Hydrogeochemical assessment of groundwater quality in the Soutpansberg Basin around Tshikondeni, Limpopo Province, South Africa

Abstract

The objective of this study was to investigate the impact of anthropogenic and natural sources of contamination on the groundwater quality of the unconfined aquifer system of the Soutpansberg Basin around Tshikondeni. Fifteen groundwater samples were collected and analysed for physical and chemical parameters. Groundwater samples were analysed for pH, EC, TDS, major cations (Na + , Ca +2 , K + , and Mg +2 ), major anions (Cl − , SO 4 −2 , NO 3− , CO 3− and HCO 3− ). Groundwater in this area was found to be above the desirable Department of Water and Sanitation (DWS) and World Health Organisation (WHO) limits for domestic and irrigation purposes. After the physicochemical analysis of groundwater, samples shows that, the type of water that predominates in the study area is Na + -K + -Ca +2 -Mg +2 type during the summer of the year 2008, based on hydro-chemical facies. Interpretation of hydro-geochemical data suggests that leaching of ions followed by weathering and anthropogenic impact (mainly mining and agricultural activities) control the chemistry of groundwater in the study area. Groundwater suitability for drinking purpose was also evaluated by the synthetic pollution index (SPI), it suggested that most of the samples fall in seriously polluted categories. The calculated values of SAR, Na%, RSC, PI, and MH have shown that except at few locations, most of groundwater samples are not suitable for agricultural and domestic purposes.