Developing an Infrastructure Intervention for Solid Waste Exclusion in Pit Latrine Faecal Sludge

Abstract

Pit latrine emptying is an important maintenance practice meant to increase a toilet's lifespan. However, the presence of solid waste in faecal sludge pose a great challenge during pit emptying, faecal sludge treatment and processing. Recent studies have demonstrated that solid wastes cause pits to fill up at a faster rate, destruct faecal sludge decomposition, and cause damage to emptying devices by blocking machine parts, and in some cases breaking them. When such occurs, emptying devices are usually withdrawn to manually remove the trapped debris, causing a loss of valuable time and reductions in daily revenue. One way of averting the adverse effects of solid wastes in pit latrines is by preventing them from mixing with faecal sludge in the pit. Therefore, the study aimed to design, develop and test an infrastructure intervention that would exclude solid waste from pit latrine faecal sludge. The study used a quantitative approach in which experimental methods were used to collect primary data. The methodology included the design, fabrication, and installation of a solid waste screening unit on a pit latrine. The screening unit was positioned directly below the squat hole to intercept solid waste while allowing excreta to pass through it. The unit was tested on a pit latrine that was used by 20 individuals over a period of 120 days, after which mass measurements of the intercepted solid wastes were done. The data obtained was analysed using Microsoft Excel 2016 version. It was found that the screening unit was capable of intercepting 88.2±0.6 % of the solid waste that entered the toilet through the squat hole. This confirmed that although behavioral, and education interventions have been conducted, there was little change in behavior towards the dumping of solid wastes in pit latrines. The study also showed that installing solid waste screening systems in future pit latrines can be one way of preventing solid wastes from mixing with pit latrine faecal sludge. These findings suggest that incorporating solid waste screening systems into future pit latrines could effectively prevent solid waste from mixing with faecal sludge. This intervention promises to complement existing behavioral and educational interventions prevalent in many developing countries. The study's application and findings promise improvements in faecal sludge management during pit emptying, treatment, and processing, thereby enhancing public health outcomes.