Hydrogeochemical quality investigation of groundwater resource using multivariate statistical methods, water quality indices (WQIs), and health risk assessment in Korba Coalfield Region, India

Abstract

This study has attempted to investigate the effects of mining on groundwater quality in the Korba Coalfield region of Chhattisgarh, India. Hydrogeochemical processes and statistical methods have been used to assess groundwater quality. To achieve the objective, standard techniques and different indicators, including hydro-geochemistry, WQI, and multivariate studies, have been studied. The strong positive correlations were identified using the correlation coefficient between EC-TDS, EC-HCO3−, NO3−-Cl, and TDS-HCO3− respectively. The major cation abundance follows the order Na+ > Ca2+ > Mg2+ > K+, while the anion abundance is HCO3− > Cl− > SO42− > NO3− > F−. However, the hydro-geochemical facies in the area are predominantly of the Ca–Mg–HCO3 and Ca–Mg–Cl–SO4 types. Gibbs diagram indicates rock dominance have a significant impact on the concentration of both cations and anions. Furthermore, Hierarchical Cluster analysis reveals that 43 sampling locations were split into three clusters based on the WQI value, which represented the combination of geogenic and anthropogenic processes. As per Principal Component Analysis, PC1, PC2, and PC3 account for approximately 76% of the total variance, indicating determined variables that govern groundwater chemistry. The findings of the PCA indicate that both natural geological processes and human activities have an impact on the chemical composition of groundwater. As per WQI results, 33 (77%) samples were rated as excellent, 7 (16%) samples as good, and only 3 (7%) samples as having poor water quality, respectively. However, SAR and %Na analyses reveal that the majority of groundwater samples are classified as excellent to good for irrigation. The health risk assessment was conducted by determining the Hazard Quotient (HQ) using the intake exposure of groundwater according to the guidelines set by the United States Environmental Protection Agency (USEPA). Results indicated that some hazard quotient values exceeded 1 for both adults and children, resulting in non-carcinogenic risk. Overall, the groundwater in the vicinity of the Korba Coalfield is drinkable and suitable for irrigational applications after minor treatment. This research sets a benchmark for scientific studies conducted at both regional and global levels. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.