Denial of Request for Attainment Date Extension, Finding of Failure To Attain, and Reclassification of an Area in Utah as Moderate for the 2015 Ozone National Ambient Air Quality Standards

<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 81</CFR> <DEPDOC>[EPA-R08-OAR-2024-0001; FRL-12469-01-R8]</DEPDOC> <SUBJECT>Denial of Request for Attainment Date Extension, Finding of Failure To Attain, and Reclassification of an Area in Utah as Moderate for the 2015 Ozone National Ambient Air Quality Standards</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 denying a request by the State of Utah and the Ute Indian Tribe for an extension of the attainment date for the Uinta Basin, Utah Marginal nonattainment area under the 2015 ozone National Ambient Air Quality Standards (NAAQS). In addition, we are determining that the area did not attain the standard by the applicable attainment date, and accordingly that the area will be reclassified by operation of law to “Moderate” nonattainment for the 2015 ozone NAAQS on the effective date of this final rule. With respect to the Uinta Basin area, this action fulfills the EPA's obligation under the Clean Air Act (CAA) to determine whether ozone nonattainment areas attained the NAAQS by the Marginal area attainment date and to publish a document in the <E T="04">Federal Register</E> identifying each area that is determined as having failed to attain and identifying the reclassification. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This rule is effective on January 15, 2025. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> EPA has established a docket for this action under Docket ID No. EPA-R08-OAR-2024-0001. 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 wherever “we,” “us,” or “our” is used, we mean the EPA. <HD SOURCE="HD1">I. Overview of Action</HD> The EPA is required to determine whether areas designated nonattainment for an ozone NAAQS attained the standard by the applicable attainment date, and to take certain steps for areas that failed to attain (see CAA section 181(b)(2)). The EPA's determination of attainment for the 2015 ozone NAAQS is based on a nonattainment area's design value (DV) as of the attainment date. <SU>1</SU> <FTREF/> <FTNT> <SU>1</SU>  A DV is a statistic used to compare data collected at an ambient air quality monitoring site to the applicable NAAQS to determine compliance with the standard. The data handling conventions for calculating DVs for the 2015 ozone NAAQS are specified in appendix U to 40 CFR part 50. The DV for the 2015 ozone NAAQS is the 3-year average of the annual fourth highest daily maximum 8-hour average ozone concentration. The DV is calculated for each air quality monitor in an area, and the DV for an area is the highest DV among the individual monitoring sites located in the area. </FTNT> The 2015 ozone NAAQS is met at a monitoring site when the DV does not exceed 0.070 parts per million (ppm). This action addresses the Uinta Basin area in Utah, which includes portions of Duchesne and Uintah Counties. The Uinta Basin was initially classified as Marginal for the 2015 ozone NAAQS and received a 1-year extension of the attainment date in 2022, making the Marginal area attainment date for this area August 3, 2022. As further explained in the Response to Comment document in the docket, in this action we are denying a request for a second 1-year extension. Accordingly, the applicable attainment date for the area remains August 3, 2022. Because DVs are based on the three most recent, complete calendar years of data preceding the attainment date, attainment must occur no later than December 31 of the year before the attainment date ( <E T="03">i.e.,</E> December 31, 2021, in the case of the Uinta Basin Marginal nonattainment area for the 2015 ozone NAAQS). Accordingly, the EPA's determination for this area is based upon the complete, quality-assured, and certified ozone monitoring data from calendar years 2019, 2020, and 2021. The EPA is finding that the Uinta Basin Marginal area did not attain by the attainment date, because the area's 2019-2021 DV was 0.078 ppm, which is greater than 0.070 ppm. Under CAA section 181(b)(2)(A), the effect of this determination is that this area will be reclassified by operation of law as Moderate on the effective date of this final rule. The reclassified area will then be subject to the Moderate area requirement to attain the 2015 ozone NAAQS as expeditiously as practicable, but not later than August 3, 2024. As a result of the area's reclassification as Moderate, Utah must submit to the EPA the State Implementation Plan (SIP) revisions for this area that satisfy the statutory and regulatory requirements applicable to Moderate areas established in CAA section 182(b) and in the 2015 Ozone NAAQS SIP Requirements Rule (see 83 FR 62998, December 6, 2018). The EPA will be establishing deadlines for the Uinta Basin area for submitting SIP revisions and for planning requirements on Indian Country in a separate action. <HD SOURCE="HD1">II. What is the background for this action?</HD> On October 26, 2015, the EPA issued its final action to revise the NAAQS for ozone to establish a new 8-hour standard ( <E T="03">see</E> 80 FR 65452, October 26, 2015). In that action, the EPA promulgated identical tighter primary and secondary ozone standards, designed to protect public health and welfare, that specified an 8-hour ozone level of 0.070 ppm. Specifically, the standards provide that the 3-year average of the annual fourth highest daily maximum 8-hour average ozone concentration may not exceed 0.070 ppm. Effective August 3, 2018, the EPA designated 52 areas throughout the country as nonattainment for the 2015 ozone NAAQS (see 83 FR 25776, June 4, 2018). In a separate action, the EPA assigned classification thresholds and attainment dates based on the severity of an area's ozone problem, determined by the area's DV (see 83 FR 10376, May 8, 2018). Consistent with CAA section 181(a), the EPA established the attainment date for Marginal, Moderate, and Serious nonattainment areas as 3 years, 6 years, and 9 years, respectively, from the effective date of the final designations. Thus, the attainment date for Marginal nonattainment areas for the 2015 ozone NAAQS was August 3, 2021; the attainment date for Moderate areas was August 3, 2024; and the attainment date for Serious areas is August 3, 2027. On October 7, 2022 (87 FR 60897), the EPA determined that 22 areas, including the Uinta Basin area, did not attain the standards by the Marginal attainment date. All of these areas except the Uinta Basin were reclassified as Moderate by operation of law. As to the Uinta Basin, however, EPA granted a 1-year extension of the attainment date, to August 3, 2022. The State of Utah requested a second 1-year extension of the attainment date for the Uinta Basin, to August 3, 2023. On December 20, 2022, the Ute Indian Tribe also requested a second one-year extension. <SU>2</SU> <FTREF/> Granting this extension would make the relevant years for evaluating attainment 2020-2022. On April 10, 2024 (89 FR 25223), EPA proposed to grant the request for a second extension, and to determine that the area attained by this attainment date based on data from 2020-2022. EPA took public comment on this proposal through May 10, 2024. <FTNT> <SU>2</SU>   <E T="03">See</E> letter dated December 20, 2022, from Ute Indian Tribe Chairman Shaun Chapoose to U.S. EPA Region 8 Regional Administrator KC Becker. </FTNT> <HD SOURCE="HD1">III. What is the statutory authority for this action?</HD> The statutory authority for this determination is provided by the CAA, as amended (42 U.S.C. 7401 <E T="03">et seq.</E> ), including sections 107, 181 and 182. CAA section 107(d) provides that when the EPA establishes or revises a NAAQS, the agency must designate areas of the country as nonattainment, attainment, or unclassifiable based on whether each area is not meeting (or is contributing to air quality in a nearby area that is not meeting) the NAAQS, meeting the NAAQS, or cannot be classified as meeting or not meeting the NAAQS, respectively. Subpart 2 of part D of title I of the CAA governs the classification, state planning, and emission control requirements for any areas designated as nonattainment for a revised primary ozone NAAQS. In particular, CAA section 181(a)(1) requires each area designated as nonattainment for a revised ozone NAAQS to be classified at the same time as the area is designated based on the extent of the ozone problem in the area (as determined based on the area's DV). Classifications for ozone nonattainment areas are “Marginal,” “Moderate,” “Serious,” “Severe,” and “Extreme,” in order of stringency. CAA section 182 provides the specific attainment planning and additional requirements that apply to each ozone nonattainment area based on its classification. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 47k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━