A Series of International Activity Reports in the Materials Cycles Division

Activities of Decentralized
Domestic Wastetwater Treatment
in ASEAN countries

National Institute for Environmental Studies
The National Institute for Environmental Studies (NIES) is the only institute in Japan that engages in awide range of environmental research in an interdisciplinary and comprehensive manner. Our instituteconsists of eight areas, and since its establishment in 1974, we have been working in various ways on
environmental issues in Japan and overseas.
Above all, in the Material Cycles Division, one of the goals is to solve the waste-oriented problem, which
is a negative aspect of production and consumption activities, and we also take on the challenge ofpromoting the transition to a society where efficient use of resources and sound material circulation
are ensured. International activities include research that contributes to the realization of a sustainable
society in Asia and to the establishment of joint solutions to global environmental problems.

2Waste management research collaboration and research
into practice projects with Asian countries（〜FY2020）
Until FY2020, the International Support Office for Resource Recycling and Waste Research has been
conducting research on waste and resource management in collaboration with Asian researchers andbuilding a foundation for disseminating the outcome as an international collaboration. As a major
contribution, the findings and knowledge obtained were efficiently provided to international organization(IPCC, UNEP, etc.) activities, and contributed to the issuance of policy proposals and guidelines. In
addition, through participation in international standardization activities at ISO, we have formed a teamthat is at the core of a series of work aimed at the implementation and establishment of research resultsin society. In cooperation with local researchers, we have delivered proposals and reports to government
officials, published technical guidelines, and carried out public relations activities related to improvementof waste management in Asian cities (Bangkok, Jakarta, Hanoi, etc.).

International Partners with MOU agreement (2001-Present)3

International Waste Management
Research Administration Office（FY2021〜）
Under the new institutional framework from FY2021, we will further strengthen strategic partnerships withrelated organizations in Japan and overseas, and accumulate knowledge and experience on methods
for social implementation and dissemination of research outputs in the Asian region. This will contributeto the development of policies and technologies in the region based on scientific evidence in the area ofmaterial cycles and waste management. The specific activities are as follows.				
			1) Building an international cooperation/collaboration network
By collaborating with international organizations and overseas institutions and local governments,
we identify needs for the involvement of academic experts at an early stage, and aim to increase
opportunities for substantial policy contributions.
2) Coordinating international joint research projects
We support the smooth implementation of research activities in their entirety, such as the start-up
process, research progress management, and dissemination of outputs, for joint projects with overseas
universities, institutions, and international organizations.
3) Supporting social implementation of international research results
The office serves as a liaison for promoting the implementation of research output, such as contributions
to international standardization activities, issuance of technical guidelines or policy briefs, and technicalsupport for Japan infrastructure exports by combining researchers’ scientific expertise.
4) Disseminating and publicizing research output
By hosting and co-sponsoring international events, we encourage dissemination of research results
effectively. Academic papers, reports, and policy briefs are publicized via official press release and social
media. We also expand the use of digital deliverables such as databases and application software thatare developed through the research activities.

4Dr. Masahiro Osako, Dr. Masato Yamada, Dr. Tomonori Ishigaki, Dr. Yoshitaka Ebie, Ms.Rieko Kubota
Dr. Kazuaki Syutsubo, Dr. Tomohiro Okadera
Secretariat team
Mr. Koji Otsuka, Mr. Atsuhiko Yoshimura, Ms. Risako Nogami, Ms. Yoko Hagiwara,
Ms. Kikuko Muroya, Ms. Kae Inaba, Ms. Itsuko Saito, Ms. Akemi Koike

About PoDIWM

To obtain the detail of the project
https://www-cycle.nies.go.jp/eng/report/pdf/podiwm.pdf

PoDIWM, which stands for Policy Dialogue and Network Building of Multi-Stakeholders on Integrated
Domestic Wastewater Management in ASEAN Countries, is a project jointly operated by the Ministry of
Public Works and National Housing of the Republic of Indonesia and NIES. It aims to serve as the basis
for policy and institutional design and development for multiple stakeholders regarding the introductionof decentralized management and treatment technology for domestic wastewater. Nine countries among
ASEAN Member States (AMSs), excluding Singapore, have been participating in this project to improve
the AMSs’ domestic wastewater management. Rapid population growth and changes in people's lifestyles
and behaviors have deteriorated water quality and ecosystems, resulting in a serious negative impact
not only on public health, but also on the aquatic environment, including groundwater, surface water, andcoastal and marine water. Inappropriately discharged domestic wastewater can cause enormous damage
to industries such as fisheries, water transportation, and tourism, yet national and local governments are
not very conscious of the urgent need for appropriate management. This has led to a lack of institutional,
economic, social, and technological development in this field in AMSs.
To address these problems, PoDIWM conducted an assessment survey of the legal policy system andtechnical status of domestic wastewater management in participating countries. Through successive
meetings, workshops, and dialogues in each country and regional events, invited national and local
stakeholders and experts have enhanced understanding of the results of local evaluation and have
improved communication on the effectiveness of a decentralized system for domestic wastewater
management in this region. Outputs were delivered to develop a selection tool of sustainable treatment
technology for domestic wastewater. Performance testing methods for decentralized facilities in
the ASEAN region are being harmonized by a round-robin test that took place in different conditions
in participating countries. All members from AMSs and other international/regional stakeholders
collaboratively made proposals for policy drafts and action plans tailored to each country's situation.
At the end of the project, all project members agreed to issue a regional policy recommendation andcollective commitment to achieve sustainable and integrated domestic wastewater management.

Decentralized domestic wastewater treatment
Domestic wastewater contains undesirable contaminants and unsafe biological pollutants in terms of
public health and environment and typically exhibits different features from commercial and industrial
wastewater. Regardless, many potential pollutants can be present in domestic sewage, from domesticallyavailable chemical products or pharmaceuticals that can be easily disposed of via toilets, sinks, drains,etc.
When the domestic wastewater issue is discussed, we should take into consideration both blackwaterand greywater, which are different in nature. Blackwater is wastewater that has come into contact withhuman waste, whereas greywater is defined as untreated wastewater that has not come into contact withhuman waste. Sources of greywater include wastewater from bathtubs, showers, clothes washing, etc.
In general, urban facilities that treat domestic wastewater firstly target blackwater because of the strong
unpleasant feeling people have for it, though greywater also possesses a nonnegligible impact.
A decentralized treatment facility purifies wastewater by using microbial activities to make it clean todischarge. It is the most familiar type of treatment facility and is compact, allowing it to be installed on
the premises of households.
A decentralized system offers the following advantages:
1. Less costs required; in terms of investment cost and operation and maintenance costs.
2. Better protection of water resources, less impact in case of accident (risk minimization)
3. Better adjustment to the individual quality of wastewater
4. Flexible (expandable) and adaptable to changing operational conditions
5. Providable tailor-made solutions for environmentally sensitive areas
6. Better fit into the landscape
7. Easier management and reuse of treated water and nutrients (e.g. nitrogen and phosphorus)

7

Development of stakeholders network
Since issues related to domestic wastewater management are varied and cross several related domains,
it has been difficult to realize a shared sense of them among relevant stakeholders, especially government
officials. PoDIWM addresses such coordination between line ministries and related stakeholders byorganizing a task force team in each AMS, consisting of various officials in the related sections fromnational to local levels, as well as academic experts. The task force team members are mainly called fromthe respective parties, including those responsible for national development plans; those responsible fordomestic wastewater treatment; those responsible for the environment; those responsible for construction
standards; standardization organizations; local government representatives; academic researchers in thefield of domestic wastewater treatment; plant manufacturers, etc. Domestic task force teams hold regularmeetings to share the findings and to discuss future directions. The common understanding and synergies
among task force members thus serve to strengthen the foundation for collective policy proposals fromrespective member states and contribute to leveling.

8Capacity-building activities
Implementation of new technology is not only limited to introducing and starting a facility but also includes
operation and management schemes required for maintaining performance capabilities. Development ofadministrative direction (governance) capacity and operational testing skills is necessary for sustainable
management of urban domestic wastewater. To raise awareness of each country’s task force (CTF)
members and to develop human resources, we provide training opportunities in Japan to deliver lectures on
the dissemination of domestic wastewater management policies, systems, and technologies, to exchange
opinions among related parties, and to visit decentralized facilities and laboratories where performance tests
are conducted. About 60 CTF members gathered at the training site from the ASEAN region and engaged incapacity development training over a one-week period. The intensive training provided up-to-date informationon the national policy framework of domestic wastewater management, the essential mechanisms
guaranteeing the performance of decentralized facilities, the practices of implementation and practicaloperation of the decentralized systems in the local government, and international cooperation to distribute
rational technology and schemes. In parallel with the training, we held periodic domestic CTF meetings to
update individual knowledge by sharing data obtained from field surveys in each country and for opinion
exchange among stakeholders. This also led to the effective compilation of policy recommendations as wellas human resource development in each country.

9Regional policy dialogue
Two policy dialogues were organized as part of the project, with participants including CTF members andinvited international experts to discuss the future of domestic wastewater management and the measuresneeded in the ASEAN region.
In the first dialogue, which was held in Jakarta, Indonesia, the participants discussed the common andunique features of domestic wastewater management. Workshops by the breakout group deepened thediscussion toward the preparation of policy proposals and regional policy roadmaps for the dissemination ofdecentralized wastewater management in each country.
In the second policy dialogue, which was held online due to the influence of the COVID-19 crisis, the policy
recommendations and regional policy roadmap were finalized. ASEAN stakeholders had opportunities tocommunicate with international donors to learn how to attract investment in infrastructure development in
the domestic wastewater management field.
It is the nature of this project that multi-stakeholders from different countries and affiliations, who cannot
usually meet, gather and engage in communication beyond the stovepiped administration in this field.
This network of multiple stakeholders will enhance the collection, knowledge, and sharing of up-to-date dataon domestic wastewater and sanitation in the ASEAN region. Policymakers will receive valuable informationthat can serve as a basis for decisions. This is expected to yield environmental benefits in both the social andeconomic / public and private sectors.

10Outlook report by country
Although 59% of the population uses a centralized sewerage system, areas outside
urban centers are so remote that they do not have access to the centralized system.
Therefore, implementation and proper management of a decentralized system
are required. The Authority for Building and Construction Industry has issued aBruneiguideline for sanitation facilities for buildings to curb aquatic pollution by domestic
wastewater. In the future, it will be necessary to develop a public–private partnership
scheme to spread and to promote regular maintenance of decentralized facilities,
such as sludge removal and performance assurance with standard testing methods.
The state’s immediate goal is the integration of a decentralized system in suburban
and rural areas with an existing centralized system.

Since the administration of decentralized domestic wastewater management
crosses multiple ministries and departments, lack of information sharing andinadequate discussion on policymaking are concerns. This is a typical andrepresentative problem of the stovepiped administration (segmentation). Sub-decree

CambodiaNo. 235 is an important regulation of Cambodia enacted to clarify the role of eachministry, delegate operations to local governments, secure the rationale and safetyof treatment systems, promote public understanding and participation, and promote
investment by development donors and the private sector. Although building permits
based on the construction law regulate the requested sanitation capacity, thisdoes not harmonize with sub-decree 235. In the future, it will be necessary to makeadequate use of the existing law of sub-decree 235.
11

Outlook report by country
Access to sanitary management had already been improved, with about 75% having
decent access, 16% basic access, and 9% no access to wastewater treatment.
The wastewater treatment system is defined as on-site and off-site, rather thandecentralized and centralized. Based on the Ministry of Public Works and Housing’s

Indonesia

Regulation No. 04/2017, the on-site system is classified into individual andcommunal scale, while communal is divided into 2–10 houses and a public toilet.
In terms of sludge treatment, there are public septage treatment facilities in 281
regions/cities out of a total 514 regions/cities in Indonesia. Also, after the central
government has issued new and strict regulations on effluent standards, the local
government needs to update technologies, increase the O&M budget and number ofskilled human resources, and introduce maintenance procedures.

Building permits including those for sanitation facilities need to be obtained fromthe Provincial Department of Public Works and Transport according to the New
Agreement on Building Management No. 2241/ PWT, 2019. Decentralized systems
have been installed in 25 regions in Laos. The coverage area for improving domesticLaoswastewater management needs to be increased. As one of the most important policy
recommendations, the program on capacity development and awareness raising forpolicymakers strongly advised full-scale development of training mechanisms toenable total system design including maintaining wastewater treatment performanceand enhancement of wastewater discharge standards.

12

The national government has a target to distribute the central sewerage system
nationwide, but the actual situation showed a reasonable development of a combinationof centralized and decentralized systems. The centralized system, individual septic
tanks, and traditional system accounted for 60.2%, 16.7%, and 14.1%, respectively, of

Malaysia

person equivalent in 2017. The technologies currently used for decentralized systems
are individual septic tanks and small-scale sewage treatment facilities. Decentralized
systems are recommended in areas where households are not densely populated.
Malaysian Sewerage Industry Guidelines Volume 5 – Septic Tank, 3rd edition, isthe general standard for development of septic tanks, required for the design andconstruction of individual septic tanks. Standards on environmental quality, discharge
acceptance, and analysis methods need to be improved, and technological guidelines
to promote decentralized systems especially in the environmentally vulnerable water
catchment areas and remote suburban/countryside need to be developed.
In Yangon, Myanmar's largest city, wastewater treatment facilities are being actively
installed and adjusted technologically to suit local conditions. Several projects
are underway such as the formulation of a master plan on domestic wastewater
management and the expansion of a centralized sewerage system by 2027. But

Myanmareven in urban areas, the centralized system only covers 3.4%, and more than half the
population uses pit latrines. The Myanmar National Building Code and Guidelines
for High-Rise Building Construction Projects stipulate water quality standards fordrainage and effluent. For local staff it is difficult to evaluate the effectiveness ofthe technologies in terms of contributing to solving local environmental issues
in Myanmar. The capacity-building program for the stakeholders is therefore very
important to realize proper assessment of the technologies and promotion of theintroduction of the best available technologies in the country.

13Outlook report by country
Ninety-five percent of urban domestic wastewater flows directly into groundwater,
drainage systems, rivers, and other watersheds, or after minor treatment in poorly
functioning septic tanks, in the Philippines. To improve this situation, large urban
centers have been working on the privatization of water supply and sewage systems

Philippines

for efficient operation. However, Metro Manila faces the difficulty of putting this into
practice because it is not economically feasible for middle- to low-income households
to pay for sewerage connection and the associated monthly charge. Municipalities
with such financial constraints have seen increased interest in decentralized systems
based on economic benefits such as affordable cost, environmental benefits suchas functional and reliable performance, and social benefits such as sustainability.
The National Building Code (Presidential Decree No. 1096) requires that domestic
wastewater be discharged to the nearest sanitary sewer where available. If notavailable, it is to be disposed of into a septic tank / subsurface absorption field.
Clean water and sanitation conditions have greatly improved overall in the past two
decades. In contrast to considerable efforts to manage blackwater, about 70% of
greywater is discharged into water bodies without appropriate treatment. Decentralized
facilities are being installed nationwide to solve this situation. Ministerial regulations

Thailand

under section 8 of the Building Control Act addresses technical information regarding
the wastewater system. However, the building codes are designed from a safety andcivil engineering viewpoint and do not address the details of building occupancy andgenerated wastewater. The government will have to promote engagement of thecommunity in domestic wastewater management through the development of programs
that enable local governments to operate and maintain wastewater-related public
services and to raise awareness of regular maintenance of decentralized facilities.

14

Vietnam has succeeded in providing improved drinking water and sanitary facilities
to more than 90% of the population. To maintain the water environmental quality, adecentralized system is indispensable owing to the low availability of centralized systems
in local areas. Based on Decree 80/2014 and earlier ones, every household in the service

Vietnamarea of a sewerage network is obliged to connect to it. The Vietnam Building Coderequires the installation of septic tanks for every household, resulting in on-site sanitation
technologies being connected to the drainage network. Periodic emptying of septic tanks
is also required. To ensure full access to sanitation, national and local governments needto prepare guidelines that cover various aspects of operation and maintenance, such as
the removal and transportation of sludge/septage other than plant installation.

15

Development of sustainable decentralized
domestic wastewater treatment technology
selection tools for ASEAN countries
Today there are a wide variety of decentralized systems for residential, industrial, and commercial use. Whenchoosing and installing such systems, several selection criteria need to be applied, including type of system,
wastewater characteristics and extent of treatment, human health considerations, level of management
and oversight required, and effluent standards to be met. In this project, we have prepared a guideline forthe selection of decentralized domestic wastewater technology to cater to the needs of local government
officials who are usually responsible for selecting the decentralized domestic wastewater technologies ininfrastructure development for sanitation. The following is an overview of the guidelines.
○ Decisions favoring a specific technical option in the early planning phase will strongly influence bothinvestment and operating costs. To provide cost-effective and sustainable decentralized wastewater
treatment, plants should take a holistic approach in selecting the treatment technology.
○ The selection of alternatives for new or upgraded decentralized wastewater treatment plants relies on
consideration of economic and non-economic criteria. However, the challenge of this approach tends to lie inthe difficulty of appropriate consideration for essential factors that are not readily quantifiable.
○ Economic criteria include parameters related to initial investment, operational, and maintenance costs.
Regarding non-economic criteria, technical criteria include parameters on land space requirements,
construction difficulty, operator technical skills, and ability to handle flow/quality variation. Environmental
criteria include parameters on nitrogen removal, BOD removal, and energy type. Social-related criteria include
air pollution.
○ During plan development, primary consideration is given by planners to the selection of treatment
technology. Several key factors are typically taken into consideration by planners in designing wastewater
treatment technology, such as land availability, capital, operational, and maintenance costs, and technicalskill requirement. Additionally, the primary criteria are also supported by other technical criteria that allow
16

planners to narrow down the technology options.

Regional policy recommendation
on domestic wastewater management
At the end of the project, based on the knowledge obtained and communication through dialogues andperiodic meetings among the stakeholders including Country Task Force team members, the following
regional “ONE vision” in each policy domain were agreed on.
1. Technological development for decentralized domestic wastewater treatment systems
Vision: Fulfill technological needs for decentralized domestic wastewater treatment systems for integrated
domestic wastewater management
2. Policy coordination on domestic wastewater management master plan
Vision: Reliable wastewater treatment system that is accessible to everyone
3. Potential financial mechanism and fee collection
Vision: Toward transparent, sustainable, and affordable financing mechanisms for decentralized domestic
wastewater system in ASEAN
4. Policy implementation and capacity building at the local government level
Vision: Ensure national-level policy implementation through multi-stakeholder involvement at national andlocal levels for safely managed domestic wastewater
5. Standardization of treatment performance testing method for decentralized domestic wastewater
management
Vision: Be accessible to reliable products of decentralized domestic wastewater treatment technology byharmonized testing protocols in ASEAN member states
17Future outlook
Based on knowledge gained through the PoDIWM project, we will continue to collaborate with each institution
aiming at the following six items.
1. COMMIT to continue dialogue through the framework of ASEAN Sectoral Bodies to enhance cooperation
on approaches toward improved domestic wastewater management in the region.
2. COMMIT to continue and initiate the policy interventions specified in this Regional Policy Roadmap in each
AMS
3. MAKE EFFORTS to achieve the goals and targets specified in ASCC 2025 and the Sustainable Development
Goals.
4. ENHANCE the regional knowledge-sharing mechanism on practices of AMSs in domestic wastewater
management through existing and potential platforms to accelerate the policy making on this agenda.
5. INVITE interested parties regardless of regional or non-regional bodies for support to reinforce domestic
wastewater management in the AMSs.
6. MAINTAIN the established network of professionals/experts who have worked together through the
project for knowledge/experience sharing.

18

Researcher’s comment
Access to safe water and sanitation is indispensable to maintain a minimum standard of living. There is no
exception to this principle, and no one should be left behind. In reality, unfortunately, many inhabitants in rural
areas, and even people in urban areas, still have limited access to safe water and sanitation in Southeast Asia.
The major source of water contamination in this region is domestic wastewater from households and commercial
buildings. Since the aquatic environment is harmed and sanitation conditions for inhabitants are deteriorating,
improving the situation whereby contaminated water flows into the environment is necessary to secure sanitationand hygiene.
A decentralized domestic wastewater management system is a sustainable and robust way of appropriately
managing aqueous environments in Southeast Asia. It can contribute to improving the water environment quality
when installed alone in individual residences or communities, and is expected to complement the centralized
sewage management system. Decentralized systems are also attracting attention as a way to provide vulnerable
populations access to safe water.
The aim of this project is to provide and share technical and institutional knowledge and to remove barriers to theadoption of decentralized systems in order to expand their applicability and feasibility in countries in the ASEAN
region. We hope that this report will further strengthen collaboration among the stakeholders in the region.

Tomonori Ishigaki, Dr.,
Material Cycles Division
National Institute for Environmental Studies, Japan
19

Contact
National Institute for Environmental Studies
Material Cycles DivisionInternational Waste Management Research Administration Officeintwaste_ra@nies.go.jp
Copyrights © 2020 All rights reserved
Published by National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba-city, Ibaraki 305-8506, JAPAN