Air Plan Approval; Michigan; Revisions to Part 9 Miscellaneous Rules

The Environmental Protection Agency (EPA) is proposing to approve a request submitted by the Michigan Department of Environmental Quality (MDEQ) on February 2, 2017, and supplemented on November 8, 2017, to revise the Michigan state implementation plan (SIP) for carbon monoxide (CO). The revision incorporates changes to Michigan's Air Pollution Control Rules entitled ``Emissions Limitations and Prohibitions--Miscellaneous.'' The revision updates existing source- specific rule requirements for ferrous cupola operations by removing obsolete rule language and makes a minor change to correct the citation to a Federal test method. The revision continues to result in attainment of the CO national ambient air quality standard (NAAQS).