Abstract
M.Sc.
This study evaluates the correlation between rainfall and groundwater quality at the Impala Platinum Refineries site in Springs, 40 km East of Johannesburg, in Gauteng. The pollution of water resources including groundwater from mining operations is seen as significant. Due to historical mining operations and effluent treatment practices on the study site various pathways for pollution exists. Although the groundwater in the area is not used for irrigation or domestic use the deterioration in the vicinity of the East Geduld No.1 tailings dam is concerning in light of the close proximity to the Blesbok Spruit RAMSAR wetland.
In order to assess the extent of water pollution attributed by historical land use and effluent treatment practices, as well as the relationship between rainfall and groundwater quality, two series of analyses have been employed. The chemical analyses determined whether the water quality is within the Target Water Quality Range (TWQR) as prescribed by the Department of Water Affairs for domestic use. The statistical Pearson Correlation analyses were used to determine the relationship between rainfall and water quality which assisted with interpreting whether concentrations increase due to percolation from the soil or decrease due to dilution.
The study proved that there exists no high degree of association between rainfall and groundwater quality in the study area. However it was established that certain metals reacted differently under varying pH, sulphate and chloride concentrations. The ground water in deeper boreholes will therefore take significantly longer to wash out the pollutants due to the low effect rainfall has on diluting the water. Soil disturbance in the area also played a role in mobilising the metallic pollutants. The presence of a pollution plume emanating from the tailings dam was identified in 1995 and the water quality deteriorated significantly in the area as from 2004.