Utah; Northern Wasatch Front; 2015 8-Hour Ozone Nonattainment Area Boundary Expansion and Applicability of Certain Clean Air Act Requirements

U.S. Environmental Protection Agency (EPA or Agency) is approving a request to expand the boundary for the Northern Wasatch Front (NWF) 2015 8-hour ozone national ambient air quality standard (NAAQS) (2015 ozone NAAQS) nonattainment area (NAA). The request was submitted by the State of Utah on February 27, 2023. The newly expanded portion of the NWF NAA will have the same classification as the original NWF NAA under the 2015 ozone NAAQS and all applicable Clean Air Act (CAA) requirements will become applicable to the newly designated portion upon the effective date of the final action. The EPA is taking this action pursuant to the CAA.