Air Plan Approval; North Carolina; Revisions to Regulations for Sulfur Dioxide Emissions From Combustion Sources

<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R04-OAR-2024-0163; FRL-12823-02-R4]</DEPDOC> <SUBJECT>Air Plan Approval; North Carolina; Revisions to Regulations for Sulfur Dioxide Emissions From Combustion Sources</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Environmental Protection Agency (EPA) is approving a State Implementation Plan (SIP) revision submitted by the North Carolina Division of Environmental Quality (NCDEQ), Division of Air Quality on November 28, 2023, for the purpose of revising regulations that establish sulfur dioxide (SO <E T="52">2</E> ) emission limits and compliance parameters for SO <E T="52">2</E> -emitting combustion sources in the State. EPA is approving these changes pursuant to the Clean Air Act (CAA or Act) and EPA regulations. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This rule is effective November 3, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> EPA has established a docket for this action under Docket Identification No. EPA-R04-OAR-2024-0163. All documents in the docket are listed on the <E T="03">regulations.gov</E> website. Although listed in the index, some information may not be publicly available, i.e., Confidential Business Information or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the internet and will be publicly available only in hard copy form. Publicly available docket materials are available either electronically through <E T="03">www.regulations.gov</E> or in hard copy at the Air Regulatory Management Section, Air Planning and Implementation Branch, Air and Radiation Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW, Atlanta, Georgia 30303-8960. EPA requests that if at all possible, you contact the person listed in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section to schedule your inspection. The Regional Office's official hours of business are Monday through Friday 8:30 a.m. to 4:30 p.m., excluding Federal holidays. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Matthew Bloemer, Multi Air Pollutant Coordination Section, Air Planning and Implementation Branch, Air and Radiation Division, Region 4, U.S. Environmental Protection Agency, 61 Forsyth Street SW, Atlanta, Georgia 30303-8960. The telephone number is (404) 562-9653. Mr. Bloemer can also be reached via electronic mail at <E T="03">Bloemer.Matthew@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> <HD SOURCE="HD1">I. This Action</HD> EPA is approving a SIP revision submitted by the NCDEQ, on November 28, 2023, that revises Rule 15A North Carolina Administrative Code (NCAC) 02D .0516, <E T="03">Sulfur Dioxide Emissions from Combustion Sources.</E> Rule 02D .0516 requires sources emitting SO <E T="52">2</E> through combustion and discharging through a vent, stack, or chimney to comply with an emission standard of 2.3 pounds per million British thermal unit (lbs/MMBtu). The Rule also provides criteria for how affected sources should determine compliance with the emission standard. North Carolina's November 28, 2023, SIP revision seeks to modify the Rule 02D .0516 applicability criteria respecting control devices and the provisions for determining compliance with the SO <E T="52">2</E> emission standard. More specifically, the SIP revision seeks to provide clarity and consistency with North Carolina's position that the use of supplemental fuels in combustion units beyond what is needed for proper operation is not a means for compliance with the SO <E T="52">2</E> emission standard at Rule 02D .0516. <HD SOURCE="HD1">II. Background</HD> Through a notice of proposed rulemaking (NPRM) published on August 14, 2025, (90 FR 39142), EPA proposed to approve North Carolina's November 28, 2023, SIP revision, changing Rule 02D .0516 to provide clarity and consistency with the State's position that the use of supplemental fuels in combustion units beyond what is needed for proper operation is not a means for compliance with the 2.3 lbs/MMBtu SO <E T="52">2</E> emission standard at Rule 02D .0516. The details of the North Carolina's submission and the rationale for EPA approving these changes are explained in the August 14, 2025, NPRM. Comments on the August 14, 2025, NPRM were due on or before September 15, 2025. EPA received three comments on the action: two in support and one potentially adverse. The comments are posted to the docket for this rulemaking. EPA summarizes and responds to the potentially adverse comment below. <HD SOURCE="HD1">III. Response to Comments</HD> EPA addresses the potentially adverse comment below. The commenter poses questions to EPA about EPA's proposed action. First, the commenter asks whether the SIP revision “meaningfully aligns with the latest climate science and the National Climate Assessment's projections for the Southeast, particularly regarding cumulative ozone and particulate matter exposures under increasing heat and wildfire events.” This comment is not relevant to this action on the North Carolina SIP. North Carolina's Rule 02D .0516 does not relate to wildfires, and the commenter does not provide any specificity about how their concerns with cumulative ozone and particulate matter in the Southeast relate to this SIP revision. As noted in the August 14, 2025, notice of proposed rulemaking (NPRM), the changes to North Carolina's SIP clarify and add to the existing emission limits and requirements regulating SO <E T="52">2</E> from fuel combustion sources, so there are no increases in emissions as a result of this change. Next, the commenter asks “[g]iven that environmental justice communities in the region often face disproportionate cumulative pollution burdens,” whether EPA will “require quantifiable distributional impact analysis to ensure the SIP does not perpetuate or exacerbate inequities in air quality outcomes.” This comment is not relevant to this action on the North Carolina SIP. No emissions will increase as a result of the changes to the SIP, and the commenter does not provide any information to indicate that there are any “inequalities in air quality outcomes” as a result of North Carolina's changes to Rule 02D .0516. The commenter goes on to ask how “the proposed revision [will] ensure enforceable emissions reductions from both stationary and mobile sources, with provisions to prevent backsliding if industrial activity increases or if economic growth outpaces existing control measures.” First, Rule 02D .0516 does not regulate mobile sources. Nor does the commenter provide any information to indicate that the SIP revision does not provide for enforceable emission reductions from stationary sources. As explained in the August 14, 2025, NPRM, the approved SIP regulates SO <E T="52">2</E> emissions from fuel combustion sources, and the SIP revision would help to provide clarity and consistency with the State's position that the use of supplemental fuel beyond what is needed for proper operation of a combustion unit is not a means for determining compliance with the SO <E T="52">2</E> emission limit. The commenter then asks whether EPA has “considered co-benefits of integrating stricter SIP measures with climate mitigation strategies—such as accelerating electrification of transport and industrial processes—to improve both public health and greenhouse gas reductions.” This comment is not relevant to this action on the North Carolina SIP. Next, the commenter asks “[w]hat mechanisms will be in place to guarantee transparent, publicly accessible monitoring data, particularly in rural and low-income areas where regulatory air quality sensors are sparse, but health vulnerabilities are often high.” This comment is not relevant to this action on the North Carolina SIP. Generally, state and local air agencies are required to maintain an ambient air monitoring network consistent with regulations in 40 CFR part 58, and the state and local agencies go through a public participation process in establishing their federally approved monitoring networks. The commenter then asks whether the SIP revision will “include adaptive management protocols to quickly respond to emerging air pollution sources, such as industrial expansions, port traffic increases, or climate-exacerbated wildfire smoke transport, without requiring multi-year procedural delays.” This comment is not relevant to the changes being made to North Carolina's SIP. Finally, the commenter asks whether “[c]onsidering the economic costs of air pollution-related health impacts” the “cost-benefit analysis incorporated updated public health valuation methods that capture the full societal benefits of stronger controls, especially for children, seniors, and outdoor workers.” This comment is not relevant to this action on the North Carolina SIP. There is no such cost-benefit analysis in the August 15, 2025, NPRM, and as noted therein, and above in this action, the changes to Rule 02D .0516 will not result in emissions increases. <HD SOURCE="HD1">IV. Incorporation by Reference</HD> In this document, EPA is finalizing regulatory text that includes incorporation by reference. In accordance with requirements of 1 CFR 51.5, and as discussed in Sections I and II of this preamble, EPA is finalizing the incorporation by reference of North Carolina Rule 15A NCAC 02D .0516, <E T="03">Sulfur Dioxide Emissions from Combustion Sources,</E> state effective June 1, 2023. EPA has made, and will continue to make, these materials generally available through <E T="03">www.regulations.gov</E> and at the EPA Region 4 Office (please contact the person identified in the <E T="02">For Further Inform ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 16k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━