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2010 SO2 110(a) Infrastructure Certification

Revision to Clean Air Act Section 110(a)(2)(D)(i)(I) "Good Neighbor" State Implementation Plan for the 2010 1-Hour Sulfur Dioxide Standard

The final Revision to North Carolina's 2010 1-Hour Sulfur Dioxide (SO2) Standard Infrastructure State Implementation Plan (SIP), Element 110(a)(2)(D)(i)(I), referred to as the "Good Neighbor" provision, was submitted to the United States Environmental Protection Agency (EPA) on June 16, 2016.

Through this submission, North Carolina is certifying that based on monitoring data, downward trend in statewide SO2 emissions, and the DAQ’s success with implementing the Data Requirements Rule for the 2010 1-hour SO2 primary NAAQS, emissions activities within North Carolina will not significantly contribute to nonattainment or interfere with maintenance of the 2010 1-hour SO2 NAAQS in a neighboring state.  This in large part is due to the significant strides North Carolina has achieved in reducing its SO2 emissions over the past several years.  Based on EPA’s guidance contained in the January 22, 2015 memorandum, states shown to not contribute significantly to downwind air quality problems have no emission reduction obligation under the Good Neighbor Provision.  The DAQ concludes that North Carolina has met its Section 110(a)(2)(D)(i)(I) requirements under the CAA with respect to the 2010 1-hour SO2 standard. 

The transmittal letter, certification and attachment are available through the following links:

DEQ Submittals:

Please direct any further questions or comments concerning this SIP submittal to Mr. Randy Strait at randy.strait@ncdenr.gov.

2010 SO2 110(a) Certification 

The final "North Carolina Certification for Clean Air Act Section 110(a)(1) and (a)(2) Infrastructure State Implementation Plan for the 2010 1-hour Sulfur Dioxide (SO2) standard" was submitted to the United States Environmental Protection Agency (USEPA) on March 18, 2014.

On June 22, 2010, the USEPA revised the National Ambient Air Quality Standards (NAAQS) for SO2. The USEPA adopted a new 1-hour standard of 75 parts per billion (ppb), measured as a three-year average of the annual 99th percentile of 1-hour daily maximum concentrations (40 CFR 50.17). The USEPA also revoked primary annual and 24-hour SO2 NAAQS.

On August 5, 2013, the USEPA promulgated nonattainment designations in locations where existing monitoring data from 2009-2011 indicated violations of the 1-hour SO2 standard (78 FR 47191). North Carolina has no violating monitors, but the USEPA indicated in its letter dated February 6, 2013 that it is deferring designations to a later date. The USEPA stated that "the agency is not yet prepared to issue designations in this final rule, and fully intends to address the designations for all other areas."

When the USEPA revises an existing standard, or as in the case of the 1-hour SO2 standard, promulgates a new standard, Clean Air Act Sections 110(a)(1) and (a)(2) require each state to revise their State Implementation Plan 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 (a)(2) for SO2. The transmittal letter and certification are available through the links found below:

DEQ Submittals:

EPA Actions:

  • Final Rule:  Air Plan Approval and Disapproval; North Carolina: New Source Review for Fine Particulate Matter (PM2.5).  Partially approve the PSD elements of sections 110(a)(2)(C), 110(a)(2)(D)(i)(II) (prong 3) and 110(a)(2)(J) and disapprove with respect to the PM2.5 increment requirements of 2010 PSD PM2.5 Rule. (81 FR 63107, September 14, 2016)
  • Proposed Rule:  Air Plan Approval and Disapproval; North Carolina: New Source Review for Fine Particulate Matter (PM2.5).  Partially approve the PSD elements of sections 110(a)(2)(C), 110(a)(2)(D)(i)(II) (prong 3) and 110(a)(2)(J) and disapprove with respect to the PM2.5 increment requirements of 2010 PSD PM2.5 Rule. (81 FR 28797, May 10, 2016)
  • Final Rule: Air Plan Approval; North Carolina; Visibility Infrastructure Requirements for CAA Section 110(a)(2)(d)(i)(II), prong #4 (81 FR 35634, June 3, 2016)
  • Proposed Rule:  Air Plan Approval; North Carolina; Visibility Infrastructure Requirements for CAA Section 110(a)(2)(d)(i)(II), prong #4 (81 FR 20600, April 8, 2016)
  • Final Rule:  Air Quality Plans; North Carolina; Infrastructure Requirements for the 2010 Sulfur Dioxide National Ambient Air Quality Standard for CAA Sections 110(a)(2)(A), (B), (C-except PSD permitting requirements for major sources), (D-ii), (F), (G), (H), (J-except PSD permitting requirements for major sources), (K), (L), and (M). (81 FR 24496, April 26, 2016)
  • Proposed Rule:  Air Quality Plans; North Carolina; Infrastructure Requirements for the 2010 Sulfur Dioxide National Ambient Air Quality Standard for CAA Sections 110(a)(2)(A), (B), (C-except PSD permitting requirements for major sources), (D-ii), (F), (G), (H), (J-except PSD permitting requirements for major sources), (K), (L), and (M). (81 FR 9398, February 25, 2016)
  • Final Rule:  Air Plan Approval; North Carolina; Conflict of Interest Infrastructure Requirements for CAA Section 110(a)(2)(E) (80 FR 67645, November 3, 2015)
  • Proposed Rule:  Air Plan Approval; North Carolina; Conflict of Interest Infrastructure Requirements for CAA Section 110(a)(2)(E) (FR 80 51167, August 24, 2015)

Please direct any further questions or comments concerning this certification submittal to Ms. Sushma Masemore at Sushma.Masemore@ncdenr.gov.

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