Approval and Promulgation of Implementation Plans; California State Implementation Plan Revision; Kern 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 Kern County Air Pollution Control District (KCAPCD), Rule 424 and Yolo- Solano Air Quality Management District, Rule 2.37. The revisions include rescission and removal of an obsolete rule from the SIP and the incorporation of two rules into the Federally approved SIP. The rule to be removed regulated sulfur compound emissions from oil field steam generators. No units covered by this rule remain or are in operation within KCAPCD's jurisdictional area. The rules to be incorporated control emissions of oxides of nitrogen (NO<INF>X</INF>) from natural gas-fired residential water heaters. This approval action will incorporate the two rules into the Federally approved SIP. The intended effect of approving the rules is to regulate NO<INF>X</INF> emissions in accordance with the requirements of the Clean Air Act, as amended in 1990 (CAA or the Act). Thus, EPA is finalizing the approval of this revision into the California SIP under provisions of the CAA regarding EPA actions on SIP submittals, SIPs for national primary and secondary ambient air quality standards (NAAQS), and plan requirements for nonattainment areas.