A proposal for managing wastewater in Harare, Zimbabwe

This paper deals with wastewater management in Harare, in the Lake Chivero catchment area of Zimbabwe. It aims at developing a sustainable system for managing water and nutrients and is based on the literature and a water quality monitoring Study conducted from June 2000 to December 2001. This study has shown serious water pollution problems due to urbanisation in the catchment. A 1 three-step strategic approach' 10 urban (waste)water management was used as a basis for formulating solutions. The short-term Solutions include reduction of wastewater volume in industries and households, reducing wastewater flows by 24% and total phosphorus by 5%. The medium-term solutions involve treating wastewater to high standards, resource recovery and reuse, and controlling upstream sources of pollution, and thus would reduce the lake total nitrogen and total phosphorus levels to about 0.4 and 0.07 mg/L, respectively. A long-term solution was suggested based on pollution prevention and direct reuse, treatment at onsite and decentralised levels followed by reuse, and minimal disposal of the remaining effluents combined with the stimulation of the self-purification capacity of the receiving rivers. it was concluded that it is feasible to reduce pollution levels in the catchment by applying these phased developments.