Justice Department appeals to enter, and end, the NAACP's pollution suit against xAI

The Justice Department has taken the NAACP’s Clean Air Act suit against xAI to a federal appeals court before the trial judge has ruled on anything. On September 18 it filed a notice of appeal to the Fifth Circuit, which opened case No. 26-60806. Three days later it asked the district court to stop all proceedings until that appeal is decided.

The suit, filed in April, says xAI and its affiliate MZX Tech ran gas turbines in Southaven, Mississippi, without air permits to power the Colossus 2 supercomputer in Memphis. The NAACP’s latest filing puts the plant at 59 turbines.

An appeal from an order that was never written

On June 15 the United States moved to intervene in the case and have it dismissed. It filed an amended motion on July 7, on behalf of EPA Administrator Lee Zeldin. The Clean Air Act lets the government intervene in a citizen suit “as a matter of right.” The motion goes further: it argues that the executive branch’s authority to enforce federal law means the government can end a citizen suit it opposes.

The motion’s case for doing so is national security. It cites a declaration from Cameron Stanley, the Pentagon’s chief digital and AI officer, that Grok is “one of only four proprietary state-of-the-art” AI models able to support national security work. During Operation Epic Fury, the motion says, Grok “enabled U.S. forces to deploy over 2,000 munitions to 2,000 distinct targets within 96 hours.”

Judge Debra M. Brown has not issued a written ruling on that motion. The government says she held three status conferences without letting it take part, and that at the last one, on August 24, she said she intends to deny both its motion and xAI’s own motion to dismiss and to hold a hearing in October on the NAACP’s request to shut the turbines down. The transcript of that conference is not yet public, so that account is the government’s.

The government asked for a written order by September 10. None came. Its notice of appeal treats the silence as a “constructive Order denying” its motion.

What each side wants now

The government argues the appeal strips the district court of power over the intervention question, and that a turbine hearing in the meantime would cause “serious harm to the United States.”

The NAACP opposed the pause on September 28. “As it stands, the United States has nothing to appeal and the Fifth Circuit has nothing to review,” its lawyers wrote. They said a stay would leave people living near the plant exposed to its pollution “with each passing day.” The filing says regulators issued ozone action alerts on 26 days through September 2026, against 10 in all of 2025.

The NAACP also said it does not object to the government taking part in some form, and suggested the judge could admit it as a defendant with limits. The government’s reply calls that an “about-face” meant to head off the appeal.

When the government first moved to intervene, Kym Meyer, litigation director at the Southern Environmental Law Center, which represents the NAACP alongside Earthjustice, said its “frivolous arguments fly in the face of decades of well-established legal precedent.”

Where the case stands

The hearing on the NAACP’s request for a preliminary injunction was set for August 24, then postponed on August 21 “until further notice.” As of October 12 the docket showed no new date, no ruling on the stay, and no ruling on the injunction, xAI’s motion to dismiss or the government’s motion. The last filing was the government’s reply on October 5.