The EPA is approving State Implementation Plan (SIP) revisions to the sulfur dioxide (SO<INF>2</INF>) requirements for Flint Hills Resources, L.P. (Flint Hills) of Dakota County, Minnesota. Flint Hills operates a Rosemont, Minnesota petroleum refinery. The requested revisions will allow the refinery to produce ultra low sulfur diesel fuel. This expansion will add five sources and create an increase in sulfur dioxide emissions. An analysis of the additional sources was conducted. The results show that the air quality of Dakota County will remain in compliance of the National Ambient Air Quality Standards (NAAQS) for sulfur dioxide.