Approval and Promulgation of State Plans for Designated Facilities and Pollutants; Arizona; Control of Emissions From Existing Municipal Solid Waste Landfills

Issuing agencies

Abstract

The Environmental Protection Agency (EPA) is proposing to approve a State plan submitted by the Maricopa County Air Quality Department (MCAQD). This plan pertains to the regulation of landfill gas and its components from existing municipal solid waste (MSW) landfills. Maricopa's county plan was submitted in response to the EPA's promulgation of Emissions Guidelines and Compliance Times for MSW landfills. This action is being taken under the Clean Air Act (CAA).

Full Text

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<title>Federal Register, Volume 91 Issue 213 (Thursday, November 5, 2026)</title>
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[Federal Register Volume 91, Number 213 (Thursday, November 5, 2026)]
[Proposed Rules]
[Pages 69761-69763]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-22585]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 62

[EPA-R09-OAR-2026-5710; FRL-13516-01-R9]


Approval and Promulgation of State Plans for Designated 
Facilities and Pollutants; Arizona; Control of Emissions From Existing 
Municipal Solid Waste Landfills

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve a State plan submitted by the Maricopa County Air Quality 
Department (MCAQD). This plan pertains to the regulation of landfill 
gas and its components from existing municipal solid waste (MSW) 
landfills. Maricopa's county plan was submitted in response to the 
EPA's promulgation of Emissions Guidelines and Compliance Times for MSW 
landfills. This action is being taken under the Clean Air Act (CAA).

DATES: Written comments must be received on or before December 7, 2026.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2026-5710 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>. For either manner of submission, 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>.

FOR FURTHER INFORMATION CONTACT: Jeffrey Buss, U.S. EPA Region IX, 
telephone number: (415) 947-4152, email address: <a href="/cdn-cgi/l/email-protection#c7a5b2b4b4e9ada2a1a1b5a2be87a2b7a6e9a0a8b1"><span class="__cf_email__" data-cfemail="7e1c0b0d0d50141b18180c1b073e1b0e1f50191108">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION: Throughout this proposed rule, the use of 
``we,'' ``us,'' or ``our'' is intended to 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:

ADEQ Arizona Department of Environmental Quality
CAA Clean Air Act
CBI confidential business information
EG emission guideline
MCAQD Maricopa County Air Quality Department
MSW municipal solid waste
NSPS New Source Performance Standards
TSD Technical Support Document

Table of Contents

I. Executive Summary
    A. What action is the EPA taking?
    B. What is the legal authority and what are the requirements?
II. Background
III. Summary of the Plan and EPA Analysis
IV. Proposed Action
V. Incorporation by Reference
VI. Statutory and Executive Order Reviews

I. Executive Summary

A. What action is the EPA taking?

    The Environmental Protection Agency (EPA) is proposing to approve a 
State plan submitted by the Maricopa County Air Quality Department 
(MCAQD) pursuant to Clean Air Act (CAA) section 111(d). This plan 
pertains to the regulation of landfill gas and its components from 
existing municipal solid waste (MSW) landfills. Maricopa's county plan 
was submitted in response to the EPA's promulgation of Emissions 
Guidelines and Compliance Times for MSW landfills.\1\
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    \1\ See 81 FR 5927 (Aug. 29, 2016).
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B. What is the legal authority and what are the requirements?

    The EPA is proposing to approve the MCAQD's October 4, 2022 section 
111(d) plan submittal for existing MSW landfills submitted pursuant to 
40 CFR part 60, subparts B and Cf. Therefore, the EPA is proposing to 
amend 40 CFR part 62, subpart D, to reflect this action. This approval 
is based on the rationale discussed below and in further detail in the 
Technical Support Document (TSD) associated with this action. The scope 
of the proposed approval of the section 111(d) plan is limited to the 
provisions of 40 CFR parts 60 and 62 for existing MSW landfills, as 
referenced in the Emission Guidelines (EGs), subpart Cf.

II. Background

    CAA section 111(b)(1)(A) requires the EPA Administrator to 
promulgate a list of categories of stationary sources that the 
Administrator, ``in his judgment,'' finds ``causes, or contributes 
significantly to, air pollution which may reasonably be anticipated to 
endanger public health or welfare.'' The EPA has the authority under 
this section to define the scope of the source categories; to 
determine, consistent with the statutory requirements, the pollutants 
for which standards should be developed; and to distinguish among 
classes, types, and sizes within categories in establishing the 
standards.\2\ Once the EPA lists a source category that contributes 
significantly to dangerous air pollution, the EPA must, under CAA 
section 111(b)(1)(B), establish ``standards of performance'' for ``new 
sources'' in the source category. These standards are referred to as 
new source performance standards, or NSPS. The NSPS are national 
requirements that apply directly to the sources subject to them.
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    \2\ 42 U.S.C. 7411(b)(2) provides the EPA the authority to 
establish subcategories.
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    The basis for standards of performance is the ``degree of emission 
limitation'' that is ``achievable'' by sources in the source category 
by application of the ``best system of emission reduction'' that the 
EPA determines is ``adequately demonstrated'' (BSER). As explained 
further below in this section, the D.C. Circuit has explained that 
systems are not ``adequately demonstrated'' if they are ``purely 
theoretical or experimental.'' \3\ The D.C. Circuit has stated that in 
determining the ``best'' adequately demonstrated system for the 
pollutants at issue, the EPA must also take into account ``the amount 
of air pollution'' reduced.\4\ The D.C. Circuit has also stated that 
the EPA may weigh the various factors identified in the statute and 
caselaw to determine the ``best'' system and has emphasized that

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the EPA has significant discretion in weighing the factors.\5\
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    \3\ Essex Chem. Corp. v. Ruckelshaus, 486 F.2d 427, 433-34 (D.C. 
Cir. 1973).
    \4\ See Sierra Club v. Costle, 657 F.2d 298, 326 (D.C. Cir. 
1981). The D.C. Circuit has stated that EPA must also take into 
account ``technological innovation.'' See id. at 347.
    \5\ See Lignite Energy Council v. EPA, 198 F.3d 930, 933 (D.C. 
Cir. 1999)(``Because section 111 does not set forth the weight that 
should be assigned to each of these factors, we have granted the 
agency a great degree of discretion in balancing them.'').
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    After determining the BSER, the EPA sets an achievable emission 
limit based on application of the BSER.\6\ For a CAA section 111(b) 
rule, the EPA determines the standard of performance that reflects the 
achievable emission limit. For a CAA section 111(d) rule, the States 
have the obligation of establishing standards of performance for the 
affected sources that reflect the degree of emission limitation that 
the EPA has determined and provided to States as part of an emission 
guideline. In applying these standards to existing sources, States are 
permitted to take a source's remaining useful life and other factors 
into account.
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    \6\ See, e.g., Oil and Natural Gas Sector: New Source 
Performance Standards and National Emission Standards for Hazardous 
Air pollutants Reviews (77 FR 49494; August 16, 2012) (describing 
the three-step analysis in setting a standard of performance).
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    On March 12, 1996, the EPA promulgated an NSPS applicable to 
certain new municipal solid waste (MSW) landfills and EGs for certain 
existing landfills in 40 CFR part 60, subparts WWW and Cc, 
respectively. These regulations were intended to control landfill gases 
such as non-methane organic compounds and odorous compounds.\7\ On June 
17, 1997, and June 29, 1999, the Arizona Department of Environmental 
Quality (ADEQ) submitted a plan adopting 40 CFR 60, subpart Cc. The 
ADEQ's plan covered the twelve counties under its jurisdiction as well 
as applicable rules for the remaining three counties with their own 
jurisdiction over MSW landfills: Pima, Pinal, and Maricopa counties. 
The EPA approved the plan on September 20, 1999,\8\ and it took effect 
on November 19, 1999.
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    \7\ 61 FR 9905.
    \8\ 64 FR 50768.
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    On August 29, 2016, the EPA finalized revisions to the MSW landfill 
NSPS and EGs in 40 CFR part 60, subparts XXX and Cf, respectively.\9\ 
The 2016 EG revision updated the control requirements and monitoring, 
reporting, and recordkeeping provisions for existing MSW landfills. The 
current MSW landfill EGs regulates landfill gas and its components from 
MSW landfills for which construction, reconstruction, or modification 
commenced on or before July 17, 2014. The deadline for States to submit 
a plan to the EPA to implement the EGs was May 30, 2017. On May 21, 
2021, the EPA finalized the MSW landfill Federal Plan in 40 CFR part 
62, subpart OOO, that applies to States that do not have an EPA-
approved State plan to implement the EG. In the absence of an approved 
State plan, the EPA is responsible for developing, implementing, and 
enforcing the Federal Plan.
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    \9\ 81 FR 59332 and 81 FR 59276, respectively.
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    On October 4, 2022, the Maricopa County Air Quality Department 
(MCAQD) submitted to the EPA a section 111(d) plan for existing MSW 
landfills. The submitted section 111(d) plan was in response to the 
August 29, 2016, promulgation of federal NSPS and EG requirements for 
MSW landfills, 40 CFR part 60, subparts XXX and Cf, respectively. In 
addition, on July 5, 2023, the MCAQD and the EPA entered into a 
memorandum of agreement delegating authority to implement and enforce 
the Federal Plan to the MCAQD.\10\ This delegation remains in effect 
until the EPA approves the MCAQD's MSW landfill plan. State plan 
submittals and revisions under CAA section 111(d) must be consistent 
with the applicable EGs and the requirements of 40 CFR part 60, subpart 
B. These requirements include general provisions applicable to the 
adoption and submittal of State plans under CAA section 111(d). 
Additionally, State plan submittals and revisions are also subject to 
40 CFR part 60, subpart A. This subpart establishes the procedural 
framework by which the EPA will approve or disapprove State plan 
submittals. Once approved by the EPA, the State plan becomes federally 
enforceable.
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    \10\ Memorandum of Agreement, Delegation of Authority of the 
Federal Plan for Existing Municipal Solid Waste Landfills Between 
the Maricopa County Air Quality Department and the United States 
Environmental Protection Agency, signed by Martha Guzman Aceves, 
Regional Administrator, on July 5, 2023, and signed by Clint L. 
Hickman Chairman, Maricopa County Board of Supervisors, on June 14, 
2023, Juanita Garza, Clerk of the Board, Maricopa County Board of 
Supervisors, on June 14, 2023, and Karen J. Hartman-Tellez, Deputy 
City Attorney, on May 4, 2023.
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III. Summary of the Plan and EPA Analysis

    The EPA has reviewed the October 4, 2022 section 111(d) plan 
submittal in the context of the requirements of 40 CFR part 60, 
subparts B and Cf, and part 62, subpart A. In this action, the EPA is 
proposing to determine that the submitted section 111(d) plan meets the 
above-cited requirements. The primary mechanism selected by the MCAQD 
to implement the EGs for existing MSW landfills under State 
jurisdiction is through incorporation by reference of 40 CFR part 60, 
subpart Cf, into the Maricopa County Air Pollution Control Regulations 
(under Regulation III--Control of Air Contaminants, Rule 321, Existing 
Municipal Solid Waste (MSW) Landfills), on September 28, 2022. While 
the MCAQD submitted the entire Rule 321, it asked that the EPA only 
take action on the portion of the rule applicable to the MSW EGs.\11\ A 
detailed explanation of the rationale behind this proposed approval is 
available in the TSD.
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    \11\ Email dated June 10, 2026, from Gregory Verkamp, MCAQD to 
Jeffrey Buss, EPA Region IX, Subject: ``RE: Maricopa section 111 d 
plan--MSW landfills.''
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IV. Proposed Action

    The EPA is proposing to approve the MCAQD's October 4, 2022 section 
111(d) plan submittal for existing MSW landfills submitted pursuant to 
40 CFR part 60, subparts B and Cf. Therefore, the EPA is proposing to 
amend 40 CFR part 62, subpart D, to reflect this action. This approval 
is based on the rationale discussed above and in further detail in the 
TSD associated with this action. The scope of the proposed approval of 
the section 111(d) plan is limited to the provisions of 40 CFR parts 60 
and 62 for existing MSW landfills, as referenced in the EGs, subpart 
Cf.

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 of the 
State plan. In accordance with requirements of 1 CFR 51.5, EPA is 
proposing to incorporate by reference MCAQD rules regarding MSW 
landfills discussed in section III of this preamble. The EPA has made, 
and will continue to make, these materials generally available through 
<a href="https://www.regulations.gov">https://www.regulations.gov</a>, Docket ID No. EPA-R09-OAR-2026-5710, 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 CAA, the Administrator is required to approve a CAA 
section 111(d) submission that complies with the provisions of the Act 
and applicable Federal regulations. 42 U.S.C. 7411(d); 40 CFR part 60, 
subparts B and Cf; and 40 CFR part 62, subpart A. Thus, in reviewing 
CAA section 111(d) State plan submissions, EPA's role is to approve 
State choices, provided that they meet the criteria of the Act and 
implementing regulations. Accordingly,

[[Page 69763]]

this action merely proposes to approve State law as meeting Federal 
requirements and does not impose additional requirements beyond those 
imposed by State law. For that reason:

A. Executive Order 12866: Regulatory Planning and Review

    This action is not a significant regulatory action as defined in 
Executive Order 12866 (58 FR 51735, October 4, 1993) and was therefore 
not subject to a requirement for Executive Order 12866 review.

B. Executive Order 14192: Unleashing Prosperity Through Deregulation

    This action is not an Executive Order 14192 regulatory action 
because this action is not significant under Executive Order 12866.

C. Paperwork Reduction Act (PRA)

    This action does not impose an information collection burden under 
the PRA (44 U.S.C. 3501 et seq.) because it does not contain any 
information collection activities.

D. Regulatory Flexibility Act (RFA)

    This action is certified to 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 approve a State plan pursuant to CAA section 
111(d) and will therefore have no net regulatory burden for all 
directly regulated small entities.

E. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in 
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect 
small governments. This action imposes no enforceable duty on any 
State, local, or tribal governments or the private sector.

F. Executive Order 13132: Federalism

    This action does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999). 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.

G. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This action will not apply to areas of Indian country within 
Arizona and therefore does not have tribal implications as specified in 
E.O. 13175 (65 FR 67249, November 9, 2000). This action will neither 
impose substantial direct compliance costs on federally recognized 
tribal governments, nor preempt tribal law. This action will not impose 
substantial direct compliance costs on federally recognized tribal 
governments because no actions will be required of tribal governments. 
This action will also not preempt tribal law as no Arizona tribe 
implements a regulatory program under the CAA and thus does not have 
applicable or related tribal laws.

H. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    EPA interprets Executive Order 13045 (62 FR 19885, April 23, 1997) 
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 definitions of ``covered 
regulatory action'' in section 2-202 of the Executive Order. Therefore, 
this action is not subject to Executive Order 13045 because it approves 
a State program.

I. Executive Order 13211: Actions That Significantly Affect Energy 
Supply, Distribution and Use

    This action is not subject to Executive Order 13211 (66 FR 28355, 
May 22, 2001), because it is not a significant regulatory action under 
Executive Order 12866.

J. National Technology Transfer and Advancement Act

    This rulemaking does not involve technical standards. This action 
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.

List of Subjects in 40 CFR Part 62

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Landfills, Reporting and 
recordkeeping requirements, Waste Treatment and Disposal.

    Authority:  42 U.S.C. 7401 et seq.

    Dated: October 22, 2026.
Michael Martucci,
Acting Regional Administrator, Region IX.
[FR Doc. 2026-22585 Filed 11-4-26; 8:45 am]
BILLING CODE 6569-60-P


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