Proposed Rule2026-21289
Air Quality Plan; Arizona; Agricultural Best Management Practices Rules for the West Pinal County PM10 Nonattainment Area
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
October 19, 2026
Issuing agencies
Environmental Protection Agency
Abstract
The U.S. Environmental Protection Agency (EPA) is proposing to approve a revision to the Arizona Department of Environmental Quality (ADEQ or "State") portion of the Arizona State Implementation Plan (SIP). This revision concerns emissions of particulate matter (PM) that are 10 micrometers ([mu]m) or smaller in diameter (PM<INF>10</INF>) from agricultural crop and animal operations in the West Pinal County PM<INF>10</INF> nonattainment area. We are proposing to approve two local rules to regulate these emission sources under the Clean Air Act (CAA or "Act").
Full Text
<html>
<head>
<title>Federal Register, Volume 91 Issue 200 (Monday, October 19, 2026)</title>
</head>
<body><pre>
[Federal Register Volume 91, Number 200 (Monday, October 19, 2026)]
[Proposed Rules]
[Pages 66040-66043]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-21289]
=======================================================================
-----------------------------------------------------------------------
ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R09-OAR-2024-0600; FRL-13422-01-R9]
Air Quality Plan; Arizona; Agricultural Best Management Practices
Rules for the West Pinal County PM10 Nonattainment Area
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
-----------------------------------------------------------------------
SUMMARY: The U.S. Environmental Protection Agency (EPA) is proposing to
approve a revision to the Arizona Department of Environmental Quality
(ADEQ or ``State'') portion of the Arizona State Implementation Plan
(SIP). This revision concerns emissions of particulate matter (PM) that
are 10 micrometers ([mu]m) or smaller in diameter (PM<INF>10</INF>)
from agricultural crop and animal operations in the West Pinal County
PM<INF>10</INF> nonattainment area. We are proposing to approve two
local rules to regulate these emission sources under the Clean Air Act
(CAA or ``Act'').
DATES: Comments must be received on or before November 18, 2026.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2024-0600 at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. For comments submitted at
<a href="http://Regulations.gov">Regulations.gov</a>, follow the online instructions for submitting
comments. Once submitted, comments cannot be edited or removed from
<a href="http://Regulations.gov">Regulations.gov</a>. 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, please contact the person identified in
the FOR FURTHER INFORMATION CONTACT section. For 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>. 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: Alina Batool, EPA Region IX, 75
Hawthorne St., San Francisco, CA 94105; telephone number: (415) 972-
3345; email address: <a href="/cdn-cgi/l/email-protection#2644475249494a08474a4f48476643564708414950"><span class="__cf_email__" data-cfemail="b5d7d4c1dadad99bd4d9dcdbd4f5d0c5d49bd2dac3">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us,''
and ``our'' refer to the EPA. We use multiple abbreviations and terms
in this proposed rule. While this list may not be exhaustive, for ease
of reading and for reference purposes, the EPA defines the following
terms and acronyms here:
AAC--Arizona Administrative Code
ADEQ--Arizona Department of Environmental Quality
AgBMP--agricultural best management practices
A.R.S.--Arizona Revised Statures
BACM--best available control measures
BMP--best management practices
CAA--Clean Air Act
CBI--confidential business information
CFR--Code of Federal Regulations
EPA--Environmental Protection Agency
NAAQS--national ambient air quality standards
PM--particulate matter
PM<INF>10</INF>--particulate matter less than 10 [mu]m in
diameter
SIP--State Implementation Plan
TSD--technical support document
Table of Contents
I. Executive Summary
[[Page 66041]]
A. What Action is the EPA Taking?
B. What is the Legal Authority and What are the Requirements?
II. Background
III. Summary of Arizona's Submittal
IV. The EPA's Evaluation of Arizona's Submittal
A. How is the EPA Evaluating the Submittal?
B. Does the Submittal Meet the Evaluation Criteria?
C. Proposed Action and Public Comment
V. Incorporation by Reference
VI. Statutory and Executive Order Reviews
I. Executive Summary
A. What Action is the EPA Taking?
The EPA is proposing to approve an August 13, 2026, SIP submittal
from Arizona that requests to add two rules to the Arizona SIP. The
rules relate to Arizona's Agricultural Best Management Practices
(AgBMP) program and are from the Arizona Administrative Code (AAC):
Title 18, Chapter 2, Section 610.03, ``Agricultural PM General Permit
for Crop Operations; Pinal County PM Nonattainment Area,'' amended
April 2, 2026 (``R18-2-610.03''), and R18-2-611.03, ``Agricultural PM
General Permit for Animal Operations: Pinal County PM Nonattainment
Area,'' amended April 2, 2026 (``R18-2-611.03''). These rules only
apply within the West Pinal County PM<INF>10</INF> nonattainment area
within Pinal County, Arizona, and were submitted to support the State's
attainment plan for the area, including the requirement to meet the
Best Available Control Measures (BACM) requirement. Previously, the EPA
proposed, but did not finalize, a limited approval and limited
disapproval of earlier versions of these two rules.\1\ The rules were
recently revised by Arizona's AgBMP Committee and we are now proposing
to fully approve them under the CAA.
---------------------------------------------------------------------------
\1\ 90 FR 5790 (Jan. 17, 2025).
---------------------------------------------------------------------------
R18-2-610.03 regulates PM<INF>10</INF> emissions from commercial
crop operations in the West Pinal County PM<INF>10</INF> nonattainment
area. R18-2-611.03 regulates PM<INF>10</INF> emissions from commercial
dairy operations, beef cattle feedlots, commercial poultry facilities,
and commercial swine facilities in the West Pinal County
PM<INF>10</INF> nonattainment area. Both rules require operators to
implement best management practices (BMPs) selected from regulatory
menus to reduce fugitive PM<INF>10</INF> emissions from their
operations. If finalized as proposed, R18-2-610.03 and R18-2-611.03
would be incorporated into the federally enforceable portion of the
Arizona SIP.
B. What is the legal authority and what are the requirements?
We are taking this proposed action under section 110 of the CAA.
Pursuant to CAA section 110(a), States are required to submit SIPs to
the EPA that provide for the implementation, maintenance, and
enforcement of the national ambient air quality standards (NAAQS). CAA
section 110(k) requires SIPs to meet certain procedural requirements
and requires the EPA to approve or disapprove SIP submissions. CAA
section 110(l) requires States to provide public notice and an
opportunity for public hearing of SIP revisions prior to their
submittal and prohibits the EPA from approving any SIP revisions that
would interfere with attainment or maintenance of a NAAQS, reasonable
further progress, or other applicable requirements of the CAA. If a SIP
submittal meets all the applicable CAA requirements, then the EPA must
approve the submittal under CAA section 110(k)(3).
For this submittal to be approved, we must consider CAA
requirements related to the emission limitations in the submitted
rules. CAA sections 110(a)(2)(A) and 302(k) require emission
limitations in the SIP to be enforceable and continuous, respectively.
CAA section 172(c)(6) requires SIPs for nonattainment areas ``include
enforceable emission limitations, and such other control measures means
or techniques . . . as well as schedules and timetables for compliance,
as may be necessary or appropriate to provide for attainment of such
standard in such area by the applicable attainment date . . . .'' Also,
40 CFR part 51, subpart K requires SIPs to contain legally enforceable
procedures for monitoring the status of compliance with the
requirements in the control strategy. While these rules were submitted
to meet BACM requirements under CAA section 189(b)(1)(B), we are not
evaluating them for BACM in this action. The EPA will evaluate BACM in
an upcoming action on the attainment plan for the West Pinal County
PM<INF>10</INF> nonattainment area.
We are proposing that this submittal meets all applicable CAA
requirements and are proposing to fully approve it under CAA section
110(k)(3).
II. Background
R18-2-610.03 and R18-2-611.03 regulate emissions of PM, including
PM<INF>10</INF>, which contribute to effects that are harmful to human
health and the environment, including premature mortality, aggravation
of respiratory and cardiovascular disease, decreased lung function,
visibility impairment, and damage to vegetation and ecosystems. Section
110(a) of the CAA requires States to submit regulations that control PM
emissions, as necessary to meet the requirements of the Act.
Previously, on January 17, 2025, we proposed a limited approval and
limited disapproval of earlier versions of R18-2-610.03 and R18-2-
611.03 (``January 2025 AgBMP proposal''), finding that the rules
strengthened the SIP but identifying enforceability and rule clarity
concerns.\2\ Following that proposal, the Arizona AgBMP Committee
revised both rules and ADEQ resubmitted them to the EPA. The updated
rules are the subject of this proposal.
---------------------------------------------------------------------------
\2\ 90 FR 5790 (Jan. 17, 2025).
---------------------------------------------------------------------------
The January 2025 AgBMP proposal also included proposing to fully
approve two related AgBMP definitions rules and the AgBMP statute: AAC
R18-2-610, ``Definitions for R18-2-610.01, R18-2-610.02, and R18-2-
610.03,'' amended November 26, 2021; AAC R18-2-611, ``Definitions for
R18-2-611.01, R18-2-611.02, and R18-2-611.03,'' amended November 26,
2021; and A.R.S. section 49-457. These provisions are not addressed in
this proposed rulemaking, and we are not requesting comment on them.
We intend to concurrently finalize action on the January 2025 AgBMP
proposal with our final action on this rulemaking.
III. Summary of Arizona's Submittal
On August 13, 2026, ADEQ submitted R18-2-610.03 and R18-2-611.03 to
the EPA for approval into the Arizona SIP. Table 1 of this document
lists the rules addressed by this proposal with the dates that they
were adopted by the Arizona Agricultural Best Management Practices
(AgBMP) Committee and submitted to the EPA by the ADEQ.
[[Page 66042]]
Table 1--Submitted Rules
----------------------------------------------------------------------------------------------------------------
Local agency Rule No. Rule title Amended Submitted
----------------------------------------------------------------------------------------------------------------
ADEQ............... AAC R18-2-610.03......... Agricultural PM April 2, 2026........ August 13, 2026.
General Permit
for Crop
Operations;
Pinal County PM
Nonattainment
Area.
ADEQ............... AAC R18-2-611.03......... Agricultural PM April 2, 2026........ August 13, 2026.
General Permit
for Animal
Operations;
Pinal County PM
Nonattainment
Area.
----------------------------------------------------------------------------------------------------------------
Under CAA section 110(k)(1), the EPA must determine whether a SIP
submittal meets the minimum completeness criteria established in 40 CFR
part 51, appendix V for an official SIP submittal on which the EPA is
obligated to take action. We find that the ADEQ's August 13, 2026 SIP
submittal for AAC R18-2-610.03 and AAC R18-2-611.03 meets the
completeness criteria in 40 CFR part 51 Appendix V. These rules apply
within the West Pinal County PM<INF>10</INF> nonattainment area in
Pinal County, Arizona, that is classified as ``Serious'' nonattainment
for the PM<INF>10</INF> NAAQS. R18-2-610.03 regulates PM<INF>10</INF>
emissions from commercial crop operations in the West Pinal County
PM<INF>10</INF> nonattainment area. R18-2-611.03 regulates
PM<INF>10</INF> emissions from commercial dairy operations, beef cattle
feedlots, commercial poultry facilities, and commercial swine
facilities in the West Pinal County PM<INF>10</INF> nonattainment area.
Both rules require operators to implement BMPs selected from regulatory
menus to reduce fugitive PM<INF>10</INF> emissions from their
operations.
We approved an earlier version of R18-2-610.03 into the Arizona SIP
on May 1, 2017.\3\ The State has specified that the present submission
of R18-2-610.03 is intended to replace this previously-approved version
of R18-2-610.03 in the SIP. This submission was also intended to
supersede the version of the rule that was submitted on March 3, 2023.
R18-2-611.03 was initially adopted by the Arizona AgBMP Committee on
November 26, 2021 and submitted to the EPA on March 3, 2023. The State
has withdrawn that version of the rule and has requested us to include
in the SIP the April 2, 2026 version of the rule instead.
---------------------------------------------------------------------------
\3\ 82 FR 20267 (May 1, 2017).
---------------------------------------------------------------------------
IV. The EPA's Evaluation of Arizona's Submittal
A. How is the EPA evaluating the submittal?
Emission limitations in the SIP must be enforceable and continuous,
and SIP revisions must not interfere with applicable requirements
concerning attainment and reasonable further progress or other CAA
requirements.\4\ Additionally, 40 CFR part 51, subpart K requires SIPs
to contain enforceable procedures for monitoring the status of
compliance with the requirements in the control strategy. Our
evaluation considered relevant guidance and policy documents.\5\
---------------------------------------------------------------------------
\4\ See, respectively, CAA sections 110(a)(2) and 172(c)(6),
302(k), and 110(l).
\5\ See, ``State Implementation Plans; General Preamble for the
Implementation of Title I of the Clean Air Act Amendments of 1990,''
57 FR 13498 (Apr. 16, 1992); 57 FR 18070 (Apr. 28, 1992); ``Guidance
Document for Correcting Common VOC & Other Rule Deficiencies,'' EPA
Region 9, August 21, 2001 (the Little Bluebook); ``State
Implementation Plans for Serious PM-10 Nonattainment Areas, and
Attainment Date Waivers for PM-10 Nonattainment Areas Generally;
Addendum to the General Preamble for the Implementation of Title I
of the Clean Air Act Amendments of 1990,'' 59 FR 41998 (Aug. 16,
1994); ``PM-10 Guideline Document,'' EPA 452/R-93-008, April 1993;
and ``Fugitive Dust Background Document and Technical Information
Document for Best Available Control Measures,'' EPA 450/2-92-004,
September 1992.
---------------------------------------------------------------------------
The West Pinal County nonattainment area is classified as Serious
for the PM<INF>10</INF> NAAQS.\6\ Generally, SIPs for Serious
PM<INF>10</INF> nonattainment areas must implement BACM, including Best
Available Control Technology.\7\ This evaluation is generally performed
in the context of a broader attainment plan. Accordingly, we will not
evaluate these rules for BACM as part of this proposed action and will
instead do so in a separate, upcoming planning action for the West
Pinal PM<INF>10</INF> nonattainment area.
---------------------------------------------------------------------------
\6\ 40 CFR 81.303.
\7\ See CAA section 189(b)(1)(B).
---------------------------------------------------------------------------
B. Does the submittal meet the evaluation criteria?
We evaluated these rules to ensure they meet CAA requirements and
are consistent with relevant guidance regarding enforceability and SIP
revisions.
With respect to emission limitations being enforceable and
continuous, the revised rules specify clear requirements, providing
regulatory certainty to the regulated community. The rules'
implementation details are also sufficient for State enforcement, and
emission limits apply on a continuous basis. The resubmitted rules
require annual, non-anonymous reporting of BMP selections and
certifications directly to ADEQ (or through the Arizona Department of
Agriculture as an optional intermediary for crop operations), with form
contents that include identifying BMP selections for the upcoming year,
area and crop/operation identification, and certification of prior-year
implementation. These requirements enable ADEQ to identify which BMPs
each operator has committed to implement, verify implementation during
inspections, and document noncompliance on an individual operator
basis. These revisions strengthen the clarity and enforceability of the
rules, address the concerns identified in our January 2025 AgBMP
proposal, and meet the relevant CAA enforceability requirements.
With respect to SIP revisions under CAA section 110(l), approval of
the revised rules would not interfere with any applicable CAA
requirements, including requirements for reasonable further progress
and attainment. R18-2-610.03 is more stringent than the current SIP-
approved version of R18-2-610.03, requiring two BMPs per category,
adding new BMP categories, and adding a new 20 percent opacity limit
for high-traffic unpaved areas. R18-2-611.03 is a new rule with respect
to the Arizona SIP and is thus a substantial strengthening. The rules
do not interfere with any other relevant CAA requirements. The EPA's
technical support document (TSD) has more information about these
rules.
Based on our review, the rules meet the relevant CAA requirements.
C. Proposed Action and Public Comment
As authorized in section 110(k)(3) of the CAA, the EPA proposes to
approve the submitted rules because they fulfill all relevant
requirements. We will accept comments from the public on this proposal
until November 18, 2026. If we finalize approval, our final action will
incorporate these rules into the federally enforceable SIP.
Specifically, the EPA is proposing to approve AAC R18-2-610.03,
``Agricultural PM General Permit for Crop Operations; Pinal County PM
Nonattainment Area,'' and AAC R18-2-
[[Page 66043]]
611.03, ``Agricultural PM General Permit for Animal Operations; Pinal
County PM Nonattainment Area,'' as revised on April 2, 2026, and
submitted by ADEQ on May 15, 2026. If we finalize this proposed
approval, the April 2, 2026 version of AAC R18-2-610.03 will replace
the previously SIP-approved version of this rule,\8\ and AAC R18-2-
611.03 will be newly added to the Arizona SIP.
---------------------------------------------------------------------------
\8\ 82 FR 20267 (May 1, 2017).
---------------------------------------------------------------------------
This proposed approval supersedes, with respect to AAC R18-2-610.03
and AAC R18-2-611.03, the proposed limited approval and limited
disapproval of earlier versions of these rules from the 2025 AgBMP
proposal. This proposal does not change our analysis and proposal with
respect to A.R.S. section 49-457, AAC R18-2-610, or AAC R18-2-611 from
the January 2025 AgBMP proposal.
V. Incorporation by Reference
In this document, the EPA is proposing to include in a final EPA
rule, regulatory text that includes incorporation by reference. In
accordance with requirements of 1 CFR 51.5, the EPA is proposing to
incorporate by reference AAC R18-2-610.03, ``Agricultural PM General
Permit for Crop Operations; Pinal County PM Nonattainment Area,''
amended April 2, 2026, which regulates PM<INF>10</INF> emissions from
commercial crop operations in the West Pinal County PM<INF>10</INF>
nonattainment area; and AAC R18-2-611.03, ``Agricultural PM General
Permit for Animal Operations; Pinal County PM Nonattainment Area,'' as
revised April 2, 2026, which regulates PM<INF>10</INF> emissions from
commercial dairy operations, beef cattle feedlots, poultry facilities,
and swine facilities in the West Pinal County PM<INF>10</INF>
nonattainment area. The EPA has made, and will continue to make, these
materials available through <a href="https://www.regulations.gov">https://www.regulations.gov</a> and at the EPA
Region IX Office (please contact the person identified in the FOR
FURTHER INFORMATION CONTACT section of this preamble for more
information).
VI. Statutory and Executive Order Reviews
Under the Clean Air Act, the Administrator is required to approve a
SIP submission that complies with the provisions of the Clean Air 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 proposed action merely proposes approval of State law
as meeting Federal requirements and does not impose additional
requirements beyond those imposed by State law. For that reason, this
action:
<bullet> 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);
<bullet> Is not an Executive Order 14192 (90 FR 9065, February 6,
2025) regulatory action because this proposed action is not significant
under Executive Order 12866;
<bullet> Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
<bullet> 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.);
<bullet> 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);
<bullet> Does not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
<bullet> Is not subject to Executive Order 13045 (62 FR 19885,
April 23, 1997) because it approves a State program;
<bullet> Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001); and
<bullet> 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 Clean Air Act.
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 rule 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).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Particulate matter, Reporting
and recordkeeping requirements.
Authority: 42 U.S.C. 7401 et seq.
Dated: October 14, 2026.
Michael Martucci,
Acting Regional Administrator, Region IX.
[FR Doc. 2026-21289 Filed 10-16-26; 8:45 am]
BILLING CODE 6569-60-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on October 19, 2026.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.