Sanitation: planning the transition to waterborne systems

The proportion of people with access to improved sanitation in sub-Saharan Africa is just over 30%. In this context, the Lake Victoria Water and Sanitation Initiative in Africa is aimed at helping secondary towns in the Lake Victoria region meet the water- and sanitation-related millennium development goals. Particular emphasis was placed on the sanitation sector, with consideration given to improved on-site sanitation as well as sewerage schemes for the urban core. Planning the transition from on-site sanitation systems to sewerage is not straightforward. If sewerage is implemented too early, there may be insufficient uptake of the services, jeopardising the technical and commercial viability of the scheme. Similarly, if interventions are left too late, urban areas will struggle to dispose of the wastewater in a safe and hygienic manner. This paper discusses the key technical factors that should be taken into account when planning such a transition and presents some of the tentative guidelines developed as part of the initiative's phase II project. It is hoped that this paper will raise awareness of the subject and that the tentative guidelines described here will be of some practical use to future decision-makers.