SYLLABUS
GS-3: Conservation, environmental pollution and degradation, environmental impact assessment
Context: According to the Annual Ground Water Quality Report 2025 released by the Central Ground Water Board, 28.3 per cent of groundwater quality assessment samples exceeded the permissible limit set by the Bureau of Indian Standards for one or more parameters, indicating localised quality concerns.
Key Findings of the Report
- Major Contamination:
- Nitrate: Highest in Rajasthan (50.5%), Karnataka (45.5%), Tamil Nadu (36.3%); caused by fertilizers, sewage, animal waste.
- Uranium: Peaks in Punjab (62.5% post-monsoon), Haryana (40-50%), Delhi (13-15%); caused by geogenic activity and worsened by extraction.
- Fluoride: Rajasthan (41%), Telangana, Andhra Pradesh; mostly natural from rocks.
- Salinity/EC: Arid areas like Rajasthan (47%), Delhi (33.33%, 2nd worst); unfit for drinking/irrigation.
- Heavy Metals: Arsenic in Gangetic plains (WB, Bihar); Lead highest in Delhi; Manganese/Iron in Assam, East India.
Causes of Groundwater Contamination
- Geogenic Factors: Natural rock weathering releases fluoride, uranium, and arsenic into groundwater. Depletion brings deeper contaminants to the surface. Alkaline soils and bicarbonates increase uranium solubility.
- Anthropogenic Factors: Agriculture uses 87% of groundwater extraction. It causes fertilizer and pesticide runoff that raises nitrate levels, while industries release heavy metals like lead, sewage leaks, animal waste pollute water, urbanization reduces recharge through paved surfaces, and excessive deep pumping concentrates contaminants.
Government Initiatives
- Jal Jeevan Mission (JJM): JJM prioritizes BIS:10500 standards for potable tap water, allocates 10% funds to chemical contaminant-affected areas, and disseminates the 2021 Drinking Water Quality Monitoring Framework.
- Testing Infrastructure: 2,180 labs operate nationwide; 5 village women per community receive training in Field Test Kits (FTKs) for regular testing and remediation.
- Community Purification: States/UTs install Community Water Purification Plants (CWPPs) in contaminated habitations to supply safe water.
- CGWB Monitoring: CGWB disseminates data through Annual Reports, Bulletins, and Alerts; it adopts a new Standard Operating Procedure (SoP) for frequent sampling in vulnerable areas.
- Arsenic Remediation: CGWB develops cement sealing for 525 Arsenic-free wells (e.g., 294 in UP, 191 in WB); it provides technical aid to states.
- Recharge Programmes: Jal Shakti Abhiyan, JSJB, Atal Bhujal Yojana, PMKSY, and MGNREGS promote dilution of contaminants through artificial recharge.
- Surface Water Cleanup: NMCG and NRCP fund STPs/ETPs; CPCB enforces Water Act 1974 and EPA 1986 standards through SPCBs.
About the Central Ground Water Board (CGWB)
- CGWB is a scientific department under Department of Water Resources, Ministry of Jal Shakti.
- The Central Ground Water Board was formed in 1970 by renaming erstwhile Exploratory Tube well Organization. Subsequently, Ground Water Division of Geological Survey of India got merged with it in 1972.
- With its headquarters at Faridabad, CGWB has 18 Regional Offices.
- As part of the National Aquifer Mapping and Management Programme (NAQUIM), CGWB undertakes comprehensive aquifer mapping and conducts analysis of groundwater levels and quality of the study area.
- Central Ground Water Board is also discharging the functions as Central Ground Water Authority (CGWA) to regulate and control the development and management of ground water in the country since 1997.