Air Plan Approval; Minnesota and Michigan; Revision to Taconite Federal Implementation Plan

The Environmental Protection Agency (EPA) is proposing revisions to a 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 proposing to revise the nitrogen oxides (NOX) limits for taconite furnaces at facilities owned and operated by Cliffs Natural Resources (Cliffs) and ArcelorMittal USA LLC (ArcelorMittal). We are also proposing to revise the sulfur dioxide (SO2) requirements at two of Cliffs' facilities. We are proposing these changes because new information has come to light that was not available when we originally promulgated the FIP on February 6, 2013.