Revisions to the California State Implementation Plan, Northern Sierra Air Quality Management District

The Environmental Protection Agency (EPA) is taking direct final action to approve a revision to the Northern Sierra Air Quality Management District (NSAQMD or the District) portion of the California State Implementation Plan (SIP). The submitted SIP revision contains the District's demonstration regarding Reasonably Available Control Technology (RACT) requirements for the 1997 8-hour ozone National Ambient Air Quality Standards (NAAQS). The submitted SIP revision also contains negative declarations for volatile organic compound (VOC) source categories for the NSAQMD. We are approving the submitted SIP revision under the Clean Air Act as amended in 1990 (CAA or the Act).