Forms of unsewered sanitation are the most likely systems to be installed on low-income housing plots where sewerage is not practicable, due often to shortage of water and high cost. Updated advice is required on ways of evaluating the suitability of the ground to dispose of wastewater and latrine effluents. This note outlines the three main on- site sanitation systems, the problems of effluent disposal and possible groundwater pollution, and types of soakage system currently in use. Recommendations are made for site soil testing, application rates of effluent to soakaway infiltrative surfaces, and sizing of soakage systems.