Hydrogeochemical and Anthropogenic Controls on Groundwater Quality in the Talensi District, Northern Ghana: Implications for Arsenic Contamination

Talensi District is mainly a rural area in the Upper East Region of Ghana, which relies heavily on groundwater for drinking and irrigation purposes. However, there are several artisanal and small-scale mining (ASM) activities in the district, which pose a serious threat to groundwater quality in the area. Therefore, the current study assessed the hydrogeochemical and anthropogenic controls that influence the quality of the available groundwater sources in the areas dominated by ASM activities in the Talensi District. The study utilized hydrogeochemistry, chemometric analysis, and geographic information system to assess the sources of the groundwater constituents. A total of ten (10) groundwater samples were collected from the ASM-dominated areas in the Talensi District. The aquifer is dominated by Na-SO4-HCO3 and Na-SO4 hydrogeochemical facies. These water types are derived from water-rock interaction, forward ion exchange reaction, and dissolution of rocks containing gypsum, halite, calcite, and aragonite. The mean concentrations of the potentially toxic elements (PTEs) vary in the order Fe > Pb > As > Mo > Cr > Ni > Cd > Sb > Cu. All the samples showed concentrations above the guideline values set by the World Health Organization for Fe, Pb, As, Mo, Cr, and Ni. The As concentrations in the groundwater samples are in the range of 2.90 to 6.5 mg/L with a mean concentration of 4.5 mg/L. The weathering and dissolution of ore minerals and leaching of chemicals used in processing gold in the area during the ASM activities are the causes of arsenic enrichment and mobilization in the groundwater.