Approval and Promulgation of Air Quality Implementation Plans; District of Columbia, Maryland, Virginia and Pennsylvania; Revised Carbon Monoxide Maintenance Plans for Washington Metropolitan, Baltimore and Philadelphia Areas

EPA is taking direct final action approving State Implementation Plan (SIP) revisions submitted by the District of Columbia, the State of Maryland, the Commonwealth of Virginia, and the Commonwealth of Pennsylvania that provide revised carbon monoxide (CO) maintenance plans and transportation conformity budgets for the Washington Metropolitan area, the Baltimore area, and the Philadelphia area. These plans provide for continued maintenance of the National Ambient Air Quality Standard (NAAQS) for CO. For the Washington Metropolitan area, the District of Columbia formally submitted its maintenance plan revision on March 9, 2004; the Maryland Department of the Environment formally submitted its revision on March 3, 2004, and the Commonwealth of Virginia submitted its revision on March 22, 2004. The Maryland Department of the Environment formally submitted its revision for the Baltimore area on July 15, 2004, previously having submitted a parallel processing request of the same name on December 18, 2003. The Pennsylvania Department of Environmental Protection formally submitted its revision for the Philadelphia area on September 3, 2004. In this action, EPA is approving the revised maintenance plans and revised transportation conformity budgets for each respective CO maintenance area. This action is being taken under section 110 of the Clean Air Act (CAA).