Current Project

Unsafe Return of Human Excreta to the Environment

sponsored by the Bill & Melinda Gates Foundation

The unsafe return of human excreta to the environment continues to be a significant challenge for most low- and middle-income countries. Hence, the importance of safely managing excreta along the sanitation service chain as a central focus of Sustainable Development Goal 6.2. Currently, an estimated 60-100% of people in low- and middle-income countries are relying on non-networked sanitation options, depending on the city and country. This results in excreta and wastewater discharging into a septic tank or pit, or into a drain, river, sea or the open ground.

Our research explores the flow of excreta from humans to the environment and the ‘hazard distribution’ at a community level. In addition, our research will be used to indicate the approximate reductions of hazard anticipated by alternative sanitation strategies, thus, assisting policy-makers in decision-making about sanitation technologies.

There is need to track human excreta beyond their initial deposit in toilets through to their final return to the environment, to ensure that the population is properly protected from the diseases spread by this waste. The Water Institute team, in collaboration with the University of Alabama and with funding from the Bill & Melinda Gates Foundation, will develop and pilot approaches for international agencies and countries to (1) estimate the fraction of human excreta unsafely returned to the environment, and (2) estimate where in the sanitation chain this occurs.

The work is intended to inform policy-makers, planners and service providers in efforts to reduce the public health threat of human excreta unsafely returned to the environment. The “global scorecard” for excreta management developed will assist governments, funding agencies and development agencies to address progress and the need for improvement more effectively, both from an improved understanding of the situation, and from the clearer insight into the global situation.

Water Institute Researchers
Report and Supplementary Materials: Models of Unsafe Return of Excreta in Four Countries

Report: Models of Unsafe Return of Excreta in Four Countries

Open Access Country Workbooks:

July 2019 Sénégal workbook

July 2019 Mozambique workbook

July 2019 Indonesia workbook

July 2019 Ghana workbook

Call for Feedback

We have conducted a review of peer-reviewed and grey literature to examine the unsafe return of human waste from pit latrines, septic tanks, and sewerage across the sanitation delivery chain. We invite WaSH professionals and practitioners to read and share feedback on the review, which can be accessed through our publications page.


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