Approval and Promulgation of Air Quality Implementation Plans; District of Columbia, Virginia, Maryland; 1990 Base Year Emission Inventory for the Metropolitan Washington, DC Ozone Nonattainment Area

EPA is approving revisions to the District of Columbia (the District), the State of Maryland and the Commonwealth of Virginia State Implementation Plans (SIP) which pertain to the 1990 base year ozone emission inventory for the Washington, DC-MD-VA Consolidated Metropolitan Statistical Area (CMSA). This area, commonly referred to as the Metropolitan Washington, D.C. area, is classified as a serious ozone nonattainment area. These SIP revisions were prepared by the District, the Commonwealth of Virginia and the State of Maryland with the assistance of the Metropolitan Washington Council of Governments and were submitted for the purpose of revising the 1990 baseline of volatile organic compound (VOC) and nitrogen oxides (NOx) emissions that contribute to ozone nonattainment problems in the Metropolitan Washington, D.C. area. The intended effect of this action is to approve amendments to the 1990 base year ozone emission inventory for the Metropolitan Washington, D.C. area in accordance with the Clean Air Act.