Groundwater is crucial for India’s water supply and it is the largest user of groundwater across the globe, extracting about 230 cubic kilometers each year, which is more than a quarter of the world’s total.
More than 60 per cent of irrigated farming and 85 per cent of drinking water is derived from groundwater reserves.
Urban areas increasingly depend on it because municipal water supplies are often unreliable. However, groundwater quality is declining due to natural and human activities, which threatens public health, agriculture and sustainability.
The Annual Groundwater Quality Report released on December 31, 2024 by Union Ministry of Jal Shakti for which the ground water quality assessment was carried out by Central Ground Water Board (CGWB) provides the most thorough assessment of groundwater quality so far, using a new Standardised Operating Procedure (SOP).
The study on groundwater quality included a comprehensive reach, covering 15,259 monitoring locations, focusing particularly on shallow aquifers that provide 87 per cent of India’s agricultural and 11 per cent of domestic water needs.
Sampling was done in both pre- and post-monsoon seasons, utilising 4,982 trend stations to assess seasonal variations in contamination levels.
This report provides a comprehensive analysis of groundwater quality across India, highlighting the prevalence of key contaminants such as chloride, iron, arsenic, uranium, fluoride, nitrate, and elevated electrical conductivity (EC). The analysis based on the findings from the report is mentioned below:
Electrical conductivity (EC) and salinity
Groundwater salinity exceeds permissible EC limits across several states, with Rajasthan most affected—48.57 per cent of samples surpassing 3000 µS/cm, especially in Barmer (80.36 per cent) and Jodhpur (68.49 per cent) due to over-extraction and arid conditions. Gujarat (19.62 per cent) faces seawater intrusion, particularly in Surendranagar.
Haryana reports 23.30 per cent exceedance, with Sirsa (35.82 per cent) and Hisar (32.76 per cent) impacted by irrigation-driven over-extraction. Coastal regions also struggle with seawater intrusion.
While post-monsoon recharge offers slight relief, it fails to offset worsening long-term salinity trends.
Fluoride
The 2024 report flags fluoride as a major groundwater contaminant, with 9.04 per cent of samples exceeding the BIS limit of 1.5 mg/L.
Rajasthan is worst affected, with over 25 per cent of wells in Barmer, Nagaur and Jaipur impacted by geological factors and over-extraction.
Andhra Pradesh (18.9 per cent) and Telangana (16.5 per cent) face issues in Prakasham, Anantapur, Nalgonda, and Khammam due to rock-water interactions and agriculture.
Karnataka (15.2 per cent) and Tamil Nadu (14.8 per cent) see contamination in Bellary, Raichur, Dharmapuri, and Krishnagiri, driven by hard rock aquifers and evaporation.
Gujarat (12.4 per cent) and Punjab (11.2 per cent) report cases in Banaskantha, Patan, Bathinda, and Patiala due to fluoride-bearing minerals and groundwater depletion. The 2.27 per cent rise in affected areas since 2022 highlights the urgent need for stronger mitigation policies.
Nitrate
Nitrate contamination affects 20 per cent of groundwater samples, exceeding the BIS limit of 45 mg/L. Rajasthan is worst-hit, with over 40 per cent of samples in Ajmer and Nagaur contaminated by fertiliser use and runoff. Maharashtra follows, with 35.2 per cent of samples in Ahmednagar and Jalgaon and Tamil Nadu records 29.4 per cent exceedance in Salem and Coimbatore due to leaching.
Haryana and Delhi report 15–18 per cent contamination, notably in urban areas like Gurgaon and Southwest Delhi, linked to poor sewage management. The data underscores excessive fertiliser use as a key driver of groundwater quality degradation, worsened by inadequate nutrient management policies.
Chloride
Chloride contamination in groundwater varies regionally, with 3.07 per cent of 15,259 samples exceeding the 1000 mg/L BIS limit during pre-monsoon 2023. Rajasthan, Gujarat, and Haryana are most affected, while coastal states like Tamil Nadu and Andhra Pradesh face seawater intrusion.
In contrast, over 83.93 per cent of samples from Himachal Pradesh, Uttarakhand, and Meghalaya report chloride levels below 250 mg/L, indicating minimal contamination. The data highlights the role of hydro-chemical processes, inland salinity, and human activities, calling for focused interventions in hotspot areas.
Iron
Iron contamination affects 13.2 per cent of groundwater samples (2,016 out of 15,259) exceeding the BIS limit of 1.0 mg/L during pre-monsoon 2023. Bihar, Uttar Pradesh, Odisha, West Bengal, Jharkhand, and Chhattisgarh are most impacted, with high concentrations from weathering of ferruginous minerals.
Hotspots include Prayagraj, Balrampur, and Varanasi in Uttar Pradesh, and Bankura and Purba Bardhaman in West Bengal. Northern and Central India report higher contamination than Western India.
Arsenic
Arsenic contamination affects 3.35 per cent of groundwater samples (511 of 15,259) exceeding the BIS limit of 10 ppb in pre-monsoon 2023.
West Bengal, Bihar, Uttar Pradesh, and Assam are most impacted, with arsenic prevalent in the Ganga and Brahmaputra floodplains. In West Bengal, 79 blocks across eight districts, particularly near the Bhagirathi River, are severely affected. Chhattisgarh reports localised contamination in volcanic rocks of the Dongargarh-Kotri rift zone. Hotspots include Raipur, Howrah, Malda, and Nadia.
Contamination is typically confined to aquifers up to 100 meters deep, with deeper aquifers largely arsenic-free.
Uranium
Uranium contamination affects 6.6 per cent of groundwater samples (757 out of 11,445) exceeding the BIS limit of 30 ppb in pre-monsoon 2023.
Rajasthan and Punjab are major contributors, with 42 per cent and 30 per cent of samples surpassing 100 ppb, respectively. High levels are also reported in Gujarat, Haryana, Tamil Nadu, Andhra Pradesh, and Karnataka, often in groundwater-stressed zones.
Causes include geogenic factors like granite-rich rocks and anthropogenic inputs like phosphate fertilisers.
Hotspots such as Jaipur, Bathinda, and Ganganagar demand urgent action.
In addition to the above, the analysis of hydro-chemical facies reveals that bicarbonate and sodium dominate India’s groundwater chemistry. This cation-anion interplay worsen soil alkalinity and sodicity, particularly in agricultural zones. The linkage between sodium adsorption ratios (SAR) and residual sodium carbonate (RSC) levels and declining irrigation suitability is a critical insight. Alarmingly, 10.43 per cent of groundwater samples are unsuitable for irrigation, a trend that endangers agricultural sustainability.
Insufficient focus on groundwater governance: Despite detailed data on contamination hotspots, the report falls short in addressing governance failures and policy lacunae. For instance, over-extraction—a root cause of salinisation and uranium mobilisation—is inadequately addressed through regulatory frameworks.
Monsoon recharge— a temporary fix: The report highlights seasonal improvements in water quality, yet it does not adequately explore long-term strategies to sustain groundwater recharge or mitigate contamination.
Health impact assessment: While the report acknowledges the health risks of contaminants like arsenic and uranium, there is little emphasis on epidemiological studies or public health interventions.
Data transparency and action ability: The reliance on aggregated data limits localised decision-making. Detailed district-level interventions tailored to specific contamination profiles are noticeably absent.
Suggested Recommendations
Comprehensive Policy Reforms: Establish stringent extraction limits in over-exploited zones and incentivise water-efficient agricultural practices.
Integrated Monitoring Systems: Leverage real-time data analytics to track contamination trends and predict future risks.
Public Awareness Campaigns: Educate communities about contamination risks and promote the adoption of low-cost treatment technologies.
Targeted Remediation: Deploy region-specific solutions such as rainwater harvesting in salinity-prone areas and phosphate reduction strategies to curb fluoride and nitrate contamination.
The Annual Groundwater Quality Report is a crucial step in diagnosing India’s groundwater woes.
However, its findings also underscore the systemic inertia and fragmented efforts undermining water security. Scientific insights must translate into actionable policies and community-driven interventions to avert nearing groundwater crisis.
A holistic approach combining stringent monitoring, community engagement, technological innovation and robust policy interventions is essential to address these concerns.