On June 24, 2011 the Illinois Environmental Protection Agency (Illinois EPA) promulgated a set of rules which address Regional Haze (40 CFR 51.308) by revising the Illinois State Implementation Plan (IL SIP) under various sections of Title 35 Illinois Administrative Code (IAC) Part 225 (35 IAC 225). These rules were approved by the United States Environmental Protection Agency (USEPA) on July 6, 2012 with an effective date of August 6, 2012. The Illinois EPA again revised the IL SIP on June 23, 2016 and subsequently provided additional explanation on these revisions on January 9, 2017. The revised rules are named the Combined Pollutant Standards (CPS and also known as Part 225 rules).

The main purpose of 35 IAC 225 rules is to regulate emissions of Mercury from coal-fired electric generating units (EGUs) operating in the State of Illinois and provide alternative means of compliance with the Mercury standards. The primary intent of these revisions is to address the requirements in order to accommodate the conversion of certain EGUs to use fuels other than coal (e.g. natural gas, distillate fuel oil with sulfur content of < 15 parts per million (ppm)). As part of this proposed rulemaking the sections to be revised are:

  • 35 IAC 225.291 (Purpose);
  • 35 IAC 225.292 (Applicability);
  • 35 IAC 225.293 (Notice of Intent);
  • 35 IAC 225.295 (Emissions Standards for Nitrogen Oxides (NOx) and Sulbur Dioxide (SO2));
  • 35 IAC 225.296 (Control Technology Requirements for NOx, SO2, and Particulate Matter (PM) Emissions);
  • 35 IAC 225, Appendix A (Specified EGUs for Purposes of the CPS).

As the revisions meet all the application requirements of the Clean Air Act (CAA) and Regional Haze Rules, the USEPA has proposed to approve the IL SIP. All comments must be received by October 2, 2017.

What's Next for the 2008 Ozone NAAQS in Chicago?

The USEPA is currently evaluating non-attainment designations for the 2008 ozone National Ambient Air Quality Standards (NAAQS). If it is determined that the Chicago area fails to attain the 2008 ozone NAAQS (75 ppb) by July 2018 based on monitoring data from 2015 to 2017, USEPA may reclassify the Chicago area as "serious" non-attainment for the 2008 ozone NAAQS. The Chicago area is currently classified as "moderate" non-attainment. This reclassification may become effective as early as January 2019.

Be sure to keep an eye on the 3-year average monitoring data as the reclassification to "serious" non-attainment would result in the following changes:

  • Title V major source threshold will be 50 tons per year (tpy) for volatile organic matter (VOM) and NOx (currently the threshold is 100 tpy); and
  • New Source Review (NSR) major modification threshold will be 25 tpy, aggregated over 5-years (currently the threshold is 40 tpy).

Keep in mind that this change in attainment status could impact upcoming projects at your facility!