Sustainability of Lusaka sewage works

Lusaka, the capital city of Zambia, has a central waterborne sewerage system which was first constructed in 1956 and expanded upon in 1970 and 1980. It is currently serving more than 400,000 people which represents about 36% of the city’s population including trade effluents from industries. No major rehabilitation works have ever been carried out on this aging system over the past 15 years. In recent years, the system has experienced both operational and maintenance problems, ranging from poor management, untrained plant operators, lack of motivation among the workers and scarcity of funds. The key technical problems seriously affecting the works include: inoperative equipment such as influent flow meters, mechanical bar screens and grit chambers, reduced sewer and pump capacities, sediment build-up that block sewers and interfere with sewage pumps and frequent mechanical and electrical breakdowns. This paper highlights the main causes of these problems, the efforts that have been made to solve them and a mechanism that has been adopted in order to sustain the existing sewage works.