Experiences with dry sanitation and greywater treatment in the ecovillage Toarp, Sweden

Experiences with dry sanitation and greywater treatment in the ecovillage Toarp, Sweden, are described, based on field studies and a survey. Technical, environmental and social issues were evaluated. The greywater was treated effectively concerning BOD₇, COD, Tot-N, Tot-P and thermostable coliforms. Dry sanitation was implemented in order to recycle human excrements locally, but people's request for an environmentally sound way of life was confronted with major technical and operational problems. Composting toilets were implemented without sufficient knowledge and usage directions, resulting in partly disastrous operational results. In consequence, the majority of the ecovillage's composting toilets are now replaced by water toilets. The experiences in Toarp indicate a high demand in research activities concerning dry sanitation. Necessary research and development are described. Depending on the results, dry toilet systems might not only stay a sanitary solution in widespread areas but become a future tool to recycle human excrements.