New govt study shows high groundwater contamination in some areas

New Delhi: A recent report by the Central Ground Water Authority (CGWA) reveals persistent high concentrations of heavy metals in groundwater near the Union Carbide pesticide plant. Following a media report flagged by the National Green Tribunal (NGT) in December, CGWA launched an investigation into potential groundwater contamination around the Union Carbide India Limited (UCIL) premises. This study involved field surveys and laboratory tests, with 72 groundwater samples collected within a five-kilometer radius of UCIL.

The report to the NGT revealed that at seven out of 36 locations, nitrate concentrations exceeded BIS desirable limits. Phosphate levels surpassed WHO limits at two sites. Some areas showed elevated calcium and magnesium levels, exceeding BIS standards. Sodium concentrations exceeded WHO limits at two locations, and potassium levels surpassed World Health Organization (WHO) limits at 27.77 per cent of sites. Nearly all samples were classified as hard or very hard water.

The study found pH values within permissible levels, with water conductivity below BIS limits and no carbonate ions present. Total alkalinity remained within acceptable ranges, while chloride levels indicated some pollution. Iron levels exceeded BIS standards at eleven sites, peaking at 11.664 mg/l. Manganese pollution affected 8.33 per cent of locations, surpassing BIS limits.

“Zinc contamination was minimal, with only one location exceeding the BIS-acceptable limit but remained under the permissible limit. Arsenic concentrations were generally below BIS limits, except for one location,” the report read.

Strontium, not regulated either by BIS or WHO standards, was reported at concentrations from ‘0.198’ to 2,223 mg/l with an average of 0.833 mg/l. Over 600,000 people were exposed to the deadly gas, with around 15,000 fatalities. Research indicates that those born after the disaster suffer from cancer, disabilities, and poverty.