Page Top

Start Content

Morigasaki Water Reclamation Center

Photo:Morigasaki Water Reclamation Center

Morigasaki Water Reclamation Center is the largest water reclamation center in Japan that is organized with two facilities in the east and west. The treatment area includes the whole area of Ota-ward, most of Shinagawa-ward,Meguro-ward, Setagaya-ward, part of Shibuya-ward and Suginami-ward, consequently the whole area amounts to 14,675ha. That equals to the one-forth of the whole ward area. Also it accepts wastewater from Nogawa treatment area in Tama-district. The treated water is discharged to Tokyo Bay. Some wastewater is filtrated with the sand and used for washing or refrigerating machines of the Center and for toilet water, and also supplied to Ota Waste Incineration Plant. The generated sludge is pumped through pressure pipelines to Southern Sludge Plant with the sludge sent from Shibaura Water Reclamation Center.

Treatment area map


Operation started April 1966(stormwater drainage)
April 1967(water treatment)
Site area 415,309m2
Treatment capacity 1,540,000m3/day
Sludge treatment facilitiesThickeners 3
Digesters 4
Sludge elutriation tank 1
Stormwater storage tank 26,000m3
Storage tank in wet weather 118,000m3
Water treatment facilities
(Western facility)
Grit chamber 28
Primary sedimentation tank 11
Reaction tank 12
Secondary sedimentation tank 24
Water treatment facilities
(Eastern facility)
Primary sedimentation tank 18
Reaction tank 11
Secondary sedimentation tank 20

Average 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
BOD 150 130 3 6 -
COD(Mn) 75 68 7 8 35 or bellow
Total nitrogen 29.4 26.5 11.0 11.3 30 or bellow
Total phosphorus 3.2 2.9 0.9 1.7 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 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

Improvement of Living Environment through Wastewater Treatment

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

Illustration:Improvement of Living Environment through Wastewater Treatment

Preventing Flooding through the Removal of Stormwater

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 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

Ground plan

Ground map of the center

Characteristics of Morigasaki Water Reclamation Center

Generating business uses methane gas - First introduction of PFI as domestic sewerage works -

Image of regular generating by biomass

Photo:Gas-engined generator

Gas-engined generator

Photo:Sodium-sulfur battery facility

Sodium-sulfur battery facility

Sludge generated in wastewater treatment method is warmed in the digester, then organic substances in the sludge become methane gas and the amount of sludge is reduced. *1

22.8 kWh of electricity annually has been generated by using methane gas, the biomass energy *2, as fuel for generating facilities.

Regarding installation and management of the generating facilities, we introduced PFI *3 first domestically in sewerage works. It leads to cost reduction of facility building or maintenance/management.
Also it is transferred to a third party through Tradable Green Certificates as environmental valued energy.

※ Started in April 2002

*1: To warm up the sludge, warm water from generating facilities and waist heat warm water from Southern Sludge treatment plant is used.

*2: Recyclable energy generated by the creatures

*3: PFI(Private Finance Initiative)
PFI is the method that absorbs private funds, technics and management ability to public works.Inexpensive power is secured by applying private know-how by PFI at Morigasaki Water Reclamation Center.

Micro hydraulic power stations

Photo1:Micro hydraulic power stations

Photo2:Micro hydraulic power stations

Illustration:Micro hydraulic power stations

The outfall for the treated water is installed several meters higher than the sea level to protect from flood tide. There are 3 stations that generate around 800,000kWh electricity/year using the discharging gap(that equals to electricity consumption for 230ordinary households).  Hydropower generation is capable to generate more stably than solar power generation or wind power generation. Moreover, it is the clean energy that does not emit greenhouse gas causes global warming. Also it is transferred to a third party through Tradable Green Certificates as environmental valued energy.

※ Operation started: June 2005

Solar photoelectric Generation

There are no tall buildings around the Eastern facility of the Center,and therefore 4,480 sheets of solar cell modules of 250 W have been installed on the shelter coverings of the openings of reaction tanks. The maximum power output is 1MW,and the power of 1.15million kWh(equivalent of the power consumption of 330 households) is obtained annually.

※ Operation started: April 2016

Hydraulic power generation and solar photoelectric generation are the sources of clean enegy,which does not emit greenhouse gases such as carbon dioxide.
These kinds of power generation reduce 950 tons of carbon dioxide annually,contributing to the reduction of environmental load.


Guide map


West series
5-2-25, Ohmori-minami, Ota-ku, Tokyo 143-013(office)MAP

East series
2-5-1, Showajima, Ota-ku, Tokyo 143-0004 Tel : 03-3744-5981 MAP 

Access Terminal station of Keikyu Bus(for Morigasaki)from Ohmori station orKamata station on JR line
No thoroughfare for vehicles between East site and West site.

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
  • 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.

Hours:9AM~5PM(weekdays only)

End Content

Start User Guide

End User Guide