A geophysical and hydro physico-chemical study of the contaminant impact of a solid waste landfill (swl) in King Williams' Town, Eastern Cape, South Africa

Abstract

Electrical resistivity imaging (ERI) surveys and physico-chemical analysis were carried out on a solid waste landfill (SWL) in Eastern Cape, South Africa to assess the impact of leachate pollution on groundwater quality. 2-D resistivity imaging was done across three profile lines (A, C and E) on the landfill. Physico-chemical properties of water samples from the leachate pond and boreholes (BH1 and BH2), located between 80 m to 200 m from the edge of the landfill were analysed. The results revealed groundwater contamination to a depth of about 75 m,well within the aquiferous zone. High electrical conductivity (EC) and total dissolve solid (TDS) values observed in the groundwater samples indicate a downward transfer of leachate into the groundwater. The difference in EC and TDS values for BH2 and BH1 (9892 μS/cm/ 4939 mg/L and 6988 μS/cm/ 3497 mg/L respectively), indicated that concentration of contaminants increased towards the centre of the landfill The direction of flow of the leachate is towards the southwestern part of the landfill. In the absence of a leachate recovery system, the uncontrolled accumulation of leachate over time at the landfill will pose a threat to the groundwater quality, hence the need to improve waste management practices in the study area to mitigate the effects of pollution.