EPA is approving a site specific revision to the Minnesota sulfur dioxide (SO<INF>2</INF>) State Implementation Plan (SIP) for the Rochester Public Utility's Cascade Creek Generating Facility (Cascade Creek), located in the city of Rochester, Olmsted County, Minnesota. On March 5, 2008, the Minnesota Pollution Control Agency (MPCA) requested that EPA approve certain portions of a joint Title I/Title V document into the Minnesota SO<INF>2</INF> SIP for the Cascade Creek facility. This SIP revision includes the addition of two new oil and gas fired turbines and modification of the starter engine on the No. 1 turbine. This SIP revision will show reduced emissions of SO<INF>2</INF> from this facility and the SO<INF>2</INF> National Ambient Air Quality Standards (NAAQS) will be maintained in the area. Because the SO<INF>2</INF> emission limits are being reduced, the air quality of Olmsted County will be protected.