Fish kill near Adyar eco-park highlights persisting sewage contamination

In yet another indicator of the unabating contamination of the Adyar, dead fish were seen floating near the eco-park. Sewage outfalls were also spotted at several places near Kotturpuram.

Ambika Chandrasekar, a resident of Adyar, noticed a school of fish dying and some already dead in waters near the eco-park on June 16. When The Hindu visited the place on Tuesday, a bunch of dead tilapia fish had washed up close to the compound wall of the eco-park.

A little up north of the Adyar, a feeder channel flowing through the Kotturpuram urban forest on River View Road was filled with sewage. Regular complaints over the last couple of years have not yielded any permanent solutions, says Shobha Menon of Nizhal, a non-governmental organisation (NGO) that runs the urban forest.

At the southern end of Lock Street, a constant stream of sewage was flowing into the Adyar from a channel on the banks of the river.

R. Ramasubramanian, senior fellow, Coastal Systems Research, M.S. Swaminathan Research Foundation, said an obstruction at the river mouth or sewage overload could be the primary reasons for the fish kill. Contamination can cause oxygen levels to go down, he said. 

Among a string of orders pertaining to river pollution passed by the National Green Tribunal over the last few years, in November 2022, the Southern Bench had directed the State government to clean up rivers in Chennai, including the Adyar. However, sewage from multiple drains continues to contaminate the river.

An official with the Chennai Rivers Restoration Trust told The Hindu that the issue would be taken up with the respective area engineer of the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) and the sewage outfall would be stopped. 

Sources in the CMWSSB said action would be initiated to plug sewage outfalls in the river. Pointing out that the water agency had already started plugging sewage outfalls in the city limits of the river, sources said new sewage pumping stations have been constructed in various places such as Kotturpuram, Nandanam, Saidapet, and Ekkaduthangal recently to intercept sewage reaching the river and diverting them to sewage treatment plants.

Measures are being taken to identify more locations and chalk out projects to arrest pollution in the Adyar. They alleged that commercial establishments close to the river illegally released sewage into the waterway.

(With inputs from K. Lakshmi)