2015 8-hour Ozone 110(a) Infrastructure Certification

The final “Certification for Clean Air Act Section 110(a)(1) and (2) Infrastructure Requirements for the 2015 8-hour Ozone National Ambient Air Quality Standards (NAAQS)” was submitted to the United States Environmental Protection Agency (EPA) on September 27, 2018.

EPA revised the ground-level ozone 8-hour NAAQS on October 26, 2015 by lowering the primary (health-based) and secondary (welfare-based) standards to 0.070 parts per million (ppm), or 70 parts per billion (ppb) from the previous 0.075 ppm standard. All of North Carolina is attaining the standard and is designated by EPA as attainment/unclassifiable.

When EPA revises an existing standard, Clean Air Act (CAA) Sections 110(a)(1) and (2) require each state to revise their State Implementation Plan (SIP) to show they have the authority and programs needed to implement, maintain, and enforce the standard. This certification describes the basic program "infrastructure" elements that address the provisions of Section 110(a)(1) and (2) for the 2015 8-hour ozone NAAQS.

The transmittal letter, narrative, and attachments are available through the following links:

DEQ Submittal:

• Transmittal Letter (PDF)
• Certification (PDF)
• Attachment 1 EPA Memorandums and Notices (PDF)
• Attachments 2 and 3 - Clean Air Act Section 110(a)(2)(D)(i)(I) "Good Neighbor" Demonstration (PDF)
• Attachment 4 - Public Notice and EPA Comment Letter (PDF)

EPA Actions:

• Final Rule: Air Plan Approval; FL, GA, NC, SC; Interstate Transport (Prongs 1 and 2) for the 2015 8-Hour Ozone Standard (86 FR 68413, December 2, 2021)
• Proposed Rule Supplement: Air Plan Approval; FL, GA, NC, SC; Interstate Transport (Prongs 1 and 2) for the 2015 8-Hour Ozone Standard (86 FR 37942, July 19, 2021).
• Proposed Rule: Air Plan Approval; AL, FL, GA, NC, SC, TN; Interstate Transport (Prongs 1 and 2) for the 2015 8-Hour Ozone Standard (84 FR 71854, December 30, 2019)
• Proposed Rule: Air Plan Approval; NC; Miscellaneous NSR Revisions and Updates; Updates to References to Appendix W Modeling Guideline (includes Final Approval of 3 Prevention of Significant Deterioration Elements) (87 FR 61548, October 12, 2022)
• Final Rule: Air Plan Approvals; GA and NC: Prevention of Significant Deterioration Infrastructure Requirements for the 2015 Ozone NAAQS – Conditional Approval of 3 Elements (85 FR 20836, April 15, 2020)
• Proposed Rule: Air Plan Approvals; GA and NC: Prevention of Significant Deterioration Infrastructure Requirements for the 2015 Ozone NAAQS – Conditional Approval of 3 Elements (85 FR 7695, February 11, 2020)
• Final Rule: Air Plan Approval; GA and NC: Infrastructure Requirements for the 2015 8-Hour Ozone National Ambient Air Quality Standard (85 FR 14147, March 11, 2020)
• Proposed Rule: Air Plan Approval; GA and NC: Infrastructure Requirements for the 2015 8-Hour Ozone National Ambient Air Quality Standard (84 FR 71866, December 30, 2019)

Please direct any further questions or comments concerning this SIP submittal to the Planning Section Chief.