Groundwater quality assessment for drinking and irrigation purposes and its human health risks in the Sevathur mine region, south India
V.N. Prapanchan, T. Subramani, D. Karunanidhi, P. Gopinathan
Abstract
In this research, 35 samples of groundwater were collected and subjected to analysis with the aim of assessing its appropriateness for both drinking and irrigation purposes in Sevathur mine region, south India. Spatial depiction illustrates the widespread dispersal of primary positively charged ions and negatively charged ions formulated through the Inverse Distance Weighting (IDW) technique within a Geographic Information System (GIS). The Piper and Gibbs plots reveal a variety of water compositions in the surveyed region, encompassing combinations of mixed Ca-Mg-Cl, Ca-Mg-Cl-SO 4 , Na-K-Cl-SO 4 , and a few instances falling within the category of Ca-Mg-HCO 3 . The current features of hydrogeochemical facies result from the interplay between geological formations and water, alongside the occurrence of ion exchange, dissolution and weathering of calcium carbonate, calc-silicate minerals, and halite within subterranean aquifers. The water quality index unveiled that 23% of the samples fall into the poor category, while a substantial 11% are categorized as very poor. Additionally, 3% are undesirable, 17% are unfit for drinking, 23% exhibit a good, and 23% are distinguished by excellent categories. SAR values of subsurface water samples belong to the excellent class. Additionally, the RSC value indicates that 94% of the samples are categorized as suitable class, while 6% are classified as marginal for irrigation purposes. Individuals are advised to avoid drinking groundwater with fluoride levels above the WHO limit (>1.5 mg/l), as 26% of samples exceeded this threshold. The region's groundwater chemistry is influenced by natural geological processes, such as mineral dissolution, and ion exchange, as well as human activities, including agricultural practices. Advanced water treatment techniques are being considered to improve water quality and ensure safer drinking water for the community. • Hydrogeochemical facies reveals major water types: Ca-Mg-Cl, Ca-Mg-Cl-SO 4 , Na-K-Cl-SO 4 , and Ca-Mg-HCO 3 . • Water quality index shows 23% good, 23% excellent, 23% poor, 11% very poor, 3% undesirable and 17% samples unfit for drinking. • Groundwater of Sevathur region is mostly suitable for irrigation-based RSC and SAR values. • Caution against high fluoride concentrations in groundwater for drinking for all age categories. • Water treatment and insitu groundwater recharge are recommended for potable water supply.