Proposed Rule2026-07904
Utah; Uinta Basin; 2015 8-Hour Ozone National Ambient Air Quality Standard; Reconsideration and Repeal of Finding of Failure To Attain and Reclassification to a Moderate Nonattainment Area; Extension of the Attainment Date and Determination of Attainment by the Marginal Attainment Date
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
April 23, 2026
Issuing agencies
Environmental Protection Agency
Abstract
The U.S. Environmental Protection Agency (EPA or Agency) is proposing to repeal the December 16, 2024 final rule in which we denied a request by the State of Utah (State) and the Ute Indian Tribe of the Uintah and Ouray Reservation (Ute Indian Tribe or Tribe) for an extension of the attainment date for the Uinta Basin (UB), Utah Marginal nonattainment area (NAA) under the 2015 ozone National Ambient Air Quality Standard (NAAQS), determined that the area failed to attain the Clean Air Act (CAA) 2015 ozone NAAQS by the applicable Marginal attainment date of August 3, 2022, and reclassified the area by operation of law to a Moderate ozone NAA. The EPA is also reproposing to grant the second 1-year extension of the Marginal attainment date from August 3, 2022 to August 3, 2023 and to determine that the area attained the 2015 ozone NAAQS based on certified ozone monitoring data from 2020-2022. If we finalize this proposed action, the UB area would no longer be subject to the CAA requirements pertaining to reclassification upon failure to attain and therefore would remain classified as a Marginal NAA for the 2015 ozone NAAQS.
Full Text
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<title>Federal Register, Volume 91 Issue 78 (Thursday, April 23, 2026)</title>
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[Federal Register Volume 91, Number 78 (Thursday, April 23, 2026)]
[Proposed Rules]
[Pages 21753-21758]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-07904]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Parts 52 and 81
[EPA-R08-OAR-2024-0001; FRL-13312-01-R8]
Utah; Uinta Basin; 2015 8-Hour Ozone National Ambient Air Quality
Standard; Reconsideration and Repeal of Finding of Failure To Attain
and Reclassification to a Moderate Nonattainment Area; Extension of the
Attainment Date and Determination of Attainment by the Marginal
Attainment Date
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule; reconsideration of final rule.
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SUMMARY: The U.S. Environmental Protection Agency (EPA or Agency) is
proposing to repeal the December 16, 2024 final rule in which we denied
a request by the State of Utah (State) and
[[Page 21754]]
the Ute Indian Tribe of the Uintah and Ouray Reservation (Ute Indian
Tribe or Tribe) for an extension of the attainment date for the Uinta
Basin (UB), Utah Marginal nonattainment area (NAA) under the 2015 ozone
National Ambient Air Quality Standard (NAAQS), determined that the area
failed to attain the Clean Air Act (CAA) 2015 ozone NAAQS by the
applicable Marginal attainment date of August 3, 2022, and reclassified
the area by operation of law to a Moderate ozone NAA. The EPA is also
reproposing to grant the second 1-year extension of the Marginal
attainment date from August 3, 2022 to August 3, 2023 and to determine
that the area attained the 2015 ozone NAAQS based on certified ozone
monitoring data from 2020-2022. If we finalize this proposed action,
the UB area would no longer be subject to the CAA requirements
pertaining to reclassification upon failure to attain and therefore
would remain classified as a Marginal NAA for the 2015 ozone NAAQS.
DATES: Written comments must be received on or before May 26, 2026.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R08-
OAR-2024-0001 to the Federal Rulemaking Portal: <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
htttps://www.regulations.gov. 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 (i.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 <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.
Docket: All documents in the docket are listed in the <a href="https://www.regulations.gov">https://www.regulations.gov</a> index. Although listed in the index, some
information is not publicly available, e.g., 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
<a href="https://www.regulations.gov">https://www.regulations.gov</a>. Please email or call the person listed in
the FOR FURTHER INFORMATION CONTACT section if you need to make
alternative arrangements for access to the docket.
FOR FURTHER INFORMATION CONTACT: 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: <a href="/cdn-cgi/l/email-protection#482a3a2125252d3a66292529262c29082d3829662f273e"><span class="__cf_email__" data-cfemail="b8dacad1d5d5ddca96d9d5d9d6dcd9f8ddc8d996dfd7ce">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Organization of this document. Throughout this document the use of
``we,'' ``us,'' or ``our'' is intended to refer to the EPA. The
information in this preamble is organized as follows:
Table of Contents
I. Background
II. Legal Authority
III. Proposed Action
IV. Tribal Consultation
V. Statutory and Executive Order Reviews
I. Background
Ground-level ozone pollution is formed from the reaction of
volatile organic compounds (VOC) and nitrogen oxides (NO<INF>X</INF>)
in the presence of sunlight. These two pollutants, referred to as ozone
precursors, are emitted by many types of sources, including on-road and
non-road motor vehicles and engines, industrial facilities, and smaller
area sources such as lawn and garden equipment and paints. Scientific
evidence indicates that adverse public health effects occur following
exposure to ground-level ozone pollution.\1\ Exposure to ozone can harm
the respiratory system (the upper airways and lungs), can aggravate
asthma and other lung diseases, and is linked to premature death from
respiratory causes. People most at risk from breathing air containing
ozone include people with asthma, children, older adults, and people
who are active outdoors, especially outdoor workers.\2\
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\1\ 80 FR 65296 (October 26, 2015).
\2\ EPA Fact Sheet--Ozone and Health, available at <a href="https://www.epa.gov/sites/default/files/2016-04/documents/20151001healthfs.pdf">https://www.epa.gov/sites/default/files/2016-04/documents/20151001healthfs.pdf</a> and in the docket for this action.
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Under CAA section 109, the EPA promulgates NAAQS (or ``standards'')
for ``each air pollutant for which air quality criteria have been
issued. . . .'', such as ozone.\3\ The EPA has previously promulgated
NAAQS for ozone in 1979, 1997, and 2008.\4\ On October 26, 2015, the
EPA revised the NAAQS for ozone to establish new 8-hour standards.\5\
In that action, the EPA promulgated identical revised primary and
secondary ozone standards designed to protect public health and welfare
that specified an 8-hour ozone level of 0.070 parts per million
(ppm).\6\ Specifically, the standards require that the 3-year average
of the annual fourth highest daily maximum 8-hour average ozone
concentration (i.e., the design value (DV)) may not exceed 0.070
ppm.\7\ Further, while the ozone NAAQS is expressed in units of ppm,
ozone is also discussed in terms of parts per billion (ppb), with 0.001
ppm equaling 1 ppb.\8\
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\3\ 42 U.S.C. 7409.
\4\ 44 FR 8202 (February 8, 1979), 62 FR 38856 (July 18, 1997),
and 73 FR 16436 (March 27, 2008).
\5\ See footnote 1 in this document.
\6\ 40 CFR 50.19. Because the 2015 primary and secondary NAAQS
for ozone are identical, for convenience, the EPA refers to them in
the singular as ``the 2015 ozone NAAQS'' or as ``the standard.''
\7\ A design value 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 design value for the
2015 ozone NAAQS is the 3-year average of the annual fourth highest
daily maximum 8-hour average ozone concentration. The design value
is calculated for each air quality monitor in an area and the area's
design value is the highest design value among the individual
monitoring sites in the area. According to appendix U to 40 CFR part
50, ambient monitoring sites with a DV of 0.070 ppm or less must
meet minimum data completeness requirements in order to be
considered valid. These requirements are met for a 3-year period at
a site if daily maximum 8-hour average ozone concentrations are
available for at least 90% of the days within the ozone monitoring
season, on average, for the 3-year period, with a minimum of at
least 75% of the days within the ozone monitoring season in any 1-
year. Ozone monitoring seasons are defined for each State in
appendix D to 40 CFR part 58. DVs greater than 0.070 ppm are
considered to be valid regardless of the data completeness.
\8\ The data handling convention in 40 CFR part 50, appendix U
dictates that concentrations shall be reported in ``ppm'' to the
third decimal place, with additional digits to the right being
truncated. Thus, a computed 3-year average ozone concentration of
0.071 ppm is greater than 0.070 ppm and would exceed the standard,
but a design value of 0.0709 is truncated to 0.070 and attains the
2015 ozone NAAQS.
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Section 107(d) of the CAA provides that when the EPA promulgates a
new or revised NAAQS, the Agency must designate areas of the country as
nonattainment, attainment, or unclassifiable based on whether an 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.\9\ Subpart 2 of Part
D of Title I of the CAA governs the classification, state planning, and
emission control requirements for any
[[Page 21755]]
areas designated as nonattainment for a revised primary ozone NAAQS. In
particular, CAA section 181(a)(1) also requires the EPA to classify
each ozone NAA at the time of designation, based on the extent of the
ozone problem in the area (based on the area's DV).\10\ Classifications
for ozone NAAs range from Marginal to Extreme. CAA section 182 provides
the specific attainment planning requirements that apply to each ozone
NAA based on its classification.\11\ CAA section 182, as interpreted in
the EPA's implementation regulations at 40 Code of Federal Regulations
(CFR) 51.1308 through 51.1317, sets for air agencies to submit and
implement State Implementation Plan (SIP) revisions to satisfy the
applicable attainment planning elements. These provisions also
establish the timeframes by which NAAs must attain the 2015 ozone
NAAQS.
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\9\ 42 U.S.C. 7407(d).
\10\ 42 U.S.C. 7511(a)(1).
\11\ 42 U.S.C. 7511a.
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Effective on August 3, 2018, the EPA designated 51 areas throughout
the country, including the UB in Utah, as nonattainment for the 2015
ozone NAAQS.\12\ In a separate action, the EPA set classification
thresholds and attainment dates based on each NAAs ozone DV.\13\ The
EPA established the attainment date for Marginal, Moderate, and Serious
NAAs as 3 years, 6 years, and 9 years, respectively, from the effective
date of designations. Thus, the attainment date for the UB ozone NAA
was August 3, 2021, which was to be calculated using monitored ozone
data from 2018-2020.\14\ Applicable SIP requirements for Marginal ozone
NAAs are provided in table 1 of this document.\15\
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\12\ 83 FR 25776 (June 4, 2018).
\13\ 83 FR 10376 (March 9, 2018).
\14\ See footnote 12 in this document.
\15\ See, e.g., CAA sections 172(c) (42 U.S.C. 7502) and 182 (42
U.S.C. 7511a).
Table 1--Required SIP Elements for Marginal Nonattainment Areas Under
the 2015 Ozone NAAQS
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Marginal SIP elements CAA section
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Base year emissions inventory \1\.. [172(c)(3); 182(a)(1); 40 CFR
51.1315(b)].
Certified Nonattainment New Source [172(c)(5); 182(a)(4); 40 CFR
Review (NNSR) \2\. 51.1314].
Emissions Statement \2\............ [182(a)(3)(B)].
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\1\ See 86 FR 35405 (July 6, 201).
\2\ See 87 FR 24275 (April 25, 2022).
The UB ozone NAA, initially classified as Marginal for the 2015
ozone NAAQS, was granted a 1-year attainment date extension under CAA
section 181(a)(5) in October 2022 which was requested by both the State
and Tribe.\16\ This extended the attainment date from August 3, 2021 to
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 (i.e., December 31, 2021, in the case of the UB
Marginal NAA for the 2015 ozone NAAQS).
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\16\ See footnote 12 in this document. See also 87 FR 60897
(October 7, 2022).
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On March 29, 2022 and December 20, 2022, respectively, the State
and Tribe requested a second 1-year extension under CAA section
181(a)(5) of the Marginal attainment date which would have extended the
Marginal attainment date from August 3, 2022 to August 3, 2023. In
response to the State's and Tribe's requests, on April 10, 2024, the
EPA published a notice of proposed rulemaking, based on certified ozone
monitoring information through 2022, to grant the requests for a second
1-year Marginal attainment date extension and determine that the area
attained by the new attainment date.\17\ While the EPA concluded that
the area did not attain the 2015 ozone NAAQS by the Marginal area
attainment date of August 3, 2022, based on a final 2019-2021 DV of
0.078 ppm, and as required per CAA section 181(b)(2)(A), we did
conclude in both our April 10, 2024 proposal and December 16, 2024
final rule that the eligibility criteria for a state to request an
attainment date extension had been met, per 40 CFR 51.1307(a)(1).\18\
Namely, these criteria include submitting all Marginal area SIP
elements to the EPA and having certified ozone monitoring data for
specific years that are all at or below the CAA established thresholds.
This conclusion was based on a two-year average fourth highest daily
maximum 8-hour concentration of 0.069 ppm for the years 2020 and
2021.\19\ Additionally, certified data through December 31, 2022,
showed that the three-year average for 2020-2022 was 0.067 ppm, which
is attaining the 2015 ozone NAAQS (see table 2 of this document).
Further, Utah certified that they complied with all requirements and
commitments pertaining to this area in their approved implementation
plan and monitoring data completeness.\20\
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\17\ 89 FR 25223 (April 10, 2024).
\18\ 89 FR 101483 (December 16, 2024). See also EPA's Response
to Comments in the accompanying docket to the final rule.
\19\ To request a second 1-year extension, an area's 4th highest
daily maximum 8-hour value, averaged over both the original
attainment year and the first extension year, must be 0.070 ppm or
less (40 CFR 51.1307(a)(2)). As of July 18, 2022, the Uinta Basin
area's certified 2020 and 2021 ozone data show that the maximum two-
year average design value for 2020-2021 is 0.069 ppm. This is based
on 2020 and 2021 ozone values at the two key monitors in the region
(AQS Site 490472002 which had 4th highest daily maximum 8-hour value
for 2020 at 0.066 ppm, and Air Quality System (AQS) Site 490472003
which had 4th highest daily maximum 8-hour value for 2021 at 0.072
ppm, which averaged is 0.069 ppm).
\20\ See letter dated March 30, 2022, from UDEQ Executive
Director Kim Shelley to U.S. EPA Region 8 Regional Administrator KC
Becker.
Table 2--Ozone Monitoring Values for Duchesne and Uintah Counties, Utah
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4th Highest daily max (ppm) \21\
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County AQS site ID Average Average Average
2019 2020 2021 2020-2021 2019-2021 2022 2020-2022
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Max 4th Max 0.098 \A\ 0.066 0.072 \B\ 0.069 0.078 0.066 \C\ 0.067
Duchesne..................................... 490130002 0.087 0.063 0.072 ........... 0.074 0.066 0.067
Duchesne..................................... 490137011 0.079 0.064 0.069 ........... 0.070 0.066 0.066
Uintah....................................... 490471002 0.070 0.063 0.068 ........... 0.067 0.063 0.064
[[Page 21756]]
Uintah....................................... 490471004 0.065 0.063 0.068 ........... 0.065 0.063 0.064
Uintah....................................... 490472002 0.074 0.066 0.071 ........... 0.070 0.062 0.066
Uintah....................................... 490472003 0.098 0.065 0.072 ........... 0.078 0.064 0.067
Uintah....................................... 490477022 0.067 0.065 0.068 ........... 0.066 0.062 0.065
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\A\ Basis for 1st 1-year extension (CAA section 181(a)(5) and 40 CFR 51.1307(a)(1)).
\B\ Basis for 2nd 1-year extension (CAA section 181(a)(5) and 40 CFR 51.1307(a)(2)).
\C\ Basis for Determination of Attainment by the Attainment Date (DAAD) (181(b)(2)(A) of the CAA and 40 CFR 51.1303).
As part of the December 2024 rulemaking, the EPA held a public
comment period that closed on May 9, 2024. The EPA received comments
from nine commenters, with two in support and seven in opposition.\22\
Two themes dominated the opposing comments: high 2023 ozone values and
environmental justice (EJ) concerns. Consequently, on December 16,
2024, the EPA published a final rule in the Federal Register using its
discretionary authority under CAA section 181(a)(5) to deny the request
for a second 1-year extension and determined that the UB ozone NAA
failed to attain the 2015 ozone NAAQS by the August 3, 2022 attainment
date.\23\ As shown in table 2 of this document, two of the seven
regulatory monitors in this area had a 2019-2021 DV greater than the
standard of 0.070 ppm.\24\ For that reason, the EPA reclassified the
area to Moderate by operation of law with an effective date of January
15, 2025 and an attainment date of August 3, 2024, in the December 16,
2024 final rule. In that action, the EPA committed to addressing SIP
revision and implementation deadlines for the UB in a separate
rulemaking given the attainment date was in the past.
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\21\ See footnote 8 of this document for explanation regarding
truncation of ozone values.
\22\ See EPA's response to comments for 2024 final rule, <a href="https://www.regulations.gov/document/EPA-R08-OAR-2024-0001-0023">https://www.regulations.gov/document/EPA-R08-OAR-2024-0001-0023</a>.
\23\ 89 FR 101483 (December 16, 2024).
\24\ See footnote 7 of this document.
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Following publication of the 2024 final rule, the EPA received
requests for reconsideration from the State on February 14, 2025, the
Tribe on January 14, 2025, UPA on February 14, 2025, and the Utah
Congressional delegation on January 14, 2025.\25\ Petitions to review
the 2024 final rule were filed with the 10th Circuit Court of Appeals
by the State on January 22, 2025, the Tribe on February 14, 2025, UPA
on January 21, 2025, and Seven County Infrastructure Coalition on
January 30, 2025. On February 25, 2025, the EPA granted the petitions
for reconsideration and stated our intention to undergo a notice-and-
comment rulemaking.\26\ Petitioners also filed motions to stay the 2024
final rule. The EPA did not oppose the motions to stay the final rule.
On May 22, 2025, the 10th Circuit Court of Appeals granted the
Petitioners' stay pending the outcome of the administrative
reconsideration.\27\ The practical implication of the judicial stay is
that the UB ozone NAA is currently classified as Marginal as of the
date of this proposal. Petitions and related documents and
correspondence are included in the docket for this rule (see <a href="https://www.regulations.gov">https://www.regulations.gov</a>, Docket No. EPA-R08-OAR-2024-0001).
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\25\ See Utah v. EPA, No. 11152346 (25-9507) (10th Cir., January
22, 2025); Utah Petroleum Association v. EPA, No. 11152544 (25-9507)
(10th Cir., January 21, 2025); Ute Indian Tribe of the Uintah and
Ouray Reservation v. EPA, No. 11158988 (25-9525) (10th Cir.,
February 14, 2025); and Seven-County Infrastructure Coalition v.
EPA, No. 11155255 (25-9513) (10th Cir., January 30, 2025). Copies of
the petitions are provided in Docket ID No. EPA-R08-OAR-2024-0001.
\26\ Copies of EPA's responses granting the petitions are
provided in Docket ID No. EPA-R08-OAR-2024-0001.
\27\ See State of Utah, Utah Petroleum Association, Ute Indian
Tribe of the Uintah and Ouray Reservation, and Seven-County
Infrastructure Coalition v. U.S. Environmental Protection Agency,
No. 25-9507, 25-9508, 25-9513, 25-9525 (10th Cir. 2025).
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After reconsidering the December 2024 final rule, the EPA now finds
that Utah sufficiently met the statutory criteria for a second 1-year
attainment date extension and the Agency is no longer exercising its
discretion to deny the State's and Tribe's request, which would have
imposed additional obstacles that Congress did not specifically
require.
II. Legal Authority
The statutory authority for the actions in this proposed rule is
provided by the CAA, as amended (42 U.S.C. 7401, et seq.). Relevant
portions of the CAA include, but are not necessarily limited to, CAA
section 181. Additionally, the EPA has authority to reconsider and
revise, rescind, and repeal final actions to the extent permitted by
law so long as it offers a reasonable basis for doing so and considers
applicable reliance interests.\28\ CAA section 181(b)(2)(A) provides
that, within six months following the applicable attainment date, the
EPA must determine whether an ozone NAA attained the ozone standard
based on the area's DV as of that date. If an area fails to attain by
its attainment date and does not receive a 1-year attainment date
extension, CAA section 181(b)(2)(A) requires the EPA to determine that
an ozone NAA failed to attain the ozone standard by the applicable
attainment date, and requires the area to be reclassified by operation
of law to the higher of (1) the next higher classification; or (2) the
classification corresponding to its DV at the time of the
determination. Section 181(b)(2)(B) of the CAA requires the EPA to
publish the determination of failure to attain and accompanying
reclassification in the Federal Register no later than six months after
the attainment date, which was February 3, 2023, for the UB ozone NAA.
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\28\ See, e.g., FDA v. Wages & White Lion Invs., L.L.C., 604
U.S. 542, 567-68 (2025); FCC v. Fox Television Stations, Inc., 556
U.S. 502, 515 (2009) (referencing Motor Vehicle Mfrs. Ass'n v. State
Farm Mut. Auto. Ins. Co., 463 U.S. 29 (1983)) (an agency is free to
change a prior policy and ``need not demonstrate . . . that the
reasons for the new policy are better than the reasons for the old
one; it suffices that the new policy is permissible under the
statute, that there are good reasons for it, and that the agency
believes it to be better'').
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Per CAA section 181(a)(5), the EPA has discretion (``the
Administrator may'') to extend an area's applicable attainment date by
one additional year upon application by any state if the state meets
the two criteria under CAA section 181(a)(5). See also 40 CFR 51.1307.
This section is intended to provide flexibility where an area is close
to achieving attainment and can likely do so with additional time.
Rather than require an area to attain the NAAQS by a first extended
attainment date, the provision expressly allows for a maximum of two 1-
year extensions for a single area.
[[Page 21757]]
Under CAA section 181(a)(5), the first criterion is satisfied if a
state can demonstrate that it is in compliance with its approved SIP.
See Delaware Dept. of Nat. Resources and Envtl. Control v. EPA, 895
F.3d 90, 101 (D.C. Cir. 2018) (holding that the CAA requires only that
an applying state with jurisdiction over a NAA comply with the
requirements in its applicable SIP, not every requirement of the Act).
A state may meet this requirement by certifying its compliance, and in
the absence of such certification, the EPA may determine whether the
criterion has been met. See Delaware, 895 F.3d at 101-102.
The second criterion, as it applies to a second 1-year extension,
is that the area's fourth highest daily maximum 8-hour value, averaged
over both the original attainment year and the first extension year,
must be no greater than the level of that NAAQS. With respect to the
second criterion, for the 2015 ozone NAAQS the EPA has interpreted the
air quality criterion of CAA section 181(a)(5)(B) to mean that an
area's fourth highest daily maximum 8-hour value, averaged over both
the original attainment year and the first extension year, must be no
greater than 0.070 ppm.
III. Proposed Action
This action addresses the UB ozone NAA, which includes portions of
Duchesne and Uintah Counties in Utah. This notice-and-comment
rulemaking arises out of the EPA's February 25, 2025 granting of
petitions for reconsideration of the December 16, 2024 final rule
submitted by the State, Tribe, UPA, and Utah's Congressional
delegation. After reconsideration and review of additional technical
information available at the time of the 2024 action, the EPA is
proposing to repeal the December 16, 2024 final rule. That rule found
the UB ozone NAA failed to attain by August 3, 2022, and reclassified
the area as Moderate by operation of law. The repeal would retain the
area's Marginal nonattainment classification. Technical information
made available since the final action, including certified 2024 and
preliminary 2025 ozone monitoring data also supports the EPA's proposal
to retain the area's Marginal nonattainment classification.\29\
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\29\ Preliminary 2025 data indicated that a potential ozone
exceedance occurred at the Roosevelt monitor on April 21, 2025. This
event has been flagged in the EPA's Air Quality System (AQS) as a
potential stratospheric intrusion event.
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Table 3 of this document provides a summary of the data from the UB
ozone NAA relevant to the area demonstrating attainment by the Marginal
attainment date. While the 2019-2021 DV does not show attainment, the
two-year average of 2020-2021 qualifies the UB ozone NAA for a second
1-year attainment date extension.\30\ Thus, the EPA is also proposing
to grant the second 1-year extension from August 3, 2022, to August 3,
2023. Consequently, based on the 2020-2022 DV, the region did not
exceed 0.070 ppm, and the EPA is therefore also proposing to find that
the UB ozone NAA attained by the new attainment date of August 3, 2023.
The EPA requests comment on these proposed actions. See the DATES
section in this document for deadline to submit comments.
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\30\ See footnote 21 of this document.
\31\ The 1st through 4th highest 8-hour average ozone
concentrations at each monitor for each year can be found at EPA's
Outdoor Air Quality Data, Monitor Values Report, <a href="https://www.epa.gov/outdoor-air-quality-data/monitor-values-report">https://www.epa.gov/outdoor-air-quality-data/monitor-values-report</a>. These
are Air Data reports are produced from a direct query of the Air
Quality System (AQS) Data Mart. The data represent the best and most
recent information available to EPA from state agencies. However,
some values may be absent due to incomplete reporting, and some
values may change due to quality assurance activities. The AQS
database is updated by state, local, and Tribal organizations who
own and submit the data.
Table 3--Uinta Basin 2015 Ozone NAAQS Marginal Nonattainment Area Evaluation Summary \31\
----------------------------------------------------------------------------------------------------------------
Area failed
Area failed to attain
to attain 2015 NAAQS
2015 NAAQS but state
but state requested
requested 1- 2nd 1-year
year attainment 2015 NAAQS
attainment 2020-2021 average date attained by the
2018-2020 date 2019-2021 DV 4th highest daily extension 2020-2022 DV 2nd 1-year
(ppm) extension (ppm) maximum 8-hr based on (ppm) attainment date
based on average (ppm) average extension
the 2020 2020-2021
4th highest 4th highest
daily daily
maximum 8- maximum 8-
hr average hr average
<=0.070 ppm <=0.070 ppm
----------------------------------------------------------------------------------------------------------------
0.076 Yes 0.078 0.069 Yes 0.067 Yes
----------------------------------------------------------------------------------------------------------------
This proposed determination of attainment by the attainment date
would not constitute formal redesignation to attainment as provided for
under CAA section 107(d)(3). Redesignations to attainment require,
among other things, that the states responsible for ensuring attainment
and maintenance of the NAAQS have met the applicable requirements under
CAA section 110 and part D, and to submit to the EPA for approval a
maintenance plan to ensure continued attainment of the standard for 10
years following redesignation, as provided under CAA section 175A.
If the EPA takes final action determining that the UB ozone NAA
attained the 2015 ozone NAAQS by the revised attainment date of August
3, 2023, the UB will remain a Marginal NAA under the 2015 ozone NAAQS
and must continue to meet the planning requirements specified in CAA
section 182(a).
The EPA seeks comment on all aspects of the proposed actions
described in this preamble, including with respect to our statutory
authority to reconsider and repeal the December 16, 2024 final rule and
any changes in interpretation and policy relevant thereto. Because this
action would, if finalized, relieve certain obligations for the State
of Utah, we do not believe there are reasonable and cognizable reliance
interests that would be adversely impacted by finalizing this action as
proposed. Nevertheless, we seek comment on whether such reliance
interests exist and, if so, how the EPA should consider them in taking
any final action on this proposal.
IV. Tribal Consultation
In accordance with the EPA Policy on Consultation and Coordination
with Indian Tribes, the EPA offered an opportunity for consultation to
the Tribe prior to this proposed EPA action (see section V.G. of this
document).\32\
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\32\ See EPA Policy on Consultation and Coordination with Indian
Tribes, December 7, 2023, <a href="https://www.epa.gov/sites/default/files/2013-08/documents/cons-and-coord-with-indian-tribes-policy.pdf">https://www.epa.gov/sites/default/files/2013-08/documents/cons-and-coord-with-indian-tribes-policy.pdf</a>.
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V. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 13563: Improving Regulation and Regulatory Review
This action is not a significant regulatory action and was
therefore not submitted to the Office of Management and Budget (OMB)
for review.
[[Page 21758]]
B. Executive Order 14192: Unleashing Prosperity Through Deregulation
Executive Order 14192 does not apply because a determination of
attainment is an air quality designation which is exempted from review
under Executive Order 12866.
C. Paperwork Reduction Act (PRA)
This rule does not impose an information collection burden under
the PRA. This action does not contain any information collection
activities.
D. Regulatory Flexibility Act (RFA)
I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA (5
U.S.C. 601 et seq.). This action will not impose any requirements on
small entities. A CAA determination of attainment by the attainment
date, and reclassification of the UB ozone NAA, will not in and of
themselves create any new requirements beyond what is mandated by the
CAA. This action would not itself directly regulate any small entities.
E. Unfunded Mandates Reform Act (UMRA)
This action does not contain an unfunded mandate as described in
UMRA, 2 U.S.C. 1531-1538 and does not significantly or uniquely affect
small governments. The action implements mandates specifically and
explicitly set forth in the CAA without policy discretion by the EPA.
F. Executive Order 13132 Federalism
This action does not have federalism implications. It will not have
substantial direct effects on the states, on the relationship between
the national government and the states, or on the distribution of power
and responsibilities among the various levels of government. The
division of responsibility between the Federal government and the
states for purposes of implementing the NAAQS is established under the
CAA.
G. Executive Order 13175 Consultation and Coordination With Indian
Tribal Governments
Executive Order 13175 requires EPA to develop an accountable
process to ensure ``meaningful and timely input by Tribal officials in
the development of regulatory policies that have Tribal implications.''
This action has Tribal implications, because it proposes actions that
will affect the ozone classification of a large area of Indian country
within the Uintah and Ouray Reservation. However, it will neither
impose substantial direct compliance costs on federally recognized
Tribal governments, nor preempt Tribal law.
The EPA provided an opportunity for consultation with Tribal
officials early in this rulemaking under our Policy on Consultation and
Coordination with Indian Tribes. The goal is to ensure meaningful and
timely input. The Tribe may request consultation and/or submit comments
to the EPA at any point during the rulemaking process, including during
the public comment period.
H. Executive Order 13045 Protection of Children From Environmental
Health and Safety Risks
EPA interprets Executive Order 13045 as applying only to those
regulatory actions that concern environmental health or safety risks
that EPA has reason to believe may disproportionately affect children,
per the definition of ``covered regulatory action'' in section 2-202 of
the Executive Order. This action is not subject to Executive Order
13045 because it does not establish an environmental standard intended
to mitigate health or safety risks.
I. Executive Order 13211 Actions That Significantly Affect Energy
Supply, Distribution, or Use
This action is not subject to Executive Order 13211 because it is
not a significant regulatory action under Executive Order 12866.
J. National Technology Transfer and Advancement Act (NTTAA)
This rulemaking does not involve technical standards.
List of Subjects
40 CFR Part 52
Environmental protection, Air pollution control, Ammonia, Carbon
oxides, Incorporation by reference, Intergovernmental relations, Lead,
Nitrogen oxides, Ozone, Reporting and recordkeeping requirements,
Sulfur oxides, and Volatile organic compounds.
40 CFR Part 81
Environmental protection, Administrative practice and procedure,
Air pollution control, Intergovernmental relations, Nitrogen oxides,
Ozone, Reporting and recordkeeping requirements, Sulfur oxides, and
Volatile organic compounds.
Dated: April 14, 2026.
Cyrus M. Western,
Regional Administrator, Region 8.
[FR Doc. 2026-07904 Filed 4-22-26; 8:45 am]
BILLING CODE 6560-50-P
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