The Environmental Protection Agency (EPA) is approving a state implementation plan (SIP) revision submitted by the Commonwealth of Pennsylvania. This revision pertains to the Commonwealth's plan, submitted by the Pennsylvania Department of Environmental Protection (DEP), for maintaining the 1997 8-hour ozone national ambient air quality standard (NAAQS) (referred to as the ``1997 ozone NAAQS'') in the Franklin County, Pennsylvania area (Franklin County Area). EPA is approving these revisions to the Pennsylvania SIP in accordance with the requirements of the Clean Air Act (CAA).