The Environmental Protection Agency (EPA) is taking direct final action to approve revisions to the Maryland State Implementation Plan (SIP). The revisions incorporate by reference (IBR) the current requirements of the Federal Prevention of Significant Deterioration (PSD) program into the Maryland SIP. Additionally, the revisions will allow Maryland's PSD program to automatically update with any revisions to the Federal regulations. EPA is approving these revisions to Maryland's PSD program in accordance with the requirements of the Clean Air Act (CAA).