Hydrochemistry and quality assessment of mine water of west boakro coalfield
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A total of 33 samples of mine water discharges from the different mines of West Bokaro Coalfields of Hazaribag district of Jharkhand, India, were analyzed to carry out qualitative assessment and suitability for domestic, irrigation and industrial purposes. The electrical conductivity (EC) for measured samples and spatial differences reflects the wide variation in lithology, surface activities and hydrological regime prevailing in the region. The anion chemistry shows the dominance of SO4 2- and HCO3 - with minor contribution from Cl, NO3 and F. The cation chemistry indicate that 79% of the samples are Ca > Mg > Na > K, while the 6% belong to Ca > Na > Mg > K and 1% of Ca > Mg > K > Na. Concentrations of some heavy metals (Fe, Mn, Ni, Cr) are found to be well above the prescribed permissible levels recommended for the drinking water. The water quality assessment for drinking purposes indicate that most of the mine water having high TDS, total hardness (TH) and sulphate concentrations, suggests that mine water of the study area is not suitable for direct use in drinking and domestic purposes. The mine water can be used for irrigation purposes; however, high values of salinity, %Na, SAR, RSC and Mg-hazard at certain sites restrict its suitability for agriculture uses. Key words: Mine water, ion chemistry, quality assessment, West Bokaro coalfields. 1. Introduction All opencast as well as underground mining invariably changes the hydraulic gradient, thus affecting ground and surface water flow regimes vis-à-vis their quality and quantity. The presence of water in mining sites create a range of operational and stability problems and requires drainage to avoid slope stability problems and action to minimize oxidation of metallic sulfides and corrosion of mining machinery and equipment. The quality of the mine water depends on a series of geological, hydrological and mining conditions, which vary significantly from mine to mine [1]. Mining by its nature consumes as well as diverts water and can also pollute water resources of Corresponding author: