Groundwater Contamination in India: Regional Variations, Hydrogeochemical Controls, Health Risks, and Integrated Management Strategies

Groundwater plays a critical role in meeting drinking and agricultural water demands in India. This review focuses on regional variations in groundwater quality, contamination sources, and remediation strategies. The evaluation encompasses pH, electrical conductivity, total dissolved solids, hardness, major ions, and contaminants including fluoride, arsenic, nitrate, and heavy metals. Results reveal significant regional variations, with contamination driven by intensive agriculture, industrial activities, mining, urbanization, and geological factors. Water Quality Index assessments indicate that while many groundwater sources meet drinking standards, numerous sites exceed permissible limits, requiring treatment. Contamination stems from both natural processes (mineral dissolution and rock–water interactions) and anthropogenic activities (fertilizer application, industrial effluents, domestic sewage, and mining operations). Health risk assessments demonstrate elevated noncarcinogenic risks in fluoride- and nitrate-affected areas, causing fluorosis, arsenicosis, methemoglobinemia, and other waterborne diseases. Various remediation approaches suitable for Indian conditions have been investigated, including membrane-based systems, electrochemical methods, adsorption techniques, and nature-based solutions. This review provides an integrated understanding of India’s regional groundwater quality challenges and emphasizes the necessity for targeted interventions, enhanced monitoring, and sustainable management strategies to protect groundwater resources. The review further provides an integrated regional comparison framework linking contamination sources, hydrogeochemical processes, health risks, and remediation strategies for groundwater management in India.