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