Appraisal of groundwater quality for drinking and irrigation suitability using multivariate statistical approach in a...

The quantitative and qualitative stress on groundwater resources has been witnessed across the globe. The current study assesses the groundwater quality of Tirunelveli district which faces the hazard of groundwater contamination through seepage of toxins, considering the open dumping of huge volumes of solid waste. The findings from this study confirmed the presence of more than 20% samples in the "poor to very poor" quality with high concentrations of TDS, Cl^-, and NO₃^-, unfit for drinking, and other domestic purposes. The spatial distribution of TDS and NO₃^- highlighted the potential impact of solid waste dumping in the nearby landfill sites. K-means hierarchical clustering and multivariate analysis suggested that salinization and nitrate pollution was highly influenced by anthropogenic sources in comparison to geogenic sources. Rock water interaction and evaporation processes emerged as the two major dominant natural mechanisms controlling the groundwater chemistry. Four hydro-chemical facies were identified in the order of Ca-HCO₃ > Ca-Mg-Cl > Na-Cl > mixed Ca-Na-HCO₃. Thus, this study creates an urgent need of mitigation measures towards curbing and management of solid waste disposal and hence, the potential hazard of contaminant seepage into the groundwater.