Approval and Promulgation of Air Quality Implementation Plans; Illinois; Indiana; Chicago and Evansville Nonattainment Areas; Determination of Attainment of the Fine Particle Standards

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EPA is determining that the Chicago-Gary-Lake County, Illinois-Indiana ("Chicago") and Evansville, Indiana nonattainment areas have attained the 1997 fine particle (PM 2.5 ) National Ambient Air Quality Standard (NAAQS). These determinations are based upon quality-assured and certified ambient air monitoring data that show that the areas have monitored attainment of the 1997 PM 2.5 NAAQS for the 2006 to 2008 monitoring period. Currently available preliminary data for 2009 are consistent with continued attainment of the standard. As a result of these determinations, the requirements for these areas to submit an attainment demonstration and associated reasonably available control measures (RACM), a reasonable further progress plan (RFP), contingency measures, and other State Implementation Plan (SIP) revisions related to attainment of the standard are suspended for so long as the areas continue to attain the 1997 PM 2.5 NAAQS.