Air Plan Approval; Michigan and Wisconsin; Finding of Failure To Attain the 2010 Sulfur Dioxide Primary National Ambient Air Quality Standard for the Detroit and Rhinelander Nonattainment Areas

Resumo

The Environmental Protection Agency (EPA) is proposing to determine that the Detroit and Rhinelander sulfur dioxide (SO 2 ) nonattainment areas failed to attain the 2010 primary 1-hour SO 2 national ambient air quality standard (NAAQS or "standard") by the applicable attainment date of October 4, 2018. This proposed determination is based upon air quality modeling using actual and allowable emissions for the Detroit area and monitored air quality data from January 2015 to December 2017 for the Rhinelander area. If EPA finalizes these determinations as proposed, within one year after EPA publishes a final rule the States of Michigan and Wisconsin will be required to submit revisions to their State Implementation Plans (SIPs) that, among other elements, provide for expeditious attainment of the 2010 SO 2 standard. However, for the Rhinelander area, if EPA approves the recent revised SIP submission submitted by the State of Wisconsin, EPA is proposing to treat that submission as satisfying the requirement to submit revisions to the SIP to address the failure to timely attain the 2010 SO 2 NAAQS.