The Environmental Protection Agency (EPA) is taking final action to partially approve and partially disapprove a revision to the Yolo-Solano Air Quality Management District (YSAQMD) portion of the California State Implementation Plan (SIP). The revision concerns the YSAQMD's demonstration regarding reasonably available control technology (RACT) requirements for the 2008 8-hour ozone National Ambient Air Quality Standards (NAAQS or ``standards'') in the portion of the Sacramento Metropolitan nonattainment area under the jurisdiction of the YSAQMD.