Assessment of Physico-Chemical and Microbiological Parameters of Mthatha River in Eastern Cape, South Africa

Abstract

Mthatha River is the main source of water for the fast-growing population of Mthatha communities and its surrounding. Human resident settlements, livestock grazing and watering, subsistence farming and commercial activities are the main water and land use activities in the catchment. Using the environmental forensic method, this study was carried out to assess water quality in Mthatha River and its selected tributaries for different uses (drinking and domestic use) and identify potential pollution sources. Seven sampling points were purposively selected for water quality testing along Mthatha River and the tributaries. Data was collected during wet and dry seasons of the year 2021. Microbiological and physico-chemical parameters were measured in this study. Microbiological samples (i.e., Total coliform and E. coli) were analysed in the laboratory within 24 h. Physico-chemical parameters (Dissolved Oxygen, water temperature, pH, Electrical Conductivity, Turbidity, Total Dissolved Solids and Nitrate) were measured in-situ. Multivariate statistical analysis, one-way analysis of variance (ANOVA), and Pearson’s correlation analysis were employed to analyse the data using SPSS version 22, Primer version 7 and MS Excel 2013.The pH, turbidity and nitrate were found to be higher during wet season than dry season. Extremely high microbiological indicators (E. coli and total coliform counts) were recorded during both seasons and exceeding the WHO and DWAF permissible limits. The study also found that agricultural activities in the upper reaches of the river and a combination of refuse dumping and sewage pollution in the mid-stream section are the main causes of changes in the water quality of the Mthatha River and its tributaries. An assessment and monitoring of the river water quality is necessary for the Mthatha community and to communicate information on water quality for sustainable watershed management practices.