The Environmental Protection Agency (EPA) is approving rules submitted by the Wisconsin Department of Natural Resources (WDNR) as a revision to its State Implementation Plan (SIP). The submitted rules incorporate the 2015 primary and secondary National Ambient Air Quality Standards (NAAQS) for ozone. In addition, WDNR included several updates to ensure implementation of the ozone NAAQS, in areas currently or formerly designated as nonattainment for any ozone standard, in a manner consistent with Clean Air Act (CAA) requirements.

The Environmental Protection Agency (EPA) is proposing approval, and a limited approval and limited disapproval of a revision to the Antelope Valley Air Quality Management District (AVAQMD or ``District'') portion of the California State Implementation Plan (SIP). The EPA is proposing to take action on nine rules submitted on August 3, 2021. We are proposing approval of three rules, and limited approval and limited disapproval of six rules.

The Environmental Protection Agency (EPA) is proposing to approve revisions to the California State Implementation Plan (SIP) concerning the provisions for clean fuels or advanced control technology for boilers for the 2015 ozone national ambient air quality standards (``2015 ozone NAAQS'') in the San Joaquin Valley and Los Angeles--South Coast Air Basin, California (``South Coast'') ozone nonattainment areas.

The Environmental Protection Agency (EPA) is finalizing a program to further reduce air pollution, including ozone and particulate matter (PM), from heavy-duty engines and vehicles across the United States. The final program includes new emission standards that are significantly more stringent and that cover a wider range of heavy-duty engine operating conditions compared to today's standards; further, the final program requires these more stringent emissions standards to be met for a longer period of when these engines operate on the road.