Limited Maintenance Plan for the Great Smoky Mountains National Park, Rocky Mount, & Triangle Maintenance Areas for the 1997 8-Hour Ozone NAAQS

Final – September 22, 2020

On September 22, 2020, the Division of Air Quality (DAQ) submitted the final State Implementation Plan (SIP) revision for the “Limited Maintenance Plan (LMP) for the Great Smoky Mountains National Park (GSMNP), Rocky Mount, & Triangle Maintenance Areas for the 1997 8-Hour Ozone National Ambient Air Quality Standard (NAAQS)” for approval by the U.S. Environmental Protection Agency (EPA). The DAQ  prepared this LMP for the GSMNP, Rocky Mount, and Triangle maintenance areas for the 1997 8-hour ozone NAAQS to comply with the D.C. Circuit decision that vacated EPA’s interpretation that the second maintenance plans were not required for “orphan maintenance areas” (i.e., areas that had been redesignated to attainment for the 1997 ozone NAAQS (maintenance areas) and designated attainment for the 2008 ozone NAAQS) (South Coast, 882 F.3d 1138 (D.C. Cir. 2018)). The DAQ prepared the LMP following EPA guidance to fulfill the requirements of Clean Air Act Section 175A(b) with respect to the second maintenance plan period for each of the three areas. The LMP covers the last 10 years of the 20-year maintenance period for each area as follows:

  • GSMNP – January 7, 2020 through January 6, 2030
  • Rocky Mount – January 6, 2017 through January 5, 2027
  • Triangle – December 27, 2017 through December 26, 2027

DEQ Submittal:

EPA Actions:

  • Final Rule:  Air Plan Approval; NC; Great Smoky Mountains National Park, Raleigh-Durham-Chapel Hill and Rocky Mount Areas Limited Maintenance Plans for the 1997 8-Hour Ozone NAAQS (87 FR 27521, May 9, 2022)

  • Proposed Rule:  Air Plan Approval: NC; Great Smoky Mountains National Park, Raleigh-Durham-Chapel Hill and Rocky Mount Areas Limited Maintenance Plans for the 1997 8-Hour Ozone NAAQS (87 FR 7970, February 11, 2022)