Heavy Metal Contamination in Delhi's Groundwater

Delhi's groundwater contamination is a significant environmental issue, with high levels of uranium, lead, nitrate, fluoride, and salinity-related indicators.

Key Findings from Central Ground Water Board's Report

• Delhi exhibits one of the highest levels of lead contamination, impacting cognitive development, blood pressure, kidney function, and posing carcinogenic risks. 
  • 9.3% of samples exceeded permissible limits compared to 3.23% in Assam and 2.04% in Rajasthan.
• Uranium levels in Delhi are high, with 13-15% of samples surpassing permissible limits.
• Nitrate contamination, driven by agricultural and waste disposal practices, poses additional health risks.
• Fluoride concentrations, mainly geogenic, arise from water-rock interactions in certain aquifers.
• Electrical Conductivity (EC) as an indicator of salinity is concerning, with 23.3% of samples exceeding limits.

Health and Environmental Impacts

• High uranium levels, electrical conductivity, and Sodium Adsorption Ratio (SAR) impact water usability for agriculture and industries.
• High levels of contamination detected in monsoon and post-monsoon samples.
• NaCl-type salinity and CaCl₂-type hardness noted, with significant implications for water use.

Recommendations and Actions

• Environmental groups call for public disclosure of groundwater quality data and action plans.
• CPCB's recommendations include: 
  • Source protection and improved fertilizer management.
  • Targeted treatment technologies and strict industrial effluent regulation.
  • Hotspot monitoring and hydrogeochemical mapping.

Public and Institutional Response

• Earth Warrior demands transparency from Delhi Jal Board on water quality and treatment methods.
• Calls for compliance with Bureau of Indian Standards (BIS) for safe drinking water.