Analysis of faecal sludge collection efficiency for improvement in developing countries

In most developing countries on-site sanitation, and more specifically septic tanks, will remain the primary sanitation system used for human waste management for many years to come, as the cost of installing sewerage infrastructure remains prohibitive. However, studies have shown that septic tanks are rarely desludged, which reduces their wastewater treatment performance and greatly increases the risk of tanks becoming pollution sources. Furthermore, the systems in place for faecal sludge collection often lack efficiency and the existing services tend to be outside of public sector control and not regulated. To ameliorate this situation, the development of new analysis methods for faecal sludge collection systems is crucial. This paper presents an analysis method adapted from “time and motion studies” in solid waste management and a mathematical model which allows for precise analysis of faecal sludge collection and recommendations to be made to dramatically improve the efficiency of existing collection systems