Elon Musk’s xAI has been illegally operating dozens of natural gas turbines to power its Colossus data centers in Tennessee, the Environmental Protection Agency ruled Thursday. The AI company has argued that because the turbines were being used on a temporary basis, they were exempt from regulations. The EPA disagreed and issued its final rule on the matter, which has been in the works for over a year, declaring that xAI was in violation.

The power plants drew the ire of local communities and legal organizations. The company was facing a lawsuit for contributing more ozone and particulate emissions in an already polluted region. The company was operating as many as 35 turbines, and only 15 were ultimately permitted. Today, xAI has 12 turbines providing power to its data centers there.