NAACP sues xAI over gas turbines it ran without permits for Colossus 2

The NAACP and its Mississippi State Conference sued xAI and its affiliate MZX Tech on April 14 in federal court in the Northern District of Mississippi. The suit, brought under the Clean Air Act with the Southern Environmental Law Center and Earthjustice as counsel, centers on 27 gas turbines in Southaven, Mississippi.

Those turbines had been running since the summer of 2025 to power Colossus 2, xAI’s supercomputer across the state line in Memphis, without an air permit. Mississippi regulators had treated them as “temporary-mobile” units, a category exempt from permitting if used for less than a year.

The permit came later

On January 15, the EPA revised its performance standard for gas turbines. SELC says the rule confirms that turbines like these, including ones run for less than a year, need permits.

On March 10, Mississippi’s Environmental Quality Permit Board unanimously approved a permit for MZX Tech to install 41 gas turbines in Southaven, replacing the 27 that had been running without one. The NAACP is appealing that permit as well.

What’s at stake

The NAACP estimates the plant could emit more than 1,700 tons a year of nitrogen oxides, 180 tons of fine particulate matter, 500 tons of carbon monoxide and 19 tons of formaldehyde. By its count, that would likely make it the largest industrial source of nitrogen oxides in the 11-county Memphis metro area. The suit asks the court to stop turbine operation without permits, require the best available pollution controls and impose daily penalties.

It is not the first time. At xAI’s first Memphis site, Colossus 1, the company originally ran 35 turbines without permits, according to SELC, and later received permits for 15.