The Environmental Protection Agency (EPA) is taking final action to approve a revision to the San Diego County Air Pollution Control District's (SDCAPCD or ``District'') portion of the California State Implementation Plan (SIP). This revision concerns a negative declaration for the 2008 8-hour ozone National Ambient Air Quality Standards (NAAQS) in the ozone nonattainment area under the jurisdiction of the SDCAPCD and one volatile organic compound (VOC) rule covering transfer of organic compounds into mobile transport trucks.

The Environmental Protection Agency (EPA) is finalizing the approval of a revision to the North Carolina State Implementation Plan (SIP) submitted by the North Carolina Department of Environmental Quality (NCDEQ), Division of Air Quality, via a letter dated April 13, 2021, and received by EPA on April 14, 2021. This revision contains minor clarifying and typographical edits to North Carolina's nitrogen oxides (NO<INF>X</INF>) rule. EPA is approving these changes pursuant to the Clean Air Act (CAA or Act).

The Environmental Protection Agency (EPA) is taking final action to disapprove revisions to the Missouri State Implementation Plan (SIP) submitted by Missouri on March 7, 2019. In its submission, Missouri requested rescinding a regulation addressing sulfur compounds from the SIP and replacing it with a new regulation that establishes requirements for units emitting sulfur dioxide (SO<INF>2</INF>).

Pursuant to the Federal Clean Air Act (CAA or the Act), the Environmental Protection Agency (EPA) is approving the CAA section 111(d) state plan submitted by the State of Arkansas for sources subject to the Municipal Solid Waste (MSW) Landfills Emission Guidelines (EG). The Arkansas MSW landfills plan was submitted to fulfill the state's obligations under CAA section 111(d) to implement and enforce the requirements under the MSW Landfills EG. The EPA is approving the state plan and amending the agency regulations in accordance with the requirements of the CAA.