Assessment of Water Quality Around Surface Coal Mine in India

The present study highlights techniques to identify suitability of water for different purposes such as domestic, irrigation and industrial uses. Water samples from Olidih watershed in Jharia coalfield were collected in premonsoon (PRM) and post-monsoon (POM) seasons and analysed for different physico-chemical properties. Water Quality Index (WQI), Sodium Adsorption Ratio (SAR), percent sodium (%Na) and total hardness (TH) were determined on the basis of various physico-chemical parameters in order to ascertain the suitability of water for domestic, irrigation and industrial uses. The WQI for the study area found to vary from 23.86 to 166.72 in PRM season and from 22.14 to 146.44 in POM season. In 16.3% and 11.4% of watershed area, water is found unfit for drinking during PRM and POM seasons respectively. The calculated values of SAR and %Na indicate 'excellent to permissible use' of water for irrigation uses during both the seasons. High salinity, %Na and Mg-hazard values at some sites limit use for irrigation purposes. Box plots were plotted to represent seasonal concentration of the major ions which shows increasing trend of Ca, Na, NO₃ and SO₄ during POM.