EPA is approving revisions to the Minnesota State Implementation Plan (SIP) for sulfur dioxide (SO<INF>2</INF>). Specifically, the revisions involve Flint Hills Resources, L.P. (Flint Hills) of Dakota County, Minnesota. In these revisions, Flint Hills is expanding operations at its petroleum refinery. To account for the increased SO<INF>2</INF> emissions from the expansion, Flint Hills is closing its sulfuric acid plant. An analysis of the revisions shows that air quality in the area will be protected after the modifications are made at the facility. Minnesota has also included additional monitoring requirements in the revisions. EPA proposed approval of this revision on April 9, 2007. One comment was received on the proposed rule, but the comment did not involve the proposed revision. The comment is addressed in this action.