Air Plan Approval; State of Utah; Utah PM2.5 State Implementation Plan Revisions

ENVIRONMENTAL PROTECTION AGENCY <SUBAGY>40 CFR Part 52</SUBAGY> <DEPDOC>[EPA-R08-OAR-2020-0098; FRL-12594-01-R8]</DEPDOC> <SUBJECT> Air Plan Approval; State of Utah; Utah PM <E T="0735">2.5</E> State Implementation Plan Revisions </SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Proposed rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The Environmental Protection Agency (EPA) is proposing to approve, through parallel processing, a State Implementation Plan (SIP) submission from the State of Utah with revisions to Utah Administrative Code (UAC), Utah State SIP, and the best available control measures/best available control technologies (BACM/BACT) determinations for five facilities found in the Salt Lake City, Utah nonattainment area (NAA) for the 2006 24-hour fine particulate matter with an aerodynamic diameter less than or equal to a nominal 2.5 microns (PM <E T="52">2.5</E> ) National Ambient Air Quality Standard (NAAQS) (State of Utah draft dated May 20, 2025). The EPA is taking this action pursuant to the Clean Air Act (CAA or the Act). </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Written comments must be received on or before August 15, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket ID No. EPA-R08-OAR-2020-0098, to the Federal Rulemaking Portal: <E T="03">https://www.regulations.gov.</E> Follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from <E T="03">https://www.regulations.gov.</E> The EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission ( <E T="03">i.e.,</E> on the web, cloud, or other file sharing system). For additional submission methods, the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit <E T="03">https://www.epa.gov/dockets/commenting-epa-dockets.</E> <E T="03">Docket:</E> All documents in the docket are listed in the <E T="03">https://www.regulations.gov</E> index. Although listed in the index, some information is not publicly available, <E T="03">e.g.,</E> CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, will be publicly available only in hard copy. Publicly available docket materials are available electronically in <E T="03">https://www.regulations.gov.</E> Please email or call the person listed in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> section if you need to make alternative arrangements for access to the docket. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Crystal Ostigaard, Air and Radiation Division, EPA, Region 8, Mailcode 8ARD-IO, 1595 Wynkoop Street, Denver, Colorado, 80202-1129, telephone number: (303) 312-6602, email address: <E T="03">ostigaard.crystal@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document wherever “we,” “us,” or “our” is used, we mean the EPA. <HD SOURCE="HD1">Table of Contents</HD> <EXTRACT> <FP SOURCE="FP-2">I. Background</FP> <FP SOURCE="FP-2">II. EPA's Evaluation of the May 20, 2025 Draft SIP Submission</FP> <FP SOURCE="FP-2">III. Proposed Action</FP> <FP SOURCE="FP-2">IV. Incorporation by Reference</FP> <FP SOURCE="FP-2">V. Statutory and Executive Order Reviews</FP> </EXTRACT> <HD SOURCE="HD1">I. Background</HD> <HD SOURCE="HD2"> A. Statutory and Regulatory Background for EPA's Regulation of PM <E T="0112">2.5</E> </HD> Under section 109 of the Act, the EPA has promulgated NAAQS for certain pollutants, including PM <E T="52">2.5</E> (40 CFR 50.2(b)). Once the EPA promulgates a NAAQS, section 107 of the Act specifies a process for the designation of each area within a state, generally as either an attainment area (an area attaining the NAAQS) or as a NAA (an area not attaining the NAAQS, or that contributes to nonattainment of the NAAQS in a nearby area). For PM <E T="52">2.5</E> , certain areas have also been designated “unclassifiable.” These various designations, in turn, trigger certain state planning requirements. For all areas, regardless of designation, section 110 of the Act requires that each state adopt and submit for EPA approval, a plan to provide for implementation, maintenance, and enforcement of the NAAQS. This plan is commonly referred to as a SIP. CAA section 110 contains requirements that a SIP must meet to gain EPA approval. <SU>1</SU> <FTREF/> For NAAs, SIPs must meet additional requirements in part D of title I of the Act. <FTNT> <SU>1</SU>  EPA's approval of a SIP has several consequences. For example, after the EPA approves a SIP, the EPA and citizens may enforce the SIP's requirements in federal court under section 113 and section 304 of the Act; in other words, the EPA's approval of a SIP makes the SIP “federally enforceable.” Also, once the EPA has approved a SIP, a state cannot unilaterally change the federally enforceable version of the SIP. Instead, the state must first submit a SIP revision to the EPA and gain EPA's approval of that revision. </FTNT> On October 17, 2006 (71 FR 61144), the EPA revised the level of the 24-hour PM <E T="52">2.5</E> NAAQS, lowering the primary and secondary standards from the 1997 standard of 65 micrograms per cubic meter (µg/m <SU>3</SU> ) to 35 µg/m <SU>3</SU> . On November 13, 2009 (74 FR 58688), the EPA designated three NAAs in Utah for the 2006 24-hour PM <E T="52">2.5</E> NAAQS of 35 µg/m <SU>3</SU> . These are the Salt Lake City; Provo; and Logan, Utah-Idaho  <SU>2</SU> <FTREF/> NAAs. <FTNT> <SU>2</SU>  The Logan, Utah-Idaho NAA was redesignated to attainment for the 2006 24-hour PM <E T="52">2.5</E> NAAQS on May 19, 2021 (86 FR 27035). </FTNT> The EPA originally issued a rule in 2007  <SU>3</SU> <FTREF/> regarding implementation of the 2006 24-hour PM <E T="52">2.5</E> NAAQS for the NAA plan requirements specified in CAA title I, part D, subpart 1. Under subpart 1, Utah was required to submit an attainment plan for each area no later than three years from the date of nonattainment designation. These plans needed to provide for the attainment of the PM <E T="52">2.5</E> standards as expeditiously as practicable, but no later than five years from the date the areas were designated nonattainment. <FTNT> <SU>3</SU>  72 FR 20586 (Apr. 25, 2007). </FTNT> In 2013, the U.S. Court of Appeals for the District of Columbia held that the EPA should have implemented the 2006 PM <E T="52">2.5</E> 24-hour standards, as well as the other PM <E T="52">2.5</E> NAAQS, based on both subpart 1 and subpart 4 of CAA title I, part D. <SU>4</SU> <FTREF/> Under subpart 4, all NAAs are initially classified as Moderate, and Moderate area attainment plans must address the requirements of subpart 4 as well as subpart 1. Additionally, subpart 4 sets a different SIP submittal due date and attainment year. For a Moderate area, the attainment SIP is due 18 months after designation and the attainment year is as expeditiously as practicable, but no later than the end of the sixth calendar year after designation. <FTNT> <SU>4</SU>   <E T="03">Nat. Res. Def. Council</E> v. <E T="03">EPA,</E> 706 F.3d 428, 437 (D.C. Cir. 2013) ( <E T="03">NRDC</E> ) or 2013 National Resources Defense Council (NRDC) decision. </FTNT> On June 2, 2014 (79 FR 31566), the EPA finalized the Identification of Nonattainment Classification and Deadlines for Submission of State Implementation Plan (SIP) Provisions for the 1997 Fine Particulate (PM <E T="52">2.5</E> ) National Ambient Air Quality Standard (NAAQS) and 2006 24-hour PM <E T="52">2.5</E> NAAQS. This rule classified the areas that were designated as Moderate in 2009 as nonattainment and set the attainment SIP submittal due date for those areas to December 31, 2014. Additionally, this rule established the Moderate area attainment date of December 31, 2015. On August 24, 2016 (81 FR 58010), the EPA finalized the Fine Particulate Matter National Ambient Air Quality Standards: State Implementation Plan Requirements (“PM <E T="52">2.5</E> Requirements Rule”), which partially addressed the 2013 National Resources Defense Council ( <E T="03">NRDC)</E> decision. The final PM <E T="52">2.5</E> Requirements Rule details how air agencies can meet the SIP requirements under subparts 1 and 4 that apply to areas designated nonattainment for any PM <E T="52">2.5</E> NAAQS, such as: general requirements for attainment plan due dates and attainment demonstrations; provisions for demonstrating reasonable further progress (RFP); quantitative milestones; contingency measures; nonattainment new source review (NNSR) permitting programs; and reasonable available control measures (RACM) (including reasonably available control technologies (RACT)). The statutory attainment planning requirements of subparts 1 and 4 were established to ensure that the following goals of the CAA are met: (i) that states implement measures that provide for attainment of the PM <E T="52">2.5</E> NAAQS as expeditiously as practicable; and (ii) that states adopt emissions reduction strategies that will be the most effective at reducing PM <E T="52">2.5</E> levels in NAAs. If an area is reclassified from Moderate to Serious, the area wi ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 47k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━