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Mikawashima Water Reclamation Center

photo:mikawashima water reclamation center

Mikawashima Water Reclamation Center is the first modern sewage treatment plant in Japan. In the Center, there are ample greenery, and many cherry blossoms, which make scenic beauty in spring with the red brick facilities of Pumping Station at the Former Mikawashima Sewage Disposal Plant. The treatment area includes the whole area of Arakawa Ward, Taito Ward, most of Bunkyo Ward, Toshima Ward,part of Chiyoda Ward, Shinjuku Ward and Kita Ward, consequently the whole area amounts to 3,936ha.
The treated water is discharged to Sumida River. A part of the treated water is further cleaned by filtration at Higashi-Ogu Purification Center and discharged to Sumida River. Some part is used inside Mikawashima Water Reclamation Center for washing and cooling machines.
The generated sludge is pumped through pressure pipelines to Tobu sludge plant for treatment.
We hold the "Cherry blossoms Festival" every spring.

Illustration of mascot

Mascot of Mikawashima Water  Reclamation Center

Illustration of  treatment area of mikawashima water reaclamation center



Operation started March 1922
Site area 197,878m2
Treatment capacity 665,000m3/day
Wastewater treatment facilitiesGrit chamber 21
Primary sedimentation tank 18
Reaction tank 14
Secondary sedimentation tank 32

Average quality of influent and final effluent

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
Ogu seriesAizome seriesAsakusa seriesEffluentHigashi-ogu
BOD 130 170 150 9 3 25 or bellow
COD(Mn) 79 94 78 11 8
Total nitrogen 30.6 35.7 34.4 16.2 16.9 30 or bellow
Total phosphorus 3.2 3.5 3.5 0.3 0.1 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 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.

Sewerage System Components

The Role of Tokyo Sewerage

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.

Water Quality of Public Water Bodies

Ground plan

Illustration of Ground plan

Features of Mikawashima Water Reclamation Center

Pumping Station at the Former Mikawashima Sewage Disposal Plant

The red brick pump pit that started operation in March 1922 was imitially a symbolic facility of the Water Reclamation Center. However , this service was replaced with another  pumping station on a separate line in March 1999 and abolished.

In December 2007, the Pumping Station at the Former Mikawashima Sewage Disposal Plant was designated as a National Important Cultural Property(Building), the first in the field of sewerage system, since "it has high historical value as the representative remains of the Former Mikawashima Sewage Disposal Plant, which was the first modern sewage treatment plant in our country, and a series of  well-preserved structures such as chambers and grit chambers that still remain in the facility are quite valuable in understanding the construction of a pumping station at a modern sewage treatment plant"

It has been open to the public since April 2013. A tour is available between 9 a.m. and 5 p.m.,excluding Tuesday, Friday, the year-end and New Year holidays, by advance reservation only. For reservation, please call 03-6458-3940(Japanese only).


Cherry blossoms and Facilities




Pump pit


Pump well connection

History of Mikawashima Water Reclamation Center

Mikawashima Water Reclamation Center was begun to build from 1914 and the operation started in March 1922, as the first modern sewage treatment plant in Japan.
The center has been operating with various wastewater treatment processes, which are the Tricking filter process (taking in air by the paddle rotation)(1936), and the Diffused conventional activated sludge process(1961).


Tricking filter process


Paddle type

Arakawa Sizen Park

We provide the above-ground space of Mikawashima Water Reclamation Center as a park in Arakawa ward. This park consists of two parts in the north and south(6,100m²) and was selected as one of "New Tokyo 100 Views". There are also baseball field, tennis court, children's park and traffic garden.


Pond in the park

Guide map

Address 8-25-1 Arakawa, Arakawa-ku MAP
Access 13 minutes walk from Machiya sation (Tokyo Metro Chiyoda Line or Keisei Line)
 3 minutes walk from Arakawa-nichome station  (Toden Arakawa Line)

Illustration of a guide map

Tokyo Sewerage Museum "Rainbow"

Tokyo Sewerage Museam Rainbow
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: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"

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

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.


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