Approval and Promulgation of Air Quality Implementation Plans; District of Columbia, Maryland, Virginia; 1-Hour Ozone Attainment Plans, Rate-of-Progress Plans, Contingency Measures, Transportation Control Measures, VMT Offset, and 1990 Base Year Inventory

EPA is approving State Implementation Plan (SIP) revisions submitted by the District of Columbia (the District), the State of Maryland and the Commonwealth of Virginia. These revisions include the 1996-1999 and 1999-2005 rate-of-progress (ROP) plans, changes to the 1990 base year inventory, a contingency measures plan, certain transportation control measures (TCMs), and a demonstration that each SIP contains any necessary transportation control measures to offset any growth in emissions from growth in vehicle miles traveled (VMT) and to demonstrate ROP and attainment of the 1-hour national ambient air quality standard (NAAQS) for ozone. These revisions also include the District's and Virginia's attainment plan for the Washington, DC severe 1-hour ozone nonattainment area (the Washington area). The intended effect of this action with respect to the following SIP revisions, all of which were submitted to satisfy the SIP requirements of 1-hour ozone nonattainment areas classified as severe, is to: approve the District's, Maryland's and Virginia's modeling demonstration, which includes the analysis based upon photochemical grid modeling, that the Washington area will attain the 1-hour ozone NAAQS; approve the District's, Maryland's and Virginia's post-1996 ROP plans, 1990 base year inventory revisions, TCMs, VMT offset and contingency measures SIP revisions; approve the District's and Virginia's attainment plans for the Washington area; and, determine that Maryland's SIP for the Washington area contains adopted control measures and determine that these measures fully satisfy the emission reductions relevant to attainment of the 1-hour ozone NAAQS.