The Environmental Protection Agency (EPA) is approving amendments to the Mohegan Tribe of Indians of Connecticut (the Mohegan Tribe, Mohegans, or the Tribe) Tribal Implementation Plan (TIP) under the Clean Air Act (CAA) to regulate air pollution within the exterior boundaries of the Tribe's reservation. EPA approved the Tribe for treatment in the same manner as a State (Treatment as State or TAS) for purposes of administering New Source Review (NSR) under the CAA on December 26, 2006.

The Environmental Protection Agency (EPA) is approving a revision to the Idaho State Implementation Plan (SIP) submitted on May 4, 2022. The submission updates the incorporation by reference of the national ambient air quality standards and related planning and monitoring requirements into the Idaho air quality rules as of July 1, 2021. Idaho undertakes such updates regularly to ensure the state air quality rules and the federally enforceable Idaho SIP remain consistent with EPA air quality regulations over time.

The Environmental Protection Agency (EPA) is approving a revision to the Indiana particulate matter State Implementation Plan (SIP) that Indiana submitted to EPA on September 16, 2021, for the Vertellus Agriculture and Nutrition Specialties, LLC (Vertellus) facility located in Indianapolis, Marion County. Indiana requested revisions to incorporate site-specific updates to the particulate matter emission limits for Vertellus. The updates reflect revised emission rates for particulate matter resulting from process changes related to control strategies for other pollutants.

The Environmental Protection Agency (EPA) is taking final action to approve revisions to the Missouri State Implementation Plan (SIP) received on November 29, 2016, and March 7, 2019. The revisions were submitted by Missouri in response to a finding of substantial inadequacy and SIP call published on June 12, 2015, for a provision in the Missouri SIP related to excess emissions during startup, shutdown, and malfunction (SSM) events. In the submissions, Missouri requests to revise a regulation related to restriction of emissions of visible air contaminants.