Approval and Promulgation of Air Quality Implementation Plans; Ohio and Indiana; Redesignation of the Cincinnati-Hamilton Area to Attainment of the 1997 Annual Standard for Fine Particulate Matter

الملخص

EPA is proposing to approve Ohio's and Indiana's requests to redesignate their respective portions of the Cincinnati-Hamilton OH-IN- KY nonattainment area (for Ohio: Butler, Clermont, Hamilton, and Warren Counties, Ohio; for IN: a portion of Dearborn County) to attainment for the 1997 annual National Ambient Air Quality Standard (NAAQS or standard) for fine particulate matter (PM 2.5 ). The Ohio Environmental Protection Agency (Ohio EPA) submitted its request on December 9, 2010, and the Indiana Department of Environmental Management (IDEM) submitted its request on January 25, 2011. Kentucky's request to redesignate its portion of the Cincinnati- Hamilton area, submitted to EPA to on January 27, 2011, will be addressed in a separate rulemaking action. EPA's proposal here involves several additional related actions. EPA has previously determined that the entire Cincinnati-Hamilton (OH-IN-KY) area has attained the 1997 annual PM 2.5 standard. EPA is proposing to approve, as revisions to the Ohio and Indiana State Implementation Plans (SIPs), the States' plans for maintaining the 1997 annual PM 2.5 NAAQS through 2021 in the area. EPA is proposing to approve the 2005 emissions inventor