The cost benefit and efficiency of waste water treatment using domestic ponds—the ultimate solution in Southern Africa

Abstract

Wastewater treatment has become a challenge to most countries in Southern Africa because of the fluctuating economies that have been hit by high levels of debts. The treatment of domestic wastewater using ponds, if carefully utilized, as has been observed in most countries in the world, is the most cost effective means of handling wastewaters. When compared to the conventional use of treatment plants, the ponds have been observed to be the ultimate solution for the countries in Southern Africa especially those that are classified as Highly Indebted Poor Countries (HIPC) because of little or no operating costs associated with the treatment. The study conducted on Kitwe Waste Water Treatment Ponds to evaluate the cost benefit and efficiencies has revealed low levels of operating cost and high removal efficiencies of oxygen demanding wastes (BOD removal of 86% and TSS removal of 75%), pH values ranged from 7 to 8 indicating an increasing alkalinity from facultative to maturation ponds while other parameters such as nitrates, phosphates and temperature were found to be within acceptable levels thereby releasing effluent that makes the environment sustainable. The overall social benefit was found to be much higher than the operating costs.