The Environmental Protection Agency (EPA) is approving multiple state implementation plan (SIP) revisions submitted by the Commonwealth of Pennsylvania. These revisions were submitted by the Pennsylvania Department of Environmental Protection (PADEP) to establish and require reasonably available control technology (RACT) for individual major sources of volatile organic compounds (VOC) and nitrogen oxides (NO<INF>X</INF>) pursuant to the Commonwealth of Pennsylvania's conditionally approved RACT regulations. In this action, EPA is only approving source-specific (also referred to as ``case-by- case'') RACT determinations for four major sources. These RACT evaluations were submitted to meet RACT requirements for the 1997 and 2008 8-hour ozone national ambient air quality standards (NAAQS). EPA is approving these revisions to the Pennsylvania SIP in accordance with the requirements of the Clean Air Act (CAA) and EPA's implementing regulations.