Evaluation of Heavy Metal Pollution Index and Water Quality Assessment in Coal Mining Areas: A Case Study of Jagannathpur Open Cast Mine, Chhattisgarh

This study assesses the impact of coal mining on surface and groundwater quality around the Jagannathpur open cast coal mine in Chhattisgarh, India, focusing on physico-chemical properties and heavy metal contamination. The research analyzed 8 primary water samples during the monsoon season and 6 secondary data points from pre- monsoon periods as reported by the Central Mine Planning and Design Institute (CMPDI) report, evaluating key parameters, like pH, total dissolved solids (TDS), dissolved oxygen (DO) and heavy metal concentrations (lead, manganese, copper, zinc, potassium, iron, arsenic, selenium, chromium and sodium). Techniques, such as atomic absorption spectroscopy (AAS), multi water quality checker and flame photometry were used. Results showed that surface water samples had a lower heavy metal pollution index (HMPI), ranging from 7.98-13.51, compared to groundwater, which had a higher HMPI ranging from 5.75-21.11, indicating moderate pollution. The surface water correlation matrix revealed a strong positive correlation (0.92) between pH and lead, while manganese (0.93) was strongly correlated with TDS and sodium (0.84) also showed a strong correlation. Potassium was positively correlated with TDS (0.66) and sodium (0.84). The groundwater correlation matrix indicated manganese was strongly correlated with iron (0.93), whereas arsenic and selenium displayed negative correlations with other metals. Sodium showed a positive correlation with chromium (0.46) and a moderate negative correlation with pH (-0.50). The analysis indicates that surface water is safe for irrigation, but manganese removal is necessary for safe domestic use. Groundwater, while unsuitable for direct domestic use, may be suitable for irrigation, although manganese levels exceed the acceptable limit (9.72 mg/L). The data also highlights seasonal variations in pollution levels, with a noticeable increase after monsoon season, suggesting that post-monsoon conditions may worsen the environmental impacts of open cast mine (OCM) activities. Continued monitoring and mitigation strategies are crucial to address these changes and reduce pollution in the region.