Rule2026-06808
Reconsideration of Standards of Performance for New, Reconstructed, and Modified Sources and Emissions Guidelines for Existing Sources: Oil and Natural Gas Sector Climate Review
Primary source
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Published
April 9, 2026
Effective
June 8, 2026
Issuing agencies
Environmental Protection Agency
Abstract
The U.S. Environmental Protection Agency (EPA) is finalizing amendments to the New Source Performance Standards (NSPS) and Emission Guidelines (EG) for Existing Sources for the Crude Oil and Natural Gas Source Category in response to petitions for reconsideration of the March 8, 2024, final rule. Specifically, this action finalizes discrete technical changes to two aspects of the rules. First, this action finalizes discrete technical changes to the temporary flaring provisions for associated gas in certain situations. Second, this action finalizes discrete technical changes to the vent gas net heating value (NHV) continuous monitoring requirements and alternative performance test (sampling demonstration) option for flares and enclosed combustion device(s) (ECD). In a letter dated May 6, 2024, the EPA notified petitioners and the public that the Agency granted reconsideration on these two aspects of the final rule. These amendments neither finalize changes to any other aspect of the March 8, 2024, final rule, nor finalize alterations to the substance of any emission standards within that final rule. This action also finalizes a technical correction to reinstate regulatory text for the reporting requirements in 40 CFR 60.5420b(b)(1) through (15), which were mistakenly deleted by the December 2025 Final Rule. Also, in this action, the EPA finalizes changes to the regulatory text to meet the Office of the Federal Register formatting and style requirements.
Full Text
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[Federal Register Volume 91, Number 68 (Thursday, April 9, 2026)]
[Rules and Regulations]
[Pages 18056-18132]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-06808]
[[Page 18055]]
Vol. 91
Thursday,
No. 68
April 9, 2026
Part III
Environmental Protection Agency
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40 CFR Part 60
Reconsideration of Standards of Performance for New, Reconstructed, and
Modified Sources and Emissions Guidelines for Existing Sources: Oil and
Natural Gas Sector Climate Review; Final Rule
Federal Register / Vol. 91, No. 68 / Thursday, April 9, 2026 / Rules
and Regulations
[[Page 18056]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 60
[EPA-HQ-OAR-2024-0358; FRL-12031-02-OAR]
RIN 2060-AW35
Reconsideration of 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 (EPA).
ACTION: Final rule.
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SUMMARY: The U.S. Environmental Protection Agency (EPA) is finalizing
amendments to the New Source Performance Standards (NSPS) and Emission
Guidelines (EG) for Existing Sources for the Crude Oil and Natural Gas
Source Category in response to petitions for reconsideration of the
March 8, 2024, final rule. Specifically, this action finalizes discrete
technical changes to two aspects of the rules. First, this action
finalizes discrete technical changes to the temporary flaring
provisions for associated gas in certain situations. Second, this
action finalizes discrete technical changes to the vent gas net heating
value (NHV) continuous monitoring requirements and alternative
performance test (sampling demonstration) option for flares and
enclosed combustion device(s) (ECD). In a letter dated May 6, 2024, the
EPA notified petitioners and the public that the Agency granted
reconsideration on these two aspects of the final rule. These
amendments neither finalize changes to any other aspect of the March 8,
2024, final rule, nor finalize alterations to the substance of any
emission standards within that final rule. This action also finalizes a
technical correction to reinstate regulatory text for the reporting
requirements in 40 CFR 60.5420b(b)(1) through (15), which were
mistakenly deleted by the December 2025 Final Rule. Also, in this
action, the EPA finalizes changes to the regulatory text to meet the
Office of the Federal Register formatting and style requirements.
DATES: This final rule is effective on June 8, 2026. The incorporation
by reference of certain material listed in the rule is approved by the
Director of the Federal Register as of June 8, 2026.
ADDRESSES: The EPA has established a docket for this rulemaking under
Docket ID No. EPA-HQ-OAR-2024-0358. All documents in the docket are
listed on the <a href="https://www.regulations.gov/">https://www.regulations.gov/</a> website. Although listed,
some information is not publicly available, e.g., Confidential Business
Information (CBI) or other information whose disclosure is restricted
by statute. Certain other material, such as copyrighted material, is
not placed on the internet and will be publicly available only in hard
copy form. Publicly available docket materials are available
electronically through <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>.
FOR FURTHER INFORMATION CONTACT: For questions about this final rule,
contact Amy Hambrick, Natural Resources Division (E143-05), Office of
Clean Air Programs, U.S. Environmental Protection Agency, 109 T.W.
Alexander Drive, P.O. Box 12055 RTP, North Carolina 27711; telephone
number: (919) 541-0964; and email address: <a href="/cdn-cgi/l/email-protection#3b535a565949525850155a56427b5e4b5a155c544d"><span class="__cf_email__" data-cfemail="fe969f939c8c979d95d09f9387be9b8e9fd0999188">[email protected]</span></a>.
Additional questions may be directed to the following email address:
<a href="/cdn-cgi/l/email-protection#58177e1f153d2c3039363d0a2d343d183d2839763f372e"><span class="__cf_email__" data-cfemail="632c45242e06170b020d0631160f06230613024d040c15">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Preamble acronyms and abbreviations. Throughout this document the
use of ``we,'' ``us,'' or ``our'' is intended to refer to the EPA. We
use multiple acronyms and terms in this preamble. While this list may
not be exhaustive, to ease the reading of this preamble and for
reference purposes, the EPA defines the following terms and acronyms
here:
ALT alternative
AGR acid gas removal
APA Administrative Procedure Act
API American Petroleum Institute
ASTM American Society for Testing and Materials
AXPC American Exploration and Production Council
BSER best system of emission reduction
Btu/lb British thermal units per pound
Btu/scf British thermal units per standard cubic feet
[deg]C degrees Celsius
CAA Clean Air Act
CBI Confidential Business Information
CFR Code of Federal Regulations
CO<INF>2</INF> carbon dioxide
CRA Congressional Review Act
DRE destruction removal efficiency
ECD enclosed combustion device(s)
EG emissions guidelines
EIA U.S. Energy Information Administration
EOR enhanced oil recovery
EPA U.S. Environmental Protection Agency
FR Federal Register
GC gas chromatograph
GHG greenhouse gas
HP high-pressure
H<INF>2</INF>S hydrogen sulfide
ICR information collection request
IFR interim final rule
LP low-pressure
MACT maximum achievable control technology
MCF thousand cubic feet
MS mass spectrometer
NAICS North American Industry Classification System
NHV net heating value(s)
NHV<INF>cz</INF> combustion zone NHV
NHV<INF>dil</INF> NHV dilution parameter
NRU nitrogen removal units
NSPS new source performance standards
NTTAA National Technology Transfer and Advancement Act
OGI Optical Gas Imaging
OMB Office of Management and Budget
PRA Paperwork Reduction Act
RFA Regulatory Flexibility Act
RLSO redline strike out
RTC Response to Comment
scf standard cubic feet
TAR Tribal Authority Rule
TCEQ Texas Commission on Environmental Quality
TXOGA Texas Oil and Gas Association
UMRA Unfunded Mandates Reform Act
U.S. United States
VISR Video Imaging Spectro-Radiometry
VOC volatile organic compound(s)
Organization of this document. The information in this preamble is
organized as follows:
I. General Information
A. Executive Summary
B. Does this action apply to me?
C. Where can I get a copy of this document and other related
information?
II. Statutory Background and Regulatory History
A. Statutory Background of CAA Sections 111(b), 111(d), and
General Implementing Regulations
B. What is the regulatory history and background of NSPS and EG
for the Crude Oil and Natural Gas source category?
C. Judicial Review and Administrative Review
III. Summary of Final Amendments to NSPS OOOOb and EG OOOOc
A. Temporary Flaring Provisions for Associated Gas in Certain
Situations
B. Vent Gas NHV Continuous Monitoring Requirements and
Alternative Performance Test (Sampling Demonstration) Option for
Flares and Enclosed Combustion Devices
C. Correction of Inadvertent Deletion of Regulatory Text
IV. Significant Comments and Changes Since Proposal for NSPS OOOOb
and EG OOOOc
A. Temporary Flaring Provisions for Associated Gas in Certain
Situations
B. Vent Gas NHV Continuous Monitoring Requirements and
Alternative Performance Test (Sampling Demonstration) Option for
Flares and Enclosed Combustion Device
V. How do these final amendments impact the implementation of EG
OOOOc?
VI. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
B. Executive Order 14192: Unleashing Prosperity Through
Deregulation
[[Page 18057]]
C. Paperwork Reduction Act (PRA)
D. Regulatory Flexibility Act (RFA)
E. Unfunded Mandates Reform Act (UMRA)
F. Executive Order 13132: Federalism
G. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
H. Executive Order 13045: Protection of Children From
Environmental Health Risks and Safety Risks
I. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
J. National Technology Transfer and Advancement Act (NTTAA) and
1 CFR Part 51
K. Congressional Review Act (CRA)
I. General Information
A. Executive Summary
1. Purpose of the Regulatory Action
On March 8, 2024, the EPA published a final rule for the Crude Oil
and Natural Gas source category under CAA section 111(b) and (d) at 89
FR 16820 (``March 2024 Final Rule''). The EPA finalized NSPS OOOOb for
GHG and VOC emissions from new, modified, and reconstructed sources in
this source category. The EPA also finalized EG OOOOc for GHG emissions
from existing sources in this source category. The March 2024 Final
Rule became effective on May 7, 2024. The March 2024 Final Rule applies
to thousands of new sources and will apply to hundreds of thousands of
existing sources when the EG is implemented 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;
and natural gas production applicability includes processing,
transmission, and storage, which includes the well and extends to, but
does not include, the local distribution company custody transfer
station.
After the publication of the March 2024 Final Rule, the EPA
received multiple petitions \1\ for reconsideration. On May 6, 2024, we
notified certain petitioners and the public that we granted
reconsideration on two 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 and
alternative performance test (sampling demonstration) option for flares
and enclosed combustion devices.\2\
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\1\ See Docket No. EPA-HQ-OAR-2024-0358 for petitions for
reconsideration received.
\2\ See Docket No. EPA-HQ-OAR-2024-0358 for May 6, 2024, letter
granting reconsideration.
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On January 15, 2025, the EPA proposed amendments to the New Source
Performance Standards and Emission Guidelines for Existing Sources for
the Crude Oil and Natural Gas Source Category in response to these
petitions for reconsideration (``January 2025 Proposal'').\3\
Specifically, we proposed discrete technical changes to two different
aspects of the rules (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).\.\ This action finalizes amendments to
the March 2024 Final Rule resulting from our reconsideration of these
two discrete issues.\4\
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\3\ 90 FR 3734 (January 15, 2025).
\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 20, 2025, the President issued Executive Orders 14154
(Unleashing American Energy) \5\ and 14156 (Declaring a National Energy
Emergency).\6\ Then, on January 31, 2025, the President issued
Executive Order 14192 (Unleashing Prosperity through Deregulation).\7\
On March 12, 2025, against this backdrop, the EPA announced plans for
deregulatory actions to, among other things, unleash American
energy.\8\ On that same day, and as part of the larger Agency plan, the
EPA announced plans to reconsider the regulations promulgated via the
March 2024 Final Rule ``to ensure they do not prevent America from
unleashing energy dominance.'' \9\
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\5\ 90 FR 8353 (January 29, 2025).
\6\ 90 FR 8433 (January 29, 2025).
\7\ 90 FR 9065 (February 6, 2025).
\8\ <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>.
\9\ <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>.
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On July 31, 2025, the EPA promulgated an IFR which extended
deadlines for certain provisions related to control devices, equipment
leaks, storage vessels, process controllers, and covers and closed vent
systems in the NSPS OOOOb.\10\ 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 the EG OOOOc. In December
2025, the EPA promulgated a final rule which responded to comments
received on the July 2025 IFR and concluded that the regulatory
amendments made in the IFR were still appropriate after consideration
of comments.\11\ In response to comments received, the December 2025
Final Rule also 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 ECD 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 or operators to submit initial annual reports pursuant to 40 CFR
60.5420(b).\12\
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\10\ 90 FR 35966 (July 31, 2025).
\11\ 90 FR 55671 (December 3, 2025).
\12\ See 90 FR at 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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In this final rule, the EPA is finalizing changes to two aspects of
the March 2024 Final Rule (i.e., temporary flaring and NHV monitoring)
after consideration of comments received on the January 2025 Proposal.
First, this action finalizes discrete technical changes to the
temporary flaring provisions for associated gas in certain situations.
These changes include:
<bullet> Extending the baseline time limit for temporary flaring of
associated gas in certain situations from 24 hours to 72 hours with
allowances to go beyond 72 hours in the event of exigent circumstances
such as extreme inclement weather that prevent an owner or operator
from safely accessing a well site to resolve an emergency or
maintenance issue:
[cir] Requiring owners and operators to cease flaring as soon as
the malfunction is resolved or the temporary flaring limit is reached,
whichever occurs first, and
[cir] Clarifying recordkeeping and reporting requirements to
include a written description of the exigent circumstance, steps taken
to resolve the issue, date and time when it took place, and the total
duration of flaring.
Second, this action finalizes discrete technical changes to the
vent gas net heating value (NHV) continuous monitoring requirements and
alternative performance test (sampling demonstration) option for flares
and ECDs. These changes include:
<bullet> Revising numerous aspects of vent gas NHV continuous
monitoring requirements and alternative performance test (sampling
demonstration) options for flares and enclosed combustion devices by:
[[Page 18058]]
[cir] Expanding gas streams that are exempt from monitoring due to
high NHV content to include all flare types (unassisted and assisted),
as well as ECDs for both new and existing sources, and
[cir] Requiring NHV monitoring via continuous monitoring or
alternative sampling demonstration in cases where inert gases are
added, or for other miscellaneous scenarios which decrease the NHV
content of the inlet gas stream for all flare types and ECDs for both
new and existing sources.
2. Summary of the Major Provisions of This Regulatory Action
After considering comments received on the January 2025 Proposal,
the EPA is allowing up to 72 hours for certain types of temporary
flaring of associated gas based on information indicating that more
than 24 or 48 hours is needed in some instances. While we acknowledge
owners or operators have an economic incentive not to flare due to
product (natural gas) loss that can equate to lost revenue, we have
included a backstop requirement that owners or operators cease flaring
after resolving the incident causing the need to flare. Collectively,
the EPA is increasing the allowance of temporary flaring to 72 hours
and including a backstop requirement, so owners or operators have both
the economic incentive and a regulatory obligation to cease flaring of
associated gas after an equipment malfunction or failure is addressed.
Additionally, the EPA solicited comments in the January 2025
Proposal on specific situations that would be considered ``exigent
circumstances.'' Based on comments received and a re-assessment of data
provided to the EPA, we are finalizing an allowance to flare for
greater than 72 hours if an exigent circumstance persists and there is
a need to extend the temporary flaring duration for maintenance, safety
issues, or repairs. While we expect that the vast majority of temporary
flaring situations to be addressed within the 72-hour timeframe, we
recognize that there may be equipment malfunction incidents that
require more than 72 hours to resolve due to circumstances beyond an
owner's or operator's control. However, to ensure flaring does not
continue beyond the time that is necessary to resolve a malfunction
incident, we are including a backstop to this extended timeframe of
flaring until such equipment malfunctions during these exigent
circumstances are resolved or no longer present, whichever is sooner.
After considering input from commenters, the EPA is finalizing that
an ``exigent circumstance'' must be a situation that restricts an
owner's or operator's ability to reasonably access a site with the
necessary equipment and personnel to address and resolve equipment
malfunction incidents that cause the need to temporarily flare
associated gas for more than 72 hours.
Lastly, the EPA is finalizing recordkeeping and reporting
requirements when exigent circumstances are invoked. The EPA
anticipates that exigent circumstances will be invoked only in limited
cases, and that these additional recordkeeping and reporting
requirements will not add undue burden to owners and operators.
The March 2024 Final Rule requires owners and operators to perform
NHV sampling for flares and ECD through continuous monitoring of NHV or
through periodic testing with sampling demonstrations. Industry
petitioners submitted reconsideration petitions in response to the
January 2025 proposal claiming that the compliance demonstrations are
unnecessary, technically infeasible, and provide a limited timeline for
compliance. The petitioners argued that over 99 percent of historical
Btu stream data already complies with the prescribed minimum NHV
content values (depending on flare type) outlined in the March 2024
Final Rule. Industry petitioners asserted that NHV content is usually a
concern when inert gases are added to the process streams, which
typically occurs during scheduled situations and is known to the
operator of the affected source. The EPA made amendments to the NHV
provisions based on data submitted by industry supporting their claims
that the majority (over 99 percent) of facilities already complied with
the minimum NHV requirements, and NHV content is only a concern when
inert gases (and other miscellaneous scenarios) are added to the
process streams.
Based on information from these petitions, as well as further
information provided by industry following the January 2025 proposal,
the EPA is finalizing changes to the continuous monitoring requirements
and alternative performance test options (sampling demonstration) of
NHV for flares and ECD. First, the EPA is expanding the gas streams
that are exempt from monitoring due to high NHV content to include all
flare and ECD for both new and existing sources. However, the EPA is
also requiring that NHV monitoring be performed (via either continuous
monitoring or the alternative performance test (sampling demonstration)
option currently prescribed in the NSPS OOOOb and EG OOOOc regulations)
in cases where inert gases are added and for other miscellaneous
scenarios which decrease the NHV content of the inlet stream gas to all
flare and ECD for both new and existing sources. In addition, the EPA
is providing additional flexibility for alternative performance testing
via the NHV grab sampling option by allowing samples to be taken
upstream of the control device, provided that the sample is
representative of the gas being introduced to the control device.
Additionally, we are finalizing as proposed to allow breaks during
weekends and holidays for the March 2024 Final Rule's consecutive 14-
day sampling demonstration requirements to account for reasonable
operational pauses provided no sampling is spaced more than 3 operating
days apart from the previous sampling day. The EPA is also allowing
less than one-hour sampling times in cases where low or intermittent
flow makes it infeasible for both NSPS OOOOb and EG OOOOC sources,
provided the sampling time used and reason for the reduced sampling
time is documented and reported. Finally, the EPA is clarifying NHV
testing must be reported in volumetric units (Btu/scf) instead of
specific units (Btu/lb) in order to facilitate consistency in
reporting.
This action also finalizes a technical correction to reinstate
regulatory text for the reporting requirements in 40 CFR 60.5420b(b)(1)
through (15), which were mistakenly deleted by the December 2025 Final
Rule,\13\ under the authority of section 553(b)(B) of the
Administrative Procedure Act, 5 U.S.C. 553(b)(B), which states, when an
agency for good cause finds that public notice and comment procedures
are impracticable, unnecessary, or contrary to the public interest, the
agency may issue a rule without providing notice and an opportunity for
public comment. Lastly, in this action, the EPA is finalizing
formatting changes to the regulatory text to meet the required
formatting standards of the Office of the Federal Register.\14\
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\13\ 90 FR 55671 (December 3, 2025).
\14\ To view the final formatting changes, see the full redline
strike out (RLSO) of the regulatory text located in the public
docket at EPA-HQ-OAR-2024-0358.
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3. Costs and Benefits
The EPA estimated present values (PV) and equivalent annualized
values (EAV) of the estimated cost savings of this final
reconsideration in 2024 dollars over the 2024 to 2038 period. The cost
savings are represented in this analysis as the reduction in the number
of affected sources and a reduction in the number of tests required for
each affected source for the changes finalized
[[Page 18059]]
in this reconsideration. In simple terms, these cost savings are an
estimate of the decreased industry expenditures resulting from the
final changes to the March 2024 Final Rule requirements. Under this
final action, emissions changes and benefits from emission changes were
not quantified. Qualitatively, the changes to the temporary flaring
limitation could result in increases to emissions, while we do not
expect any emissions changes to result from the changes to the NHV
testing compliance demonstration.
Table 1 presents the estimated cost savings 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 EIA). This table
presents the PV and EAV of these estimates discounted at three percent
and seven percent.
Table 1--Present Value and Equivalent Annualized Value of Compliance Cost Savings Estimates of the Final Action
From 2024-2038
[Millions of 2024$]
----------------------------------------------------------------------------------------------------------------
3 Percent discount rate 7 Percent discount rate
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Present Value........................................... 2,480 1,900
Equivalent Annualized Value............................. 208 209
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B. Does this action apply to me?
The source category that is the subject of this final action is the
Crude Oil and Natural Gas Source Category regulated under Clean Air Act
(CAA) section 111 through New Source Performance Standards (NSPS) and
Emission Guidelines (EG). The 2022 North American Industry
Classification System (NAICS) codes for the source category are
summarized in Table 2. The NAICS codes serve as a guide for readers
outlining the entities that this final action is likely to affect. 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 1, Federal,
State, and local government entities would not be affected by the NSPS
action.
Table 2--Industrial Source Categories Affected by NSPS Action
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Examples of
Category NAICS code regulated entities
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Industry.......................... 211120 Crude Petroleum
Extraction.
211130 Natural Gas
Extraction.
221210 Natural Gas
Distribution.
486110 Pipeline
Distribution of
Crude Oil.
486210 Pipeline
Transportation of
Natural Gas.
Federal Government................ .............. Not affected.
State and Local Government........ .............. Not affected.
Tribal Government................. 921150 American Indian and
Alaska Native
Tribal Governments.
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This table is not intended to be exhaustive but rather provides a
guide for readers regarding entities likely to be affected by this
action. Other types of entities not listed in the table could also be
affected by this action. To determine whether your entity is affected
by this action, you should carefully examine the applicability criteria
found in NSPS OOOOb and EG OOOOc. If you have questions regarding the
applicability of this action to a particular entity, consult the person
listed in the FOR FURTHER INFORMATION CONTACT section, your State air
pollution control agency with delegated authority for NSPS OOOOb, or
your EPA Regional Office.
The issuance of the CAA section 111(d) EG in March of 2024 did not
impose binding requirements directly on existing sources. The EG
codified in 40 CFR part 60, subpart OOOOc, apply to States in the
development, submittal, and implementation of State plans to establish
performance standards to reduce emissions of greenhouse gas (GHG) in
the form of limitations on methane from designated facilities that
commence construction, modification, or reconstruction on or before
December 6, 2022. Under the Tribal Authority Rule (TAR), eligible
Tribes may seek approval to implement a plan under CAA section 111(d)
in a manner similar to a State. See 40 CFR part 49, subpart A. Tribes
may, but are not required to, seek approval for treatment as a State
for purposes of developing a Tribal Implementation Plan (TIP)
implementing the EG codified in 40 CFR part 60, subpart OOOOc. The TAR
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 authority from the EPA to establish a TIP, the EPA has
authority to establish a Federal CAA section 111(d) plan for designated
facilities that are located in areas of Indian country.\15\ A Federal
plan would apply to all designated facilities located in the areas of
Indian country unless the EPA approves a TIP applicable to those
facilities.
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\15\ 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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C. Where can I get a copy of this document and other related
information?
In addition to being available in the docket, an electronic copy of
this action is available on the internet. A brief summary of this final
rule is available at <a href="https://www.regulations.gov">https://www.regulations.gov</a>, Docket ID No. EPA-HQ-
OAR-2024-0358. Following signature by the EPA Administrator, the EPA
will post a copy of this final action 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>. Following
publication in the Federal
[[Page 18060]]
Register, the EPA will post the Federal Register version of the final
rule and key technical documents at this same website.
A memorandum showing the edits to 40 CFR part 60 subpart OOOOb and
40 CFR part 60 subpart OOOOc finalized in this action is available in
the docket for this action (Docket ID No. EPA-HQ-OAR-2024-0358).
Following signature by the EPA 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>.
II. Statutory Background and Regulatory History
A. CAA Sections 111(b) and 111(d)
The EPA's authority for this rulemaking is CAA section 111, 42
U.S.C. 7411, which governs the establishment of standards of
performance for stationary sources. This CAA section requires the EPA
to list source categories to be regulated, establish standards of
performance for air pollutants emitted by new sources in that source
category, and promulgate EG for States to establish standards of
performance for certain pollutants emitted by existing sources in that
source category. For more information on the statutory background of
CAA sections 111(b) and 111(d), and general implementing regulations,
refer to the discussion provided in section IV.A (Statutory Background
of the CAA sections 111(b), 111(d), and General Implementing
Regulations) of the March 2024 final rule preamble. (89 FR 16846-16848;
March 8, 2024).
B. What is the regulatory history and background of NSPS and EG for the
Crude Oil and Natural Gas source category?
On November 15, 2021, the EPA published a ``proposed rule''
(``November 2021 Action'') to reduce GHG and volatile organic compound
(VOC) emissions from the oil and natural gas industry, specifically the
Crude Oil and Natural Gas source category, but did not provide proposed
regulatory text. In the November 2021 Action, the EPA discussed new
standards of performance under CAA section 111(b) for GHG and VOC
emissions from new, modified, and reconstructed sources in this source
category, as well as changes to standards of performance already
codified at 40 CFR part 60, subparts OOOO and OOOOa. The EPA also
proposed EG under CAA section 111(d) for GHG emissions from existing
sources in this source category for the first time. The EPA also
discussed a protocol under the NSPS general provisions for optical gas
imaging (OGI).
On December 6, 2022, the EPA published a supplemental proposed rule
(``December 2022 Supplemental Proposal'') that addressed two additional
issues. First, the EPA proposed to update and expand the NSPS OOOOb
standards in the November 2021 Action for GHG and VOC emissions from
new, modified, and reconstructed sources. Second, the EPA proposed to
update and expand the EG OOOOc standards in the November 2021 Action
for GHG emissions from existing sources. For purposes of EG OOOOc, the
EPA also proposed implementation requirements for State plans.
On March 8, 2024, the EPA published a final rule for the Crude Oil
and Natural Gas source category under CAA section 111(b) and (d) at 89
FR 16820 (``March 2024 Final Rule''). The EPA finalized NSPS OOOOb for
GHG and VOC emissions from new, modified, and reconstructed sources in
this source category. The EPA also finalized EG OOOOc for GHG emissions
from existing sources in this source category. The March 2024 Final
Rule became effective on May 7, 2024. The March 2024 Final Rule applies
to thousands of new sources and will apply to hundreds of thousands of
existing sources when the EG is implemented 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;
and natural gas production applicability includes processing,
transmission, and storage, which includes the well and extends to, but
does not include, the local distribution company custody transfer
station.
After the publication of the March 2024 Final Rule, the EPA
identified, through its own internal reassessment, 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). The EPA published an IFR
\16\ which made minor and non-substantive corrections to the identified
inadvertent errors in the March 2024 Final Rule.
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\16\ 89 FR 62872 (August 1, 2024); Document ID No. EPA-HQ-OAR-
2021-0317-4057.
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Further, after the publication of the March 2024 Final Rule, the
EPA received multiple petitions \17\ for reconsideration. On May 6,
2024, we notified certain petitioners and the public that we granted
reconsideration on two 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 and
alternative performance test (sampling demonstration) option for flares
and enclosed combustion devices.\18\ The American Petroleum Institute
(API) and the AXPC,<SUP>19 20</SUP> the TXOGA,\21\ the GPA
Midstream,\22\ and the Environmental Integrity Project \23\ submitted
petitions for reconsideration on those issues. This action finalizes
amendments to the March 2024 Final Rule resulting from our
reconsideration of these two discrete issues.\24\
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\17\ See Docket No. EPA-HQ-OAR-2024-0358 for petitions for
reconsideration received.
\18\ See Docket No. EPA-HQ-OAR-2024-0358 for May 6, 2024, letter
granting reconsideration.
\19\ Letter to Michael S. Regan, EPA Administrator, from API and
AXPC. Re: Provisions in the EPA's Final Rule ``New Source
Performance Standards and Emission Guidelines for Crude Oil and
Natural Gas Facilities: Climate Review.'' Reconsideration of the
Final Rule. April 5, 2024. Hereinafter referred to as the ``April
2024 API and AXPC petition.''
\20\ Letter to Michael S. Regan, EPA Administrator, from API and
AXPC. 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.
Hereinafter referred to as the ``May 2024 API and AXPC petition.''
\21\ Letter to Michael S. Regan, EPA Administrator, from TXOGA.
Request for Reconsideration of the EPA's Final Rule ``New Source
Performance Standards and Emission Guidelines for Crude Oil and
Natural Gas Facilities: Climate Review.'' May 7, 2024. Hereinafter
referred to as the ``May 2024 TXOGA petition.''
\22\ Letter to Michael S. Regan, EPA Administrator; Gautam
Srinivasan, Associate General Counsel, EPA; and Amy Hambrick, SPPD,
EPA; from GPA Midstream Association. GPA Midstream Association
Petition for Reconsideration and Request for Stay of Standards of
Performance for New, Reconstructed, and Modified Sources and
Emissions Guidelines for Existing Sources: Oil and Natural Gas
Sector Climate Review. May 2, 2024. Hereinafter referred to as the
``May 2024 GPA Midstream petition.''
\23\ Letter to Michael S. Regan, EPA Administrator, from Air
Alliance Houston; Clean Air Council; and Environmental Integrity
Project. Re: Petition for Reconsideration of the Standards of
Performance for New, Reconstructed, and Modified Sources and
Emissions Guidelines for Existing Sources: Oil and Natural Gas
Sector Climate Review; Final Rule, 89 FR 16,820 (March 8, 2024),
Docket No. EPA-HQ-OAR-2021-0317. May 7, 2024. Hereinafter referred
to as the ``May 2024 EIP et al. petition.''
\24\ 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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[[Page 18061]]
On January 20, 2025, the President issued Executive Orders 14154
(Unleashing American Energy) \25\ and 14156 (Declaring a National
Energy Emergency).\26\ Then, on January 31, 2025, the President issued
Executive Order 14192 (Unleashing Prosperity through Deregulation).\27\
On March 12, 2025, against this backdrop, the EPA announced plans for
deregulatory actions to, among other things, unleash American
energy.\28\ On that same day, and as part of the larger Agency plan,
the EPA announced plans to reconsider the regulations promulgated via
the March 2024 Final Rule ``to ensure they do not prevent America from
unleashing energy dominance.'' \29\
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\25\ 90 FR 8353 (January 29, 2025).
\26\ 90 FR 8433 (January 29, 2025).
\27\ 90 FR 9065 (February 6, 2025).
\28\ <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>.
\29\ <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>.
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On July 31, 2025, the EPA promulgated an IFR which extended
deadlines for certain provisions related to control devices, equipment
leaks, storage vessels, process controllers, and covers and closed vent
systems in the NSPS OOOOb.\30\ 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 the EG OOOOc. In December
2025, the EPA promulgated a final rule which responded to comments
received on the July 2025 IFR and concluded that the regulatory
amendments made in the IFR were still appropriate after consideration
of comments.\31\ In response to comments received, the December 2025
Final Rule also 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 ECD 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 or operators to submit initial annual reports pursuant to 40 CFR
60.5420(b).\32\
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\30\ 90 FR 35966 (July 31, 2025).
\31\ 90 FR 55671 (December 3, 2025).
\32\ See 90 FR at 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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C. Judicial Review and Administrative Review
Under CAA section 307(b)(1), judicial review of this final
rulemaking is available only by filing a petition for review in the
United States Court of Appeals for the District of Columbia Circuit by
June 8, 2026. Under CAA section 307(b)(2), the requirements established
by this final rule may not be challenged separately in any civil or
criminal proceedings brought by the EPA to enforce the requirements. 42
U.S.C. 7607(b)(1)-(2).
CAA section 307(d)(7)(B) further provides that ``[o]nly an
objection to a rule or procedure which was raised with reasonable
specificity during the period for public comment (including any public
hearing) may be raised during judicial review.'' This section also
provides a mechanism for the EPA to convene a proceeding for
reconsideration ``[i]f the person raising an objection can demonstrate
to the EPA that it was impracticable to raise such objection within
[the period for public comment] or if the grounds for such objection
arose after the period for public comment, (but within the time
specified for judicial review) and if such objection is of central
relevance to the outcome of the rule.'' 42 U.S.C. 7607(d)(7)(B). Any
person seeking to make such a demonstration to us should submit a
Petition for Reconsideration to the Office of the Administrator, U.S.
Environmental Protection Agency, Room 3000, WJC South Building, 1200
Pennsylvania Ave. NW, Washington, DC 20460, with a copy to both the
person(s) listed in the preceding FOR FURTHER INFORMATION CONTACT
section, and the Associate General Counsel for the Air and Radiation
Law Office, Office of General Counsel (Mail Code 2344A), U.S.
Environmental Protection Agency, 1200 Pennsylvania Ave. NW, Washington,
DC 20460.
III. Summary of Final Amendments to NSPS OOOOb and EG OOOOc
The amendments in this final action relate to two 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 and alternative performance test (sampling demonstration)
option for flares and enclosed combustion devices. The two issues
addressed in this final rule are separate and distinct from each other.
Each of these two issues concern different portions of the March 2024
Final Rule that do not rely on the other. This action also finalizes a
technical correction to reinstate regulatory text for the reporting
requirements in 40 CFR 60.5420b(b)(1) through (15), which were
mistakenly deleted by the December 2025 Final Rule.\33\ Also, in this
action, the EPA is finalizing formatting changes to the regulatory text
to meet the required formatting standards of the Office of the Federal
Register.\34\
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\33\ 90 FR 55671 (December 3, 2025).
\34\ To view the final formatting changes, see the full redline
strike out (RLSO) of the regulatory text located in the public
docket at EPA-HQ-OAR-2024-0358.
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Each regulatory change included in this final action is severable
from the other. First, each of the two groups of substantive provisions
amended in this action (temporary flaring of associated gas and vent
gas NHV) is functionally independent from the other--i.e., may operate
in practice independently of the other requirements being amended here,
such that the amendment of one set of requirements does not turn on the
amendment of any other set of requirements. Put another way, the
amendments to the temporary flaring provisions in no way impact or
depend on the separate amendments to the NHV provisions. The same is
true in the opposite direction. The amendments to the NHV provisions in
no way impact or depend on the separate amendments to the temporary
flaring provisions. Second, as explained in this final rule preamble
and the preamble to the proposed rule, the reasoning for each
regulatory change is distinct and independent from the others. For
example, amendments to the NHV provisions are separately justified from
the amendments made to the temporary flaring of associated gas
provisions. Again, the same is true in the opposite direction.
Amendments to the temporary flaring of associated gas provisions are
separately justified from the amendments made to the NHV provisions.
Likewise, the formatting changes are also separate, distinct, and
severable.
A. Temporary Flaring Provisions for Associated Gas in Certain
Situations
Section XI.F.2 of the March 2024 Final Rule preamble presents a
discussion of reasons why an owner or operator would need to flare or
vent associated gas. Based on the reasons set out in that preamble, the
EPA in the March 2024 Final Rule allowed owners and operators to
temporarily route associated gas to a flare or control device for 24
hours in certain situations, including during a deviation caused by a
malfunction (including for reasons of safety) and during repair,
maintenance such as blowdowns, a bradenhead test, a packer leakage
test, a production test, or commissioning. On January 15, 2025, the EPA
proposed extending the allowable time for these situations from
[[Page 18062]]
24 hours to 48 hours (``January 2025 Proposal'').\35\ The EPA proposed
the extended temporary flaring limit based in part on data provided by
API, which showed that 85 percent of flaring events ended within 46
hours for activities such as maintenance, addressing safety issues, and
repairs.
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\35\ 90 FR 3734 (January 15, 2025).
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As discussed in section III.A.2 of the preamble to the January 2025
Proposal, industry petitioners indicated that the 24-hour limitation
for temporary routing of associated gas to a flare or control device in
the March 2024 Final Rule is not sufficient in situations where a
malfunction or an unintended incident endangers the safety of operator
personnel and the public; as well as during repairs, maintenance
(including blow downs), production tests, and commissioning.
Petitioners claimed that a 72-hour timeframe for temporarily routing
associated gas to a flare or control device for these situations is
more appropriate due to the unique characteristics of some well sites
(e.g., due to the differing location and composition/amount of gas
produced by wells), weather conditions, or a combination of both.
After consideration of comments received on the January 2025
Proposal and revisiting the data API provided to the Agency, the EPA is
finalizing two primary changes to the January 2025 Proposal related to
the temporary flaring of associated gas. First, the EPA finds that
increasing the temporary flaring provisions up to 72 hours is
appropriate. This extended timeframe gives owners and operators enough
time to travel to facilities (including geographically remote
facilities), troubleshoot, obtain necessary equipment, and complete
repairs. It also provides sufficient time to overcome many inclement
weather situations where access to a site may be temporarily limited.
Further, moving to 72 hours will reduce the number of incidents where
invoking exigent circumstances is necessary, thus reducing burden on
the industry. Lastly, the extended timeframe also reduces the need to
shut-in operations (where a well is temporarily closed off to restrict
oil and gas flow and production due to unusual or unsafe conditions) in
situations where the issue(s) cannot be addressed within 24 or 48
hours. Shutting-in operations can often result in the depressurization
of equipment, which may lead to the venting of associated gas to the
atmosphere without control. The venting of associated gas in these
scenarios may exceed the emissions that would have otherwise occurred
if the provisions allowed for an additional 24 hours of flaring thereby
defeating the environmental objectives of the rule.\36\
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\36\ See 89 FR 16843-44 (March 8, 2024), section III.B.2.
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Second, and relatedly, the EPA is requiring owners and operators to
stop temporary flaring when repairs or maintenance are completed to
avoid flaring longer than necessary during an individual incident. If
repair or maintenance is completed within 72 hours, then flaring must
stop at the time of completion. In other words, temporary flaring must
cease as early as practicable and within 72 hours unless the facility
properly invokes the procedures for a longer duration. While the 72
hours is a default maximum duration, if a situation arises that
requires an owner or operator to temporarily flare beyond those 72
hours, then the final rule's additional provisions on exigent
circumstances may apply. See section IV.A.1 of this preamble for
further discussion of exigent circumstances. Also see section IV.A.2
for further discussion on temporary flaring beyond 72 hours.
By finalizing an upper limit of temporary flaring up to 72 hours,
the final rule gives operators room to continue to develop ways to
manage delays tied to these malfunctions and failures. At the same
time, it prevents unnecessary flaring when problems are already fixed,
thereby protecting against unnecessary emissions. This balance
encourages owners and operators to keep improving how they detect and
fix problems while providing flexibility and relief. It also supports
better planning, faster repairs, and the potential for greater emission
reductions in the future.
In summary, the EPA is allowing up to 72 hours for certain types of
temporary flaring of associated gas based on information indicating
that more than 24 or 48 hours is needed in some instances. While we
acknowledge owners or operators have an economic incentive not to flare
due to product (natural gas) loss that can equate to lost revenue, we
have included a backstop requirement that owners or operators cease
flaring after resolving the incident causing the need to flare.
Collectively, the EPA is increasing the allowance of temporary flaring
to 72 hours and including a backstop requirement, so owners or
operators have both the economic incentive and a regulatory obligation
to cease flaring of associated gas after an equipment malfunction or
failure is addressed.
Petitioners raised inclement weather as a circumstance that may
deter an owner or operator from accessing an affected facility site and
as a primary cause for the need to temporarily flare (e.g., frozen gas
lines, power outages). While the API dataset classifies inclement
weather as the cause of 86 flaring events, the dataset classifies the
primary cause of over 600 flaring events as ``[u]nknown'' and these
events exhibited the highest average flaring durations and standard
deviations. While we do not know the exact cause of the over 600
``unknown'' flaring events in API's data set, maintaining a 24-hour
flaring timeframe as promulgated in the March 2024 Final Rule based on
the percentage of reported inclement weather-impacted events only
presents a narrow reading of the data and does not reflect the unknown
flaring events that exhibited the highest flaring durations and
standard deviations. The EPA recognizes that the API data show that
many temporary flaring events are resolved within 24 hours, and even
more within 48 hours. Specifically, 83 percent of the instances were
resolved within 24 hours and 85 percent within 48 hours. The EPA
considered establishing cutoffs at 24 hours or 48 hours. However, the
data indicate that 15 percent of instances could not be resolved within
48 hours. Industry noted that weather is a factor, but not the only
factor, impacting temporary flaring events longer than 24 hours, and
geographically dispersed sites, such as the Willison Basin which
contained the majority (78%) of the >24 hour flaring events, add
additional challenge when responding to flaring events. Other causes of
temporary flaring include non-scheduled maintenance or malfunction,
planned maintenance, repair, or tests, and other issues such as weather
or power outages. We determined based on the data and comments received
on the proposal that establishing a cutoff at 24 hours or 48 hours is
not supported because it necessarily fails to include a portion of the
industry that is meaningful in this context. As such, we are finalizing
an allowance to flare up to 72 hours for most situations, and are
providing a mechanism to go beyond 72 hours to allow owners and
operators the time they need to resolve equipment malfunction incidents
and to include a backstop measure to ensure that temporary flaring does
not continue after a malfunction incident is resolved.
In section III.A.3 of the January 2025 Proposal, the EPA
acknowledged that rare instances may occur in which an owner or
operator encounters a
[[Page 18063]]
malfunction, safety, repair, or maintenance event that requires routing
to a flare or control device beyond the proposed 48-hour duration. To
address such instances, the EPA solicited comments on specific
situations that would be considered ``exigent circumstances.'' Based on
comments received and a re-assessment of data provided to the EPA, we
are finalizing an allowance to flare for greater than 72 hours if an
exigent circumstance persists and there is a need to extend the
temporary flaring duration for maintenance, safety issues, or repairs.
While we expect that the vast majority of temporary flaring situations
to be addressed within the 72-hour timeframe, we recognize that there
may be equipment malfunction incidents that require more than 72 hours
to resolve due to circumstances beyond an owner's or operator's
control. However, to ensure flaring does not continue beyond the time
that is necessary to resolve a malfunction incident, we are including a
backstop to this extended timeframe of flaring until such equipment
malfunctions during these exigent circumstances are resolved or no
longer present, whichever is sooner.
After considering input from commenters, the EPA is finalizing that
an ``exigent circumstance'' must be a situation that restricts an
owner's or operator's ability to reasonably access a site with the
necessary equipment and personnel to address and resolve equipment
malfunction incidents that cause the need to temporarily flare
associated gas for more than 72 hours. Reasonable site access is the
ability of an owner or operator to safely transport the necessary
personnel and equipment to a site experiencing an incident. Examples of
possible situations that could limit site access include, but are not
limited to, road washout from flooding; roads obstructed by snow,
debris, or trees; and unsafe travel conditions from extreme weather,
wildfires, and hazmat emergencies. Impediments to resolving equipment
malfunctions also include when an owner or operator is unable to secure
the required equipment to resolve an equipment malfunction incident due
to reasons beyond an owner's or operator's control (i.e., supply chain
issues), or where there is a temporary shortage of personnel due to
reasons beyond an owner's or operator's control (e.g., a national
pandemic). Examples of possible situations that could limit an owner's
or operator's ability to secure required equipment to resolve an
unexpected malfunction due to reasons beyond an owner's or operator's
control include equipment transportation disruptions, trade disputes,
equipment demand competition or national supply chain issues that cause
major delays in securing parts or even render them unavailable for
extended periods of time.
Not all situations that result in the need for temporary flaring
qualify as exigent circumstances. Put another way, not all situations
that result in the need to temporary flare will qualify as exigent
circumstances. For example, inclement weather that results in equipment
failures at a site, such as gas line freezing and power outages, would
generally not constitute an exigent circumstance weather event if
access to the site is not disrupted and equipment and personnel to
resolve equipment malfunctions or failures are available.
Once the site is accessible and necessary equipment and personnel
are available to resolve an equipment malfunction, flaring can continue
until the malfunction is resolved. However, this must be no longer than
72 hours after the site is accessible, and the necessary equipment and
personnel are available to resolve an equipment malfunction. The
exigent circumstances provisions in the final rule are intended to
accommodate rare instances where an owner or operator needs more than
72 hours to return the site to normal operations due to legitimate
unforeseen circumstances outside of their control. The EPA does not
expect that owners and operators will utilize these provisions often,
and these provisions are not intended to allow for indefinite or long-
term flaring. As always, the EPA may bring an enforcement action
against an owner or operator whose actions do not comport with
applicable regulatory provisions.
Lastly, the EPA is finalizing recordkeeping and reporting
requirements when exigent circumstances are invoked. The EPA
anticipates that exigent circumstances will be invoked only in limited
cases, and that these additional recordkeeping and reporting
requirements will not add undue burden to owners and operators. If an
owner or operator claims that an exigent circumstance occurred and
utilizes the extended temporary flaring timeframe, the owner or
operator must maintain records that include: a written description of
the ``exigent circumstance'' requiring the need to flare or route to a
control device beyond 72 hours; a description of steps taken to resolve
the need for temporary flaring/routing to a control device; the dates
and times an identified ``exigent circumstance'' started and ended
(e.g., when owners or operators are able to access site, when personnel
and/or equipment are available) and the total duration of each
``exigent circumstance''; and the dates and times temporary flaring/
routing to a control device started and ended and the total duration of
temporary flaring/routing to a control device due to the identified
``exigent circumstance.'' We require owners and operators to report
this information in their annual report. Owners and operators are
already required to complete recordkeeping and reporting for temporary
flaring events and the additional recordkeeping and reporting
requirements that would result from the extension of flaring duration
beyond the temporary flaring limit for exigent circumstances should not
impose any additional undue burden on the industry.
B. Vent Gas NHV Continuous Monitoring Requirements and Alternative
Performance Test (Sampling Demonstration) Option for Flares and
Enclosed Combustion Devices
The EPA finalized compliance requirements for continuous monitoring
and initial and periodic performance testing for flares and enclosed
combustion device(s) (ECDs) in the March 2024 Final Rule. Of relevance
here are the requirements for those two control devices regarding the
NHV monitoring requirements and alternative performance test (sampling
demonstration) option. In the March 2024 Final Rule, with exceptions
for catalytic vapor incinerators, boilers and process heaters, and
enclosed combustors where temperature is an indicator of destruction
efficiency, all flares and ECD must maintain the NHV of the gas sent to
it above a minimum NHV if the control device is pressure-assisted or
uses no assist gas.<SUP>37 38</SUP> If an
[[Page 18064]]
owner or operator uses a steam- or air-assisted flare or flare, the
owner or operator must maintain the combustion zone NHV
(NHV<INF>cz</INF>) above a minimum level. If the owner or operator uses
a perimeter assist air ECD or flare, the owner or operator must
maintain the NHV dilution parameter (NHV<INF>dil</INF>) above a minimum
level. The NHV<INF>cz</INF> and NHV<INF>dil</INF> parameter terms
account for the reduction in heating value caused by the introduction
of air and/or steam. These terms were intended to ensure that the
assist gas does not overwhelm the heating value provided by the vent
gas to the point where proper combustion does not occur. Owners or
operators also have the option to apply an alternative test method that
either demonstrates continuous compliance with the combustion
efficiency limit or directly demonstrates continuous compliance with
the NHV<INF>cz</INF> operating limit and, if applicable, the
NHV<INF>dil</INF> operating limit.
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\37\ NHV is the potential energy available in a fuel sample,
which is an indicator of flare performance and combustion
efficiency. More specifically, it is the total energy released when
a substance undergoes complete combustion with oxygen under standard
conditions (i.e., the amount of heat released when gas is burned).
See <a href="https://www.epa.gov/controlling-air-pollution-oil-and-natural-gas-operations/frequently-asked-questions-control-devices#nhv">https://www.epa.gov/controlling-air-pollution-oil-and-natural-gas-operations/frequently-asked-questions-control-devices#nhv</a>.
\38\ In NSPS OOOOb and EG OOOOc, NHV is typically expressed in
units of Btus per standard cubic feet (scf). In the March 2024 Final
Rule, NHV monitoring is used to determine the Btu content of a gas
stream which indicates whether a control device (i.e., a flare or an
ECD) is reaching the required efficiency by combusting at least 95
percent of the pollutants of concern (i.e., methane and/or VOC). The
March 2024 Final Rule requires that an NHV value must be at or above
a certain Btu/scf threshold, depending on the design of the flare or
ECD. An NHV value below the prescribed applicable minimum NHV value
can be an indicator of reduced control device performance and
efficiency at less than an acceptable level.
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Associated gas from a well site affected facility was exempt from
NHV monitoring (i.e., assumed to always have high NHV) under the March
2024 Final Rule. Also under the March 2024 Final Rule, for each flare
and ECD used to control gases other than associated gas from a well
site affected facility, the owner or operator must conduct continuous
monitoring using a calorimeter, gas chromatograph (GC), or mass
spectrometer (MS) in order to determine the NHV of the vent stream.\39\
As an alternative to continuous monitoring of NHV, the March 2024 Final
Rule allows the owner or operator to conduct a performance test to
demonstrate the NHV of the vent stream that consistently exceeds the
applicable NHV operating limit in one of two ways: continuous sampling
for 14 consecutive days plus ongoing (three samples every five years),
or manual sampling (twice daily for 14 consecutive days) plus ongoing
(three samples every five years) sampling.\40\ The March 2024 Final
Rule requires a minimum collection time of at least one hour for each
individual manually collected sample. If inlet gas flow is intermittent
such that collecting 28 samples in 14 days is infeasible, an owner or
operator must continue to collect samples beyond 14 days in order to
collect a minimum of 28 samples.
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\39\ 89 FR 16820 (March 8, 2024).
\40\ See 40 CFR 60.5417b(d)(8)(iii)(A) and 40 CFR
60.5417b(d)(8)(iii)(G) for NSPS OOOOb sources and 40 CFR
60.5417c(d)(8)(iii)(A) and 40 CFR 60.5417c(d)(8)(iii)(G) for EG
OOOOc sources.
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Owners or operators also have the option to use an alternative test
method that demonstrates continuous compliance with the combustion
efficiency limit.<SUP>41 42</SUP> If there are no values of the
combustion efficiency measured by the alternative test method over the
14-day period that are less than 95 percent, the gas stream is
considered to consistently exceed the applicable NHV operating limit
and the owner or operator is not required to continuously monitor or
conduct sampling of the NHV of the inlet gas to the flare or ECD.\43\
Under the March 2024 Final Rule, owners or operators of steam- and air-
assisted flares and ECD also must monitor the vent gas and assist gas
flow rates and calculate NHV<INF>cz</INF> and NHV<INF>dil</INF> in
accordance with the provisions in 40 CFR 63.670 (i.e., the refinery
maximum achievable control technology (MACT) rule, or ``Refinery MACT''
as codified in 40 CFR 63, National Emission Standards for Hazardous Air
Pollutants (NESHAP) subpart CC). Alternatively, owners or operators of
air-assisted flares may provide a one-time demonstration based on
maximum air assist rates, minimum waste gas flow rates (based on
backpressure regulator setting), and minimum NHV from the most recent
sampling rather than continuously monitor vent gas and assist gas flow
rates.\44\
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\41\ Under the provisions outlined in 40 CFR 60.5412b(d) and
60.5415b(f)(1)(xi), sources can request to use an ``equivalent
method'' pursuant to 40 CFR 60.8(b)(2), or ``an alternative method
the results of which [the Administrator] has determined to be
adequate for indicating whether a specific source is in compliance''
pursuant to 40 CFR 60.8(b)(3). The EPA is currently accepting and
reviewing applications for alternative (ALT) test methods for NHV
monitoring in the oil and natural gas sector. See https://
www.epa.gov/emc/oil-and-gas-alternative-test-
methods#:~:text=The%20application%20portal%20can%20be,Air%20Emission%
20Measurement%20Center%20webpage. Since the March 2024 Final Rule's
publication, two alternative test method requests have been approved
by the EPA for use under NSPS subpart OOOOb: (1) ALT-156 Alternative
Test Method to monitor the NHV of the flare combustion zone at
facilities subject to NSPS OOOOb and (2) ALT-157 Alternative Test
Method for determining NHV from gas sent to an ECD or Flare subject
to NSPS OOOOb. A list of the EPA's approved alternative test methods
can be found at <a href="https://www.epa.gov/emc/broadly-applicable-approved-alternative-test-methods">https://www.epa.gov/emc/broadly-applicable-approved-alternative-test-methods</a>.
\42\ Per 40 CFR 60.8(b)(5), the EPA has more general authority
to approve alternative test methods involving ``shorter sampling
times and smaller sample volumes when necessitated by process
variables or other factors.''
\43\ See 40 CFR 60.5417b(d)(8)(iii)(D) and 40 CFR
60.5417c(d)(8)(iii)(D).
\44\ See 40 CFR 63.670(j)(6).
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In this Final Rule, the EPA is revising numerous aspects of the NHV
monitoring and testing provisions in the March 2024 Final Rule. The EPA
presented the rationale for these revisions in section III.B of the
preamble of the January 2025 Proposal, with additional details provided
in section IV.B of this preamble.
The EPA is expanding the gas streams that are exempt from
monitoring due to high NHV content to include all flare and ECD for
both new and existing sources. However, the EPA is also requiring that
NHV monitoring be performed (via either continuous monitoring or the
alternative performance test (sampling demonstration) option currently
prescribed in the NSPS OOOOb and EG OOOOc regulations) in cases where
inert gases are added and for other miscellaneous scenarios which
decrease the NHV content of the inlet stream gas to all flare and ECD
for both new and existing sources.\45\ Examples of these known
operational scenarios include combining acid gas removal (AGR) system
amine regenerator still column vent gas with affected facility vent
gas, combining glycol dehydration unit reboiler vent gas with affected
facility vent gas streams without water removal, high water content in
vent streams from certain storage vessels, and enhanced oil recovery
(EOR) sites in fields using water or carbon dioxide (CO<INF>2</INF>)
flooding. The EPA is finalizing recordkeeping and reporting
requirements to specifically indicate whether the flare or ECD receives
(or does not receive) inert gases (inerts) or other streams which may
lower the NHV of the combined stream, and, if so, a description of the
operating scenario(s) which may lower the NHV of the combined stream
through the introduction of those inert gases or other streams.
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\45\ For the purposes of the NHV compliance provisions, inert
gases (or ``inerts'') are gases that do not readily undergo
combustion. Inert gases consist of or contain high concentrations of
nitrogen, CO<INF>2</INF>, water, or other compounds that have a net
heating value of zero. See 90 FR 3742 (January 15, 2025).
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The EPA is also finalizing, as proposed, to replace the general
exemption from NHV monitoring for associated gas for any control device
used at ``well site affected facilities'' with NHV monitoring that is
more reflective of industry operations, in order to be consistent with
the overall NHV monitoring requirements for all affected OOOOb and
OOOOc sources.\46\
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\46\ 90 FR 3746 (January 15, 2025).
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In addition, when an owner or operator chooses to meet the NHV
compliance demonstration by conducting the alternative performance test
via the NHV grab sampling option, the EPA is finalizing, as proposed, a
clarification that sampling may be conducted upstream of the inlet to
the control device, provided that the sample is representative of the
gas inlet to the
[[Page 18065]]
control device. For example, sampling may be conducted from a location
on the control device piping header, provided the sampling location is
downstream of all waste gas inlets into the header.
The EPA is finalizing, as proposed, a clarification that the NHV of
the vent stream must be determined in British thermal units per
standard cubic feet (Btu/scf), where standard conditions are 20 degrees
Celsius ([deg]C), not British thermal units per pound (Btu/lb). If the
composition is determined in weight percent, those concentrations can
be used, but they will need to be converted to volume percent
(equivalent to mole percent) based on the molecular weight of the
constituents.
The EPA is also finalizing, as proposed, that the 14-day period for
the performance test (sampling demonstration) option must be
consecutive operating days, while also allowing for breaks in
performance testing over weekends and holidays which may occur during
the 14-day sampling period, provided that no sampling day is spaced
more than 3 operating days apart from the previous sampling
day.<SUP>47 48</SUP>
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\47\ In this context, an ``operating day'' is considered a
normal business day of operation (i.e., Monday-Friday), and weekends
and holidays are considered calendar days, but not ``operating
days.''
\48\ However, if the affected source is operating during a given
weekend or holiday, the facility may elect to either sample or not
sample during the weekend or holiday.
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In addition, the EPA is specifying that for the purposes of
determining the hourly average for continuous samples, the average
shall be a block hourly average.\49\ The EPA is not amending the
sampling frequency (i.e., two samples per day for 14 days with an
ongoing demonstration of three samples every five years) for the
performance test (sampling demonstration) option for either NSPS OOOOb
or EG OOOOc.
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\49\ Each block average value for each 1-hour period (or shorter
periods) are to be calculated from all measured data during each
period. If the inlet stream is continuously sampled for 14 days, the
hourly block average will be determined on a noon to 1 p.m., 1 p.m.
to 2 p.m., etc. basis.
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The EPA is also retaining the one-hour minimum sampling time for
the twice daily samples, except in cases where low or intermittent flow
makes one-hour sampling infeasible for both NSPS OOOOb and EG OOOOc
sources. In such a case, the EPA is allowing less than one-hour
sampling times, provided that the sampling time used and the reason for
the reduced sampling time is documented and reported.
The EPA is finalizing, as proposed, a clarification in both NSPS
OOOOb and EG OOOOc to more clearly allow the use of the sampling
methodology alternative to the continuous monitoring in 40 CFR
60.5417b(d)(8)(iii) for all types of air- and steam-assisted flares or
ECD.
Finally, for NSPS OOOOb, the EPA is retaining the NHV<INF>cz</INF>
and NHV<INF>dil</INF> monitoring requirements but more clearly
including the provisions at 40 CFR 60.5417b(d)(8)(vi) to allow for the
use of approved alternative test methods as provided in 40 CFR
60.5412b(d)(1)(i) and (ii) for continuous monitoring of
NHV<INF>cz</INF> and, if applicable, NHV<INF>dil</INF>. We are also
finalizing, as proposed, a clarification in 40 CFR 60.5417b(d)(8)(iv)
regarding when flare flow or assist rates are not required to be
monitored. In addition, as proposed, for EG OOOOc, the EPA is removing
the requirement to comply with and conduct monitoring for
NHV<INF>cz</INF> and NHV<INF>dil</INF> for air- and steam-assisted
flares and ECD used for existing sources. This series of revisions in
EG OOOOc includes changes in the initial compliance requirements for
air- or steam-assisted flares or ECD in 40 CFR 60.5412c, the continuous
compliance requirements for these control devices in 40 CFR 60.5415c,
and the continuous monitoring requirements for these control devices in
40 CFR 60.5417c. We are also finalizing, under EG OOOOc, that air- or
steam-assisted or flares or ECD must meet an increase in the minimum
NHV in the vent gas from 270 to 300 Btu/scf.
C. Correction of Inadvertent Deletion of Regulatory Text
As discussed above, in the July 2025 IFR, the EPA amended certain
compliance deadlines and timeframes for implementation in response to
information received after promulgation of the 2024 Final Rule to
address significant concerns that certain regulatory provisions in the
March 2024 Final Rule were not workable or contained problematic
regulatory language that prevented compliance. On December 3, 2025, the
EPA published a final rule that included discrete changes to specific
regulatory text within 40 CFR part 60 subpart OOOOb (December 2025
Final Rule).\50\ Specifically, the EPA finalized amendments to the
compliance deadline for NHV monitoring and provided additional time for
the submission of initial annual reports at 40 CFR 60.5420b(b). The
amendatory instructions for the final rule inadvertently amended all of
40 CFR 60.5420b(b) paragraph (b) in lieu of just the introductory text
for paragraph (b), as intended. This resulted in the erroneous deletion
of paragraphs 40 CFR 60.5420b(b)(1) through (15), which was neither
intended nor proposed.
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\50\ 90 FR 55671 (December 3, 2025).
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To correct this inadvertent error, the EPA is finalizing a
technical correction to reinstate regulatory text for the reporting
requirements in 40 CFR 60.5420b(b)(1) through (15). The substance of
the December 2025 Final Rule remains unchanged by reinstating this
erroneously-deleted regulatory text. Section 553(b)(B) of the
Administrative Procedure Act, 5 U.S.C. 553(b)(B), provides that, when
an agency for good cause finds that public notice and comment
procedures are impracticable, unnecessary, or contrary to the public
interest, the agency may issue a rule without providing notice and an
opportunity for public comment. The EPA has determined that there is
good cause for making this technical correction final without prior
proposal. Such notice and opportunity for comment is unnecessary, as
this technical correction restores the unintentional deletion of
regulatory text made by the regulatory revisions associated with the
December 2025 Final Rule.
The application of the APA's ``good cause'' exemption in this final
rule is limited to correcting the inadvertent deletion of 40 CFR
60.5420b(b)(1) through (15) and does not extend to any other portion of
this final rule. Further, by correcting this unintentional error, EPA
is not reopening any issues from the December 2025 Final Rule or the
associated IFR from July of 2025.
IV. Significant Comments and Changes Since Proposal for NSPS OOOOb and
EG OOOOc (January 2025 Proposal)
This section of the preamble presents in each subsection a detailed
summary of the significant comments received on, and changes made,
since the January 2025 Proposal for the topic addressed in that
subsection. This final action does not address or take any position on
the best system of emission reduction (BSER) analysis included in the
March 2024 Final Rule record which the EPA used to support promulgation
of the standards included in NSPS OOOOb and the presumptive standards
included in EG OOOOc.
[[Page 18066]]
The EPA's full response to comments on the January 2025 Proposal,
including any comments not discussed in this preamble, is available in
the EPA's Response to Comment (RTC) document for this final rule.\51\
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\51\ Reconsideration of 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 January 2025 Proposed Rule (90 FR
3734; January 15, 2025). Included in Docket ID EPA-HQ-OAR-2024-0358.
---------------------------------------------------------------------------
A. Temporary Flaring Provisions for Associated Gas in Certain
Situations
For oil wells that are not routinely flaring (i.e., wells that
route associated gas to sales lines or an equivalent alternative), the
March 2024 Final Rule allowed owners and operators to route associated
gas to a flare or control device in certain situations for 24 hours.
These situations include times when there is a need to flare due to
malfunctions, including for safety reasons. Further, these situations
may include repair, maintenance (including blowdowns), bradenhead test,
packer leakage test, production test, or commissioning. As stated in
the January 2025 Proposal, industry petitioners seeking reconsideration
claimed that the 24-hour limitation for temporary flaring is not
sufficient for malfunctions, including for reasons of safety, and/or
for repair and maintenance. Additionally, they claimed well sites may
not be accessible during weather events (i.e., winter storms), which
are a significant factor for temporary flaring that lasts for more than
24 hours. Industry petitioners maintained that a 72-hour timeframe is
more appropriate for temporary flaring due to the unique
characteristics of each wellsite, weather conditions, or a combination
of both. In the January 2025 Proposal, the EPA proposed to allow 48
hours for temporary flaring based on submitted industry data. The EPA
agreed that the data showed that 24 hours was insufficient to resolve
all malfunction, maintenance, and repair events. In the January 2025
proposal, the EPA also solicited comments on allowing owners and
operators of associated gas affected facilities to route to a flare or
control device for up to 72 hours if exigent circumstances exist, since
the industry indicated that some events last for more than 48 hours. In
particular, the EPA solicited comments on whether there are other
specific exigent circumstances for which the EPA should consider
allowing an owner or operator to route to a flare or control device
beyond the proposed 48-hour allowance for repairs and malfunctions.
Furthermore, the EPA solicited comments on recordkeeping and reporting
requirements if the EPA were to include an allowance for owners or
operators of associated gas affected facilities to route to a flare or
control device for up to 72 hours for exigent circumstances.
The EPA received several comments on this aspect of the January
2025 Proposal. The EPA received comments on exigent circumstances, the
temporary flaring timeframe, and recordkeeping and reporting
requirements. These comments and the EPA's responses are provided in
sections IV.A.1 through 4 of this preamble. The EPA also received
comments requesting alternative exemptions and cutoffs to limit
temporary flaring. These comments and the EPA's responses are provided
in section IV.A.5 of this preamble. The EPA's full response to comments
on the January 2025 Proposal, including any comments not discussed in
this preamble, is available in the EPA's RTC document for the final
rule.
1. Exigent Circumstances
In the January 2025 Proposal, the EPA solicited comment on allowing
owners or operators of associated gas affected facilities to
temporarily route the associated gas to a flare or control device for
up to 72 hours in certain situations if exigent circumstances exist.
Such exigent circumstances would include situations where an owner or
operator cannot physically access a site due to weather or other
conditions (e.g., road closures). In addition to extreme weather events
and road closures, the EPA solicited comment on whether there are other
specific exigent circumstances for which the EPA should consider
allowing an owner or operator to route to a flare or control device
beyond the proposed 48-hour allowance for repairs and malfunctions. The
EPA received several comments on this aspect of the January 2025
Proposal. These comments and the EPA responses are provided in this
section of the preamble.
Comment: Several commenters requested that the EPA include other
exigent circumstances in addition to those proposed. One commenter
requested that the EPA clarify that exigent circumstances include, but
are not limited to, flooding, road washouts, fires and explosions,
personnel shortages due to illness or labor disputes, wildfires,
earthquakes, hazmat emergencies, evacuation orders, war or civil
unrest, and equipment supply chain issues.\52\
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\52\ Document ID No. EPA-HQ-OAR-2024-0358-0082.
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Another commenter \53\ noted that, as stated in previous comments
they submitted on the December 2022 Supplemental Proposal,\54\ it is
often necessary to temporarily route gas to control devices for safety
and/or operational purposes in situations when associated gas could not
be routed to a sales line or used for other beneficial purposes. The
commenter requested that the EPA provide additional flexibility to
allow temporary routing of gas to control devices when other exigent
circumstances exist, including, but not limited to, interruption in
service, extreme weather events, and road closures that prevent access
to sites. The commenter stated that the January 2025 Proposal cites an
API survey that concluded the average duration for temporary flaring
was 46 hours per event. While the changes in the January 2025 Proposal
to allow temporary flaring from 24 to 48 hours might accommodate the
average temporary flaring event determined in the study, the commenter
urged the EPA to consider allowing temporary flaring of 72 hours or
more to account for the varying configurations of well sites and
exigent circumstances.
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\53\ Document ID No. EPA-HQ-OAR-2024-0358-0085.
\54\ Docket ID No. EPA-HQ-OAR-2021-0317.
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Consistent with the previous comment, another commenter noted that
the EPA requested input on other exigent circumstances that warrant
flaring beyond 48 hours.\55\ The commenter listed inclement weather,
site access, operations outside normal business hours, availability of
service providers and equipment, safety of operator personnel or the
public, and repair, maintenance, production testing, or commissioning
as exigent circumstances warranting longer flaring times. However, the
commenter recommended that the EPA allow other scenarios when 72 hours
of flaring would result in lower emissions than the alternative, e.g.,
shutting down a facility requiring blowdowns that vent emissions to the
atmosphere resulting in greater emissions as compared to those from
flaring. As such, the commenter requested that the EPA consider all
exigent circumstances to include situations where the alternative
operation would result in more emissions, rather than allowing flaring
for 72 hours.
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\55\ Document ID No. EPA-HQ-OAR-2024-0358-0095.
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Response: As noted in section III.A.4 of the January 2025 Proposal
(Basis for Proposed Changes), the EPA acknowledges that there are
special
[[Page 18067]]
situations where a longer timeframe than proposed may be needed and
such circumstances may be beyond the owner's and operator's control.
While the EPA agrees with some commenters that other exigent
circumstances should be included in addition to extreme weather events
and road closures, not every situation suggested by commenters
qualifies as an exigent circumstance. As explained in section III.A of
this preamble, the events that qualify for the exigent circumstances
extension should be severe in nature and have a direct impact on the
owner's or operator's ability to physically access the site with the
necessary equipment and personnel to address the equipment malfunction
incident which caused the need to temporarily flare. For instances
where there is a need to flare beyond 72 hours due to an unexpected
malfunction event and equipment and/or personnel are not readily
available due to supply chain issues and/or temporary personnel
shortages due to reasons beyond an owner's or operator's control, the
EPA agrees that allowing an owner or operator to flare beyond 72 hours
meets EPA's intent of what is considered an ``exigent circumstance''
and we revised the final rule to specifically allow flaring beyond 72
hours for such instances. While the EPA acknowledges that there may be
instances when extraordinary circumstances, such as a national pandemic
which is beyond an owner's or operator's control, could result in a
temporary shortage of personnel being available to resolve an
unexpected malfunction or to access a facility within 72 hours of an
event, we do not consider personnel shortages due to illness or labor
disputes to qualify as exigent circumstances. Personnel shortages due
to illness or labor disputes are best characterized as an internal
operational matter for which the owner or operator holds primary
responsibility and is expected to manage through appropriate
contingency planning.
To address commenters' concerns, the final rule defines an
``exigent circumstance'' to be a situation that results in the
inability to reasonably access a site with the necessary equipment and
personnel to address and resolve incidents that cause the need to
temporarily flare associated gas for more than 72 hours. This includes
circumstances where there is a need to flare beyond 72 hours due to an
unexpected malfunction event and equipment needed to resolve an
incident are not readily available due to an owner's or operator's
inability to secure the required equipment for reasons beyond an
owner's or operator's control (i.e., supply chain issues); or there is
a temporary shortage of personnel needed to resolve an incident due to
a circumstance such as a declared national pandemic that is beyond an
owner's or operator's control.
To address a commenter's request that we allow flaring for exigent
circumstances to include situations where an alternative operation
would result in more emissions rather than allowing flaring for 72
hours, we revised the final rule to allow flaring for up to 72 hours
and beyond 72 hours for exigent circumstances, reducing the need for
well shut ins.
In this final action, we are revising the March 2024 Final Rule to
allow temporary flaring of associated gas for up to 72 hours for
situations where the owner or operator cannot comply with the standard
due to malfunctions, including reasons for safety, repairs, and
maintenance. For exigent circumstances, an owner or operator can
temporarily route to a flare or control device for durations over 72
hours until an exigent circumstance is no longer present. Following the
new temporary flaring timeframe extension and clarification of what
constitutes an exigent circumstance as stated in section III.A of this
preamble, we disagree that some of the events listed by commenters
(operations outside normal business hours, availability of service or
equipment, safety of the operator or the public, and activities like
repair, maintenance, production testing, or commissioning) on their own
qualify as exigent circumstances. In these instances, an owner or
operator will have up to 72 hours to resolve equipment malfunctions,
which is in line with what the commenter requested. However, we also
acknowledge that some of these situations may fall under an exigent
circumstance if the necessary equipment and personnel are not available
to resolve a malfunction incident within a 72 hour timeframe due to
circumstances that are beyond an owner's or operator's control, or
access to a site is restricted due to worker safety (e.g., if traveling
to the site is unreasonably dangerous due to a wildfire). After
invoking exigent circumstances, flaring can continue until the
equipment malfunction incident is resolved. However, this must be no
longer than 72 hours after the site can be accessed, and the necessary
equipment and personnel are obtained (72 hours after the exigent
circumstances which prevented access and equipment malfunction repair
are no longer present).
2. Allowance for Temporary Flaring of 72 Hours or More
In the January 2025 Proposal, the EPA proposed extending the
allowable time for temporary flaring of associated gas during
malfunctions, including for reasons of safety and during repair and
maintenance. The proposed allowable timeframe was 48 hours, an increase
from 24 hours in the March 2024 Final Rule. In response, several
commenters requested that the EPA further extend the temporary flaring
allowance to 72 hours. These commenters argued that a longer duration
would better reflect field conditions, particularly in areas where
access to equipment or personnel is delayed due to weather, geography,
or other logistical barriers. They stated that even with proactive
planning, certain malfunctions or maintenance activities may require
more than 48 hours to resolve. The commenters also noted that forcing
operators to end flaring before the issue is resolved could create
safety risks or lead to unnecessary equipment shutdowns.
Other commenters disagreed and urged the EPA to retain the original
24-hour limit or allow for extensions only when operators clearly
justify the need based on specific facts. They expressed concern that a
blanket 72-hour window could weaken enforcement and lead to longer
periods of uncontrolled emissions. They emphasized the need for clear
limits to ensure that temporary flaring remains a last resort and is
used only when necessary. The API data submitted to the EPA along with
information from other stakeholders \56\ show a range of flaring
durations, with a notable percentage of events exceeding both 24 and 72
hours. These data suggest that while an extended flaring duration is
not the norm, it does occur with some regularity, especially in cases
involving equipment failure, inclement weather conditions and/or
limited site access. Several comments were received on this aspect of
the January 2025 Proposal. These comments and EPA's responses are
provided in this section of the preamble.
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\56\ Docket ID No. EPA-HQ-OAR-2024-0358.
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Comment: One commenter \57\ appreciated the EPA's acknowledgment
that a 24-hour limit on temporary flaring during situations they
describe as ``Critical Circumstances'' (e.g., due to a malfunction or
incident that endangers the safety of operator personnel or the public
or during repair and maintenance
[[Page 18068]]
activities) is often infeasible and warrants additional time,
particularly for remote, unmanned sites in areas prone to extreme
weather events and poor road conditions.\58\ However, they expressed
that they do not believe that the proposed 48-hour allowance will allow
sufficient time to fix the problem and return the site to normal
operations such that temporary flaring can stop during many ``critical
circumstances.'' The commenter suggested that a 72-hour temporary
flaring duration would provide sufficient time to respond to,
troubleshoot, and repair equipment during most, but not all, ``critical
circumstances'' in areas where extreme weather and road conditions are
frequent, such as during the winter months in North Dakota.\59\
Further, the commenter added that these repairs are often dangerous to
undertake due to the extreme weather in, for example, North Dakota's
Williston Basin. For instance, the commenter reported that on February
10th, 2025, the National Weather Service issued an Extreme Cold Warning
in the majority of counties in North Dakota, advising that ``life
threatening wind chills as low as 55 below zero could cause frostbite
on exposed skin in as little as 5 minutes.'' \60\ The National Weather
Service also advised to take precautions ``if you must go outside.''
\61\ The commenter stated that requiring operators to undertake
immediate repair work in these conditions can unnecessarily put them in
harm's way. For those ``critical circumstances'' that would otherwise
require longer than 72 hours, the commenter noted that operators ``must
innovate and improve their maintenance, response, and repair practices
to meet what would remain a challenging deadline in many instances.''
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\57\ Document ID No. EPA-HQ-OAR-2024-0358-0092.
\58\ The EPA notes that while the commenter uses the term
``Critical Circumstances,'' we interpret this to mean ``exigent
circumstances.''
\59\ To date, Hess (the commenter) has provided the EPA with
extensive documentation of circumstances affecting its Williston
Basin production operations that necessitate up to 72-hours for
temporary flaring in these circumstances. See November Hess
Presentation; Hess Corporation, Hess Briefing for EPA: Oil and
Natural Gas Final Methane Rule NSPS OOOOb and EG OOOOc, EPA-HQ-OAR-
2024-0358-0020 (Feb. 29, 2024) (``February Hess Presentation'');
Hess Corporation, Hess Briefing for EPA: NSPS OOOOb Safety,
Malfunction & Repair Temporary Flaring Allowance, EPA-HQ-OAR-2024-
0358-0031 (June 3, 2024) (``June Hess Presentation''); Hess
Corporation, McKenzie County Frost Restrictions, EPA-HQ-OAR-2024-
0358-0037 (July 19, 2024); Hess Corporation, Examples of North
Dakota Road Closures and Restrictions, EPA-HQ-OAR-2024-0358-0037
(July 19, 2024); Hess Corporation, Hess E.O. 12866 Meeting with OMB/
OIRA: Oil and Natural Gas NSPS OOOOb and EG OOOOc Reconsideration
Proposal, 13, EPA-HQ-OAR-2024-0358-0038-0046 (Nov. 7, 2024)
(``November Hess Presentation'').
\60\ National Weather Service, NWS Alerts, <a href="https://alerts.weather.gov/search?history=1&zone=NDZ009">https://alerts.weather.gov/search?history=1&zone=NDZ009</a> (last visited Feb.
28, 2025).
\61\ Id.
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The same commenter provided that, in the January 2025 Proposal, the
EPA cited survey data provided by API (the ``Temporary Flaring
Survey'') to support extending the temporary flaring allowance up to 48
hours.\62\ The EPA proposed extending the temporary flaring allowance
from 24 to 48 hours in the January 2025 Proposal based on the Temporary
Flaring Survey's average flaring duration time of 46 hours. In doing
so, the commenter asserted that the EPA ignored that the data shows the
average flaring duration is not uniform across basins. According to the
commenter, both the Temporary Flaring Survey and the commenter's own
data \63\ demonstrate that the widely dispersed facilities and extreme
winter weather conditions in the Williston Basin (North Dakota and
Montana) can necessitate longer temporary flaring for responding to
``Critical Circumstances'' other than warmer and more easily accessed
basins, like the Permian Basin (Texas and New Mexico). They highlighted
that the Temporary Flaring Survey data shows that Williston Basin
flaring incidents exceeded 72 hours in 78 percent of the reported data,
compared to just 11 percent in the Permian Basin.\64\ For the Permian
Basin, they highlighted that 12 percent of flaring events exceeded 24
hours, claiming that where flaring exceeded 24 hours, it is extremely
probable the flaring continued beyond 72 hours. The commenter reported
that its extensive temporary flaring data (e.g., Temporary Flaring
Survey) shows that an average of approximately 72 hours of temporary
flaring is necessary during their ``Critical Circumstances.'' The
commenter asserted that the data and information provided by both API
and Hess suggest that a 72-hour temporary flaring duration allowance is
an appropriate default for a nationwide rule.\65\
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\62\ See American Petroleum Institute, Operator Survey:
Temporary Flaring, 4, EPA-HQ-OAR-2024-0358-0038 (July 2024)
(``Temporary Flaring Survey'').
\63\ Hess's operations in the Bakken formation span roughly
7,200 square miles and include many unmanned sites. Hess provided
information demonstrating that it often cannot physically access a
site within 48 hours, and seasonal conditions and extreme weather
events may delay accessibility for days and up to over a week until
access roads to a wellsite are passable. See November Hess
Presentation at 10.
\64\ Temporary Flaring Survey at 6.
\65\ See Hess Corporation, Hess E.O. 12866 Meeting with OMB/
OIRA: Oil and Natural Gas NSPS OOOOb and EG OOOOc Reconsideration
Proposal, 13, EPA-HQ-OAR-2024-0358-0046 (Nov. 7, 2024) (``November
Hess Presentation'').
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The commenter added that it provided temporary flaring data that
reflected events that it had identified internally as the highest
priority of work (``break-in work'').\66\ The commenter explained that
this is the priority given to ``Critical Circumstance'' responses. The
commenter added that its sites are often not accessible within 24 hours
due to difficult terrain, long travel distances between facilities, and
extreme weather. These conditions are an impediment to the first step
in response: travelling to the facility to investigate the cause of the
``Critical Circumstance.'' The commenter added that its data show the
average response time from notification creation to resolution was
slightly more than 72 hours; however, as an average implies, many
events lasted longer than 72 hours. The commenter contended that its
data demonstrate that 48 hours is often not long enough to travel to
the facility, troubleshoot, obtain necessary equipment, and complete
repair, even with normal business processes that incorporate
efficiencies.\67\ The commenter asserted that the EPA's proposed 48-
hour limit inappropriately relied on a summary report from New Mexico
and from a Colorado regulation to assert that a 48-hour period is
sufficient for temporary flaring for malfunction/safety and repair/
maintenance situations. However, the commenter noted that areas such as
North Dakota are subject to more frequent and more extreme weather
events than those areas.
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\66\ Hess's ``highest priority notifications'' response system
prioritizes repair work that can result in temporary flaring above
previously scheduled work. Hess provided the EPA with data showing
that the average notification creation to resolution cycle times
between 2020 and 2024 averaged 3.2 days. See June Hess Presentation
at 12.
\67\ Under Hess's ``highest priority notifications'' response
system, it can still sometimes take up to 21 hours for an operator
to access the facility and identify the problem necessitating the
temporary flaring. If a maintenance crew is required for repair, it
can take multiple days even with equipment available. See June Hess
Presentation at 12.
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In addition, the commenter explained that oil and gas facilities in
North Dakota are spread across expansive and geographically remote
locations.\68\ The commenter expressed that it does not believe it is
appropriate to finalize a one-size-fits-all approach based on these two
unique States (i.e., Colorado and New Mexico). Moreover, the commenter
reiterated that the Permian Basin data in the Temporary Flaring Survey
shows that where flaring exceeded 24 hours, it
[[Page 18069]]
is extremely probable that flaring exceeded 72 hours. In conclusion,
the commenter argued that a blanket 72-hour temporary flaring allowance
for ``Critical Circumstances'' provides a more reasonable timeframe and
will force operator innovation.
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\68\ See Hess Corporation, Hess' Bakken Operating Area, EPA-HQ-
OAR-2024-0358-0038-0037_attachment 1 (July 19, 2024).
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Conversely, another commenter urged the EPA not to allow operators
to temporarily route associated gas to a flare or control device for up
to 72 hours for weather-related delays.\69\ The commenter did not
support any additional allowances for temporary flaring for up to 72
hours. In the commenter's opinion, the Temporary Flaring Survey does
not support the need for a 72-hour allowance for weather-related
delays. The commenter reported that only three percent of the total
data demonstrated that inclement weather was the cause of needing time
to mitigate flaring with an average duration of 21 hours of temporary
flaring per event.
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\69\ Document ID No. EPA-HQ-OAR-2024-0358-0096.
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The commenter also pointed to the Temporary Flaring Survey data on
reportable emission events from the 2021 winter storm Uri that impacted
Texas.\70\ The data includes all reportable emission events the Texas
Commission on Environmental Quality (TCEQ) received from all industry
sectors in the State. The commenter expressed that it is vital that the
EPA examines this data in more detail before moving forward with any
extension of temporary flaring duration based on weather. The commenter
highlighted that the TCEQ dataset includes 328 emission events, but 78
percent of those events occurred at facilities that are not upstream
oil and gas facilities and argued that those events are therefore not
relevant to any decision to allow for extended flaring due to inclement
weather.
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\70\ See API, Document ID No. EPA-HQ-OAR-2024-0358-0038,
attachment 6.
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Response: The EPA appreciates the information and insights provided
by commenters and agrees overall with the recommendations for extending
the temporary flaring allowance to 72 hours. We agree with the
commenters that the proposed 48-hour temporary flaring limit, while
directionally helpful, does not adequately address the logistical
complexities present in the widely dispersed locations in the oil and
gas industry. Allowing for up to 72 hours promotes administrability and
equitable treatment among sites for the vast majority of flaring
incidents discussed in this preamble, while also providing for
emissions reductions in tandem with the requirement that sources stop
flaring as soon as the qualifying incident is resolved. Compliance with
these requirements will be reported to the EPA and enforced through a
combination of new (finalized in this rule) and preexisting (from the
2024 rule) emissions-reporting obligations, and many facilities have an
independent economic incentive to cease unnecessary flaring where the
gas could otherwise be captured and sold.
The Temporary Flaring Survey indicates that more than 17 percent of
flaring events required more than 24 hours of temporary flaring of
associated gas per event, and more than 15 percent of flaring events
required more than 72 hours of temporary flaring per event. The causes
of these extended flaring durations were multifaceted and included
inclement weather, primarily in the Williston Basin which routinely
faces harsh winter weather conditions, and other factors such as the
unique characteristics of each wellsite (unmanned, remote, and
dispersed).
Critically, weather is not the only contributor to extended flaring
events, as demonstrated in the dataset and comments provided by
petitioners. Information gathered from industry meetings and the
Temporary Flaring Survey indicate that these logistical challenges
exist regardless of weather and are often intensified by routine
operational hurdles such as scheduling contractor support, transporting
heavy equipment, and adhering to internal safety procedures. Further
analysis reveals the Temporary Flaring Survey reported 86 flaring
events as weather-impacted events, and the survey classified over 600
flaring events as ``[u]nknown.'' While we do not know the cause of the
need to flare for the over 600 flaring events in the Temporary Flaring
Survey, maintaining a 24-hour, or even 48-hour, flaring timeframe based
on the percentage of reported inclement weather-impacted events
presents a narrow reading of the data and does not reflect the
``[u]nknown'' flaring events that exhibited the highest flaring
durations and standard deviations. The commenter's argument centers on
a narrow interpretation of weather-related flaring events that
indicates that only three percent of total incidents in the Temporary
Flaring Survey cite weather as the cause for the need to flare and that
those averaged 21 hours per event.\71\ While it is true that the
Temporary Flaring Survey indicates that flaring events often can be
resolved quickly, the data and information provided by industry also
indicate that other factors can impact an owner's or operator's ability
to limit the duration of flaring that are beyond their control. In
instances where an owner or operator is able to limit the duration of
flaring by addressing the cause of the need for flaring in a timely
manner, an owner or operator is encouraged to limit the flaring
duration to the maximum extent possible. The EPA is extending the
flaring allowance based on the ability of an owner or operator to
access their flaring event site and resolve the cause of the need to
flare. As noted previously, while weather can be a contributing factor
affecting access to a site, it is not the only potential reason
limiting access to a site. As such, the EPA has extended the allowance
to flare up to 72 hours in absence of an exigent circumstance and
allows more than 72 hours in instances where an owner or operator makes
a legitimate exigent circumstance claim that limits their ability to
access and resolve the cause for a flaring event within 72 hours. This
extended timeframe gives owners and operators enough time to travel to
facilities (including geographically remote facilities), troubleshoot,
obtain necessary equipment, and complete repairs. It also provides
sufficient time to overcome many inclement weather situations. This
extended timeframe, coupled with the ability to claim exigent
circumstances for even more time, should limit or eliminate the need to
shut-in operations in situations of temporary flaring for malfunction,
safety, or maintenance.
---------------------------------------------------------------------------
\71\ Document ID No. EPA-HQ-OAR-2024-0358-0096.
---------------------------------------------------------------------------
Additionally, the Temporary Flaring Survey shows regional variation
in flaring durations, as a commenter notes. For instance, 78 percent of
flaring incidents in the Williston Basin exceeded 72 hours, compared to
just 11 percent in the Permian Basin. This variation highlights that a
rigid one-size-fits-all approach based exclusively on national
averages, and which does not allow for any flexibility, does not
account for critical differences in field conditions, wellsite
uniqueness, or operational complexity. The data confirm that events
where flaring exceeds 24 hours often continue well beyond 72 hours. As
such, setting the upper limit at 72 hours with the possibility of
additional time for exigent circumstances better aligns with field
data, while still placing expectations on owners and operators to
promptly resolve issues.
As explained in sections IV.A.4 (Support for a 24-hour Allowance
for Temporary Flaring) and IV.A.5 (Consideration of Additional
[[Page 18070]]
Limitations and Targeted Exceptions to Temporary Flaring) of this
preamble, the EPA considered but did not adopt several approaches
raised by petitioners and public comments on the proposal, including a
24-hour or 48-hour flaring allowance and additional temporary flaring
limits or targeted geographical exceptions.
3. Recordkeeping and Reporting
In the proposed rule, the EPA also solicited comment on the
recordkeeping and reporting requirements if the Agency were to include
an allowance for owners or operators of associated gas affected
facilities to route to a flare or control device for up to 72 hours for
``exigent circumstances.'' \72\ The topics of exigent circumstances and
temporary flaring duration are discussed more in section IV.A.1 and
IV.A.2 of this preamble respectively. Specifically, we solicited
comment on requiring an owner or operator who must make use of the
extended timeframe to maintain records that include a written
description of the exigent circumstance, the rationale for the need to
route to a flare or control device beyond the default allowable
timeline, a description of the measures taken to minimize temporary
flaring/routing to a control device, and the duration of temporary
flaring/routing to a control device due to the identified exigent
circumstance. Lastly, we solicited comment on requiring an owner or
operator to include a summary of their exigent circumstance recorded
events in their annual report.
---------------------------------------------------------------------------
\72\ 90 FR 3740-41 (January 15, 2025).
---------------------------------------------------------------------------
The EPA received two groups of comments about recordkeeping and
reporting requirements for exigent circumstances. Support for
recordkeeping and reporting came from environmental groups, who argued
that these requirements are important for accountability, ensuring the
flaring event was an appropriate action, and encouraging owners and
operators to limit flare durations. Industry commenters opposed this
proposed requirement. They argued that extending recordkeeping and
reporting requirements for exigent circumstances would not provide any
environmental benefit and would not expedite the repair or maintenance
process. Industry commenters further asserted that having additional
recordkeeping and reporting provisions would add unnecessary burden to
owners and operators at a time when they should prioritize resources to
address the emergency or maintenance event.
Based on comments received and EPA's decision to broaden what
constitutes an ``exigent circumstance'' to include instances where the
necessary equipment and/or personnel are not available to conduct the
necessary repairs for reasons beyond an owner's or operator's control,
the EPA is finalizing the following recordkeeping and reporting
requirements when an exigent circumstance is invoked: a written
description of the ``exigent circumstance'' requiring the need to flare
or route to a control device beyond 72 hours; a description of the
steps taken to resolve the need for temporary flaring/routing to a
control device; the dates and times an identified ``exigent
circumstance'' started and ended (e.g., when owners or operators are
able to access site, when personnel and/or equipment are available) and
the total duration of each ``exigent circumstance''; and the dates and
times temporary flaring/routing to a control device started and ended
and the total duration of temporary flaring/routing to a control device
due to the identified ``exigent circumstance.'' We require owners and
operators to report this information in their annual report. See
section IV.A.1 of this preamble for comments received on exigent
circumstances and EPA's response to those comments.
As mentioned above, we received several comments on this aspect of
the January 2025 Proposal. These comments and the EPA responses are
provided in this section of the preamble.
Comment: Several industry commenters did not support the EPA
requiring records and reporting (in annual reports) of information
regarding exigent circumstances necessitating temporary flaring beyond
the default time allowance. One commenter \73\ stated that operators
should focus on resolving emergencies and/or maintenance issues that
arise to reduce and/or remove the need to flare, instead of
recordkeeping and reporting requirements that provide no environmental
benefit.\74\ Additionally, according to the commenter, such
recordkeeping and reporting causes burden for the operator and the EPA.
The commenter requested that the EPA implement a blanket timeframe of
at least 72 hours for temporary flaring without the need for
recordkeeping and reporting such events.
---------------------------------------------------------------------------
\74\ Document ID No. EPA-HQ-OAR-2024-0358-0095.
---------------------------------------------------------------------------
Similarly, one commenter \75\ noted that the additional
administrative recordkeeping and reporting burden to conduct, document,
and report an exigent circumstance would not provide a corresponding
environmental benefit.\76\ The commenter stated that the NSPS OOOOb and
EG OOOOc rules already require recordkeeping and reporting for
temporary flaring events that are sufficient to provide transparency
into operators' temporary associated gas flaring activities.
---------------------------------------------------------------------------
\76\ Document ID No. EPA-HQ-OAR-2024-0358-0092.
---------------------------------------------------------------------------
Another commenter expressed concern about the documentation
required for exigent circumstances, stating that it is unnecessary and
unduly burdensome as a blanket 72-hour allowance is warranted.\77\
---------------------------------------------------------------------------
\77\ Document ID No. EPA-HQ-OAR-2024-0358-0088.
---------------------------------------------------------------------------
Conversely, another commenter expressed that if the EPA finalizes a
nationwide exception for exigent circumstances, then the EPA must add
specific recordkeeping and reporting requirements to the rule.\78\ The
commenter supported the recordkeeping and reporting that the EPA listed
in the proposal as a minimum requirement to document and justify any
temporary flaring or routing to control devices that goes beyond the
baseline limit. The commenter asked that this documentation include a
description of the circumstance requiring extended flaring, the
rationale for routing to a flare or control device beyond the allowed
limit, documentation from public information that supports the claim
that extended flaring was necessary (e.g., traffic information showing
road closures), a description of the measures taken to minimize
temporary flaring, and the duration of temporary flaring. Also, the
commenter requested that the annual report require a summary of the
number, cause, and duration of extended flaring events.
---------------------------------------------------------------------------
\78\ Document ID No. EPA-HQ-OAR-2024-0358-0096.
---------------------------------------------------------------------------
Response: The EPA agrees that the near-term focus of owners and
operators in these situations should be on the immediate need of
resolving emergencies and/or maintenance issues as quickly as possible
to mitigate the need to flare. However, we disagree that recordkeeping
and reporting is unnecessary and that any such requirements will cause
undue burden to the owners and operators. First, base-level
recordkeeping and reporting requirements already exist for owners and
operators in the regulations (40 CFR 60.5420b(b)(4)(i) and (2) and
(c)(3) (i) and (ii); and 40 CFR 60.5420c(b)(3)(i) and (ii) and
(c)(2)(i) and (ii)) for all temporary flaring that are not at issue in
this rulemaking. Including exigent circumstance recordkeeping and
[[Page 18071]]
reporting only adds additional requirements when an exigent
circumstance occurs. Thus, if the exigent circumstance provision is not
invoked, owners and operators are not required to complete any
additional recordkeeping and reporting beyond the base-level
requirements for all temporary flaring situations. The additional
information that we will collect for exigent circumstances does not
duplicate the base-level recordkeeping requirements included in the
March 2024 Final Rule and is not time-consuming or resource intensive.
Second, requiring additional recordkeeping and reporting for
exigent circumstances documents compliance with the allowance for
temporary flaring beyond 72 hours for exigent circumstances.
Specifically, the additional recordkeeping and reporting requirements
only apply when an owner or operator invokes an extension of flaring
duration due to an exigent circumstance and only includes minimal
documentation to ensure that owners and operators are properly invoking
and implementing the flaring extension.
Lastly, in response to comments that claim that owners and
operators should first focus on returning the site to normal
operations, the EPA agrees. The recordkeeping requirements included in
the final amendments can be completed after the owner or operator
addresses the underlying issue that gave rise to the need for temporary
flaring. None of the recordkeeping requirements mandate action
contemporaneous with conducting repair or maintenance. The
recordkeeping can occur after repair or maintenance but should happen
relatively close in time so that the owner or operator can record
accurate information.
4. Support for a 24-Hour Allowance for Temporary Flaring
Following the January 2025 Proposal, several industry
representatives and State agency commenters recommended extending the
temporary flaring allowance to 72 hours. In contrast, other commenters,
including environmental organizations and private citizens, urged the
EPA to retain the original 24-hour limit from the March 2024 Final
Rule, with limited allowances for extensions up to 48 hours in exigent
circumstances or until the event is resolved. As part of the proposed
rule, the EPA requested data and feedback on whether the revised
flaring duration could potentially increase primary or secondary
emissions and invited additional information to either substantiate the
proposed 48-hour allowance or justify maintaining the 24-hour duration
in the March 2024 Final Rule.
The EPA received several comments on this aspect of the January
2025 Proposal. These comments and the EPA's responses are provided in
this section of the preamble.
Comment: Two commenters requested that the EPA retain the 24-hour
allowance for temporary flaring.\79\ One commenter disagreed with the
EPA's determination that the information provided in the Temporary
Flaring Survey supports allowing temporary flaring for up to 48 hours
during malfunctions but believes the information provided in the
Temporary Flaring Survey supports retaining the 24-hour allowance,
potentially with limited exceptions.\80\ The commenter agreed with the
EPA's statement that the Temporary Flaring Survey supports an
expectation ``that owners and operators can feasibly limit temporary
flaring to less than 24 hours in a large majority of situations.'' \81\
The commenter stated that the Temporary Flaring Survey had 2,804
instances of temporary flaring of associated gas at sites in the San
Joaquin, Permian, and Williston Basins.\82\ According to the U.S.
Energy Information Administration (EIA), the primary producers of
associated gas in the U.S. are the Permian, Bakken, Eagle Ford,
Anadarko, and Niobrara Basins.\83\ The commenter observed that the
Temporary Flaring Survey did not include any information on temporary
flaring in the other three basins identified by the EIA. For the EPA to
justify a nationwide change, the commenter contended that the agency
should examine data from all basins where associated gas is primarily
produced (and thus has the greatest potential for a need to temporarily
route to a flare or control device) to determine whether the current
allowance of 24 hours is appropriate. According to the commenter, the
Temporary Flaring Survey does not support the EPA's proposed change to
allow up to 48 hours for temporary flaring of associated gas, and data
from other basins may also further demonstrate this change is not
justified. The commenter asserted that the Temporary Flaring Survey
therefore is not complete enough to justify an alteration of the
standard for the entire country.
---------------------------------------------------------------------------
\79\ Document ID Nos. EPA-HQ-OAR-2024-0358-0080, EPA-HQ-OAR-
2024-0358-0096.
\80\ Document ID No. EPA-HQ-OAR-2024-0358-0096.
\81\ 90 FR at 3740 (January 15, 2025).
\82\ See API, Document ID. No. EPA-HQ-OAR-2024-0358-003,
attachment 3.
\83\ U.S. EIA, ``U.S. associated gas production increased nearly
8% in 2023.'' November 13, 2024. <a href="https://www.eia.gov/todayinenergy/detail.php?id=63704#">https://www.eia.gov/todayinenergy/detail.php?id=63704#</a>.
---------------------------------------------------------------------------
Additionally, the commenter stated that an analysis of the
Temporary Flaring Survey shows the average duration of temporary
flaring of associated gas is 46 hours, which the EPA used as the basis
for its proposal. However, they reported that a detailed examination of
this data does not support a blanket allowance of 48 hours.\84\ The
commenter noted that most of the data come from the Permian Basin
(2,581, or 92 percent) and show that the average duration of temporary
flaring was 26 hours, with 318 instances requiring greater than 24
hours (12 percent of the total instances for this basin). Nearly 75
percent of the instances (1,930) are labeled as ``high priority,'' and
the average duration of temporary flaring for these events was five
hours, with only 14 instances greater than 24 hours (0.7 percent). In
the commenter's opinion, this demonstrates that operators can address
issues, such as maintenance and safety concerns, leading to temporary
flaring well within the currently allowed 24-hour duration for sites in
the Permian Basin.
---------------------------------------------------------------------------
\84\ See Attachments A and B of the commenter's letter.
---------------------------------------------------------------------------
The commenter further observed that the 46-hour average duration in
the Temporary Flaring Survey is skewed by data from the Williston
Basin, representing only 166 total instances, or just six percent, of
the Temporary Flaring Survey data. The commenter reported that the
average duration of temporary flaring for these instances is 378 hours.
Additional details provided by Hess, and within the Temporary Flaring
Survey data, show that separator backpressure valve issues dominate as
the cause of temporary flaring (89 percent of instances for the
Williston Basin), and inclement weather is only listed as an issue for
10 instances, which have an average duration of 125 hours for temporary
flaring. The commenter provided that additional information from Hess
specifies these backpressure valve issues are unscheduled maintenance
or malfunctions due to separator backpressure valve issues, but it is
not clear whether these issues are preventable. The commenter asserted
that this outlier data for the Willison Basin does not justify a
blanket 48-hour nationwide allowance.
The commenter also noted that the Temporary Flaring Survey includes
a total of 57 instances from the San Joaquin Basin, which is not one of
the
[[Page 18072]]
primary producers of associated gas. Moreover, the commenter indicated
that the data for this basin demonstrate an ability to return to normal
operations (i.e., stop flaring of associated gas) after eight hours on
average, with only four instances requiring more than 24 hours. The
commenter pointed out that of those four instances exceeding 24 hours,
three are labeled as ``high priority'' and the cause is listed as power
failure (two instances), compressor failure (one instance), and valve
failure (one instance). While these limited exceptions do exist, the
commenter suggested that the overall data from the San Joaquin Basin
further support the position that the EPA should retain the 24-hour
allowance.
Also, the commenter evaluated data from New Mexico exploration and
production operators, which the commenter claimed demonstrate that
operators can comply with a 24-hour limit on temporary flaring during
malfunctions or incidents that endanger the safety of operator
personnel or the public, as well as during repair and maintenance
activities.
The commenter argued that New Mexico requires exploration and
production operators (``upstream operators'') to report flaring or
venting of natural gas on form C-129 ``that exceeds 50 thousand cubic
feet (MCF) in volume and either results from an emergency or
malfunction, or lasts eight hours or more cumulatively within any 24-
hour period from a single event.'' \85\ The report must include the
time of venting or flaring and the nature and cause of the venting or
flaring.\86\
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\85\ N.M. Admin. Code Section 19.15.27.8.G.(1)(a).
\86\ Id. at Section 19.15.27.8.G.(1)(b).
---------------------------------------------------------------------------
The commenter evaluated all C-129 reports filed with the New Mexico
Oil Conservation Commission (OCC) between 2021 and 2025.\87\ The
commenter reported that the database contains reports filed by upstream
and midstream operators. According to the commenter, of all the causes
listed, 13 were identified that could be classified as a malfunction or
incident that could endanger the safety of operator personnel or the
public or as occurring during a repair or maintenance activities. The
commenter listed in their comment letter the various causes for these
events, including corrosion, downhole well maintenance, equipment
failure, freeze, human error, lightning, liquids unloading, overflow-
tank, pit, packer leakage test, power failure, repair and maintenance,
production test, and commissioning to purge.
---------------------------------------------------------------------------
\87\ See Attachments C and D of the commenter's letter for the
Excel workbooks that include their analysis.
---------------------------------------------------------------------------
In its analysis of the New Mexico OCC dataset, the commenter stated
that 99.7 percent of the total reported flaring incidents lasted 24
hours or less. According to the commenter, this data demonstrates that
operators can comply with a 24-hour limit on flaring during
malfunctions or incidents that endanger the safety of operator
personnel or the public and also during repair and maintenance
activities.\88\
---------------------------------------------------------------------------
\88\ See Attachments C and D of the commenter's letter for the
Excel workbooks that include their analysis.
---------------------------------------------------------------------------
Another commenter contended that the EPA's proposal to extend the
temporary flaring allowance from 24 to 48 hours and include exigent
circumstances to allow flaring up to 72 hours is a massive step in the
wrong direction. The commenter contended that this policy, while trying
to meet the demands of a changing industry, critically ignores the
health and environmental implications that the commenter attributed to
flaring. The commenter stated that instead of responding to concerns
raised by oil and gas companies, thereby allowing what the commenter
described as further damage to health and safety, there should be more
focus on stricter regulations that veer toward alternative modes of
energy production.
Response: For the reasons explained here, the EPA found comments
suggesting that the EPA should retain the 24-hour allowance for
temporary flaring of associated gas for malfunction, including for
reasons of safety, and during all repairs and maintenance finalized in
the March 2024 Final Rule to be unpersuasive.\89\
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\89\ With respect to the portion of the comments suggesting that
the EPA should ``veer toward alternative modes of energy
production,'' the Agency first notes that such comments are out of
scope for this action which concerns limited technical amendments to
the temporary flaring provisions for associated gas and to NHV.
Moreover, basing a regulation under Clean Air Act section 111 on a
shift to ``alternative modes of energy production'' does not comport
with caselaw. See West Virginia v. EPA, 597 U.S. 697 (2022).
---------------------------------------------------------------------------
In finalizing the required timeframe for this provision, the EPA
considered additional factors beyond the average flaring duration
proposed in the January 2025 Proposal due to variabilities that exist
in the industry at large.
Some commenters appear to suggest that a strict 24-hour limit on
temporary flaring is warranted based on the claim that most events in
the Temporary Flaring Survey, particularly in the Permian Basin, are
resolved within that timeframe. However, this narrow interpretation of
the data, when considered in the context of setting a national
standard, ignores critical realities demonstrated across the full
dataset and operational field conditions. First, while the Permian
Basin represents a large portion of the data, flaring behavior and
operational challenges do not appear to be uniform across the
representative basins. Other regions, particularly the Williston Basin,
face significantly harsher environmental conditions and logistical
barriers that are not captured by simply focusing on Permian Basin
averages. Commenters argue that because one region generally operates
under favorable conditions, all other regions should be held to the
same standard, an approach that is neither practical nor technically
sound.
Additionally, commenters rely on averages without giving proper
weight to variability. The same dataset across all responses shows that
17 percent of flaring events lasted longer than 24 hours, and 15
percent lasted longer than 72 hours--a meaningful minority that cannot
simply be ignored. Averages can hide important outliers that matter
operationally. For instance, the high standard deviation of 156 hours
across the full dataset demonstrates that flaring durations vary
dramatically and treating all events as if they should conform to an
average disregards the complex, often unpredictable nature of these
unique situations that may result in routing associated gas.
Emergencies, severe weather, and mechanical failures in remote,
unmanned sites frequently require more than 24 hours to troubleshoot,
repair, and safely restore operations.
The EPA also disagrees with the claim that the datasets and other
information available to the Agency are too limited to support a
nationwide 72-hour flaring allowance. While the Temporary Flaring
Survey does not include every basin, it contains 2,804 flaring events
from several major oil and natural gas producing regions, providing a
meaningful sample of real-world operations. Events exceeding both 24
and 72 hours occurred across different categories. For example, in the
``Other--specify'' category of the Temporary Flaring Survey, gas sales
line freezing led o flaring durations as high as 117 hours, power
outages resulted in delays up to 48 hours, and high hydrogen sulfide
(H<INF>2</INF>S) levels forced compressor shutdowns lasting 29 hours.
In the C-129 reports filed with the New Mexico OCC that the commenter
evaluated, while these events represent a small portion of the more
than 28,000 total upstream incidents examined, there were still 127
flaring incidents lasting more than 24 hours and 103 incidents
[[Page 18073]]
lasting more than 72 hours during repair and maintenance activities.
So, even the data from New Mexico shows that 24, or even 48, hours is
not sufficient time in some instances. These examples show that
extended flaring durations can result from malfunction or safety
related issues that are not tied to any single region.
A national default limit of 72 hours is straightforward in terms of
compliance, especially for operators who work in more than one basin.
It gives enough time to fix most issues without needing to claim an
exigent circumstance. It also avoids subjecting sources across
different regions to unequal treatment, as well as avoiding situations
where sources are subject to the conditions discussed above that may
contribute to longer flaring incidents but are captured in the existing
record or analysis. Such sources could be existing sources or new
sources, and a nationwide standard for new sources obviated the need to
continually analyze and adjust regional-based considerations. For rare
cases that go beyond 72 hours, the rule allows limited flexibility as
addressed in section IV.A.1 of this preamble. And, as discussed
previously, the EPA is also requiring flaring to cease when the
incident triggering flaring has been resolved, which serves as a
protective backstop to reduce emissions notwithstanding the 72 hour
allowance. We expect that incidents that previously have been resolved
within 24 or 48 hours would continue to be resolved as quickly as
practicable and that flaring would cease when the issue is resolved.
The EPA does not dispute the general idea that the data available
to the Agency in this rulemaking docket demonstrate that many instances
of temporary flaring of associated gas are resolved, with the site
returning to normal operations, within 24 hours. However, we view this
information within the context that these instances mostly occurred at
sites that were not subject to 2024 final rule NSPS 24-hour limit at
the time of the data collection. As such, owner and operators were
already responding quickly to address repair, maintenance, and safety
issues and returning their sites to normal operations (ceasing flaring)
due to considerations outside the NSPS and EG. We have no reason to
believe that those other considerations, whatever they may be (e.g.,
State or local laws/regulations economic incentives to restore flow to
sales lines), would vanish upon finalizing the amendments to increase
the NSPS and EG timeline to 72 hours. We also have no reason to predict
that allowing up to 72 hours, or more with exigent circumstances, in
the NSPS and EG will result in owners and operators always taking up to
72 hours to return their sites to normal operations. It is reasonable
to assume that if owners and operators were addressing these issues
quickly before the NSPS, they will continue to do so after these
amendments. Seventy-two hours is a limit, not a minimum. The EPA's
regulations in no way interfere with the efforts of owners and
operators to address problems as quickly as possible. In fact, the
final regulations clarify that temporary flaring must stop when the
issue giving rise to the need to flare has been resolved. The
requirement only allows flaring for the duration of time necessary to
return the site to normal operations. If that is accomplished in eight
hours instead of 72, then the rule does not allow, let alone require,
flaring for 72 hours.
The EPA finds that certain commenters overestimate the potential
environmental consequences of revising the 24-hour requirement to a 72-
hour requirement. If the regulations provide owners and operators with
no options aside from shutting-in operations if repairs are incomplete
after 24-hours, these circumstances may lead to depressurizing
equipment directly to the atmosphere (i.e., venting). A shut-in occurs
when an owner or operator temporarily closes the valves on an oil or
gas well to stop the flow of hydrocarbons, often for maintenance,
safety, equipment issues, or economic issues. The act of restarting the
well after a shut-in can result in significant emissions due to
pressure buildup while the well was shut-in, as owners and operators
perform blowdown operations to release pressure from the well, often
resulting in significant releases of methane and other harmful
emissions.
Venting in these situations may release far more harmful emissions
than controlled flaring would over an additional 24 to 48 hours. Thus,
a rigid 24-hour limit, when compared to what is being finalized, could
result in marginally greater pollution, not less, undermining the EPA's
emission reduction goals. Further, in accordance with 40 CFR
60.5377b(d), emissions from flares and ECD are to be controlled at 95
percent reduction efficiency (see also 40 CFR 60.5391c(b) within the
model rule for the EG). While the change from 24 hours to 72 hours for
flaring in these situations, and longer for exigent circumstances, can
theoretically allow more flaring by total duration, the natural gas
being routed to a flare during this time is still being controlled at a
95 percent reduction efficiency. And as noted above, any increase in
emissions from flaring is speculative given the backstop requirement
that flaring must cease as soon as the underlying issue is resolved.
Finally, while one commenter dismissed data from the Williston
Basin as ``outliers,'' this overlooks the fact that the data from the
Williston Basin represent real operating conditions faced by numerous
facilities.\90\ The fact that the sample size from the Williston Basin
is smaller does not mean that the issues operators face there are less
legitimate. The EPA believes that utilizing a regulatory framework that
fails to accommodate areas with severe climates and operational
challenges would penalize responsible owners and operators working in
these difficult environments. The information presented to the EPA
clearly indicates that in some instances--and more than just a few
outliers--owners and operators credibly require more than 24 hours to
temporarily flare before they can resolve the problem and return the
site to normal operations. It is not appropriate for the EPA to
establish a rigid and universal, nation-wide, requirement that the
Agency has credible reason to believe cannot be met. Allowing up to 72
hours for most situations, and providing a mechanism to go beyond 72
hours, will allow owners and operators the time they need while also
ensuring that temporary flaring does not continue indefinitely or
unchecked. To use an example from one commenter, flaring for 378 hours
due to a separator backpressure valve issue where the site is
accessible would not be in compliance with the finalized amendments. We
believe that a fair and reasonable standard should reflect the full
diversity of U.S. oil and natural gas operations. A flexible allowance
permitting up to 72 hours of flaring under these circumstances is both
more practical and environmentally responsible.
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\90\ Document ID No. EPA-HQ-OAR-2024-0358-0096.
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5. Consideration of Additional Limitations and Targeted Exceptions to
Temporary Flaring
In response to the January 2025 Proposal to extend the allowable
duration for flaring associated gas from 24 to 48 hours under certain
situations, commenters also raised two distinct but related issues. The
first is whether there should be a clear cutoff for flaring within the
48-hour period. Some commenters advocated for a more restrictive
application of the proposed 48-hour allowance by recommending that the
EPA adopt an additional cutoff
[[Page 18074]]
mechanism. They requested that the EPA require owners and operators to
stop flaring as soon as the repair, maintenance, or safety issue is
resolved, even if that happens before the end of the 48-hour period.
They argued that this was needed to avoid extra flaring that serves no
technical purpose. For example, if a repair is done after 8 hours, the
commenter asserts flaring should not continue for the full allowed
temporary flaring duration. The commenter requested that the EPA
clearly state that flaring must stop when the cause of the disruption
is resolved.
Second, a separate set of comments urged the EPA to consider
geographical targeted exemptions (i.e., to explore whether exemptions
to the flaring limit should apply only in certain geographic areas such
as specific basins). These commenters argued that the EPA should not
apply the proposed 48-hour flaring allowance across the country.
Instead, they suggested that the Agency consider basin-specific
exemptions where data shows they are needed. The commenters pointed to
past EPA rules that have allowed for regional differences. For example,
the EPA has given exemptions for Alaska North Slope facilities due to
cold weather conditions. In this case, the commenter referred to the
Temporary Flaring Survey data from the Williston Basin and said it does
not support a nationwide change to the flaring limit. They further
asserted that any extended flaring allowance based on that data should
apply only in the Williston Basin.
These comments suggest that a blanket 48-hour allowance may not be
the best fit for all situations. These comments and the EPA's responses
are provided in sections IV.A.5.a and IV.A.5.b of this preamble.
a. Additional Cutoff To Limit Temporary Flaring
Comment: One commenter requested that, if the EPA finalizes the 48-
hour allowance as proposed, the EPA explicitly include an additional
cutoff for the stated allowed duration to ensure the temporary flaring
or routing to control devices ceases as soon as the malfunction is
resolved, including for reasons of safety, repair, or maintenance.\91\
The commenter contended that it is necessary for the EPA to
specifically put restrictions on the duration to require operators to
stop temporary flaring when repairs or maintenance are completed, thus
avoiding continued flaring longer than necessary during each incident.
For example, the commenter stated that if a repair or maintenance is
completed within eight hours of the need to temporarily flare
associated gas, then the flaring of associated gas should be limited to
eight hours, not a full 24 hours as allowed in the March 2024 Final
Rule. The commenter recommended regulatory text changes to 40 CFR
60.5377b(d)(1) and (2) and 40 CFR 60.5391c(c)(1) and (2) placing a
cutoff for temporary flaring to end as soon as the malfunction, safety
concern, or maintenance repair is resolved, if it did not require the
full 24 hours allowed in the March 2024 Final Rule.
---------------------------------------------------------------------------
\91\ Document ID No. EPA-HQ-OAR-2024-0358-0096.
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Additionally, the commenter stated that their recommendations are
consistent with other requirements in NSPS OOOOb and EG OOOOc, which
place an upper limit on how long provisions for certain extenuating
circumstances may apply before the baseline requirements once again
take effect, including the allowance of temporary flaring until gas
composition meets specifications or up to 72 hours, whichever is less
(40 CFR 60.5377b(d)(4)); delayed repair of centrifugal compressors (40
CFR 60.5380b(a)(8)(i)), reciprocating compressors (40 CFR
60.5385b(a)(3)(i)), fugitive emissions components until the next
scheduled shutdown or up to two years (40 CFR 60.5397b(h)(3)(i)),
whichever is earliest; repairs of pressure relief devices at gas plants
the next time monitoring personnel are onsite or within 30 days,
whichever is sooner (40 CFR 60.5400b(d)(2)). The commenter supported
this additional cutoff to ensure that temporary flaring is limited as
much as possible.
Response: The EPA agrees with the commenter's recommendation that
the finalized time for temporary flaring allowance of associated gas
should operate as a maximum timeframe. Temporary flaring or routing of
associated gas to control devices should end as soon as the
malfunction, maintenance, or safety issue is resolved. The EPA's intent
with the provisions for temporary flaring of associated gas is to allow
necessary flexibility to manage equipment issues or emergencies, while
limiting emissions to those which are associated with actions that are
required to fix the problem. This approach will encourage owners and
operators to limit flaring to the time necessary.
The EPA agrees that there is clear precedent for this type of
backstop. The March 2024 Final Rule already includes a maximum time
limit of 24 hours for temporary flaring to prevent avoidable emissions
during operational disruptions.\92\ Adding a requirement that flaring
must cease when the issue is resolved builds on this principle.
---------------------------------------------------------------------------
\92\ (Docket ID: EPA-HQ-OAR-2021-0317) Preamble, Table 17--
Situations and Durations Where Associated Gas May Temporarily be
Routed to a Flare or Control Device.
---------------------------------------------------------------------------
The monthly and annual datasets provided by industry stakeholders
show wide variation in flaring durations. The average flaring duration
across all responses was 46 hours, but the median was four hours. This
gap suggests that while some events last longer, most can be resolved
much sooner. In particular, several months showed high percentages of
events exceeding 24 and even 72 hours--up to 34 percent and 32 percent,
respectively, in January. But in other months, most events were short,
with medians below five hours. These numbers support the idea that many
events can be resolved well before the maximum time is reached and that
a cutoff based on when the issue is fixed would reduce emissions
without affecting needed flexibility. Further, in the Temporary Flaring
Survey, the Williston Basin data shows that the causes of temporary
flaring vary, including equipment failures like compressor shutdowns,
frozen gas lines, and power outages. We believe these events do not all
require the same response time. Some events can be resolved in under 10
hours. Implementing requirements to end flaring once the cause is
addressed will limit emissions to what is necessary for safe and
reliable operations. Industry stakeholders have repeatedly stated that
owners and operators are already taking steps to reduce flaring times
and that a 72-hour allowance would promote planning and operational
changes to further reduce emissions.\93\ The EPA concludes that a
backstop limit and a requirement to stop flaring when the issue is
resolved can work together to maintain the Agency's objectives while
allowing industry to respond to operational needs in an efficient and
timely manner.
---------------------------------------------------------------------------
\93\ Document ID No. EPA-HQ-OAR-2024-0358-0044.
---------------------------------------------------------------------------
b. Alternative Exemptions (e.g., Basin-Specific)
Comment: One commenter suggested that the EPA consider adopting
basin-specific exemptions from the temporary flaring provisions rather
than extending the temporary flaring allowance beyond 24 hours for all
wells nationwide.\94\ The commenter acknowledged, however, that the
current record does not support basin-specific exemptions. In
particular,
[[Page 18075]]
the commenter recommended that the EPA consider which limited
exceptions to the 24-hour duration allowance are warranted and specify
an appropriate allowance for temporary flaring or routing to control
based on data that supports that exception. According to the commenter,
the EPA has historically provided location-specific exceptions in its
oil and gas standards that account for the unique circumstances those
owners and operators face. The commenter referred to a statement the
EPA made: ``the information provided by petitioners is persuasive in
demonstrating that a blanket 24-hour limit on temporary flaring can
pose compliance challenges for certain owners and operators.'' \95\
---------------------------------------------------------------------------
\94\ Document ID No. EPA-HQ-OAR-2024-0358-0096.
\95\ 90 FR 3740 (January 5, 2025).
---------------------------------------------------------------------------
The commenter summarized key observations from the 166 instances
that the Temporary Flaring Survey API provided for temporary flaring of
associated gas in the Williston Basin (see page nine of commenter's
letter) and concluded that the Williston Basin data provides
insufficient evidence to provide a blanket nationwide exemption. The
commenter further expressed that though their position is that the data
are insufficiently clear to warrant adjusting the March 2024 Final Rule
at this time, any change in the duration of the temporary flaring
allowance based on the Williston Basin data should be limited to that
basin. The commenter noted that the EPA took similar actions on limited
exceptions for fugitive emissions monitoring requirements and process
controllers on the Alaska North Slope, citing concerns about the
technical feasibility of conducting monitoring when temperatures are
below the operating envelope of the monitoring technologies, and the
EPA noted ``there is no assurance that the initial and semiannual
monitoring that must occur during that period of time are technically
feasible.'' \96\
---------------------------------------------------------------------------
\96\ 83 FR 10628, 10632 (March 12, 2018).
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Regarding process controllers, the commenter highlighted that the
EPA provided two standards for sites in Alaska in the March 2024 Final
Rule: zero emissions for all process controllers at sites with access
to electrical power, and the use of process controllers with low
emission rates at sites with no access to electrical power (40 CFR
60.5390b(b)). Instead of the blanket move to allow 48 hours for
temporary flaring as proposed nationwide, the commenter reiterated that
any changes to the duration allowance for temporary flaring based on
the Williston Basin data should be limited to the Williston Basin and
based on a demonstrated need in the basin.
Response: Regarding the comment requesting that the EPA consider
adopting basin-specific exemptions from the temporary flaring
provisions rather than extending the temporary flaring allowance beyond
24 hours for all wells nationwide, the EPA acknowledges that we have
historically allowed some location-specific variations in oil and gas
standards to reflect operational challenges that are unique to certain
geographic regions. However, we do not find that such an approach is
necessary or supported by the current data for this rule. In the March
2024 Final Rule, the Alaska-specific provisions cited by the commenter
were granted because of distinct technical challenges related to that
region (i.e., controllers without electric power and uniqueness of
large compressors different from those in the lower 48 States \97\).
For example, we took a different approach for process controllers in
Alaska at sites without reliable access to power.\98\ This was in part
due to Alaska's northern latitude, where long periods of darkness
during winter reduce the ability of solar panels to generate
electricity. That situation presented a clear, location-specific
operational barrier that justified a different standard for certain
sources. The examples presented by the commenter both involve
subcategorization that resulted in different standards for different
sources. The differences there were meaningful enough to justify
different treatment. However, here, the differences are not as
pronounced or meaningful, and the different treatment that commenters
advocate for is only in regard to a limited variation provision that
comprises one piece of the larger applicable standard (these amendments
are not changing the substance of the NSPS standards or the EG
presumptive standards for associated gas).
---------------------------------------------------------------------------
\97\ The ``lower 48'' consists of the 48 adjoining U.S. States
and the District of Columbia of the U.S. The term excludes the only
two noncontiguous States, which are Alaska and Hawaii, and all other
offshore insular areas, such as the U.S. territories of American
Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the U.S.
Virgin Islands.
\98\ Docket ID No. EPA-HQ-OAR-2021-0317.
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The circumstances described by the commenter and the data for the
Williston Basin and other regions do not meet the same threshold as the
examples that commenters cite and do not warrant the same outcome of
creating subcategories. The Temporary Flaring Survey shows that 17
percent of temporary flaring events across all reported basins lasted
longer than 24 hours, and 15 percent exceeded 72 hours. While these
numbers suggest some operational challenges, the data also show
significant variation across both the durations and underlying causes
of these flaring events. For instance, the monthly flaring dataset
shows that in many months, the median flaring duration was just four to
six hours, even though averages were higher due to outlier events. In
June and July, for example, the average flaring durations were 11 and
19 hours, respectively, with medians of four hours. This pattern
suggests that while extended events do occur, many are resolved within
a short timeframe, even in colder months. In the Williston Basin
dataset of the Temporary Flaring Survey, temporary flaring causes range
from compressor shutdowns and frozen gas lines to facility restarts and
power outages. These are operational issues that may occur across
multiple basins. The possibility of inclement weather as a contributing
factor to site inaccessibility is not unique to any one location. The
Temporary Flaring Survey shows that events flagged as ``[u]nknown''
accounted for a much higher average flaring duration (86 hours)
compared to events where the impact of weather was known to be present
(21 hours) or absent (36 hours). This inconsistency indicates that
factors beyond location such as the nature of the malfunction, site
accessibility, and access to equipment play a large role in extended
flaring durations.
Accordingly, we find that a single, flexible nationwide approach
with clear, uniform provisions for additional time is more appropriate,
equitable, and easier to implement than finalizing different maximum
flaring times for different geographic regions of the country. As some
commenters suggested, basin-specific timelines would likely introduce
unnecessary complexity into an already complex regulatory scheme, which
could result in enforcement and compliance inconsistencies. The
standards for associated gas are already subcategorized in the NSPS
based on when a new well commenced construction. (See Table 16 in the
March 2024 Final Rule).\99\ These amendments only address two of the
four scenarios for temporary flaring (see id. at Table 17). Further,
the presumptive standards in the EG model rule are also already
subcategorized on different terms than the NSPS (see id. at Table 4).
These temporary flaring provisions are only one piece of the regulatory
scheme for associated gas, and they do not relate to
[[Page 18076]]
the standards directly. Layering basin-specific variations on top of
this scheme for certain instances of temporary flaring, which generally
should not occur often, is too complex for little to no benefit when
considered in conjunction with the requirement that flaring must cease
when the issue giving rise to the need to temporary flare is resolved.
---------------------------------------------------------------------------
\99\ 89 FR 16887 (March 8, 2024).
---------------------------------------------------------------------------
Lastly, the record does not support the conclusion that any one
basin faces persistent technical barriers that would justify a regional
variation to the originally proposed 48-hour or finalized 72-hour
temporary flaring limit. Instead, we support an approach that allows
limited extensions under exigent circumstances, as discussed in section
IV.A.1 of this preamble, but maintains a consistent framework across
all basins. This ensures fairness, limits emissions, and encourages
continued operational innovation in the oil and gas industry.
B. Vent Gas NHV Continuous Monitoring Requirements and Alternative
Performance Test (Sampling Demonstration) Option for Flares and
Enclosed Combustion Devices
The March 2024 Final Rule requires owners and operators to perform
NHV sampling for flares and ECD through continuous monitoring of NHV or
through periodic testing with sampling demonstrations. As stated in the
January 2025 Proposal, industry petitioners stated in their
reconsideration petitions that the compliance demonstrations are
unnecessary, technically infeasible, and provide a limited timeline for
compliance. The petitioners argued that over 99 percent of historical
Btu stream data already complies with the prescribed minimum NHV
content values (depending on flare type) outlined in the March 2024
Final Rule. Industry petitioners asserted that NHV content is usually a
concern when inert gases are added to the process streams, which
typically occurs during scheduled situations and is known to the
operator of the affected source.
Based on information from these petitions, as well as further
information provided by industry, in the January 2025 Proposal the EPA
proposed changes to the continuous monitoring requirements and
alternative performance test options (sampling demonstration) of NHV
for flares and ECD. First, for the continuous monitoring requirement,
we proposed to expand the streams that are exempt from monitoring NHV
to include unassisted flares and ECD at new sources, and unassisted,
air-assisted, and steam-assisted flares and ECD at existing sources. We
also proposed to replace the general exemption from NHV monitoring for
associated gas for any control device used at ``well site affected
facilities'' with NHV monitoring that is more reflective of industry
operations. Additionally, we proposed to require NHV monitoring for
streams where inert gases were added and for operational scenarios
where NHV is known to decrease (e.g., nitrogen and acid gas removal,
glycol dehydration, etc.) in flares and ECD that are subject to the 200
or 300 Btu/scf minimum requirements. The EPA relied on data provided by
industry, which showed reduced NHV from the dilution of inlet streams
by effluent streams with known high content of inerts, such as those
from amine units or produced water tank streams. In the event of stream
dilution (for any reason), owners and operators would need to satisfy
more robust recordkeeping and reporting requirements. Second, for the
alternative performance test (sampling demonstration) requirements, we
proposed to allow breaks during weekends and holidays for the March
2024 Final Rule's consecutive 14-day sampling demonstration
requirements to account for reasonable operational pauses. We also
addressed ambiguity regarding the location of NHV grab sampling methods
by specifying in the January 2025 Proposal that samples should be taken
upstream of the control device, provided that the sample is
representative of the gas being introduced to the control device.
Finally, in the January 2025 Proposal the EPA clarified NHV testing
must be reported in volumetric units (Btu/scf) instead of specific
units (Btu/lb) in order to facilitate consistency in reporting.
The EPA received several comments on the proposed amendments
regarding the NHV continuous monitoring requirements and alternative
performance test (sampling demonstration) option for flares and ECD in
the January 2025 Proposal. Highlights of these comments and the EPA's
responses are provided, as well as discussion of changes from the
January 2025 Proposal as applicable. This preamble does not discuss the
EPA's response to any of those comments. The agency's responses are
available in the EPA's RTC document (Chapter 4) for the final
rule.\100\
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\100\ Reconsideration of 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 January 2025 Proposed Rule (90 FR
3734; January 15, 2025). See Docket No. EPA-HQ-OAR-2024-0358.
---------------------------------------------------------------------------
1. 60-Day Deadline
In the January 2025 Proposal, the EPA proposed to allow 60 days for
owners and operators to conduct the continuous NHV monitoring required
by one of the options in 40 CFR 60.5417b(d)(8)(ii)(A) through (D), if
the results of the periodic sampling (i.e., three samples every five
years) indicate that the NHV is less than 1.2 times the applicable
threshold NHV level in the rule. The EPA considers it necessary to
specify a timeframe to install and operate the required continuous
monitors to provide owners and operators with regulatory certainty for
when this must occur. We consider 60 days to be an expedited time
schedule for the installation of continuous monitoring systems, but we
also consider it a reasonable timeframe for installing the necessary
grab sampling systems to automatically collect samples at least once
every eight hours as provided in 40 CFR 60.5417b(d)(8)(ii)(D). The
proposal would require facilities to collect grab samples every eight
hours until such time that a continuous monitor can be installed, and
installation of such a system may require more than 60 days. We
requested comment on the proposed 60-day compliance provision when a
five-year sampling event indicates the vent stream is not sufficiently
above the required NHV.
Comment: One commenter supported the EPA's proposed 60-day deadline
to require continuous NHV monitoring after either a periodic sample or
a post-process change re-evaluation demonstrates the flare or ECD inlet
gas is below the applicable NHV limit.\101\ The commenter stated that
more deadlines are necessary to provide clear compliance obligations.
The commenter also suggested that where a post-NHV demonstration
periodic sample is below the applicable NHV limit, the operator must
commence continuous NHV monitoring or recomplete the NHV demonstration
within 60 days of receiving the analytical results. The commenter
suggested that the opportunity to recomplete the NHV demonstration
would account for the possibility of errors in sampling or analysis.
---------------------------------------------------------------------------
\101\ Document ID No. EPA-HQ-OAR-2024-0358-0088.
---------------------------------------------------------------------------
Response: The EPA received only supportive comments regarding the
proposed clarification of allowing 60 days for implementing the
continuous NHV monitoring required by one of the options in 40 CFR
60.5417b(d)(8)(ii)(A) through (D) if the results of the periodic
sampling (i.e., three samples every five years) indicate that the NHV
is less than
[[Page 18077]]
1.2 times the applicable threshold NHV level in the rule. Hence, we are
finalizing this particular provision as proposed. Owners and operators
could resolve any potential error in sampling or analysis by
implementing a continuous NHV monitor within the newly clarified 60-day
window.
Moreover, 40 CFR 60.5417b(d)(8)(iii)(E) and 40 CFR
60.5417c(d)(8)(iii)(E) requires that if process operations are revised
that could impact (i.e., lower) the NHV of the gas sent to the enclosed
combustion device or flare, such as the removal or addition of process
equipment, owners and operators must perform a re-evaluation of the NHV
of the gas stream. The EPA is clarifying that this re-evaluation must
be performed within 60 days of the process operations being revised, on
those enclosed combustion devices and flares subject to NHV testing.
2. Revisions to Inlet Gas Streams Exempt From Monitoring
Based on information provided by petitioners after the publication
of the March 2024 Final Rule regarding NHV characteristics of sample
streams, in the January 2025 Proposal the EPA proposed changes to the
March 2024 Final Rule that would expand the scope of the exclusion for
the NHV continuous monitoring requirements and alternative performance
test (sampling demonstration) option so that the following control
devices would not be required to make any such demonstration:
unassisted flares or ECDs at new sources; and unassisted, air-assisted,
or steam-assisted flares or ECDs at existing sources. New data
submitted in API and AXPC's joint petition for reconsideration dated
April 2024 demonstrated that, for over 22,000 NHV low-pressure (LP)
data points, 99.5 percent of those data points showed that the NHV was
at least 800 Btu/scf and more than 99.9 percent of those data points
showed that the NHV was at least 300 Btu/scf. Notably, these data were
consistent across different basins.\102\ Data supplied by GPA Midstream
in its July 2024 letter supported its prior petition submittals that
gas streams in the midstream consist of natural gas and field gas with
NHVs greater than 1,000 Btu/scf, with the exception of certain streams
in which inert gases or other known low-NHV streams were added.\103\
Because these new data further demonstrate that the NHV of the vent gas
is consistently well above the 200 or 300 Btu/scf vent gas requirements
for these control devices when inerts are not present, and because
there are no combustion zone or dilution parameters for these control
devices, the EPA proposed to determine that an expanded exclusion from
the monitoring requirements is appropriate.
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\102\ 99 percent of the data were from five basins: Permian,
Anadarko, Gulf Coast (Eagleford), Williston (Bakken), and Powder
River. See March 18, 2024, API/AXPC Slides in Docket ID No. EPA-HQ-
OAR-2024-0358.
\103\ Document ID No. EPA-HQ-OAR-2024-0358-0094.
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In the January 2025 Proposal, the EPA did not propose to exclude
pressure-, steam-, or air-assisted flares or ECD from the NHV
compliance demonstration requirements for new sources. After the
January 2025 Proposal, based upon the EPA's solicitation for comment
for the sampling requirements for pressure-assisted flares and ECDs at
new and existing sources and for air- and steam-assisted flares or ECDs
at new sources,\104\ in April 2025 API supplemented its comment letter
with new high-pressure (HP) stream data (39,000 samples) from 11 basins
with over 99.5 percent of these data greater than 800 Btu/scf, which
was comparable to that of the LP NHVs previously analyzed in 2024.
Again, these were consistent across different basins.\105\ For the
combined data sets from April 2024 and April 2025, which consisted of
over 60,000 data points from both LP and HP gas streams, over 99.5
percent of the data showed NHV contents of at least 800 Btu/scf and
over 99.9 percent of the data showed NHV contents of at least 300 Btu/
scf.\106\ In this combined data set, over 99 percent of the data
samples from LP gas streams resulted in a NHV content of greater than
900 Btu/scf and over 95 percent of the data samples from HP gas streams
resulted in a NHV content of greater than 900 Btu/scf. Of particular
note, while less than 0.5 percent of the total samples yielded NHV
contents of 800 Btu/scf or less, these instances were from known
scenarios where inerts were added, namely vent gas streams from
nitrogen removal units (NRU), acid gas removal (AGR) system amine
regenerator still columns, glycol dehydrator unit reboilers without
water removal, compressors in acid gas service, or vent streams
containing water or CO<INF>2</INF> used for EOR.
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\104\ 90 FR 3748 (January 15, 2025).
\105\ 97 percent of the data were from eight basins: Permian,
Anadarko, Gulf Coast (Eagleford), Williston (Bakken), Powder River,
East Texas, Appalachian, and Arkla (Haynsville). See April 2, 2025,
API Slides in Docket ID No. EPA-HQ-OAR-2024-0358.
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As demonstrated by the July 2024 GPA Midstream data set, the
addition of inert gases or streams from amine units or produced water
tanks can decrease the NHV content of the gas stream to the point that
the NHV thresholds for non-pressure-assisted flares or ECD may not be
achieved. In addition to sources of inert streams previously identified
in the March 2024 Final Rule (i.e., streams from compressors in acid
gas service and streams from EOR facilities), the July 2024 GPA
Midstream letter explained that other operating scenarios can result in
the addition of low-Btu streams into the vent gas stream, which lowers
the overall NHV for the vent stream.
Based upon the information and data provided after the publication
of both the March 2024 Final Rule and January 2025 Proposal, which
demonstrated that over 99.5 percent of the data (consisting of both LP
and HP sources) showed NHV contents of 800 Btu/scf or greater and over
99.9 percent of the data showed NHV contents of 300 Btu/scf or greater,
the EPA is expanding the streams that are exempt from monitoring due to
high NHV content to include all flare and ECD for both new and existing
sources.
We are finalizing that NHV sampling is only required for any new or
existing flare or ECD in cases where there are contributions from
inerts, and for other miscellaneous scenarios which decrease the NHV
content, using the continuous monitoring requirements and alternative
performance test (sampling demonstration) options currently prescribed
in the NSPS OOOOb and EG OOOOc rules and summarized in section III.B of
this preamble.\107\ The EPA expects that the operational scenarios
described in section IV.B.2.c. of this preamble can be easily validated
and documented through the physical presence (or absence) of process
equipment, process piping, engineering analysis, or process flow
diagrams in order to determine when the owner or operator should
monitor the NHV of the stream.
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\107\ See 40 CFR 60.5417b(d)(8) and 40 CFR 60.5417c(d)(8).
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For example, in the case of the acid gas removal (AGR) system amine
regenerator still column vent gas, it would be easy to trace process
piping to determine whether the vent stream was routed to a dedicated
control device or was combined with affected facility vent gas streams.
Similarly, for the glycol dehydration unit reboiler vent gas, the lack
of a process condenser would indicate that higher water content (and
lower Btu) reboiler vent gas streams were combined with affected
facility vent gas streams. The use of nitrogen as
[[Page 18078]]
a blanket gas can be readily determined through the presence of
nitrogen storage, supply systems, and process piping. Finally, we
expect that storage tanks with water content high enough to depress
overall NHVs typically would not meet the applicability thresholds of
the rule and would not be combined with other vent streams routed to a
flare or ECD. However, when gas streams from produced water tanks are
vented to controls, vent lines from these tanks can be traced to
identify sources that require monitoring or sampling.
Since we proposed to remove the general monitoring exemption for
when the only inlet gas stream to the flare or ECD is associated gas
from a well affected facility, we also directly resolved one of the
issues raised in the May 2024 EIP et al. petition. We consider the data
submitted by the industry petitioners to support the proposed exclusion
from monitoring for flares and ECD subject to a vent gas NHV
requirement of 200 or 300 Btu/scf (and not subject to NHV<INF>cz</INF>
and NHV<INF>dil</INF> requirement) when no inerts are present because
the results were consistently much higher than these levels. The May
2024 EIP et al. petition also contended that the EPA did not support
its conclusion in the March 2024 Final Rule that initial assessments of
flares and other control devices, in lieu of continuous monitoring, can
capture the variability of NHV in the oil and gas sector. The EPA has
concluded that the data submitted by the industry petitioners supports
the conclusion that the NHV demonstrations required for pressure-, air-
, and steam-assisted control devices are adequate to show that the NHV
from those demonstrations is above the required thresholds specified by
the rule and that continuous monitoring is not needed. When inerts are
added intermittently or process operations change in ways that that may
lower the NHV, the proposed standards require a re-demonstration with a
new 14-day sampling effort.\108\ The re-demonstration would consider
the variability associated with these operations and determine a
reasonable lower-range value to use in compliance assessments. As such,
we proposed that the sampling requirements, with the revisions proposed
and now being finalized, are robust and sufficient to demonstrate that
continuous monitoring is not needed when the NHV of the gas stream
being controlled is sufficiently high, when considering the range of
vent gas and assist gas flow rates, to meet the required standards.
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\108\ 800 Btu/scf for pressure-assisted flares and 270 Btu/scf
for steam- and air-assisted flares.
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While we previously excluded monitoring for associated gas from the
NHV compliance demonstration requirements, some petitioners have
identified instances where the NHV for associated gas streams could be
compromised. Specifically, the use of water or CO<INF>2</INF> flooding
for EOR could introduce significant inerts as part of the associated
gas produced and thereby lower the NHV of the associated gas. We found
the information presented by the petitioners compelling and therefore
proposed to conclude that the March 2024 Final Rule's exclusion of
associated gas from the NHV compliance demonstration requirements is
overly broad. Because the definition of associated gas in the March
2024 Final Rule specifically excludes these inert gases that may be
released with the natural gas during the initial stage of separation
after the wellhead, there are cases where associated gas can have high
levels of inerts and low NHV. Therefore, the EPA proposed to remove
this exclusion for associated gas in its entirety and also requested
comment on the proposed removal of the associated gas monitoring
exemption, as well as any additional miscellaneous operating scenarios
that can compromise the NHV for associated gas streams as well as all
flare types and ECD.
a. Exemptions From NHV Monitoring
Comment: Several commenters requested exemptions from all NHV
monitoring. One commenter stated that the EPA's proposal to reconsider
the streams that are exempt from monitoring due to high NHV content for
flares or ECD at new and existing sources would allow for additional
flexibility and compliance options for regulated entities.\109\ The
same commenter asserted that extending the exemption from NHV sampling/
monitoring requirements for affected facilities under NSPS OOOOb and EG
OOOOc to streams other than associated gas to include other equipment
with consistently high NHV vent streams would allow for many upstream
facilities to demonstrate effective control of VOCs and methane while
providing flexibility and reducing the compliance burden associated
with continuous monitoring. The commenter suggested that the EPA
consider expanding the streams exempt from monitoring for unassisted
flares or ECD at new sources, and unassisted, air-assisted, and steam-
assisted flares or ECD at existing sources to create consistency
between requirements for new sources and existing sources. The
commenter added that this would provide flexibility and lessen the
compliance burden associated with applying the monitoring standards to
affected facilities under NSPS OOOOb and EG OOOOc.
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\109\ Document ID No. EPA-HQ-OAR-2024-0358-0085.
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Another commenter urged the EPA to remove all NHV monitoring
requirements for all upstream sector flares and ECD in both the NSPS
OOOOb and EG OOOOc, regardless of whether inert gas is added, and to
remove the NHV standards which prompt such monitoring.\110\ The
commenter stated that operators in the Williston Basin already collect
and analyze data throughout the well's lifecycle for permitting,
compliance, and reporting purposes and that midstream companies sample
associated gas routinely (often monthly, including composition and NHV)
to handle custody transfer payments. The commenter stated that these
operators sample and analyze using established standards and that
therefore the March 2024 Final Rule NHV monitoring requirements are
redundant.
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\110\ Document ID No. EPA-HQ-OAR-2024-0358-0091.
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The same commenter added that the manufacturer of control devices
specifies the minimum or required range of the NHV for the inlet gas
which is necessary to operate the control device effectively. Regarding
lower-Btu gas, the commenter stated that flare and ECD technology
exists (and continues to evolve) which can ensure stable combustion at
lower heating values and that imposing rigid NHV monitoring
requirements can limit innovation. The commenter stated that upstream
sector flares and ECD have consistently been designed and tested to
ensure high combustion efficiency (destruction removal efficiency (DRE)
exceeding 99 percent) without the need for complex NHV monitoring
typically required for petroleum refinery flares. The commenter pointed
to comments in the May 2024 API and AXPC petition which highlighted
fundamental differences between upstream sector flares and petroleum
refinery flares regarding NHV requirements. The commenter explained
that upstream flares are not designed with NHV requirements because
they operate under non-steady state conditions, with a more consistent
gas composition, including NHV. In contrast, the commenter noted that
the Refinery MACT includes NHV requirements and operates under steady
state conditions with varying gas
[[Page 18079]]
composition (which can include different NHV contents). The commenter
stated that upstream flares are specifically designed to maintain high
combustion efficiency even in non-steady state conditions due to the
limited variability of the vent gas composition and relatively few gas
streams routed to the control device.
Several commenters requested that NHV continuous monitoring only
apply in situations where inert gases are introduced into the vent gas
stream.\111\ Two of the commenters \112\ referred to data \113\
previously provided to the EPA which they state demonstrates that oil
and gas facilities consistently exceed the minimum NHV limits, except
for known scenarios.
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\111\ Document ID No. EPA-HQ-OAR-2024-0358-0083, -0088, -0090, -
0092, -0093, -0094, -0095.
\112\ Document ID No. EPA-HQ-OAR-2024-0358-0092, -0095.
\113\ See, e.g., Letter from American Petroleum Institute and
American Exploration & Production Council, to Michael S. Regan, US
EPA Administrator, Provisions Creating Immediate Compliance and
Implementation Issues EPA's Final Rule ``Proposed Standards of
Performance for New, Reconstructed, and Modified Sources and
Emissions Guidelines for Existing Sources: Oil and Natural Gas
Sector Climate Review,'' 5, EPA-HQ-OAR-2024-0358-0009 (April 5,
2024).
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One commenter requested that the EPA not require NHV monitoring
unless inert gases are added or for other miscellaneous scenarios which
decrease vent gas NHV regardless of type of control device.\114\ The
commenter stated that, in previous comments submitted to the EPA, they
provided data that shows the vent gas NHV is typically well above 900
Btu/scf, and therefore the NHV monitoring requirements are unnecessary
except in specific operations which introduce inert gases into the vent
gas stream. The commenter provided that the previous data set
represented LP vent gas streams and included over 22,000 data points
from 18 operators covering approximately 4,200 sites, including well
sites, central production facilities, and compressor stations. A second
data set for HP vent gas streams, collected in the same operator survey
in coordination with AXPC, is included in the commenter's letter and
represents an additional 39,000 data points from 12 operators covering
approximately 22,100 sites, primarily from well sites and central
production facilities. The commenter concluded that NHV monitoring
should only be required when inert gases are added or for other
miscellaneous scenarios which decrease vent gas NHV regardless of type
of control device.
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\114\ Document ID No. EPA-HQ-OAR-2024-0358-0083.
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Another commenter also urged the EPA to exempt NHV monitoring for
flares and ECD that control associated gas from any oil well (not just
well affected facilities under NSPS OOOOb or well designated facilities
under EG OOOOc).\115\ The commenter explained that the composition of
associated gas does not change due to regulatory applicability, and the
current associated gas exemption arbitrarily limits the scope of the
exemption.
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\115\ Document ID No. EPA-HQ-OAR-2024-0358-0088.
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Lastly, a commenter recommended that the EPA allow the NHV
monitoring exemption to apply to pressure-assisted control
devices.\116\ The commenter referenced the January 2025 Proposal in
which the EPA states that because the NHV of methane (896 Btu/scf) is
not significantly higher than the required minimum NHV of 800 Btu/scf
for pressure-assisted flares and ECD, the Agency will continue to
require either continuous monitoring or alternative performance testing
(14-day NHV test) for these devices. The commenter urged the EPA to
reconsider this approach, which they say is not supported by the record
and is contrary to common sense. The commenter further provided that
the EPA further stated in the January 2025 Proposal that `` . . . we
find that it is much easier for the NHV in the vent gas samples from
these control devices to decrease and approach the 800 Btu/scf NHV
threshold. . .'' According to the commenter, this reason does not
support costly continuous monitoring.
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\116\ Document ID No. EPA-HQ-OAR-2024-0358-0094.
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Conversely, two commenters opposed the EPA's proposal to exempt
flares and ECD from NHV monitoring. One of the commenters agreed with
the EPA's proposal to require certain flares and other control devices
controlling emissions from associated gas to monitor or sample for NHV.
According to the commenter, the EPA must do so given that some
petitioners have identified instances where the NHV for associated gas
streams could be compromised, such as in water or CO<INF>2</INF>
flooding which can introduce a large amount of inerts as part of the
associated gas produced. However, the commenter disagreed with the
EPA's proposal to require this monitoring or sampling only for
pressure-assisted flares and other controls at new and existing sources
and air- and steam-assisted flares and other controls at new sources.
The commenter stated that the EPA must also require NHV monitoring or
sampling for unassisted flares at new and existing sources and air- and
steam-assisted flares at existing sources. The commenter stated that
the EPA has failed to establish that the NHV of gases sent to flares
and other controls, including those where no inert gases are added and
nothing else decreases the NHV content of the inlet stream gas, will
always be above the March 2024 Final Rule's NHV limits. According to
the commenter, this means that the EPA cannot rationally justify a
complete exemption from NHV monitoring and sampling.
The other commenter strongly opposed the EPA's proposal to remove
NHV monitoring requirements for all new unassisted flares and ECD (with
limited exceptions due to inerts) and for existing air-assisted and
steam-assisted flares and ECD and asserted that the EPA has changed its
position without adequate justification.\117\ The commenter urged the
EPA to maintain NHV monitoring requirements for all unassisted flares
and ECD.
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\117\ Document ID No. EPA-HQ-OAR-2024-0358-0096.
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The same commenter referenced the EPA's justification for its
proposed exemption from all NHV monitoring for unassisted flares and
ECD, which cited new data \118\ provided by API, AXPC, and GPA
Midstream that the EPA claims ``appear to demonstrate that the NHV of
the vent gas is consistently well above the 200 or 300 Btu/scf vent gas
requirements for these control devices when inerts are not present, and
because there are no combustion zone or dilution parameters for these
control devices.'' \119\ The commenter suggested that several
deficiencies in the data cut strongly against the EPA's decision to
exempt all unassisted flares and ECD from the monitoring requirements.
The commenter disagreed that the Temporary Flaring Survey contains
enough information to ensure the NHV figures represent the entire vent
gas stream going to the flare or ECD. The commenter contended that
because the data sets do not specify that all samples were taken after
all vent streams were combined, it is inappropriate for the EPA to make
a sweeping exemption based solely on the data presented.
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\118\ See API-AXPC NHV Survey Results v1.0 at <a href="https://www.regulations.gov/document/EPA-HQ-OAR-2024-0358-0044">https://www.regulations.gov/document/EPA-HQ-OAR-2024-0358-0044</a>; July 31,
2024 Email from GPA (Response for additional information) at <a href="https://www.regulations.gov/document/EPA-HQ-OAR-2024-0358-0039">https://www.regulations.gov/document/EPA-HQ-OAR-2024-0358-0039</a>.
\119\ See 90 FR 3747 (January 15, 2025).
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The same commenter also supported the proposed removal of the
exemption for associated gas waste streams, which they state is
supported by the record. The commenter agreed with the EPA's assessment
of information, provided that the NHV of associated gas does not always
exceed the minimum limits as
[[Page 18080]]
the EPA expected it would when it finalized the exemption in the March
2024 Final Rule. Further, the commenter agreed that the information
provided demonstrates that associated gas can be combined with inerts,
which in turn may reduce the NHV below the required minimum thresholds.
The commenter urged the EPA to expand the inclusion of NHV monitoring
for unassisted flares and ECD where the only vent stream is associated
gas for these reasons and for the reasons discussed in other remarks by
the commenter which address the EPA's proposed exemption of unassisted
flares and ECD from all NHV monitoring.
Response: The EPA received numerous comments regarding the vent gas
NHV continuous monitoring requirements and alternative performance test
(sampling demonstration) option for flares and ECD discussed in the
January 2025 Proposal.
In general, most commenters were in favor of the EPA's proposal to
expand the streams to include unassisted flares or ECD at new sources
and to include unassisted, air-assisted, and steam-assisted flares or
ECD at existing sources, and to only require NHV monitoring for streams
where inert gases were added or in the event of operational scenarios
where NHV is known to decrease. However, most commenters disagreed with
the EPA's proposal to continue to require the NHV monitoring that is
currently required for all pressure-, air-, and steam-assisted flares
or ECD at new sources and for pressure-assisted flares or ECD at
existing sources.
To support this argument, as discussed in section IV.B.2 of this
preamble, in April 2025 API provided new HP stream data (39,000
samples) from 11 basins with over 99.5 percent of these data greater
than 800 Btu/scf, which was comparable to that of the LP NHV previously
analyzed in 2024. For the combined data sets from April 2024 and April
2025, which consisted of over 60,000 total combined data points from
both LP and HP gas streams, over 99.5 percent of the data showed NHV
contents of at least 800 Btu/scf and over 99.9 percent of the data
showed NHV contents of at least 300 Btu/scf. In this combined data set,
over 99 percent of the data samples from LP gas streams resulted in an
NHV content of greater than 900 Btu/scf and over 95 percent of the data
samples from HP gas streams resulted in an NHV content of greater than
900 Btu/scf. The EPA reviewed the ``Sample Description/Source'' field
in both the LP and HP data sets and concluded that the sources for
which NHVs were determined are representative of gases that may be
controlled by a flare or ECD. In turn, the EPA found this additional
data form a robust, reliable, and representative data set to support a
compelling argument to include both the LP and HP data (which comprises
data from unassisted, air-assisted, and steam-assisted flares and ECD)
as its justification to expand the streams that are exempt from
monitoring (due to typically high NHV contents, on average) to include
all flare and ECD for both new and existing sources.\120\
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\120\ As summarized in footnotes 106 and 108, 99 percent of the
LP data were from five basins and 97 percent of the HP data were
from eight basins, which geographically represent the primary basins
located throughout the United States.
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While the EPA recognizes that in some instances sources may not
achieve the applicable and prescribed NHV content values in NSPS OOOOb
and EG OOOOc, industry commenters have presented sufficient information
to conclude that these instances occur where inert gases are added or
under other miscellaneous scenarios that
[…truncated; see source link]Indexed from Federal Register on April 9, 2026.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.