Pursuant to the Federal Clean Air Act (CAA or the Act), the Environmental Protection Agency (EPA) is approving revisions to the State Implementation Plan (SIP) for Oklahoma, submitted to the EPA by the State of Oklahoma designee (``the State'') on January 30, 2023. The SIP revisions being approved address amendments to subchapters regarding Control of Emission of Volatile Organic Compounds (VOCs) and Emission of Volatile Organic Compounds (VOCs) in Nonattainment Areas and Former Nonattainment Areas.

The Environmental Protection Agency (EPA) is taking final action to approve a revision to the San Diego County Air Pollution Control District (SDCAPCD) portion of the California State Implementation Plan (SIP). This revision concerns emissions of oxides of nitrogen (NO<INF>X</INF>) from small boilers, process heaters, steam generators, and large water heaters. We are approving a local rule that regulates these emission sources under the Clean Air Act (CAA or ``the Act'').

The Environmental Protection Agency (EPA) is approving revisions to the volatile organic compound (VOC) rules contained in the Indiana State Implementation Plan (SIP). The Indiana Department of Environmental Management (Indiana) modified its rules to allow the use of a VOC control device for cold cleaning degreasing operations as a compliance option to using low vapor pressure solvent for cleaning or degreasing machine parts. Rule language was also updated for clarity and consistency. EPA proposed to approve this action on August 30, 2023, and received no adverse comments.

The Environmental Protection Agency (EPA or ``Agency'') is taking final action to approve portions of state implementation plan (SIP) revisions submitted by the State of California to meet Clean Air Act (CAA or ``Act'') requirements for the 1997 annual fine particulate matter (PM<INF>2.5</INF>) national ambient air quality standards (NAAQS or ``standards'') in the San Joaquin Valley PM<INF>2.5</INF> nonattainment area.