Pit Latrine Additives: Laboratory and Field Trials

Pit latrines are on-site sanitation systems for accumulation and stabilization of faecal matter, urine and probably some other materials added to the system over a certain period of time. However, the process of anaerobic decomposition of materials in pit latrines is slow, resulting into build up of organic waste, odour production and fly nuisance which could pose significant risks to public health and the environment. There are various claims from suppliers and manufacturers that the use of bioadditives for the treatment of sludge content from pit latrines reduces the bulk of the sludge content in the pits. Field and laboratory trials were undertaken with two different bio-additives. In the field trials, the rate of accumulation was estimated from the distance between the pedestal and the surface of the pit contents while in the laboratory trials, the effect of the bio-additives on mass loss from pit latrine contents was investigated. In both cases, treatment with bioadditives was compared to treatment with water only, and to comparative experiments with no intervention. In both trials, the bio-additives had no beneficial effect on either the accumulation rate, or the rate of mass loss.