Water Quality Assessment and Correlation Study of Physico-Chemical Parameters of Sukinda Chromite Mining Area, Odisha, India

The Sukinda Chromite Valley of Odisha state is endowed with the highest reserve of chromite ore in India and produces 98% of the chromite ore of the country. Cr (VI) is a highly toxic form of chromium metal being used in different industries like leather tanning, electroplating, dye and pigment. Due to open cast mining process in Sukinda chromite valley, huge quantity of over burden dump (OB) are being generated and during rainy season Cr (VI) leached from the OB dump and contaminate the ground water as well as surface water of the surrounding area. Different water samples were collected from mines, surface water and groundwater and analyzed for their physico-chemical properties including heavy metals and Cr (VI). The result shows that at some locations, the total Cr and Cr (VI) concentration exceeded the permissible limit of 0.05 mg/L as per Indian water quality standards, despite mine water treatment at mine sites. The concentration of total Cr in mine water ranged from 0.32 to 1.46 mg/L before treatment and between 0.02 and 0.42 mg/L after treatment. Total chromium for surface water varied from 0.04 to 0.38 mg/L and for groundwater varied from 0.001 to 0.678 mg/L which exceeds the permissible limit of 0.1 mg/L for inland surface water. Cr (VI) content in these water samples also exceeds the permissible limit of 0.05 mg/L. Pearson’s correlation analysis revealed that the Cr exhibited a significant positive correlation with pH (0.688), temperature (0.428), Total hardness (0.568) and sulphate (0.686). Cr (VI) also showed the similar results with total chromium.