Air Plan Approval; Illinois; National Ambient Air Quality Standards Updates; Reference and Equivalent Methods Updates
The Environmental Protection Agency (EPA) is approving several revisions to the Illinois State Implementation Plan (SIP). First, EPA is approving amendments to the Illinois SIP that incorporate by reference EPA's current national ambient air quality standard for ozone, particulate matter, lead, nitrogen dioxide, and sulfur oxides. Second, EPA is approving revisions to the Illinois SIP that incorporate by reference current Federal Reference Methods for monitoring carbon monoxide, ozone, particulate matter, lead, nitrogen dioxide, and sulfur oxides. Third, EPA is approving an amendment to the Illinois SIP that reflects a recent update to EPA's List of Designated Reference and Equivalent Methods. Lastly, EPA is approving minor revisions and corrections to the Illinois SIP.