Sterlite slag disposal: TN says company dumps 8 lakh tonnes of waste every year

The Tamil Nadu government on June 30 told the Madras High Court that the Sterlite copper smelting plant in Thoothukudi has dumped 5,37,765 tonnes of copper slag at different places including the banks of Uppar river.

Earlier, activist R. Fatima had filed a public interest litigation (PIL) in the HC drawing attention to the environmental hazards of dumping slag in the open.

Copper slag is a by-product of the smelting process required to manufacture copper from its ore. The raw material that floats on top of the molten copper is an impurity which is mixed with water to form angular granules called copper slag.

The slag, though an environmental hazard, can be used for various purposes like laying roads. However, as per Central Pollution Control Board norms, it needs to be scientifically verified for safety before being put to use again.

The Tamil Nadu government also gave a semblance of the volume of waste generated by Sterlite when it told the High Court that the copper slag was generated in the ratio of 1:2, which means two tonnes of slag for every tonne of copper anode produced.

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Since the Sterlite plant in Thoothukudi produces about 1,200 tonnes of copper anode a day, the everyday production of slag amounts to 2,400 tonnes and yearly generation goes up to about 8 lakh tonnes. Disposing of this huge amount of trash was a challenge perceived beforehand, and the state government in 2012 had given clear instructions to the Sterlite management to ensure the slag is disposed of scientifically. However, an inspection in 2017 revealed about 3.25 lakh tonnes of slag dumped along the Uppar Odai. Additionally, about 11,000 tonnes of slag was found in Silukanpatti village and 13,000 tonnes in the SIPCOT industrial complex.

It was the company’s lackadaisical approach towards scientific processing of the waste which led to the High Court on August 18, 2020, upholding the permanent closure order issued against the controversial copper manufacturing plant.

The Tamil Nadu government has suggested an independent environmental assessment of the dumping sites from an accredited agency and subsequent scientific remedial measures. The state government said any decision regarding reopening of the plant should be taken only after this process.

Sterlite counsel sought more time to file a rejoinder therefore the Madras High Court adjourned the case by two weeks.