Dhakshinamoorthy R. and Selvarajan G.
Abstract
This study investigates the physicochemical and heavy metal characteristics of groundwater in the Mayiladuthurai District, Tamil Nadu, India. Ten samples collected from borewells and hand pumps were analyzed for key water quality parameters including pH (7.0-8.1), electrical conductivity (460-774 ?S/cm), total dissolved solids (226-547 mg/l), major cations, anions, and trace elements such as iron (Fe) and fluoride (Fâ). Several samples exceeded WHO and BIS permissible limits for TDS (30% of samples), total hardness (160-340 mg/l), sodium (11.8-288 mg/l), nitrate (up to 31 mg/l), iron (up to 1.0 mg/l in 40% of samples), and COD (up to 14.6 mg/l in 30% of samples). Correlation analysis revealed significant associations between EC and TDS (r = 0.95), TH and Na2+ (r =0.82), and NO3 â and COD (r= 0.71), indicating both geogenic and anthropogenic influences. The findings underscore the impact of agricultural runoff, domestic discharge, and local lithology on groundwater quality, and emphasize the need for regular monitoring and localized treatment interventions to ensure safe and sustainable water use.