Evaluation of Spatial and Seasonal Variations in Groundwater Quality at Kolar Gold Fields, India

Underground gold mining at Kolar Gold Fields (KGF), Karnataka, was carried out for more than a century, which disturbed the groundwater aquifers. In addition, leaching from mill tailings dumps has also been contaminating groundwater in this area. The aim of the study was to assess the groundwater quality and its suitability for drinking purpose. A detailed survey was carried out within a 10 km radius of KGF and 12 borewells, being used for domestic purposes, were identified for groundwater sampling. The samples were collected from each borewell in each season and analysed for different water quality parameters. It was found that pH, total suspended solids, nitrate, arsenic, fluoride, cyanide, sulphate, alkalinity and sodium in groundwater were within the regulatory limits whereas other parameters exceeded the norms. Water quality index (WQI) was evaluated to know the overall quality of groundwater for each borewell for different seasons. Multiple regression model was developed for prediction of WQI and the performance of the model was assessed. Methods for the treatment of groundwater have also been suggested in this paper.