The Environmental Protection Agency (EPA) is approving revisions to the Connecticut State Implementation Plan (leSIP) concerning ruits New Source Review (NSR) permit program. The Connecticut Department of Energy and Environmental Protection (CT DEEP) submitted these revisions on December 15, 2020, as well as a supplemental letter on February 14, 2023. The revised SIP incorporates various updates to CT DEEP's NSR procedural requirements, substantive review criteria, provisions related to the control of volatile organic compounds (VOCs), and clarifying revisions to existing SIP-approved regulations. EPA is also fully approving the state's infrastructure SIP for the 2015 National Ambient Air Quality Standards (NAAQS) ozone standard, which was previously conditionally approved.