[Federal Register Volume 90, Number 236 (Thursday, December 11, 2025)]
[Rules and Regulations]
[Pages 57365-57367]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-22582]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R09-OAR-2025-1113; FRL-12927-02-R9]


Approval of Air Quality Implementation Plans; Arizona; Arizona 
Department of Environmental Quality; Stationary Source Permits; West 
Pinal County; PM10

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final action.

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SUMMARY: The Environmental Protection Agency (EPA) is taking final 
action to fully approve the Arizona Department of Environmental 
Quality's (ADEQ or ``State'') portion of the Arizona State 
Implementation Plan (SIP) under the Clean Air Act (CAA or ``the Act'') 
that addresses Nonattainment New Source Review (NNSR) permitting for 
precursor emissions from major stationary sources for purposes of the 
1987 PM10 National Ambient Air Quality Standards (NAAQS or 
standard) in the West Pinal PM10 nonattainment area.

DATES: This action is effective January 12, 2026.

ADDRESSES: The EPA has established a docket for this action under 
Docket ID No. EPA-R09-OAR-2025-1113. All documents in the docket are 
listed on the https://www.regulations.gov website. Although listed in 
the index, some information is not publicly available, e.g., 
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 https://www.regulations.gov, or please 
contact the person identified in the FOR FURTHER INFORMATION CONTACT 
section for additional availability information. If you need assistance 
in a language other than English or if you are a person with a 
disability who needs a reasonable accommodation at no cost to you, 
please contact the person identified in the FOR FURTHER INFORMATION 
CONTACT section.

FOR FURTHER INFORMATION CONTACT: Rebecca Newhouse, EPA Region IX, 75 
Hawthorne St., San Francisco, CA 94105; telephone number: (415) 972-
3936; email address: [email protected].

SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us'' and 
``our'' refer to the EPA.

Table of Contents

I. Proposed Action
II. Public Comment and EPA Response
III. EPA Action
IV. Statutory and Executive Order Reviews

I. Proposed Action

    On September 11, 2025 (90 FR 43980), the EPA proposed to fully 
approve ADEQ's NNSR permitting program for precursor emissions from 
major stationary sources for the 1987 PM10 NAAQS in the West 
Pinal PM10 nonattainment area because we determined that it 
fulfills the relevant CAA requirements.

[[Page 57366]]

    As described in our proposal, the EPA issued a final rule in 
November 2015, taking action on a comprehensive 2012 NSR SIP submittal 
from the ADEQ that constituted a major update to the ADEQ's NSR program 
(``2015 NSR action''). 80 FR 67319 (Nov. 2, 2015). The EPA's 2015 NSR 
action also included a separate limited approval of the ADEQ's NNSR 
program for PM10 only with respect to the West Pinal 
PM10 nonattainment area, based on the requirements of 
section 189(e) of the Act, without an accompanying limited disapproval. 
80 FR 67319, 67332; see also 80 FR 14044, 14058, 14060 (Mar. 18, 2015) 
(proposed rulemaking for the 2015 NSR action). In the proposal for that 
action, the EPA observed that while the 2015 NSR action was generally 
SIP strengthening, CAA section 189(e) requires that the ADEQ's NNSR 
program for PM10 nonattainment areas apply to major 
stationary sources of PM10 precursors unless the EPA 
determines that such sources do not contribute significantly to 
PM10 levels which exceed the standard in the area. The NSR 
program did not apply to all precursors, and at that time, the EPA did 
not have the state's PM10 precursor analysis before us, and 
we could therefore not fully approve the 2012 NSR SIP submittal as 
complying with the CAA. 80 FR 14044, 14058.
    On December 15, 2023, the ADEQ submitted the ``2023 Five Percent 
Particulate Plan for PM-10 for the West Pinal County Nonattainment 
Area'' (``2023 PM10 Plan'') as a revision to the Arizona 
SIP, which includes a discussion of PM10 formation in the 
West Pinal PM10 nonattainment area and summarizes the 
State's PM10 precursor evaluation and determination that 
precursors do not contribute significantly to PM10 levels 
that exceed the NAAQS in the West Pinal PM10 nonattainment 
area. The EPA evaluated the State's PM10 precursor 
determination and concurred with the State's evaluation. Our proposal 
and TSD provide a more detailed discussion of our analysis supporting 
this determination.

II. Public Comments and EPA Responses

    The EPA's proposed action provided a 30-day public comment period. 
During this period, we received one comment.\1\
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    \1\ The comment was received on October 14, 2025, from a member 
of the public, and is available at www.regulations.gov under docket 
number EPA-R09-OAR-2025-1113.
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    The commenter stated, ``I believe the proposal should not be 
approved, because public health surveys were not conducted.'' The 
commenter stated that while the evidence in the State's PM10 
precursor analysis ``seems substantial,'' a survey of citizens within 
the nonattainment area to address health concerns related to PM 
pollution should be conducted to allow citizens within the 
nonattainment area to express their concerns. The commenter noted that 
while the proposal was open to public comments, many citizens are not 
able to accurately express their concerns.
    The EPA acknowledges the commenter's concerns regarding health 
input from the public. This issue is outside the scope of the present 
rulemaking, and the EPA does not have the authority to compel such a 
survey in this context. In the SIP framework established under Title I 
of the CAA, heath impacts are evaluated in the process of setting the 
NAAQS. The states then choose how to regulate sources such that the 
NAAQS are attained. Section 109 of the CAA specifies that the primary 
NAAQS are set at a level ``requisite to protect the public health'' 
with ``an adequate margin of safety.'' The PM10 NAAQS at 
issue in this rulemaking was established in 1987 (52 FR 24634, July 1, 
1987), and has been evaluated and retained multiple times since then. 
See 71 FR 61144 (Oct. 17, 2006), 78 FR 3085 (Jan 15, 2013), 85 FR 82684 
(Dec. 18, 2020), 89 FR 16202 (Mar. 6, 2024). Once the NAAQS has been 
established and the states are tasked with regulating sources to ensure 
attainment of the NAAQS, states are generally not required to re-
evaluate the health impacts of NAAQS pollutants.
    Under section 110(k)(3) ``the Administrator shall approve'' a 
complete SIP submittal ``if it meets all of the applicable requirements 
of [the Act].'' As explained in our proposal and TSD, the applicable 
Clean Air Act requirement for the purposes of this action is the 
section 189(e) requirement that ``control requirements applicable under 
plans in effect under this part for major stationary sources of PM-10 
shall also apply to major stationary sources of PM-10 precursors, 
except where the Administrator determines that such sources do not 
contribute significantly to PM-10 levels which exceed the standard in 
the area.'' As outlined in the proposal and TSD, the EPA evaluated the 
State's precursor analysis and found their evidence and arguments 
sufficient to conclude that, for the purposes of NNSR permitting, 
precursors do not significantly contribute to PM10 formation 
in the West Pinal nonattainment area. The comment does not indicate 
that precursors contribute significantly to PM10 formation 
in West Pinal, and it is not clear how public survey information would 
assist in the EPA's section 189(e) determination regarding whether 
precursors contribute significantly to PM10 levels which 
exceed the standard in the area. Lastly, as noted by the commenter, all 
members of the public, including those in the West Pinal nonattainment 
area, were afforded the opportunity to comment on our proposal within 
the 30-day comment period. See CAA section 307(h). The public also had 
the opportunity to comment on the EPA's NAAQS evaluation actions. 
Although both the State and the EPA are free to conduct additional 
public engagement, the EPA may not condition its approval of a SIP 
submission on such additional public engagement.

III. EPA Action

    No comments were submitted that change our assessment as described 
in our proposed action. Therefore, as authorized in section 110(k)(3) 
of the Act, the EPA is approving the portion of the Arizona SIP under 
the Act that addresses NNSR permitting for precursor emissions from 
major stationary sources for purposes of the 1987 PM10 NAAQS 
in the West Pinal PM10 nonattainment area. As noted in our 
proposal, this resolves the issue that led the EPA to issue a limited 
approval in the 2015 NSR action, and this was the only remaining issue 
to be resolved regarding the full approvability of the ADEQ's NNSR 
program for PM10 in the West Pinal nonattainment area.

IV. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the Act and applicable 
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, the EPA's role is to approve state choices, 
provided that they meet the criteria of the Clean Air Act. Accordingly, 
this action merely approves state law as meeting Federal requirements 
and does not impose additional requirements beyond those imposed by 
state law. For that reason, this action:
     Is not a significant regulatory action subject to review 
by the Office of Management and Budget under Executive Order 12866 (58 
FR 51735, October 4, 1993);
     Is not subject to Executive Order 14192 (90 FR 9065, 
February 6, 2025) because SIP actions are exempt from review under 
Executive Order 12866;
     Does not impose an information collection burden under the 
provisions

[[Page 57367]]

of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not subject to Executive Order 13045 (62 FR 19885, 
April 23, 1997) because it approves a state program;
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001); and
     Is not subject to requirements of section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the CAA.
    In addition, the SIP is not approved to apply on any Indian 
reservation land or in any other area where the EPA or an Indian Tribe 
has demonstrated that a Tribe has jurisdiction. In those areas of 
Indian country, the action does not have Tribal implications and will 
not impose substantial direct costs on Tribal governments or preempt 
Tribal law as specified by Executive Order 13175 (65 FR 67249, November 
9, 2000).
    This action is subject to the Congressional Review Act, and the EPA 
will submit a rule report to each House of the Congress and to the 
Comptroller General of the United States. This action is not a ``major 
rule'' as defined by 5 U.S.C. 804(2).
    Under section 307(b)(1) of the Clean Air Act, petitions for 
judicial review of this action must be filed in the United States Court 
of Appeals for the appropriate circuit by February 9, 2026. Filing a 
petition for reconsideration by the Administrator of this final action 
does not affect the finality of this action for the purposes of 
judicial review, nor does it extend the time within which a petition 
for judicial review may be filed, and shall not postpone the 
effectiveness of such rule or action. This action may not be challenged 
later in proceedings to enforce its requirements. (See section 
307(b)(2).)

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Particulate matter, Reporting 
and recordkeeping requirements.

    Dated: November 27, 2025.
Michael Martucci,
Acting Regional Administrator, Region IX.
[FR Doc. 2025-22582 Filed 12-10-25; 8:45 am]
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