The effects of human activities on water quality of the Bottelary River, Cape Town, South Africa

Abstract

Freshwater scarcity and river pollution has become a serious challenge for governments and scientists. Worldwide, governments have a responsibility to provide their populations with clean water for their domestic needs. Scientists have an enormous task to find a way to purify polluted water, because of its vital role in human lives and an increasing demand for water consumption due to population growth. Although the water from the Bottelary River is used on a daily basis for farming activities, its pollution level as well as spatial distribution of effluents in the catchment is unknown. In the present study, monthly water samples from six sampling points were taken for laboratory analysis. The laboratory determined concentrations of phosphorous, chloride, nitrate, and nitrate nitrogen (NO3-N), as well as the chemical oxygen demand (COD) and suspended solids. While, pH, dissolved oxygen, electrical conductivity and temperature were measured in-situ using a multi-parameter reader. The results were then compared with the South African Water Quality Guidelines for Aquatic Ecosystems and for irrigation (DWAF, 1996a,1996c). The findings of the study revealed that the concentration levels of some compounds are below the Target Water Quality Range (TWQR) set by the Department of Water Affairs and Forestry (DWAF, 1996a, 1996b, 1996c) while, the concentrations of chloride, total nitrogen and water quality variables such as electrical conductivity, suspended solids, are higher than the TWQR (DWAF, 1996a, 1996b, 1996c). Based on the above findings water of the Bottelary River can have negative effects on the environment and human lives because of the level of these compounds. It was therefore recommended that environmentally friendly measures and practices must be undertaken in order to decrease the pollution and avoid further pollution of the river.