Thoothukudi: Vedanta Ltd said on Wednesday a sulphuric acid leak from a tank at its Sterlite copper smelter was severe and inaction could lead to serious environmental consequences.
The district administration had said on Sunday the leak was minor, and steps were being taken to empty the storage tanks as a safety precaution.
"There is a severe leakage in the pipe flanges and ... the pipe flanges are submerged in the acid pool collected in the dykes around the acid storage tank," the company said in a petition to the Madras high court.
Vedanta, the Indian subsidiary of London-listed Vedanta Resources, said it sought a limited reconnection of the electricity supply for maintenance to guard against a potential loss of life and damage to air and ground water.
"There is a grave risk and danger as there are other tanks and there are flammable chemicals and materials within the plant area," it said.
However, the district's top administrative official Sandeep Nanduri stuck to the earlier view that the leak was minor.
"That is their version, and this is ours. However, we are completely evacuating the sulphuric acid from all tanks as a safety precaution," said Nanduri.
The Tamil Nadu state government ordered a permanent closure of the plant and disconnected the power supply last month following protests that turned violent and culminated in the police opening fire on protesters, killing 13 of them.
The protesters demanded a permanent shutdown of the plant, which they said was causing air and water pollution. Locals and activists see the smelter as a risk to fisheries. Vedanta says the protests are based on false notions.
Vedanta also said it was unable to meet government officials because of the tense situation prevailing after the protests.
A senior state minister told Reuters in an interview early this month that there was "no question" of engaging with the company, and the plant will remain shut.
The smelter, which has been shut for about three months, annually produces about a million tonnes of sulphuric acid, a corrosive byproduct of copper smelting used as a raw material by the fertiliser industry.
It accounted for over a third of India's refined copper production, and employed over 3,000 people. The company plans to appeal the government's move to shut the plant.