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Proposed Rule2026-22082

Additional Reconsideration Standards of Performance for New, Reconstructed, and Modified Sources and Emissions Guidelines for Existing Sources: Oil and Natural Gas Sector Climate Review

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Published

October 29, 2026

Issuing agencies

Environmental Protection Agency

Abstract

The U.S. Environmental Protection Agency (EPA) is proposing amendments to the New Source Performance Standards and Emission Guidelines for the Crude Oil and Natural Gas Source Category to address additional concerns raised with prior regulatory amendments finalized in March 2024. Specifically, the EPA is proposing changes in response to certain petitions for reconsideration of the March 2024 amendments, changes based on policy decisions and supporting legal interpretations, and changes that correct and clarify the regulatory text of the new source performance standards and emission guidelines. First, the EPA proposes to rescind the Super Emitter Program. Second, the EPA proposes to subcategorize different types of well sites affected and designated facilities to address issues related to the requirements finalized in March 2024 for marginal well sites and conventional well sites. Third, the EPA proposes changes to address issues related to liquids unloading, process controllers, pumps, fugitive emissions, storage vessels, covers and closed vent systems, equipment leaks at gas plants, and associated gas. Fourth, the EPA proposes changes to certain requirements finalized in March 2024 related to control devices and to provide owners and operators the option to conduct optical gas imaging surveys according to Appendix K for gas processing facilities. Lastly, the EPA proposes changes to correct inadvertent errors and to clarify regulatory language.

Full Text

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[Federal Register Volume 91, Number 208 (Thursday, October 29, 2026)]
[Proposed Rules]
[Pages 68234-68361]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-22082]

[[Page 68233]]

Vol. 91

Thursday,

No. 208

October 29, 2026

Part II

Environmental Protection Agency

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40 CFR Part 60

Additional Reconsideration Standards of Performance for New,
Reconstructed, and Modified Sources and Emissions Guidelines for
Existing Sources: Oil and Natural Gas Sector Climate Review; Proposed
Rule

Federal Register / Vol. 91, No. 208 / Thursday, October 29, 2026 /
Proposed Rules

[[Page 68234]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 60

[EPA-HQ-OAR-2025-0163; FRL-12726-01-OAR]
RIN 2060-AW73

Additional Reconsideration Standards of Performance for New,
Reconstructed, and Modified Sources and Emissions Guidelines for
Existing Sources: Oil and Natural Gas Sector Climate Review

AGENCY: Environmental Protection Agency.

ACTION: Proposed rule.

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SUMMARY: The U.S. Environmental Protection Agency (EPA) is proposing
amendments to the New Source Performance Standards and Emission
Guidelines for the Crude Oil and Natural Gas Source Category to address
additional concerns raised with prior regulatory amendments finalized
in March 2024. Specifically, the EPA is proposing changes in response
to certain petitions for reconsideration of the March 2024 amendments,
changes based on policy decisions and supporting legal interpretations,
and changes that correct and clarify the regulatory text of the new
source performance standards and emission guidelines. First, the EPA
proposes to rescind the Super Emitter Program. Second, the EPA proposes
to subcategorize different types of well sites affected and designated
facilities to address issues related to the requirements finalized in
March 2024 for marginal well sites and conventional well sites. Third,
the EPA proposes changes to address issues related to liquids
unloading, process controllers, pumps, fugitive emissions, storage
vessels, covers and closed vent systems, equipment leaks at gas plants,
and associated gas. Fourth, the EPA proposes changes to certain
requirements finalized in March 2024 related to control devices and to
provide owners and operators the option to conduct optical gas imaging
surveys according to Appendix K for gas processing facilities. Lastly,
the EPA proposes changes to correct inadvertent errors and to clarify
regulatory language.

DATES: Comments must be received on or before December 16, 2026. The
EPA will announce further details at <a href="https://www.epa.gov/controlling-air-pollution-oil-and-natural-gas-operations">https://www.epa.gov/controlling-air-pollution-oil-and-natural-gas-operations</a>. Under the Paperwork
Reduction Act, comments on the information collection provisions are
best assured of consideration if the Office of Management and Budget
receives a copy of your comments on or before November 30, 2026.
Public Hearing. The EPA will hold a virtual public hearing on
November 13, 2026. Please refer to the SUPPLEMENTARY INFORMATION for
information on registering for the public hearing.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OAR-2025-0163, by any of the following methods:
<bullet> Federal eRulemaking Portal: <a href="https://www.regulations.gov">https://www.regulations.gov</a>
(our preferred method). Follow the online instructions for submitting
comments.
<bullet> Email: <a href="/cdn-cgi/l/email-protection#f796da969993da85da9398949c9283b7928796d9909881">[email&#160;protected]</a>. Include Docket ID No. EPA-
HQ-OAR-2025-0163 in the subject line of the message.
<bullet> Mail: U.S. Environmental Protection Agency, EPA Docket
Center, Docket ID No. EPA-HQ-OAR-2025-0163, 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, Washington, DC 20004.
The Docket Center's hours of operation are 8:30 a.m. to 4:30 p.m.
Eastern Time (ET), Monday through 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="https://www.regulations.gov">https://www.regulations.gov</a>, including any personal information
provided. For detailed instructions on sending written comments and
additional information on the rulemaking process, see the SUPPLEMENTARY
INFORMATION section of this preamble.

FOR FURTHER INFORMATION CONTACT: For information about this proposed
rule, contact Paz Aviles, Natural Resources Division, Office of Clean
Air Programs, U.S. Environmental Protection Agency, 1200 Pennsylvania
Avenue NW, Washington, DC 20460; telephone number: (202) 564-9822; and
email address: <a href="/cdn-cgi/l/email-protection#3352455a5f56401d435249735643521d545c45">[email&#160;protected]</a>. Additional questions may be directed
to the following email address: <a href="/cdn-cgi/l/email-protection#3c731a7b715948545d52596e4950597c594c5d125b534a">[email&#160;protected]</a>.

SUPPLEMENTARY INFORMATION:
Participation in virtual public hearing. The hearing will be held
via virtual platform November 16, 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/controlling-air-pollution-oil-and-natural-gas-operations">https://www.epa.gov/controlling-air-pollution-oil-and-natural-gas-operations</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/controlling-air-pollution-oil-and-natural-gas-operations">https://www.epa.gov/controlling-air-pollution-oil-and-natural-gas-operations</a> or contact the public hearing
team at (888) 372-8699 or by email at <a href="/cdn-cgi/l/email-protection#145a4650646176787d777c7175667d7a73547164753a737b62">[email&#160;protected]</a>. The
last day to pre-register to speak at the hearing will be November 10,
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/controlling-air-pollution-oil-and-natural-gas-operations">https://www.epa.gov/controlling-air-pollution-oil-and-natural-gas-operations</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
hearings 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 a copy of their oral testimony
as written comments electronically 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/controlling-air-pollution-oil-and-natural-gas-operations">https://www.epa.gov/controlling-air-pollution-oil-and-natural-gas-operations</a>. While the EPA expects the hearing to go
forward as set forth above, please monitor our website or contact the
public hearing team at (888) 372-8699 or by email at
<a href="/cdn-cgi/l/email-protection#aae4f8eedadfc8c6c3c9c2cfcbd8c3c4cdeacfdacb84cdc5dc">[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 special accommodation such as audio description,
please pre-register for the hearing with the public hearing team and
describe your needs by November 9, 2026. The EPA may not be able to
arrange accommodations without advance notice.
Docket. The EPA has established a docket for this rulemaking under
Docket ID No. EPA-HQ-OAR-2025-0163. All documents in the docket are
listed at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Although listed, some
information is not publicly available, e.g., Confidential Business

[[Page 68235]]

Information (CBI) or other information whose disclosure is restricted
by statute. The EPA does not place certain other material, such as
copyrighted material, on the internet; this material is publicly
available only as portable document format versions accessible only on
EPA computers in the docket office reading room. The public cannot
download certain databases and physical items from the docket but may
request these items by contacting the docket office at (202) 566-1744.
The docket office has 10 business days to respond to such requests.
With the exception of such material, publicly available docket
materials are available electronically at <a href="https://www.regulations.gov">https://www.regulations.gov</a>
or on EPA computers in the docket office reading room at the EPA Docket
Center, WJC West Building, Room Number 3334, 1301 Constitution Ave. NW,
Washington, DC. The Public Reading Room hours of operation are 8:30
a.m. to 4:30 p.m. ET, Monday through Friday. The telephone number for
the Public Reading Room is (202) 566-1744, and the telephone number for
the EPA Docket Center is (202) 566-1742. Pursuant to the Administrative
Procedure Act at 5 U.S.C. 553(b)(4), a plain language summary of this
rule is available on the docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a>.
Written Comments. Direct your comments to Docket ID No. EPA-HQ-OAR-
2025-0163. The EPA's policy is that the public docket will contain all
comments received without change and made available online at <a href="https://www.regulations.gov">https://www.regulations.gov</a>, including any personal information provided,
unless the comment includes information claimed to be CBI or other
information for which a statute restricts disclosure. Do not submit
electronically to <a href="https://www.regulations.gov">https://www.regulations.gov</a> any information that you
consider to be CBI or other information for which a statute restricts
disclosure. You should submit this type of information as described in
the Submitting CBI section of this preamble.
The EPA may publish any comment received to its public docket. A
written comment must accompany multimedia submissions (audio, video,
etc.). The EPA considers the written comment to be the official
comment, and it should include discussion of all points you wish to
make. The EPA will generally not consider comments or comment contents
located outside of the primary submission (i.e., on the Web, cloud, or
other file sharing system). For additional submission methods, the full
EPA public comment policy, information about CBI or multimedia
submissions, and general guidance on making effective comments, please
visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.
The <a href="https://www.regulations.gov">https://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="https://www.regulations.gov">https://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 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="https://www.epa.gov/dockets">https://www.epa.gov/dockets</a>.
The EPA solicits comment on numerous aspects of this proposed rule.
The EPA has indexed each comment solicitation with an identifier (e.g.,
``C-1, C-2, . . .'') to provide a consistent framework for effective
and efficient provision of comments. Accordingly, the EPA asks that
commenters include the corresponding identifier when providing comments
relevant to that comment solicitation. The EPA asks that commenters
include the identifier in either a heading or in the text of each
comment (e.g., ``In response to C-1, . . .'') to make clear which
comment solicitation you are addressing. The EPA emphasizes that the
EPA is not limiting comment to these identified areas and encourage you
to provide any other comments relevant to this proposal.
Submitting CBI. Do not submit information containing CBI to the EPA
through <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Clearly mark the part or all the
information that you claim to be CBI. For CBI information on any
digital storage media that you mail to the EPA, note the docket ID,
mark the outside of the digital storage media as CBI, and 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 Instructions above. 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 part 2.
Our preferred method to receive CBI is for it to be transmitted
electronically using email attachments, File Transfer Protocol, 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 at the email address <a href="/cdn-cgi/l/email-protection#244b47455447464d644154450a434b52">[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 contact the person
listed in the FOR FURTHER INFORMATION CONTACT section to receive
instructions.
Preamble acronyms and abbreviations. Throughout this document the
use of ``we,'' ``us,'' or ``our'' is intended to refer to the EPA. The
Agency uses multiple acronyms and terms in this preamble. While this
list may not be exhaustive, to ease the reading of this preamble and
for reference purposes, the EPA defines the following terms and
acronyms here:

AMEL alternative means of emission limitation
API American Petroleum Institute
ASTM ASTM International
AVO audible, visual, and olfactory
BCD backup control devices
BMPs best management practices
boe barrels of oil equivalents
BSER best system of emission reduction
[deg]C degrees Celsius
CAA Clean Air Act
CBI Confidential Business Information
CDX Central Data Exchange
CEDRI Compliance and Emissions Data Reporting
CFR Code of Federal Regulations
CVS closed vent systems
DOE Department of Energy
EAV equivalent annualized values
ECD enclosed combustion device
EG emission guidelines
EPA Environmental Protection Agency
[deg]F degrees Fahrenheit
FR Federal Register
g/hr grams per hour
GHG greenhouse gas
GOR gas-to-oil ratio
H<INF>2</INF>S hydrogen sulfide
ICR information collection request
IFR interim final rule

[[Page 68236]]

kg/hr kilograms per hour
low-E low emission
LDAR leak detection and repair
LPE legally and practicably enforceable
Mcfd thousand cubic feet per day
MOGA Michigan Oil and Gas Association
MPT Manufacturers' Performance Test
NAAQS National Ambient Air Quality Standards
NAICS North American Industry Classification System
NDE no detectable emissions
NESHAP National Emission Standards for Hazardous Air Pollutants
NIE no identifiable emissions
NHV net heating value
NSPS new source performance standards
NTTAA National Technology Transfer and Advancement Act
OCAP Office of Clean Air Programs
OGI optical gas imaging
OIRA Office of Information and Regulatory Affairs
OMB Office of Management and Budget
psig Pounds per square inch gauge
ppmv parts per million by volume
PRA Paperwork Reduction Act
PTE potential to emit
PV present value
RFA Regulatory Flexibility Act
RIA regulatory impact analysis
scfh standard cubic feet per hour
SO<INF>2</INF> sulfur dioxide
TCD temporary control device
tpy tons per year
TIP Tribal Implementation Plan
TSD technical support document
UMRA Unfunded Mandates Reform Act
U.S. United States
VOC volatile organic compound(s)
VRU vapor recovery unit

Table of Contents

I. Executive Summary
II. General Information
A. Applicability of This Regulatory Action
B. Availability of This Document and Other Related Information
C. Purpose of This Regulatory Action
D. Statutory Background and Authority
E. Regulatory History and Background of NSPS and EG for the
Crude Oil and Natural Gas Source Category
III. Summary and Rationale of Proposed Amendments to NSPS OOOOb and
EG OOOOc
A. Super Emitter Program
B. Liquids Unloading
C. Process Controllers
D. Pumps
E. Fugitive Emissions
F. Storage Vessels
G. Covers and Closed Vent Systems
H. Control Devices
I. Equipment Leaks at Gas Plants
J. Associated Gas From Wells Producing Primarily Oil
K. Well Site Subcategorization
IV. Technical Corrections and Clarifications
A. NSPS Subparts OOOO and OOOOa Technical Corrections and
Clarifications
B. NSPS Subpart OOOOb Technical Corrections and Clarifications
C. EG Subpart OOOOc Technical Corrections and Clarifications
V. Appendix K
A. Summary of Provisions Promulgated in March 2024 Final Rule
B. Petitioners' Concerns and Supporting Information, Summary of
Proposed Changes, and Basis for Proposed Changes
VI. Summary of Cost, Environmental, and Economic Impacts
VII. Request for Comments
VIII. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and 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 Code of Federal Regulations (CFR) Part 51

I. Executive Summary

On March 8, 2024, the EPA published a final rule amending and
expanding requirements for the Crude Oil and Natural Gas source
category under Clean Air Act (CAA) sections 111(b) and (d) (``March
2024 Final Rule'').\1\ The EPA finalized new source performance
standards (NSPS) for greenhouse gas (GHG) and volatile organic compound
(VOC) emissions from new, modified, and reconstructed sources in this
source category, codified in 40 Code of Federal Regulations (CFR) part
60, subpart OOOOb (NSPS OOOOb). The EPA also finalized emission
guidelines (EG) for GHG emissions from existing sources in this source
category, codified in 40 CFR part 60, subpart OOOOc (EG OOOOc). The
NSPS OOOOb applies to thousands of new sources, whose construction,
reconstruction, or modification began after December 6, 2022, and the
EG OOOOc covers hundreds of thousands of existing sources in the Crude
Oil and Natural Gas source category. Crude oil production applicability
includes the well and extends to the point of custody transfer to the
crude oil transmission pipeline or any other forms of transportation.
Natural gas production applicability includes production, processing,
transmission, and storage, which includes the well and extends to, but
does not include, the local distribution company custody transfer
station.
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\1\ 89 FR 16820 (March 8, 2024).
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The March 2024 Final Rule broke new ground in multiple respects. In
EG OOOOc, the EPA required States to regulate GHG emissions from
hundreds of thousands of existing sources in the Crude Oil and Natural
Gas source category for the first time. This novel and massive task is
presenting additional and, at times, unforeseen coordination and
compliance difficulties. For several aspects of NSPS OOOOb and EG
OOOOc, the EPA promulgated ambitious ``zero-emission requirements''
predicated on very different best system of emissions reduction (BSER)
determinations. With respect to associated gas produced during oil
extraction, for example, the EPA predicated its zero-emission standard
for new sources on a BSER of routing gas to sales lines based on the
assumption that sources would be located in an area where such
infrastructure--generally owned and operated by third parties--is, or
would be, established at sufficient scale. Recognizing that not all
existing sources fit within that assumption, the Agency built
subcategories into the BSER analysis and resulting presumptive
standards that allow continued flaring under certain circumstances. For
new sources, the Agency concluded that it was appropriate to require
routing to a sales line based, among other things, on a cost-
effectiveness analysis that assumed new sources would be located within
50 miles of existing infrastructure. This approach broadened the BSER
analysis from source-centered compliance to one that very heavily
relied on industry-wide participants unregulated by NSPS OOOOb and EG
OOOOc, which raised novel legal and policy questions that the Agency
did not fully grapple with at the time of promulgation. The resulting
new source standard in the March 2024 Final Rule, as discussed herein,
risks limiting the development of new oil and gas extraction areas
where potential sources must hold back until or unless necessary
infrastructure develops, thereby coming into tension with the economics
of the industry, national security and energy priorities, and CAA
section 111's instruction to develop new source standards that can be
achieved across the Nation.
After publication of the March 2024 Final Rule, the EPA received
multiple petitions for reconsideration.\2\ On May 6, 2024, the EPA
notified certain petitioners and the public that the Agency granted
reconsideration on two discrete aspects of the March 2024 Final

[[Page 68237]]

Rule: the temporary flaring provisions for associated gas in certain
situations; and the vent gas net heating value (NHV) continuous
monitoring requirements and alternative performance test (sampling
demonstration) option for flares and enclosed combustion
devices.3 4
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\2\ See Docket No. EPA-HQ-OAR-2025-0163 for petitions for
reconsideration received.
\3\ See Docket No. EPA-HQ-OAR-2025-0163 for May 6, 2024, letter
granting reconsideration.
\4\ In the May 6, 2024, letter to petitioners, the EPA also took
the opportunity to clarify the applicable timeframe for performance
testing with respect to NHV sampling.
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On January 15, 2025, the EPA proposed amendments to the NSPS and EG
for Existing Sources for the Crude Oil and Natural Gas Source Category
in response to these petitions for reconsideration (``January 2025
Reconsideration Proposal'').\5\ Specifically, the EPA proposed discrete
technical changes to two different aspects of the March 2024 Final Rule
(i.e., technical changes to the temporary flaring provisions for
associated gas in certain situations; technical changes to the vent gas
NHV continuous monitoring requirements and alternative performance test
(sampling demonstration) option for flares and enclosed combustion
devices).
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\5\ 90 FR 3734 (January 15, 2025).
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On April 9, 2026, the EPA finalized amendments to the March 2024
Final Rule resulting from our reconsideration of these two discrete
issues (``April 2026 Reconsideration Final Rule'').\6\ The EPA is not
reopening NHV issues from the April 2026 Reconsideration Final Rule in
this new rule. This package is proposing changes to associated gas and
can be found in section III.J. of this preamble. The proposed changes
to associated gas will address broader issues than those raised in the
April 2026 Reconsideration Final Rule, including proposing to remove
the provisions related to temporary flaring.
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\6\ 91 FR 18056 (April 9, 2026).
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On January 20, 2025, the President issued Executive Orders 14154
(Unleashing American Energy) and 14156 (Declaring a National Energy
Emergency).7 8 Then, on January 31, 2025, the President
issued Executive Order 14192 (Unleashing Prosperity through
Deregulation).\9\ On March 12, 2025, the EPA announced plans for
deregulatory actions to, among other things, unleash American
energy.\10\ On that same day, the Agency announced plans to reconsider
the regulations in the March 2024 Final Rule ``to ensure they do not
prevent America from unleashing energy dominance.'' \11\
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\7\ 90 FR 8353 (January 29, 2025).
\8\ 90 FR 8433 (January 29, 2025).
\9\ 90 FR 9065 (February 6, 2025).
\10\ EPA Press Release: EPA Launches Biggest Deregulatory Action
in U.S. History. <a href="https://www.epa.gov/newsreleases/epa-launches-biggest-deregulatory-action-us-history">https://www.epa.gov/newsreleases/epa-launches-biggest-deregulatory-action-us-history</a>. March 12, 2025.
\11\ EPA Press Release: Trump EPA Announces OOOO b/c
Reconsideration of Biden-Harris Rules Strangling American Energy
Producers. <a href="https://www.epa.gov/newsreleases/trump-epa-announces-oooo-bc-reconsideration-biden-harris-rules-strangling-american">https://www.epa.gov/newsreleases/trump-epa-announces-oooo-bc-reconsideration-biden-harris-rules-strangling-american</a>.
March 12, 2025.
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On July 31, 2025, the EPA promulgated an interim final rule (``July
2025 IFR'') which extended deadlines for certain provisions in the NSPS
OOOOb related to control devices, equipment leaks, storage vessels,
process controllers, and covers and closed vent systems (CVS) to
address legitimate concerns, raised by stakeholders, that certain
regulatory provisions were not currently workable or contained
problematic regulatory language that frustrates compliance.\12\ Within
that IFR, the EPA also extended the date for future implementation of
the Super Emitter Program and extended the State plan submittal
deadline in EG OOOOc. The EPA solicited public comment on the
extensions included in the July 2025 IFR. The EPA considered the
comments received, and then, in December 2025, the EPA promulgated a
final rule which responded to the comments and reaffirmed the
conclusions and the regulatory amendments made in the IFR (``December
2025 Final Rule'').\13\ In response to comments received on the July
2025 IFR, the December 2025 Final Rule provided an additional 180-day
extension (from the final rule's effective date) (until June 1, 2026)
to the compliance dates related to NHV monitoring of flares and
enclosed combustion devices (ECDs) found in 40 CFR 60.5417b(d)(8)(i)
through (iv) and (vi), as well as 360 days from the effective date of
the December 2025 Final Rule (November 30, 2026) for owners and
operators to submit initial annual reports pursuant to 40 CFR
60.5420(b).\14\
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\12\ 90 FR 35966 (July 31, 2025).
\13\ 90 FR 55671 (December 3, 2025).
\14\ See 90 FR 35970-35972 (July 31, 2025), and 90 FR 55675-
55676 (December 3, 2025) for discussion of the rationale for NHV
monitoring extension.
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This proposal reflects the EPA's reconsideration of additional
aspects of the March 2024 Final Rule, including some of the Agency's
prior BSER determinations and the legal and policy positions taken in
finalizing those determinations. Upon further review, and in light of
information considered since promulgation, the EPA no longer believes
that some of the ``zero-emission'' requirements in NSPS OOOOb and EG
OOOOc are predicated on acceptable assessments of emissions reductions,
cost effectiveness, and achievability. In some cases, the March 2024
Final Rule moved from requirements that control 95 percent of emissions
to standards stated as ``zero-emission'' requirements. However,
achievability limitations and compliance difficulties, including those
the EPA anticipated at the time by building in exemptions and those the
Agency did not foresee, suggest that the requirements' emission
reductions potential are more modest than previously anticipated. At
the same time, the Agency very likely underestimated costs because the
actual costs of compliance are likely higher than the EPA anticipated
in the March 2024 Final Rule. The resulting reconsideration--taking
into account more modest emissions reductions and more significant
costs--suggests that significant aspects of some BSER determinations
and resulting standards in the March 2024 Final Rule are inappropriate.
EPA solicits comment on further considerations relative to the March
2024 Final Rule, such as those petitioners have flagged.
In this action, the EPA proposes the following:
<bullet> Rescinding the Super Emitter Program in NSPS OOOO, OOOOa,
OOOOb, and EG OOOOc based on a change in policy direction, concerns
with the authority of the program, and a reassessment of the Program's
expected effectiveness in light of new information.
<bullet> Revising several aspects of NSPS OOOOb and EG OOOOc based
on petitions received on the March 2024 Final Rule. Specifically, the
EPA proposes changes to the March 2024 Final Rule requirements to
address certain petitioner concerns for liquids unloading, process
controllers, pumps, fugitive emissions, storage vessels, covers and
CVSs, and equipment leaks at gas plants.
<bullet> Revising the March 2024 Final Rule requirements related to
control devices, such as requirements for continuous burning pilot
flames, flame monitoring data deviations, control device alerts,
visible emissions test conditions for fugitive emissions, control
devices used on a temporary or backup basis, temporary process
controllers, and control device categories.
<bullet> Proposing changes related to requirements for controlling
emissions from associated gas from wells producing primarily oil. The
EPA is proposing that routing to a sales-line is not an appropriate
BSER for these emissions. The Agency is proposing that routing
associated gas to a control device or a flare that achieves 95%

[[Page 68238]]

reductions in emissions or greater should be BSER instead.
<bullet> Proposing to add a new subcategory for certain well sites
affected and designated facilities based on a variety of operational
conditions. This aspect of the proposal also includes revisions to
requirements that apply at certain well sites that address concerns
related to the appropriateness of the categorization and the burden
associated with complying with the March 2024 Final Rule requirements.
Specifically, in this action, the EPA is co-proposing two alternative
approaches to subcategorizing well sites:
[ssquf] An option based on marginal and non-marginal well sites
that would include reduced requirements for marginal wells. The EPA
also solicits comment on an alternative approach to a marginal well
site subcategory that would further subcategorize marginal wells based
on production levels.
[ssquf] An option based on conventional and non-conventional wells
that would include reduced requirements for conventional wells.
<bullet> Allowing for owners and operators to conduct optical gas
imaging (OGI) surveys according to Appendix K for NSPS OOOO, OOOOa, and
KKK at gas processing facilities.
<bullet> Making technical corrections and clarifications to NSPS
OOOO, OOOOa, OOOOb, and EG OOOOc.
The EPA solicits comments on its proposed regulatory changes.
Within this preamble, the EPA is also soliciting broader comment on
further issues relevant to the March 2024 Final Rule and resulting NSPS
OOOOb and EG OOOOc, including both the additional issues raised by
reconsideration petitioners for which the EPA is not proposing
regulatory changes at this time and any additional issues commenters
believe are relevant to the lawfulness, reasonableness, or
implementability of the 2024 Final Rule. (Question I.1)
The EPA is also clarifying in this preamble an inconsistency
identified in the amendatory instructions published as part of the
April 2026 Reconsideration Final Rule. The amendatory language appeared
to indicate a revision to 40 CFR60.5417b(i)(6),\15\ which had been
revised as part of an earlier action (an IFR promulgated on July 31,
2025). The regulatory text in the CFR correctly reflects that earlier
amendment. The inconsistency occurred only in the amendatory
instructions and did not affect the regulatory text. In this notice,
the EPA is not proposing any revisions to paragraph 40 CFR
60.5417b(i)(6)(v). The EPA is instead clarifying the source of the
discrepancy to ensure transparency in the rulemaking record and to
confirm that the existing regulatory text remains accurate and
unchanged.
---------------------------------------------------------------------------

\15\ 91 FR 18094 (April 9, 2026).
---------------------------------------------------------------------------

The EPA estimated present values (PV) and equivalent annualized
values (EAV) of the estimated increase in economic surplus of this
proposal and co-proposal in 2024 dollars over the 2027 to 2050 period,
discounted to 2025. Estimated increases in economic surplus include
reductions in compliance cost expenditures from industry, as well as
increased value to consumers from lower commodity prices and revenues
to industry from increased production. Surplus changes also account for
the forgone value of natural gas captured as a result of less stringent
compliance obligations. Changes beyond compliance cost savings are
represented by the Savings from Energy Market Impacts values. Table 1
presents the estimated additional economic surplus of this proposed
action in 2024 dollars for the baseline which includes the March 2024
Final Rule (i.e., the primary baseline analyzed in the regulatory
impact analysis (RIA)).
BILLING CODE 6560-50-P
[GRAPHIC] [TIFF OMITTED] TP29OC26.006

BILLING CODE 6560-50-C
See section VI of this preamble (Summary of Cost, Environmental,
and Economic Impacts) for additional information.

[[Page 68239]]

II. General Information

A. Applicability of This Regulatory Action

The source category that is the subject of this proposal is the
Crude Oil and Natural Gas Source Category regulated under CAA section
111, NSPS and EG. The 2022 North American Industry Classification
System (NAICS) code for the source category is summarized in table 2.
The NAICS codes serve as a guide for readers outlining the entities
that this proposed action is likely to affect, if finalized. The NSPS
codified in 40 CFR part 60, subpart OOOOb, are directly applicable to
affected facilities that begin construction, reconstruction, or
modification after December 6, 2022. As shown in table 2, Federal,
State, and local government entities would not be affected by the NSPS
action.
[GRAPHIC] [TIFF OMITTED] TP29OC26.007

This table is not intended to be exhaustive but rather provides a
guide for readers regarding entities likely to be affected by the NSPS
action with respect to new sources. Other types of entities not listed
in the table could also be affected by the NSPS action. To determine
whether your entity is affected by any of the NSPS action, you should
carefully examine the applicability criteria found in the final NSPS
rule. If you have questions regarding the applicability of the NSPS
rule to a particular entity, consult the person listed in the FOR
FURTHER INFORMATION CONTACT section, your State air pollution control
agency with delegated authority for NSPS, or your EPA Regional Office.
The issuance of the CAA section 111(d) EG in March 2024 did not
directly impose binding requirements on existing sources, but instead
established requirements applicable to states in developing their
plans. While the presumptive standard determined by the EPA is the
starting point for a state's standards of performance in its state
plan, a state may choose to take into account remaining useful life and
other factors in applying a standard of performance to a particular
source, consistent with the CAA, the EPA's implementing regulations,
and the final EG. The EG codified in 40 CFR part 60, subpart OOOOc,
applies to States in the development, submittal, and implementation of
State plans to establish performance standards to reduce emissions of
GHGs from designated facilities that are existing sources on or before
December 6, 2022. Under the Tribal Authority Rule, eligible Tribes may
seek approval to implement a plan under CAA section 111(d) in a manner
similar to a State.\16\ Tribes may, but are not required to, seek
approval for treatment in a manner similar to a State to develop Tribal
implementation plans (TIPs) implementing the EG codified in 40 CFR part
60, subpart OOOOc. The Tribal Authority Rule authorizes Tribes to
develop and implement their own air quality programs, or portions
thereof, under the CAA. However, it does not require Tribes to develop
a CAA program. Tribes may implement programs that are most relevant to
their air quality needs. If a Tribe does not seek and obtain the
authority from the EPA to establish a TIP, the EPA has the authority to
establish a Federal CAA section 111(d) plan for designated facilities
that are located in areas of Indian country.\17\ A Federal plan would
apply to all designated facilities located in the areas of Indian
country covered by the Federal plan unless and until the EPA approves a
TIP applicable to those facilities.
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\16\ See 40 CFR part 49, subpart A.
\17\ See the EPA's website, <a href="https://www.epa.gov/tribal/tribes-approved-treatment-state-tas">https://www.epa.gov/tribal/tribes-approved-treatment-state-tas</a>, for information on those Tribes that
have treatment as a State for specific environmental regulatory
programs, administrative functions, and grant programs.
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B. Availability of This Document and Other Related Information

In addition to being available in the docket, at Docket ID No. EPA-
HQ-OAR-2025-0163 located at <a href="https://www.regulations.gov">https://www.regulations.gov</a>, an electronic
copy of this action is available on the internet at <a href="https://www.epa.gov/controlling-air-pollution-oil-and-natural-gas-operations">https://www.epa.gov/controlling-air-pollution-oil-and-natural-gas-operations</a>. A
brief summary of this proposed rule may be found at
<a href="http://www.regulations.gov">www.regulations.gov</a>, Docket ID No. EPA-HQ-OAR-2025-0163. Following
publication in the Federal Register, the EPA will post the Federal
Register version of the proposal and key technical documents at this
same website.
A memorandum showing the edits that would be necessary to
incorporate the changes to 40 CFR Part, 60 subparts KKK, OOOO, OOOOa,
OOOOb and OOOOc proposed in this action is available in the docket
(Docket ID No. EPA-HQ-OAR-2025-0163). Following signature by the
Administrator, the EPA also will post a copy of this document to
<a href="https://www.epa.gov/controlling-air-pollution-oil-and-natural-gas-operations">https://www.epa.gov/controlling-air-pollution-oil-and-natural-gas-operations</a>.

C. Purpose of This Regulatory Action

On March 8, 2024, the EPA finalized NSPS for GHG and VOC emissions
from new, modified, and reconstructed sources in this source category,
codified

[[Page 68240]]

in 40 CFR 60, subpart OOOOb (NSPS OOOOb) as well as EG for GHG
emissions from existing sources in this source category, codified in
401 CFR 60, subpart OOOOc (EG OOOOc).
Prior to the March 2024 Final Rule, NSPS Subparts for this source
category underwent multiple rounds of major policy revisions, technical
amendments, and congressional actions. For example, NSPS OOOO (2012)
applied only to VOC and sulfur dioxide emissions from new, modified,
and reconstructed sources mainly in the upstream oil and gas sector.
Although methane wasn't directly regulated, many upstream controls that
targeted VOCs--like green completions, tank vapor control, and low-
bleed pneumatics--also reduced methane as a co-benefit (``co-
control''). In 2016, NSPS OOOOa added methane as a regulated pollutant
and expanded coverage to include the midstream, adding requirements for
transmission and storage, and additional source types (e.g., leak
detection and repair (LDAR) at well sites and compressor stations,
pneumatic pumps, compressors, hydraulically fractured oil wells). In
2020, EPA issued a rule titled, ``Oil and Natural Gas Sector: Emission
Standards for New, Reconstructed, and Modified Sources Review,''
September 14, 2020 (2020 Policy Rule), which removed the transmission
and storage segment from the NSPS OOOO and OOOOa, rescinding VOC and
methane emissions standards for that segment, and rescinded methane
emissions standards for the production and processing segments.
However, a joint congressional resolution disapproved the 2020 Policy
Rule.
More recently, in 2024, NSPS OOOOb clarified the scope and coverage
for addressing liquids unloading and certain intermittent emissions and
added more stringent standards and methods, such as zero-emitting
pneumatics, limits on routine flaring of associated gas at new oil
wells, stronger LDAR with advanced detection options, tighter
compressor requirements, and a super-emitter response program.
After publication of the March 2024 Final Rule, the EPA received,
and continued to receive, multiple petitions for reconsideration.\18\
Additionally, following Executive Orders 14154 (Unleashing American
Energy), 14156 (Declaring a National Energy Emergency), and Executive
Order 14192 (Unleashing Prosperity through Deregulation), the EPA
announced plans for deregulatory actions intended, among other things,
to unleash American energy and advance national energy policy
goals.\19\ Against the backdrop of these Executive Orders, the EPA
Administrator publicly announced reconsideration of the regulations in
40 CFR part 60, subparts OOOOb and OOOOc, in the March 2024 Final
Rule.\20\ As explained in further detail below, as a result of the
EPA's thorough examination of the March 2024 Final Rule, the Agency has
identified several aspects of the March 2024 Final Rule that merit
proposed substantive regulatory changes.
---------------------------------------------------------------------------

\18\ See Docket No. EPA-HQ-OAR-2025-0163 for petitions for
reconsideration received.
\19\ EPA Press Release: EPA Launches Biggest Deregulatory Action
in U.S. History. <a href="https://www.epa.gov/newsreleases/epa-launches-biggest-deregulatory-action-us-history">https://www.epa.gov/newsreleases/epa-launches-biggest-deregulatory-action-us-history</a>. March 12, 2025.
\20\ EPA Press Release: Trump EPA Announces OOOO b/c
Reconsideration of Biden-Harris Rules Strangling American Energy
Producers. <a href="https://www.epa.gov/newsreleases/trump-epa-announces-oooo-bc-reconsideration-biden-harris-rules-strangling-american">https://www.epa.gov/newsreleases/trump-epa-announces-oooo-bc-reconsideration-biden-harris-rules-strangling-american</a>.
March 12, 2025.
---------------------------------------------------------------------------

In this proposed rule, the EPA proposes targeted amendments to the
NSPS and EG for Existing Sources for the Crude Oil and Natural Gas
Source Category, partially in response to issues raised in petitions to
reconsider the March 2024 Final Rule. While the purpose of this
rulemaking is not intended to respond to all petitioner requests, the
EPA addresses several petitioner requests in this rulemaking. If a
petitioner request is not addressed in this rulemaking, that does not
mean that EPA will not address the petitioner request in the future.

D. Statutory Background and Authority

CAA section 111 authorizes the EPA to list and regulate categories
of stationary sources that the Administrator, ``in his judgment,''
finds that the source category ``causes, or contributes significantly
to, air pollution which may reasonably be anticipated to endanger
public health or welfare.'' \21\ The listing of a source category
triggers an obligation to promulgate ``standards of performance'' for
new sources and, under limited circumstances, to prescribe regulations
under which States submit plans that establish standards of performance
for existing sources.\22\ This provision, along with agencies'
authority to reconsider prior regulations, provides the EPA's statutory
authority for this proposed action.\23\
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\21\ 42 U.S.C. 7411(b)(1)(A).
\22\ 42 U.S.C. 7411(b), (d).
\23\ See FDA v. Wages & White Lion Invs., LLC, 604 U.S. 542, 568
(2025); FCC v. Fox TV Stations, Inc., 556 U.S. 502, 517-18 (2009);
Motor Vehicle Mfrs. Ass'n v. State Farm Mut. Auto. Ins. Co., 463
U.S. 29, 41-42 (1983); see also Clean Air Council v. Pruitt, 862
F.3d 1, 8 (D.C. Cir. 2017) (``Agencies obviously have broad
discretion to reconsider a regulation at any time.'').
---------------------------------------------------------------------------

CAA section 111(b)(1)(A) authorizes the Administrator to publish,
and from time-to-time revise, a list of categories of stationary
sources that the Administrator, ``in his judgment,'' finds ``causes, or
contributes significantly to, air pollution which may reasonably be
anticipated to endanger public health or welfare.'' Once the EPA lists
a source category under CAA section 111(b)(1)(A), the EPA must, under
CAA section 111(b)(1)(B), establish ``standards of performance'' for
``new sources'' in the source category. These standards are referred to
as NSPS. The NSPS are national requirements that apply directly to new
sources within the relevant source category.
Congress intended the NSPS to work together with the geography-
based national ambient air quality standards (NAAQS) program in CAA
sections 107-110. Similar to national emission standards for hazardous
air pollutants (NESHAPs) that limit emissions of hazardous air
pollutants (HAPs) listed and regulated under CAA section 112, NSPS
under CAA section 111 apply to a new source regardless of whether the
area in which the new source is located is subject to NAAQS-related
limitations and requirements. Accordingly, CAA section 111(a)(2)
defines a ``new source'' as ``any stationary source, the construction
or modification of which is commenced after the publication of
regulations (or, if earlier, proposed regulations) prescribing a
standard of performance under this section, which will be applicable to
such source.'' CAA section 111(a)(4) further defines ``modification''
as ``any physical change in, or change in the method of operation of, a
stationary source which increases the amount of any air pollutant
emitted by such source or which results in the emission of any air
pollutant not previously emitted.'' While this provision treats
modified sources as new sources, the EPA's regulations also treat a
source that undergoes ``reconstruction,'' by substantially replacing
its components, as a new source.\24\
---------------------------------------------------------------------------

\24\ 40 CFR 60.15.
---------------------------------------------------------------------------

CAA section 111(a)(1) defines ``standard of performance'' as ``a
standard for emissions of air pollutants'' that must be promulgated or
revised in a specified manner. When the EPA establishes or revises a
performance standard, CAA section 111(a)(1) provides that such standard
must ``reflect[] the degree of emission limitation achievable through
the application of the best system of emission reduction which (taking
into account the cost of achieving such

[[Page 68241]]

reduction and any nonair quality health and environmental impact and
energy requirements) the Administrator determines has been adequately
demonstrated.'' Thus, the term ``standard of performance'' as used in
CAA section 111 makes clear that the foundation for the regulatory
requirements for the source category is the EPA's determination of the
BSER that is ``adequately demonstrated'' for emissions of the relevant
air pollutants.\25\ The EPA has discretion in determining the BSER, and
has historically followed a ``technology-based approach'' that focuses
on ``measures that improve the pollution performance of individual
sources,'' such as ``add-on controls.'' \26\
---------------------------------------------------------------------------

\25\ West Virginia v. EPA, 597 U.S. 697, 709 (2022).
\26\ See id. at 727 (quoting an EPA rule).
---------------------------------------------------------------------------

To determine the BSER, the EPA first identifies the ``system[s] of
emission reduction'' that are ``adequately demonstrated'' and then
determines the ``best'' of those adequately demonstrated systems,
``taking into account'' factors including ``cost,'' ``nonair quality
health and environmental impact,'' and ``energy requirements.'' After
determining the BSER, the EPA derives from that system an
``achievable'' ``degree of emission limitation.'' A standard of
performance is ``achievable'' if a technology can reasonably be
projected to be available to an individual source at the time it is
constructed so as to allow it to meet the standard.\27\ The EPA must
then, under CAA section 111(b)(1)(B), promulgate ``standard[s] for
emissions''--the NSPS--that reflect that level of stringency. The EPA
may determine that different sets of sources have different
characteristics relevant for determining the BSER for emissions of the
relevant air pollutants and may subcategorize sources accordingly.\28\
---------------------------------------------------------------------------

\27\ Sierra Club v. Costle, 657 F.2d 298, 364 n.276 (D.C. Cir.
1981).
\28\ 42 U.S.C. 7411(b)(2).
---------------------------------------------------------------------------

To qualify as the BSER, the system of emission reduction must be
``adequately demonstrated'' as ``the Administrator determines.'' \29\
The plain text of CAA section 111(a)(1), and in particular the terms
``adequately'' and ``the Administrator determines,'' confers upon the
EPA the discretion to identify the appropriate system, including making
scientific and technological determinations and considering a broad
range of policy considerations.\30\ The D.C. Circuit has stated that
the EPA may weigh the various factors identified in the statute and
caselaw to determine the ``best'' system and has emphasized that the
EPA has significant discretion in weighing the factors (cost, health
and environmental impact, and energy requirements).\31\ The EPA has
broad discretion in determining which adequately demonstrated system of
emission reduction is the ``best.'' The D.C. Circuit has explained that
``section 111(a) explicitly instructs the EPA to balance multiple
concerns when promulgating a NSPS'' \32\ and emphasized that ``[t]he
text gives the EPA broad discretion to weigh different factors in
setting the standard,'' including the amount of emission reductions,
the cost of the controls, and the nonair quality environmental impacts
and energy requirements.\33\
---------------------------------------------------------------------------

\29\ 42 U.S.C. 7411(a)(1).
\30\ Nat'l Asphalt Pavement Ass'n v. Train, 539 F.2d 775, 786
(D.C. Cir. 1976); Essex Chem. Corp. v. Ruckelshaus, 486 F.2d 427,
434 (D.C. Cir. 1973).
\31\ Lignite Energy Council v. EPA, 198 F.3d 930, 933 (D.C. Cir.
1999) (``Because section 111 does not set forth the weight that
should be assigned to each of these factors, we have granted the
agency a great degree of discretion in balancing them.'').
\32\ Sierra Club v. Costle, 657 F.2d 298, 319 (D.C. Cir. 1981).
\33\ Id. at 321; see also New York v. Reilly, 969 F.2d 1147,
1150 (D.C. Cir. 1992).
---------------------------------------------------------------------------

CAA section 111(a)(1) requires the EPA to account for ``the cost of
achieving [the emission] reduction'' in determining the adequately
demonstrated BSER. Although the CAA does not describe how the EPA
should account for costs to affected sources, the D.C. Circuit has
formulated the cost standard in various ways, including by stating on
the upper bound that the EPA may not adopt a standard that the cost of
which would be ``excessive'' or ``unreasonable.'' \34\ The EPA has
discretion in considering cost under CAA section 111(a), both in
determining the appropriate level of costs and in balancing costs with
other BSER factors.\35\ The D.C. Circuit has repeatedly upheld the
EPA's consideration of cost in reviewing standards of performance.\36\
Regarding energy impacts, based on the D.C. Circuit's interpretations
of CAA section 111, this factor may also include the impact, if any, of
the air pollution controls on the energy supply for a particular area
or nationwide.\37\ Furthermore, the EPA has considered under this
statutory factor whether possible controls would create risks to the
reliability of the national electricity system.\38\
---------------------------------------------------------------------------

\34\ Sierra Club, 657 F.2d at 343; id. at 383 (affirming a
standard that was achievable and not ``unreasonably costly''); see
79 FR 1430, 1464 (January 8, 2014); Lignite Energy Council, 198 F.3d
at 933 (costs may not be ``exorbitant''); Portland Cement Ass'n v.
Train, 513 F.2d 506, 508 (D.C. Cir. 1975) (noting with approval the
EPA's conclusion that ``where the costs of meeting standards greater
than the industry could bear and survive, such standards could not
be implemented by the industry regardless of technological
feasibility'').
\35\ Sierra Club, 657 F.2d at 343.
\36\ See Essex Chem. Corp., 486 F.2d at 440; Portland Cement
Ass'n v. Ruckelshaus, 486 F.2d 375, 387-88 (D.C. Cir. 1973); Sierra
Club, 657 F.2d at 313.
\37\ See Sierra Club, 657 F.2d at 327-28 (quoting 44 FR 33580,
33583-84 (June 11, 1979)); 79 FR 1430, 1465 (January 8, 2014)
(citing Sierra Club, 657 F.2d at 351).
\38\ See 89 FR 39886 (May 9, 2024).
---------------------------------------------------------------------------

The EPA has generally used CAA section 111 to establish NSPS for
emissions of specified air pollutants from new sources within a
category. In the rare instances in which the new stationary source
standards concern air pollutants that are not regulated under the NAAQS
program pursuant to CAA sections 108-110, or the NESHAP program
pursuant to CAA section 112, the statute provides a separate authority
for addressing emissions of such air pollutants from existing sources
in the source category.\39\ CAA section 111(a)(6) defines an ``existing
source'' as ``any stationary source other than a new source.''
---------------------------------------------------------------------------

\39\ 42 U.S.C. 7411(d)(1)(A)(i)-(ii); see West Virginia, 597
U.S. at 710 (``Section 111(d) thus `operates as a gap-filler,'
empowering EPA to regulate harmful emissions not already controlled
under the Agency's other authorities. . . . Reflecting the ancillary
nature of Section 111(d), EPA has used it only a handful of times
since the enactment of the statute in 1970.'').
---------------------------------------------------------------------------

In contrast to the national regime for new sources under CAA
section 111(b), CAA section 111(d) establishes a framework of
``cooperative federalism for the regulation of existing sources.'' \40\
CAA section 111(d)(1) provides that when air pollutants covered by an
NSPS for a source category are not already encompassed within the NAAQS
program or NESHAP program, the EPA ``shall prescribe regulations which
shall establish a procedure similar to that provided by'' CAA section
110 ``under which each State shall submit to the Administrator'' a plan
for addressing emissions of such air pollutants by existing sources
within such source category.\41\ Reference to CAA section 110
incorporates the statute's provision for State submission and EPA
review of state implementation plans (SIPs) that provide for the
implementation, maintenance, and enforcement of the NAAQS for the areas
within such State.\42\ In a comparable manner, State plans required by
the regulations authorized in CAA section 111(d) must

[[Page 68242]]

``establis[h] standards of performance for any existing stationary
source'' for the air pollutant at issue and ``provid[e] for the
implementation and enforcement of such standards of performance.''
---------------------------------------------------------------------------

\40\ Am. Lung Ass'n v. EPA, 985 F.3d 914, 931 (D.C. Cir. 2021),
rev'd in part sub nom. West Virginia, 597 U.S. 697.
\41\ 42 U.S.C. 7411(d)(1). CAA section 111(a)(6) defines an
``existing source'' as ``any stationary source other than a new
source.'' 42 U.S.C. 7411(a)(6).
\42\ 42 U.S.C. 7410.
---------------------------------------------------------------------------

In the relatively few instances in which the EPA applies this
provision, the Agency generally promulgates ``emission guidelines''
that identify the BSER and the degree of emission limitation achievable
through the application of the BSER. (represented in EG OOOOc via
presumptive standards in a model rule). The EPA's regulations then
require States to establish standards of performance for emissions of
the air pollutant at issue by covered sources that reflect that level
of stringency. States need not compel regulated sources to adopt the
particular components of the BSER itself (or the model rule or
presumptive standards); rather, States have discretion in designing the
policies and rules used to achieve the degree of emission limitation
required by the EPA's emission guidelines. The statute requires the
EPA's regulations to permit a State, ``in applying a standard of
performance to any particular source,'' to ``take into consideration,
among other factors, the remaining useful life of the existing source
to which such standard applies.'' \43\
---------------------------------------------------------------------------

\43\ 42 U.S.C. 7411(d)(1).
---------------------------------------------------------------------------

Once the EPA approves a State's plan, the provisions in the plan
become federally enforceable in the same manner as the provisions of an
approved SIP under the CAA.\44\ If a State elects not to submit a plan
or submits a plan that the EPA does not find ``satisfactory,'' the
Agency is authorized to promulgate a plan that establishes Federal
standards of performance for the state's existing sources.\45\ In
establishing Federal standards of performance for existing sources
under these circumstances, the EPA must ``take into consideration,
among other factors, remaining useful lives of the sources in the
category of sources to which such standard applies.'' \46\
---------------------------------------------------------------------------

\44\ 42 U.S.C. 7411(d)(2)(B).
\45\ 42 U.S.C. 7411(d)(2)(A).
\46\ 42 U.S.C. 7411(d)(2).
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E. Regulatory History and Background of NSPS and EG for the Crude Oil
and Natural Gas Source Category

The EPA has regulated VOC emissions from the Crude Oil and Natural
Gas source category since 1985 when the EPA promulgated NSPS for the
Crude Oil and Natural Gas source category.\47\ That rule addressed VOC
emissions from equipment leaks at onshore natural gas processing plants
(40 CFR part 60, subpart KKK). On October 1, 1985, the EPA promulgated
additional NSPS for the source category to regulate sulfur dioxide
(SO<INF>2</INF>) emissions from onshore natural gas processing plants
(40 CFR part 60, subpart LLL).\48\ In 2012, the Agency expanded
requirements applicable to this source category by adding VOC standards
for several oil and natural gas related operations emission sources not
covered by 40 CFR part 60, subparts KKK and LLL, including natural gas
well completions, centrifugal and reciprocating compressors, certain
natural gas operated pneumatic controllers in the production and
processing segments of the industry, and storage vessels in the
production, processing, and transmission and storage segments.
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\47\ 50 FR 26122 (June 24, 1985).
\48\ 50 FR 40158 (October 1, 1985).
---------------------------------------------------------------------------

For the first time in 2016, the Agency established requirements for
certain equipment, processes, and operations across the Oil and Natural
Gas Industry, including in the production, processing, and transmission
and storage segments to address both GHG emissions (in the form of
methane) in response to global climate change concerns, and VOCs.\49\
---------------------------------------------------------------------------

\49\ 81 FR 35832 (June 3, 2016).
---------------------------------------------------------------------------

In September 2020, the EPA published two final rules to amend 2012
NSPS OOOO and 2016 NSPS OOOOa. The first is titled, ``Oil and Natural
Gas Sector: Emission Standards for New, Reconstructed, and Modified
Sources Review.'' \50\ Commonly referred to as the 2020 Policy Rule, it
first rescinded the regulations applicable to the transmission and
storage segment on the basis that the 1979 listing limited the source
category to the production and processing segments and that the
transmission and storage segment is not ``sufficiently related'' to the
production and processing segments, and therefore cannot be part of the
same source category.\51\ In addition, the 2020 Policy Rule rescinded
methane requirements for the industry's production and processing
segments on two separate bases. The first was that such standards are
redundant to VOC standards for these segments.\52\ The second was that
the rule interpreted CAA section 111 to require, or at least authorize
the Administrator to require, a pollutant specific ``significant
contribution finding'' as a prerequisite to a NSPS for a pollutant, and
to require that such finding be supported by some identified standard
or established set of criteria for determining which contributions are
``significant.'' \53\ The rule went on to conclude that the alternative
significant contribution finding that the EPA made in the 2016 Rule for
GHG emissions was flawed because it accounted for emissions from the
transmission and storage segment and because it was not supported by
criteria or a threshold.54 55
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\50\ 85 FR 57018 (September 14, 2020).
\51\ See 85 FR 57027, 57029 (September 14, 2020).
\52\ 85 FR at 57030 (September 14, 2020).
\53\ 85 FR at 57034 (September 14, 2020).
\54\ 85 FR 57038 (September 14, 2020).
\55\ Following the promulgation of the 2020 Policy Rule, the EPA
promulgated a final rule that identified a standard or criteria for
determining which contributions are ``significant,'' which the D.C.
Circuit vacated and remanded at the Agency's request following a
change in administration. ``Pollutant-Specific Significant
Contribution Finding for Greenhouse Gas Emissions From New,
Modified, and Reconstructed Stationary Sources: Electric Utility
Generating Units, and Process for Determining Significance of Other
New Source Performance Standards Source Categories.''86 FR 2542
(January 13, 2021), vacated by California v. EPA, No. 21-1035 (D.C.
Cir.) (Order, April 5, 2021, Doc. #1893155).
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Published on September 15, 2020, the second of the two rules is
titled ``Oil and Natural Gas Sector: Emission Standards for New,
Reconstructed, and Modified Sources Reconsideration.'' \56\ Commonly
referred to as the 2020 Technical Rule, this second rule made further
amendments to the 2016 NSPS OOOOa following the 2020 Policy Rule to
eliminate or reduce certain monitoring obligations and to address a
range of issues in response to administrative petitions for
reconsideration and other technical and implementation issues brought
to the EPA's attention since the 2016 NSPS OOOOa rulemaking.
Specifically, the 2020 Technical Rule exempted low production well
sites from fugitives monitoring (previously required semiannually),
required semiannual monitoring at gathering and boosting compressor
stations (previously quarterly), streamlined recordkeeping and
reporting requirements, allowed compliance with certain equivalent
State requirements as an alternative to NSPS fugitive requirements,
streamlined the application process to request the use of new
technologies to monitor for fugitive emissions, addressed storage tank
batteries for applicability determination purposes and finalized
several technical corrections. Because the 2020 Technical Rule was
issued the day after the EPA's rescission of methane regulations in the
2020 Policy Rule, the amendments made in the 2020 Technical Rule
applied only to the requirements to regulate VOC emissions from this
source category. The 2020 Policy Rule amended 40 CFR part 60, subparts

[[Page 68243]]

OOOO and OOOOa, as finalized in 2016. The 2020 Technical Rule amended
the 40 CFR part 60, subpart OOOOa, as amended by the 2020 Policy Rule.
The joint resolution disapproving the 2020 Policy Rule did not include
or address the 2020 Technical Rule.
---------------------------------------------------------------------------

\56\ 85 FR 57398 (September 15, 2020).
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On November 15, 2021, the EPA published a proposed rule (``November
2021 Proposal'') aimed at reducing GHG and VOC emissions from parts of
the oil and natural gas industry,\57\ specifically the Crude Oil and
Natural Gas source category.58 59 In the November 2021
Proposal, the EPA proposed new and updated standards of performance
under CAA section 111(b) for GHGs (in the form of methane limitations)
and VOC emissions from new, modified, and reconstructed sources
(affected facilities) in this source category, as well as revisions to
standards of performance for GHGs and VOC emissions already codified at
40 CFR part 60, subparts OOOO and OOOOa. The November 2021 Proposal
also proposed EG under CAA section 111(d) for GHGs emissions (in the
form of methane limitations) from existing sources (designated
facilities).\60\ The EPA also proposed several related actions in the
November 2021 Proposal to address issues related to congressional
disapproval of the 2020 Policy Rule under the Congressional Review Act
in 2021. Lastly, in the November 2021 Proposal, the EPA proposed a
protocol for OGI under the general provisions of 40 CFR part 60.
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\57\ The EPA characterizes the oil and natural gas industry
operations as being generally composed of four segments: (1)
Extraction and production of crude oil and natural gas (``oil and
natural gas production''), (2) natural gas processing, (3) natural
gas transmission and storage, and (4) natural gas distribution. 89
FR 16841.
\58\ Standards of Performance for New, Reconstructed, and
Modified Sources and Emissions Guidelines for Existing Sources: Oil
and Natural Gas Sector Climate Review; Proposed Rule, 86 FR 63110
(November 15, 2021).
\59\ The EPA defines the Crude Oil and Natural Gas source
category to mean: (1) Crude oil production, which includes the well
and extends to the point of custody transfer to the crude oil
transmission pipeline or any other forms of transportation; and (2)
natural gas production, processing, transmission, and storage, which
include the well and extend to, but do not include, the local
distribution company custody transfer station, commonly referred to
as the ``city-gate.'' 89 FR 16848.
\60\ The term ``designated facility'' is defined as ``any
existing facility . . . which emits a designated pollutant and which
would be subject to a standard of performance for that pollutant if
the existing facility were an affected facility.'' 40 CFR 60.21a(b).
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On December 6, 2022, the EPA published a supplemental proposed rule
(``December 2022 Supplemental Proposal'') that was composed of two main
additions.\61\ First, the EPA proposed further updates to NSPS OOOOb
standards compared to those proposed in the November 2021 Proposal
under CAA section 111(b) for GHGs (in the form of methane limitations)
and VOC emissions from new, modified, and reconstructed facilities.
Second, the EPA proposed further updates to the presumptive standards
compared to those proposed for EG OOOOc in the November 2021 Proposal
as part of the CAA section 111(d) EG for GHG emissions (in the form of
methane limitations) from designated facilities. For purposes of EG
OOOOc, the EPA also proposed implementation requirements for State
plans developed to limit GHG pollution (in the form of methane
limitations) from designated facilities in the Crude Oil and Natural
Gas source category under CAA section 111(d).
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\61\ Standards of Performance for New, Reconstructed, and
Modified Sources and Emissions Guidelines for Existing Sources: Oil
and Natural Gas Sector Climate Review; Supplemental Notice of
Proposed Rulemaking, 87 FR 74702 (December 6, 2022).
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On March 8, 2024, the EPA published the March 2024 Final Rule with
multiple separate actions intended to reduce GHG and VOC emissions from
the Crude Oil and Natural Gas source category.\62\ First, the EPA
finalized NSPS OOOOb regulating GHG (in the form of a limitation on
emissions of methane) and VOC emissions for the Crude Oil and Natural
Gas source category pursuant to CAA section 111(b). The NSPS codified
in 40 CFR part 60, subpart OOOOb, are directly applicable to affected
facilities that begin construction, reconstruction, or modification
after December 6, 2022. Second, the EPA finalized the EG in OOOOc to
limit GHG emissions. The EG codified in 40 CFR part 60, subpart OOOOc,
applies to States in the development, submittal, and implementation of
State plans to establish performance standards to reduce emissions of
GHGs from designated facilities that are existing sources on or before
December 6, 2022. Third, the EPA finalized several related actions
(including final amendments to NSPS OOOOa stemming from congressional
disapproval of the 2020 Policy Rule under the Congressional Review Act
in 2021. Fourth, the EPA finalized a protocol under the General
Provisions for OGI. The March 2024 Final Rule became effective on May
7, 2024, 60 days after publication in the Federal Register.
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\62\ 89 FR 16820 (March 8, 2024).
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On August 1, 2024, the EPA published an IFR that made minor and
non-substantive corrections to the March 2024 Final Rule in order to
correct identified inadvertent errors.\63\ After publication of the
March 2024 Final Rule, the EPA identified, through its own internal
reassessment of the regulatory text, as well as through communications
with stakeholders and the Office of the Federal Register, erroneous
cross-references and typographical errors within the regulatory text.
Through those same processes, the EPA also identified the need for some
minor wording changes to clarify erroneous language (or, in some cases,
erroneous omissions) in the regulatory text, and to ensure that the
regulatory text aligns with the descriptions of the relevant provisions
in the March 2024 Final Rule preamble and other parts of the
regulation(s).
---------------------------------------------------------------------------

\63\ 89 FR 62872 (August 1, 2024).
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Further, after the publication of the March 2024 Final Rule, the
EPA received multiple petitions for reconsideration.\64\ On May 6,
2024, the EPA notified certain petitioners and the public that
reconsideration had been granted on two narrow and discrete aspects of
the March 2024 Final Rule: The temporary flaring provisions for
associated gas in certain situations; and the vent gas NHV continuous
monitoring requirements an alternative performance test (sampling
demonstration) option for flares and enclosed combustion devices.\65\
On January 15, 2025, the EPA proposed amendments for this
Reconsideration and finalized amendments for this Reconsideration on
April 9, 2026.66 67
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\64\ See Docket No. EPA-HQ-OAR-2025-0163 for petitions for
reconsideration received.
\65\ See Docket No. EPA-HQ-OAR-2025-0163 for May 6, 2024, letter
granting reconsideration.
\66\ 90 FR 3743 (January 15,2025).
\67\ 91 FR 18056 (April 9, 2026).
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On July 31, 2025, the EPA issued an IFR that extended deadlines for
certain provisions related to control devices, equipment leaks, storage
vessels, process controllers, and covers and CVS in the NSPS OOOOb.\68\
The EPA also extended the date for future implementation of the Super
Emitter Program. Finally, the EPA extended the State plan submittal
deadline in the EG OOOOc. On December 3, 2025, the EPA promulgated a
final rule reaffirming the extensions established in the July 2025 IFR,
which extended several compliance deadlines in the NSPS OOOOb and EG
OOOOc.\69\ In addition to reaffirming the extensions in the July 2025
IFR, the EPA further extended the deadline for the NHV continuous
monitoring requirements and for the alternative performance test
(sampling demonstration) option for flares and

[[Page 68244]]

enclosed combustion devices and also extended the compliance deadline
related to the initial annual reporting deadline.
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\68\ 90 FR 35966 (July 31, 2025).
\69\ 90 FR 55671 (December 3, 2025).
---------------------------------------------------------------------------

This proposal is based on a record-focused reevaluation of certain
determinations made in the March 2024 Final Rule. The EPA is proposing
this action to provide near-term relief from certain regulatory
requirements it now believes are predicated on erroneous BSER
determinations, are not achievable, and/or are otherwise unreasonable.
Addressing these issues in the near term is necessary to provide much
needed clarity to new sources regulated under NSPS OOOOb, and to
existing sources that will be subject to state plans under EG OOOOc,
given the compliance deadlines and implementation schedules set in the
March 2024 Final Rule, as subsequently extended.
The EPA acknowledges that stakeholders have also raised concerns
about the Agency's underlying statutory authority to regulate GHG
emissions from the Oil and Natural Gas source category under CAA
section 111. In a separate and ongoing rulemaking for a distinct source
category, the Agency is addressing statutory authority issues
associated with its regulation of GHG emissions from fossil fuel-fired
power plants under CAA section 111.\70\ That rulemaking raises issues
with respect to the scope of the Agency's authority under CAA section
111 but does not encompass or address NSPS or EG for the Crude Oil and
Natural Gas source category, which operate in a distinct manner, have
their own regulatory history, and involve different and additional
considerations. Pending completion of the separate rulemaking
addressing the EPA's statutory authority with respect to GHG emissions
from the fossil fuel-fired power plant source category, the Agency
would then address in a future rulemaking, as appropriate, the extent
to which the conclusions in such action with respect to the Agency's
statutory authority under CAA section 111 require revisions to the oil
and gas regulations at 40 CFR part 60, subparts OOOOa, OOOOb and OOOOc.
---------------------------------------------------------------------------

\70\ See 91 FR 59002 (September 17, 2026); 90 FR 25752 (June 17,
2025). The EPA recently finalized a record-focused reevaluation and
repeal of certain BSER determinations and associated standards for
fossil fuel-fired power plants based on the alternative proposal
presented in the June 2025 proposed rule. See 91 FR 58954 (September
17, 2026). The EPA has not yet taken final action on the primary
proposal in the June 2025 proposal rule and intends to consider the
statutory authority issues raised in that aspect of the proposed
rule together with statutory authority issues raised in the Agency's
recent supplemental proposal in a forthcoming final action
addressing the Agency's authority to regulate GHG emissions from the
fossil fuel-fired power plant source category.
---------------------------------------------------------------------------

III. Summary and Rationale of Proposed Amendments to NSPS OOOOb and EG
OOOOc

Sections III.A through III.K of this preamble present the
background, the summary of proposed changes, and rationale for proposed
amendments to the March 2024 Final Rule.

A. Super Emitter Program

As part of the March 2024 Final Rule, the EPA established a novel
form of work-practice standard and compliance assurance mechanism known
as the Super Emitter Program, which relies on third-party entities
certified by the Agency to detect ``very large emissions events'' \71\
using Agency-approved technologies and submit notifications to EPA
personnel. The EPA transmits the third-party notification to relevant
owners and operators, thereby triggering an obligation to investigate
and to take any necessary corrective actions required under applicable
standards. The EPA finalized this program as part of the 40 CFR part 60
NSPS subparts OOOO, OOOOa, and OOOOb and as part of the presumptive
requirements applicable to state plans under EG OOOOc, meaning that
States are expected to establish super emitter programs analogous to
the EPA's. Upon reconsideration, the EPA no longer believes that the
Super Emitter Program is well-grounded in policy and law and proposes
to rescind the third-party certification, notification, and other
related provisions in NSPS OOOO, OOOOa, and OOOOb and EG OOOOc.
---------------------------------------------------------------------------

\71\ 89 FR 16825 (March 8, 2024).
---------------------------------------------------------------------------

In Section III.A.1 of this preamble, the EPA explains its initial
conception of the program in the December 2022 Supplemental Proposal,
comments received on this initial conception, and changes made to the
program by the Agency in the March 2024 Final Rule. In Section III.A.2,
the EPA explains the multiple potential bases for the proposed
rescission of the Super Emitter Program. First, the EPA proposes to
rescind the Super Emitter Program on policy grounds, including because
the program has failed to meet the expectations the Agency had when it
finalized the program in March 2024 and is unnecessary and ineffective.
Second, the EPA also proposes to rescind the Super Emitter Program for
legal reasons. While the EPA solicits comment on this proposal within
this section, table 34 in section VII also summarizes all solicitations
for comment for convenience.
1. Background
In the December 2022 Supplemental Proposal, the EPA sought public
comment on a novel program intended ``to trigger swift mitigation of
super-emitter emissions events when they are identified through
credible information provided by regulatory authorities or approved
qualified third-party sources.'' \72\ The EPA explained that it
believed additional action was needed to address ``super-emitter
emissions events'' citing one study finding ``that the top five percent
of sources contribute over 50 percent of the total emissions'' from the
source category, although it also acknowledged that results ``vary by
basin.'' \73\ This program, referred to at the time as the ``super-
emitter response program,'' adopted the concept of ``Super-Emitters''--
sources for which detected emissions are 100 kilograms per hour (kg/hr)
or greater--and proposed a BSER of ``[r]oot cause analysis and
corrective action following notification of super-emitter emissions
event.'' \74\ The EPA believed that the proposed requirements in the
November 2021 Proposal and December 2022 Supplemental Proposal, ``when
implemented correctly, would result in reducing the number of super-
emitter emissions events,'' but further proposed the ``super emitter
response program as a backstop to address the large contribution of
super-emitters'' to sector emissions. The EPA proposed two statutory
bases for the program: first, that ``super-emitters'' are ``a separate
and distinct source of emissions'' (and therefore a ``designated
facility''); and second, that the program ``constitutes work practice
standards for certain sources and compliance assurance mechanisms for
other sources.'' \75\
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\72\ 87 FR 74706 (December 6, 2022); id. at 74706 n.5 (noting
that the November 2021 Proposal ``solicited comment on the use of
information collected by communities and others to address large
emissions events'').
\73\ 87 FR 74746 (December 6, 2022). Specifically, the EPA
relied upon a March 2022 aerial survey of methane emissions in the
New Mexico Permian Basin. See id. 74746 n.99 (citing Yuanlei Chen et
al., ``Quantifying Regional Methane Emissions in the New Mexico
Permian Basin with a Comprehensive Aerial Survey,'' Environmental
Science and Technology, Vol. 56, No. 7 (March 2022)).
\74\ 87 FR 74708, 74711 (December 6, 2022).
\75\ 87 FR 74712 n.9, 74752-54 (December 6, 2022).
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The proposed ``super emitter response program'' generated
significant public comment. As relevant here, certain commenters argued
that the EPA lacked statutory authority to treat super-emitter events
as an ``affected facility'' subject to standards separate and apart
from affected facilities subject, on their own terms, to either the
NSPS OOOO,

[[Page 68245]]

OOOOa, and OOOOb or EG OOOOc.\76\ Commenters raised concerns that this
first-of-its-kind program would create regulatory obligations based on
monitoring conducted by unaffiliated third parties, that the EPA had
not clearly explained an adequate legal basis for the proposed program,
and that the EPA had not explained how the program was consistent with
the statute's specific provision for citizen enforcement in CAA section
304.\77\ Commenters also argued that the EPA had not justified the 100
kg/hr threshold or explained how that threshold would work in practice
given the short duration of super-emitter events and attribution
difficulties.\78\
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\76\ API Comments on NSPS OOOOb and EG OOOOc 2022 Supplemental
Proposal. February 13, 2023. EPA-HQ-OAR-2021-0317-2428. pg 98; and
AXPC Comments on the 2022 Supplemental Proposal. February 13, 2023.
EPA-HQ-OAR-2021-0317-2326. pg. 28.
\77\ API Comments on NSPS OOOOb and EG OOOOc Supplemental
Proposal. February 13, 2023. EPA-HQ-OAR-2021-0317-2428. pg 97; Texas
Oil & Gas Association (TXOGA). (2022). ``Comments on New Source
Performance Standards and Emission Guidelines for Crude Oil and
Natural Gas Facilities: Climate Review; Proposed Rule.'' January,
31, 2022. Pgs. 32-33; and TXOGA Comments of the 2022 Supplemental
Proposal. EPA-HQ-OAR-2021-0317-2202. pg. 10.
\78\ API Comments on NSPS OOOOb and EG OOOOc Supplemental
Proposal. February 13, 2023. EPA-HQ-OAR-2021-0317-2428. pg. 99.
---------------------------------------------------------------------------

The EPA finalized the program, with revisions, as the Super Emitter
Program in the March 2024 Final Rule. The Agency reaffirmed its view
that the program would be an additional tool to address super-emitter
events, which it found may ``contribute almost 50 percent of the
methane emissions in the oil and gas sector.'' \79\ The Super Emitter
Program was thus designed to serve as a backstop and a complement to
other requirements of the NSPS OOOO, OOOOa, OOOOb, and EG OOOOc
regulatory program to address large methane super-emitter events by
directing operator attention to potential problems and to provide
feedback to the EPA about the effectiveness of other regulatory
requirements. The EPA defined a super-emitter event in 40 CFR part 60
subparts OOOO, OOOOa, OOOOb and EG OOOOc as ``any emissions event that
is located at or near an oil and natural gas facility (e.g., individual
well site, centralized production facility, natural gas processing
plant, or compressor station) and that is detected using remote
detection methods and has a quantified emission rate of 100 [kg/hr] of
methane or greater.'' \80\ In response to public comments, the EPA
clarified that its statutory authority for the program was CAA section
114(a), which authorizes the Agency to require `` `any person who owns
or operates any emission source' (except mobile sources) to provide
information necessary for purposes of carrying out the CAA and its
authority to regulate sources under CAA section 111.'' \81\ The EPA
further clarified that it would not treat super-emitter events as a
distinct ``affected facility'' but was instead finalizing that the
Super Emitter Program is ``an additional work practice standard . . .
for fugitive emissions at well sites, centralized production facilities
and compressor stations'' and as ``an additional compliance measure''
for ``affected facilities'' subject to NSPS OOOO, OOOOa, OOOOb, and EG
OOOOc.\82\
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\79\ 89 FR 16977 (March 8, 2024).
\80\ 40 CFR 60.5371, 60.5371a, 60.5371b, 60.5388c.
\81\ 89 FR 16877 (March 8, 2024) (quoting 42 U.S.C. 7414(a)).
\82\ Id.; see also id. at 16877-78.
---------------------------------------------------------------------------

The EPA made changes to the Super Emitter Program from proposal in
response to commenter objections about the role of unaffiliated third
parties. Where an identified super-emitter event is attributable to a
source regulated under CAA section 111 (NSPS OOOO, OOOOa, or OOOOb, or
a state or Federal plan implementing EG OOOOc), the owner or operator
is responsible for taking action in response to such notifications in
accordance with the applicable regulation. Rather than authorizing
certified third parties to send notifications to potential sources
directly, the final regulations instead route notifications through the
EPA in the first instance. Under 40 CFR 60.5398b(d), the EPA approves
the remote-sensing technologies that may be used to identify relevant
emissions events, and, consistent with the implementing regulations,
may certify and de-certify third party notifiers. Certified third party
notifiers may submit information to the EPA that they have collected
about potential super-emitter events using EPA-approved remote-sensing
technology in the form of a notification that is timely submitted and
contains certain specified information on the methane release.\83\ The
EPA then reviews the submission, and if it determines that the
submission is complete and does not contain information that it finds
to be inaccurate to a reasonable degree of certainty, the EPA will
provide the notification to the owner or operator of the relevant
facility and make the notification publicly available on an EPA
website, without owner or operator attribution.\84\ Under these
provisions, owners and operators of facilities who receive
notifications from the EPA who own or operate an oil and natural gas
facility within 50 meters from the latitude and longitude provided in
the notification, are required to initiate an investigation of any
identified potential large methane emissions events at their site,
report to the EPA the results of the investigation, and, if necessary,
repair any leaks covered by certain requirements. Owners and operators
of facilities who receive notifications from the EPA but who do not own
or operate an oil and natural gas facility within 50 meters from the
latitude and longitude provided in the notification, would report this
to the EPA and no further action is required.\85\ The EPA then posts
the reports from the owners and operators on the same EPA website,
including owner or operator attributions that were confirmed by the
report.\86\
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\83\ See 40 CFR 60.5371b.
\84\ Id.; see also 40 CFR 60.5371, 60.5371a, and 60.5388c.
\85\ See, e.g., 40 CFR 60.5371(a)(1), 60.5371a(a)(1),
60.5371b(d)(1), and 60.5388c(a)(1).
\86\ See, e.g., 40 CFR 60.5371b.
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Subsequent to the March 2024 Final Rule, several reconsideration
petitioners continued to raise concerns about the Super Emitter
Program. The EPA has received few requests for third party or
technology certification, and as explained further below, now agrees
with concerns raised during the prior rulemaking that the short
duration of such events and established threshold render the program
difficult to implement and ineffective at proactively addressing such
events. In addition to those concerns, the EPA has experienced
unanticipated difficulties and concerns in implementing this new
program. To address those concerns, the EPA included in the 2025 IFR an
extension of the date for future implementation of the Super Emitter
Program until January 22, 2027. In a final action published on December
3, 2025, the EPA considered public comments on the extensions for the
Super Emitter Program and reaffirmed the extensions.\87\
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\87\ 90 FR 55671 (December 3, 2025).
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2. Summary of Proposed Rescission and Rationales
The EPA is proposing to rescind the Super Emitter Program on
several alternative policy and legal bases. First, the EPA now proposes
that this novel program rests on insufficient evidence of the nature
and duration of super-emitter events, defined as emissions of 100 kg/hr
or greater, and that the same concerns that led the Agency to decline
to treat ``super emitters'' as a distinct ``affected source'' call into
question the

[[Page 68246]]

conceptual basis and need for the program in the first instance.
Second, the EPA further proposes that the program is not necessary and
provides limited additional value in light of the other requirements
applicable to affected sources under NSPS OOOO, OOOOa, OOOOb, and EG
OOOOc. Third, the EPA proposes that the Super Emitter Program is not
effective and is overly broad as designed. Fourth, the EPA proposes
that the statutory authority bases finalized in the March 2024 Final
Rule are inadequate to maintain the program. Specifically, as explained
below, the EPA has concerns that the program features an inappropriate
role for third parties, does not properly function as a work practice
standard, and does not properly function as a compliance measure.
If finalized, the proposed rescission would remove provisions
related to the Super Emitter Program, including for certification and
decertification of third parties, certification and decertification of
third-party monitoring technologies, and a source's obligations to
respond in the event of a notification received pursuant to the Super
Emitter Program, from 40 CFR part 60, subparts OOOO, OOOOa, OOOOb, and
OOOOc.
The EPA proposes that additional information and further study are
required to evaluate the underlying premise of the Super Emitter
Program, that is, the assertion that ``super-emitter events'' (defined
as emissions of 100 kg/hr or greater) from a select few sources are
responsible for the majority of source-category emissions. In the March
2024 Final Rule, and specifically in the December 2022 Supplemental
Proposal, the EPA believed that ``the top five percent of sources
contribute to over 50 percent of the total emissions'' from the source
category because of super-emitter events.\88\ For this conclusion, the
Agency relied on a single study consisting of 2018-2020 aerial surveys
of the New Mexico Permian Basin that acknowledged its results departed
from those in previous studies and did not endeavor to differentiate
among the regulatory status of emission sources or potential causes for
the emissions. While informative, the novel analytical approach and
results of this study had not been thoroughly vetted at the time of the
December 2022 Supplemental Proposal, and the EPA did not revisit the
question of the study's quality and utility in the March 2024 Final
Rule. Indeed, the Agency acknowledged at the time that results vary by
basin and involve a number of different potential causes and
explanations depending on the nature and regulatory status of the
potential source(s).\89\ At the time of the March 2024 Final Rule, the
EPA did not have adequate information on the prevalence, nature,
duration, and cause of large emission events, without which the program
cannot effectively further legitimate policy ends, and thus, the EPA
proposes to rescind the Super Emitter Program. While the Agency is
aware of some additional information that has become available on this
topic since the March 2024 Final Rule, the Agency proposes to conclude
that information indicates that the Super Emitter Program is overly
broad as designed, as explained below, which is a separate reason for
its proposed rescission. The Agency specifically seeks comment
providing additional studies and information bearing on super-emitter
events and corresponding strategies to address them, including whether
the EPA should treat them separately as a regulatory manner in the
first instance and, if so, whether and which threshold the EPA should
use to separately consider such events. (Question III.1a)
---------------------------------------------------------------------------

\88\ 87 FR 74746-47 (December 6, 2022).
\89\ Id.
---------------------------------------------------------------------------

Separately, the EPA no longer believes that the Super Emitter
Program is necessary in light of the emission-limitation, monitoring,
and mitigation requirements applicable to affected sources. As
described in the record for the March 2024 Final Rule, the program was
finalized as an additional work practice standard under NSPS OOOOb (and
presumptive standard under EG OOOOc), and as an additional compliance
assurance measure for other NSPS OOOOb affected facilities, NSPS OOOO
and OOOOa affected facilities, and designated facilities under EG
OOOOc. The Agency asserted at the time that the program could be a
helpful supplement to requirements already applicable to affected
facilities because super-emitter events are unpredictable and may not
be detected immediately, and thus the Agency believed that providing
timely notifications of them to operators could assist in addressing
these events.\90\ However, the EPA also concluded that the NSPS
requirements and EG presumptive standards included in the March 2024
Final Rule would prevent large emission events (e.g., design and
operation requirements for flares) or detect and mitigate most of these
large emissions events (e.g., through regular monitoring for fugitive
emissions) \91\ and did not explain why the Super Emitter Program was
necessary as a work-practice standard or compliance assurance mechanism
for affected facilities already required to identify and correct
aberrant emissions events.
---------------------------------------------------------------------------

\90\ 87 FR 74748 (December 6, 2022).
\91\ 87 FR 74747 (December 6, 2022).
---------------------------------------------------------------------------

Even considering the amendments proposed in this proposed rule, the
EPA continues to believe that other requirements in the NSPS OOOOb and
the EG OOOOc will be more than sufficient to prevent, detect, and
mitigate most large emission events that would be within the scope of
the Super Emitter Program. Those requirements include, for example,
zero-emissions standards for process controllers at high production
sites and design and operation requirements for flares, combined with
regular monitoring for fugitive emissions, process upsets on tanks, and
malfunctioning controllers. For example, many of the persistent super-
emitter events identified in recent studies are from flares and tank
systems 92 93 and the other compliance assurance
requirements in the March 2024 Final Rule address several issues that
may lead to these types of large emission events. These include
compliance assurance requirements for flares and enclosed combustors
that include a requirement for a continuous burning pilot flame that
must be confirmed through monthly visual emissions testing or the
continuous use of video surveillance cameras.\94\ Real-time monitoring
or monthly testing is expected to be sufficient to detect
malfunctioning flares and support compliance with the applicable
requirements, making the possible detection of such emissions by a
third-party unnecessary from a compliance assurance perspective. As
these examples illustrate, provisions in the March 2024 Final Rule are
expected to prevent many such events and provide timely and actionable
information on events that would be within the scope of the Super
Emitter Program, as well as adequately supporting operators to identify
such events.
---------------------------------------------------------------------------

\92\ Cusworth, D.H. et al. (2026). Duration of super-emitting
oil and gas methane sources. Nat. Commun. 2026 Jan 24;17(1):2011.
doi: 10.1038/s41467-026-68804-7. PMID: 41580397; PMCID: PMC12936207.
<a href="https://pubmed.ncbi.nlm.nih.gov/41580397/">https://pubmed.ncbi.nlm.nih.gov/41580397/</a>.
\100\ Cusworth, D.H. et al. (2021). Intermittency of Large
Methane Emitters in the Permian Basin. Environ. Sci. Technol. Lett.
13 July 2021; 8(7): 567-573. <a href="https://doi.org/10.1021/acs.estlett.1c00173">https://doi.org/10.1021/acs.estlett.1c00173</a>.
\94\ The EPA is not proposing to amend these requirements in
this proposed rule.
---------------------------------------------------------------------------

Along with these provisions, the Alternative Test Method (ATM)
program is expected to further support the identification of super-
emitter events. Under that program, owners and operators have the
option to use EPA-approved advanced methane detection

[[Page 68247]]

and measurement systems to complete the required monitoring. There are
currently 18 approved alternative technologies that include periodic
airborne remote sensing surveys that can detect super-emitter events
and lower-level emissions with improved accuracy and source specificity
compared to most satellite techniques.\95\ Importantly, these survey
approaches provide actionable emission event data directly to the
operator, greatly reducing lag time associated with EPA notification
under the current Super Emitter Program. In addition to periodic
monitoring options, emerging semi-continuous monitoring approaches
utilizing 24/7 onsite sensing techniques may be able to provide rapid
detections of high emitter events yielding enhanced diagnostic
capability for operators. Because monitoring under the ATM program is
site specific, the emission information delivered is directly relevant
to the affected source categories. With monthly, bimonthly, or
quarterly monitoring requirements (depending on technology
sensitivity), the ATM program provides an effective check for super-
emitter events. Based on the ATM program application rate, the EPA
anticipates increased participation in the program over time, which can
support the timely identification of super-emitter events.
---------------------------------------------------------------------------

\95\ Information on EPA-approved alternative technologies can be
found at; <a href="https://www.epa.gov/emc/oil-and-gas-alternative-test-methods">https://www.epa.gov/emc/oil-and-gas-alternative-test-methods</a>.
---------------------------------------------------------------------------

In addition, the EPA no longer believes, given experience with
implementation of the program and the limited additional information in
the scientific literature, that the Super Emitter Program is effective
in addressing the events the Agency previously feared would not be
adequately captured or addressed by other requirements due to
implementation issues and the overly broad nature of its design. As
noted in the 2025 IFR, the EPA experienced unanticipated difficulties
and concerns in implementing the Super Emitter Program. In the 2025
IFR, the EPA explained that the third-party notifier is not required to
provide attribution of who owns or operates a site. In practice this
has meant the EPA needed to identify the owner/operator before it can
provide them with the notification, reducing the ability of the EPA to
provide timely notification of these events to the owner/operator.
Additional Super Emitter Program implementation issues have impacted
the overall anticipated effectiveness of the program. For example, the
Agency expected that the program would generate sufficient interest
from multiple third-party notifiers and that data collected using the
EPA-approved remote sensing technologies (e.g., satellites) would lead
to expeditious and effective mitigation of super-emitter events by
owners and operators. As stated in the March 2024 Final Rule, in
response to comments, the EPA emphasized that the Super Emitter Program
would only authorize third parties to use remote sensing technologies,
not technologies that would require close access to such facilities.
The EPA specifically identified satellites and aircraft as technologies
that would play a fundamental role in the ATM program. At the time of
the March 2024 Final Rule publication, several satellites capable of
detecting methane were already in operation and additional satellites,
including commercial and non-profit satellites were anticipated to be
launched. The Agency expected that the availability of these systems
would contribute to providing the broad coverage essential to the
effectiveness of the ATM program as a compliance assurance tool. The
EPA anticipated that the participation of third parties with a range of
remote sensing technologies would strengthen the ATM program's ability
to identify large emission events and thereby support compliance with
NSPS OOOO, OOOOa, OOOOb and the EG OOOOc presumptive standards.
However, the EPA only received three technology applications from
remote sensing companies for use in the Super Emitter Program, since
the program began accepting applications in March 2024.\96\
Additionally only one entity has requested and become a certified third
party under the Super Emitter Program.\97\ With only one third party
certified and no other entities requesting third party certification,
the Program is not expected to achieve the coverage originally
envisioned and thus, would not function as the effective compliance
assurance tool.
---------------------------------------------------------------------------

\96\ Third-Party Certifications. <a href="https://www.epa.gov/emc/third-party-certifications">https://www.epa.gov/emc/third-party-certifications</a>.
\97\ <a href="https://www.epa.gov/system/files/documents/2025-01-matm001-carbon-mapper-aerial-survey.pdf">https://www.epa.gov/system/files/documents/2025-01-matm001-carbon-mapper-aerial-survey.pdf</a>.
---------------------------------------------------------------------------

In addition, with respect to the program's scope, the EPA notes
that the Super Emitter Program, as designed, is overly broad, mostly
capturing permissible events where no action is required or other
short-term events that have already been resolved and thus, would not
be effective in addressing events the Agency previously feared would
not be adequately captured or addressed by other requirements. In the
March 2024 Final Rule, the EPA finalized requirements that the
notification must be supplied to the EPA within 15 days after the
detection event in order to provide actionable information to owners or
operators.\98\ However, early program implementation experience
demonstrated that, in most cases where the EPA issued a notification
under the Super Emitter Program (six out of seven total notifications
sent), the owner or operator received the notification after the event
had ended. This aligns with a recent study, which indicates that most
super-emitter events persist only for short periods, typically on the
scale of hours, and are often attributable to routine process or
maintenance events.\99\ Given the inherent lag between the occurrence
of a large emission event, the detection and attribution process, and
the operator's receipt of a notification, many notifications from the
Super Emitter Program would be expected to arrive after the event has
already been resolved. Although at the time of the March 2024 Final
Rule, the EPA understood that many large emission events are
intermittent events,\100\ the Agency now expects that in the majority
of cases, the notifications will pertain to these types of events
instead of focusing on events that the EPA was previously concerned
would not be mitigated by the other provisions in the NSPS OOOO, OOOOa,
OOOOb, OOOOc and the emission guidelines. Additionally, the delay
between event identification and notification, resulting in
notifications that arrive well after the event has ended, can create
additional practical challenges for operators attempting to determine
the cause of the event identified. Based on these factors together with
the minimal third-party participation, the EPA proposes to conclude
that the Super Emitter Program, as designed, is not effective. The
EPA's proposal regarding the program's lack of effectiveness alters the
EPA's understanding of the significance of the burden on owners/
operators due to requirements to respond to notifications about
permissible activities. If the Program cannot reliably distinguish true
super emitter events from permissible releases or routine maintenance
activities, operators may be required to use resources to respond to
notifications for which no corrective

[[Page 68248]]

action is required, such as gas well liquids unloading events.
---------------------------------------------------------------------------

\98\ 89 FR 16920 (March 8, 2024).
\99\ Cusworth, D.H., et al. (2026). Duration of super-emitting
oil and gas methane sources. Published online: January 24, 2026.
Nat. Commun. 2026 Jan 24;17(1):2011. doi: 10.1038/s41467-026-68804-
7. PMID: 41580397; PMCID: PMC12936207. <a href="https://pubmed.ncbi.nlm.nih.gov/41580397/">https://pubmed.ncbi.nlm.nih.gov/41580397/</a>.
\100\ 89 FR 16904, 16920 (March 8, 2024).
---------------------------------------------------------------------------

For these reasons, the EPA proposes to conclude that the Super
Emitter Program is not necessary to retain and does not function
effectively as a compliance assurance tool. To the extent that the
Administrator believes additional information is required to help
assure compliance with, or identify potential violations of,
requirements under the CAA and its implementing regulations, or
otherwise seeks to obtain additional information on super-emitter
events, the EPA may rely on other information collection or compliance
assurance tools, such as CAA section 114 information collection
requests under the authority expressly provided under the CAA. Further,
anyone who wishes to submit information to the EPA about methane
releases remains free to do so, even without the mechanism of the Super
Emitter Program.
The EPA further proposes, as a separate potential basis for repeal,
that portions of the Super Emitter Program lack an adequate legal basis
under the CAA. At the very least, the EPA did not fully articulate a
clear legal basis for all portions of the program in the March 2024
Final Rule. The EPA explained its legal authority for establishing the
program in this way:

[T]he EPA's authority to require sources (regardless of whether
those sources are regulated under CAA section 111) to investigate
potential sources of super-emitter events and report to the EPA is
CAA section 114. The EPA's authority to require regulated sources to
repair or otherwise address the cause of the super-emitter event is
CAA section 111. In particular, for sources regulated under CAA
section 111, the Super Emitter Program will serve as: (1) an
additional work practice standard under NSPS OOOOb (and presumptive
standard under EG OOOOc) for fugitive emissions at well sites,
centralized production facilities and compressor stations, and as
(2) an additional compliance assurance measure for other NSPS OOOOb
affected facilities, NSPS OOOO and OOOOa affected facilities, and
designated facilities under EG OOOOc.\101\
---------------------------------------------------------------------------

\101\ 89 FR 16877.

Despite this broad assertion of authority, certain regulatory
provisions at the heart of the program do not appear to be authorized
by either CAA section 111 or 114.
First, CAA section 114 is comprised of a few different, but
interlocking, elements. CAA section 114(a)(1) specifies that the EPA
``may require any person who owns or operates any emission source, who
manufactures emission control equipment or process equipment, who the
Administrator believes may have information necessary for the purposes
set forth in this subsection, or who is subject to any requirement of
this chapter,'' (except for manufacturers subject to certain title II
requirements, who are subject to CAA section 208), to produce and
provide certain information. These are the groups of ``person[s]'' from
whom the EPA can collect information under CAA section 114. Further,
CAA section 302(e) defines ``person'' to include ``an individual,
corporation, partnership, association, State, municipality, political
subdivision of a State, and any agency, department, or instrumentality
of the United States and any officer, agent, or employee thereof.''
Second, CAA section 114 specifies that the EPA may require ``any
person,'' in one of the groups described above, to ``establish and
maintain such records . . . make such reports . . . install, use, and
maintain such monitoring equipment . . . sample such emissions . . .
keep records on control equipment parameters, production variables or
other indirect data when direct monitoring of emissions is impractical
. . . submit compliance certifications . . . and . . . provide such
other information as the Administrator may reasonably require.'' \102\
Third, with respect to the timing, or frequency, of data collection,
CAA section 114(a)(1) specifies that the EPA may require this
information ``on a one-time, periodic or continuous basis.'' And
fourth, CAA section 114(a) specifies that the EPA may collect
information in accordance with the parameters explained above for the
purposes of: (i) developing or assisting in the development of any
implementation plan under CAA sections 110 or 111(d), or any emission
standard under CAA sections 111 or 112 or any regulation under CAA
section 129; (ii) determining if any person is in violation of any such
standard or any requirement of an implementation plan; or (iii)
``carrying out any provision'' of the CAA (with the exception of
certain provisions under title II of the CAA).
---------------------------------------------------------------------------

\102\ 42 U.S.C. 7414(a)(1)(A)-(G).
---------------------------------------------------------------------------

When describing the Super Emitter Program, the first several
``major elements'' of the program that the EPA listed do not appear to
fit within the framework laid out by CAA section 114.\103\ These
elements include (a) qualifications for third-party notifiers, (b)
third-party notifier certification, and (c) notifications of super-
emitter events (which includes a description of self-imposed EPA
regulatory obligations). For purposes of NSPS OOOOb, these elements can
be found in the regulations at 40 CFR 60.5371b(a), (b), and (c),
respectively. As previously noted, the March 2024 Final Rule also
required States to establish comparable programs.
---------------------------------------------------------------------------

\103\ 89 FR 16879-80.
---------------------------------------------------------------------------

While all components of the Super Emitter Program were designed to
work together, the first two elements are closely related. The first
element of the program includes the regulations regarding
qualifications for third-party notifiers, which state that ``[a]n
entity may apply . . . for approval as a third-party notifier.'' \104\
The second element is a lengthy regulatory provision detailing the
certification, and de-certification, process for third-party notifiers,
and states that ``[a]n entity . . . may apply to be certified as a
third-party notifier.'' \105\ Neither of the regulatory provisions for
these program elements appear to fit within the ambit of CAA section
114 because both provisions involve voluntary actions. No entity is
required to become, or apply to become, a certified third-party
notifier. While CAA section 114 allows the EPA to require certain
information from certain entities under certain conditions, it does not
speak to establishing criteria and procedures for the certification,
and de-certification, of entities who might voluntarily choose to
provide information to the EPA. CAA section 114 states that the EPA
``Administrator may require'' certain entities to complete enumerated
tasks and provide certain information, but these provisions do not
require anyone to do anything; they merely list criteria and a process
to become ``certified'' to submit information to the EPA if an entity
so desires. This voluntary certification process is not contemplated by
CAA section 114. As such, these regulations do not appear to fit within
the scope of EPA's authority under CAA section 114. Nor do they appear
to justify requiring States to establish comparable programs. To be
clear, the Super Emitter Program did not change the ability of any
person to submit any information they would like to the EPA at any time
outside the auspices of the program, and no such certification or
particular qualifications are required for such submissions.
---------------------------------------------------------------------------

\104\ 40 CFR 60.5371b(a).
\105\ Id. 60.5371b(b).
---------------------------------------------------------------------------

Further, the record for the March 2024 Final Rule provides no
explanation of how these provisions derive authority from CAA section
114. The closest explanation in the March 2024 Final Rule states that
``[i]t is the EPA's long-standing position that `information will be
considered to have been provided . . . under section 114 of the Act . .
. if its submission could have been

[[Page 68249]]

required under section 114 . . . .' '' \106\ But this statement relates
to whether the EPA could require the submission of information on a
super-emitter event from a third party, not whether CAA section 114
provides authority to establish criteria and processes regarding the
voluntary submission of information.
---------------------------------------------------------------------------

\106\ 89 FR 16916 (quoting 40 CFR 2.301(b)(2)).
---------------------------------------------------------------------------

Likewise, 40 CFR 60.5371b(c) does not appear to fit within EPA's
authority under CAA section 114. Most relevant here, that provision
binds the EPA to take certain actions triggered by the submission of a
notification to the Agency from a certified third party. For example,
it requires that ``[t]he EPA will review the submitted notifications''
and that ``EPA will assign the notification'' a report number.\107\
Similarly, the introductory text in 40 CFR 60.5371b imposes obligations
on the EPA by stating that the agency ``shall'' review notifications
received from certified third parties, assign the notification an
identification number, and post information on an EPA web page. CAA
section 114 does not appear to contemplate EPA authority to promulgate
a regulation or establish procedures that obligate the agency to take
certain steps upon action from parties outside the EPA. Thus, these
provisions appear to be outside the scope of EPA's authority under CAA
section 114.
---------------------------------------------------------------------------

\107\ 40 CFR 60.5371b(c).
---------------------------------------------------------------------------

In addition to CAA section 114, in the March 2024 Final Rule, the
EPA stated that the legal authority for the Super Emitter Program also
derived from CAA section 111 in two respects: as an additional work
practice standard and as an additional compliance assurance measure.
However, the same regulatory provisions discussed above do not appear
to fit within either category under CAA section 111. First, the EPA
stated that it had ``incorporated the Super Emitter Program, in
particular the requirement to repair fugitive emissions components that
are sources of super-emitter events, as a part of the BSER and
therefore work practice standards for fugitive emissions components
affected/designated facilities under NSPS OOOOb/EG OOOOc.'' \108\ The
EPA's discussion of this issue in the March 2024 Final Rule is limited
and does not explicitly take the position that third-party
certification, criteria for certification, or EPA's self-imposed
regulatory obligations are themselves part of the ``best system of
emission reduction'' for an affected source. Put another way, the
regulations at 40 CFR 60.5371b(a)-(c), which establish the process for
certifying third-party notifiers, do not seem to flow from the EPA's
standard-setting authority in CAA section 111 as none of these
processes appear to be part of the ``standard of performance'' as
defined by CAA section 111(a)(1). Again, these processes are all
voluntary in the sense that no entity is required to apply to the EPA
to become a certified third-party notifier, and no certified third
party is required to send the EPA any notifications under the Super
Emitter Program. The March 2024 Final Rule contains no explanation of
how the EPA's standard-setting authority could be the source of
authority for these voluntary processes.
---------------------------------------------------------------------------

\108\ 89 FR 16878 (March 8, 2024).
---------------------------------------------------------------------------

The EPA acknowledges that ``[e]missions from certain fugitive
emissions components can be significant (as one example, a stuck-open
thief hatch) and can remain undetected until the next scheduled
periodic monitoring.'' \109\ However, we now propose to conclude that
the Super Emitter Program is not essential to addressing those
emissions (i.e., it is not necessary to utilize the program as an
additional work practice standard) because there are already mechanisms
in the regulations to address such emissions when they become known to
owners and operators of affected sources. For example, 40 CFR
60.5397b(h) requires the repair of ``each identified source of fugitive
emissions'' regardless of when the source of the fugitive emissions is
identified. In addition, 40 CFR 60.5370b(b) requires that owners and
operators ``[a]t all times . . . maintain and operate any affected
facility including associated air pollution control equipment in a
manner consistent with good air pollution control practice for
minimizing emissions.'' \110\
---------------------------------------------------------------------------

\109\ Id.
\110\ See also 40 CFR 60.11(d).
---------------------------------------------------------------------------

Moreover, CAA section 111 does not provide legal authority to
establish the Super Emitter Program's certification procedures as an
additional compliance assurance measure. In the March 2024 Final Rule,
the EPA asserted that the Super Emitter Program would serve as a
compliance assurance measure for sources that are not fugitive
emissions components affected/designated facilities under NSPS OOOOb/EG
OOOOc. The EPA reasoned that, although design, operational, monitoring,
recordkeeping, and reporting requirements under other applicable
sources of law already obligated such sources to identify and correct
emissions events, super-emitter events ``are unpredictable'' and ``can
occur between routine inspections and release significant emissions in
a short span of time.'' \111\ The EPA then concluded that the Super
Emitter Program could ``serve as an additional source of monitoring
data to inform and alert owners and operators'' to check for compliance
with applicable Federal or State requirements.\112\ However, each
standard within the March 2024 Final Rule already has its own set of
compliance assurance mechanisms to ensure compliance with the
applicable standards. Further, if a source owner or operator becomes
aware that they might be operating out of compliance, it is in their
interest to investigate and take corrective action, if needed. As
previously noted, the processes and criteria for certifying third-party
notifiers do not themselves ensure compliance with any standard, so CAA
section 111 does not appear to provide authority for 40 CFR
60.5371b(a)-(c).
---------------------------------------------------------------------------

\111\ Id.
\112\ Id.
---------------------------------------------------------------------------

Finally, the EPA proposes that the Super Emitter Program was not
contemplated by the citizen-enforcement provision in CAA section 304--
the provision of the statute (in addition to public-participation
requirements) in which Congress addressed the role of citizens in
implementation of the CAA. Notifications submitted by third parties
pursuant to the Super Emitter Program are sent to the EPA in the first
instance, where they undergo an initial EPA review, and are then
transmitted by the EPA to relevant owners and operators. However, the
EPA is concerned that the third-party certification and notification
procedures could improperly elevate certain unaffiliated third parties
over others and confer special status that Congress did not contemplate
in any provision of the CAA. Under CAA section 304, citizens may bring
actions on their own behalf alleging any violation of applicable
standards, including those in NSPS OOOO, OOOOa, OOOOb, or EG OOOOc, to
the extent those standards have been implemented and are federally
enforceable. In authorizing such actions, Congress provided a number of
constraints and guardrails, including a requirement to provide 60-day
advance notice to the EPA prior to commencing a citizen suit and a
venue provision specifying that citizen suits may only be brought in
federal district court.\113\ By nature of being brought in Federal
district court, such matters are subject to generally applicable
evidentiary rules and standards for adjudicating such

[[Page 68250]]

allegations. None of these provisions contemplate endowing particular
entities with the status of certified monitors for purposes of ensuring
compliance, as the Super Emitter Program does. The EPA proposes that
the CAA's provisions for citizen involvement in enforcement are the
appropriate avenue for citizen participation in such matters. The EPA
now believes that third-party certification could have an unintended
influence on enforcement actions, including with respect to a district
court's review of a citizen action brought by a certified third-party.
That is, the EPA is concerned that status as a certified third-party
could inaccurately and improperly suggest that a citizen action has
been endorsed by the Agency, implicitly or otherwise. In this way, the
Super Emitter Program risks empowering unaffiliated third parties to
exercise an enhanced enforcement role that the EPA did not intend to
establish in finalizing the Super Emitter Program and appears to lack a
statutory basis.
---------------------------------------------------------------------------

\113\ See 42 U.S.C. 7604(a)(1), (b), (c).
---------------------------------------------------------------------------

The same reasoning explained above extends to all regulations where
the EPA included provisions from the Super Emitter Program, such as
provisions at 40 CFR 60.5371, 40 CFR 60.5371a, 40 CFR 60.5371b, and 40
CFR 60.5388c.
Accordingly, for the reasons described above, the EPA proposes to
repeal the Super Emitter Program. The Super Emitter Program includes
requirements under NSPS OOOO, OOOOa, OOOOb and EG OOOOc. As such, the
EPA specifically proposes to remove the Super Emitter Program
provisions at 40 CFR 60.5371, 40 CFR 60.5371a, 40 CFR 60.5371b, and 40
CFR 60.5388c. The EPA also proposes to remove references to these
provisions at 40 CFR 60.5398b(d), and 60.5420b(b)(14); and 40 CFR
60.5420c(b)(14); and in the definition of ``[a]verage aggregate
detection threshold'' in 40 CFR 60.5430b and 40 CFR 60.5430c. Lastly,
the EPA proposes to remove reference to the Super Emitter Program in
table 1 to subpart OOOOc of 40 CFR part 60. The EPA solicits comment on
this proposal (Question III.1a), including any comments related to the
policy merits of the Super Emitter Program and to the EPA's legal bases
for the Super Emitter Program.

B. Liquids Unloading

1. Background
Under the March 2024 Final Rule, both the NSPS OOOOb and EG OOOOc
require each affected and designated gas well facility that unloads
liquids to employ techniques (e.g., manual unloading steps taken to
unload liquids) or technology(ies) (e.g., plunger lift systems, surface
jet pumps, velocity strings) that minimize or eliminate venting of
emissions during liquids unloading events. As an alternative, owners or
operators may comply with the GHG and VOC standards by routing vented
emissions to a control device that reduces methane and VOC emissions
(methane only for designated facilities) from each gas well liquids
unloading event by 95.0 percent.
For unloading technologies or techniques that could result in
venting to the atmosphere, the March 2024 Final Rule requires owners or
operators to follow certain work practices. The March 2024 Final Rule
requires that owners or operators employ and document best management
practices to minimize venting of methane and VOC emissions for each gas
well liquids unloading operation. Specifically, owners or operators of
affected and designated gas well facilities that undergo liquids
unloading events must develop, maintain, and follow a best management
practice plan to minimize venting of methane and VOC emissions (methane
only for designated facilities) to the maximum extent possible from
each gas well liquids unloading operation. This best management
practice plan must meet the following minimum criteria: (1) include
steps that create a differential pressure to minimize the need to vent
a well to unload liquids; (2) include steps to reduce wellbore pressure
as much as possible prior to opening the well to the atmosphere; (3)
unload liquids through the separator where feasible; and (4) close all
wellhead vents to the atmosphere and return the well to production as
soon as practicable. The standards are the same for the NSPS and the
EG.
Where liquids unloading events are conducted using a technology or
technique that eliminates venting to the atmosphere, the March 2024
Final Rule requires owners and operators to report the identification
of the well along with the non-venting technology or technique used in
their annual report. If more than one non-venting method is used, the
March 2024 Final Rule requires that owners and operators maintain
records of all the differing non-venting liquids unloading methods used
at the well affected/designated facility.
When unplanned venting occurs from these wells during a compliance
period, an owner or operator is required to follow their best
management practices plan for such events and comply with the
associated recordkeeping and reporting requirements for those events.
The March 2024 Final Rule requires owners and operators to maintain
records for the number of unplanned events where emissions are vented
to the atmosphere during a liquids unloading operation. The March 2024
Final Rule requires owners and operators to provide the above
recordkeeping information to the EPA in their annual report.
2. Additional Background and Summary of Proposed Changes and Rationale
Petitioners raised two issues for reconsideration on the March 2024
Final Rule liquids unloading requirements.114 115 First,
petitioners disagreed with the EPA's promulgated reporting and
recordkeeping requirements for liquids unloading events for non-
emitting equipment or activities. Second, petitioners argued that the
alternative compliance option for GHG and VOC reduction standards--
allowing an owner or operator to route emissions to a control device
via a CVS--imposes inappropriate ongoing compliance assurance
requirements when applied to normally intermittent liquids unloading
activities. Sections III.B.2.a and III.B.2.b of this preamble provide
additional background, a summary of proposed changes, and rationale for
proposed changes for both of these issues.
---------------------------------------------------------------------------

\114\ API & AXPC (2024a). Re: Provisions in EPA's Final Rule
``New Source Performance Standards and Emission Guidelines for Crude
Oil and Natural Gas Facilities: Climate Review.'' Creating Immediate
Compliance and Implementation Issues. April 5, 2024.
\115\ API & AXPC (2024b). Re: Request for Administrative
Reconsideration of EPA's Final Rule ``New Source Performance
Standards and Emission Guidelines for Crude Oil and Natural Gas
Facilities: Climate Review'' May 6, 2024. pgs. 33-34.
---------------------------------------------------------------------------

a. Recordkeeping and Reporting Requirements for Non-Emitting Operations
Background. Petitioners asserted that the presence of emissions is
inherent in the definition of standard of performance and that a source
without emissions cannot be subject to such a standard of
performance.\116\ Petitioners also stated that the EPA itself
recognized its inability to regulate these non-venting events when it
``streamlined recordkeeping and reporting requirements'' based on
concerns raised during the comment period for the March 2024 Final
Rule.\117\ Specifically, the petitioner quoted the EPA's Response to
Comments for the

[[Page 68251]]

March 2024 Final Rule as stating that the Agency agreed that
``requiring an owner or operator to comply with some of the proposed
recordkeeping and reporting requirements in instances where an
unloading event does not result in venting to the atmosphere would
impose a burden without any added benefit environmentally . . . ''
\118\ Petitioners argued that based on these reasons, the EPA should
remove all recordkeeping and reporting requirements associated with
non-venting activities and equipment.
---------------------------------------------------------------------------

\116\ API & AXPC (2024b). Re: Request for Administrative
Reconsideration of EPA's Final Rule ``New Source Performance
Standards and Emission Guidelines for Crude Oil and Natural Gas
Facilities: Climate Review'' May 6, 2024. pgs. 33-34.
\117\ 89 FR 16956 (March 8, 2024).
\118\ U.S. EPA. (2023b). Standards of Performance for New,
Reconstructed, and Modified Sources and Emissions Guidelines for
Existing Sources: Oil and Natural Gas Sector Climate Review.
Response to Public Comments on the November 2021 Proposed Rule and
the December 2022 Supplemental Proposed Rule. See Response I-12-33.
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Summary of Proposed Changes and Rationale. In promulgating the
March 2024 Final Rule, the EPA considered commenters' concerns and the
examples provided regarding the burden associated with the liquids
unloading operations' recordkeeping and reporting requirements proposed
in 2022. In the March 2024 Final Rule, the EPA streamlined
recordkeeping and reporting requirements in some instances where an
unloading event does not result in venting to the atmosphere and where
such requirements would impose a burden without providing any
environmental benefit (e.g., requiring operators to track and report
the number of liquids unloading events that occurred when implementing
a non-venting liquids unloading technology or technique). Where liquids
unloading events are conducted using a technology/technique that
eliminates venting to the atmosphere, the March 2024 Final Rule
requires owners and operators to report the identification of the well
along with the non-venting technology or technique used in their annual
report, while continuing to comply with the applicable recordkeeping
requirements for those events. Where unplanned venting occurs from
these wells during a compliance period, an owner or operator is
required to follow their best management practices plan for such events
and comply with the associated recordkeeping and reporting requirements
for those events.
The EPA proposes to further eliminate the reporting requirements
for non-venting liquids unloading well site events, while maintaining
the recordkeeping requirements for these events in both the NSPS OOOOb
and EG OOOOc due to the continued possibility of an unplanned venting
event. The EPA proposes changes to 40 CFR 60.5376b(a)(1) and
60.5420b(c)(2)(i) of NSPS OOOOb, and 40 CFR 60.5390c(a)(1) and
60.5420c(c)(1)(i) of EG OOOOc. Specifically, the EPA proposes that the
NSPS OOOOb and EG OOOOc continue to require that owners and operators
maintain records of the identification of each well (i.e., U.S. Well ID
or U.S. Well ID associated with the well affected facility) that
conducts a gas well liquids unloading operation during the reporting
period without venting of methane and/or VOC emissions and the non-
venting gas well liquids unloading method used. These records, which
EPA understands would already be retained as part of normal site
operations records/documentation, do not constitute a burdensome
requirement. The EPA solicits comment on this proposal. (Question
III.2a)
The EPA is also soliciting comment on repealing part or all of the
recordkeeping and reporting requirements for liquids unloading in NSPS
OOOOb, and the corresponding presumptive requirements in EG OOOOc. The
Agency's ICR associated with the March 2024 Final Rule anticipated that
the recordkeeping and reporting burdens associated with liquids
unloading would increase significantly over the first three years of
implementation. The EPA seeks comment on whether those projected costs
have materialized, and if so, which provisions are the most burdensome
and whether the costs may warrant further revisions in relation to the
purposes of the requirements. (Question III.2b)
b. Control Device Compliance Requirements
Background. Petitioners stated that while they generally support
the work practice procedures finalized in 40 CFR 60.5376b, they do not
support the covers, closed vent and control device compliance assurance
requirements at 40 CFR 60.5376b(g), which are associated with the
alternative compliance option of routing vented emissions to a control
device.\119\ While the petitioners do not oppose including the
alternative compliance option, they assert that the associated ongoing
compliance assurance requirements are inappropriate. They explain that,
when implementing the work practice procedures to reduce emissions from
well liquid unloading activities as specified in 40 CFR 60.5376b(b)
through (f), operators will review the characteristics of the well at
the time of the event. If certain conditions (e.g., operator safety,
equipment malfunctions) are present, an operator may need to deviate
from a planned option for minimizing emissions and instead route gas to
a temporary flare to minimize emissions and further reduce the amount
of gas that would be vented by 95.0 percent. Petitioners noted that,
given the short-term nature of liquids unloading events, the ongoing
compliance assurance related to both a CVS and control device would be
inappropriate since many of the activities would be forced to occur
when liquids unloading activities are not even occurring (e.g., CVS
inspections). They contended that it would also be untenable to
schedule and manage these activities during unloading events given
their variable and short duration. Petitioners recommended that the EPA
authorize the use of a temporary flare or portable control device to
handle emissions from liquids unloading. Specifically, they suggested
that, due to the temporary nature of these activities, the control
device compliance requirements should mimic those utilized for well
completions affected facilities, i.e., a requirement to operate with a
reliable continuous pilot flame during the liquid unloading activity.
Petitioners noted that a temporary control device is typically used
when the permanent control device is down for maintenance (e.g., during
a gas plant turnaround) or to reduce emissions from intermittent
activities (e.g., liquids unloading where feasible). In general, the
petitioners stated that the March 2024 Final Rule does not specifically
address temporary control devices, and as such, temporary control
devices would presumably have to meet what they argue are untenable
monitoring and performance testing requirements required under the rule
for these control devices. Therefore, the petitioners urged the EPA to
revise the March 2024 Final Rule to clearly exempt temporary control
devices from the monitoring and performance testing requirements
required under the rule for these control devices.
---------------------------------------------------------------------------

\119\ API & AXPC. (2024a).
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Summary of Proposed Changes and Rationale. For liquids unloading
operations, the initial and supplemental proposals for the March 2024
Final Rule did not include an option to route emissions to a flare/
control device. The March 2024 Final Rule introduced an additional
means of complying with the GHG and VOC standards by reducing methane
and VOC emissions from each gas well liquids unloading event by 95.0
percent by routing emissions to a control device via a CVS. This option
was added in response to comments requesting that routing to a control
device be allowed, noting that the

[[Page 68252]]

emissions reduction that would be achieved could be greater than or
equal to those achieved through the implementation of best management
practices (BMPs). The EPA acknowledges the practical implications of
requiring the same control device compliance assurance requirements
that were developed for control devices where emissions are routed to a
permanent control device to also apply where emissions are routed to a
temporary control device. For the same reasons specified by the
petitioners, the EPA proposes to determine that it is warranted to
develop different control device and compliance provisions that
acknowledge the differences between permanent and temporary control
devices. As such, the EPA proposes to allow routing of vented gas to a
temporary control device during liquids unloading operations with
streamlined compliance assurance requirements. See section III.H.1.e
(Temporary Control Devices and Backup Control Devices) of this preamble
for a detailed discussion on the EPA's proposed compliance provisions
for temporary control devices for use during intermittent liquids
unloading events.

C. Process Controllers

1. Background
Under the March 2024 Final Rule, the NSPS OOOOb final standards and
EG OOOOc final presumptive standards contain requirements for each
process controller affected or designated facility. These rules define
process controller affected and designated facilities as the collection
of natural gas-driven process controllers at a well site, centralized
production facility, onshore natural gas processing plant, or a
compressor station. The definitions of affected and designated
facilities exclude natural gas-driven process controllers that function
exclusively as emergency shutdown devices as well as process
controllers not driven by natural gas, so neither the NSPS nor the EG
applies to these types of controllers. The NSPS standards and the EG
presumptive standards require process controller affected or designated
facilities to have zero methane and VOC emissions to the atmosphere,
except for affected or designated process controllers located in Alaska
at a site without electrical power. For process controller affected or
designated facilities located at Alaska sites that do not have access
to electrical power, an owner or operator may either route process
controller emissions through a CVS to a control device that reduces
emissions by 95.0 percent, or they may use intermittent vent or low-
bleed process controllers (i.e., those that have a bleed rate less than
or equal to 6 standard cubic feet per hour (scfh)) so long as they
perform periodic monitoring of their intermittent controllers to ensure
those controllers are not emitting to the atmosphere during idle
periods.
To address concerns about new sources' ability to obtain the
equipment necessary to demonstrate compliance with the final standard
of zero emissions immediately upon the effective date of the final
rule, the March 2024 Final Rule NSPS allowed up to 1 year from the
effective date of the final rule (i.e., May 7, 2025) to come into full
compliance with the final NSPS standard of zero emissions. Until that
date of compliance, owners and operators must demonstrate compliance
with an interim standard which mirrored the requirements for sites in
Alaska that do not have access to electrical power.\120\ To address
continuing concerns about the supply chain and the ability of new
sources to obtain the necessary equipment to comply with the process
controller requirements by May 7, 2025, the EPA issued an IFR and
request for comment on July 31, 2025 to revise the compliance date for
the zero emissions standards.\121\ The EPA then responded to comments
on the IFR and issued a final rule.\122\ The NSPS compliance date for
the zero emissions standard for process controllers is now January 22,
2027, and the interim standard continues to apply to process controller
affected facilities (i.e., the same standard applicable to sites in
Alaska without access to electricity) until that date.\123\
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\120\ 89 FR 16929, 16930 (March 8, 2024).
\121\ 90 FR 35966 (July 31, 2025).
\122\ The December 2025 Final Rule responded to the comments and
reaffirmed the conclusions and the regulatory amendments made in the
July 2025 IFR. 90 FR 55671 (December 3, 2025).
\123\ 90 FR 35973, 35974 (July 31, 2025).
---------------------------------------------------------------------------

For EG OOOOc, which included presumptive standards for process
controllers, the March 2024 Final Rule included a State plan submittal
deadline of 24 months after publication of the final EG OOOOc (i.e.,
March 9, 2026). To provide more time for States to develop their State
plans, the July 2025 IFR extended the State plan submittal deadline to
January 22, 2027. See section II.E of this preamble for additional
details regarding the IFR.
Reconsideration petitioners raised several issues regarding the
March 2024 Final Rule process controller requirements that they
requested the EPA reconsider. One issue regards cost effectiveness of
the presumptive standard for some applications, with petitioners
asserting that the zero emissions standard is not cost effective for
existing process controllers used in high-pressure systems at
transmission and storage compressor stations. Another issue regards the
definition of modification for process controllers, for which
petitioners assert that the EPA should clarify that a modification of
affected or designated process controller facilities only occurs when
there is both an increase in emissions and one or more process
controllers is added to the affected or designated facility. Sections
III.C.2.a and III.C.2.b of this preamble provide additional background,
a summary of proposed changes, and the rationale for the proposed
changes. Petitioners also raised issues regarding process controllers
at marginal well sites and process controllers on temporary equipment.
Finally, petitioners also raised concerns regarding reporting burdens
centered around process controller monitoring and recordkeeping.
Sections III.K.1.f and III.H.1.e of this preamble address these issues.
2. Additional Background and Summary of Proposed Changes and Rationale
a. Process Controllers on High-Pressure Systems at Transmission and
Storage Compressor Stations
Background. Petitioners provided information regarding the cost of
process controllers used in high-pressure systems at transmission
compressor stations, which shows that the retrofit cost for existing
facilities to come into compliance with the zero-emissions process
controller standard for high-pressure systems is over 400 times higher
than that analyzed by the EPA for the March 2024 Final Rule.\124\ EPA
estimated a single-pollutant cost effectiveness value of $1,924/ton of
methane for retrofitting an existing facility with compressed air in
the Small Transmission and Storage Model Plant analysis in the March
2024 Final Rule.\125\ For comparison, three companies estimated a cost
effectiveness of $860,714, $2,887,686, and $3,417,977 per ton of
methane reduced, respectively, to replace valve actuators at existing
high pressure transmission and storage stations they

[[Page 68253]]

were operating.\126\ Petitioners explained that the amount of
compressed air needed to actuate high-pressure process controllers,
which the petitioners characterized as requiring a pressure of 100
pounds per square inch gauge (psig) or greater, requires more expensive
process controller equipment and facility infrastructure than that
included in the EPA's BSER analysis for the March 2024 Final Rule.
Petitioners noted that the EPA's analysis focused on upstream
processes, data, and equipment, and these elements are not the same for
many process controller applications in the transmission and storage
segment. Petitioners asserted that the replacement of the process
controllers, and in particular, the valve actuators that would be
required to meet the zero emissions standard for these high-pressure
applications is much more expensive than that included in the EPA's
analysis for the cost of replacing process controllers. Petitioners
also stated that due to reliability and safety concerns, the conversion
of these process controllers and their actuators would be to instrument
air-powered devices rather than electrically-powered or self-contained
devices. Petitioners noted that this is because pneumatic actuators are
typically faster than electric alternatives, which is essential for
quick process adjustments at the compressor.
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\124\ Interstate Natural Gas Association of America (INGAA).
(2024a). Petition. Letter to Michael S. Regan from INGAA. Re:
Petition for Reconsideration of Final Rule or, in the Alternative,
for New Rulemaking in ``Standards of Performance for New,
Reconstructed, and Modified Sources and Emissions Guidelines for
Existing Sources: for Reconsideration. (Non-Confidential Version).
May 15, 2024.
\125\ 89 FR 16820 (March 8, 2024).
\126\ Interstate Natural Gas Association of America (INGAA).
(2024a). Petition. Letter to Michael S. Regan from INGAA. Re:
Petition for Reconsideration of Final Rule or, in the Alternative,
for New Rulemaking in ``Standards of Performance for New,
Reconstructed, and Modified Sources and Emissions Guidelines for
Existing Sources: for Reconsideration. (Non-Confidential Version).
May 15, 2024.
---------------------------------------------------------------------------

Petitioners provided data from three companies estimating the cost
effectiveness of replacing natural gas-powered process controllers and
actuators with compressed air-powered process controllers and actuators
at facilities that have electricity at the site. These values ranged
from $860,714 to $3,417,977 per ton of methane emissions reduced, which
are 440 and 1,750 times higher than the EPA's estimate for the March
2024 Final Rule of $1,951 per ton of methane reduced from large
transmission and storage facilities that have electricity at the
site.\127\ Based on these estimates, petitioners argue it is not cost
effective to replace existing natural gas-powered process controllers
and actuators in these high pressure applications with compressed air-
powered process controllers and actuators.
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\127\ INGAA (2024a).
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Summary of Proposed Changes and Rationale. The EPA proposes to
amend the standards for modified and reconstructed facilities under
NSPS OOOOb and the presumptive standards in the EG OOOOc model rule for
process controllers at compressor stations, as defined in 40 CFR
60.5430b and 40 CFR 60.5430c that require an actuation pressure greater
than 100 psig. Like other process controllers, natural gas-driven
process controllers at natural gas compressor stations that require an
actuation pressure greater than 100 psig and that function exclusively
as emergency shutdown devices are not included in the affected or
designated facility. This is also true for controllers not driven by
natural gas. Put another way, the revisions that the EPA is proposing
here do not impact the regulatory exclusion for emergency shutdown
devices and for controllers not driven by natural gas. The EPA proposes
to create a new subcategory which includes new NSPS requirements (for
modified and reconstructed sources), and new presumptive standards, for
these high-pressure process controllers, which are based on the revised
BSER analysis and on the conclusion that retrofitting to zero-emissions
controllers is not technically feasible or cost effective. Under the
proposed requirements, an owner or operator may either route process
controller emissions through a CVS to a control device that reduces
emissions by 95.0 percent, or they may use low-bleed natural gas-
powered process controllers (i.e., those that have a natural gas bleed
rate less than or equal to 6 scfh) in combination with intermittent
vent process controllers so long as the owner/operator periodically
monitors the intermittent controllers to ensure they are not emitting
to the atmosphere during idle periods.
The EPA considered the petitioners' concerns and the information
provided regarding the costs and emission reductions associated with
the process controller requirements at facilities with process
controllers that are on high-pressure systems at transmission
compressor stations. The EPA evaluated the data provided by the
petitioners and contacted vendors regarding the costs of process
controllers and actuators for high-pressure systems at these sites. The
EPA agrees that the equipment costs are higher than those considered in
the 2024 BSER analysis, as the Agency did not have sufficient
information available at that time to anticipate the need for different
process controller equipment for high-pressure systems at transmission
compressor stations. The EPA revised the analysis performed for the
March 2024 Final Rule on cost effectiveness of zero-emitting process
controllers for existing, modified and reconstructed sources to include
the new information for process controllers on high pressure systems at
transmission compressor stations.\128\ The nature of these high
pressure systems limits the technical feasibility of routing emissions
from these controllers to a process, control, or sales line and also
limits the use of self-contained process controllers. These facilities
need to use fast-acting process controllers and actuators. Electric
process controllers are not fast enough. Controllers driven by
compressed air are fast enough; they are technically feasible, but
their costs are very high. The EPA evaluated the costs and emissions
reductions of replacing natural gas-powered process controllers with
process controllers driven by compressed air. The EPA estimates that to
replace natural gas-driven process controllers on high pressure systems
with process controllers driven by compressed air at compressor
stations, the capital costs would be $2.4 million, annualized capital
costs would be $263,300, and emissions would be reduced by 0.2 tons per
year (tpy) of VOC and 8.0 tpy of methane, resulting in a cost of $10.9
million per ton of VOC emissions reduced and $33,100 per ton of methane
emissions reduced.\129\ The EPA proposes to determine that these
updated values are not cost effective. Based on this determination,
along with the knowledge that only this subset of controllers faces
these higher equipment and operating costs, the EPA proposes to
determine that a different standard (and presumptive standard) for
process controllers on high pressure systems would be warranted (a
standard other than the zero emission standard) and evaluated other
emissions control options. These options are explained below.
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\128\ Technical Memorandum to Docket ID EPA-HQ-OAR-2021-0317.
Revised Analysis for Process Controllers and Pumps for
Reconsideration of New Source Performance Standards 40 CFR 60,
Subpart OOOOb and Emissions Guidelines 40 CFR 60, Subpart OOOOc.
August 28, 2026.
\129\ This and additional information regarding the revised
analysis conducted for process controllers may be found in the TSD
for this proposal, which is available in the docket for this action.
---------------------------------------------------------------------------

The EPA evaluated the use of alternative control options to zero-
emitting process controllers in NSPS OOOOb and EG OOOOc. The only
emissions control option identified as technologically feasible and
cost effective was the requirement in the NSPS OOOOb and EG OOOOc for
sites

[[Page 68254]]

in Alaska that do not have access to electrical power. To evaluate the
costs of this option for process controllers on high-pressure systems
at transmission compressor stations, the EPA assumed that sites would
choose to use low-bleed or intermittent. Consistent with the
distribution of controller types documented in the March 2024 Final
Rule, where the Agency determined that intermittent-vent controllers
represent the predominant controller type in the field (as reflected in
the one-to-three ratio of low bleed to intermittent vent used in the
model plant analysis), it was assumed that all controllers were of the
intermittent type, and that the process controllers would be monitored
quarterly with OGI to ensure they are operating properly.\130\ The EPA
estimates that annual costs associated with this option would be $300,
and emissions would be reduced by 0.15 tpy of VOC and 5.4 tpy of
methane, resulting in a cost of $2,000 per ton of VOC emissions reduced
and $55 per ton of methane emissions reduced from a representative
affected facility (i.e., transmission compressor station). The EPA
proposes to determine that these values are cost effective and proposes
these requirements (and this presumptive standard) for process
controllers on high pressure systems at compressor stations for
modified and reconstructed facilities under NSPS OOOOb and for the
presumptive standards in the EG OOOOc model rule. The EPA solicits
comment on this proposal. (Question III.3a)
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\130\ 89 FR 16924.
---------------------------------------------------------------------------

Based on the information provided by petitioners, it is the EPA's
understanding that only the retrofit costs for existing sources to come
into compliance with a zero emissions standard are prohibitive. It is
the EPA's understanding that when new facilities are being planned and
constructed, it is possible for zero emissions process controllers to
be incorporated into the facility design at a cost that is similar to
the cost of including natural gas-driven process controllers, such that
it is cost effective to include zero-emissions process controllers on
high pressure systems at natural gas compressor stations. However, if
these facilities were built with process controllers that use natural
gas and are then required to replace those process controllers with
zero emitting equipment, essentially doubling the cost of this already
expensive equipment, it could be cost prohibitive and therefore
unreasonable considering the relatively small amount of emissions
reduction that would be achieved.
Accordingly, the EPA is proposing a different standard only for
existing sources that would be required to retrofit equipment to comply
with the NSPS OOOOb standards (i.e., modified and reconstructed
facilities) and the EG OOOOc presumptive standards but is not proposing
an alternative or different standard for newly constructed facilities
(i.e., for sources subject to NSPS OOOOb that were not previously
existing sources that then modified or reconstructed). Based on the
above understanding, the EPA does not believe that this proposed change
would allow, or result in, new facilities that are planned and
constructed with zero emissions process controllers to revert to
natural-gas driven process controllers. As a function of permitting and
cost, the Agency does not believe that new facilities designed with
zero emissions process controllers would have the incentive or ability
to make such a change by modifying or retrofitting, nor is that result
intended by this proposed change. The EPA is soliciting comment on this
aspect of the proposal, including whether additional or alternative
standards or subcategories for sources subject to NSPS OOOOb are
merited and whether the EPA's premise regarding cost equivalency in the
design and initial planning phases is accurate. (Question III.3b)
The EPA is also soliciting comment on the actuation pressure which
best categorizes these high-pressure systems and whether additional
subcategories are merited. Industry representatives have suggested
using 100 psig as a general guideline for the level of pressure at
which different types of process controllers, and actuators in
particular, become more costly than the equipment needed for lower
pressure levels. However, the EPA is interested in any information that
may suggest that another or additional pressure levels would be better
suited to delineate the subcategory or further subcategories. (Question
III.3c)
b. Modification Criteria for Process Controllers
Background. Petitioners requested that the EPA clarify that a
modification for process controllers occurs only when there is both an
increase in emissions and one or more controllers are added to the
facility. Petitioners recounted that the EPA changed the definition of
affected facility for process controllers from a single process
controller to the collection of all the process controllers at a well
site in NSPS OOOOb. Petitioners also recounted that in NSPS OOOOb, the
EPA changed the modification criteria to state, ``[f]or the purposes of
Sec. 60.5390b, in addition to the definition in Sec. 60.14, a
modification occurs when the number of natural gas-driven process
controllers in the affected facility is increased by one or more.''
According to the petitioners, the regulatory language seems to indicate
that process controllers would be considered modified only if there is
an increase in emissions and the number of natural gas-driven process
controllers is increased by one or more, but in the March 2024 Final
Rule preamble, the EPA focused only on the number of increased
controllers, implying that an increase in process controllers
automatically increases emissions from the affected facility. According
to the petitioners, there are many actions that can take place at the
time a new controller is added to offset its emissions, such as when a
new controller replaces an existing controller with the same or with
higher emissions or when new controller emissions are offset by the
removal of other controllers or adjustments in their operations. The
petitioner reported that these concepts have long been a part of
facility operations management to limit the need for additional
permitting.
Summary of Comment Solicitation. The EPA acknowledges the
petitioners' request for clarification and is soliciting comment on
whether revisions to the current modification determination language in
40 CFR 60.5365b(d)(1) for process controllers are warranted. The EPA
maintains that increasing the total number of natural gas-driven
process controllers at a facility generally increases the emissions of
natural gas, methane, and VOC to the atmosphere by the nature of the
equipment, which bleeds gas continuously and/or emits gas during
actuation events, emits gas during malfunctions of the equipment, or
emits gas through leaks in the equipment or from connections to CVSs.
Adding one more natural gas-emitting process controller to an existing
set of natural gas-emitting process controllers is therefore generally
expected to result in increased emissions. The intent and purpose of
this provision was to simplify modification determinations by
eliminating the need for owners/operators to determine emissions before
and after a change in a process controller affected facility and to
reduce the burden on permitting authorities reviewing that modification
determination. That said, the EPA also recognizes that by statute, an
increase in emissions is a necessary condition to a modification
determination. The EPA also notes that the number of process
controllers in the affected facility does

[[Page 68255]]

not increase when a new natural gas-driven process controller replaces
an existing one, or when the addition of a process controller is offset
by the removal of one or more existing process controllers. The
petitioner suggests that, in some cases, operational adjustments to
other controllers could offset the emissions of the new controller. The
EPA is soliciting additional information on the relative change in
emissions when these process controller replacement events occur and
the frequency with which they occur. The EPA also requests comment on
whether the existing modification determination language appropriately
captures changes resulting in emissions increases, or whether
adjustments to the current criteria are needed to reflect industry
practices, such as clarifying what constitutes net increases in
emissions from the source. (Question III.3d)
The EPA recognizes that other issues raised in reconsideration
petitions \131\ on the March 2024 Final Rule related to process
controllers affected and designated facilities are of interest to
stakeholders. The EPA is still evaluating some of those other issues.
One of those issues, for example, suggests that the EPA reevaluate the
cost-effectiveness of process controllers, especially for existing
source retrofits and consider alternative options for compliance.
Petitioners specifically suggest that the EPA consider for both NSPS
OOOOb and EG OOOOc that routing emissions from process controllers to a
control device should be allowed as an option for compliance.
Furthermore, petitioners suggest that the EPA consider further
subcategorization for existing sites that do not have access to
electricity or have a de minimis number of process controllers.
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\131\ API (2025). Re: Request for Administrative Reconsideration
of EPA's Final Rule ``New Source Performance Standards and Emission
Guidelines for Crude Oil and Natural Gas Facilities''--NSPS OOOObc.
September 12, 2025.
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The EPA is soliciting comment from stakeholders and the public on
these and other specific issues related to process controller affected
and designated facilities. Specifically, the EPA solicits comment on
whether it would be appropriate to consider broader flexibility for
process controllers as the petitioners suggest. The EPA asks for
additional information and data related to cost and technical
feasibility of retrofits, routing to new or existing control devices,
and challenges related to electricity access. The EPA also requests
comment on recordkeeping, retention, and reporting requirements related
to process controllers and whether it is appropriate to repeal the zero
emission standard for process controllers under NSPS OOOOb and EG OOOOc
based on information suggesting that the Agency's prior cost and
emission-reduction projections were erroneous as relevant to the BSER
determinations and resulting standards for such requirements. (Question
III.3e)

D. Pumps

1. Background
Under the March 2024 Final Rule, the NSPS OOOOb final standards and
EG OOOOc final presumptive standards contain requirements for each pump
affected or designated facility, which is the collection of natural
gas-driven pumps at a well site, centralized production facility,
onshore natural gas processing plant, or compressor station. Pumps that
are in operation less than 90 days per calendar year or that are not
natural gas-driven are not included in the definition of affected or
designated facility. For pump affected or designated facilities located
at a site that has access to electrical power and for those without
access to electrical power that have three or more natural gas-driven
diaphragm pumps, the pump affected facility must have zero methane and
VOC emissions to the atmosphere. For each pump affected or designated
facility located at a site that does not have access to electrical
power and that also has fewer than three natural gas-driven diaphragm
pumps, emissions must be controlled if a control device is otherwise
onsite.
Section III.D.2 of this preamble provides additional background,
summary of proposed changes, and rationale for proposed changes.
2. Additional Background and Summary of Proposed Changes and Rationale
Background. Petitioners asserted that the EPA failed to justify
NSPS OOOOb standards and EG OOOOc presumptive standards of zero
emissions for existing natural gas-driven pumps that are already in
compliance with NSPS OOOOa, which requires certain natural gas-driven
diaphragm pumps to be routed to a control device or process that
achieves an emissions reduction of at least 95.0 percent.\132\
Petitioners requested that the EPA's model rule and presumptive
standards in EG OOOOc and the standards in OOOOb (for modified and
reconstructed facilities) allow these existing pumps that are already
reducing emissions by 95 percent to continue to comply with NSPS OOOOa
instead of having to convert to the zero emissions standard (100
percent control as opposed to 95 percent control). Petitioners implied
that the EPA did not adequately consider the incremental cost
effectiveness of requiring existing diaphragm pumps subject to NSPS
OOOOa (and already achieving 95 percent control) to achieve zero
emissions.
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\132\ API-AXPC (2024b).
---------------------------------------------------------------------------

Summary of Proposed Changes and Rationale. The EPA proposes to
amend the standards for modified and reconstructed sources under NSPS
OOOOb and the presumptive standards in the EG OOOOc model rule for
pumps. The proposed amendments include an alternative emissions
standard of 95.0 percent control for individual pumps within a pump
designated (or affected) facility that were already routing emissions
through a CVS to a control device achieving 95.0 percent or greater
control of emissions on the effective date of the March 2024 Final Rule
(i.e., December 6, 2022). These pumps that are already reducing their
emissions by at least 95 percent would not be required to achieve zero
emissions (100 percent reduction of emissions), where zero-emitting
pumps would be the otherwise applicable standard (i.e., sites with
access to electricity or sites without access to electricity that have
three or more diaphragm pumps). The modified/reconstructed standards
under NSPS OOOOb and the presumptive standards under EG OOOOc for any
other pumps in the pump designated facility (meaning those whose
emissions were not already reduced by 95.0 percent) would remain those
finalized in the March 2024 Final Rule. This proposed alternative
standard would apply to any pumps at an affected pump facility or
designated facility that were already routing emissions through a CVS
to a control device achieving 95.0 percent or greater control of
emissions on the effective date of the March 2024 Final Rule,
regardless of whether or not those pumps were previously required by
NSPS OOOOa to achieve 95.0 percent emissions reductions.
The EPA considered the petitioner's concerns and evaluated the
incremental cost effectiveness of moving from 95.0 percent emissions
control to zero emissions (i.e., 100 percent emissions control). For
sites that have access to power from the electrical grid, the options
for achieving zero emissions that were included in this analysis were
the use of a compressed air system to power existing pneumatic pumps
and the replacement of existing natural gas-powered pneumatic pumps
with electrical pumps. For sites that do not have access to power from
the electrical

[[Page 68256]]

grid, the analysis included the option to replace existing natural gas-
powered pneumatic pumps with electrical pumps powered by on-site solar
panels. These options were the most cost effective means of achieving
zero emissions that were analyzed for the March 2024 Final Rule. In the
analysis, the EPA evaluated the difference in costs and the difference
in emissions between the 95.0 percent emissions control scenario and
the 100 percent emissions control scenario. As the systems required for
95.0 percent emissions control already exist and operate, and there is
no overlap in equipment used between these systems and the systems that
would be used for the zero emissions options analyzed, the EPA assumed
that the difference in costs equate to the full costs of the zero
emissions system. The difference in emissions would be 5 percent of the
total emissions (i.e., the difference between 95.0 percent and 100
percent control). A summary of the results of this analysis is shown in
table 3. The cost effectiveness values shown in table 3 are based on
the estimated total annual costs of each zero-emissions pump option and
the emissions reductions associated with going from 95.0 percent to 100
percent emissions control. Further information regarding the analysis
conducted for pumps may be found in a technical memorandum, available
in the docket for this proposed rule.\133\
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\133\ Technical Memorandum to Docket ID EPA-HQ-OAR-2021-0317.
Revised Analysis for Process Controllers and Pumps for
Reconsideration of New Source Performance Standards 40 CFR 60,
Subpart OOOOb and Emissions Guidelines 40 CFR 60, Subpart OOOOc.
August 28, 2026.
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BILLING CODE 6560-50-P

[[Page 68257]]

[GRAPHIC] [TIFF OMITTED] TP29OC26.008

BILLING CODE 6560-50-C
As seen in table 3, the estimated incremental cost effectiveness to
achieve 100 percent emissions control for both VOC and methane are
above the values considered to be reasonable by the EPA. Specifically,
the lowest cost effectiveness values of all these options for emissions
reductions are estimated to be $7,033 per ton of methane reduced and
$33,049 per ton of VOC reduced. Both of these values are above what the
EPA has historically considered to be cost reasonable when determining
the BSER for VOCs and methane under CAA section 111.\134\ As there is
no cost

[[Page 68258]]

effective control option that can achieve the incremental emissions
reductions from 95.0 percent to 100 percent reduction, the EPA proposes
to determine that the NSPS standard for modified and reconstructed
sources and the EG presumptive standard should allow owners and
operators of sources with pumps already controlled by 95.0 percent to
continue to use and maintain those controls rather than undertake
costly capital improvement projects to switch to emissions controls
that result in only 5 more percentage points emissions reductions than
achieved with the use of the controlled pumps. Therefore, the EPA
proposes to include an alternative standard for modified and
reconstructed facilities under NSPS OOOOb and the presumptive standards
in EG OOOOc to take into account the updated BSER analysis that
properly considers the incremental costs of converting to zero
emissions for individual pumps within a designed pump facility that are
routed through a CVS to a control device achieving 95.0 percent or
greater control of emissions. This alternative standard would require
these pumps to achieve 95.0 percent or greater control of emissions as
well as meet the compliance requirements for CVSs and control devices
in NSPS OOOOb and EG OOOOc.
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\134\ Cost reasonableness for BSER purposes under CAA section
111 is generally discussed in the March 2024 Final Rule, 89 FR
16864, although the values expressed in that rule would now be
higher based on 2024 dollars. By way of example, the EPA determined
in that 2024 rulemaking that cost effectiveness values of up to
$5,540/ton of VOC reduction were reasonable at that time. By way of
another example, EPA noted in the November 2021 Proposal that the
EPA previously determined that methane cost effectiveness values in
the 2016 NSPS OOOOa of $2,185/ton of methane reduction represented
reasonable costs.
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While the petitioner specifically requested this emissions control
level for pumps that were required to reduce emissions by 95.0 percent
under NSPS OOOOa, the EPA is proposing to determine that this
alternative standard should also be available to other pumps that had
emissions controlled by 95.0 percent on or before December 6, 2022.
There is no difference in the incremental cost effectiveness of going
from 95.0 percent to 100 percent emissions control between those pumps
achieving 95.0 percent control due to NSPS OOOOa requirements and those
that were achieving 95.0 percent emissions control for other reasons,
such as State or local requirements. Therefore, the EPA proposes to
include this alternative standard for all such existing pumps in NSPS
OOOOb (for modified or reconstructed sources) and EG OOOOc.

E. Fugitive Emissions

1. Background
Under the March 2024 Final Rule, NSPS OOOOb includes standards for
fugitive emissions components affected facilities and EG OOOOc includes
presumptive standards for fugitive emissions components designated
facilities. As described in the preamble to the March 2024 Final Rule,
each fugitive emissions components affected facility and each fugitive
emissions components designated facility includes the collection of
fugitive emissions components at a well site, centralized production
facility, or a compressor station.\135\ As defined at 40 CFR 60.5430b
and 60.5430c, fugitive emissions include an indication of emissions
observed from a fugitive emissions component using audible, visual, and
olfactory (AVO), an indication of visible emissions observed from a
fugitive emissions component using an OGI instrument, or an instrument
reading of 500 parts per million by volume (ppmv) or greater from a
fugitive emissions component using EPA Method 21 of appendix A-7 to 40
CFR part 60 (EPA Method 21). 40 CFR 60.5430b defines a fugitive
emissions component as any component that has the potential to emit
fugitive emissions of methane or VOCs at a well site, centralized
production facility, or compressor station. These devices include
valves (including separator dump valves), connectors, pressure relief
devices, open-ended lines, flanges, covers and CVSs not subject to 40
CFR 60.5411b, thief hatches or other openings on a storage vessel not
subject to 40 CFR 60.5395b, compressors, instruments, meters, and yard
piping. Similarly, the EG OOOOc, 40 CFR 60.5430c contains comparable
definitions for fugitive emission components, defined as any component
that has the potential to emit fugitive emissions of methane at a well
site, centralized production facility, or compressor station. This
includes but is not limited to valves (including separator dump
valves), connectors, pressure relief devices, open-ended lines,
flanges, covers and CVSs not subject to 40 CFR 60.5411c, thief hatches
or other openings on a storage vessel not subject to 40 CFR 60.5396c,
compressors, instruments, meters, and yard piping.
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\135\ 89 FR 16871 (March 8, 2024).
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For the NSPS OOOOb, owners and operators of affected facilities
that contain fugitive emission components follow 40 CFR 60.5397b.
Owners and operators of fugitive emission components at affected
facilities must develop and follow the fugitive emissions monitoring
plan for the site consistent with 40 CFR 60.5397b(b), conduct initial
and ongoing fugitive emission monitoring surveys as provided in 40 CFR
60.5397b(f)-(g), repair any source of fugitive emissions that have been
identified as provided in 40 CFR 60.5397b(h), and follow the proper
recordkeeping and reporting procedures as specified in 40 CFR
60.5397b(k). In general terms, after the initial survey, this provision
requires monitoring and repair for the five subcategories of well sites
and compressor stations as follows:
<bullet> Single wellhead only well sites: Quarterly monitoring
using AVO or any other detection method (e.g., EPA Method 21, etc.).
<bullet> Multi-wellhead only well sites: Semiannual OGI (or EPA
Method 21) monitoring and quarterly monitoring using AVO or any other
method.
<bullet> Well sites or centralized production facilities with
specified major production and processing equipment: Quarterly OGI (or
EPA Method 21) monitoring and bimonthly monitoring using AVO or any
other detection method.
<bullet> Small well sites: Quarterly monitoring using AVO or any
other detection method.
<bullet> Compressor stations: Quarterly OGI (or EPA Method 21) and
monthly monitoring using AVO or any other detection method.
The third subcategory includes well sites and centralized
production facilities that have: (1) One or more controlled storage
vessels or tank batteries; (2) one or more control devices; (3) one or
more natural gas-driven process controllers or pumps; or (4) two or
more pieces of major production or processing equipment not listed in
items (1)-(3).\136\
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\136\ 40 CFR 60.5397b(g)(1)(iv)(A)-(D).
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Major production and processing equipment as defined in 40 CFR
60.5430b means reciprocating or centrifugal compressors, glycol
dehydrators, heater/treaters, separators, control devices, natural gas-
driven process controllers, natural gas-driven pumps, and storage
vessels or tank batteries collecting crude oil, condensate,
intermediate hydrocarbon liquids, or produced water, for the purpose of
determining whether a well site is a wellhead only well site.
For the fourth category of small well sites, 40 CFR 60.5430b
defines a small well site, for purposes of the fugitive emissions
standards in 40 CFR 60.5397b and 40 CFR 60.5398b, as a site that
contains a single wellhead, no more than one piece of certain major
production and processing equipment, and associated meters and yard
piping. Small well sites cannot include any

[[Page 68259]]

controlled storage vessels (or controlled tank batteries), control
devices, natural gas-driven process controllers, or natural gas-driven
pumps. The presumptive standards for EG OOOOc contain similar
provisions for fugitive emissions components designated facilities
under 40 CFR 60.5397c.
The March 2024 Final Rule requirements at 40 CFR 60.5397b(c)(2) and
40 CFR 60.5397c(c)(2) do not specifically state that a combination of
fugitive emissions monitoring techniques can be used to comply with the
requirements, and reconsideration petitioners on the March 2024 Final
Rule interpret the term ``technique'' (singular) used in 40 CFR
60.5397b(c)(2) and 40 CFR 60.5397c(c)(2) to mean that only one
technique can be utilized in order to comply with the
requirements.\137\ Reconsideration petitioners expressed concerns with
the clarity of the current rule on this point. See section III.E.2.a of
this preamble for detailed descriptions of these concerns.
---------------------------------------------------------------------------

\137\ 89 FR 16871-16872 (March 8, 2024).
---------------------------------------------------------------------------

The March 2024 Final Rule also includes provisions for difficult-
to-monitor and unsafe-to-monitor fugitive emissions components surveyed
using EPA Method 21.\138\ See 40 CFR 60.5397b(g)(2) and (3). No similar
provisions exist for difficult- and unsafe-to-monitor fugitive
emissions components monitored by other methods, such as AVO
inspections. Reconsideration petitioners requested that the EPA clarify
and add, as needed, provisions for AVO inspections like those provided
for EPA Method 21. See section III.E.2.a of this preamble for
discussion on EPA Method 21 specific provisions for AVO inspections.
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\138\ 40 CFR 60.5397b(g)(2) and (3).
---------------------------------------------------------------------------

The March 2024 Final Rule provides criteria at 40 CFR
60.5365b(i)(2) to determine, for the purposes of the fugitive emissions
components, if a modification of a centralized production facility has
occurred. The EPA received requests to revise the current modification
criteria related to centralized production, with petitioners arguing
that the criteria are inappropriate as these facilities often receive
production from offsite wells operated by different entities, and the
operator of the centralized production facility may be unaware of
offsite activities that could trigger a modification. See section
III.E.2.c of this preamble for discussion on modification criteria for
centralized production facilities.
Under the March 2024 Final Rule, the fugitive emissions monitoring
requirements apply until the site completes the well closure
requirements. These requirements include submission of a well closure
plan that includes permanent plugging of all the wells at the site and
submitting a well closure report.\139\ Owners and operators need to
submit the well closure plan within 30 days of the cessation of
production from all wells located at the site.\140\ The well closure
plan must include a description of the steps necessary to close all the
wells at the site, including permanently plugging those wells; a
description of the financial requirements and disclosure of financial
assurance to complete closure; and details on the schedule for
completing all activities in the well closure plan.\141\ Owners and
operators are also required to submit a notification of intent to close
the well site 60 days prior to starting well closure activities. 40 CFR
60.5397b(l)(2). A final OGI survey is required of the well site after
completing the activities in the well closure plan, with requirements
to take steps to eliminate emissions and resurvey the source if any
emissions are imaged by the OGI instrument, and there are associated
recordkeeping and reporting requirements. 40 CFR 60.5397b(l)(3)-(4).
Reconsideration petitioners requested that the EPA revise the
requirement to notify the Agency prior to well closure. See section
III.E.2.d of this preamble for discussion on the well closure
requirements.
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\139\ 40 CFR 60.5397b(g), 40 CFR 60.5397b(l).
\140\ 40 CFR 60.5397b(l)(1).
\141\ 40 CFR 60.5397b(l)(1).
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2. Additional Background and Summary of Proposed Changes and Rationale
Reconsideration petitioners requested that the EPA reconsider
certain issues related to the March 2024 Final Rule fugitive emissions
monitoring requirements.\142\ This section describes those requests
raised in petitions for reconsideration that are relevant to this
proposal.
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\142\ API-AXPC (2024b)..
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Petitioners requested that the EPA allow operators to develop
flexible, fit-for-purpose monitoring plans that use multiple detection
technologies during each periodic survey. Petitioners also requested
that the EPA add provisions for AVO surveys of difficult-to-monitor and
unsafe-to-monitor fugitive emissions components. See section III.E.2.a
of this preamble for further discussion on both of these issues.
In addition, petitioners asserted that the definition of a fugitive
emissions component should reference certain provisions from NSPS OOOO
and NSPS OOOOa in addition to the provisions already referenced from
NSPS OOOOb. See section III.E.2.b of this preamble for further
discussion of this issue, including petitioners' specific
recommendations.
Furthermore, petitioners claimed that the modification criteria for
fugitive emissions components affected facilities finalized in the
March 2024 Final Rule are inappropriate for certain centralized
production facilities in the gathering and boosting segment.\143\ See
section III.E.2.c of this preamble for further discussion of this
issue.
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\143\ API-AXPC (2024b).. pgs. 22-23.
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Additionally, petitioners asserted that the timing components of
the well closure notification requirements in the March 2024 Final Rule
could impact an operators' ability to timely close the well. See
section III.E.2.d of this preamble for further discussion of this
issue.
a. Fugitive Emissions Monitoring Detection Technologies
Background. Petitioners requested that the EPA clarify that
operators may use AVO, OGI, and/or EPA Method 21 as part of flexible,
fit-for-purpose fugitive emissions monitoring plans. According to
petitioners, the March 2024 Final Rule fails to clarify whether
facilities can use multiple monitoring technologies or whether they
need to use a single technology or method to demonstrate compliance.
Petitioners also requested extensions of difficult-to-monitor and
unsafe-to-monitor provisions for fugitive emissions monitoring surveys
conducted using EPA Method 21 to fugitive emissions monitoring surveys
performed using AVO.
Summary of Proposed Changes and Rationale. The EPA proposes to
revise 40 CFR 60.5397b(c)(2) and 40 CFR 60.5397c(c)(2) of the
regulatory text in NSPS OOOOb and EG OOOOc to refer to ``technique(s)''
(rather than ``technique,'' in the singular) to clarify that owners and
operators have the option to use multiple survey techniques to comply
with requirements based on the appropriate component monitoring survey
method used. The Agency notes that 40 CFR 60.5397b(c)(2) and 40 CFR
60.5397c(c)(2) already include the phrase ``and/or'', suggesting
multiple techniques could be used. The EPA notes that several
individual techniques can be used to determine fugitive emissions on
their own, so using multiple techniques together can also meet the
requirements of these provisions, as long as that use is otherwise
consistent with the relevant

[[Page 68260]]

regulatory requirements. As such, this proposed revision clarifies the
EPA's original intent to allow usage of multiple monitoring methods
rather than restrict owners and operators to a single method.
The NSPS OOOOb and EG OOOOc currently include difficult-to-monitor
and unsafe-to-monitor provisions in 40 CFR 60.5397b(g)(2) and (3), and
in 40 CFR 60.5397c(g)(2) and (3), when facilities use EPA Method 21 to
conduct fugitive emissions monitoring surveys. Considering the
petitioners' request in this regard, the EPA acknowledges their concern
that conducting AVO inspections shares similar monitoring challenges to
conducting monitoring using EPA Method 21 in terms of potential
difficulties or safety concerns when completing the inspection. As with
EPA Method 21 inspections, the operator must visually see components to
conduct an AVO inspection, and this may require the use of a lift or
may require access to potentially unsafe locations. While the EPA
expects fewer components would meet the definition of difficult-to-
monitor and unsafe-to-monitor during an AVO inspection given that AVO
does not have the same direct proximity requirements as EPA Method 21,
the EPA recognizes the petitioners' concern that AVO inspections could
pose similar difficulty and safety issues as those encountered when
monitoring is conducted with EPA Method 21. Thus, the EPA proposes to
amend 40 CFR 60.5397b(g)(2) and (3) and 40 CFR 60.5397c(g)(2) and (3)
to include difficult- and unsafe-to-monitor provisions for AVO
inspections that parallel those in the current rules for monitoring
with EPA Method 21. The EPA solicits comment on this proposal.
(Question III.4a)
In addition, for purposes of setting fugitive emissions monitoring
requirements, the EPA seeks comment (including data and detailed
information) on how often fugitive emissions are found at different
types of sites, the approximate volume of gas emitted during a typical
fugitive emissions event at each type of site, estimates regarding the
approximate length of time that fugitive events last at these sites,
and the cost of conducting fugitive emissions monitoring (e.g., capital
costs, variable costs, changes to business practices, safety
implications of conducting the fugitives monitoring, and any other
relevant costs) . (Question III.4b)
The EPA is also soliciting comment on the cost effectiveness and
cost reasonableness of monitoring requirements for fugitive emissions
generally. The EPA is specifically requesting information on the
appropriate frequency, type of monitoring technology, equivalent
monitoring technologies for various equipment types, and other relevant
information that may improve EPA's cost effectiveness and cost
reasonableness analyses, allowing the EPA to better target of emission
reductions and EPA also seeks comment whether the fugitive emissions
monitoring requirements in the March 2024 Final Rule are necessary
considering this information. The EPA also seeks comment on whether
further distinctions or subcategorizations may be needed to
appropriately target meaningful emissions reductions in a cost
reasonable manner, including potential exemptions of certain
subcategories. (Question III.4c)
b. Definition of Fugitive Emissions Component
Background. Reconsideration petitioners requested that the EPA
revise the definition of fugitive emissions component in the NSPS OOOOb
to include references to the relevant provisions of NSPS OOOO and NSPS
OOOOa as it does for NSPS OOOOb, such that this definition would
exclude covers and CVSs and thief hatches and other openings on a
storage vessel, regulated under NSPS OOOO, NSPS OOOOa, or NSPS OOOOb,
not just NSPS OOOOb. By way of a practical example, if the definition
of fugitive emissions component excludes a thief hatch on an NSPS OOOOb
applicable tank, fugitive surveys would not be required to include the
thief hatch in the fugitive emissions survey conducted under 40 CFR
60.5397b. In this

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