The Environmental Protection Agency (EPA) is approving two State Implementation Plan (SIP) revisions, submitted by the State of Florida, through the Florida Department of Environmental Protection (FL DEP), to EPA on April 3, 2015, for the purpose of providing for attainment of the 2010 primary Sulfur Dioxide (SO<INF>2</INF>) National Ambient Air Quality Standard (NAAQS) in the Hillsborough County and Nassau County SO<INF>2</INF> nonattainment areas (hereafter referred to as the "Hillsborough Area," "Nassau Area," or "Areas"). The Hillsborough Area is comprised of the portion of Hillsborough County in Florida surrounding the Mosaic Fertilizer facility (hereafter referred to as "Mosaic"). The Nassau Area comprises the portion of Nassau County in Florida surrounding the Rayonier Performance Fibers, LLC sulfite pulp mill (hereafter referred to as "Rayonier"). EPA concludes that Florida has appropriately demonstrated that attainment with the 2010 1-hour primary SO<INF>2</INF> NAAQS will occur in the Nassau and Hillsborough Areas by the applicable attainment dates, and that the plans meet the other applicable requirements under the Clean Air Act (CAA or Act). As a part of approving the attainment demonstrations, EPA is taking final action to approve into the Florida SIP the SO<INF>2</INF> emissions limits and associated compliance parameters for both Areas.