Hundreds of dead fish turn up in Najafgarh drain, DPCC collects water samples

The standard for BOD in drains is 30 mg/l. But as per the DPCC’s latest monthly report on Delhi drains, compiled on June 1, 2022, the Najafgarh drain has a BOD reading of 70 mg/l and a COD reading of 346 mg/l.

Hundreds of dead fish were found in the Najafgarh drain by residents over the past one week, prompting the Delhi Pollution Control Committee (DPCC) to collect samples from the drain on Sunday to determine the biological oxygen demand (BOD) and the chemical oxygen demand (COD) levels of the drain, which connects the Najafgarh Jheel to river Yamuna.

Hundreds of dead fish turn up in Najafgarh drain, DPCC collects water samples (PTI)

While no dead fish were found in and around Najafgarh Jheel, residents said a similar occurrence was seen across village ponds in the area, but these not connected to the drain in anyway, they said.

COD is the total measure of chemicals (organics and inorganic) in the water/waste water, while BOD is a measure of the amount of oxygen required for bacteria to decompose organic components present in water.

The standard for BOD in drains is 30 mg/l. But as per the DPCC’s latest monthly report on Delhi drains, compiled on June 1, 2022, the Najafgarh drain has a BOD reading of 70 mg/l and a COD reading of 346 mg/l, as opposed to a prescribed limit of 250 mg/l, DPCC officials said.

“If fish were dying only in the drain, then it is understandable. However, almost all fish in our village pond have died and that means it is probably not connected to effluent discharge or pollutants from nearby industries,” said Jitender Yadav, 31, a resident of Jhuljhuli village near Najafgarh drain.

He said after locals came across the dead fish, they informed officials from the forest and wildlife department, who were preparing the soil for sapling plantation work in Najafgarh.

A senior forest official, on condition of anonymity, confirmed the incident and said several hundreds of dead fish were found on the banks of the drain.

“Our teams were preparing the soil for the upcoming plantation drive and saw the dead fish; we then informed the Delhi Pollution Control Committee,” said the official.

Ravi Phalswal, another local from Rawta village, said the fish started turning up dead around 15 to 20 days ago, with the number growing considerably over the past one week.

“At first, it was only a few fish here and there, but we are now seeing them in plenty along the drain and in village ponds. Such an incident has not happened in the recent decade at least,” he said.

The DPCC said samples were collected on Sunday, and if oxygen content drops in any aquatic body, it becomes difficult for marine life to sustain itself. “We will look at different parameters to ascertain what may be the possible reasons causing the fish to die ,” said a DPCC official, asking not to be named.