India, Aug. 7 -- The Central Ground Water Board (CGWB) has detected nitrate levels above the permissible limit in groundwater across parts of 502 districts in 26 states and Union Territories, the government informed Parliament on Friday.

Citing CGWB's 2025 Annual Ground Water Quality Report, Minister of State for Chemicals and Fertilisers Anupriya Patel told the Lok Sabha in a written reply that 20.71 per cent of the groundwater samples analysed showed nitrate concentrations exceeding the permissible limit of 45 mg per litre.

"Nitrate contamination above the permissible limit has been observed in parts of 502 districts across 26 states/UTs," the minister said.

She was responding to a question from Congress MP Prabha Mallikarjun, who re...