An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Frequently Asked Questions: Final Rule: Withdrawal of Finding of Substantial Inadequacy for State Implementation Plan and of Call for North Carolina State Implementation Plan (SIP) Revision: Automatic Exemptions and Director’s Discretion Provisions

Region 4’s final action outlines an alternative interpretation regarding automatic exemption and director’s discretion provisions for SSM events for the North Carolina State Implementation Plan (SIP) that departs from the EPA’s policy on this subject that was outlined in EPA’s 2015 SSM SIP Call Action at 80 FR 33840. Consistent with the alternative interpretation, Region 4’s final action finds that provisions 15A N.C. Admin. Code 2D .0535(c) and 15A N.C. Admin. Code 2D .0535(g) in the North Carolina SIP are not substantially inadequate to meet Clean Air Act (CAA) requirements and, accordingly, withdraws the SIP Call for North Carolina that was issued as part of the 2015 SSM SIP Call Action with respect to those provisions. The Region 4 final action also approves a SIP revision submitted by North Carolina regarding nitrogen oxide (NOx) emissions from large internal combustion engines.

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.