Pursuant to 40 CFR 51.102, the Department of Environmental Protection (DEP) announces a public hearing and opportunity to offer comments on a proposed revision to Florida’s State Implementation Plan (SIP) under the Clean Air Act. This proposed SIP revision consists of a request to redesignate the Hillsborough-Polk County sulfur dioxide (SO2) nonattainment area (NAA) and the Hillsborough-Polk County unclassifiable area (Mulberry Area) to attainment. This SIP submittal also includes the required CAA section 175A Maintenance plan for the Hillsborough-Polk County SO2 NAA, the CAA section 172(c)(3) emissions inventory and certification of the existing SIP-approved nonattainment new source review permitting program. This SIP submittal updates the modeling demonstration previously included in our December 1, 2017 source-specific SIP submittal requesting that EPA adopt into the Florida SIP the SO2 emission limits and compliance parameters for the Mosaic New Wales and Mosaic Bartow facilities. The Department is requesting that United States Environmental Protection Agency parallel process approval of this proposed SIP revision.