The Environmental Protection Agency (EPA) is approving most elements of a State Implementation Plan (SIP) submission from Minnesota regarding the infrastructure requirements of section 110 of the Clean Air Act (CAA) for the 2015 ozone National Ambient Air Quality Standards (NAAQS). The infrastructure requirements are designed to ensure that the structural components of each state's air quality management program are adequate to meet the state's responsibilities under the CAA. EPA proposed this action on May 24, 2022 and received no comments.

Pursuant to the Federal Clean Air Act (CAA or the Act), the Environmental Protection Agency (EPA) is approving revisions to the State Implementation Plan (SIP) for Oklahoma submitted by the State of Oklahoma designee with a letter dated May 7, 2020. The submittal covers updates to the Oklahoma SIP, as contained in the State's 2019 annual SIP update. Specifically, this action addresses revisions to Oklahoma Administrative Code (OAC) Title 252 Chapter 100 Subchapter 39, Emission of Volatile Organic Compounds (VOCs) in Nonattainment Areas and Former Nonattainment Areas.

This final rule includes corrections, clarifications, additional flexibilities, and adjustment factors to improve the Greenhouse gas Emissions Model (GEM) compliance tool for heavy-duty vehicles while more closely matching the outputs produced by the original GEM version 3.0 that was used to establish the CO<INF>2</INF> standards for Model Years 2021 and later in the 2016 Heavy-duty Phase 2 final rule. Given the nature of this rule, there will be neither significant environmental impacts nor significant economic impacts.

The Environmental Protection Agency (EPA) is proposing to approve a State Implementation Plan (SIP) revision submitted by the Commonwealth of Kentucky, through the Kentucky Energy and Environment Cabinet (Cabinet) on December 22, 2021, to address the base year emissions inventory requirements for the 2015 8-hour ozone national ambient air quality standard (NAAQS) for Kentucky counties in the Cincinnati, Ohio-Kentucky 2015 8-hour ozone NAAQS nonattainment area (hereinafter referred to as the Cincinnati, OH-KY Area), and for Kentucky counties in the Louisville, Kentucky-Indiana 2015 8-hour NA