An investigation into the effect of various levels of sanitation on surface

Abstract

A growing need exists to assess the impact of urban and industrial development on the aquatic environment. Environmental strategies, which will result in an improvement of environmental quality without excessive cost, must be designed and implemented. In order to do this, it is important to identify sources of pollution, to quantify the possible pollutant load, and to identify such pollutants' pathways into the aquatic environment. The primary objective of this study was to investigate the effect of various levels of sanitation on the quality of urban storm water run-off. The Klein Modder River catchment, in the province of the Free State, South Africa, was selected as site for this study. Botshabelo is a large settlement in the catchment of the Klein Modder River. The city contains various types of developing urban profiles similar to those found elsewhere in developing urban areas in South Africa. The city has substantial shortcomings in sanitation that could lead to pollution of stormwater run-off. The pollution impact of three sub-catchments of Botshabelo, w here different levels of sanitation are being used , was investigated. The typical sanitation systems were waterborne sewage, bucket latrines and pit latrines. The pollution impact was evaluated by means of measured microbiological indicators, w hich are generally used to define the safety of surface water bodies for human contact. The flood peaks in each catchment were also calculated, and it was established that the hydrological variance, as a factor influencing the variability of the results, could be neglected. The conclusion reached was that the extent of pollution is clearly determined by the level of sanitation systems and the quality of the management of these systems .