On December 29, 2021, the Environmental Protection Agency (EPA or ``Agency'') published a proposed rule to approve the State of California's Serious area plan for the San Joaquin Valley (SJV) for the 2012 annual fine particulate matter (PM<INF>2.5</INF>) national ambient air quality standards (NAAQS) for all Serious PM<INF>2.5</INF> area planning requirements, except for contingency measures, which the EPA proposed to disapprove.

The Environmental Protection Agency (EPA) is approving a state implementation plan (SIP) revision submitted by the Commonwealth of Pennsylvania. The revision will fulfill Pennsylvania's nonattainment new source review (NNSR) SIP element requirement for the 2015 8-hour ozone national ambient air quality standard (NAAQS). EPA is approving these revisions to the Pennsylvania SIP in accordance with the requirements of the Clean Air Act (CAA).

The Environmental Protection Agency (EPA) is taking final action to withdraw the portion of a March 25, 2019 final action conditionally approving state implementation plan (SIP) submissions from the State of California under the Clean Air Act (CAA or ``Act'') to address contingency measure requirements for the 2008 ozone national ambient air quality standards (NAAQS or ``standards'') in the San Joaquin Valley, California ozone nonattainment area.

The Environmental Protection Agency (EPA) is finalizing approval of 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