Central Ground Water Board (CGWB) – Annual Groundwater Quality Report, 2025

India is among the world’s largest users of groundwater. A major share of drinking water, agriculture, and industrial needs is fulfilled through groundwater. Hence, assessing its quality is crucial. The Annual Groundwater Quality Report 2025, released by the Central Ground Water Board (CGWB), presents the current status, major contaminants, and regional patterns of groundwater pollution across India.

Report

1. Overall Quality Status

• 71.7% of India’s groundwater samples meet the Bureau of Indian Standards (BIS) norms.
• 28.3% samples contain one or more contaminants beyond the permissible limits.

Why this matters

→ Over 80% of rural drinking water in India depends on groundwater. Any deterioration in quality directly threatens public health and water security.

Major Contaminants

(A) Nitrate – The Most Widespread Contaminant

• 20% samples exceed the WHO/BIS limit of 45 mg/L.

Main sources

• Excessive fertilizer application
• Sewage percolation
• Animal waste infiltration

Health impacts

→ Blue Baby Syndrome, cancer risks, thyroid issues.

(B) Uranium Contamination

• Pre-monsoon: 6.71% samples above the safe limit (30 ppb).
• Post-monsoon: 7.91% samples above the limit.
• Most affected regions: Punjab, followed by Haryana and Delhi.

Source

→ Mostly geogenic (leaching from rocks), but aggravated by groundwater over-extraction.

(C) Salinity (Electrical Conductivity)

• 7.23% samples exceed the prescribed limit.

Highly affected regions

• Rajasthan
• Delhi
• Other arid/semi-arid regions

Causes

→ Over-pumping, low recharge, seawater intrusion in coastal areas.

(D) Fluoride

• 8.05% samples exceed BIS limits.
• Largely geogenic.

Worst-affected state

→ Rajasthan

Health impacts

→ Dental and skeletal fluorosis.

(E) Lead (Pb)

• Highest concentrations reported in Delhi.

Health impacts

• Impaired cognitive development
• Increased blood pressure
• Kidney damage
• Classified as a potential carcinogen

(F) Other Contaminants

• Arsenic
  • Ganga–Brahmaputra basin: Bihar, West Bengal, Assam
• Manganese
  • Assam, Karnataka, Odisha, Uttar Pradesh, West Bengal
• Iron, cadmium, chromium in industrial clusters

Groundwater for Irrigation

• 94.30% of samples fall under the “Excellent” category.
  → Groundwater is largely suitable for agricultural usage.

Trends in Groundwater Quality

• Pre-monsoon quality is generally poorer.
• Slight reduction in dissolved contaminants after monsoon recharge.
• States with heavy groundwater extraction (Punjab, Haryana) show rising contamination.
• Urban areas exhibit higher heavy-metal contamination than rural regions.

Central Ground Water Board (CGWB)

Significance of the Report

(i) Environmental–Health–Agriculture Linkages

Groundwater pollution affects health (nitrate, fluoride, arsenic), drinking water access, and food security.

(ii) Climate Change Impact

Lower recharge in drought-prone regions increases contaminant concentration.

(iii) Groundwater Over-extraction

~14% of India’s blocks are “over-exploited”, increasing geogenic contaminant mobilization.

Policy Recommendations

1. Nitrate Management

• Fertilizer regulation
• Promotion of organic agriculture
• Proper sewage treatment systems

2. Uranium/Fluoride Reduction

• Defluoridation and de-metalization units
• Expanding groundwater recharge structures

3. Salinity Control

• Artificial recharge
• Monitoring freshwater–saline water interface
• Barrier wells in coastal regions

4. Urban Groundwater Safety

• Heavy-metal monitoring
• Treatment of industrial effluents

Conclusion

The CGWB Groundwater Quality Report 2025 shows that while most groundwater in India is safe, contaminants like nitrate, uranium, fluoride, arsenic, and salinity pose serious regional challenges. Ensuring groundwater safety requires scientific management, recharge enhancement, better farming practices, and strict control of pollution sources. The report offers valuable insights for policy formulation, sustainable water management, and long-term water security.