Household-level application of hydrated lime for on-site treatment and agricultural use of latrine sludge

Rural areas of Cambodia have no safe waste management strategies for household latrine waste. Household application of lime (calcium hydroxide, Ca(OH)2) would enable households to treat waste easily on-site and significantly reduce the risk of latrine sludge causing negative impacts on human health and the environment, whilst transforming latrines into incubators of a valuable agricultural additive. Initial investigative work – including human centred design research, supply chain analysis and bench scale laboratory tests – have demonstrated that lime treatment of sludge has potential to provide a sustainable and effective solution to closing the sanitation loop in rural Cambodia, with promising application for urban environments as well.