Summary:
The Environmental Protection Agency (EPA) is proposing to approve the State Implementation Plan (SIP) revision submitted by Michigan on December 20, 2022, and supplemented on February 21, 2023, December 14, 2023, and April 2, 2024, which amends a SIP submission previously submitted to EPA on May 31, 2016, and June 30, 2016, for attaining the 1-hour sulfur dioxide (SO<INF>2</INF>) primary national ambient air quality standard (NAAQS) for the Detroit SO<INF>2</INF> nonattainment area. This action supplements a prior action which found that Michigan had satisfied emission inventory and new source review (NSR) requirements for this area, but had not met requirements under the Clean Air Act (CAA) for the elements proposed to be approved here.