Approval and Promulgation of Implementation Plans; California State Implementation Plan Revision; San Diego County Air Pollution Control District; Yolo-Solano Air Quality Management District

EPA is taking direct final action to approve revisions to the California State Implementation Plan (SIP). The revisions concern rules from the following Districts: San Diego County Air Pollution Control District (SDCAPCD), and Yolo-Solano Air Quality Management District (YSAQMD). These revisions concern the control of oxides of nitrogen (NO<INF>X</INF>) from stationary gas turbine engines, industrial, institutional, and commercial boilers, steam generators, and process heaters. This approval action will incorporate these rules into the Federally approved SIP. The intended effect of approving these rules is to regulate emissions of NO<INF>X</INF> in accordance with the requirements of the Clean Air Act, as amended in 1990 (CAA or the Act). EPA is finalizing the approval of these revisions into the California SIP under provisions of the CAA regarding EPA action on SIP submittals, SIPs for national primary and secondary ambient air quality standards and plan requirements for nonattainment areas.