The Illinois Environmental Protection Agency (IEPA) intends to request a re-designation of the Metro-East nonattainment area to attainment of the 1997 8-hour ozone standard based on ambient monitoring data from years 2007 through 2009.  (The Metro-East area includes the following counties:  Jersey, Madison, Monroe, and St. Clair.)  As part of the re-designation effort, IEPA has drafted a Maintenance Plan to address the state's program for maintaining the 8-hour ozone National Ambient Air Quality Standards (NAAQS).  IEPA will hold a public hearing to gather public comments on the draft Maintenance Plant.  The hearing will be held on April 8, 2010 at 10:30 AM.

You can read more about it at the following link:

http://www.epa.state.il.us/public-notices/2010/metro-east-ozone-sip/public-notice.pdf