Air Quality Designations for the 2010 Sulfur Dioxide (SO2

The Environmental Protection Agency (EPA) is withdrawing the designation of Unclassifiable for the Citrus County, Florida, area that the EPA originally promulgated on December 21, 2017, and is establishing a designation of Attainment/Unclassifiable for that area as part of promulgating initial air quality designations for certain areas in the United States (U.S.) for the 2010 sulfur dioxide (SO2) primary National Ambient Air Quality Standard (NAAQS). This action supplements our December 2017 action, which together comprise the third of four expected rounds of actions to designate areas of the U.S. for the 2010 SO2 NAAQS. This third round of designations is based on application of the EPA's nationwide analytical approach and technical analysis, including evaluation of monitoring data and air quality modeling, to determine the appropriate designation based on the weight of evidence for each area.