The Central Ground Water Board (CGWB) has reported that groundwater across India remains largely potable, with heavy metal contamination confined to isolated pockets. Routine monitoring covers basic parameters such as fluoride, nitrate and electrical conductivity, while trace metals including chromium, mercury and cadmium are tested based on specific requirements. According to the Annual Ground Water Quality Report 2025, CGWB collected 3,415 samples from 26 States and Union Territories for arsenic assessment during the 2024 pre- and post-monsoon seasons. Of these, 123 samples—3.6 per cent—exceeded the permissible limit of 10 ppb. A separate analysis of 2,537 samples from 21 States and UTs found that 24 samples—0.95 per cent—surpassed the permissible limit for lead at 0.01 mg/L. State-wise details are provided in two annexures. Under the National Aquifer Mapping and Management Programme (NAQUIM), aquifer studies incorporate quality assessments and recommended remedial measures, with findings shared with state agencies for further action. Responsibility for addressing contamination and providing safe drinking water rests primarily with state governments, though several central initiatives support mitigation. The Jal Jeevan Mission continues to prioritise contamination-free drinking water for rural households, guided by BIS:10500 quality standards. States receive a funding weightage for populations affected by chemical contaminants, and water quality monitoring protocols were formalised through a national framework issued in October 2021. More than 2,180 laboratories and trained village-level volunteers support routine testing through field kits, while community purification plants are advised for habitations facing persistent quality issues. CGWB disseminates groundwater quality data regularly through reports and alerts, and has introduced a revised Standard Operating Procedure to enable denser and more frequent sampling in sensitive areas. The Board has also developed a cement sealing technology to access deeper arsenic-free aquifers, constructing 525 safe exploratory wells across Bihar, West Bengal and Uttar Pradesh, and is supporting states to replicate the approach. Artificial recharge measures—implemented through initiatives such as Jal Shakti Abhiyan, Jal Sanchay Jan Bhagidari, Atal Bhujal Yojana, PMKSY and MGNREGS—help dilute contaminants in affected aquifers. Broader water quality improvements also rely on strengthening surface water systems through sewage treatment, effluent management and river conservation programmes under NMCG and NRCP. Pollution control efforts are overseen by the Central Pollution Control Board along with state agencies under the Water (Prevention & Control) Act, 1974 and the Environment (Protection) Act, 1986. Industry-specific effluent standards and compliance frameworks continue to guide enforcement to reduce pollution at source.