The Environmental Protection Agency (EPA) is taking final action to approve, through parallel processing, revisions to the Missouri State Implementation Plan (SIP) relating to the St. Louis area's vehicle Inspection and Maintenance (I/M) Program received on November 12, 2019, March 2, 2022, and May 24, 2022. In the submissions, Missouri requests the EPA's approval of revisions to a regulation and related plan that implement the St. Louis area's Inspection and Maintenance program called, Gateway Vehicle Inspection Program (GVIP).

The Environmental Protection Agency (EPA) is proposing approval of revisions to the Missouri State Implementation Plan (SIP) received on November 29, 2016, and March 7, 2019. The revision was 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.

The Environmental Protection Agency (EPA) is proposing to approve a State Implementation Plan (SIP) revision submitted by the State of Montana on March 25, 2020, addressing regional haze.

Pursuant to the Federal Clean Air Act (CAA or the Act), the Environmental Protection Agency (EPA) is approving a State Implementation Plan (SIP) revision from the New Mexico Environment Department (NMED) submitted on October 17, 2016, on behalf of the Albuquerque-Bernalillo County Air Quality Control Board (Air Board). The submittal is in response to the EPA's national SIP call on June 12, 2015, concerning excess emissions during periods of Startup, Shutdown, and Malfunction (SSM).