Air Plan Approval; Minnesota and Michigan; Revision to 2013 Taconite Federal Implementation Plan Establishing BART for Taconite Plants

The Environmental Protection Agency (EPA) is finalizing a revision to the Federal implementation plan (FIP) addressing the requirement for best available retrofit technology (BART) for taconite plants in Minnesota and Michigan. In response to petitions for reconsideration, we are revising the nitrogen oxides (NOX) limits for taconite furnaces at facilities owned and operated by Cliffs Natural Resources (Cliffs) and ArcelorMittal USA LLC (ArcelorMittal). Cliffs owns and operates Tilden Mining and United Taconite. Hibbing is owned by Cliffs, ArcelorMittal and U.S. Steel and operated by Cliffs. ArcelorMittal is owner and operator of Minorca Mine. We are also revising the sulfur dioxide (SO2) requirements at two of Cliffs' facilities. We are making these changes because new information has come to light that was not available when we originally promulgated the FIP on February 6, 2013.