Gas turbines at xAI’s power plant in Southaven, Mississippi, which supplies its Colossus 2 data centre in Memphis, Tennessee.
A federal judge in Mississippi has refused to throw out the NAACP’s Clean Air Act lawsuit against xAI. The case is over the gas turbines that power its Colossus 2 data centre. Judge Debra M. Brown ruled on Friday that the turbines are not exempt from air permits as “mobile sources”.
She also rejected xAI’s argument that lawsuits brought by citizen groups under the Clean Air Act are unconstitutional. Earthjustice represents the NAACP with the Southern Environmental Law Center. It published the court’s opinion and a statement on the ruling. xAI is now part of SpaceX.
“Because citizen suit plaintiffs sue on their own behalf, in their own name, and seek penalties that redress harm to themselves, they are not exercising the federal government’s executive power.” Judge Debra M. Brown, in her opinion
The NAACP and its Mississippi State Conference sued xAI and its subsidiary MZX Tech in April. The complaint says the companies installed gas turbines at the Southaven plant between August and December 2025 without permits. By April there were at least 27 turbines, the complaint says. Together they can generate at least 495 megawatts.
The NAACP says they could emit about 1,700 tons of nitrogen oxides a year, a main cause of smog. It wants a court to order pollution controls. It also seeks civil penalties of up to $124,426 a day for each violation.
In July 2025, Mississippi’s environmental regulator told xAI the turbines would be exempt from permits. It called them mobile, because each sat on a trailer. It also called them temporary, because each would stay less than 12 months. The company argued it relied on that view.
The judge found the regulator had “fairly notified” xAI of its position. But she said the court was not bound by it. Under the federal rules that Mississippi’s plan adopts, the plant is not a mobile source, she wrote. SpaceX has not commented publicly on the ruling.
The same court ruled against the US Justice Department on 19 October. The department had asked it to dismiss the case, after it backed xAI in June . The court let the department join the case but not end it, the Southern Environmental Law Center said .
The court has yet to rule on the NAACP’s request for a preliminary injunction. Residents near the plant have also filed a noise class action , and xAI has offered to buy nearby homes from owners who drop their claims.
On Tuesday, voters in 10 US states will decide on measures to limit data centres, Courtney Rozen reported for Reuters .
“The courts have repeatedly rejected attempts by xAI and the DOJ to dismiss the NAACP’s Clean Air Act case.” Abre’ Conner, NAACP director of environmental and climate justice, in a statement
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