The Environmental Protection Agency (EPA) is approving a State Implementation Plan (SIP) revision submitted on August 22, 2013 by the Maryland Department of the Environment (MDE) on behalf of the State of Maryland. This revision pertains to Maryland's major nonattainment New Source Review (NSR) program, notably preconstruction permitting requirements for sources of fine particulate matter (PM<INF>2.5</INF>). This action is being taken under the Clean Air Act (CAA).