Delhi’s Drain Pollution Spikes Despite Rainfall

Pollution levels in Delhi’s major drains surged in June despite heavy rainfall the previous month, with key inflows into the Yamuna—like Najafgarh, Shahdara, and Sahibabad—recording high levels of BOD, COD, and TSS. The Delhi Pollution Control Committee’s latest assessment found water quality far above permissible limits, raising alarm over sewage management and the effectiveness of ongoing river-cleaning efforts.

According to the June report by the Delhi Pollution Control Committee (DPCC), the Najafgarh, Shahdara, and Sahibabad drains registered alarming chemical pollution levels. BOD readings in Sahibabad hit 185 mg/l, more than six times the permissible 30 mg/l. Shahdara followed with 110 mg/l, while Najafgarh reached 72 mg/l—higher than both the previous month and the same period last year.

TSS and COD levels also spiked. The Sahibabad drain recorded TSS at 336 mg/l and COD at 543 mg/l, far above the standards of 100 mg/l and 250 mg/l respectively. Even the Najafgarh drain, one of the largest contributors to Yamuna pollution, saw all three parameters increase from May. These figures suggest a significant rise in untreated effluents entering the river system.

Although May experienced record rainfall, which typically helps dilute pollutants, the analysis revealed that such natural intervention had little impact on drain toxicity. Experts attribute the continued pollution surge to unchecked sewage inflow and poor implementation of waste treatment policies. Notably, the DPCC report omitted faecal coliform data, a crucial indicator of untreated human waste in water.

The Yamuna river itself remains highly polluted, with the DPCC noting elevated ammonia and faecal coliform levels at both the river’s entry point at Palla and exit at Asgarpur. Ammoniacal nitrogen nearly doubled from April to May. Drains like Maharani Bagh and Shahdara continue to push high pollution loads into the river, undermining the city’s clean-up campaigns and riverfront restoration plans.

The spike in pollution across Delhi’s major drains underscores the failure of stormwater dilution and exposes gaps in sewage treatment infrastructure. With key drains breaching environmental safety limits and the Yamuna continuing to carry a toxic load, urgent policy action and strict enforcement of treatment norms are critical. Without robust interventions, Delhi’s water pollution crisis may worsen, threatening both public health and ecological sustainability.

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Delhi’s Drain Pollution Spikes Despite Rainfall