Groundwater Crisis: CGWB Flags Widespread Contamination in Andhra Pradesh

News Context

1. Report Context and Source

• Official Assessment. The Central Ground Water Board (CGWB) released its **Annual Ground Water Quality Report, 2025**, documenting critical levels of pollutants in the state’s aquifers.
• Accessing the full report. The detailed findings regarding these health hazards are available here: The Hindu – CGWB Report https://epaper.thehindu.com/ccidist-ws/th/th_international/issues/165840/OPS/GMFFD491A.1+GS9FE7FQH.1.html
• Scope of study. The findings are based on extensive groundwater sampling conducted between **June 2024 and March 2025**, following a new Standard Operating Procedure (SOP) to ensure national uniformity.

2. High-Risk Contaminants and Hotspots

• Uranium Threats. Sporadic spikes exceeding the safety limit of **30 parts per billion (ppb)** were found, particularly in hard-rock belts.
• Sri Sathya Sai District: 16 villages identified with toxic levels.
• Tirupati District: 3 villages flagged as high-risk zones.
• Arsenic Hotspots. Five specific villages were identified where concentrations exceeded **10 ppb**:
• Mulapalem (Bapatla), Varagami (Guntur), Kartamodu (Nellore), Rompicherla (Palnadu), and Kurichedu (Prakasam).
• Fluoride Concentration. Over-extraction from hard rock aquifers has mobilized fluoride minerals, pushing levels above the permissible **1.50 mg/l** in several regions.

3. Coastal and Soil Integrity Issues

• Seawater Intrusion. Coastal aquifers are increasingly facing salinity ingress. High **Electrical Conductivity (EC)** levels (exceeding 3000 µS/cm) confirm that seawater is encroaching into freshwater zones due to over-pumping.
• Irrigation Hazards. High levels of **Residual Sodium Carbonate (RSC)** were found in **26.87%** of samples analyzed—the second-highest incidence in India after Delhi. This poses a significant threat to soil structure and long-term agricultural productivity.
• Toxic Cocktail. Other notable pollutants detected include Nitrate (linked to fertilizer runoff), Iron, Chromium, Lead, and Cadmium.

4. Impact of Seasonality and Over-Extraction

• The Monsoon Factor. The report notes a slight improvement in water quality following the monsoon due to natural recharge, which diluted EC and fluoride levels in some areas.
• Geogenic vs. Anthropogenic. While much of the fluoride and uranium contamination is **geogenic** (naturally occurring in rocks), the CGWB warns that **indiscriminate over-extraction** is the primary driver accelerating the release of these toxins into drinking water.

5. Health and Policy Implications

• Health Risks. Widespread contamination is linked to serious conditions such as dental/skeletal fluorosis, kidney issues (uranium), and potential carcinogenic risks (arsenic/lead).
• Urgent Recommendations. The CGWB has advised immediate “source blending” (mixing contaminated water with safe surface water) and the installation of specialized Reverse Osmosis (RO) and de-metalization units in the flagged hotspots.