Elon Musk’s xAI, now owned by SpaceX, is facing a new legal challenge from environmental groups in Mississippi, where the company plans to build a massive, methane gas-burning power plant in the town of Southaven.

Nonprofits including the NAACP, Young, Gifted & Green, and the Safe and Sound Coalition want Mississippi to revoke the permit that the state’s environmental regulator granted to xAI last month allowing it to build the plant. Members of the groups live near xAI’s local operations.

The power plant will “worsen the region’s ongoing ozone problem,” the groups’ lawyers wrote in a petition filed to the state on Thursday, and result in “significant increases of pollutants like nitrogen dioxide and, relatedly, fine particulate matter,” that would harm air quality and threaten the health of residents.

Musk’s company obtained the permit from the Mississippi Department of Environmental Quality on March 10, enabling it to install 41 natural gas-burning turbines permanently in DeSoto County, Mississippi, in order to power its nearby data centers.

XAI currently operates a data center called Colossus 2 in Memphis, Tennessee, just across the state line, and is building out a new facility dubbed Macrohardrrr in Southaven.