The Biobrio 13(1 & 2), 2026

Investigation of the impact of opencast coal mining on the physico-chemical characteristics of water resources in Pakur District, Jharkhand

Pratima Kumari & Sutanu Lal Bondya

ABSTRACT:

This study investigates the impact of opencast coal mining on the physico-chemical characteristics of water resources in Pakur district, Jharkhand a tribal-dominated region adjacent to the Rajmahal coalfield, where no baseline water quality assessment has been previously documented. A total of 48 water samples (24 hand pumps, 12 ponds, 12 streams) were collected from two zones: Zone A (mining-affected, <5 km from mines) and Zone B (control, >20 km from mines), across two seasons (post-monsoon 2023, pre-monsoon 2024). Parameters analyzed included pH, TDS, sulphate, iron, manganese, heavy metals (Pb, Cd, Cr, Ni, Cu, Zn), DO, BOD, and COD following APHA standards. Statistical significance was tested using independent ttests. Groundwater in mining-affected areas showed severe acidification (pH 5.2 ± 0.4), elevated TDS (1210 ± 145 mg/L), sulphate (340 ± 38 mg/L), and iron (3.2 ± 0.6 mg/L) all exceeding BIS 10500 limits. Heavy metals including lead (0.028 ± 0.006 mg/L), cadmium (0.006 ± 0.002 mg/ L), and chromium (0.042 ± 0.008 mg/L) exceeded drinking water standards in Zone A groundwater. Surface streams exhibited the highest degradation with pH as low as 5.1, DO below 3 mg/L, and turbidity reaching 340 NTU. All parameters showed statistically significant differences (p<0.001) between mining-affected and control zones, with post-monsoon dilution reducing contaminant concentrations by 25-40%. Opencast coal mining has significantly degraded both groundwater and surface water quality in Pakur's mining-adjacent blocks. Immediate remediation measures including treatment of acid mine drainage, regular water quality monitoring, and alternative drinking water supply for affected villages are strongly recommended.

Keywords:    

Opencast coal mining, Acid mine drainage, Water quality, Heavy metals

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