Why in the news
The National Green Tribunal (NGT) voiced displeasure at how the Central Groundwater Authority (CGWA) responded to widespread arsenic and fluoride contamination of groundwater across India.
Key facts
- Natural contaminants: arsenic, fluoride, iron and uranium occur naturally in some geological deposits.
- Worst hit by arsenic and iron: West Bengal and Assam.
- Human-made causes: heavy fertiliser, pesticide and herbicide use; untreated industrial effluents; urban seepage and poor waste systems.
- Saltwater intrusion: rises when groundwater extraction speeds up, letting sea water enter freshwater aquifers.
Nitrate pollution
| Group | State (share) |
|---|
| Highest | Rajasthan (49%), Karnataka (48%), Tamil Nadu (37%) |
| Rising | Maharashtra (35.74%), Telangana (27.48%), Andhra Pradesh (23.5%), Madhya Pradesh (22.58%) |
Main contaminants and effects
| Contaminant | Source or effect |
|---|
| Arsenic | Industrial and mining discharge and thermal plant fly ash ponds; causes black foot disease |
| Fluoride | Neuromuscular and gastrointestinal disorders, dental deformity, skeletal fluorosis |
| Nitrates | Excess intake causes methemoglobinemia (blue baby syndrome) |
| Uranium | Local pockets exceed WHO-recommended levels |
| Radon | Found in some Bengaluru pockets; harms lung tissue and raises lung cancer risk |
| Other metals | Lead, mercury, cadmium, copper, chromium and nickel are carcinogens |
Way forward
- Stronger regulation of groundwater and a permit system for extraction.
- Sustainable agriculture, infrastructure investment and decentralised management.
Related initiatives
- Atal Bhujal Yojana, Jal Shakti Abhiyan, NAQUIM and PMKSY.
- Water (Prevention and Control of Pollution) Amendment Bill, 2024, along with NGT, CPCB and the Environment (Protection) Act, 1986.
About CGWA
- Constituted under Section 3(3) of the Environment (Protection) Act, 1986.
- Regulates and controls groundwater development and management, and issues directives for it.
- Uses Section 4 of the Act for appointing officers.
Exam angle
- Black foot disease: arsenic; skeletal fluorosis: fluoride.
- Blue baby syndrome: nitrates.
- Programme for aquifer mapping: NAQUIM.