EPA is approving revisions to Chapter 74:36:09 of the South Dakota Administrative Rules (Prevention of Significant Deterioration) for incorporation into the South Dakota State Implementation Plan (SIP). South Dakota adopted these rule revisions on August 29, 2006 and May 14, 2007, and submitted the requests for approval to EPA on September 1, 2006 and June 28, 2007. One rule provision that EPA had proposed to disapprove has been corrected by South Dakota. Therefore, EPA is also approving that provision. South Dakota was granted delegation of authority by EPA on July 6, 1994, to implement and enforce the federal Prevention of Significant Deterioration (PSD) permitting regulations. As part of this final rule EPA is rescinding South Dakota's delegation of authority for implementing the federal PSD regulations. This action is being taken under section 110 of the Clean Air Act (CAA).