Africa, though reported to be the least urbanized continent, is recognized as one where the rate of urbanization is highest. The development and expansion of informal settlements in the suburbs of the cities is widespread, while they harbor the majority of the urban population. Slums are characterized by, among other things, poorly constructed houses, poor water supply and sanitary conditions, and lack or inadequate support services. Besides the spreading of diseases related to surface water (e.g., malaria), one of the main problems associated with sanitation and water in slum areas is related to the pollutant load entering and leaving the slum catchment, either as surface water or groundwater. This is polluting drinking water or causing eutrophication of surface water, due to the extremely high nitrogen and phosphorus fluxes discharging those slum catchments. The SCUSA research project aims at identifying the most sustainable sanitation solutions in urban slums, including the most important parameters determining and guaranteeing sustainability. Our approach is multidisciplinary, and should therefore yield answers with a financial, social, technical, and environmental view on the extremely complex field of sanitation in urban slums.