality of intake and discharge water

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


ItemInfluentFinal effluentRegional water quality standards
BOD 190 1
COD(Mn) 100 9 15 or bellow
Total nitrogen 45.6 8.7 20 or bellow
Total phosphorus 4.7 0.2 1.0 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 Components

The sewerage system is principally made up of 3 facilities.
Sewers, which collect and carry sewage.
Pumping stations, where sewage is pumped up so that the sewers do not get too deep.
Water reclamation centers, where sewage 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 Sewage Treatment

Sewage 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 Rainwater

The city is protected from flooding through the speedy drainage of stormwater which falls on land surface.

Illustration:Preventing Flooding through the Removal of Rainwater

Protecting the Global Environment

We treat sewage and release 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

Ground plan

Illustration:Ground plan

Features of Ariake Water Reclamation Center

Advanced Wastewater Treatment Facility(A2O method)

Because of nitrogen and phosphorus hard to get removed by means of the wastewater treatment so far used, the red tides still appear in Tokyo Bay due to eutrophication. Hence, we are adopting an advanced wastewater treatment called A2O method(anaerobic-anoxic-oxic process)in order to remove larger amount of nitrogen and phosphorus.

Illustration:IAdvanced Wastewater Treatment Facility

Anaerobic tank

Wastewater and activated sludge are mixed here without air supply. Due to the lack of oxygen, the microorganisms in the activated sludge discharge the phosphorus that they have stored within themselves into the water.

Anoxic tank

The water from the aerobic tank containing nitrogen combined with oxygen is fed back to the water from the anaerobic tank. The microorganisms then take in the oxygen combined with the nitrogen and start breathing, while the nitrogen deprived of the oxygen gets released in the form of gas.

Aerobic tank

By blowing sufficient oxygen, the organic substance gets decomposed by microorganisms while nitrogen is combined with oxygen. Further, the microorganisms absorb more phosphorus than is released from the anaerobic tank.

Biological Filtration Method

The biological filtration facility has almost the same structure as the sand filtration facility, so that the suspended solids(SS)get removed through physical filtration. Further, air is passed through the bottom of the filter to create a film of aerobic microorganisms(biofilm)on the surface of the filter. This allows the biodegradable dissolved organics remaining in the raw water(treated wastewater using A2O method)to get adsorbed, dissolved and removed. In this way, cleaner treated water can be obtained.

Illustration:Biological Filtration Method

Supply of Reclaimed Water to Tokyo Maritime Sub-city Center Area

Ariake Water Reclamation Center supplies a part of the advanced-treated water as the reclaimed water to Tokyo maritime sub-city center area. The reclaimed water is effectively used for flushing toilets in buildings and for washing the vehicles of "Yurikamome", new transport system running through Tokyo waterfront area.

Photo:Base of Yurikamome vehicles

Base of Yurikamome vehicles

Treated wastewater is the water resource of the metropolitan city.It revitalizes the water.Thats our job.

Above-ground Space full of Sports Facilities

Most of the treatment facilities are installed underground, with the above-ground space used for gymnasiums, heated pools, and sport gyms of Koto-ward and Ariake Tennis Park. These facilities are used and enjoyed by a large number of people.

Photo:Above-ground Space full of Sports Facilities

Guide map


2-3-5 Ariake, Koto-ku, Tokyo 135-0063,
Phone: 03-5564-2033 MAP


8-minute walk from Odaiba-kaihinkoen Station on Yurikamome Line (Tokyo Waterfront New Transit).
13-minute walk from Tokyo-Teleport Station on Tokyo Waterfront Area Rapid Transit (Rinkai Line).
3-minute walk after getting off the Metropolitan bus to "Tokyo Big Sight" or "Tokyo Teleport" at "Ariake 1 chome" from Monzennakachou station on Tokyo Metro Tozai Line or Toyosu station on Tokyo Metro Yurakucho 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
  • Address:-3-5 Ariake, Koto-ku Ariake Water Reclamation Center Management office(A-tower)5th floor
  • Telephone:03-5564-2458
  • Website:Tokyo Sewerage Museum "Rainbow"

Tokyo Bureau of Sewerage

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 Sewer

Animation and video are used to allow people to experience the sewer system and wastewater treatment 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.


End Content

Start User Guide

End User Guide