'Groundwater pollution linked to Delhi landfills'

A Delhi government analysis has confirmed severe contamination of groundwater aquifers surrounding the city's saturated landfill sites at Bhalswa, Ghazipur, and Okhla.

- Paras Singh and Jasjeev Gandhiok

The assessment, which tested samples across nine parameters, found substances like chlorine, sulphate, fluoride, and hardness at levels several times higher than prescribed limits. The results, submitted to the central government, point to heavy pollution from leachate-a toxic liquid formed when water filters through long-accumulated waste-which has seeped into the groundwater systems.

According to a Delhi Pollution Control Committee (DPCC) report, the contamination near the Bhalswa landfill is particularly severe, with significant breaches of safety standards. Total dissolved solids in groundwater near Bhalswa Janata Colony were nearly six times above acceptable levels. Chlorine concentrations were recorded at three times the permissible limit of 250 mg per litre, reaching 729 mg per litre. Hardness, measured as calcium carbonate, was double the standard. Specific locations showed extreme pollution: chlorine levels hit 1269.6 mg per litre at Bhalswa Dairy, 869.7 mg per litre at Bhalswa Sanjay Gandhi Transport Nagar, and 729.8 mg per litre at Janata Colony. Hardness limits were also breached across all Bhalswa samples, with Transport Nagar recording 784 mg per litre and Bhalswa Dairy 728 mg per litre. Fluoride exceeded safe levels at Bhalswa Dairy, though nitrate levels in Bhalswa remained within standard limits.