Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Philadelphia County Reasonably Available Control Technology Under the 1997 8-Hour Ozone National Ambient Air Quality Standards

The Environmental Protection Agency (EPA) is proposing to approve state implementation plan (SIP) revisions submitted by the Commonwealth of Pennsylvania. These revisions pertain to a demonstration that Philadelphia County (Philadelphia) meets the requirements for reasonably available control technology (RACT) of the Clean Air Act (CAA) for nitrogen oxides (NOX) and volatile organic compounds (VOC) as ozone precursors for the 1997 8-hour ozone national ambient air quality standards (NAAQS). In this rulemaking action, EPA is proposing to approve three separate SIP revisions addressing RACT under the 1997 8-hour ozone NAAQS for Philadelphia, including new or revised source-specific RACT determinations for fifteen major sources of NOX and/or VOC and certifications that certain previous source-specific RACT determinations for major sources of NOX and/or VOC continue to adequately represent RACT under the 1997 8-hour ozone NAAQS. EPA also proposes to convert the prior conditional approval of the Philadelphia RACT demonstration for the 1997 8-hour ozone NAAQS to full approval, as Pennsylvania has met the obligations associated with the conditional approval. EPA therefore proposes to find that Pennsylvania has met all applicable RACT requirements under the CAA for the 1997 8-hour ozone NAAQS for Philadelphia. This action is being taken under the CAA.