Utah; Northern Wasatch Front; 2015 8-Hour Ozone Nonattainment Area Boundary Expansion and Applicability of Certain Clean Air Act Requirements

<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 81</CFR> <DEPDOC>[EPA-R08-OAR-2025-0001; FRL-12971-02-R8]</DEPDOC> <SUBJECT>Utah; Northern Wasatch Front; 2015 8-Hour Ozone Nonattainment Area Boundary Expansion and Applicability of Certain Clean Air Act Requirements</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Final rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> U.S. Environmental Protection Agency (EPA or Agency) is approving a request to expand the boundary for the Northern Wasatch Front (NWF) 2015 8-hour ozone national ambient air quality standard (NAAQS) (2015 ozone NAAQS) nonattainment area (NAA). The request was submitted by the State of Utah on February 27, 2023. The newly expanded portion of the NWF NAA will have the same classification as the original NWF NAA under the 2015 ozone NAAQS and all applicable Clean Air Act (CAA) requirements will become applicable to the newly designated portion upon the effective date of the final action. The EPA is taking this action pursuant to the CAA. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This rule is effective on February 5, 2026. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> The EPA has established a docket for this action under Docket ID No. EPA-R08-OAR-2025-0001. All documents in the docket are listed on the <E T="03">https://www.regulations.gov</E> website. Although listed in the index, some information is not publicly available, <E T="03">e.g.,</E> Confidential Business Information (CBI) 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 through <E T="03">https://www.regulations.gov,</E> or please contact the person identified in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section for additional availability information. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Amanda Brimmer, Air and Radiation Division, EPA, Region 8, Mailcode 8ARD-AQ-R, 1595 Wynkoop Street, Denver, Colorado 80202-1129, telephone number: (303) 312-6323, email address: <E T="03">brimmer.amanda@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document “we,” “us,” and “our” means the EPA. <HD SOURCE="HD1">I. Background</HD> The background for this action is discussed in detail in our September 25, 2025 proposal (90 FR 46128). In that document we proposed to approve Utah's boundary expansion request for the NWF 2015 ozone NAAQS NAA under section 107(d)(3)(D) of the CAA, submitted by the State on February 27, 2023, as well as establish a 12-month deadline for State Implementation Plan (SIP) revisions for certain required elements. We received four submittals from five commenters on our proposal and our responses to comments are below. <HD SOURCE="HD1">II. Response to Comments</HD> <E T="03">Comment 1:</E> One anonymous commenter opposed the action, stating that granting the boundary expansion will result in less protection from air pollution for citizens in Utah. <E T="03">Response 1:</E> The EPA disagrees with the commenter. The purpose of the action is to incorporate additional area into the NAA which includes additional sources that will be held to higher air pollution standards and requirements that all other sources in the same region are required to adhere to. The net benefit is expected to be a reduction in ozone precursors from the US Magnesium, Limited Liability Company (LLC) facility which is located within the NAA due to the finalization of this action. <E T="03">Comment 2:</E> Multiple commenters, including the State of Utah, the Utah Petroleum Association, and the Utah Mining Association, expressed support of the action, including support of the limited revisions of SIP elements and the proposed timeline for submittal. <E T="03">Response 2:</E> The EPA appreciates the State's and industry's support of this action. <E T="03">Comment 3:</E> One commenter claimed that the EPA applied “Administrative Procedure Act (APA) 553(b) good cause provisions” and did not accept public comment before finalizing the rule, resulting in the commenter petitioning the EPA in their comments to stay the effective date of the rule. <E T="03">Response 3:</E> The EPA disagrees with the commenter. This claim relies on commenter's mistaken belief that the EPA issued a final rule with the September 25, 2025 action. The EPA published a notice of proposed rulemaking on September 25, 2025, not a final rule, which included a 30-day public comment period on the proposed rulemaking which closed on October 27, 2025. In this action we are finalizing the September 25, 2025 proposed action. Based on these facts, the proposed rule was not a final action for the commenter to petition the EPA for a stay or delay of a yet-to-be-established effective date. Finally, the EPA is not relying on APA 553(b) in this action. <E T="03">Comment 4:</E> One commenter erroneously claimed that the area was being reclassified from a Serious to a Severe nonattainment area, they stated that 30-50 facilities emitting between 25 and 49 tons per year (tpy) of ozone precursor emissions would become major sources as a result of this action, and argued that the EPA did not provide sufficient analysis on the impact to these small businesses within the NAA. <E T="03">Response 4:</E> The NWF ozone NAA is currently classified as Moderate, and the expanded portion of the NAA will have the same classification. The EPA is not proposing to reclassify the area to a higher classification in this rulemaking, thus the commenter's concern about Severe area SIP requirements becoming newly applicable is erroneous. This commenter also expressed concern about magnitude and types of small businesses that would newly become major sources. This is also incorrect as the major source threshold for Moderate NAAs, which the existing and new portion of the NAA will continue to be classified as, is 100 tpy. The EPA expects only one facility in the new portion of the NAA to be categorized as a major source, US Magnesium, LLC, which is discussed in the proposed rulemaking. <SU>1</SU> <FTREF/> The EPA acknowledges that some confusion may be due to a prior action for the NWF that reclassified the area to Serious, but that rule was stayed by the 10th Circuit Court of Appeals on April 30, 2025, and that rule is currently in abeyance while the EPA reconsiders the action, resulting in the NWF retaining its Moderate classification. <SU>2</SU> <FTREF/> <FTNT> <SU>1</SU>   <E T="03">See</E> 90 FR 46128 (Sept. 25, 2025). </FTNT> <FTNT> <SU>2</SU>   <E T="03">See</E> 89 FR 97545 (Dec. 9, 2024), and <E T="03">see</E> 10th Circuit Court of Appeals Decision granting stay motions and staying the Final Rule pending the outcome of these appeals, Appellate Case: 25-9519, dated Apr. 30, 2025. </FTNT> <E T="03">Comment 5:</E> One commenter accused the EPA of not adhering to the following statutory requirements: the Unfunded Mandates Reform Act (UMRA), the Regulatory Flexibility Act/Small Business Regulatory Enforcement Fairness Act (RFA/SBREFA), the Paperwork Reduction Act (PRA), and Executive Order (E.O.) 12866. <E T="03">Response 5:</E> With regard to the UMRA, the EPA has complied by making its own determination that this rule will not result in expenditures of $100M+, and therefore the Agency does not need to complete a statement under 2 U.S.C. 1532. The RFA and SBREFA are inapplicable to this rulemaking because the EPA has certified that this rule will not have a significant economic impact on a substantial number of small entities. The regulatory analysis provisions of the RFA are only triggered by a threshold determination by the Agency that this rule will have a significant economic impact on a substantial number of small entities. Because the Agency has certified this rule will not have a significant economic impact, section 603 and 604 of the RFA do not apply to this rulemaking. 5 U.S.C. 605(b). As discussed in Response 4, this rulemaking is only expected to incorporate one large source into the NAA, US Magnesium, LLC. The EPA has complied with the PRA by certifying in the rule that the PRA does not apply because the action does not involve an information collection burden as defined by the Act. <SU>3</SU> <FTREF/> Lastly, the Agency has complied with E.O. 12866 by determining that this rulemaking is not a significant regulatory action as defined in E.O. 12866. <FTNT> <SU>3</SU>   <E T="03">See</E> 44 U.S.C. 3502(2). </FTNT> <HD SOURCE="HD1">III. Final Action</HD> We are approving Utah's boundary expansion request for the NWF 2015 ozone NAAQS NAA under section 107(d)(3)(D) of the CAA. This action will expand the boundary of the existing NWF ozone NAA, adding 12 additional western townships in Tooele County. <SU>4</SU> <FTREF/> The NAA's current classification of Moderate and August 3, 2024 attainment date will apply to the entirety of the newly expanded NWF ozone NAA per 40 CFR 51.1303. <FTNT> <SU>4</SU>  Specifically, this will include Townships 1 North Range 6-8 West, Townships 2 North Range 6-8 West, Townships 3 North Range 7-8 West, and Townships 1-4 South Range 8 West. Further, EPA is correcting an error related to Township 4 South Range 7 West. This should read, “All sections within Township 4 South Range 7 West except for section 31”, as first divisions 29, 30, and 32 do not exist in this Township and first division 31 continues to be omitted from the NWF ozone NAA due to being Indian Country. </FTNT> As a result of being in nonattainment for ozone, a criteria pollutant, the CAA requires specific elements be developed and submitted to the EPA ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 25k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━