USEPA is approving an August 19, 1999, request from Ohio for a State Implementation Plan (SIP) revision of the Columbiana County ozone maintenance plan. The maintenance plan revision establishes a new transportation conformity mobile source emissions budget for the year 2005. USEPA is approving the allocation of a portion of the safety margin for oxides of nitrogen (NO<INF>X</INF>) to the area's 2005 mobile source emissions budget for transportation conformity purposes. This allocation will still maintain the total emissions for the area at or below the attainment level required by the transportation conformity regulations. The transportation conformity budget for volatile organic compounds will remain the same as previously approved in the maintenance plan.