Groundwater Geochemical Investigation and Quality Assessment for Drinking and Irrigation Uses in Sohagpur Coalfield, Madhya Pradesh, India

The present investigation aims to assess the processes controlling the composition of groundwater in the Sohagpur coalfield and its quality concerning drinking and irrigation purposes using hydrogeochemical and statistical approaches, water quality indices, and a geographic information system (GIS). Twenty-seven groundwater samples collected from different sites were analysed for electrical conductivity (EC), pH, turbidity, major anions and cations, total dissolved solids (TDS), and total hardness (TH). The study results show that the pH of samples varied from 5.97 to 8.26, suggesting the acidic to slightly alkaline nature of the water samples. The TDS ranged from 265 to 1450 mg/L with 78% of the samples being in the freshwater category. The Ca2+-Mg2+-SO42- and Ca2+-Mg2+-HCO3- are dominant hydrogeochemical facies in the Sohagpur coalfield. The hydrogeochemical and statistical methods show that the groundwater chemistry of the Sohagpur coalfield is primarily controlled by the dissolution and weathering of minerals and secondarily due to the influence of anthropogenic activities (i.e., agricultural practices, sewage, and animal waste discharge). In the majority of the groundwater samples, concentrations of TH, TDS, turbidity, and SO42- exceeded the Bureau of Indian Standards (BIS) drinking acceptable limits and suggested that water is unsuitable for direct consumption. Moreover, the estimated water quality index (WQI) indicated that 52% of the samples (especially from the Dhanpuri and Amlai areas) belong to poor to unfit water categories. High values of EC in 56% of the samples and magnesium hazard (MH) at two sites restrict the irrigation suitability at these locations.