Proposed rule · 2025-16325

Air Plan Revisions; California; Heavy-Duty Vehicle Inspection and Maintenance Program

The U.S. Environmental Protection Agency (EPA) is proposing to partially approve and partially disapprove or, in the alternative, to fully approve a submission by the State of California to revise its State Implementation Plan (SIP) relating to the control of emissions from non-gasoline combustion vehicles over 14,000 pounds. EPA is proposing to disapprove the State's "Heavy-Duty Inspection and Maintenance Regulation" to the extent it applies to vehicles registered out-of-state or out-of-country. The EPA has substantial concerns that the State has not provided adequate assurances under Clean Air Act (CAA) section 110(a)(2)(E)(i) that implementation of the SIP is not prohibited by Federal law. EPA seeks comment on this and other aspects of this proposed rule. If finalized as a partial approval and partial disapproval, this rule would allow certain aspects of the covered State regulations to go into effect and would not trigger CAA section 179 sanctions because the submittal is not a required submission under CAA section 110(a)(2). If finalized as an approval, this rule would allow all covered State regulations to go into effect.