Ensuring Appropriateness of Biogas Sanitation Systems - Analysis from Rwanda, Nepal and the Philippines

Biogas sanitation systems are seen as a promising technology for institutional settings of developing countries as they combine effective treatment of human excreta and kitchen waste, while at the same time generating a renewable fuel source for cooking and a nutrient-rich fertilizer. The Water and Habitat Unit of the ICRC has been involved in the realization of biogas systems in prisons for the last 10 years to improve the poor sanitary conditions in detention facilities. In partnership with local organisations, ICRC has replaced the undersized and deteriorating septic tank systems in prisons of Rwanda, Nepal and the Philippines with fixed-dome biogas systems. After at least one year of operation, the 13 implemented systems were assessed in terms of their technical performance, economic viability, environmental impacts and social acceptance. For this purpose, on-site investigations were conducted (observations, interviews, measurement of gas production and composition, and analysis of process stability, reduction of organic load and pathogen content). 11 systems were in operation at the time of evaluation and displayed satisfactory process parameters with daily biogas production ranging between 26L/person and 62 L/person (obtained in prisons where kitchen waste was added to the digester). The vast majority of detainees perceived the biogas systems positively, mainly because it provides a smoke-free source of cooking fuel that contributes to money saving, and because it improved the hygienic conditions in and around the prison.

This paper synthesises the experiences from Rwanda, Nepal and the Philippines by grouping them into technical, operation & maintenance, economic, environmental and socio-cultural aspects. Based on these results, it highlights important issues such as criteria for site selection, dimensioning of digester, stakeholder’s responsibilities, and health risks and mitigation measures, which all need to be considered in order to ensure the appropriateness of biogas sanitation systems as sustainable solution for prisons in developing countries.