This action approves three State Implementation Plan (SIP) revisions for the State of Minnesota which were submitted on October 17, 1997. These SIP revisions modify Administrative Orders for North Star Steel Company and LaFarge Corporation (North Star Steel and LaFarge) located in St. Paul, Minnesota, and GAF Building Materials (GAF) located in Minneapolis, Minnesota. The Orders to these facilities are included as part of Minnesota's SIP to attain and maintain the National Ambient Air Quality Standards (NAAQS) for particulate matter (PM) and sulfur dioxide (SO<INF>2</INF>). In the proposed rules section of this Federal Register, the Environmental Protection Agency (EPA) is proposing approval of, and soliciting comments on, these SIP revisions. If adverse comments are received on this action, EPA will withdraw this final rule and address the comments received in response to this action in a final rule based on the related proposed rule, which is being published in the proposed rules section of this Federal Register. A second public comment period will not be held. Parties interested in commenting on this action should do so at this time.