Spatial and temporal variations of dug well water quality in Korba basin, Chhattisgarh, India: Insights into hydrogeological characteristics

Comprehensive assessment of groundwater quality in mining-affected regions is crucial to sustainably manage water resources and protect public health and ecosystems. This study investigated the hydrogeochemical characteristics and water quality of 18 dug wells in the Korba basin, Chhattisgarh, India, an area heavily impacted by coal mining activities. Water samples were collected over three seasons (pre-monsoon, monsoon, and post-monsoon) and analyzed to determine physicochemical parameters, major ions, trace elements, and carbon content. Results revealed very high total dissolved solids concentrations ranging from 315 to 19,738 mg L−1. Nitrate levels surpassed the Bureau of Indian Standard (BIS) limit of 45 mg L−1 in over 50% of samples, reaching a maximum of 200 mg L−1. Fluoride concentrations in all samples exceeded the BIS limit (1.5 mg L−1), ranging from 1.5 to 15.2 mg L−1. The predominant water type was Ca-Mg-HCO₃, primarily influenced by rock-water interactions. Factor analysis indicated that both geogenic and anthropogenic processes influence pollution levels. Pollutant concentrations exhibited seasonal variations, generally peaking during the monsoon period. Temporal analysis from over six years revealed increasing trends for most parameters, indicating deteriorating water quality. Based on Water Quality Index values, all samples were classified as unsuitable for drinking, while assessments of irrigation water quality using various indices indicated that 61.11% of samples were suitable for agricultural use. The findings provide data to inform decision-making and public health protection in this heavily industrialized region and emphasize the urgent need for sustainable water resource management and pollution prevention strategies in the Korba basin to align with UN Sustainable Development Goals 3 (good health and well-being) and 6 (clean water and sanitation). [Display omitted] •Hydrogeochemical characteristics of water from dug wells in Korba basin were presented.•Nitrate and fluoride contamination in dug well water of the basin were detected.•Water of the Korba is mainly Ca-Mg-HCO3 type, influenced by rocks and water interaction.•Both geogenic and anthropogenic sources are responsible for dug wells pollution in the basin.•Water quality evaluation data showed that most waters were suitable for irrigation.