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Proposed Rule2026-05491

Standards for Air Curtain Incinerators That Only Burn Wood Wastes, Yard Wastes and Clean Lumber; Provision for Commercial and Industrial Solid Waste Incineration Units: Temporary Use Incinerators and Air Curtain Incinerators Used in Disaster Recovery

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Published

March 20, 2026

Issuing agencies

Environmental Protection Agency

Abstract

The U.S. Environmental Protection Agency (EPA) is proposing two separate and distinct actions under Clean Air Act (CAA) section 129. In the first action, the EPA proposes to consolidate the existing provisions governing air curtain incinerators (ACI) that only burn wood wastes, yard wastes, and clean lumber into one new rule subpart. Specifically, we are proposing to consolidate the opacity limitations and associated monitoring, recordkeeping, and reporting requirements that currently exist across various subparts for CAA section 129 source categories: large municipal waste combustors (LMWC), small municipal waste combustors (SMWC), commercial and industrial solid waste incinerators (CISWI), and other solid waste incinerators (OSWI). We are also proposing to remove the permitting requirement for this type of ACI that are not located at major sources or subject to federal permitting requirements for other reasons. The proposed removal would not cover ACI that are currently subject to OSWI or LMWC rules which have already been amended to remove such permitting requirements. In the second action, the EPA proposes to include in the CISWI rule subparts provisions for the temporary use of CISWI units to combust debris from a qualifying disaster or emergency on a temporary basis without complying with (CAA) section 129 requirements that would otherwise apply to CISWI units for the combustion of commercial and industrial waste during normal operations. These additional provisions would bring the CISWI rule subparts into alignment with existing OSWI provisions that allow such temporary use of OSWI units to combust debris from a disaster or emergency.

Full Text

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<title>Federal Register, Volume 91 Issue 54 (Friday, March 20, 2026)</title>
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[Federal Register Volume 91, Number 54 (Friday, March 20, 2026)]
[Proposed Rules]
[Pages 13543-13559]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-05491]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 60 and 62

[EPA-HQ-OAR-2025-0068; FRL-12906-03-OAR]
RIN 2060-AW92

Standards for Air Curtain Incinerators That Only Burn Wood
Wastes, Yard Wastes and Clean Lumber; Provision for Commercial and
Industrial Solid Waste Incineration Units: Temporary Use Incinerators
and Air Curtain Incinerators Used in Disaster Recovery

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule; request for comment.

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SUMMARY: The U.S. Environmental Protection Agency (EPA) is proposing
two separate and distinct actions under Clean Air Act (CAA) section
129. In the first action, the EPA proposes to consolidate the existing
provisions governing air curtain incinerators (ACI) that only burn wood
wastes, yard wastes, and clean lumber into one new rule subpart.
Specifically, we are proposing to consolidate the opacity limitations
and associated monitoring, recordkeeping, and reporting requirements
that currently exist across various subparts for CAA section 129 source
categories: large municipal waste combustors (LMWC), small municipal
waste combustors (SMWC), commercial and industrial solid waste
incinerators (CISWI), and other solid waste incinerators (OSWI). We are
also proposing to remove the permitting requirement for this type of
ACI that are not located at major sources or subject to federal
permitting requirements for other reasons. The proposed removal would
not cover ACI that are currently subject to OSWI or LMWC rules which
have already been amended to remove such permitting requirements. In
the second action, the EPA proposes to include in the CISWI rule
subparts provisions for the temporary use of CISWI units to combust
debris from a qualifying disaster or emergency on a temporary basis
without complying with (CAA) section 129 requirements that would
otherwise apply to CISWI units for the combustion of commercial and
industrial waste during normal operations. These additional provisions
would bring the CISWI rule subparts into alignment with existing OSWI
provisions that allow such temporary use of OSWI units to combust
debris from a disaster or emergency.

DATES: Comments must be received on or before May 4, 2026. Under the
Paperwork Reduction Act, comments on the information collection
provisions are best assured of consideration if the Office of
Management and Budget (OMB) receives a copy of your comments on or
before April 20, 2026.
Public hearing: If anyone contacts us requesting a public hearing
on or before Wednesday, March 25, 2026, we will hold a virtual public
hearing. See SUPPLEMENTARY INFORMATION for information on requesting
and registering for a public hearing.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OAR-2025-0068, by any of the following methods:
<bullet> Federal eRulemaking Portal: <a href="http://www.regulations.gov">www.regulations.gov</a> (our
preferred method). Follow the online instructions for submitting
comments.
<bullet> Email: <a href="/cdn-cgi/l/email-protection#9dfcb0fcf3f9b0efb0f9f2fef6f8e9ddf8edfcb3faf2eb">[email&#160;protected]</a>. Include Docket ID No. EPA-
HQ-OAR-2025-0068 in the subject line of the message.
<bullet> Mail: U.S. Environmental Protection Agency, EPA Docket
Center, Docket ID No. EPA-HQ-OAR-2025-0068, Mail Code 28221T, 1200
Pennsylvania Avenue NW, Washington, DC 20460.
<bullet> Hand/Courier Delivery: EPA Docket Center, WJC West
Building, Room 3334, 1301 Constitution Avenue NW,

[[Page 13544]]

Washington, DC 20004. The Docket Center's hours of operation are 8:30
a.m.-4:30 p.m., Monday-Friday (except Federal holidays).
Instructions: All submissions received must include the Docket ID
No. for this rulemaking. Comments received may be posted without change
to <a href="http://www.regulations.gov">www.regulations.gov</a>, including any personal information provided.
For detailed instructions on sending comments and additional
information on the rulemaking process, see the SUPPLEMENTARY
INFORMATION section of this document.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed
rule, contact Tianzhen Nie, Natural Resources Division (E243-05),
Office of Clean Air Programs, U.S. Environmental Protection Agency, 109
T.W. Alexander Drive, P.O. Box 12055, Research Triangle Park, North
Carolina 27711; telephone number: (919) 541-1815 and email address:
<a href="/cdn-cgi/l/email-protection#e7898e82c9938e86899d8f8289a7829786c9808891">[email&#160;protected]</a>.

SUPPLEMENTARY INFORMATION:
Participation in virtual public hearing. To request a virtual
public hearing, contact the public hearing team at (888) 627-7764 or by
email at <a href="/cdn-cgi/l/email-protection#d29c8096a2a7b0bebbb1bab7b3a0bbbcb592b7a2b3fcb5bda4">[email&#160;protected]</a>. If requested, the hearing will be
held via virtual platform on April 6, 2026. The EPA may close a session
15 minutes after the last pre-registered speaker has testified if there
are no additional speakers. The EPA will announce further details at
<a href="https://www.epa.gov/stationary-sources-air-pollution/air-curtain-incinerators-only-burn-wood-wastes-yard-wastes-and">https://www.epa.gov/stationary-sources-air-pollution/air-curtain-incinerators-only-burn-wood-wastes-yard-wastes-and</a>.
The EPA will begin pre-registering speakers for the hearing no
later than one business day after a request has been received. To
register to speak at the virtual hearing, please use the online
registration form available at <a href="https://www.epa.gov/stationary-sources-air-pollution/air-curtain-incinerators-only-burn-wood-wastes-yard-wastes-and">https://www.epa.gov/stationary-sources-air-pollution/air-curtain-incinerators-only-burn-wood-wastes-yard-wastes-and</a> or contact the public hearing team at (888) 627-7764 or by
email at <a href="/cdn-cgi/l/email-protection#9ad4c8deeaeff8f6f3f9f2fffbe8f3f4fddaffeafbb4fdf5ec">[email&#160;protected]</a>. The last day to pre-register to
speak at the hearing will be Wednesday, April 1, 2026. Prior to the
hearing, the EPA will post a general agenda that will list pre-
registered speakers at: <a href="https://www.epa.gov/stationary-sources-air-pollution/air-curtain-incinerators-only-burn-wood-wastes-yard-wastes-and">https://www.epa.gov/stationary-sources-air-pollution/air-curtain-incinerators-only-burn-wood-wastes-yard-wastes-and</a>.
The EPA will make every effort to follow the schedule as closely as
possible on the day of the hearing; however, please plan for the
hearing to run either ahead of schedule or behind schedule.
Each commenter will have four minutes to provide oral testimony.
The EPA encourages commenters to submit the text of your oral testimony
as written comments to the rulemaking docket.
The EPA may ask clarifying questions during the oral presentations
but will not respond to the presentations at that time. Written
statements and supporting information submitted during the comment
period will be considered with the same weight as oral testimony and
supporting information presented at the public hearing.
Please note that any updates made to any aspect of the hearing will
be posted online at <a href="https://www.epa.gov/stationary-sources-air-pollution/air-curtain-incinerators-only-burn-wood-wastes-yard-wastes-and">https://www.epa.gov/stationary-sources-air-pollution/air-curtain-incinerators-only-burn-wood-wastes-yard-wastes-and</a>. While the EPA expects the hearing to be conducted as set forth
earlier, please monitor our website or contact the public hearing team
at 888-627-7764 or by email at <a href="/cdn-cgi/l/email-protection#8ac4d8cefaffe8e6e3e9e2efebf8e3e4edcaeffaeba4ede5fc">[email&#160;protected]</a> to determine if
there are any updates. The EPA does not intend to publish a document in
the Federal Register announcing updates. If you require the services of
a translator or special accommodation such as audio description, please
pre-register for the hearing with the public hearing team and describe
your needs by Friday, March 27, 2026. The EPA may not be able to
arrange accommodations without advanced notice.
Docket. The EPA has established a docket for this rulemaking under
Docket ID No. EPA-HQ-OAR-2025-0068. All documents in the docket are
listed at <a href="http://www.regulations.gov">www.regulations.gov</a>. Although listed, 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. With the
exception of such material, publicly available docket materials are
available electronically at <a href="http://www.regulations.gov">www.regulations.gov</a>.
Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-
2025-0068. The EPA's policy is that all comments received will be
included in the public docket without change and may be made available
online at <a href="http://www.regulations.gov">www.regulations.gov</a>, including any personal information
provided, unless the comment includes information claimed to be CBI,
Proprietary Business Information (PBI), or other information whose
disclosure is restricted by statute. Do not submit information that you
consider to be CBI, PBI, or otherwise protected through
<a href="http://www.regulations.gov">www.regulations.gov</a> or email. This type of information should be
submitted as discussed below.
The EPA may publish any comment received to its public docket.
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, PBI, or multimedia
submissions, and general guidance on making effective comments, please
visit <a href="http://www.epa.gov/dockets/commenting-epa-dockets">www.epa.gov/dockets/commenting-epa-dockets</a>.
The <a href="http://www.regulations.gov">www.regulations.gov</a> website allows you to submit your comment
anonymously, which means the EPA will not know your identity or contact
information unless you provide it in the body of your comment. If you
send an email comment directly to the EPA without going through
<a href="http://www.regulations.gov">www.regulations.gov</a>, your email address will be automatically captured
and included as part of the comment that is placed in the public docket
and made available on the internet. If you submit an electronic
comment, the EPA recommends that you include your name and other
contact information in the body of your comment and with any digital
storage media you submit. If the EPA cannot read your comment due to
technical difficulties and cannot contact you for clarification, the
EPA may not be able to consider your comment. Electronic files should
not include special characters or any form of encryption and should be
free of any defects or viruses. For additional information about the
EPA's public docket, visit the EPA Docket Center homepage at
<a href="http://www.epa.gov/dockets">www.epa.gov/dockets</a>.
The EPA is soliciting comments on numerous aspects in this
document. The EPA has indexed each comment solicitation with a unique
identifier (e.g., ``ACI-1,'' ``ACI-2,'' ``OSWI-1'' . . .) to provide a
consistent framework for effective and efficient provision of comments.
Requests for comment solicitation are organized by category, and can be
found in sections V, VI, and XI of this preamble. Accordingly, we ask
that commenters include the corresponding identifier when providing
comments relevant to that comment solicitation. We ask that commenters
include the identifier either in a heading or within the text of each
comment, to make clear which comment

[[Page 13545]]

solicitation is being addressed. We emphasize that we are not limiting
comments to these identified areas and encourage provision of any other
comments relevant to this proposed action.
Submitting CBI. Do not submit information containing CBI to the EPA
through <a href="http://www.regulations.gov">www.regulations.gov</a> or email. Clearly mark the part or all of
the information that you claim to be CBI. For CBI information on any
digital storage media that you mail to the EPA, mark the outside of the
digital storage media as CBI and then identify electronically within
the digital storage media the specific information that is claimed as
CBI. In addition to one complete version of the comments that includes
information claimed as CBI, you must submit a copy of the comments that
does not contain the information claimed as CBI directly to the public
docket through the procedures outlined in the Instructions section
above. If you include other information whose disclosure is restricted
by statute in your comment, clearly mark your submission as including
that information. If you submit any digital storage media that does not
contain CBI, mark the outside of the digital storage media clearly that
it does not contain CBI and note the docket ID. Information not marked
as CBI will be included in the public docket and the EPA's electronic
public docket without prior notice. Information marked as CBI will not
be disclosed except in accordance with procedures set forth in 40 Code
of Federal Regulations (CFR) part 2. Information whose disclosure is
otherwise restricted by statute will be processed by the EPA Docket
Center in accordance with the applicable statute.
Our preferred method to receive CBI is for it to be transmitted
electronically using email attachments, File Transfer Protocol (FTP),
or other online file sharing services (e.g., Dropbox, OneDrive, Google
Drive). Electronic submissions must be transmitted directly to the
Office of Clean Air Programs CBI Office at the email address
<a href="/cdn-cgi/l/email-protection#81eee0f0f1f2dee2e3e8c1e4f1e0afe6eef7">[email&#160;protected]</a>, and as described above, should include clear CBI
markings and note the docket ID. If assistance is needed with
submitting large electronic files that exceed the file size limit for
email attachments, and if you do not have your own file sharing
service, please email <a href="/cdn-cgi/l/email-protection#6708061617143804050e2702170649000811">[email&#160;protected]</a> to request a file transfer
link. If sending CBI information through the postal service, please
send it to the following address: OCAP Document Control Officer (C404-
02), OCAP, U.S. Environmental Protection Agency, 109 T.W. Alexander
Drive, P.O. Box 12055, Research Triangle Park, North Carolina 27711,
Attention Docket ID No. EPA-HQ-OAR-2025-0068. The mailed CBI material
should be double wrapped and clearly marked. Any CBI markings should
not show through the outer envelope. Note that written comments
containing CBI and submitted by mail may be delayed and no hand
deliveries will be accepted.
Preamble acronyms and abbreviations. Throughout this preamble the
use of ``we,'' ``us,'' or ``our'' is intended to refer to the EPA. We
use multiple acronyms and terms in this preamble. While this list may
not be exhaustive, to ease the reading of this document and for
reference purposes, the EPA defines the following terms and acronyms
here:

ACI Air Curtain Incinerator
ANSI American National Standards Institute
CAA Clean Air Act
CBI Confidential Business Information
CFR Code of Federal Regulations
CISWI Commercial and Industrial Solid Waste Incinerator
DCOT Digital Camera Opacity Technique
EG Emission Guidelines
EPA Environmental Protection Agency
FR Federal Register
ICR Information Collection Request
LMWC Large Municipal Waste Combustor
MSW Municipal Solid Waste
NSPS New Source Performance Standards
NTTAA National Technology Transfer and Advancement Act
OMB Office of Management and Budget
OSWI Other Solid Waste Incinerator
PBI Proprietary Business Information
PRA Paperwork Reduction Act
RFA Regulatory Flexibility Act
SMWC Small Municipal Waste Combustor
TPD Tons Per Day
UMRA Unfunded Mandates Reform Act
VCS Voluntary Consensus Standard

Table of Contents

I. General Information for ACI That Only Burn Wood Wastes, Yard
Waste, and Clean Lumber
A. Executive Summary
B. Does this proposed action apply to me?
C. Where can I get a copy of this document and other related
information?
II. Background for ACI That Only Burn Wood Wastes, Yard Wastes, and
Clean Lumber
A. What is the statutory history of this action?
B. What is the regulatory history for this action?
III. Proposed Actions for ACI That Only Burn Wood Wastes, Yard
Wastes, and Clean Lumber
A. Proposed Consolidation of the Existing Opacity Limits for ACI
That Only Burn Wood Wastes, Yard Wastes, and Clean Lumber
B. Proposed Removal of Existing Title V Requirements for ACI
That Only Burn Wood Wastes, Yard Wastes, and Clean Lumber
IV. Summary of Cost, Environmental, and Economic Impacts for ACI
That Only Burn Wood Wastes, Yard Wastes, and Clean Lumber
V. Request for Comments on Proposed Rule for ACIs That Only Burn
Wood Wastes, Yard Wastes, and Clean Lumber
VI. Request for Comments on Revising the Definition of ``Municipal
Waste Combustion Unit'' in OSWI NSPS and EG
VII. General Information for Temporary Use of CISWI Units in
Disaster Recovery
A. Executive Summary
B. Does this proposed action apply to me?
C. Where can I get a copy of this document and other related
information?
VIII. Background for Temporary Use of CISWI Units in Disaster
Recovery
A. What is the statutory history of this action?
B. What is the regulatory history of this action?
IX. Rationale for Temporary Use of CISWI Units in Disaster Recovery
A. Temporary Use of CISWI During Disaster Recovery
B. Temporary Use Period and Notifications
X. Summary of Cost, Environmental, and Economic Impacts for CISWI
Temporary Use Incinerators in Disaster Recovery
XI. Request for Comment for CISWI Temporary Use Incinerators in
Disaster Recovery
XII. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
B. Executive Order 14192: Unleashing Prosperity Through
Deregulation
C. Paperwork Reduction Act (PRA)
D. Regulatory Flexibility Act (RFA)
E. Unfunded Mandates Reform Act (UMRA)
F. Executive Order 13132: Federalism
G. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
H. Executive Order 13045: Protection of Children From
Environmental Health Risks and Safety Risks
I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
J. National Technology Transfer and Advancement Act (NTTAA) and
1 CFR Part 51

I. General Information for ACI That Only Burn Wood Wastes, Yard Wastes,
and Clean Lumber

A. Executive Summary

The EPA is proposing to consolidate the existing provisions
governing Air Curtain Incinerators (ACI) and placing them in one new
rule subpart. Pursuant to Clean Air Act (CAA) section 129(g)(1)(C), the
EPA has previously established in various CAA section 129 regulations
opacity limitations and associated monitoring and recordkeeping
requirements for ACI that

[[Page 13546]]

only burn wood wastes, yard wastes, clean lumber, or any mixture of
these three materials. In this rulemaking, the EPA is proposing to
consolidate the opacity limitations and associated monitoring,
recordkeeping, and reporting requirements that currently exist across
CAA section 129 regulations for four different solid waste incineration
unit source categories: large municipal waste combustors (LMWC), small
municipal waste combustors (SMWC), commercial and industrial solid
waste incinerators (CISWI), and other solid waste incinerators (OSWI).
The EPA is also proposing to remove the CAA title V permitting
requirement for this type of ACI that is subject to title V under
current CAA section 129 regulations and are not located at title V
major sources or subject to title V for other reasons. In addition to
the proposed actions for ACI that only burn wood wastes, yard wastes,
and clean lumber, or any mixture of these three materials, the EPA is
soliciting comment on the definition of ``municipal waste combustion
unit'' in the OSWI rules. The EPA anticipates that this rule will have
cost savings due to the removal of title V permit requirements for ACI
that only burn wood wastes, yard wastes, and clean lumber. The EPA is
proposing this action to provide relief regarding the overly burdensome
permit process for States as they work to utilize ACI for natural
disasters clean up and to mitigate wildfires. This proposal would make
it easier for the EPA's regulatory partners to understand and comply
with the regulations under CAA section 129 and speed up the permitting
process across the country, while still meeting all statutory
requirements under the CAA.

B. Does this proposed action apply to me?

Sources potentially affected by this proposed rulemaking are ACI
that only burn wood wastes, yard wastes, clean lumber, or any mixture
of these three materials.
Wood waste refers to untreated wood and untreated wood products,
including tree stumps (whole or chipped), trees, tree limbs (whole or
chipped), bark, sawdust, chips, scraps, slabs, millings, and shavings.
Wood waste does not include yard waste (defined later in this
paragraph); construction, renovation, and demolition wastes; clean
lumber (defined later in this paragraph); treated wood or treated wood
products such as wood products that have been painted, pigment-stained,
or pressure treated by compounds such as chromate copper arsenate,
pentachlorophenol, or creosote; or manufactured wood products that
contain adhesives or resins (e.g., plywood, particle board, flake
board, and oriented strand board).\1\ Yard waste refers to grass, grass
clippings, bushes, shrubs, and bush and shrub clippings from
residential, commercial/retail, institutional, or industrial sources as
part of maintaining yards or other private or public lands. Yard waste
does not include construction, renovation, demolition wastes; and clean
lumber, which is exempt from the definition of municipal solid waste
(MSW) in this section. Clean lumber refers to wood or wood products
that have been cut or shaped and includes wet, air-dried, and kiln-
dried wood products. Clean lumber does include treated wood and treated
wood products.\2\
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\1\ See, e.g., 40 CFR 60.2977.
\2\ See, e.g., 40 CFR 60.2977.
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If you have questions regarding the applicability of this action to
a particular entity, consult the person listed in the FOR FURTHER
INFORMATION CONTACT section.

C. Where can I get a copy of this document and other related
information?

In addition to being available in the docket, an electronic copy of
this document is available on the internet. Following signature by the
Administrator, the EPA also will post a copy of this document to
<a href="http://www.epa.gov/stationary-sources-air-pollution/air-curtain-incinerators-only-burn-wood-wastes-yard-wastes-and">www.epa.gov/stationary-sources-air-pollution/air-curtain-incinerators-only-burn-wood-wastes-yard-wastes-and</a>.
A memorandum for ACI that only burn wood wastes, yard wastes, and
clean lumber showing the rule edits that would be necessary to
incorporate the changes to 40 CFR parts 60 and 62 is available in the
docket for this action (Docket ID No. EPA-HQ-OAR-2025-0068). Following
signature by the EPA Administrator, the EPA also will post a copy of
this document to <a href="http://www.epa.gov/stationary-sources-air-pollution/air-curtain-incinerators-only-burn-wood-wastes-yard-wastes-and">www.epa.gov/stationary-sources-air-pollution/air-curtain-incinerators-only-burn-wood-wastes-yard-wastes-and</a>.

II. Background for ACI That Only Burn Wood Wastes, Yard Wastes, and
Clean Lumber

A. What is the Agency's statutory authority for taking this action?

Section 129 of the CAA requires the EPA to establish standards for
solid waste incineration units. Such standards include emission
limitations for new sources and guidelines for existing sources
pursuant to CAA section 129 and 111.\3\ CAA section 129(g)(1) defines a
``solid waste incineration unit'' as ``a distinct operating unit of any
facility which combusts any material from commercial or industrial
establishments or the general public (including single and multiple
residences, hotels, and motels)''; however, ``solid waste incineration
units'' do not include ``air curtain incinerators provided that such
incinerators only burn wood wastes, yard wastes and clean lumber and
that such air curtain incinerators comply with opacity limitations to
be established by the Administrator by rule.'' \4\ Because ACI that
only burn these materials and comply with the opacity limitations
established by the EPA under CAA section 129(g)(1)(C) are not solid
waste incineration units, they are not subject to standards for solid
waste incineration units established under CAA sections 129(a) and (b),
and the only provisions in the existing section 129 regulations that
apply to these ACI are the opacity limitations and the associated
requirements established under CAA section 129(g)(1)(C).
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\3\ 42 U.S.C. 7429(a)(1)(A) (citing 42 U.S.C. 7411).
\4\ Id. 7429(g)(1), (g)(1)(C).
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Pursuant to CAA section 129(g)(1)(C), the EPA has previously
established in various CAA section 129 regulations the opacity
limitations and associated monitoring and recordkeeping requirements
for ACI that only burn wood wastes, yard wastes, clean lumber, or any
mixture of these three materials. In this rulemaking, the EPA is
proposing to consolidate these requirements by removing them from
existing CAA section 129 regulations and placing them in a new rule
subpart specific to this type of ACI (40 CFR part 60 subpart Ca).
The EPA is also proposing to remove the CAA title V permitting
requirement for such ACI to the extent they that are currently subject
to title V under existing CAA section 129 regulations but are not
located at title V major sources or subject to title V for other
reasons.\5\ In 2024 the EPA amended existing Other Solid Waste
Incinerator (OSWI) CAA section 129 regulations to remove the title V
permitting requirement for such ACI,\6\ and in 2026 we finalized new
LMWC New Source Performance Standards (NSPS) and did the same.\7\ The
remaining section 129 regulations that still subject such ACI to the
title V permitting requirement include CISWI and SMWC rules as well

[[Page 13547]]

as the LWMC Federal Plan. The EPA is proposing to remove this
requirement from these existing regulations and clarify in the proposed
new subpart Ca that title V permits are not required for any such ACI
provided that it is not a major source or subject to title V for other
reasons. Unless provided otherwise by law, an agency may change
existing positions (e.g., reconsider, revise, or rescind prior actions)
so long as it acknowledges the change in position, provides a reasoned
explanation for the change, and takes any serious reliance interests
into account.\8\ The EPA explains below in this section and in more
detail in section III.B of this document why it had previously required
title V permitting for ACI that only burn wood wastes, yard wastes, and
clean lumber and why it is proposing to remove this requirement for
such ACI. The EPA is not aware of any serious reliance interest
engendered by the current title V permitting requirement for these ACI
and is soliciting comment on whether there is any such interest that
the EPA must consider in removing this requirement (ACI-0).
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\5\ The proposed removal would not cover ACI for which such
removal was finalized in the 2026 LMWC new source performance
standards and emissions. 91 FR 11802 (Mar. 10, 2026).
\6\ 89 FR 27392 (Apr. 17, 2024), as amended November 04, 2024.
\7\ 91 FR 11802 (Mar. 10, 2026).
---------------------------------------------------------------------------

Section 129(e) of the CAA requires that ``solid waste incineration
units'' operate pursuant to a title V permit.\9\ Section 502(a) of the
CAA also requires title V permits for sources subject to regulation
under CAA section 111,\10\ and the EPA's regulation at 40 CFR 70.3(a)
clarifies that title V permitting is required for ``[a]ny source,
including an area source, subject to a standard, limitation, or other
requirement under [CAA] section 111.'' As explained in section III.B of
this document, the title V requirements for ``solid waste incineration
units'' under CAA section 129(e) do not apply to ACI that only burn
wood wastes, yard wastes, clean lumber, or any mixture of these three
materials because these ACI are not ``solid waste incineration units''
as defined in CAA section 129(g)(1). The EPA also did not invoke CAA
section 129(e) as the basis for requiring title V permitting for such
ACI in the existing section 129 regulations.\11\ Rather, the EPA
explained that the opacity limitations for such ACI were established
pursuant to CAA sections 111 and 129, and because these ACI are sources
subject to regulation under CAA section 111, they must operate with
title V permits as required by CAA section 502(a).\12\ For the reasons
explained in section III.B of this document, the EPA now believes that
the opacity limitations established for these ACI are not CAA section
111 standards within the scope of section 502(a) and 40 CFR 70.3(a).
Moreover, CAA section 502(a) authorizes the Administrator to exempt
nonmajor source categories from title V through rulemaking.\13\ The EPA
also finds, in the alternative, that title V permitting is
unnecessarily burdensome for these ACI and proposes to exempt them by
rule from title V requirements on that basis.
---------------------------------------------------------------------------

\8\ See, e.g., FDA v. Wages & White Lion Invs., L.L.C., 145 S.
Ct. 898, 917 (2025); Encino Motorcars v. Navarro, 579 U.S. 211, 221
(2016); FCC v. Fox Television Stations, Inc., 556 U.S. 502, 515
(2009).
\9\ 42 U.S.C. 7429(e).
\10\ 42 U.S.C. 7661a(a).
\11\ See e.g., 76 FR 15741 (Mar. 21, 2011).
\12\ Id.
\13\ 42 U.S.C. 7661a(a).
---------------------------------------------------------------------------

A. What is the regulatory history for this action?

As mentioned above, ACI that only burn wood wastes, yard wastes,
clean lumber, or any mixture of these materials, are currently
addressed in separate CAA section 129 regulations for four different
solid waste incineration unit source categories: LMWC, SMWC, CISWI, and
OSWI. These CAA section 129 regulations are as follows:
<bullet> 40 CFR part 60 subpart Cb--Emission Guidelines (EG) and
Compliance Times for Large Municipal Waste Combustors That are
Constructed on or Before September 20, 1994;
<bullet> 40 CFR part 60 subpart Eb--Standards of Performance for
Large Municipal Waste Combustors for Which Construction is Commenced
After September 20, 1994, or for Which Modification or Reconstruction
is Commenced After June 16, 1996;
<bullet> 40 CFR part 60 subpart VVVV--Standards of Performance for
Large Municipal Waste Combustors;
<bullet> 40 CFR part 60 subpart WWWW--Emission Guidelines and
Compliance Times for Large Municipal Waste Combustors Constructed on or
Before January 23, 2024;
<bullet> 40 CFR part 60 subpart AAAA--Standards of Performance for
Small Municipal Waste Combustion Units for Which Construction is
Commenced After August 30, 1999, or for Which Modification or
Reconstruction is Commenced After June 6, 2001;
<bullet> 40 CFR part 60 subpart BBBB--Emission Guidelines and
Compliance Times for Small Municipal Waste Combustors Constructed on or
Before August 30, 1999;
<bullet> 40 CFR part 60 subpart CCCC--Standards of Performance for
Commercial and Industrial Solid Waste Incineration Units;
<bullet> 40 CFR part 60 subpart DDDD--Emission Guidelines and
Compliance Times for Commercial and Industrial Solid Waste Incineration
Units;
<bullet> 40 CFR part 60 subpart EEEE--Standards of Performance for
Other Solid Waste Incineration Units;
<bullet> 40 CFR part 60 subpart FFFF--Emission Guidelines and
Compliance Times for Other Solid Waste Incineration Units;
<bullet> 40 CFR part 62 subpart FFF--Federal Plan Requirements for
Large Municipal Waste Combustors Constructed on or Before September 20,
1994;
<bullet> 40 CFR part 62 subpart III--Federal Plan Requirements for
Commercial and Industrial Solid Waste Incineration Units That Commenced
Construction on or Before November 30, 1999;
<bullet> 40 CFR part 62 IIIa--Federal Plan Requirements for
Commercial and Industrial Solid Waste Incineration Units That Commenced
Construction on or Before June 4, 2010, and Have Not been Modified or
Reconstructed Since August 7, 2013; and
<bullet> 40 CFR part 62 subpart JJJ--Federal Plan Requirements for
Small Municipal Waste Combustion Units Constructed on or Before August
30, 1999.
The provisions governing ACI that only burn wood wastes, yard
waste, clean lumber, or any mixture of these materials, are, for the
most part, the same or substantially similar across these regulations
except for minor differences in definitions of an ACI and averaging
times for determining compliance with applicable emissions limits.
These differences are discussed further in section III.A of this
document. Table 1 provides a summary of ACI definitions, applicability
and exemption language, and opacity limits and averaging times across
these rules.

[[Page 13548]]

Table 1--Current ACI Unit Definitions, Applicability/Exemptions, and
Opacity Limits Across Different CAA Section 129 Rule Provisions
------------------------------------------------------------------------
Opacity limits
Category Definition of Applicability and averaging
ACI unit times
------------------------------------------------------------------------
LMWC................. Incinerator ACI located at 10 percent
that operates a plant that opacity limit
by forcefully meets the (6-minute
projecting a capacity average).
curtain of air specifications 35 percent
across an open (greater than opacity limit
chamber or pit 250 tons per (6-minute
in which day (tpd) average)
burning municipal during 30-
occurs. solid waste) minute startup
Incineration and combusts period.
of this type 100 percent Limit applies
can be yard waste are at all times
constructed exempt from except during
above or below all provisions malfunction.
ground and except opacity Malfunction
with or limit, testing periods are
without procedures, limited to 3
refractory and reporting hours per
walls and and occurrence.
floor. recordkeeping.
SMWC................. Incinerator ACI that 10 percent
that operates combust 100 opacity limit
by forcefully percent yard (6-minute
projecting a waste and meet average).
curtain of air capacity 35 percent
across as open specifications opacity limit
chamber or for SMWC (at (6-minute
open pit in least 35 tpd average)
which municipal during 30-
combustion solid waste minute startup
occurs. and no more period.
Incinerators than 250 tpd Malfunctions
of that type municipal exempted, but
can be solid waste) not to exceed
constructed are only 3 hours.
above or below required to
ground with or meet opacity
without limits,
refractory testing
walls and procedures,
floor. and
recordkeeping
and reporting
requirements.
CISWI................ Incinerator ACI located at 10 percent
that operates commercial and opacity limit
by forcefully industrial (average of
projecting a facilities three 1-hour
curtain of air that burn (1) blocks
across an open 100 percent consisting of
chamber or wood waste; ten 6-minute
open pit in (2) 100 average
which percent clean opacity
combustion lumber; or (3) values).
occurs. 100 percent 35 percent
Incinerators mixture of opacity limit
of this type only wood (average of
can be waste, clean three 1-hour
constructed lumber, and/or blocks
above or below yard waste are consisting of
ground with or only required ten 6-minute
without to meet average
refractory opacity opacity
walls and limits, values) during
floor. testing 30-minute
procedures, startup
and period.
recordkeeping Periods of
and reporting malfunction
requirements. are not
exempt.
OSWI................. Incinerator (A) Very small 10 percent
that operates MWC opacity limit
by forcefully subcategories: (6-minute
projecting a ACI that burn average).
curtain of air less than 35 35 percent
across an tpd of only opacity limit
open, (1) 100 (6-minute
integrated percent wood average)
combustion waste; (2) 100 during 30-
chamber (fire percent clean minute startup
box) or open lumber; (3) period.
pit or trench 100 percent Limits apply at
(trench yard waste; all times
burner) in and (4) 100 except during
which percent malfunction.
combustion mixture of
occurs. only wood
waste, clean
lumber, and/or
yard waste
collected from
the general
public and
from
residential,
commercial,
institutional,
and industrial
sources.
(B)
Institutional
Waste
Incineration
Unit
subcategories:
ACI located at
institutional
facilities
that only burn
(1) 100
percent wood
waste; (2) 100
percent clean
lumber; (3)
100 percent
yard waste;
and (4) 100
percent
mixture of
only wood,
clean lumber,
and/or yard
waste
generated at
that facility.
ACI as
described in
(A) and (B)
above are only
required to
meet opacity
limits,
testing
procedures,
and
recordkeeping
and reporting
requirements.
------------------------------------------------------------------------

There are also differences among the current title V permitting
requirements for this type of ACI across CAA section 129 rule subparts.
For example, the OSWI rules do not require a title V permit for ACI
that only burn wood wastes, yard wastes, and clean lumber if they ``are
not otherwise required to obtain a title V permit.'' \14\ Similarly,
the EPA removed the title V permit requirement for ACI that only burn
wood wastes, yard wastes, and clean lumber and are not located at a
major source or subject to title V for other reasons in the 2026 LMWC
final rule.\15\ However, similar ACI, such as those subject to the
CISWI or SMWC rules and LMWC Federal Plan, must obtain a title V permit
under current regulations.\16\
---------------------------------------------------------------------------

\14\ 40 CFR 60.2966(b); see also 40 CFR 70.3(a)(1) (requiring
title V permitting for any ``major source''); 40 CFR 70.2 (defining
a ``major source'' under title V).
\15\ See 91 FR 11802 (Mar. 10, 2026).
\16\ See, e.g., 40 CFR 60.2242, 62.15020(k).
---------------------------------------------------------------------------

In this rulemaking, the EPA is proposing to consolidate regulatory
provisions governing ACI that only burn wood wastes, yard wastes, clean
lumber, or any mixture of these materials, by removing them from
existing CAA section 129 regulations and placing them in a new rule
subpart specific to this type of ACI. (40 CFR part 60 subpart Ca).
Also, because these ACI are materially indistinguishable regardless of
which CAA section 129 source category they are currently regulated
under and therefore need to be treated in a consistent manner, the EPA
is proposing to remove the title V permitting requirement for these ACI
that are currently regulated under the CAA section 129 regulations for
CISWI, SMWC, and the LMWC Federal Plan. This is consistent with the
EPA's 2024 final rule that removed title V permitting for these ACI in
the existing CAA section 129 OSWI regulations \17\ and its 2026
amendments to the LMWC NSPS and EG.\18\ For the new subpart Ca, the EPA
is proposing that title V permits are not required provided that the
ACI is not a major source or subject to title V for other reasons.
---------------------------------------------------------------------------

\17\ 89 FR 27392 (Apr. 17, 2024).
\18\ See 91 FR 11802 (Mar. 10, 2026).
---------------------------------------------------------------------------

Please note that the proposed new subpart Ca does not directly
apply to existing sources subject to state plans that implement CAA
section 129 EGs. However, if finalized, States that currently require
title V permitting in their state plans would be able to revise their
plans to remove the title V permitting requirement for this type of
ACI.

III. Proposed Actions for ACI That Only Burn Wood Wastes, Yard Wastes,
and Clean Lumber

A. Proposed Consolidation of the Existing Opacity Limits for ACIs That
Only Burn Wood Wastes, Yard Wastes, and Clean Lumber

The EPA is proposing to consolidate requirements for ACI that only
burn wood wastes, yard wastes, clean lumber, or any mixture of these
materials, by removing them from existing CAA section 129 regulations
and placing them in a new rule subpart specific to

[[Page 13549]]

this type of ACI, 40 CFR part 60 subpart Ca. The proposed subpart Ca
includes certain consolidated changes as described below.
The EPA is proposing a single definition for any ACI that burns
only wood wastes, yard wastes, clean lumber, or any mixture of these
materials. In the CAA section 129 rules governing LMWC, SMWC, and
CISWI, an ACI is defined as an ``incinerator that operates by
forcefully projecting a curtain of air across an open chamber or pit in
which burning occurs. Incineration of this type can be constructed
above or below ground and with or without refractory walls and floor.''
\19\ The OSWI rules define ACI slightly differently as an ``incinerator
that operates by forcefully projecting a curtain of air across an open,
integrated combustion chamber (fire box) or open pit or trench (trench
burner) in which combustion occurs.'' \20\
---------------------------------------------------------------------------

\19\ 40 CFR 60.51b, 60.1940, 60.2875; Table 1 of this document.
\20\ 40 CFR 60.2977, 60.3078; see also Table 1 of this document.
---------------------------------------------------------------------------

We are proposing to adopt the OSWI regulation definition in the new
subpart Ca for the following reasons. First, this definition
specifically includes fire box and trench burner unit types that are
commonly used for cleanup and disposal of wood wastes, yard wastes, and
clean lumber while not excluding other potential types of units.
Second, the part of the ACI definition in the CISWI, LMWC, and SMWC
rules that the unit ``can be constructed above or below ground and with
or without refractory walls and floor'' appears redundant (e.g.,
construction can only be above or below ground--there is no third
choice); without this phrase, ACI can still be constructed either above
or below ground. Please note that the proposed definition is
independent of unit design capacity and type of facility that owns or
operates the unit, and so the choice of definition is not intended to
and should not result in material differences in applicability or
requirements imposed. We solicit comment on the proposed definition of
ACI (ACI-1).
The proposed new subpart Ca would consolidate existing opacity
limitations during periods of regular operation for this type of ACI
and during the startup period of the unit. The opacity limits in the
new subpart Ca would be the same as those across all existing CAA
section 129 regulations (i.e., 10 percent opacity during regular
operation and 35 percent opacity during startup).\21\ This proposal
merely consolidates these longstanding opacity limitations for clarity
and administrability and does not reopen them for comment.
---------------------------------------------------------------------------

\21\ See, e.g., 40 CFR 60.1920, 60.2860, 60.56b, 60.3066; Table
1 of this document.
---------------------------------------------------------------------------

The EPA also proposes to create a single set of opacity measurement
averaging time requirements that are clear and consistent with the
methodologies of EPA Method 9, a compliance determination method for
opacity that is required in the LMWC, SMWC, OSWI, and CISWI rules.\22\
We are proposing that compliance with the opacity limit will be based
on 6-minute averages, as provided in the 40 CFR part 60 General
Provisions at 40 CFR 60.11(b). This is the current requirement in all
CAA section 129 rules except the CISWI rules, which require that the
determination be based on ``three 1-hour blocks consisting of ten 6-
minute average opacity values.'' \23\ Under 40 CFR 60.11(b), ``the
minimum total time of observations shall be 3 hours'' and the 3 hours
are comprised of 30 6-minute averages. While the minimum observation
period under the CISWI rules is also 3 hours, CISWI requires averaging
the ten values for each 1-hour block and then averaging the three 1-
hour block values, making the final value less representative of the
individual 6-minute average values and in turn providing less
confidence in determining whether there is an opacity concern, which
would be indicative of a combustion issue that needs to be addressed.
We did not find in the CISWI rule records an explanation for why the
EPA chose to depart from 40 CFR 60.11(b) or why the averaging method in
CISWI rules differ from other CAA section 129 rules.\24\ As mentioned
earlier in this preamble, the purpose of this proposed rulemaking is to
have one set of requirements for all ACI that only burn wood wastes,
yard wastes, clean lumber, or a mixture thereof. Because all the other
rules follow 40 CFR 60.l1(b), we are proposing to apply the averaging
requirement in 40 CFR 60.11(b) in the proposed consolidated new rule
subpart Ca. We solicit comment on these proposed averaging time
requirements (ACI-2).
---------------------------------------------------------------------------

\22\ See, e.g., 65 FR 76355 (Dec. 6, 2000); 60 FR 65419 (Dec.
19, 1995); 84 FR 15853 (Apr. 16, 2019), 70 FR 74892 (Dec. 16, 2005).
\23\ See, e.g., NSPS CCCC (40 CFR 60.2125(i)).
\24\ See Docket ID No. EPA-HQ-OAR-2003-0119.
---------------------------------------------------------------------------

In addition to creating a single set of averaging time
requirements, the EPA is proposing to include text clarifying the
opacity monitoring requirements. One of these clarifications describes
how compliance is demonstrated when conducting opacity measurements;
this clarification is consistent with our discussion on averaging times
above. This clarification is especially needed for periods of startup,
as the startup period is only 30 minutes. The EPA has previously
received questions on how owners and operators are supposed to comply
with 40 CFR 60.8 during the startup period, as 40 CFR 60.8 requires
three test runs. The additional regulatory text would clarify that
owners and operators only need to make observations for 30 minutes to
demonstrate compliance during startup. We also propose to add a cross-
reference to 40 CFR 60.11 for performance tests, as this section of the
General Provisions provides instructions for conducting opacity
measurements.
Currently, the LMWC, CISWI, and OSWI rules require an annual
performance test, which must be conducted within 12 months following
the date of the previous test.\25\ However, the SMWC rule's required
annual performance test must be conducted ``no more than 13 months
following the date of the previous test.'' \26\ To maintain consistency
across ACI within the new subpart, we are proposing to require that the
annual performance tests must be conducted within 12 months of the date
of the previous test. We solicit comment on the proposed timeframe for
these annual performance tests (ACI-3).
---------------------------------------------------------------------------

\25\ See NSPS Eb (40 CFR 60.58b(l)(3)), NSPS CCCC (40 CFR
60.2255(c)), and NSPS EEEE (40 CFR 60.2972(c)).
\26\ See NSPS AAAA (40 CFR 60.1445(a)).
---------------------------------------------------------------------------

Currently, the OSWI rules state: ``If the air curtain incinerator
has been out of operation for more than 12 months following the date of
the previous test, then the owner or operator must conduct a test for
opacity upon startup of the unit.'' \27\ However, this language does
not appear in the CISWI, LMWC, or SMWC rules. Therefore, the EPA is
proposing to include in the new subpart Ca a provision similar to that
in the OSWI rules but with further clarification. Specifically, the EPA
is proposing that any ACI that is not in operation at the time the
annual test is due (12 months from the previous test) is not required
to conduct a test for opacity at that time. Without this language,
owners and operators could assume that they must start up their unit to
conduct annual testing, which would be an unnecessary burden for the
owner or operator and would tend to increase, rather than control,
emissions at a non-operating unit--a counterintuitive result with no
environmental benefit. Therefore, we are proposing to delay testing
until the next startup for any ACI that is not operating at the time of
scheduled testing. Specifically, the proposed new subpart Ca would
state:

[[Page 13550]]

``If the air curtain incinerator is not operating at the time that the
annual test would be required under paragraph (c) of this section, you
may delay the annual test until the next day you operate the unit.'' We
solicit comment on this proposed requirement (ACI-4).
---------------------------------------------------------------------------

\27\ See NSPS EEEE (40 CFR 60.2972(d)).
---------------------------------------------------------------------------

The EPA is also proposing to require the completion of an initial
performance test within 60 days of the initial startup. Currently, the
timeline for conducting the initial performance test in all the
different CAA section 129 regulations is within 60 days after reaching
the operational charge rate but no later than 180 days after initial
startup.\28\ Since the performance test is used to demonstrate
compliance, allowing up to 180 days of startup for performance testing
seems unreasonably long in this case. The ``up to 180 days'' is a
default maximum timeframe provided in the General Provisions, which may
be necessary for complicated sources with multiple air pollution
control devices that may need time to fully begin operations and work
through issues that can occur during initial startup. This is often
referred to as a shakedown period. During the shakedown period, sources
generally ramp up operations over time to protect the unit against
operational problems like thermal stress, overheating, and leaks. We do
not expect ACI that only burn wood wastes, yard wastes, and clean
lumber, or mixtures of these materials, and are subject only to opacity
limits, to require a long shakedown period. Such ACI are less
complicated than other sources that are required to conduct performance
testing, and as such, we would expect that these units can reach their
operational charge rate not long after startup; therefore, we expect
that these units should be able to conduct initial performance tests
within 60 days of startup.
---------------------------------------------------------------------------

\28\ See NSPS Eb (40 CFR 60.58b(l)(2)), NSPS CCCC (40 CFR
60.2255(b)), and NSPS EEEE (40 CFR 60.2972(b)), which reference 40
CFR 60.8 for conducting the initial performance test and NSPS AAAA,
which states the same timeframe in 40 CFR 60.1445(a).
---------------------------------------------------------------------------

This proposed rulemaking also includes initial notification
requirements. These would require the submission of an initial
notification of startup of this type of ACI, location of the ACI unit,
initial startup date, and types of materials burned in the ACI.
Previous notification requirements for this type of ACI did not include
the location of the ACI unit. We are proposing this requirement because
we believe it would be helpful for the EPA, State, and local
authorities to maintain an inventory of where these units are located,
particularly given the proposed removal of title V permit requirements
detailed in section III.B of this document. We solicit comment on these
proposed initial notification requirements (ACI-5).
This rulemaking also proposes recordkeeping and reporting
requirements for initial and annual opacity tests for this type of ACI.
For such ACI currently regulated under the OSWI rules, owners and
operators must keep records of these opacity tests in either a paper
copy or computer-readable (e.g., electronic) format for at least 5
years.\29\ These records must be kept on site for at least 2 years but
then may be kept off site for the remaining 3 years. These test results
must be submitted to the Administrator (as paper or electronic copy).
For initial opacity tests, results must be submitted within 60 days of
the test. For annual opacity tests, results must be submitted within 12
months following the previous report. The recordkeeping and reporting
requirements for this type of ACI regulated under the CISWI rules are
identical to those in the OSWI rules, with the exception of requiring
records of these opacity tests be kept on site for the entire 5-year
recordkeeping period.\30\ Like units regulated under CISWI, this type
of ACI regulated under the LMWC and SMWC rules are required to keep
records (paper or electronic copy) of these opacity tests on site for 5
years.\31\ However, opacity test results are to be submitted to the
Administrator by February 1 of the following year, rather than 60 days
from the initial test for initial reports, or 12 months from submittal
of the previous test for annual reports. In this case, the degree of
flexibility afforded to owners and operators of these ACI for
compliance with this reporting requirement could vary greatly depending
on when during the calendar year an initial opacity test is performed.
For this proposed rulemaking, we are basing the recordkeeping and
reporting requirements on those in the OSWI rules, as we believe the
language provides the greatest degree of specificity for these
respective requirements. We solicit comment on the proposed
recordkeeping and reporting requirements for these ACI (ACI-6).
---------------------------------------------------------------------------

\29\ See 40 CFR 60.3068.
\30\ See 40 CFR 60.2870.
\31\ See 40 CFR 60.59b(e) and 60.1930, respectively.
---------------------------------------------------------------------------

B. Proposed Removal of Existing Title V Requirements for ACI That Only
Burn Wood Wastes, Yard Wastes, and Clean Lumber

We are proposing to remove the title V permitting requirements for
ACI that only burn wood wastes, yard wastes, clean lumber, or any
mixture of these materials, that were previously covered by CAA section
129 CISWI and SMWC regulations as well as the LWMC Federal Plan,
provided they are not otherwise subject to title V.\32\ The EPA made
the same amendments in the revised OSWI rule in 2024 \33\ and the LMWC
rule in 2026.\34\
---------------------------------------------------------------------------

\32\ CAA section 502(a) provides that the EPA cannot exempt
major sources from title V by rule. See 42 U.S.C. 7661a(a); 40 CFR
70.3(b)(1). This proposed rule also would not affect title V
applicability to any ACI currently subject to title V for other
reasons, as provided in CAA section 502(a) and 40 CFR 70.3(a).
\33\ See 89 FR 27392 (Apr. 17, 2024).
\34\ See 91 FR 11802 (Mar. 10, 2026).
---------------------------------------------------------------------------

The EPA is proposing to remove the title V permitting requirement
for this type of ACI for the following reasons. First, CAA section
129(e) and the EPA's title V regulation at 40 CFR 70.3(b)(1), which
require that each solid waste incineration unit operate with a title V
permit, do not by their terms apply to ACI that only burn wood wastes,
yard wastes, or clean lumber and that are subject to opacity
limitations established by the EPA. These ACI are not ``solid waste
incineration units'' as defined in CAA section 129(g)(1)(C) and are
therefore not subject to title V permitting under CAA section 129(e) or
40 CFR 70.3(b)(1).
Second, while CAA section 502(a) and the EPA's title V regulations
at 40 CFR 70.3(a)(2) require that sources subject to CAA section 111
standards operate with a title V permit, the opacity limits for ACI
that only burn wood wastes, yard wastes, clean lumber, or any mixture
of these materials, are not section 111 standards. As mentioned
earlier, the EPA had previously claimed that the opacity limits for
these ACI ``were established pursuant to CAA sections 111 and 129'' and
thereby triggered CAA section 502 requirement that sources subject to
regulation under CAA section 111 must operate with title V permits.\35\
However, the EPA now believes that prior assertion to be inaccurate for
the following reasons. First, the opacity limitations and related
requirements for these ACI were established under CAA section
129(g)(1)(C), which does not require the EPA to establish such opacity
limitations under CAA section 111. Second, while certain section 129

[[Page 13551]]

provisions require that standards be established pursuant to CAA
sections 111 and 129, it does not appear that the opacity limitations
for these ACI were established pursuant to any such section. For
example, CAA section 129(a) requires the EPA to establish standards
``pursuant to section [111] of this title and this section for each
category of solid waste incineration units.'' As noted above, because
these ACI are not solid waste incineration units, section 129(a) does
not apply to such ACI. Similarly, CAA section 129(a)(2) requires that
``standards applicable to solid waste incineration units'' promulgated
under section [111 and 129] shall reflect the maximum degree of
reduction in emissions of air pollutants listed under section (a)(4)
that the Administrator, taking into consideration the cost of achieving
such emission reduction, and any non-air quality health and
environmental impacts and energy requirements, determines is achievable
for new or existing units in each category.'' CAA section 129(a)(4), in
turn, provides that standards promulgated under sections 111 and 129
and ``applicable to solid waste incineration units shall'' include
opacity limits ``as appropriate.'' However, as noted above, ACI burning
only wood wastes, yard wastes, clean lumber, or mixtures thereof are
not solid waste incineration units under CAA section 129(g)(1)(C).
Therefore, the EPA is not required by CAA section 129(a)(2) and (4) to
establish opacity limits for such ACI units pursuant to sections 111
and 129. Nor is there any record showing that the opacity limits for
this type of ACI were established pursuant to sections 111 and 129 in
accordance with CAA section 129(a)(4). The EPA first established the
opacity limits for ACI that only burn yard wastes in 1995.\36\ The EPA
explained at the time that it was directed by CAA section 129 to
establish such opacity limits \37\ and that the limits ``are based on
levels achieved by well-designed and operated air curtain
incinerators.'' \38\ The EPA subsequently promulgated the same opacity
limits for ACI that only burn wood wastes and clean lumber.\39\ In
neither rulemaking did the EPA explain how the standards were
established pursuant to CAA sections 111.
---------------------------------------------------------------------------

\35\ See 76 FR 15741 (Mar. 21, 2011).
\36\ See 60 FR 65387, 65425 (Dec. 19, 1995).
\37\ See 59 FR 48198, 48211 (Sept. 20, 1994).
\38\ See id. at 48223.
\39\ 65 FR 75338 (Dec. 1, 2000).
---------------------------------------------------------------------------

For the reasons stated above, we do not believe that the opacity
limitations established under CAA section 129(g)(1)(C) for ACI that
only burn wood wastes, yard wastes, clean lumber, or any mixture
thereof are CAA section 111 standards; therefore, these opacity
limitations do not trigger the title V permitting requirement for this
type of ACI.
Third, CAA section 502(a) authorizes the Administrator to
promulgate regulations to exempt non-major sources from the title V
permitting requirement if the Administrator finds, in his discretion,
that compliance with such requirement is impracticable, infeasible, or
unnecessarily burdensome. Such an exemption is not required in this
case because, as proposed above, the statute does not require title V
permitting for ACI that only burn wood wastes, yard wastes, clean
lumber, or any mixture thereof. Nevertheless, the EPA finds, in the
alternative, that compliance with title V permitting is unnecessarily
burdensome for this type of ACI. Under this alternative, even if it
were determined that such ACI are CAA section 111 standards subject to
title V permitting requirements under CAA section 502(a) and the EPA's
regulation at 40 CFR 70.3(a)(2), we would nevertheless exempt such
sources from title V requirements on that basis. During the prior CISWI
rulemakings, the EPA had acknowledged that it could exempt nonmajor
sources from title V permitting by making the necessary finding under
CAA section 502 but had declined to do so for these ACI because the EPA
had not made such finding for these ACI in other CAA section 129 rules
and believed that it was important to treat these ACI in the same
manner.\40\ As mentioned earlier, in 2024 the EPA amended existing OSWI
section 129 regulations to remove the title V permitting requirement
for such ACI.41 42 The EPA is treating these ACI in the same
manner by proposing to remove the title V permitting requirement for
units regulated under the remaining section 129 regulations that
currently require title V permitting for these ACI.
---------------------------------------------------------------------------

\40\ 76 FR 15704, 15741 (Mar. 21, 2011); 84 FR 15846, 15851
(Apr. 16, 2019).
\41\ 89 FR 27392 (Apr. 17, 2024); see also 89 FR 89928 (Nov. 14,
2024) (technical correction).
\42\ 89 FR 4243 (Jan. 23, 2024).
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The EPA has previously developed a four-factor balancing test in
determining under CAA section 502(a) whether compliance with title V is
``unnecessarily burdensome.'' These four factors are: (1) whether title
V permitting would result in significant improvements in compliance
with emission standards; (2) whether title V permitting would impose
significant burdens on the area source category; (3) whether the costs
are justified, taking into account potential gains; and (4) whether
there are existing enforcement programs in place sufficient to ensure
compliance.\43\ The EPA has historically also considered whether such
an exemption would adversely affect public health, welfare, or the
environment.\44\ In exercising the discretion conferred by statute, the
Administrator considers these factors in combination, and not every
factor must point in the same direction to support an exemption. As
explained below, the EPA considers and balances these same factors in
this action.
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\43\ 70 FR 75320, 75323 (Dec. 19, 2005); see U.S. Sugar Corp. v.
EPA, 830 F.3d 579, 647 (D.C. Cir. 2016).
\44\ See, e.g., 70 FR 75323 (Dec.19, 2005).
---------------------------------------------------------------------------

With respect to the first factor, the EPA does not believe that
title V permitting would result in significant improvements in
compliance with emission standards. One of the primary benefits of the
title V program is to compile and clarify, in a single document, the
various and complex regulations that apply to a facility in order to
improve compliance and thereby ``enable the source, states, EPA, and
the public to understand better the requirements to which the source is
subject, and whether the source is meeting those requirements.'' \45\
However, this benefit is not realized with respect to ACI that only
burn wood wastes, yard wastes, clean lumber, or mixtures thereof; these
ACI are subject only to opacity limitations and associated monitoring
recordkeeping and reporting requirements established under CAA section
129(g)(1)(C), and we are not aware that they are subject to any other
requirement under the CAA. Another way title V can improve compliance
is its requirement that ``[e]ach permit . . . shall set forth . . .
monitoring . . . requirements to assure compliance with the permit
terms and conditions.'' \46\ This rulemaking, however, would adopt and
consolidate the monitoring, recordkeeping and reporting requirements
for these ACI in the current CAA section 129 rules with some minor
variations as detailed previously in section III.A. of this document.
Specifically, opacity would be monitored according to EPA Method 9, a
long established and common practice for determining compliance with
opacity limits. The owners and operators of these sources would perform
an initial opacity test no later than 60 days after initial startup,
and annual opacity tests no later than 12 calendar months following the
date of

[[Page 13552]]

the previous test, unless the ACI is not operating at the time that the
annual test would be required. Owners and operators would submit the
results of each opacity test to the Administrator no later than 60
calendar days after the date of completing the test. Records of these
opacity tests would be kept in either paper copy or electronic format
for at least 5 years; they would be kept on site for at least 2 years,
then could be kept off site for the remaining 3 years. These
requirements have been adequate to ensure compliance with the ACI
opacity limits currently in the existing CAA section 129 regulations
for various source categories. Although title V requires submitting
reports of any required monitoring at least every 6 months, per 40 CFR
70.6(a)(3)(iii)(A), we do not think more frequent reporting is
necessary for purposes of ensuring compliance with one single opacity
limit. In light of the above, we believe that the proposed monitoring,
recordkeeping, and reporting requirements of this proposed rulemaking
would be sufficient to ensure compliance, and that title V would not
significantly improve compliance.
---------------------------------------------------------------------------

\45\ See 57 FR 32250, 32251 (July 21, 1992).
\46\ 42 U.S.C. 7661c(c); see also 40 CFR 70.6(c)(1).
---------------------------------------------------------------------------

Regarding the second factor, we believe that title V permitting
would impose significant burdens on the owners and operators of these
sources. Costs associated with initial application and annual fees for
a title V permit can vary depending on state permitting policies.\47\
The permitting process, which includes preparing and submitting the
permit applications, meeting with the permitting authorities and
subjecting their operations and permit application to public comment,
takes time and could potentially delay operations. Considering the
above, we believe that title V requirements would impose a significant
additional burden without corresponding health or environmental
benefit.\48\
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\47\ See, e.g., South Carolina title V fees: <a href="https://des.sc.gov/programs/bureau-air-quality/annual-fees-title-v-sources">https://des.sc.gov/programs/bureau-air-quality/annual-fees-title-v-sources</a>; Virginia
title V fees; <a href="https://www.deq.virginia.gov/laws-regulations/air/fees-under-the-air-pollution-control-law">https://www.deq.virginia.gov/laws-regulations/air/fees-under-the-air-pollution-control-law</a>; Florida title V fees:
<a href="https://floridadep.gov/air/permitting-compliance/content/title-v-fees">https://floridadep.gov/air/permitting-compliance/content/title-v-fees</a>; Oregon title V fees: <a href="https://www.oregon.gov/deq/aq/aqpermits/pages/tvrule.aspx">https://www.oregon.gov/deq/aq/aqpermits/pages/tvrule.aspx</a>.
\48\ Also, as explained in the 2024 final rule removing title V
permitting requirement from OSWI section 129 regulations, ``the EPA
has received feedback from several States indicating that the title
V permits are unnecessarily burdensome and expensive for States to
maintain for these ACIs.'' 89 FR 27394 (Apr. 17, 2024).
---------------------------------------------------------------------------

Regarding the third factor, we believe the title V permitting costs
and other burdens are not justified as we believe there would be
little, if any, potential gain in compliance from subjecting this type
of ACI to title V. It is likely that many ACI that burn exclusively
wood wastes, yard wastes, clean lumber, or mixtures thereof are
commonly located at facilities that would not otherwise require a title
V operating permit, such as land clearing operations in public or
private land and fuels treatment for wildfire prevention.\49\ State and
industry stakeholders have commented that the title V requirements for
these units are overly burdensome and costly, particularly in light of
the dependence on ACI units to mitigate natural disaster debris, such
as massive amounts of clean wood and vegetative waste for wildfire
mitigation and forest management, burning of storm-generated wood and
vegetative debris, and burning of land clearing debris. Several States
have commented that these ACI should not be required to obtain title V
permits because they are low-emitting and because permitting these ACI
is unnecessarily burdensome and expensive. Further, ACI that burn
exclusively wood wastes, yard wastes, clean lumber, or any mixtures
thereof are often used temporarily at the location of a natural
disaster or disaster prevention, not at facilities that are subject to
title V. As mentioned earlier in this preamble, the only requirements
for these ACI are opacity limitations and associated monitoring,
recordkeeping, and reporting requirements that we believe are adequate
to assure compliance. In light of the above, we conclude that the cost
of title V permitting is not justified as we do not anticipate any
potential gain in health and environmental outcomes from compliance by
these ACI with additional title V requirements.
---------------------------------------------------------------------------

\49\ See, e.g., 89 FR 27392, 27394 (Apr. 17, 2024).
---------------------------------------------------------------------------

Regarding the fourth factor, we believe there are existing
enforcement programs in place sufficient to ensure compliance with
opacity limits for these ACI. State and local authorities can monitor
compliance with these opacity limits and related requirements with
delegated authorities for implementing and enforcing CAA section 129
regulations; the EPA is aware of no indication that these section 129
delegated authorities are insufficient to assure compliance with these
requirements, which as mentioned above have been in place for a long
time and are common practices. Therefore, enforcement of these opacity
limits and related requirements through title V permitting is not
necessary.
Lastly, requiring title V permitting for these ACI could adversely
affect public health, welfare, or the environment by diverting
resources toward permitting activities unlikely to generate additional
health or environmental benefits. Since compliance with the opacity
limitations for these ACI can be adequately assured without title V, as
explained above, title V permitting would unnecessarily shift State
resources away from assuring compliance for major sources and
potentially reducing overall air program effectiveness. We therefore
find title V permitting to be unnecessarily burdensome for ACI that
only burn wood wastes, yard wastes, clean lumber, or any mixture
thereof, and that are not major sources or subject to title V
permitting requirements for another reason.
In sum, the title V requirements for ``solid waste incineration
units'' and sources subject to CAA section 111 standards do not apply
to ACI that only burn wood wastes, yard wastes, clean lumber, or any
combination thereof, because these ACI are not ``solid waste
incineration units'' under CAA section 129(g)(1) and the opacity
limitations established for these ACI are not CAA section 111
standards. We also find, in the alternative, that title V requirements
would be unnecessarily burdensome for this type of ACI. For the reasons
stated above, we propose to remove from CAA section 129 regulations any
existing title V permitting requirements for ACI that only burn wood
wastes, yard wastes, and clean lumber, and state in the new subpart for
this type of ACI that these ACI are not required to obtain a title V
operating permit, provided that they are not otherwise required to
obtain a title V operating permit.

IV. Summary of Cost, Environmental, and Economic Impacts for ACI That
Only Burn Wood Wastes, Yard Wastes, and Clean Lumber

This proposed rulemaking would consolidate the opacity limits and
associated monitoring, recordkeeping and reporting requirements that
currently exist across the OSWI, CISWI, LMWC, and SMWC rules for ACI
that only burn wood wastes, yard wastes, clean lumber, or any mixture
of these materials. The only additional cost that we anticipate is the
cost of the initial notification requirement for ACI that only burn
wood wastes, yard wastes, clean lumber, or any mixture of these
materials. However, consistent with the current OSWI and LMWC
rulemakings, we are proposing to remove title V requirements for ACI
that only burn wood wastes, yard wastes, clean lumber, or any mixture
of these materials. We anticipate that the removal of the title V
requirements would result in cost savings for such ACI that are not co-
located at facilities with CISWI and

[[Page 13553]]

SMWC units currently required to obtain a title V permit for these
types of ACI. We do not anticipate any changes to emissions because no
new emission standards are being set. With the removal of title V
permitting requirements and the likelihood of associated net cost
savings and the associated reduced overall cost of operation, there
could be an increase in ACI use. This potential increase in ACI use
could generate increased emissions. We are unable to quantify emissions
changes of this nature for this proposed rulemaking but anticipate that
they would be small, particularly given the retention of existing
opacity limits for these units. We anticipate net savings because the
cost of removing the title V requirements will outweigh any costs
associated with the initial notification requirement. Hence, we
anticipate that there will not be adverse economic impacts for those
entities that use these types of ACI.

V. Request for Comments on Proposed Rule for ACI That Only Burn Wood
Wastes, Yard Wastes, and Clean Lumber

We solicit comment on all aspects of this proposed action described
above. In addition to general comments on this proposed action, we are
soliciting comments on the following topics. A comment reference
indicator for each specific topic is provided (e.g., ACI-1, ACI-2,
etc.).
<bullet> Whether the existing title V permitting requirement for
ACI that only burn wood wastes, yard wastes, and clean lumber, of any
mixture thereof, has engendered any serious reliance interest that the
EPA must consider in removing this permitting requirement. (ACI-0).
<bullet> The definition of ACI as an ``incinerator that operates by
forcefully projecting a curtain of air across an open, integrated
combustion chamber (fire box) or open pit or trench (trench burner) in
which combustion occurs'' as discussed in section III.A of this
document. (ACI-1).
<bullet> The averaging time requirement that compliance for opacity
is based on 6-minute averages, as provided in the 40 CFR part 60
General Provisions at 40 CFR 60.11(b), as discussed in section III.A of
this document. (ACI-2).
<bullet> The timeframe that annual performance tests be conducted
within 12 months of the date of the previous test as discussed in
section III.A of this document. (ACI-3).
<bullet> The ability to delay an annual performance test until the
next startup of the unit if the ACI is not operating at the time that
the annual test is required as described in section III.A of this
document. (ACI-4).
<bullet> The initial notification requirement for this type of ACI
as described in section III.A of this document. (ACI-5).
<bullet> Recordkeeping and reporting requirements as described in
section III.A of this document. (ACI-6).

VI. Request for Comment on Revising the Definition of ``Municipal Waste
Combustion Unit'' in OSWI NSPS and EG

In addition to the proposed action on ACI that only burn wood
wastes, yard wastes, and clean lumber, or any mixture of these
materials, the EPA is soliciting comment on revising the definition of
``municipal waste combustion unit'' in the OSWI NSPS and EG to remove
the reference to ``pyrolysis/combustion units.'' In the preamble to the
2005 OSWI final rule, the EPA stated that ``pyrolysis/combustion units
(two chamber incinerators with a starved air primary chamber followed
by an afterburner to complete combustion)'' are considered OSWI units
but did not further elaborate.\50\ The EPA proposed in 2020 to modify
the definition of ``municipal waste combustion unit'' in the OSWI rules
to remove the reference to pyrolysis/combustion units. The EPA
published an advanced notice of proposed rulemaking on September 8,
2021 (86 FR 50296), to gather more details on pyrolysis/combustion
units, including how they are used, the inputs and products of the
processes, and emissions from these processes. In 2023, the EPA
proposed to withdraw the 2020 proposed definition change.\51\ To assist
with the resolution of this longstanding issue, we are soliciting
comment on whether removing the reference to ``pyrolysis/combustion
units'' from the definition of ``municipal waste combustion unit'' in
the OSWI rules is appropriate or not, along with supporting legal,
policy, and factual arguments for the commenter's recommended position.
(OSWI-1).
---------------------------------------------------------------------------

\50\ 70 FR 74876 and 74877 (Dec. 16, 2005).
\51\ 88 FR 36524 (June 5, 2023).
---------------------------------------------------------------------------

VII. General Information for Temporary Use of CISWI Units in Disaster
Recovery

A. Executive Summary

The EPA is proposing to allow the temporary use of incineration
units subject to CISWI regulations during disaster recovery without the
need to comply with CAA section 129 requirements. In 2005, the EPA
promulgated the OSWI NSPS (40 CFR part 60, subpart EEEE) and EG (40 CFR
part 60, subpart FFFF).\52\ Those regulations established CAA section
129 standards and associated requirements for OSWI units, and
authorized OSWI to combust debris from a disaster or emergency on a
temporary basis without having to comply with applicable CAA section
129 requirements. In this rulemaking, we are proposing to authorize
such temporary use for incinerators (including ACI) subject to CISWI
regulations by adding temporary-use provisions similar to those in the
OSWI regulations to existing Federal CISWI rule subparts. The EPA does
not anticipate any additional capital costs associated with this
proposal if finalized, only notification costs. This proposed action
works to permanently respond to States' request for more incinerators
to be available for disaster clean up. By proposing this action, the
EPA is working to streamline responses to natural disasters and
emergencies and to advance cooperative federalism.
---------------------------------------------------------------------------

\52\ 70 FR 74870 (Dec. 16, 2005).
---------------------------------------------------------------------------

B. Does this proposed action apply to me?

Categories and entities potentially affected by this proposed
rulemaking are those that operate incinerators (including ACI) subject
to CISWI NSPS (40 CFR part 60, subpart CCCC), Federal Plan (40 CFR part
62, subpart IIIa), or EG (40 CFR part 60, subpart DDDD) (hereinafter
collectively referred to as ``CISWI'' \53\). If you have questions
regarding the applicability of this action to a particular entity,
consult the person listed in the FOR FURTHER INFORMATION CONTACT
section.
---------------------------------------------------------------------------

\53\ As used in this notice, the term ``CISWI'' refers to this
collection of Federal regulations and not incinerators as defined by
the term ``CISWI'' in these regulations, and the term ``CISWI
units'' refers to incinerators subject to any one of these
regulations.
---------------------------------------------------------------------------

C. Where can I get a copy of this document and other related
information?

The EPA has established a docket for CISWI Temporary Use
Incinerator rulemaking under Docket ID No. EPA-HQ-OAR-2003-0119.
Following signature by the EPA Administrator, the EPA also will post a
copy of this document to <a href="https://www.epa.gov/stationary-sources-air-pollution/commercial-and-industrial-solid-waste-incineration-units-ciswi-new">https://www.epa.gov/stationary-sources-air-pollution/commercial-and-industrial-solid-waste-incineration-units-ciswi-new</a>.

VIII. Background for Temporary Use of CISWI Units in Disaster Recovery

A. What is the statutory authority for taking this action?

Section 129 of the CAA, entitled ``Solid Waste Combustion,''
requires the

[[Page 13554]]

EPA to develop and adopt NSPS and EG for solid waste incineration units
pursuant to CAA section 111.\54\ Section 111(b) of the CAA requires the
EPA to establish NSPS for new sources, and CAA section 111(d) requires
the EPA to establish procedures for States to submit plans for
implementing EG for existing sources. The EPA promulgates Federal plans
to regulate existing sources where there are no approved state plans.
---------------------------------------------------------------------------

\54\ CAA section 129(a)(1)(A), 42 U.S.C. 7429(a)(1)(A).
---------------------------------------------------------------------------

Section 129(a)(1) of the CAA identifies five categories of solid
waste incineration units and requires emissions standards for ``each
category of solid waste incineration unit.'' The five categories of
solid waste incineration units are as follows:
(1) Units with a capacity of greater than 250 tpd combusting
municipal waste;
(2) Units with a capacity equal to or less than 250 tpd combusting
municipal waste;
(3) Units combusting hospital, medical and infectious waste;
(4) Units combusting commercial or industrial waste;
(5) ``other categories of solid waste incineration units.''
While the CAA specifically describes four of the five listed
categories by the types of wastes burnt, it leaves unspecified the
``other categories of solid waste incineration units.'' As the EPA
observed during the development of standards for OSWI, Congress could
have unambiguously required OSWI to cover ``every other possible type
of incineration unit burning any type of solid waste'' but did not to
do so, thereby leaving to the EPA's discretion to delineate those
``other'' categories of solid waste incineration units.\55\ Based on
that authority, the EPA defined OSWI to include very small municipal
combustion units and institutional waste combustion incineration units.
The EPA analyzed and excluded various types of incinerators from being
subject to CAA section 129 standards; among those excluded are
incinerators when they are used on a temporary basis to combust debris
during disaster recovery. The EPA determined that some incinerators
``should be handled differently due to unusual circumstances (e.g.,
unique geographic locations or climatic factors, temporary emergency
use)'' that would render compliance with CAA section 129 rules
infeasible.\56\ Accordingly, the EPA excluded incinerators from
complying with CAA section 129 standards and associated requirements
when they are used to combust debris during disaster recovery.\57\ To
qualify for this exclusion, an incinerator ``must burn debris in an
area declared a State of Emergency by a local or State government, or
the President, under the authority of the Stafford Act, has declared
that an emergency or a major disaster exists in the area.'' \58\ In
addition, owners and operators must follow the notification
requirements in the temporary use provisions.\59\
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\55\ 70 FR 74870, 74875 (Dec. 16, 2005).
\56\ Id. at 74875.
\57\ 70 FR 74870 (Dec. 16, 2005).
\58\ OSWI NSPS (40 CFR 60.2969) and OSWI EG (40 CFR 60.3061).
\59\ Id.
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Currently, these temporary use provisions are codified in the
Federal OSWI regulations, and the EPA has realized that States need
more incinerators for emergency/disaster debris cleanup. Some States
have requested the temporary use of CISWI for such purposes; \60\ based
on the same authority and for the same reasons explained in the 2005
OSWI rule \61\ and here in section VIII.B. of this preamble, the EPA is
proposing to include similar temporary use provisions for disaster
recovery in CISWI regulations, thereby extending such temporary use to
incinerators at commercial and industrial facilities upon final
promulgation.
---------------------------------------------------------------------------

\60\ Abraczinskas, M. (2024). Request for Relief Concerning Air
Curtain Incinerator Use in the State of North Carolina. <a href="https://www.deq.nc.gov/media/46541/download?attachment">https://www.deq.nc.gov/media/46541/download?attachment</a>.
\61\ 70 FR 74875, 74879 (Dec. 16, 2005).
---------------------------------------------------------------------------

The proposed action does not affect the EPA's obligation under CAA
section 129(a)(1)(C) to establish standards for ``solid waste
incineration units combusting commercial and industrial wastes.'' This
action proposes to provide for the temporary use of incinerators that
normally burn commercial or industrial wastes to instead burn debris
(which is defined in the Webster Dictionary as remains of materials
broken or destroyed, in this case by a natural disaster or emergency)
during disaster recovery without having to comply with CISWI standards
established pursuant to CAA section 129(a)(1)(c); the temporary use
provisions do not apply to combustion of commercial and industrial
wastes (i.e., wastes generated by commercial and industrial facilities)
for which standards are required under CAA section 129(a)(1)(C). The
EPA, therefore, concludes that these incinerators that are normally
used at commercial and industrial facilities to burn commercial or
industrial wastes need not comply with CAA section 129 emission
standards and associated requirements for CISWI while they are used to
combust debris if they only burn non-hazardous debris and not waste
from normal operations at their commercial and industrial facilities
during the temporary use period.
Please note that while the EPA is proposing to amend the CISWI EG
(40 CFR part 60, subpart DDDD), along with the CISWI NSPS and Federal
plan, to include the temporary use provisions, the CISWI EG does not
directly apply to existing incinerators covered by that EG. However, if
finalized, States may revise their State plans implementing subpart
DDDD to add the temporary use provisions that would be in subpart DDDD,
thereby allowing their existing incinerators at commercial or
industrial facilities to be used temporarily for emergency/disaster
debris clean up without complying with their CAA section 129 standards
during that period.

B. What is the regulatory history for this action?

In 2005, the EPA promulgated the OSWI NSPS (40 CFR part 60, subpart
EEEE) and EG (40 CFR part 60, subpart FFFF).\62\ Those regulations
established CAA section 129 standards and associated requirements for
OSWI units; however, the regulations also allow temporary use of
incinerators to burn debris during disaster recovery or other
emergencies without complying with such standards. Because these OSWI
regulations are currently the only CAA section 129 regulations with
such temporary use provisions, only incinerators subject to the OSWI
NSPS or State plans implementing the OSWI EG may be used on a temporary
basis to combust debris from a disaster or emergency without complying
with CAA section 129 requirements during that period.
---------------------------------------------------------------------------

\62\ 70 FR 74870 (Dec. 16, 2005).
---------------------------------------------------------------------------

On January 24, 2025, President Trump issued Executive Order (E.O.)
14181 to expedite cleanup of the catastrophic wildfires in Los Angeles
County.\63\ The E.O. sparked renewed awareness of regulatory challenges
associated with disaster recovery, which have increased in both
intensity and costliness in recent years.\64\ During disaster cleanup,
frequently there is considerable excess organic waste that, if left,
would

[[Page 13555]]

decompose into more harmful organic air emissions than if combusted or
landfilled. Incinerators are useful tools for disaster or emergency
cleanup, as they can process large quantities of debris and are
considered safer and more environmentally sound than other remediation
options.\65\ When Hurricane Helene hit in September 2024, States and
municipalities expressed concern over smoke impacts from open burning
of waste and debris, and increased likelihood of wildfires.\66\ To
respond to the scale of the disaster and volume of debris generated,
the EPA's Regional offices and Office of Enforcement and Compliance
Assurance issued No Action Assurances to allow North Carolina and
Tennessee to use their CISWI ACI units to combust non-hazardous
disaster debris, as ACI can be easily mobilized to reduce waste volume
and minimize harmful environmental impacts.\67\ This situation
highlighted the need for additional available incinerator capacity for
States during disasters, beyond those that could be made available
under the Federal OSWI regulations. In this action, the EPA is
proposing to include temporary use provisions in the Federal CISWI
regulations similar to those in the Federal OSWI regulations,
increasing the incinerator capacity available to combust non-hazardous
disaster debris during disaster or emergency events. These provisions
were previously published by the EPA in a final agency action Interim
Final Rule (IFR); however, due to the conclusion of the hurricane and
wildfire seasons of 2025, the EPA is withdrawing the IFR and proposing
those provisions through a notice-and-comment rulemaking action. The
provisions propose to exclude incinerators subject to CISWI from CAA
section 129 requirements when they are used on a temporary basis to
combust debris from a disaster or emergency such as a tornado,
hurricane, flood, ice storm, high winds, or act of bioterrorism. Such
temporary use provisions are being proposed in the following CAA
section 129 regulations:
---------------------------------------------------------------------------

\63\ Executive Order 14181, Emergency Measures to Provide Water
Resources in California and Improve Disaster Response in Certain
Areas, 90 FR 8747 (Jan. 24, 2025).
\64\ Moore, A. Hurricane Helene's Aftermath Fuels Heightened
Wildfire Risk in Western North Carolina (2025). <a href="https://cnr.ncsu.edu/staging/2025/11/04/hurricane-helenes-aftermath-fuels-heightened-wildfire-risk-in-western-north-carolina/">https://cnr.ncsu.edu/staging/2025/11/04/hurricane-helenes-aftermath-fuels-heightened-wildfire-risk-in-western-north-carolina/</a>.
\65\ U.S. EPA. No Action Assurance for the Use of Air Curtain
Incinerators to Manage Debris Caused By Hurricane Helene in North
Carolina (2024), <a href="https://www.deq.nc.gov/media/46792/download?attachment">https://www.deq.nc.gov/media/46792/download?attachment</a>.
\66\ Id.
\67\ Id.
---------------------------------------------------------------------------

<bullet> 40 CFR part 60, subpart CCCC--Standards of Performance for
Commercial and Industrial Solid Waste Incinerations Units;
<bullet> 40 CFR part 60, subpart DDDD--Emission Guidelines and
Compliance Times for Commercial and Industrial Solid Waste Incineration
Units;
<bullet> 40 CFR part 62, subpart IIIa--Federal Plan Requirements
for Commercial and Industrial Solid Waste Incineration Units That
Commenced Construction on or Before June 4, 2010, and Have Not been
Modified or Reconstructed Since August 7, 2013
As discussed earlier in section VIII.A, the temporary use
provisions in the CISWI EG do not directly apply to existing sources.
However, following final rule promulgation, States may amend their
State plans implementing 40 CFR part 60, subpart DDDD to include these
temporary use provisions.

IX. Rationale for Temporary Use of CISWI Units in Disaster Recovery

A. Temporary Use of CISWI During Disaster Recovery

This rule proposes temporary use disaster recovery and emergency
provisions for the Federal CISWI regulations similar to those currently
in the Federal OSWI regulations. Under this proposal, like OSWI units,
CISWI units would not need to comply with their CAA section 129
emission standards and associated requirements while they are used to
combust debris as long as they follow the conditions for these
temporary use provisions. Specifically, the owners or operators of
CISWI units would be allowed to combust debris only in an area declared
a State of Emergency by a local or State government or where the
President, under the authority of the Stafford Act, has declared that
an emergency or a major disaster exists in the area. Under these
temporary use provisions, debris that could be combusted would be any
non-hazardous material that is the remains of something that is
destroyed, broken, or discarded as a result of a disaster or emergency
such as a tornado, hurricane, flood, ice storm, high winds, or act of
bioterrorism; and during the disaster recovery period, the CISWI unit
would not be burning waste from normal operations at their commercial
and industrial facilities. Also, owners and/or operators would follow
the notification requirements specified in the temporary use
provisions.
In addition, under the CISWI temporary use provisions, we are
proposing that control devices that have been installed to comply with
CISWI NSPS, CISWI Federal plan or a State plan implementing CISWI EG
would continue operation during temporary use status unless it is not
technically feasible to do so due to conditions in the disaster
recovery area; \68\ otherwise, these controls are already in place, and
they can minimize air pollution during the disaster recovery period
even if the CISWI are excluded from CAA section 129 standards and
associated requirements during that time. Examples of infeasibility to
operate include insufficient electricity to operate a control device,
lack of water to operate a wet scrubber or quench, and inability to get
replacement supplies such as activated carbon or parts for maintenance.
---------------------------------------------------------------------------

\68\ In promulgating the temporary use provisions in the OSWI
rules, the EPA recognized that there may be instances where it is
not technically feasible to operate a control device through the
entire duration of a disaster recovery period. (70 FR 74880; Dec.
16, 2005). Likewise, in this rule, the EPA is requiring that
existing controls continue to operate during the temporary use
period if technically feasible, thereby acknowledging potential
operational issues during such period but minimizing emissions where
there are not such issues.
---------------------------------------------------------------------------

We believe that during the disaster recovery period, CAA section
129 CISWI standards and associated requirements are not appropriate for
incinerators at commercial and industrial facilities that are burning
only non-hazardous debris and only long enough to complete the recovery
tasks; during the disaster recovery period, these incinerators are not
used as regular commercial and industrial waste disposal devices, which
Congress intended the CAA section 129 standards to regulate. Also, as
the EPA previously explained, ``in emergency situations, quick removal
of debris is of utmost importance to maintain public health and safety,
and temporary use incinerators may be best suited to dispose of
debris.'' \69\ Quick removal without complying with CAA Section 129
standards allows for the more expedited incineration of dried debris,
which reduces the near-term likelihood of catastrophic wildfires
occurring.\70\ If units elect to comply with the CISWI standards, they
may lose valuable time and bandwidth to incinerate debris as quickly as
possible. The EPA, therefore, elected to exclude incinerators from CAA
section 129 standards when they are used on a short-term basis to burn
debris during disaster recovery, noting that such ``regulation would
hinder the recovery effort and this impact would outweigh the benefits
from regulation of the units.'' \71\ The EPA found that ``this
proactive approach, which addresses the terms for use of a temporary-
use incinerator during declared emergencies or disasters, is better
than an approach

[[Page 13556]]

that requires the EPA and others to react during or immediately after
such an emergency or disaster strikes. This provision allows CISWI
operators in a disaster region to quickly shift from existing
operations to combusting only non-hazardous disaster debris, without
the impediment of complying with the CISWI standards during temporary
use. We also point out that States and the Federal government have
specific procedures that are followed in declaring an area a State of
Emergency or a major disaster area. Their procedures involve extensive
involvement by local, State, and Federal officials to conduct a
preliminary damage assessment, develop debris removal plans, and
coordinate and manage disaster assistance activities.''
---------------------------------------------------------------------------

\69\ 70 FR 74879, (Dec. 16, 2005).
\70\ U.S. EPA. No Action Assurance for the Use of Air Curtain
Incinerators to Manage Debris Caused By Hurricane Helene in North
Carolina (2024), <a href="https://www.deq.nc.gov/media/46792/download?attachment">https://www.deq.nc.gov/media/46792/download?attachment</a>.
\71\ 70 FR 74879, (Dec. 16, 2005).
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B. Temporary Use Period and Notifications

As in the OSWI regulations, we are not proposing to require any
notification for temporary use of CISWI units for disaster recovery
that lasts eight weeks or less (beginning on the date the unit starts
operation in response to a disaster or emergency). This ability to
start temporary use without notification during the first eight weeks
would ease the burden during or immediately after a disaster or
emergency. If the CISWI unit were used for longer than eight weeks, the
owner or operator would be required to notify the Administrator in
writing and request permission to continue to operate. Submitting such
notification would permit temporary use for an additional eight weeks,
which is a total of 16 weeks from the date the unit started operation.
The notification would have to be submitted in writing by the date
eight weeks after the temporary use incinerator starts operation and
would include the following information: the date the incinerator
started operation within the boundaries of the current emergency or
disaster declaration area; identification of the disaster or emergency
for which the incinerator is being used; a description of the types of
materials being burned in the incinerator; a brief description of the
size and design of the unit, including any existing control devices;
the reasons the incinerator must be operated for more than eight weeks;
the amount of time for which the owner or operator requests permission
to operate including the date the unit is expected to cease operation;
and, if applicable, a brief description of why the control devices are
infeasible to operate due to the disaster. If the request is for longer
than 16 weeks, the owner or operator would have to cease operation of
the unit or comply with applicable CISWI regulatory requirements at the
end of 16 weeks, unless the Administrator approves in writing a request
to continue operation. 16 weeks will be the maximum length of time a
temporary-use incinerator can operate in a given area declared a State
of Emergency or major disaster without specific permission to continue
operation from the Administrator. The approval of the request to
continue operating must establish a site-specific date to cease
operation. Similar to the OSWI exclusion, EPA is proposing this
approach, rather than a uniform maximum amount of time, because a case-
by-case approval process allows EPA and States to set the appropriate
time limits for the specific situation.
If finalized, the proposed temporary use provisions would directly
impact incinerators subject to the CISWI NSPS (40 CFR part 60, subpart
CCCC) and Federal plan (40 CFR part 62, subpart IIIa) but not those
subject to state plans implementing CISWI EG (40 CFR part 60, subpart
DDDD). States could then amend their State plans for existing CISWI
units to incorporate this temporary use provision.

X. Summary of Cost, Environmental, and Economic Impacts for CISWI
Temporary Use Incinerators in Disaster Recovery

We are proposing the temporary use of CISWI units during a disaster
or emergency, for the purposes of combusting related debris. Facilities
with CISWI units that use the disaster recovery temporary use
provisions would not be subject to additional control requirements;
they would not need to meet the existing CAA section 129 requirements
during this temporary use period. Therefore, we anticipate there would
not be any additional capital costs for compliance with this proposal
if finalized, only annual notification costs. As cleanup responses are
necessary during and following a disaster or emergency, we anticipate
that this action would have minimal adverse environmental impacts, as
the benefits of using CISWI units will outweigh the alternatives of
open burning and/or increased risk of wildfires that would degrade air
quality.\72\ As we are unable to quantify the number of units that
would be affected by this rulemaking, we are unable to quantify the
cost savings from this action at this time.
---------------------------------------------------------------------------

\72\ U.S. EPA, No Action Assurance for the Use of Air Curtain
Incinerators to Manage Debris Caused by Hurricane Helene in North
Carolina (2024). <a href="https://www.deq.nc.gov/media/46792/download?attachment">https://www.deq.nc.gov/media/46792/download?attachment</a>.
---------------------------------------------------------------------------

XI. Request for Comment for CISWI Temporary Use Incinerators in
Disaster Recovery

The EPA solicits comment on all aspects of this proposed action
described above. Comments can be submitted to the CISWI Docket ID No.
EPA-HQ-OAR-2003-0119.
In addition to general comments on this proposed action, we are
soliciting comments on the following topics. A comment reference
indicator for each specific topic is provided (e.g., Emergency-1,
Emergency-2, etc.).
<bullet> Incidents of insufficient numbers of incinerators for
emergency/disaster debris cleanup and the impacts on the affected
communities. (Emergency-1).
<bullet> Information on the difficulty with complying with CISWI
regulations during emergency/disaster debris cleanup. (Emergency-2).
<bullet> Information on State and local efforts in minimizing
health impact during emergency/disaster debris cleanup. (Emergency-3).

XII. Statutory and Executive Order Reviews

Additional information about these statutes and Executive Orders
can be found at <a href="https://www.epa.gov/laws-regulations/laws-and-executive-orders">https://www.epa.gov/laws-regulations/laws-and-executive-orders</a>.

A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 13563: Improving Regulation and Regulatory Review

The proposed actions to consolidate the regulations for ACI burning
only certain fuels and to allow for temporary use of CISWI units during
disasters or emergencies are not considered significant regulatory
actions as defined in Executive Order 12866. This proposal was
therefore not submitted to the Office of Management and Budget (OMB)
for review.

B. Executive Order 14192: Unleashing Prosperity Through Deregulation

This action proposing to consolidate regulations for ACI that only
burn wood wastes, yard wastes, clean lumber, or any mixture of those
materials is considered an Executive Order 14192 deregulatory action
because it would provide burden reduction by simplifying compliance and
some permitting requirements. This action to allow for temporary use of
CISWI units is considered an Executive Order 14192 deregulatory action
because it would reduce burdens for CISWI units during emergency and
disaster recovery with the temporary use provisions.

[[Page 13557]]

C. Paperwork Reduction Act (PRA)

The information collection activities in this action have been
submitted for approval to OMB under the PRA as discussed for each of
the relevant subpart discussed in sections XII.C.1, XII.C.2, and
XII.C.3.
1. ICR for Consolidated Air Curtain Incinerators: 40 CFR Part 60,
Subpart Ca
The Information Collection Request (ICR) document prepared by the
EPA has been assigned the EPA ICR number 7813.01. You can find a copy
of the ICR in Docket ID No. EPA-HQ-OAR-2025-0068, and it is briefly
summarized here.
The proposed rulemaking requires initial notifications and opacity
tests by the owners and operators of the affected facilities. Owners
and operators would also be required to maintain records of and submit
the results of opacity tests. These notifications, reports, and records
are essential in determining compliance and are required of all
affected facilities subject to the subpart. The EPA notes that most of
the burden associated with this ICR is burden being transferred from
existing ICRs for the subparts that currently regulate ACI that only
burn wood wastes, yard wastes, and clean lumber. The only new burden
for this ICR is associated with the initial notification of
applicability for existing units.
Respondents/affected entities: New or existing air curtain
incinerators that only burn wood wastes, yard wastes, and clean lumber.
Respondent's obligation to respond: Mandatory (40 CFR part 60,
subpart Ca).
Estimated number of respondents: 52.
Frequency of response: Once for startup/applicability notification,
annually for opacity test, as needed for disaster recovery for the
clean ACI.
Total estimated burden: 1,570 hours (per year), of which the EPA
estimates approximately 640 burden hours are currently associated with
the CISWI rules and 807 burden hours are currently associated with the
OSWI rules. Burden is defined at 5 CFR 1320.3(b).
Total estimated cost: $537,000, of which the EPA estimates that
approximately $230,000 is currently associated with the CISWI rules and
$290,000 is currently associated with the OSWI rules. The annualized
capital operation & maintenance costs are $156,000.
2. ICR for CISWI Temporary Use Incinerators NSPS: 40 CFR Part 60,
subpart CCCC
The information collection request (ICR) documents that the EPA
prepared have been assigned EPA ICR number 1926.10. You can find a copy
of the ICR in Docket ID No. EPA-HQ-OAR-2003-0119, and it is briefly
summarized here. The information collection requirements are not
enforceable until OMB approves them.
This action proposes to amend the current requirements in 40 CFR
part 60, subpart CCCC to allow owners and operators to temporarily
combust debris associated with disaster recovery. As part of these
proposed requirements, owners and operators would submit a notification
to the Administrator whenever an incinerator is used to combust this
type of debris for more than eight weeks. There would be no other
changes to the notification, recordkeeping, and reporting required in
these subparts. These notifications, reports, and records are essential
in determining compliance with the applicable subpart.
Respondents/affected entities: Owners and operators of new CISWI
units.
Respondent's obligation to respond: Mandatory if temporary use
exceeds eight weeks (40 CFR part 60, subpart CCCC).
Estimated number of respondents: 16, of which the EPA estimates
that approximately 1.6 will be subject to this proposed notification
requirement annually.
Frequency of response: As needed for disaster recovery.
Total estimated burden: 2,230 hours per year for 40 CFR part 60,
subpart CCCC, of which the EPA estimates approximately 3.7 hours are
associated with this notification annually. Burden is defined at 5 CFR
1320.3(b).
Total estimated cost: $1,530,000 (per year) for 40 CFR part 60,
subpart CCCC, of which the EPA estimates that approximately $529 is
associated with this notification annually.
3. ICR for CISWI Temporary Use Incinerators EG: 40 CFR Part 60, Subpart
DDDD and 40 CFR Part 62, Subpart IIIa
This action proposes to amend the current requirements in 40 CFR
part 60, subpart DDDD and 40 CFR part 62, subpart IIIa to allow owners
and operators to temporarily combust debris associated with disaster
recovery. As part of these proposed requirements, owners and operators
would submit a notification to the Administrator whenever an
incinerator is used to combust this type of debris for more than eight
weeks. There would be no other changes to the notification,
recordkeeping, and reporting required in these subparts. These
notifications, reports, and records are essential in determining
compliance with the applicable subpart.
Respondents/affected entities: Owners and operators of existing
CISWI units.
Respondent's obligation to respond: Mandatory if temporary use
exceeds eight weeks (40 CFR part 60, subpart DDDD, and 40 CFR part 62,
subpart IIIa).
Estimated number of respondents: 76 for 40 CFR part 60, subpart
DDDD and 40 CFR part 62, subpart IIIa, of which the EPA estimates that
approximately 2.7 existing units will be subject to this proposed
notification requirement annually.
Frequency of response: As needed for disaster recovery.
Total estimated burden: 8,510 hours per year for 40 CFR part 60,
subpart DDDD and 40 CFR part 62, subpart IIIa, of which the EPA
estimates approximately 6.2 burden hours are associated with this
notification annually. Burden is defined at 5 CFR 1320.3(b).
Total estimated cost: $13,500,000 (per year) for 40 CFR part 60,
subpart DDDD and 40 CFR part 62, subpart IIIa, of which the EPA
estimates that approximately $893 is associated with this notification
annually.
An agency may not conduct or sponsor, and a person is not required
to respond to a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations in 40 CFR part 51 are listed in 40 CFR part 9. Submit your
comments on the agency's need for this information, the accuracy of the
provided burden estimates, and any suggested methods for minimizing
respondent burden to the EPA using the docket identified at the
beginning of this rule. The EPA will respond to any ICR related
comments in the final rule. You may also send your ICR-related comments
to OMB's Office of Information and Regulatory using the interface at
<a href="http://www.reginfo.gov/public/doPRAMain">www.reginfo.gov/public/doPRAMain</a>. Find this particular information
collection by selecting ``Currently under Review-Open for Public
Comments'' or by using the search function. OMB must receive comments
no later than April 20, 2026.

D. Regulatory Flexibility Act (RFA)

I certify that these proposed actions will not have a significant
economic impact on a substantial number of small entities under the
RFA. In making this determination, EPA concludes that the impact of
concern for this rulemaking is any significant adverse economic impact
on small entities, and that the agency is certifying that this
rulemaking will not have a significant economic

[[Page 13558]]

impact on a substantial number of small entities because the rule
relieves regulatory burden on the small entities subject to the rule.
This Consolidated ACI proposed action will impose monitoring,
recordkeeping and reporting requirements that currently exist in the
respective rules for OSWI, CISWI, LMWC and SMWC units. We only
anticipate the additional costs of the initial notification
requirements. The EPA has a provided a memo in the docket for this
action titled, ``Economic Impact and Small Business Analysis for the
Consolidated Air Curtain Incinerators (ACI) and Temporary Use of
Commercial Industrial Solid Waste Incinerators (CISWI) Proposed Rule.''
For the CISWI Temporary Use Incinerator Actions, there are no
additional control requirements and thereby no additional compliance
costs. Therefore, we conclude that this action will relieve regulatory
burden for all directly regulated small entities.

E. Unfunded Mandates Reform Act (UMRA)

These proposed actions do not contain unfunded mandates of $100
million or more as described in the 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

These proposed actions do not have federalism implications. The
actions 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

These proposed do not have Tribal implications. It will neither
impose substantial direct compliance costs on federally recognized
Tribal governments, nor preempt Tribal law.

H. Executive Order 13045: Protection of Children From Environmental
Health Risks 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.
The proposed actions are not subject to Executive Order 13045
because it does not concern an environmental health risk or safety
risk. Since this action does not concern human health, EPA's Policy on
Children's Health also does not apply.

I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use

These proposed are not ``significant energy actions'' because they
are not likely to have a significant adverse effect on the supply,
distribution, or use of energy. Further, we have concluded that this
action is not likely to have adverse energy effects because it does not
involve energy supply, distribution, or use of energy.

J. National Technology Transfer and Advancement Act (NTTAA) and 1 CFR
Part 51

This notice of proposed rulemaking involves technical standards for
ACI that only burn wood wastes, yard wastes, and clean lumber.
Therefore, the EPA conducted searches through the Enhanced National
Standards System Network Database managed by the American National
Standards Institute (ANSI) to determine if there are voluntary
consensus standards (VCS) that are relevant to this action. We
conducted searches for EPA Method 9 of 40 CFR part 60, appendix A.
During the search, if the title or abstract (if provided) of the VCS
described technical sampling and analytical procedures that are similar
to the EPA's reference method, the EPA considered it as a potential
equivalent method. All potential standards were reviewed to determine
the practicality of the VCS for these rules. This review requires
significant method validation data which meet the requirements of EPA
Method 301 for accepting alternative methods or scientific, engineering
and policy equivalence to procedures in the EPA reference methods. The
EPA may reconsider determinations of impracticality when additional
information is available for particular VCS. ASTM D7520-16, Standard
Test Method for Determining the Opacity of a Plume in the Outdoor
Ambient Atmosphere, approved April 1, 2016, describes how digital
imagery and associated hardware and software is used to determine the
opacity of a plume. The EPA will allow the voluntary consensus standard
ASTM D7520-16, as an acceptable alternative to EPA Method 9 with the
following caveats:
1. During the digital camera opacity technique (DCOT) certification
procedure outlined in section 9.2 of ASTM D7520-16, you (the operator
of the regulated unit) or the DCOT vendor must present the plumes in
front of various backgrounds of color and contrast representing
conditions anticipated during field use such as blue sky, trees, and
mixed backgrounds (clouds and a sparse tree stand).
2. You must also have standard operating procedures in place
including daily or other frequency quality checks to ensure the
equipment is within manufacturing specifications as outlined in Section
8.1 of ASTM D7520-16.
3. You must follow the recordkeeping procedures outlined in section
63.10(b)(1) for the DCOT certification, compliance report, data sheets,
and all raw unaltered JPEGs used for opacity and certification
determination.
4. You or the DCOT vendor must have a minimum of four (4)
independent technology users apply the software to determine the
visible opacity of the 300 certification plumes. For each set of 25
plumes, the user may not exceed 15 percent opacity of anyone reading
and the average error must not exceed 7.5 percent opacity.5. Use of
this approved alternative does not provide or imply a certification or
validation of any vendor's hardware or software. The onus to maintain
and verify the certification and training of the DCOT camera, software
and operator in accordance with ASTM D7520-16 and these requirements is
on the facility, DCOT operator, and DCOT vendor. This method is
available at ASTM International, 1850 M Street NW, Suite 1030,
Washington, DC 20036. See <a href="http://www.astm.org">www.astm.org</a>. The standard is available to
everyone at a cost determined by ASTM. The cost of obtaining this
method is not a significant financial burden, making the method
reasonably available. Additional information for the VCS search and
determinations can be found in the memorandum, Voluntary Consensus
Standard Results for Consolidation of standards for air curtain
incinerators that only burn wood wastes, yard wastes, and clean lumber,
which is available in the docket for this action (Docket ID No. EPA-HQ-
OAR-2025-0068).
Under 40 CFR 60.8(b) and 60.13(i) of subpart A of the General
Provisions, a source may apply to the EPA to use alternative test
methods or alternative monitoring requirements in place of any required
testing methods, performance

[[Page 13559]]

specifications or procedures in the final rule or any amendments.

Lee Zeldin
Administrator.
[FR Doc. 2026-05491 Filed 3-19-26; 8:45 am]
BILLING CODE 6560-50-P

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