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Toxic mix of effluents causing mass fish deaths in Delhi's Najafgarh drain: Activist
Thousands of dead fish were seen floating in the Najafgarh drain near the Dhansa regulator, with activists blaming untreated residential effluents and industrial waste, possibly worsened by rising temperatures. A Delhi Pollution Control Committee analysis in March reported high biological oxygen demand in the drain's downstream area, and experts warned of mixture toxicity, calling for investigation.
Why It Matters
The incident highlights ongoing pollution of the Najafgarh drain and its connection to the Yamuna, raising concerns about ecosystem health and potential public health implications.
Timeline
3 Events
Experts call for investigation; discussion of mixture toxicity
April 22, 2026
Radhey Shyam Sharma, head of Delhi University's Department of Environmental Studies, and Bhim Singh Rawat urged a proper investigation and immediate action to rectify the imbalance. Sharma highlighted that mixture toxicity—where multiple pollutants interact—can cause greater harm than individual pollutants and warned of the ecosystem stress in the Najafgarh system.
Mass fish deaths observed in Najafgarh drain near Dhansa regulator
April 22, 2026
Thousands of dead fish have been seen floating on the Najafgarh drain near the Dhansa regulator, with activists noting the incident occurring near Rawta village on the Delhi-Haryana border. Activists attribute the deaths to excessive inflow of untreated residential effluents and industrial wastes, possibly compounded by an increase in temperature that may have lowered dissolved oxygen levels.
DPCC March 2026 analysis shows high BOD in Najafgarh drain
March 2026
A Delhi Pollution Control Committee analysis published in March showed that the biological oxygen demand (BOD) at Najafgarh Jheel Downstream was 60 mg/l, compared to the desired standard of 30 mg/l. The report also indicated that multiple subdrains of the Najafgarh canal have BOD levels well above the safe limit.