Tiger worm toilets: lessons learned from constructing household vermicomposting toilets in Liberia

In response to the poor urban sanitation in Monrovia’s slums and Buchanan’s peri-urban areas in Liberia, Oxfam piloted worm toilets (aka Tiger Toilets), constructing 180 toilets between 2011 and 2015. One toilet was constructed per household for families containing fewer than 10 people. Each toilet was connected to a biodigester containing 2 kg of African night crawlers (Eudrilus eugeniae). This paper documents the programme approach including how the community was mobilized and the construction process. The results section reviews field observations, challenges, and the maintenance problems encountered. In the discussion the paper reviews the design changes, lessons learned, limits for scale, and critical factors for success (favourable environment, local supply, infiltration capacity, and local technicians). The paper concludes that although the project is still ongoing, the study suggests that the African night crawlers can digest significant volumes of human excreta if proper conditions of aeration, m...