Hydrogeo-chemical characteristics of groundwater and seasonal variation in coal mining area, Madhya Pradesh , India

Abstract

Abstract In the present study, total 50 groundwater samples were collected during pre-monsoon, monsoon and post-monsoon around Sohagpur coal fields in Shahdol district, Madhya Pradesh. The study includes graphical plot, water quality indices and multivariate analysis of the hydrogeo-chemical data to identify major process that control the groundwater chemistry. The analytical results shows that pH of the groundwater samples have slightly acidic to alkaline in nature with dominance of Ca2+ and Mg2+ ions. The water chemistry of the groundwater is mainly controlled by carbonate and silicate weathering with small contributions from anthropogenic source. Piper trilinear diagram showed Ca-Mg-Cl-SO4 and Ca-Mg-HCO3 dominant water type throughout the seasons. Comparison of analyzed parameters with World Health Organisation (WHO) and Bureau of Indian Standards (BIS) for drinking water shows that EC, TDS, Cl-, and HCO3- in most of the groundwater samples exceeding the permissible limits and not suitable for drinking purpose. Drinking water quality index (DWQI) shows that most of the samples are in excellent and good condition with few exceptions in pre-monsoon and monsoon seasons. The magnesium hazard (MH) values are found to be high at several locations which make it unsuitable for irrigation. Principal component analysis (PCA) and cluster analysis indicate that carbonate weathering is the dominant process in all three seasons and has effect of dissolution of sulphate and chloride minerals in groundwater. The overall study shows that there is influence of coal mining activity in groundwater quality and regular monitoring will be helpful to decision maker for better management of groundwater for future perspective.