Court lets US intervene, rejects bid to dismiss SpaceXAI pollution suit

A federal judge allowed the United States to intervene but denied its request to unilaterally dismiss a Clean Air Act citizen suit involving SpaceXAI’s data-center power operations in Mississippi. The October 19 ruling lets the government participate on behalf of the Environmental Protection Agency administrator while the plaintiffs’ case remains pending.

U.S. District Judge Debra M. Brown also left unresolved a separate dismissal motion filed by defendants X.AI Corp. and MZX Tech LLC. Her order required the United States to file a pleading that complies with Federal Rule of Civil Procedure 24© by October 23 if it wants to participate further in the case.

The split turns on the difference between joining a lawsuit and controlling another party’s claims. Brown found that the Clean Air Act gives the EPA administrator an unconditional right to intervene in a citizen suit. But she ruled that neither that provision nor Rule 41, which governs voluntary dismissals, authorizes the government to end a case brought by other plaintiffs over their objection. Rule 41 permits a plaintiff to dismiss its own action, the court said, but does not let one plaintiff dismiss another’s.

The court also pointed to a different Clean Air Act provision that can bar a citizen suit when the EPA or a state has begun and is diligently prosecuting a civil enforcement action requiring compliance. According to the opinion, the United States did not contend that the bar applied and had not filed such an enforcement action.

The government had asked to intervene and dismiss the suit, arguing in part that allowing it to proceed would interfere with executive enforcement authority. In its statement about the motion, the Justice Department also cited national-security and artificial-intelligence policy concerns. Brown rejected the proposed statutory reading and the constitutional-avoidance argument. Because the threshold issue was whether the United States had dismissal authority, the court did not evaluate the government’s policy reasons for seeking dismissal.

The complaint, filed by the NAACP and the Mississippi State Conference of the NAACP in April, alleges that X.AI and MZX Tech constructed and operated gas-fired turbines in Southaven without permits required by the Clean Air Act. The plaintiffs seek an injunction requiring compliance and pollution controls, civil penalties of up to $124,426 per day for each violation, and legal costs. Those permitting, emissions and health-impact assertions remain allegations: Brown’s October 19 opinion did not decide whether either defendant violated the law or award any of the requested relief.

The opinion said the defendants’ June 15 dismissal motion would be addressed in a separate order. That motion remained pending when Brown issued the October 19 ruling.