Summarizes two evaluations -- a final external evaluation (PD-ABD-903) and a sustainability assessment PN-ABN-080) -- of a project (1980-9/92) to assist the Government of Benin (GRB) in improving the health and living conditions of the rural population of the northern Zou department by increasing the availability and quality of the water supply and by improving local sanitation facilities and health practices. The major findings and conclusions were as follows. (1) The project achieved all of its quantitative targets, in several instances surpassing expectations: 500 villages health committees created, 109 ventilated improved pit (VIP) latrines constructed in primary schools, 261 family VIP latrines constructed, 309 positive wells equipped with hand pumps, and the annual incidence of Guinea worm decreased by more than 30% in the project zone. (2) The hand pump maintenance system is functioning well but its sustainability will require regular follow-up. (3) The use of a participatory and "cascading" training approach was well accepted by all project participants and contributed to project success. (4) Health messages were clear and understood by villagers to the extent that they could repeat and explain them; some were being put into practice. (5) Project benefits will be sustained if the rural economy grows and if all institutional structures in place function as expected. Additional assistance in the form of selected project activities will improve the probability that benefits are sustained. (6) The project, the first to implement the GRB policy of integrating water and health, will offer a valuable model for future interventions in the sector. (Author abstract)