The NAACP's Clean Air Act lawsuit against Elon Musk's xAI will go forward. On Monday, Oct. 19, 2026, the U.S. District Court for the Northern District of Mississippi denied the U.S. Justice Department's motion to dismiss the case, which targets the gas turbines in Southaven, Mississippi, that power xAI's Colossus 2 data center, according to the court's opinion and the Southern Environmental Law Center (SELC), which represents the plaintiffs.

What the court decided

  • The U.S. can join the case. The court allowed the United States to intervene, but wrote that "[w]hat the United States can and cannot do after intervention, however, is another matter."
  • It can't end it alone. The order says there is "no 'fairly possible' interpretation of the Clean Air Act that would give the United States the right to unilaterally dismiss a citizen suit," and that the court "does not share the 'serious constitutional doubts'" the government raised, SELC quoted.
  • Appeal route blocked for now. SELC said the ruling came shortly after the Fifth Circuit denied the DOJ's request to pause the district court case, because the lower court had not yet ruled.

Bloomberg Law summarized the result as the Trump EPA being allowed to join the suit while failing to win dismissal.

What the lawsuit is about

The suit, filed in April, says xAI violated the Clean Air Act by running methane gas turbines at the Southaven site before it had an air permit, Memphis station Action News 5 reported. The Mississippi Department of Environmental Quality granted a permit for 27 gas-powered turbines in March. SELC says the plant can emit more than 5,000 tons of nitrogen oxides a year; that is the plaintiffs' estimate, not a court finding.

In arguing for dismissal, the DOJ wrote that ending the case "accords with federal policy, national security, and the public interest," and said the government uses Grok for national security and military work, Action News 5 reported.

What both sides said

"The court made clear today that the law applies to everyone, including the federal government," said Abre' Conner, the NAACP's director of environmental and climate justice. Earthjustice enforcement director Laura Thoms said the administration "has gone out of its way to shield" xAI. xAI, now part of SpaceX, had not commented in the sources we reviewed.

What it means for Tesla

Colossus is the compute behind Grok, and Musk has pitched shared AI infrastructure as a core reason to combine SpaceX and Tesla (see our merger committees story). A drawn-out pollution case adds legal risk to that power-hungry buildout. For how SpaceX's AI revenue is growing, see SpaceX's Q3 results.