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The Tamil Nadu government had argued in court that the deaths in police firing were not the only reason why the plant was shut down. It said the Sterlite plant was a big threat to the environment and ecology, and pollutants released by Sterlite were much higher than other companies in the area.
The National Green Tribunal gave a favourable order to Sterlite in December 2018. However, the Supreme Court struck it down over jurisdiction issues and ordered Vedanta to approach the Madras High Court, after which the company filed multiple petitions in February last year.
"The order to shut down the copper smelting plant was perfectly justified and was in line with the law of the land laid down by the Supreme Court," senior counsel CS Vaidyanathan, appearing for the Tamil Nadu government, had told the court.
The closure of the "red category" smelter with a capacity of four lakh tonnes and employing 800 permanent and 3,500 contract workers in Tuticorin and other parts of India had led to 40 per cent fall in copper production in India.
The smelter in Tuticorin accounted for over a third of India's refined copper output before it was shut. The country later imported 44,000 tonnes of copper against 3.3 lakh tonnes exported in 2017-18.
Sterlite Copper CEO Pankaj Kumar said the firm will pursue all legal remedies. "We firmly believe in safe and environmentally sound nature of our operations. The nation has been forced to depend on hostile neighbours for copper import. Certain forces are conspiring to stifle our nation's ability to be an independent copper manufacturer," Mr Kumar said.
"The verdict comes as an utter shock to the employees of Sterlite Copper and the thousands of small businesses, entrepreneurs and community members dependent on our continued operations," Mr Kumar said.
In 2016, the Supreme Court had imposed a fine of Rs 100 crore on Sterlite for pollution and misrepresentation between 1996 and 2012.
In March last year, Vedanta named metals industry veteran Pankaj Kumar as Sterlite Copper chief executive. Mr Kumar replaced P Ramnath, who led Sterlite for eight years. Under Mr Ramnath, the smelter was ordered shut at least twice, including for an alleged gas leak in 2013.
The protest against Sterlite Copper was the deadliest at an environmental protest in India in a decade. A working group of United Nations' human rights experts in May 2018 condemned the "apparent excessive and disproportionate use of lethal force by police".