Assessment of surface water quality around opencast coal mines for sustainable utilization potentials: a case study in Jharkhand, India

Opencast coal mining has caused severe environmental degradation globally. In India, Jharkhand is infamous for the environmental damage already caused by unregulated coal mining practices so far. In the present investigation, surface water samples from 31 locations in Charhi and Kuju coal mining areas were analysed for physical and chemical parameters of water. Statistical analysis was performed to understand the magnitude of contamination and suitability of the water samples for agricultural as well as domestic uses. Analysis of variance indicated significant site-wise (6 out of 15 parameters) and seasonal variations (13 out of 15 parameters), while Pearson correlation indicated significant positive correlations between TDS-EC (r(2) = 0.74-0.99) and total hardness-HCO3- (r(2) = 0.95-0.98). Scatter plot between Ca, Mg and HCO3 revealed a positive interrelationship in all the three seasons. Surface water quality indices exhibited variable results of sustainable utilization potential of the water for various uses. Though water quality index advocated the quality of water to be good in the majority of the samples, health water quality index based on selected parameters hinted, the majority of the samples to be of poor category. Observations collated together suggest that though the area is in the initial phases of mining, contamination of the surface water bodies is increasing gradually and higher concentrations of metals (As, Fe, Mn, Se) are the most significant problem now. This study can serve as a baseline data and an early sentinel towards the increasing pollution and its effective environmental management in similar mining regions of the world.