The Southern Environmental Law Center, suing on behalf of the NAACP, alleges xAI installed and operated at least 35 combustion turbines at the Colossus site without obtaining preconstruction or operating air permits, in violation of the Clean Air Act. The NAACP filed the suit in April.

xAI argued the turbines were exempt from permitting because they are mobile, and that the plaintiffs lacked standing to sue. Judge Brown rejected both arguments, finding the turbines are not mobile sources under Mississippi's State Implementation Plan and that citizen suit plaintiffs sue on their own behalf, so they are not exercising federal executive power. A similar motion to dismiss from the Department of Justice, which had backed xAI's position, was denied earlier this month.

NAACP environmental and climate justice director Abre' Connor called the ruling "another important victory in our effort to hold xAI accountable", noting that courts have repeatedly rejected dismissal attempts by xAI and the DOJ. The case moves forward amid wider public backlash against data centre buildouts, including a New York moratorium on new data centres.