AIBRIEF
Feds would no longer require public notice before state and local agencies approve 'minor source' air permits, a paperwork category that includes most data center backup generators and gas turbines.
EPA closed the public-comment window Thursday on a proposed rule that would drop the federal requirement for state and local air agencies to publish notice and hold a 30-day comment period before approving "minor source" air permits (The Register). EPA is now in post-comment review, and the docket (EPA-HQ-OAR-2025-1212) starts to harden into final text (Federal Register).
"Minor source" is a permit label, not a measure of actual emissions. A data center can keep that label while running hundreds of backup generators and gas turbines, as long as reported emissions stay under thresholds (commonly less than 25 tons per year each for VOCs and NOx) via fuel limits and controls. Amazon Data Services' pending Pennsylvania DEP application for a Falls Township data center lists roughly 280 natural-gas generators and diesel backups, all permitted as "synthetic minor" (H2O Water Network). More than 4,000 residents signed a petition. The only reason a 30-day public comment window applies is the current federal rule the proposal would make optional.
EPA Administrator Lee Zeldin has framed the change as cutting "unnecessary and burdensome red tape" and leaving decisions to state and local authorities (regulations.gov docket). That shifts the public-notice duty to state environmental agency dockets, state public-comment windows, and local air boards, which vary widely in rules and capacity (Western Water summary of CRS R49057).
Data center pollution will not all go unannounced. The federal floor disappears, and the next polluting data center near a reader will be reviewed under whatever that state's process happens to be.