Approval and Promulgation of Air Quality Implementation Plans; Illinois; Missouri; Saint Louis Nonattainment Area; Determination of Attainment of the 1997 Annual Fine Particle Standard

The Environmental Protection Agency (EPA) is taking final action determining that the Saint Louis fine particle (PM<INF>2.5</INF>) nonattainment area in Illinois and Missouri has attained the 1997 annual PM<INF>2.5</INF> National Ambient Air Quality Standard (NAAQS). This final determination of attainment is based upon quality assured, quality controlled, and certified ambient air monitoring data for the 2007-2009 monitoring period which show that the Saint Louis area has monitored attainment of the 1997 annual PM<INF>2.5</INF> NAAQS, as well as quality assured data for 2010 that are in EPA's Air Quality System (AQS), but not yet certified, that show that the Saint Louis area has continued to monitor attainment of the 1997 annual PM<INF>2.5</INF> NAAQS. Pursuant to EPA's PM<INF>2.5</INF> implementation regulations, this final determination suspends the states' obligation to submit a number of plans for this area including: An attainment demonstration, associated reasonably available control measures (RACM), including reasonably available control technology (RACT), a reasonable further progress plan, contingency measures, and other planning State Implementation Plan (SIP) revisions related to attainment of the 1997 annual PM<INF>2.5</INF> NAAQS for so long as the area continues to attain the 1997 annual PM<INF>2.5</INF> NAAQS. EPA's determination that this area has attained the 1997 annual PM<INF>2.5</INF> NAAQS is not equivalent to redesignating the area to attainment. The designation of the area will remain nonattainment for the 1997 annual PM<INF>2.5</INF> NAAQS until such time as EPA determines that this area meets the Clean Air Act (CAA) requirements for redesignation to attainment.