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2018/12/11 ADBI has released a Policy Brief Paper recommending maintenance based on the Johkasou Act

ADBI has released a Policy Brief Paper recommending maintenance based on the Johkasou Act

On December 6, 2018, "Institutional Mechanisms for Sustainable Sanitation: Learning from Successful Case Studies"

was published from ADBI (*).


 Please Download from Here.


In this Policy Brief, ADBI has taken up the performance evaluation test system of the johkasou in Japan

and the Johkasou Act (**) which stipulating the installation and maintenance of the johkasou as a good example.

This Policy Brief will be expected to strengthen the sanitation and wastewater treatment system of Asian countries in the future.

This Policy Brief was prepared based on the discussion in "Development Partner Roundtable and Policy Dialogue Session on Sustainable Sanitation in Asia", which has held at the ADBI Tokyo from 20th to 22nd September 2018. Approximately 40 people including 9 government officials from Asian countries and 25 staff of international organizations (***) participated in this session.


In this session, Mr. Hashimoto, an advisor of Japan Sanitation Consortium (JSC), made a presentation entitled "Institutional Mechanisms for Sustainable Sanitation: Lessons from Japan for other Asian countries" introducing on the Japanese management system of the decentralized wastewater treatment facilities related to the Johkasou Act. 

Also, Mr. Kumokawa from Japan Education Center of Environmental Sanitation (JECES) appealed the Japanese Johkasou system to the participants using the brochure " Night Soil Treatment and Decentralized Wastewater Treatment System in Japan " published by Ministry of the Environment. 


In addition, On September 22, 2018, site visits tour was held by ADBI. At this site visit tour, thanks to Goto Eisei consultant Co., Ltd. located in Kumagaya city, Saitama Prefecture, they kindly demonstrated for the participants a maintenance work and a desludging work at the johkasou site.

By observing the actual inspection and desludging work, participants seemed to well understand of the johkasou. Participants made a wide range of questions, including not only the treatment principle of the johkasou and the management technology, but also the principle of maintenance cost and the charge collection method.




(*)ADBI; The Asian Development Bank Institute was established in 1997 in Tokyo, Japan, to help build capacity, skills, and knowledge related to poverty reduction and other areas that support long-term growth and competitiveness in developing economies in Asia and the Pacific. ADBI also makes policy proposals to Asian countries.


(**) Johkasou measn packaged aerated wastewater treatment plant (PAWTP). From the early 1980s onward, the pollution of public water bodies caused by gray water became highly visible. In 1983, the Johkasou Act (PAWTP Act) was enacted to overcome this situation.

(***) Asian Development Bank (ADB), Japan International Cooperation Agency (JICA), International Water Association (IWA), Water-Aid, Bill & Melinda Gates Foundation (BMGF), World Bank etc.


Situation of the Session



Participants got lecture on the maintenance works of the Johkasou.



At the front of a vacuume car.