The Environmental Protection Agency (EPA) is approving revisions to the State Implementation Plans (SIP) for Florida, Georgia, the Jefferson County portion of Kentucky, Mississippi, North Carolina, and South Carolina. The SIP revisions incorporate changes to the definition of chemical process plants under the States' Prevention of Significant Deterioration (PSD) regulations. Consistent with an EPA regulation completed in 2007, EPA is approving the rules for Florida, Georgia, the Jefferson County portion of Kentucky, Mississippi, North Carolina, and South Carolina that modify the definition of chemical process plant to exclude ethanol manufacturing facilities that produce ethanol by natural fermentation processes. Approving these modified definitions clarifies that the PSD major source applicability threshold in the SIPs for these ethanol plants is 250 tons per year (tpy) (rather than 100 tpy) and removes the requirement to include fugitive emissions when determining if the source is major for PSD. EPA concludes that the changes to the state and local rules are approvable because the Agency believes that they are consistent with EPA regulations governing state PSD programs and will not interfere with any applicable requirement concerning attainment and reasonable further progress (as defined in section 171 of the Clean Air Act (CAA or Act)), or any other applicable requirement of the CAA.