- Posted on 16 Apr 2026
- 3-min read
New research helps Indonesia’s government understand sanitation sector emissions towards reducing emissions and improving public health.
Researchers at the UTS Institute for Sustainable Futures (ISF) have published the results of a first-of-its-kind project that investigated greenhouse gas emissions released from diverse wastewater systems in Indonesia.
The Emissions Measurement to Improve Sanitation in Indonesia (EMISI) project was an initiative of the Ministry of Public Works of the Government of Indonesia, supported by DFAT through KIAT, the Indonesia Australia Infrastructure Partnership. EMISI was delivered by a team of sanitation experts from ISF, Universitas Indonesia (UI), Centre for Regulation, Policy and Governance (CRPG), University of Leeds and the University of New South Wales.
Why sanitation?
Wastewater is the world’s fifth largest source of methane and the third largest source of nitrous oxide. These gases affect global warming at a higher rate than carbon dioxide.
Emissions arise at each step of the sanitation chain, from the toilet to final disposal of treated wastewater and faecal sludge into the environment, as well as points where untreated liquid or sludge enters the environment.
Indonesia has committed to reducing emissions under the Paris Agreement and the country’s Nationally Determined Contributions (NDCs) identify the wastewater and sanitation sectors as areas where reductions can be made.
Why EMISI was different
Until EMISI, most studies of sanitation-related emissions have focused on centralised, sewered wastewater systems in high-income countries. Sanitation in Indonesia works differently, with most people (over 86%) utilising household-level containments (variations on septic tanks) that must be regularly emptied but in practice are often not.
Previous studies have had a narrower focus, tallying emissions for specific systems at city-level. EMISI is the first national study of emissions from sanitation for a low- or middle-income country.
EMISI broke new ground in measuring emissions from sanitation systems never directly measured before.
Partnering for success
ISF led the project, coordinating the 30+-person team across three countries under the leadership of Prof Juliet Willetts and Dr Cindy Priadi, from Universitas Indonesia and an adjunct to ISF.
Working closely with Indonesian partners was key to EMISI’s success. Project Manager and ISF researcher Leanne Casey says, “…it really promoted local ownership of the results, and improved [the Indonesian government’s] capacity as well. We really hope that the relationships built along the way will be long term relationships extending beyond the project.”
How the research will be used
The Government of Indonesia was involved in EMISI from the beginning, building their capability to evaluate and use the data in the future. The data equips the Government with evidence towards reducing emissions and later, accessing climate finance.
The EMISI project provided practical and policy recommendations for Indonesia to improve the country’s sanitation and reduce emissions including:
- Prioritise safely managed sanitation
In Indonesia, basic toilet access is high but only around 1 in 10 people use sanitation that safely manages waste all the way from toilet to treatment. EMISI recommends first protecting public health by increasing safely managed sanitation systems. This will also allow emissions to be contained and reduced with methane capture technology. - Link sanitation policy with climate policy
Set clear national targets for reducing emissions from sanitation, improve accuracy of sanitation estimates in greenhouse gas inventory, clarify who is responsible, and include emissions considerations in sanitation rules, standards and planning decisions. - Improve sanitation infrastructure and management
Replace poorly built household toilets to meet national standards,. Increase regular desludging and stop sludge being dumped into the environment. Monitor and optimise treatment processes in communal and larger systems, fix breakdowns and capture methane where feasible. - Build skills, data systems and access to climate finance
Train engineers, operators and officials to measure and manage emissions, create an agreed system for tracking sanitation-related emissions, and use this data to unlock climate finance.
Find out more
Find out more about the EMISI project and view project outputs