Geochemical assessment of basaltic groundwater contamination in an industrial area: A case study of Ranjangaon MIDC, Maharashtra

Industrial activities have exacerbated environmental challenges, especially in water-scarce regions where groundwater is a critical resource. This study presents a detailed geochemical evaluation of groundwater in the Ranjangaon MIDC region, Maharashtra, highlighting seasonal and spatial variations in water quality between summer and winter. Groundwater extraction is most intense in the middle reaches, with a clear trend of increasing mineralization from upstream to downstream. While pH values (6.5–8.5) and total dissolved solids (<2000 ppm) comply with WHO standards, elevated salinity and electrical conductivity in several wells raise concerns for water safety and agricultural productivity. Gibbs plots initially suggest evaporation and precipitation dominance in groundwater chemistry, but industrial sources are confirmed for SO₄²⁻ and Cl⁻ based on scatter plot analyses. Piper diagrams reveal consistent water types dominated by Ca²⁺ + Mg²⁺ > Na⁺ + K⁺ and Cl⁻ + SO₄²⁻ + NO₃⁻ > HCO₃⁻ + CO₃²⁻, with minimal seasonal variation. Elevated SO₄²⁻ and Cl⁻ levels, coupled with volatile organic compounds (VOCs) from industrial wastewater, suggest significant contamination. Spatio-temporal analysis indicates that industrial discharge significantly degrades water quality, as evidenced by elevated WQI across all water sources. Prolonged consumption of highly alkaline water poses potential health risks, including metabolic alkalosis, which can cause confusion, nausea, and muscle twitching. This study highlights the critical need for vigilant groundwater management and targeted mitigation strategies to address contamination and safeguard public health in this rapidly industrializing region. Despite general compliance with regulatory standards, the findings highlight salinity, conductivity, and industrial contaminants as key concerns threatening the sustainability of this vital resource. • Seasonal shifts in groundwater with marked salinity and conductivity changes. • Downstream shows rising mineralization with high sodium and chloride levels. • High alkalinity in some areas raises health concerns like metabolic alkalosis. • Strong need for careful groundwater management to sustain industrial regions.