The Tamil Nadu government rejected a report by the Centre on groundwater contamination in Thoothukudi, saying that the study was biased in favour of Vedanta’s Sterlite Copper plant. Tamil Nadu Chief Secretary Girija Vaidyanathan wrote to the secretary of the Union Ministry of Water Resources requesting a withdrawal of the study conducted by the Central Ground Water Board, The Hindu reported.

The Tamil Nadu official’s letter on Friday said the report could worsen the law and order situation in the district, which had just returned to normalcy. In May, 13 people protesting against the expansion of the Vedanta Group’s Sterlite Copper plant in the coastal city were killed in police firing. Several people were arrested for rioting, burning of vehicles on the Tuticorin collectorate campus, stone pelting and damaging public property.

“The state strongly feels that the report is motivated and has been prepared only to prejudice the government and TNPCB [Tamil Nadu Pollution Control Board] cases in various courts,” Vaidyanathan said in her letter, according to IANS. “It does not appear to be made on any scientific basis and it is not known how the two scientists who have submitted the report have made such a vague and an unsubstantiated statement in the report,” Vaidyanathan said.

She expressed the state government’s disappointment that the Centre had decided to commission a study on the matter without intimating the state officials concerned. Vaidyanathan said that according to the study the investigation team could not enter the industry premises for collection of representative samples as district authorities had sealed the plant. “Therefore, it can’t be stated that Sterlite Industry is the only cause of pollution,” she quoted from the concluding paragraph of the study.

She said the state pollution control board had conducted studies before ordering the closure of Sterlite copper smelter plant. The state government permanently had shut down the Sterlite plant in May, days after the protests.

Dravida Munnetra Kazhagam President MK Stalin expressed his shock at the “pro-Sterlite analysis” of the report, accusing the Bharatiya Janata Party and the All India Dravida Munnetra Kazhagam of joining hands to reopen the plant. In a tweet on Sunday, he said: “The Union Ministry of Water Resources conducted groundwater analysis independently in and around of Thoothukudi.” The DMK leader asked the government to withdraw the report immediately.

For more than two decades, activists in Thoothukudi have accused Sterlite of contaminating the region’s air and water resources and causing breathing disorders, skin diseases, heart conditions and cancer. From February, there were large-scale protests against the company’scopper smelter, which had the capacity to produce 4.38 lakh tonnes of anodes per annum, or 1,200 tonnes per day.

On August 14, the Madras High Court ordered the Central Bureau of Investigation to conduct an inquiry into the police’s decision to fire at protestors.