Title : Hydrochemical characteristics of borehole water and its health risk in a drinking water basin in Ghana, West-Africa
Abstract:
Borehole water is an invaluable resource to all socio-economic activities. A drinking water basin underlain by the rocks of the Apollonian and the Birimian supergroup in Ghana, is characterized by rampant small-scale mining (legal and illegal). These activities have contributed to the deteriorating conditions of the basin making groundwater the only source of potable water. To assess the hydrochemistry and the health impact of drinking borehole water in the basin, fifty-five boreholes were drilled, pumping test was conducted, physiochemical, and microbiological analysis were carried out on each borehole and the results were analysed. The analysis of the results indicated that the aquifer hydraulic parameters (Transmissivity, Hydraulic conductivity and Specific Capacity) were higher in the aquifer of the Apollonian formation. Levels of trace elements (Fe, Al, Cd, As, Co, Cu, Fe, Mn, Pb etc) were higher in the aquifer of the Apollonian and the overall quality of the borehole water in the aquifer of the Apollonian and the Birimian were controlled mainly by rock weathering. The aquifer of the Apollonian formation yielded unsuitable water for drinking due to high pathogenic loadings and the aquifer of the Birimian supergroup yielded safe water for drinking due to low trace elements and pathogenic loadings.
Carcinogenic risk values of trace element in the borehole water were less than the maximum acceptable risk level. The outcome of this study has added to the current knowledge about borehole hydrogeochemistry and the health impact of drinking borehole water in Ghana and beyond.
