Law360 (September 22, 2026, 3:24 PM EDT) -- Two environmental groups sued Vantage and VoltaGrid in Texas federal court, claiming the AI data center developers are exploiting fast-track permits reserved for minor polluters even though their projects would use as much power as about one-fifth of the homes in San Antonio.

Public Citizen and the Sierra Club said Monday in the Clean Air Act citizen enforcement lawsuit that the companies failed to make any progress in addressing possible violations of the law that the groups raised in a July notice of intent to sue.

"Communities should not have to suffer excessive amounts of air pollution from data centers and power plants that fail to follow the Clean Air Act," said Mary Greene, director of enforcement at the Environmental Integrity Project, which is serving as plaintiffs' counsel. "We're suing Vantage and VoltaGrid because industrial development at this scale requires public input and stringent permits that prioritize health and air quality over the unbridled race for an economic edge."

Public Citizen and the Sierra Club argue Vantage and VoltaGrid are exploiting Texas' fast-tracked permitting system reserved for projects that are minor sources of pollution. Such projects don't require the most comprehensive pollution controls or monitoring, and the public isn't able to comment on or object to the plans.

The groups argue two under-construction projects on San Antonio's west side — at 14270 Omicron Drive and 5207 Rogers Road — should instead be classified as major pollution sources subject to more scrutiny. The 405 megawatts of dedicated generation at the two campuses would use as much power as 101,250 homes, or about 20% of all the homes in San Antonio.

In addition, another 151 backup diesel generators can provide 455 megawatts of power in the event of an outage.

The environmental groups said Vantage struck a deal in late 2024 to obtain power from VoltaGrid after learning it was unlikely that it could connect its San Antonio project to the grid.

The groups claimed the two companies sought to mask the true emissions potential of the data center campuses by splitting the power generation capacity of each campus into two sources: a gas-fired power plant and a group of diesel backup generators. The maneuver allowed the companies to claim each data center campus qualified as a minor pollution source carrying fewer regulatory hurdles and no public review.

Public Citizen and the Sierra Club argue any construction or operation of the campuses amounts to a Clean Air Act violation because the projects failed to stand up to scrutiny reserved for major pollution sources.

Vantage and VoltaGrid did not immediately respond to messages seeking comment Tuesday.

Public Citizen and the Sierra Club are represented by Gabriel Clark-Leach and Kenneth J. Rumelt of the Environmental Integrity Project.

Counsel information for the defendants was not available.

The case is Public Citizen et al. v. Vantage Data Centers et al., case number 5:26-cv-6032, in the U.S. District Court for the Western District of Texas.

--Editing by Haylee Pearl.

For a reprint of this article, please contact reprints@law360.com.