Fish Kill due to effluent discharge in the Kaveri

Mettur, 05, February, 2008 – A massive fish kill of tilapia and an eel-like freshwater fish was reported down stream of Chemplast Sanmar’s effluent discharge point in the River Kaveri on 3rd February. The fish kill occurred in a natural rock pool called Sunambu Kuttai, about 100 meters downstream of Chemplast’s discharge point in the surplus course of the Kaveri. Fish kills in this pond are a routine phenomenon, with similar kills reported in November 2004, And July 2006. Chemplast Sanmar Ltd has 4 effluent discharge outlets from its PVC and Chloro chemical units in Mettur opening into the surplus flow of the river Kaveri. A complaint has been filed against the company with the Karumalaikoodal police station by Gonur west Agriculturist’s Development Union, a local farmer’s body.


Such fish kills are routinely hushed up by the regulatory authorities. After each fish kill the Tamilnadu Pollution Control Board only took samples of the water. No fish samples were taken. The conclusion in both cases was that the fish had died due to a lack of dissolved oxygen. No mention was made as to the reasons why the water was suddenly starved of oxygen and who was responsible for the pollution.


An air sample taken from the discharge point at Kaveri in April 2005 by Community Environmental Monitoring identified the presence of 17 chemicals including Hydrogen sulphide at 400 times above the safe limit. “The high levels of hydrogen sulphide in samples of air above the effluent stream are a very strong indication that the effluents contain high levels biological oxygen demand (BOD) that Chemplast is failing to treat. When a polluter discharges high levels of BOD into a stream, it depletes oxygen levels in the stream and promotes the conversion of sulphur compounds into H2S, which evolves from the stream as a gas”, according Dr. Mark Chernaik of ELAW-US.


A November 2007 report titled “Unfolding Disaster” reports the results of samples of PVC effluent taken from the surplus course. This analysis found 28 chemicals including 6 that were above levels considered safe by7 the USEPA. These chemicals include 1,2-dichloroethane, 1,1,2-trichloroethane, 1,2-dichlorobenzene, benzene, and vinyl Chloride. In effect, even if the fish weren’t dying they are highly likely to be severely contaminated with toxic chemicals.


A fish study conducted by Dr. M. Arunachalam, an expert in the ecology of lakes and streams and Dr. M. Muralidharan confirms that the fish diversity downstream of the Kaveri beneath the Chemplast discharge point is characterised by low or no fish population.

Fish Kill due to effluent discharge in the Kaveri
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