3734 Federal Register / Vol. 90, No. 9 / Wednesday, January 15, 2025 / Proposed Rules 

* * * * * 

PART 70—STATE OPERATING PERMIT 

PROGRAMS 

■ 3. The authority citation for part 70 

continues to read as follows: 

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

■ 4. Appendix A to part 70 is amended 

by adding paragraph (h) under ‘‘Kansas’’ 

to read as follows: 

Appendix A to Part 70—Approval 

Status of State and Local Operating 

Permits Programs 

* * * * * 

Kansas 

* * * * * 

(h) The Kansas Department of Health and 

Environment submitted revisions to Kansas 

rules K.A.R. 28–19–517, on February 20, 

2023. The State effective date is December 

23, 2022. This revision is effective [30 days 

after date of publication of the final rule in 

the Federal Register]. 

* * * * * 

[FR Doc. 2024–31626 Filed 1–14–25; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 60 

[EPA–HQ–OAR–2024–0358; FRL–12031–01– 

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: Proposed rule. 

SUMMARY: The Environmental Protection 

Agency (EPA) is proposing 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 petitions for reconsideration. 

Specifically, this action proposes 

discrete technical changes to two 

different aspects of the rules. First, this 

action proposes discrete technical 

changes to the temporary flaring 

provisions for associated gas in certain 

situations. Second, this action proposes 

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 devices. 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 March 8, 2024 

(89 FR 16820) final rule. These 

amendments neither propose changes to 

any other aspect of the final rule, nor 

propose to alter the substance of any 

emission standards within the final rule. 

Also, in this action, the EPA proposes 

to make formatting changes to the 

regulatory text to meet the required 

formatting standards of the Office of the 

Federal Register. 

DATES: Comments. Comments must be 

received on or before March 3, 2025. 

Public Hearing. If anyone contacts us 

requesting a public hearing on or before 

January 20, 2025, we will hold a virtual 

public hearing. Please refer to the 

SUPPLEMENTARY INFORMATION for 

information on requesting and 

registering for a public hearing. 

ADDRESSES: You may send comments, 

identified by Docket ID No. EPA–HQ– 

OAR–2024–0358, by any of the 

following methods: 

• Federal eRulemaking Portal: 

https://www.regulations.gov (our 

preferred method). Follow the online 

instructions for submitting comments. 

• Email: a-and-r-docket@epa.gov. 

Include Docket ID No. EPA–HQ–OAR– 

2024–0358 in the subject line of the 

message. 

• Mail: U.S. Environmental 

Protection Agency, EPA Docket Center, 

Docket ID No. EPA–HQ–OAR–2024– 

0358, Mail Code 28221T, 1200 

Pennsylvania Avenue NW, Washington, 

DC 20460. 

• Hand/Courier Delivery: EPA Docket 

Center, WJC West Building, Room 3334, 

1301 Constitution Avenue NW, 

Washington, DC 20004. The Docket 

Center’s hours of operation are 8:30 

a.m.–4:30 p.m., Monday–Friday (except 

Federal Holidays). 

Instructions: All submissions received 

must include the Docket ID No. for this 

rulemaking. Comments received may be 

posted without change to https://

www.regulations.gov, including any 

personal information provided. For 

detailed instructions on sending 

comments and additional information 

on the rulemaking process, see the 

SUPPLEMENTARY INFORMATION section of 

this document. 

FOR FURTHER INFORMATION CONTACT: 

Frank Benjamin-Eze, Sector Policies and 

Programs Division (E143–05), Office of 

Air Quality Planning and Standards, 

U.S. Environmental Protection Agency, 

109 T.W. Alexander Drive, P.O. Box 

12055 RTP, North Carolina 27711; 

telephone number: (919) 541–3753; and 

email address: benjamineze.frank@

epa.gov. Additional questions may be 

directed to the following email address: 

O&GMethaneRule@epa.gov. 

SUPPLEMENTARY INFORMATION: 

Participation in virtual public 

hearing. To request a virtual public 

hearing, contact the public hearing team 

at (888) 372–8699 or by email at 

SPPDpublichearing@epa.gov. If 

requested, the virtual public hearing 

will be held via virtual platform. The 

EPA will announce the date of the 

hearing and further details on the 

virtual public hearing at https://

www.epa.gov/controlling-air-pollutionoil-and-natural-gas-operations. The 

hearing will convene at 11:00 a.m. 

Eastern Time (ET) and will conclude at 

4:00 p.m. ET. The EPA may close a 

session 15 minutes after the last preregistered speaker has testified if there 

are not additional speakers. 

The EPA will begin pre-registering 

speakers for the hearing no later than 1 

business day after a request has been 

received. To register to speak at the 

virtual hearing, please use the online 

registration form available at https://

www.epa.gov/controlling-air-pollutionoil-and-natural-gas-operations or 

contact the public hearing team at (888) 

372–8699 or by email at 

SPPDpublichearing@epa.gov. The last 

day to pre-register to speak at the 

hearing will be January 27, 2025. Prior 

to the hearing, the EPA will post a 

general agenda that will list preregistered speakers at: https://

www.epa.gov/controlling-air-pollutionoil-and-natural-gas-operations. 

The EPA will make every effort to 

follow the schedule as closely as 

possible on the day of the hearing; 

however, please plan for the hearings to 

run either ahead of schedule or behind 

schedule. Each commenter will have 4 

minutes to provide oral testimony. The 

EPA encourages commenters to submit 

a copy of their oral testimony as written 

comments to the rulemaking docket. 

The EPA may ask clarifying questions 

during the oral presentations but will 

not respond to the presentations at that 

time. Written statements and supporting 

information submitted during the 

comment period will be considered 

with the same weight as oral testimony 

and supporting information presented at 

the public hearing. 

Please note that any updates made to 

any aspect of the hearing will be posted 

online at https://www.epa.gov/ 

controlling-air-pollution-oil-andnatural-gas-operations. While the EPA 

expects the hearing to go forward as set 

forth above, please monitor these 

websites or contact the public hearing 

team at (888) 372–8699 or by email at 

SPPDpublichearing@epa.gov to 


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determine if there are any updates. The 

EPA does not intend to publish a 

document in the Federal Register 

announcing updates. 

If you require the services of a 

translator or a special accommodation 

such as audio description, please preregister for the hearing with the public 

hearing team and describe your needs 

by January 22, 2025. The EPA may not 

be able to arrange accommodations 

without advance notice. 

Docket. The EPA has established a 

docket for this rulemaking under Docket 

ID No. EPA–HQ–OAR–2024–0358. All 

documents in the docket are listed in 

the Regulations.gov index. Although 

listed in the index, 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 as pdf versions 

that can only be accessed on the EPA 

computers in the docket office reading 

room. Certain data bases and physical 

items cannot be downloaded from the 

docket but may be requested by 

contacting the docket office at (202) 

566–1744. The docket office has up to 

10 business days to respond to these 

requests. With the exception of such 

material, publicly available docket 

materials are available electronically in 

Regulations.gov. 

Written Comments. Submit your 

comments, identified by Docket ID No. 

EPA–HQ–OAR–2024–0358, at https://

www.regulations.gov (our preferred 

method), or the other methods 

identified in the ADDRESSES section. 

Once submitted, comments cannot be 

edited or removed from the docket. The 

EPA may publish any comment received 

to its public docket. Do not submit to 

the EPA’s docket at https://

www.regulations.gov any information 

you consider to be CBI or other 

information whose disclosure is 

restricted by statute. This type of 

information should be submitted as 

discussed in the Submitting CBI section 

of this document. 

Multimedia submissions (audio, 

video, etc.) must be accompanied by a 

written comment. The written comment 

is considered the official comment and 

should include discussion of all points 

you wish to make. The EPA will 

generally not consider comments or 

comment contents located outside of the 

primary submission (i.e., on the Web, 

cloud, or other file sharing system). 

Please visit https://www.epa.gov/ 

dockets/commenting-epa-dockets for 

additional submission methods; the full 

EPA public comment policy; 

information about CBI or multimedia 

submissions; and general guidance on 

making effective comments. 

The https://www.regulations.gov 

website allows you to submit your 

comment anonymously, which means 

the EPA will not know your identity or 

contact information unless you provide 

it in the body of your comment. If you 

send an email comment directly to the 

EPA without going through https://

www.regulations.gov, your email 

address will be automatically captured 

and included as part of the comment 

that is placed in the public docket and 

made available on the internet. If you 

submit an electronic comment, the EPA 

recommends that you include your 

name and other contact information in 

the body of your comment and with any 

digital storage media you submit. If the 

EPA cannot read your comment due to 

technical difficulties and cannot contact 

you for clarification, the EPA may not 

be able to consider your comment. 

Electronic files should not include 

special characters or any form of 

encryption and be free of any defects or 

viruses. 

Submitting CBI. Do not submit 

information containing CBI to the EPA 

through https://www.regulations.gov. 

Clearly mark the part or all of the 

information that you claim to be CBI. 

For CBI information on any digital 

storage media that you mail to the EPA, 

note the docket ID, mark the outside of 

the digital storage media as CBI, and 

identify electronically within the digital 

storage media the specific information 

that is claimed as CBI. In addition to 

one complete version of the comments 

that includes information claimed as 

CBI, you must submit a copy of the 

comments that does not contain the 

information claimed as CBI directly to 

the public docket through the 

procedures outlined in the Written 

Comments section of this document. If 

you submit any digital storage media 

that does not contain CBI, mark the 

outside of the digital storage media 

clearly that it does not contain CBI and 

note the docket ID. Information not 

marked as CBI will be included in the 

public docket and the EPA’s electronic 

public docket without prior notice. 

Information marked as CBI will not be 

disclosed except in accordance with 

procedures set forth in 40 Code of 

Federal Regulations (CFR) part 2. 

Our preferred method to receive CBI 

is for it to be transmitted electronically 

using email attachments, File Transfer 

Protocol (FTP), or other online file 

sharing services (e.g., Dropbox, 

OneDrive, Google Drive). Electronic 

submissions must be transmitted 

directly to the Office of Air Quality 

Planning and Standards (OAQPS) CBI 

Office at the email address oaqps_cbi@

epa.gov, and as described above, should 

include clear CBI markings and note the 

docket ID. If assistance is needed with 

submitting large electronic files that 

exceed the file size limit for email 

attachments, and if you do not have 

your own file sharing service, please 

email oaqps_cbi@epa.gov to request a 

file transfer link. If sending CBI 

information through the postal service, 

please send it to the following address: 

OAQPS Document Control Officer 

(C404–02), OAQPS, U.S. Environmental 

Protection Agency, 109 T.W. Alexander 

Drive P.O. Box 12055 RTP, North 

Carolina 27711, Attention Docket ID No. 

EPA–HQ–OAR–2024–0358. The mailed 

CBI material should be double wrapped 

and clearly marked. Any CBI markings 

should not show through the outer 

envelope. 

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: 

AGR Acid gas removal 

AMP Alternative Monitoring Plan 

API American Petroleum Institute 

ASTM American Society for Testing and 

Materials 

BPV back pressure valve 

BSER best system of emission reduction 

Btu/lb British thermal units per pound 

Btu/scf British thermal units per standard 

cubic feet 

°C degrees Celsius 

CAA Clean Air Act 

CBI Confidential Business Information 

CFR Code of Federal Regulations 

CO2 carbon dioxide 

CRA Congressional Review Act 

CVS closed vent systems 

EG emission guidelines 

EJ environmental justice 

EOR enhanced oil recovery 

EPA Environmental Protection Agency 

FR Federal Register 

ft3 cubic feet 

GC gas chromatograph 

GHG greenhouse gas 

GHGRP Greenhouse Gas Reporting Program 

ICR information collection request 

MACT maximum achievable control 

technology 

MS mass spectrometer 

NAICS North American Industry 

Classification System 

NHV net heating value 

NHVcz combustion zone NHV 

NHVdil NHV dilution parameter 

NHVS net heating values 

NSPS new source performance standards 

NTTAA National Technology Transfer and 

Advancement Act 


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1See the EPA’s website, https://www.epa.gov/ 

tribal/tribes-approved-treatment-state-tas, for 

information on those Tribes that have treatment as 

a state for specific environmental regulatory 

programs, administrative functions, and grant 

programs. 

O2 oxygen 

OAQPS Office of Air Quality Planning and 

Standards 

OMB Office of Management and Budget 

PRA Paperwork Reduction Act 

RFA Regulatory Flexibility Act 

RIA regulatory impact analysis 

RLSO redline strike out 

scf standard cubic feet 

TAR Tribal Authority Rule 

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. Does this action apply to me? 

B. 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? 

III. Summary and Rationale of Proposed 

Amendments to NSPS OOOOb and EG 

OOOOc 

A. Temporary Flaring Provisions for 

Associated Gas in Certain Situations 

B. Vent Gas Net Heating Value (NHV) 

Continuous Monitoring Requirements 

and Alternative Performance Test 

(Sampling Demonstration) Option for 

Flares and Enclosed Combustion Devices 

IV. How do these proposed amendments 

impact the implementation of EG 

OOOOc? 

V. Summary of Cost, Environmental, and 

Economic Impacts 

VI. Statutory and Executive Order Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review and Executive 

Order 14094: Modernizing Regulatory 

Review 

B. Paperwork Reduction Act (PRA) 

C. Regulatory Flexibility Act (RFA) 

D. Unfunded Mandates Reform Act 

(UMRA) 

E. Executive Order 13132: Federalism 

F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

Risks and Safety Risks 

H. Executive Order 13211: Actions 

Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use 

I. National Technology Transfer and 

Advancement Act (NTTAA) and 1 CFR 

Part 51 

J. Executive Order 12898: Federal Actions 

To Address Environmental Justice in 

Minority Populations and Low-Income 

Populations and Executive Order 14096: 

Revitalizing Our Nation’s Commitment 

to Environmental Justice for All 

I. General Information 

A. Does this action apply to me? 

The source category that is the subject 

of this proposal is the Crude Oil and 

Natural Gas Source Category regulated 

under Clean Air Act (CAA) section 111, 

New Source Performance Standards 

(NSPS) and Emission Guidelines (EG). 

The 2022 North American Industry 

Classification System (NAICS) code for 

the source category is summarized in 

table 1. The NAICS codes serve as a 

guide for readers outlining the entities 

that this proposed 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 1—INDUSTRIAL SOURCE CATEGORIES AFFECTED BY NSPS ACTION

Category NAICS code Examples of regulated entities 

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. 

This table is not intended to be 

exhaustive but rather provides a guide 

for readers regarding entities likely to be 

affected by the NSPS action. Other types 

of entities not listed in the table could 

also be affected by these NSPS action. 

To determine whether your entity is 

affected by any of the NSPS action, you 

should carefully examine the 

applicability criteria found in the final 

NSPS rule. If you have questions 

regarding the applicability of the NSPS 

rule to a particular entity, consult the 

person listed in the FOR FURTHER

INFORMATION CONTACT section, your State 

air pollution control agency with 

delegated authority for NSPS, or your 

EPA Regional Office. 

The issuance of the CAA section 

111(d) EG in March of 2024 did not 

impose binding requirements directly 

on existing sources. The EG codified in 

40 CFR part 60, subpart OOOOc, applies 

to States in the development, submittal, 

and implementation of State plans to 

establish performance standards to 

reduce emissions of GHGs from 

designated facilities that are existing 

sources on or before December 6, 2022. 

Under the Tribal Authority Rule (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 in a manner 

similar to 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 the authority from the 

EPA to establish a TIP, the EPA has the 

authority to establish a Federal CAA 

section 111(d) plan for designated 

facilities that are located in areas of 

Indian country.1 A Federal plan would 

apply to all designated facilities located 

in the areas of Indian country covered 

by the Federal plan unless and until the 

EPA approves a TIP applicable to those 

facilities. 


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2The EPA characterizes the oil and natural gas 

industry operations as being generally composed of 

4 segments: (1) Extraction and production of crude 

oil and natural gas (‘‘oil and natural gas 

production’’), (2) natural gas processing, (3) natural 

gas transmission and storage, and (4) natural gas 

distribution. 

3 ‘‘Standards of Performance for New, 

Reconstructed, and Modified Sources and 

Emissions Guidelines for Existing Sources: Oil and 

Natural Gas Sector Climate Review.’’ Proposed rule 

(86 FR 63110; November 15, 2021). 

4The EPA defines the Crude Oil and Natural Gas 

source category to mean: (1) Crude oil production, 

which includes the well and extends to the point 

of custody transfer to the crude oil transmission 

pipeline or any other forms of transportation; and 

(2) natural gas production, processing, 

transmission, and storage, which include the well 

and extend to, but do not include, the local 

distribution company custody transfer station, 

commonly referred to as the ‘‘city-gate.’’ 

5The term ‘‘designated facility’’ means ‘‘any 

existing facility which emits a designated pollutant 

and which would be subject to a standard of 

performance for that pollutant if the existing facility 

were an affected facility.’’ See 40 CFR 60.21a(b). 

6 ‘‘Standards of Performance for New, 

Reconstructed, and Modified Sources and 

Emissions Guidelines for Existing Sources: Oil and 

Natural Gas Sector Climate Review.’’ Supplemental 

notice of proposed rulemaking (87 FR 74702; 

December 6, 2022). 

B. Where can I get a copy of this 

document and other related 

information? 

In addition to being available in the 

docket, at Docket ID No. EPA–HQ– 

OAR–2024–0358 located at https://

www.regulations.gov/, an electronic 

copy of this action is available on the 

internet at https://www.epa.gov/ 

controlling-air-pollution-oil-andnatural-gas-operations. In accordance 

with 5 U.S.C. 553(b)(4), a brief summary 

of this proposed rule may be found at 

www.regulations.gov, Docket ID No. 

EPA–HQ–OAR–2024–0358. Following 

publication in the Federal Register, the 

EPA will post the Federal Register 

version of the proposal and key 

technical documents at this same 

website. 

A memorandum showing the edits 

that would be necessary to incorporate 

the changes to 40 CFR part 60 subpart 

OOOOb and 40 CFR part 60 subpart 

OOOOc proposed in this action is 

available in the docket (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 https://www.epa.gov/ 

controlling-air-pollution-oil-andnatural-gas-operations. 

II. Statutory Background and 

Regulatory History 

A. Statutory Background of CAA 

Sections 111(b), 111(d), and General 

Implementing Regulations 

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 establish EG 

for States to establish standards of 

performance for certain pollutants 

emitted by existing sources in that 

source category. For a comprehensive 

discussion of the statutory background 

of CAA sections 111(b), 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 Proposal) to mitigate climatedestabilizing pollution and protect 

human health by reducing greenhouse 

gas (GHG) and volatile organic 

compound (VOC) emissions from the oil 

and natural gas industry,2 specifically 

the Crude Oil and Natural Gas source 

category.3 4 In the November 2021 

Proposal, the EPA proposed new and 

updated standards of performance 

under section 111(b) of the CAA for 

GHGs (in the form of methane 

limitations) and VOC emissions from 

new, modified, and reconstructed 

sources in this source category, as well 

as revisions to standards of performance 

already codified at 40 CFR part 60, 

subparts OOOO and OOOOa. The EPA 

also proposed EG under section 111(d) 

of the CAA for GHGs emissions (in the 

form of methane limitations) from 

existing sources (designated facilities).5

The EPA also proposed several related 

actions stemming from the joint 

resolution of Congress, adopted on June 

30, 2021, under the Congressional 

Review Act (CRA), disapproving the 

EPA’s final rule titled, ‘‘Oil and Natural 

Gas Sector: Emission Standards for 

New, Reconstructed, and Modified 

Sources Review,’’ September 14, 2020 

(2020 Policy Rule). Lastly, in the 

November 2021 Proposal the EPA 

proposed a protocol for optical gas 

imaging (OGI) under the part 60 general 

provisions. The only portions of the 

November 2021 Proposal that are 

relevant to this rulemaking are specific 

limited provisions of the NSPS 

(OOOOb) and EG (OOOOc) identified in 

this proposal. 

On December 6, 2022, the EPA 

published a supplemental proposed rule 

(‘‘December 2022 Supplemental 

Proposal’’) that was composed of two 

main additions.6 First, the EPA 

proposed updated, strengthened, and 

expanded NSPS OOOOb standards 

compared to those proposed in 

November 2021 under CAA section 

111(b) for GHGs (in the form of methane 

limitations) and VOC emissions from 

new, modified, and reconstructed 

facilities. Second, the EPA proposed 

updated, strengthened, and expanded 

presumptive standards compared to 

those proposed for EG OOOOc in the 

November 2021 Proposal as part of the 

CAA section 111(d) EG for GHGs 

emissions (in the form of methane 

limitations) from designated facilities. 

For purposes of EG OOOOc, the EPA 

also proposed the implementation 

requirements for State plans developed 

to limit GHGs pollution (in the form of 

methane limitations) from designated 

facilities in the Crude Oil and Natural 

Gas source category under CAA section 

111(d). 

On March 8, 2024, at 89 FR 16820 

(hereafter, referred to as the March 2024 

final rule), the EPA published the final 

rule with multiple separate actions to 

reduce air pollution emissions from the 

Crude Oil and Natural Gas source 

category. First, the EPA finalized NSPS 

OOOOb regulating GHG (in the form of 

a limitation on emissions of methane) 

and VOCs emissions for the Crude Oil 

and Natural Gas source category 

pursuant to CAA section 111(b)(1)(B). 

Second, the EPA finalized the EG in 

OOOOc to limit GHGs. Third, the EPA 

finalized several related actions 

(including final amendments to NSPS 

OOOOa) stemming from the joint 

resolution of Congress, adopted on June 

30, 2021, under the CRA, disapproving 

the 2020 Policy Rule. Fourth, the EPA 

finalized a protocol under the General 

Provisions for optical gas imaging (OGI). 

The final rule became effective 60 days 

after publication, which was May 7, 

2024. 

After the publication of the March 

2024 final rule, the EPA identified, 

through its own internal reassessment of 

the regulatory text, as well as through 

communications with stakeholders and 

the Office of the Federal Register, 

erroneous cross-references and 

typographical errors within the 

regulatory text. Through those same 

processes, the EPA also identified the 

need for some minor wording changes 

to clarify erroneous language (or, in 

some cases, erroneous omissions) in the 

regulatory text, and to ensure that the 


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7 Docket ID No. EPA–HQ–OAR–2021–0317–4057. 

8See Docket No. EPA–HQ–OAR–2024–0358 for 

petitions for reconsideration received. 

9See Docket No. EPA–HQ–OAR–2024–0358 for 

May 6, 2024, letter granting reconsideration. 

10Letter 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. May 6, 2024. Hereinafter referred to 

as the ‘‘May 2024 API and AXPC petition.’’ 

11Letter 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.’’ 

12Letter 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.’’ 

13Letter 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.’’ 

14 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. 

15To view the proposed formatting changes, see 

the full redline strike out (RLSO) of the regulatory 

text located in the public docket at EPA–HQ–OAR– 

2024–0358. 

regulatory text aligns with the 

descriptions of the relevant provisions 

in the final rule preamble and other 

parts of the regulation(s). The EPA 

published an interim final rule (89 FR 

62872; August 1, 2024) 7 which made 

minor and non-substantive corrections 

to the March 2024 final rule in order to 

correct the identified inadvertent errors. 

Further, after the publication of the 

March 2024 final rule, the EPA received 

multiple petitions 8 for reconsideration. 

On May 6, 2024,9 we notified certain 

petitioners and the public that we 

granted reconsideration on two narrow 

and discrete aspects of the March 2024 

final rule: (1) The temporary flaring 

provisions for associated gas in certain 

situations; and (2) the vent gas NHV 

continuous monitoring requirements 

and alternative performance test 

(sampling demonstration) option for 

flares and enclosed combustion devices. 

These issues were raised in petitions for 

reconsideration from: (1) The American 

Petroleum Institute (API) and the 

American Exploration and Production 

Council (AXPC); 10 (2) Second petition 

from API/AXPC; 11 (3) The Texas Oil & 

Gas Association (TXOGA); 12 (4) GPA 

Midstream Association (GPA 

Midstream); and (4) Environmental 

Integrity Project et. al.13 This action 

proposes amendments to the March 

2024 final rule as a result of our 

reconsideration of these two narrow 

issues.14

III. Summary and Rationale of 

Proposed Amendments to NSPS 

OOOOb and EG OOOOc 

The amendments proposed in this 

action only relate to two narrow aspects 

of the March 2024 final rule: (1) The 

temporary flaring provisions for 

associated gas in certain situations; and 

(2) the vent gas NHV continuous 

monitoring requirements and alternative 

performance test (sampling 

demonstration) option for flares and 

enclosed combustion devices. This 

proposal does not address, and therefore 

the EPA is not reopening, any other 

aspects of the March 2024 final rule 

aside from these two specific aspects. 

Further, the two issues addressed in this 

proposal 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. Also, in this action, the EPA 

proposes to make formatting changes to 

the regulatory text to meet the required 

formatting standards of the Office of the 

Federal Register.15

A. Temporary Flaring Provisions for 

Associated Gas in Certain Situations 

The final NSPS OOOOb requirements, 

and EG OOOOc presumptive standards 

(model rules), allow oil wells that are 

not routinely flaring associated gas (i.e., 

oil wells that route associated gas to 

sales line or equivalent alternative), to 

route associated gas to a flare or control 

device temporarily in certain situations. 

During situations where a malfunction 

or incident endangers the safety of 

operator personnel or the public, and 

during repair, maintenance including 

blow downs, a production test, or 

commissioning, owners and operators 

are allowed to route to a flare or control 

device for 24 hours or less per incident. 

Petitions for reconsideration include 

information that suggest that 24 hours 

for temporary flaring may not be 

sufficient time in these situations to 

troubleshoot and repair equipment. A 

summary of the relevant promulgated 

provisions being reconsidered is 

presented in section III.A.1, and specific 

concerns and supporting information 

provided by petitioners and other 

industry representatives are presented 

in section III.A.2 of this preamble. After 

consideration of the petitioners’ 

concerns and supporting information, 

the EPA is proposing certain discrete 

changes to these particular requirements 

finalized in the March 2024 final rule. 

The proposed changes are presented in 

section III.A.3 of this preamble and the 

EPA’s rationale for those proposed 

changes is presented in section III.A.4 of 

this preamble. 

1. Summary of Promulgated Provisions 

Being Reconsidered 

When developing the March 2024 

final rule requirements for associated 

gas, the EPA recognized that temporary 

situations may occur beyond the 

reasonable control of an owner or 

operator that could make it technically 

infeasible or unsafe to comply with the 

standard that requires the associated gas 

be recovered and either routed into a gas 

gathering flow line or collection system 

to a sales line, used as an onsite fuel 

source, used for another useful purpose 

that a purchased fuel or raw material 

would serve, or reinjected into the well 

or inject the recovered gas into another 

well. Therefore, for all associated gas 

wells subject to NSPS OOOOb and 

complying with one of these four 

options, the final rule allows owners 

and operators to route the associated gas 

to a flare or control device temporarily. 

40 CFR 60.5377b(d). The EG also 

includes similar provisions as part of 

the model rule at 40 CFR 60.5391c(c). 

The NSPS OOOOb final rule allow 

temporary flaring for the following 

situations: 

(1) During a malfunction or incident 

that endangers the safety of operator 

personnel or the public, an owner or 

operator is allowed to route to a flare or 

control device for 24 hours or less per 

incident. 

(2) During repair, maintenance 

including blow downs, a production 

test, or commissioning, an owner or 

operator is allowed to route to a flare or 

control device for 24 hours or less per 

incident. 

(3) During a temporary interruption in 

service from the gathering or pipeline 

system, an owner or operator is allowed 

to route to a flare or route to a control 

device for the duration of the temporary 

interruption not to exceed 30 days per 

incident. 

(4) During periods when the 

composition of the associated gas does 

not meet pipeline specifications for 

sources, or when the composition of the 

associated gas does not meet the quality 

requirements for use as a fuel for 

sources, or when the composition of the 

associated gas does not meet the quality 

requirements for another useful 

purpose, an owner or operator is 


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Federal Register / Vol. 90, No. 9 / Wednesday, January 15, 2025 / Proposed Rules 3739 

16April 2024 API and AXPC petition. 

17 89 FR 16820, at 16949. 

18API (Prepared for API by John Beath 

Environmental, LLC). Operator Survey: Temporary 

Flaring. Slide Presentation and Excel Workbook. 

July 2024. 

19The Williston Basin spans western North 

Dakota, northwestern South Dakota, eastern 

Montana and into a southern section of Canada. 

20Hess Briefing for the EPA: Oil and Natural Gas 

Final Methane Rule NSPS OOOOb and EG OOOOc. 

February 29, 2024, Slide Presentation. See slides 

19–23. 

allowed to route to a flare or control 

device until the associated gas meets the 

required specifications or for 72 hours 

per incident, whichever is less. 

This proposed rule only concerns the 

first two situations listed above: (1) 

Malfunction/safety, and (2) repair/ 

maintenance. The EPA is not reopening 

the other two situations listed. 

Specifically, the EPA is proposing 

changes to the following regulatory text 

only: 40 CFR 60.5377b(d)(1) and (2), and 

60.5391c(c)(1) and (2). To view the 

proposed changes, see the full redline 

strike out (RLSO) of the regulatory text 

located in the public docket at EPA– 

HQ–OAR–2024–0358. 

2. Petitioner’s Concerns and Supporting 

Information 

The EPA received a petition for 

reconsideration of the March 2024 final 

rule from API–AXPC16 that included 

support for the EPA’s general approach 

finalized at 40 CFR 60.5377b(d) that 

allows temporary flaring of associated 

gas for unique situations. However, 

petitioners highlighted that there are 

certain oil and natural gas production 

operations that are remote and spread 

out over many miles that are prone to 

severe winter weather events that could 

prevent operators from accessing these 

remote sites for longer than 24 hours. 

They provided, for example, that 

seasonal weather in North Dakota may 

cause local agencies to close roads 

whereby people and equipment would 

be prevented from arriving at a location 

within 24 hours. They requested that 

the EPA extend the temporary flaring 

provisions for malfunction and repair or 

maintenance activity to 72 hours from 

24 hours as finalized. They added that 

the March 2024 final rule’s specific 

timing restrictions for flaring were not 

in the proposals and therefore they did 

not have the opportunity to comment on 

the timelines finalized. 

The petitioners added that the March 

2024 final rule preamble includes 

language that they believe indicates that 

the EPA intended to allow up to 72 

hours for temporary flaring, ‘‘. . .during 

repair, maintenance including 

blowdowns, a packer leakage test, a 

production test, or commissioning.’’ 17

Petitioners asking the EPA to reconsider 

this issue interpreted that it was the 

EPA’s intention that 72 hours be 

allowed for temporary flaring, ‘‘. . . 

during repair, maintenance including 

blowdowns, a packer leakage test, a 

production test, or commissioning,’’ 

based on language in the final rule 

preamble. 

However, the EPA is now clarifying 

that the language cited by Petitioners 

was an inadvertent error. Elsewhere in 

the final rule preamble (e.g., Table 17— 

Situations and Durations where 

Associated Gas May Temporarily be 

Routed to a Flare or Control Device) and 

the final rule regulatory text correctly 

specify 24 hours as the allowance for 

temporary routing to a flare or control 

device during repair and maintenance. 

The final rule does allow for up to 72 

hours in a different scenario, if 

associated gas does not meet pipeline 

specifications. In the March 2024 final 

rule, the EPA did not intend, and the 

existing regulatory text does not permit, 

to allow up to 72 hours for repair and 

maintenance. 

As a follow-up to their petition, API 

conducted a survey 18 from June through 

July 2024 with its members to 

understand the distribution of 

temporary associated gas flaring 

duration due to malfunction or 

maintenance and repair and submitted 

to the EPA for consideration. The API 

survey-provided responses include 

information on duration, data (month 

and year), and cause of temporary 

flaring events due to malfunction or 

maintenance or repair based on readily 

available data collected over 6 years 

(with 70 percent of the data collected 

within the last 3 years). The API survey 

data set represents over 2,800 total data 

points from six operators across three 

basins. The majority of the information 

(92 percent of the data points) was from 

the Permian Basin, with 6 percent and 

2 percent from the Williston and San 

Juaquin Basins, respectively. Overall, 

according to API, the results indicate 

that over 17 percent of events across the 

three basins required temporary flaring 

greater than 24 hours per event and over 

15 percent of events required temporary 

flaring greater than 72 hours per event. 

Broken down by basin, 12 percent of the 

events in the Permian Basin required 

temporary flaring greater than 24 hours, 

and 11 percent required flaring 

durations greater than 72 hours. For the 

Williston Basin, 92 percent of events 

required flaring for greater than 24 

hours and 78 percent required flaring 

for greater than 72 hours. For the San 

Joaquin Basin, 7 percent of events 

required flaring greater than 24 hours 

and 0 percent required flaring greater 

than 72 hours. The average duration of 

a temporary flaring event for all basins 

was reported to be 46 hours. The 

average flaring event durations by basin 

were 26 hours for the Permian Basin, 

378 hours for the Williston Basin, and 

8 hours for the San Joaquin Basin. API 

reported that inclement weather is one 

of many factors that contributes to the 

need for longer temporary flaring 

durations, which is reflected in the 

longer durations in the Williston 

Basin.19 They concluded that the data 

set supports their position that a 24- 

hour limit is a potential issue across 

various causes of temporary flaring 

including planned events, with 

geographically dispersed sites 

presenting additional challenges to 

rapid response. 

Additional takeaways from the survey 

data, according to API, are that: (1) 

Operators are already making efforts to 

reduce the duration of temporary 

flaring, with approximately 83 percent 

of flaring events represented in the data 

set being less than 24 hours; and (2) API 

believes that a 72-hour flaring limit 

would be more realistic, force 

operational innovation, minimize 

emissions, and would reduce the 

duration of roughly 15 percent of 

events. API acknowledged that although 

the results of the survey may not be 

statistically representative of the entire 

population (the entire industry in terms 

of all wells with associated gas), they 

believe that the collected data indicates 

that 72 hours is more appropriate than 

24 hours as a national standard for 

temporary flaring due to malfunction or 

planned repair and maintenance. 

The EPA had also received a briefing 

by Hess Corporation prior to receiving 

the April 2024 API and AXPC petition 

on temporary flaring concerns.20 Their 

briefing stressed that well sites are 

unmanned facilities that are spread over 

hundreds of miles throughout North 

Dakota. They stressed that seasonal 

conditions such as road restrictions in 

spring and fall and extreme winter 

conditions can prevent personnel and 

equipment from getting to site, and that 

it may take days and up to over a week 

until access roads to a well site are 

cleared of snow. They added that, if a 

maintenance crew is required for repair, 

it can take multiple days even with 

equipment available. They suggested 

that it would be more appropriate and 

achievable for the EPA to allow 72 


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3740 Federal Register / Vol. 90, No. 9 / Wednesday, January 15, 2025 / Proposed Rules 

21Hess Briefing for the EPA: NSPS OOOOb 

Safety, Malfunction & Repair Temporary Flaring 

Allowance. June 3, 2024. Slide Presentation. 

22 89 FR 16943 to 16944 and 89 FR 16948 to 

16950. 

hours for temporary flaring due to safety 

and repair conditions. 

Hess Corporation provided two 

specific scenarios in their briefing that 

they believe would require the need for 

flaring greater than 24 hours: (1) Back 

pressure valve (BPV) failure; and (2) 

frozen sales gas piping on well site. 

Under the first scenario, they reported 

that it can take over a week to fix a BPV 

where an operator cannot fix it without 

involving others to perform corrective 

work and to obtain the necessary parts. 

Under the second scenario, once a 

freeze is identified, mitigation needs to 

be scheduled with a 3rd party and work 

can entail over a day to remove snow to 

provide access to thaw piping. 

In June of 2024, Hess Corporation 

presented an updated briefing 21 to the 

EPA on their concerns related to the 

temporary flaring provisions which 

included additional supporting 

information for the above-mentioned 

scenarios. For example, for the first 

scenario above, Hess provided BPV 

failure notification to resolution 

timeline data indicating that it takes 

anywhere from a half day to 8 days 

(with an average resolution time of 3.2 

days). Hess emphasized that weatherrelated closures/restrictions that prevent 

personnel and repair equipment from 

getting to a site, and well sites in North 

Dakota that are unmanned facilities 

spread over hundreds of miles are both 

instances that would prevent 

maintenance and repair within 24 hours 

as required by the March 2024 final 

rule. Hess represented that their 

operations in North Dakota span an area 

of roughly 7,200 square miles. Thus, the 

company stated that even under normal 

business processes—that incorporate 

efficiencies—maintenance and repair 

within 24 hours is unlikely and 

infeasible in many instances, even 

without a reason beyond an operator’s 

control. 

3. Summary of Proposed Changes 

After consideration of the petitioners’ 

concerns and supporting information, 

the EPA is proposing to revise the 

temporary flaring provisions for 

associated gas in certain situations 

finalized in the March 2024 final rule. 

Specifically, these proposed revisions 

only apply to situations during: (1) 

Malfunction/safety, and (2) repair/ 

maintenance. The EPA is proposing to 

extend the allowable time for temporary 

flaring from 24 to 48 hours for 

malfunction, including for reasons of 

safety, and during all repairs and 

maintenance. 

Further, the EPA recognizes 

Petitioners’ claim that there may be 

some instances in which an owner or 

operator encounters a malfunction, 

safety, repair, or maintenance event that 

requires routing to a flare or control 

device beyond 48 hours. To address 

such instances, the EPA is soliciting 

comment on allowing owners or 

operators of associated gas affected 

facilities to route to a flare or control 

device for up to 72 hours 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/road closures, the EPA 

is also soliciting comment on whether 

there are other specific ‘‘exigent 

circumstances’’ where the EPA should 

consider allowing an owner or operator 

to include as a basis of a ‘‘exigent 

circumstance’’ claim requiring the need 

to route to a flare or control device 

beyond the proposed 48-hour allowance 

for repairs and malfunctions. The EPA 

also solicits comment on the records 

and reports that should be required 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.’’ Specifically, 

the EPA solicits comment on requiring 

an owner or operator who must make 

use of the extended timeframe to 

maintain records that include: (1) A 

written description of the ‘‘exigent 

circumstance’’; (2) the rationale for the 

need to route to a flare or control device 

beyond 48 hours; (3) a description of the 

measures taken to minimize temporary 

flaring/routing to a control device; and 

(4) the duration of temporary flaring/ 

routing to a control device due to the 

identified ‘‘exigent circumstance.’’ 

Lastly, the EPA solicits comment on 

requiring an owner or operator to 

include a summary of their annual 

‘‘exigent circumstance’’ recorded events 

in their annual report. 

The basis for the EPA’s proposed 

changes and solicitations is discussed in 

III.A.4 of this preamble. 

4. Basis for Proposed Changes 

The March 2024 final rule allows 

temporarily routing associated gas to a 

flare or control device for 24 hours 

during situations where a malfunction 

or incident endangers the safety of 

operator personnel or the public, and 

during repair, maintenance including 

blow downs, a production test, or 

commissioning. These provisions were 

based on requirements of existing State 

rules, information from the World Bank 

Global Flaring and Methane Reduction 

Partnership, and specific 

recommendations provided by 

comments received on the proposal and 

supplemental proposal.22

As discussed in section III.A.2 of this 

preamble, industry petitioners indicated 

that the 24-hour limitation for 

temporary routing to a flare or control 

device in the final rule during situations 

where a malfunction or incident 

endangers the safety of operator 

personnel or the public, and during 

repair, maintenance including blow 

downs, a production test, or 

commissioning, is not sufficient. They 

claim that a 72-hour timeframe for all 

these situations is more appropriate for 

temporary routing to a flare or control 

device due to the unique characteristics 

of some well sites, weather conditions, 

or a combination of both. 

The EPA considered this information, 

and examined the scenarios provided by 

the petitioners where they claimed there 

was a need for temporary routing to a 

flare or control device beyond 24 hours. 

First, 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. While we still 

expect that owners and operators can 

feasibly limit temporary flaring to less 

than 24 hours in a large majority of 

situations (and this is supported by the 

API survey data cited above), we 

acknowledge that in certain instances, 

fundamental aspects of well site 

operational schedules can make this 

requirement challenging, particularly 

for remote unmanned sites. The EPA 

understands that owners’ and operators’ 

operational schedules outline the 

staffing and work shifts of oil and gas 

operations, ensuring that personnel are 

available to monitor and respond to 

issues within a designated timeframe 

while maintaining safe and efficient 

operations. We recognize that 

challenges arise when problems occur 

outside of an operator’s working hours, 

such as during night shifts, shift 

changes or when fewer staffs are present 

leading to delays in identifying and 

addressing repairs and malfunctions. 

Hess has shared information with the 

EPA highlighting how the 24 hour 

operational schedule may not be 

sufficient for quick response in such 

cases, particularly with the remote 


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Federal Register / Vol. 90, No. 9 / Wednesday, January 15, 2025 / Proposed Rules 3741 

23An example of the timeline challenges with 

well site operational schedules is presented in slide 

5 of Hess Briefing for the EPA: NSPS OOOOb 

Safety, Malfunction & Repair Temporary Flaring 

Allowance. June 3, 2024. Slide Presentation. 

24https://wwwapps.emnrd.nm.gov/OCD/OCD

Permitting/Reporting/NaturalGasWaste/Upstream

NaturalGasWasteSummaryReportExpanded.aspx. 

nature of these sites.23 We also 

recognize that the gathering of available 

parts and prioritization of corrective 

work to correct a situation, such as the 

BPV failure example cited by Hess, 

could require the need for routing to a 

flare or control device for a period 

greater than 24 hours. Further, we also 

recognize that circumstances outside of 

the control of the owner/operator, such 

as weather events, can also impact the 

ability to address the situation within 24 

hours. 

However, the EPA believes at this 

time that proposing to change the 

requirement to allow temporary routing 

to a flare or control device for up to 48 

hours is likely to address most of the 

issues raised by the petitioners. We 

maintain that equipment needs for 

failures should be planned for in 

advance to minimize routing to a flare 

or control device (i.e., owners and 

operators should plan to have 

equipment on hand for failures on site), 

and that additional time beyond 48 

hours should not be necessary to 

address issues at remote sites since 

these sites are typically accessible 

within a 24 hour period (except during 

certain conditions e.g., seasonal 

weather, road closures that may prevent 

operators from accessing the site). 

Therefore, we are proposing to double 

the time frame for which temporary 

routing to a flare or control device is 

allowed during situations where a 

malfunction or incident endangers the 

safety of operator personnel or the 

public, and during repair, maintenance 

including blow downs, a production 

test, or commissioning, from 24 hours 

per event to 48 hours per event. This 

timeframe is supported by API’s survey, 

which found the average duration of 

temporary flaring was 46 hours per 

event. 

While the EPA is proposing to change 

the allowed duration for temporarily 

routing associated gas to a flare or 

control device from 24 to 48 hours, we 

recognize that there is some information 

that could support retaining the 24-hour 

time frame. As noted above, the API 

survey indicated that 83 percent of the 

circumstances encountered that 

required temporary flaring were 

resolved in 24 hours or less. Further, 

Colorado 2 Colo. Code. Regs. sec. 

4041:903 allow gas to be flared (or 

vented during an upset condition), but 

for a period not to exceed 24 cumulative 

hours per event. In addition, 

information from New Mexico 24

indicates that only 11 percent of the 

total volume of gas flared (from all 

sources, not only associated gas) results 

from flaring activities with durations 

greater than 8 hours. We request 

information and data on whether the 

proposed temporary flaring duration of 

48 hours has the potential to increase 

the amount of primary or secondary 

emissions. The duration of flaring will 

vary by basin and by the reason for 

flaring. We request that any data on 

changes in emissions due to flaring 

specifically identify the basin, reasons 

for flaring, and duration of the 

temporary flaring. We request that 

commenters consider this information 

in submitting comments related to the 

proposed change to 48 hours. We also 

request additional information to 

support the proposal, or to support 

retaining the 24-hour period in the final 

rule. 

While the EPA expects that the vast 

majority of temporary flaring situations 

can be addressed within the 48-hour 

timeframe proposed in these 

amendments, we recognize that 

incidents might not be resolved within 

48 hours due to circumstances beyond 

an owner or operator’s control. 

Examples of such ‘‘exigent 

circumstances’’ mentioned by the 

petitioners include road closures and 

seasonal weather that could prevent 

operators from accessing the site to 

conduct a necessary repair. As 

discussed above, EPA is not proposing 

to allow temporary flaring beyond 48 

hours during such circumstances; 

however, we are soliciting comment on 

the need to allow routing to a flare or 

control device for up to 72 hours where 

a legitimate and supported ‘‘exigent 

circumstance’’ claim is made. We solicit 

comment on what would constitute an 

exigent circumstance and defining these 

incidences. Relatedly, we are soliciting 

comment on the potential ‘‘exigent 

circumstances’’ recordkeeping criteria 

explained above, and on when an 

‘‘exigent circumstance’’ claim should be 

sent to the Agency (in the annual report 

or otherwise). This longer time frame of 

up to 72 hours for special situations is 

consistent with the duration 

recommended by reconsideration 

petitioners. We acknowledge that such 

circumstances represent real-life 

scenarios that are beyond an owner or 

operator’s control but seek more 

information on this as an option. See 

section III.A.3 of this preamble for more 

explanation on our solicitation for 

information. 

B. Vent Gas Net Heating Value (NHV) 

Continuous Monitoring Requirements 

and Alternative Performance Test 

(Sampling Demonstration) Option for 

Flares and Enclosed Combustion 

Devices 

A summary of the relevant 

promulgated provisions being 

reconsidered related to the vent gas 

NHV continuous monitoring 

requirements and alternative 

performance test (sampling 

demonstration) option for flares and 

enclosed combustion devices is 

presented in section III.B.1, and specific 

concerns and supporting information 

provided by petitioners and other 

industry representatives are presented 

in section III.B.2 of this preamble. After 

consideration of the petitioners’ 

concerns and supporting information, 

the EPA is proposing certain discrete 

changes to these particular requirements 

finalized in the March 2024 final rule. 

The proposed changes are presented in 

section III.B.3 of this preamble and the 

EPA’s rationale for those proposed 

changes is presented in III.B.4 of this 

preamble. 

1. Summary of Promulgated Provisions 

Being Reconsidered 

The EPA finalized compliance 

requirements for continuous monitoring 

and initial and periodic performance 

testing for flares and enclosed 

combustion devices in the March 2024 

final rule. Of relevance to this proposal 

are the final 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 enclosed combustors must 

maintain the NHV of the gas sent to the 

device above a minimum NHV value if 

the combustion device is pressureassisted or uses no assist gas. If an 

owner or operator uses a steam- or airassisted enclosed combustion device or 

flare, the owner or operator must 

maintain the combustion zone NHV 

(NHVcz) above a minimum level. If the 

owner or operator uses an air-assisted 

enclosed combustion device or flare, the 

owner or operator must maintain the 

NHV dilution parameter (NHVdil) above 

a minimum level. The NHVcz and 

NHVdil parameter terms account for the 

reduction in heating value caused by the 

introduction of air or steam. These 


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3742 Federal Register / Vol. 90, No. 9 / Wednesday, January 15, 2025 / Proposed Rules 

25Under 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-andgas-alternative-test-methods#:∼:text=The

%20application%20portal%20can

%20be,Air%20Emission%20Measurement

%20Center%20web page. Since the rule’s 

publication date of March 8, 2024, 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 https://www.epa.gov/emc/broadlyapplicable-approved-alternative-test-methods. 

26Per 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.’’ 

27April 2024 API and AXPC petition. 

28May 2024 API and AXPC petition. 

29May 2024 TXOGA petition. 

30May 2024 GPA Midstream petition. 

31May 2024 EIP, et al. petition. 

32For 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, 

carbon dioxide (CO2), water, or other compounds 

that have a net heating value of zero. 

terms ensure that the assist gas does not 

overwhelm the heating value provided 

by the vent gas to the point where 

proper combustion is no longer 

occurring. Owners or operators also 

have the option to apply to use an 

alternative test method that either 

demonstrates continuous compliance 

with the combustion efficiency limit or 

directly demonstrates continuous 

compliance with the NHVcz operating 

limit and, if applicable, the NHVdil

operating limit. 

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. For each enclosed combustor 

and flare 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. As an alternative to continuous 

monitoring of NHV, the owner or 

operator may conduct a performance 

test to demonstrate the NHV of the vent 

stream consistently exceeds the 

applicable NHV operating limit in one 

of two ways: (1) Continuous sampling 

for 14 consecutive days plus ongoing (3 

samples every 5 years) sampling, or (2) 

manual sampling (twice daily for 14 

consecutive days) plus ongoing (3) 

samples every 5 years) sampling. The 

minimum collection time for each 

individual manually collected sample 

must be at least one hour. 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. 

Owners or operators also have the 

option to use an alternative test 

method 25 26 that demonstrates 

continuous compliance with the 

combustion efficiency limit; 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 enclosed 

combustion device or flare. Owners or 

operators of steam-assisted and airassisted enclosed combustors and flares 

also must monitor the vent gas and 

assist gas flow rates and calculate NHVcz

and NHVdil in accordance with the 

provisions in 40 CFR 63.670 (i.e., the 

refinery maximum achievable control 

technology rule, or Refinery MACT). 

Alternatively, owners or operators of 

air-assisted flares may provide a onetime demonstration based on maximum 

air assist rates, minimum waste gas flow 

rates (based on back pressure regulator 

setting), and minimum NHV from the 

most recent sampling rather than 

continuously monitor vent gas and 

assist gas flow rates. 

Finally, as discussed in section II.B of 

this preamble, the EPA issued a letter on 

May 6, 2024, whereby the EPA clarified 

performance testing deadlines with 

respect to the alternative NHV sampling 

demonstration that owners or operators 

must meet in order to demonstrate 

compliance with the applicable NSPS 

subpart OOOOb emission standard. The 

EPA stated that as applied to the March 

2024 final rule, affected sources that 

were new, modified, or reconstructed 

after the supplemental proposal 

(December 6, 2022), but before the rule’s 

effective date of May 7, 2024, have 180 

calendar days after the effective date of 

the rule to conduct performance (i.e., 

compliance) testing. For NSPS subpart 

OOOOb sources that are new, modified 

or reconstructed after the final rule’s 

effective date of May 7, 2024, the 

applicable monitoring requirements 

(including the 14-day NHV performance 

test) must be completed within 180 

calendar days after initial startup of the 

source. 

2. Petitioners’ Concerns and Supporting 

Information 

API and AXPC27 28, TXOGA 29, GPA 

Midstream 30, and EIP 31 raised issues in 

their petitions relating to the March 

2024 final rule requirements for the 

NHV compliance demonstration, which 

consists of either monitoring the NHV 

content of the vent gas on a continuous 

basis, or utilizing the alternative 

performance test option. The April and 

May 2024 API and AXPC petitions, May 

2024 TXOGA petition, and May 2024 

GPA Midstream Association petitions 

raised issues regarding the need for the 

NHV compliance demonstration, 

technical infeasibility of the 

demonstration, and compliance timing 

(including supply chain issues). The 

May 2024 EIP, et. al. petition 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, and that no sampling or 

monitoring of NHV is needed when only 

associated gas from wells is sent to 

control devices. 

a. Need for NHV Compliance 

Demonstration 

The April and May 2024 API and 

APXC and May 2024 GPA Midstream 

petitions state that vent gases in this 

industry are not expected to fall below 

the minimum NHV unless diluted by 

inert gases,32 and therefore the NHV 

requirements in the March 2024 final 

rule are unnecessary. The May 2024 

GPA Midstream petition raised concerns 

with operations in the midstream and 

stated that waste gas streams routed to 

combustion devices have very high 

British thermal unit (Btu) values, when 

compared to the minimum NHV values 

finalized in the March 2024 final rule, 

because these midstream gas streams 

consist of natural gas and field gas with 

NHVs typically in excess of 1,000 Btu/ 

standard cubic feet (scf). Further, this 

petitioner stated that inert gases, such as 

nitrogen, are rarely used at midstream 

sources and any water in the gas is 

eliminated well before the control 

device. This petitioner also cited to 

prior responses to public comments 


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33See RTC, Response II–17–46 and II–17–47. 

34See 89 FR 16966. 

35 GPA Midstream—EPA 06/24/24 Meeting 

Follow-Up. Re: Response to EPA Request for 

Additional Information regarding OOOOb GPA 

Midstream Net Heating Value Case Scenarios and 

Data. (Attachment Summarizing NHV Data 

Included as an Attachment). Hereinafter referred to 

as the ‘‘July 2024 GPA Midstream Letter.’’ 

36 July 2024 GPA Midstream Letter. 

37API/AXPC–EPA 03/18/24 Meeting Follow-Up. 

Operator Survey: Net Heating Value. API–AXPC 

Meeting Slide Presentation to the EPA. (Attachment 

Summarizing NHV Data Included as an Attachment. 

Excel Sheet Provided of Analysis of NHV Data 

Provided by Operators: Supporting Data (Prepared 

by John Beath Environmental, LLC for API/AXPC).) 

38See: GPA 2145—‘‘Table of Physical Properties 

for Hydrocarbons and Other Compounds of Interest 

to the Natural Gas Industry.’’ 

from the EPA which acknowledged the 

NHV of the vent gas to a flare in this 

sector is likely to be well above the 

minimum required NHV 33 and 

questioned what it perceived as a 

change in the EPA’s position 34 in the 

March 2024 final rule. In a letter 35 to 

the EPA dated July 31, 2024, GPA 

Midstream provided additional 

information, not previously provided 

during the course of the prior 

rulemaking, regarding operating 

scenarios in midstream operations 

where vent gases may have a lower NHV 

than typical gathering, boosting, and 

processing operations. In this same 

letter, GPA Midstream also provided 

new NHV data from gathering, boosting, 

and processing vent gas streams routed 

to controls, along with four new 

operating scenarios for the EPA’s 

consideration, where the NHV content 

in vent gas streams may be lower than 

normal: 

1. Combining acid gas removal (AGR) 

system amine regenerator still column 

vent gas with affected facility vent gas 

streams—GPA Midstream explained 

that AGR amine regenerator still column 

vent gases typically are routed to an 

individual control device due to the low 

flow rate, low pressure, and corrosive 

nature of the vent stream, and that the 

low NHV of the stream typically 

requires supplemental gas for proper 

control device operation. However, GPA 

Midstream explained it is possible to 

combine the still column vent gas with 

other vent gas streams, which would 

lower the NHV of the combined stream, 

primarily due to the high CO2 content 

of the still column vent gas. 

2. Combining glycol dehydration unit 

reboiler vent gas with affected facility 

vent gas streams without water 

removal—GPA Midstream explained 

that typically glycol dehydration unit 

reboiler vent gas is routed through a 

condenser to remove liquids (including 

VOC and water vapor) and then routed 

to a process or control device. However, 

it is possible to combine the glycol 

dehydration unit reboiler gas, without 

routing through a condenser, with other 

vent gases routed to common control. 

The high water content of the reboiler 

vent gas stream could lower the NHV of 

the combined vent gas streams. 

3. Use of inert gases and entrainment 

in affected facility vent gas stream— 

GPA Midstream explained that 

midstream operations usually do not 

employ the use of inert gases such as 

nitrogen because if a blanket gas is 

needed, its midstream operations use 

natural gas as it is readily available and 

compatible with control devices due to 

the high NHV. In instances where an 

inert gas such as nitrogen is used as a 

blanket gas, this could cause lower NHV 

of the vent gas stream. 

4. High water content in vent gas 

streams from storage vessels—Finally, 

GPA Midstream explained that 

midstream operations employ the use of 

storage vessels for storing hydrocarbons 

and produced water, which typically 

have NHVs well above the thresholds 

required by the March 2024 final rule. 

However, it is possible that some 

production areas could have higher 

water content in the vent stream coming 

from the storage vessels, which would 

lower the NHV. GPA Midstream notes 

that in these cases, the high water 

content would increase the probability 

that the storage vessel emissions 

thresholds for applicability would not 

be exceeded. In any event, GPA 

Midstream explained that in such 

scenarios, the NHVs are still above the 

lower NHV thresholds of the rule. 

GPA Midstream summarized that 

midstream operators would be aware of 

the operating scenarios provided and 

should be allowed to use process 

knowledge to assess whether the NHV 

could not meet the requirements of the 

March 2024 final rule, and thus would 

require the use of supplemental gas. 

GPA Midstream also provided a new 

data set 36 of sampled data and modeled 

data from midstream operations, stating 

that the data indicate that the vent gas 

streams are well above the NHV 

requirements of the rule and hence 

should not require continuous NHV 

monitoring. GPA Midstream further 

explained technical difficulties in 

collecting the data, which are described 

in section III.B.b of this preamble. 

The April 2024 API and AXPC 

petition referred to an NHV data set 37

that they provided to the EPA after 

publication of the March 2024 final rule 

which included over 22,000 data points 

from 18 operators across approximately 

4,200 sites. The petitioners stated that 

this data set showed that more than 99.5 

percent of the time NHV values were at 

least 800 Btu/scf and more than 99.9 

percent of the time the NHV value was 

at least 300 Btu/scf. API and AXPC 

further stated that the results appeared 

consistent across five basins, 

representing 99 percent of the data. 

While some sources with multiple data 

points showed variability, the NHV was 

still well above 800 Btu/scf for those 

sources. API and AXPC stated that all 

NHV data ≤ 900 Btu/scf in the survey 

were from known scenarios where large 

amounts of inert gas(es) are expected. 

The petitioners stated that operators 

know which scenarios or sites have the 

potential for large amounts of inert gases 

to reduce the NHV of vent streams 

below the required minimum; these 

known scenarios include: (1) Sites in 

fields using water or CO2 flood 

Enhanced Oil Recovery (EOR), and (2) 

produced water tanks not co-located 

with oil tanks in certain dry gas plays. 

The April 2024 API and AXPC 

petition also included a letter from SPL, 

which stated it is the largest laboratory 

in the United States (U.S.) specializing 

in the analysis of hydrocarbon products, 

processing more than 225,000 natural 

gas samples each year. SPL stated that 

based on its direct experience analyzing 

thousands of vent gas samples from 

every major oil and gas producing 

region of the U.S. annually, it would be 

exceptionally uncommon for the NHV 

content of vent gas to fall below the 

threshold levels established by the 

March 2024 final rule. SPL explained 

that vent gases are exceptionally heavy 

gases (relative to air) that are typically 

depleted with respect to lighter 

hydrocarbon molecules such as methane 

and ethane, and enriched in molecules 

like propane, butane and pentane. As a 

result, SPL explained that these heavy 

gases have a lower vapor pressure 

(relative to a methane-enriched sales 

gas, for example) and therefore do not 

‘‘flash’’ from the liquid hydrocarbon 

stream until the final stage of 

separation. The vendor provided NHV 

data for methane (909.4 Btu/ft3), 

propane, n-butane and n-pentane (2,315 

Btu/ft3, 3,000 Btu/ft3 and 3,707 Btu/ft3

respectively).38 Therefore, SPL 

explained that, unless there is a source 

of inert gas diluting the vent gas stream 

(sources of inert gas could be added by 

design, or, due to leaking equipment), 

there should be no compositional reason 

the NHV of that gas would be under the 

threshold set by the EPA. 

b. Technical Infeasibility 

The April and May 2024 API and 

AXPC petitions, May 2024 TXOGA 


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39API and AXPC specifically point to Colorado 

and New Mexico as examples. 

petition, and May 2024 GPA Midstream 

petitions raised new issues regarding 

the feasibility of conducting the 

sampling for the alternative NHV 

performance test (sampling 

demonstration), given the intermittent 

flow to control devices. The petitioners 

explained that in some cases, flow to the 

control device may occur for as little as 

a few minutes, making continuous 

monitoring or collection of single (or 28) 

one-hour samples impossible. The May 

2024 TXOGA petition also explained 

that sampling equipment is not 

designed to operate in low temperatures 

or with all types of gases. 

The April 2024 API and AXPC 

petition pointed out that while the 

March 2024 final rule reduced the 

number of required samples from 240 

(as proposed in the December 6, 2022 

supplemental rule) to 28, it did not 

address the feasibility of collecting the 

samples. API and AXPC also contended 

that extending the sampling duration 

from 10 to 14 days added time and costs 

to an already technically infeasible 

option. As noted above, these 

petitioners submitted information from 

SPL, a laboratory that stated that the 

minimum one-hour sampling 

requirement in the alternative 

performance test (sampling 

demonstration) option goes against 

traditional norms for the collection of 

natural gas grab samples and requires all 

sampling entities to deploy alternative 

strategies which are not currently 

available. SPL explained that typical 

methods for the collection of natural gas 

samples call for spot sampling 

techniques that procure gas on very 

short (seconds to minutes) timescales, 

but the one-hour requirement requires 

composite sampling techniques 

typically used in custody-transfer 

applications (and elsewhere) to be 

adapted to a more rugged and 

transportable setup. SPL suggested that 

the EPA allow sample collection 

methods such as those referenced in 

GPA 2166–22 instead. SPL also pointed 

out what it considered to be several 

issues with the use of Summa canisters 

for vent gas collection. SPL explained 

that Summa cannisters were designed 

primarily for atmospheric gas sampling 

and that in order to collect 1-hour 

samples by Summa cannister, restrictive 

flow metering devices will be required, 

which rely on a restrictive orifice to 

meter the gas into the Summa cannister. 

SPL explained that the potentially wet 

and dirty nature of flare gas will rapidly 

foul these devices, resulting in errors in 

collection and potential contamination 

bias. Instead, SPL recommended that, 

for operators and laboratories to meet 

sample demand in a reasonable manner, 

single cavity stainless steel constant 

volume cylinders should be allowed for 

sample collection so long as they are 

maintained according to the 

requirements set forth in 43 CFR 3175 

(Onshore Oil and Gas Operations; 

Federal and Indian Oil and Gas Leases; 

Measurement of Gas). 

The May 2024 GPA Midstream 

petition explained that vent gas flow 

from midstream sources to control 

devices tended to be sporadic and at 

low pressure. They stated that 

intermittent flow was particularly an 

issue for storage vessels that either have 

low flows generally or have pressure 

control valves that only release short 

bursts of gas to control devices. GPA 

Midstream stated it is not possible to 

achieve the necessary flow rate for 

establishing a temperature limit, 

continuous monitoring, or one-hour 

sampling without adding gas pressure. It 

further explained that storage vessels 

will frequently be unable to add sweep 

gas because the necessary headspace is 

limited; in situations where facilities 

add gas, those situations will not be 

representative of normal operating 

conditions. In the July 2024 GPA 

Midstream letter, GPA Midstream 

provided further examples of sample 

collection issues. In addition to the 

availability of sampling ports, discussed 

below, GPA Midstream noted that 

closed vent systems (CVS) operate 

under a slight vacuum or close to 

atmospheric pressure and temperature, 

which can draw oxygen (O2) in with the 

vent stream sample. Also, because vent 

gas samples are obtained at atmospheric 

pressures, explained GPA Midstream, 

running the vent gas samples through 

the GC upon capture causes issues due 

to liquids (e.g., water) condensing 

during analysis, which often requires 

repairs to the GC. 

The April 2024 API and AXPC 

petition contended that NHV 

monitoring is not required in existing 

State regulations governing upstream 

flares and combustion emissions control 

devices and that upstream operators are 

not currently conducting NHV 

monitoring for operational or other nonregulatory reasons.39 Thus, the 

petitioners argued that the NHV 

monitoring at upstream flares and 

combustion emissions control devices 

has not been demonstrated to be feasible 

or cost-effective. 

The April 2024 API and AXPC 

petition also expressed concerns that 

the Refinery MACT-based NHVcz and 

NHVdil requirements for devices which 

use steam- and air-assist and perimeterassist air, respectively, are overly 

burdensome because well sites, central 

production facilities, and compressor 

stations are fundamentally different 

than petroleum refineries. The 

petitioners explained that the oil and 

natural gas production sector does not 

operate at steady state conditions and 

equipment design must be tailored to 

the conditions and fluid compositions 

supplied by the reservoir. They added 

that hydrocarbon fluids (including oil, 

condensate, and produced water) and 

natural gas are located thousands of feet 

below the surface and must flow to the 

surface for separation. API and AXPC 

explained that separation occurs in 

either a two- or three-phase separator 

with intermittent pulses of produced 

water sent from the bottom of the 

separator to its storage vessel, 

hydrocarbon liquids from the middle to 

its storage vessel, and natural gas off the 

top of the separator to the gathering 

system. These petitioners further 

explained that as production declines, 

management of liquids can mean that 

flow to the storage vessel can vary from 

essentially zero to high flow rates and 

quickly back to zero rapidly and often. 

According to the petitioners, the same is 

true for how vapors from the storage 

vessel will be expected to flow to a 

control device since emissions occur 

from flashing and working losses as 

liquid periodically flows into the 

storage vessel from the separator. The 

petitioners explained that this highly 

variable, non-steady state flow requires 

equipment to be sized much larger than 

ideal steady state conditions would 

dictate and makes flow measurement 

infeasible. The petitioners also provided 

that the cost for Refinery MACT controls 

and monitoring equipment at refineries 

are $1 million or more, with major 

ongoing costs. The petitioners explained 

that these costs will be much greater at 

upstream facilities without the 

necessary utilities and instrumentation 

resources available for a large complex 

facility such as a refinery and it is 

unclear whether instrumentation that is 

available that would work reliably 

under these varying operating 

conditions. 

The April and May API and AXPC 

and May 2024 GPA Midstream petitions 

also raised issues with the alternative 

test method approval process, stating 

that alternative test methods are costly 

to implement (and unlikely to be used 

by small operators) and take time for 

agency approval (and which is related to 

issues regarding compliance timing 

discussed in section IV.B.2.c of this 

preamble). The May 2024 GPA 


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40See GPA Midstream Comments on the 

Supplemental Proposed Rule (February 13, 2023) at 

42–43. See Docket ID No. EPA–HQ–OAR–2021– 

0317. 

41See GPA Midstream Comments on 

Supplemental Proposed Rule at 37–38 (need for 

additional compliance time for storage vessels); 42 

(discussing supply chain shortages contributing to 

long lead times). See Docket ID No. EPA–HQ–OAR– 

2021–0317. 

Midstream petition requested that the 

EPA revise the March 2024 final rule to 

allow alternative test methods for air 

and steam-assisted combustion devices, 

such as Video Imaging SpectroRadiometry (VISR), as the March 2024 

final rule preamble and regulatory text 

conflict with respect to what is 

allowable. Specifically, the petitioner 

cited to 89 FR 16968, which indicates 

that ‘‘an owner or operator could 

request an alternative test method to use 

a technology such as VISR that 

continuously monitors combustion 

efficiency or a technology such as 

Simplified VISR that continuously 

monitors NHVcz and NHVdil,’’ but noted 

that the associated monitoring 

requirements at 40 CFR 

60.5417b(d)(8)(iii)(H) appear to not 

allow alternative test methods to 

continuously monitor NHVcz and 

NHVdil. 

The May 2024 GPA Midstream 

petition also stated that the EPA should 

allow for compliance demonstration 

alternatives. This petitioner explained 

that design evaluations using process 

simulation software will be more than 

sufficient for midstream sources to 

document that waste streams 

consistently exceed the EPA’s minimum 

NHV values. The petitioner repeated 

prior comments to the EPA 40, that 

owners and operators can perform and 

document source-specific design 

evaluations to demonstrate that waste 

gas streams will consistently exceed the 

required minimum NHV thresholds in a 

manner similar to the evaluations used 

for condensers and carbon absorption 

units under 40 CFR 60.5413b(c). If the 

EPA does not allow for compliance 

demonstration alternatives, the 

petitioner requested that the EPA allow 

for alternative sampling locations. In the 

July 2024 GPA Midstream letter, GPA 

Midstream explained that prior to NSPS 

OOOOb, operators were not required to 

collect NHV data because process 

knowledge would support the vent 

stream as having a high NHV. Because 

of this, CVS were not designed to 

include sampling ports. In addition to 

the compliance timing reasons 

discussed in section IV.B.2.c of this 

preamble relating to ‘‘hot taps,’’ the 

petitioner requested that the EPA allow 

sampling from existing access points, 

such as thief hatches, which would 

avoid the compliance timing issues, 

unnecessary costs, and creation of a new 

opening that would be another potential 

source of fugitive emissions. The 

petitioner also requested that owners or 

operators be able to draw samples from 

storage vessel headspace, as there are 

always vapors present in the vessel 

headspace and it will be representative 

of the vent gas routed to the control 

devices. 

The May 2024 API and AXPC petition 

also requested that the EPA require a reevaluation of the of the vent gas stream 

NHV only when there are process or 

equipment changes that could result in 

a lowering of the NHV and requested 

that the EPA provide guidance regarding 

the analytical methods required for 

NHV sampling. The petitioners noted 

that the March 2024 final rule requires 

the use of American Society for Testing 

and Materials (ASTM) Method D1945– 

14 for NHV analysis but stated that this 

method is not widely available for well 

sites, centralized production facilities, 

compressor stations, and gas plants 

since it evaluates components not 

typically found in vent gas from these 

operations (e.g., helium). The 

petitioners requested that the EPA 

revise the March 2024 final rule, or at 

a minimum provide guidance, to allow 

the use of GPA 2261 and other 

appropriate alternative methods to 

measure NHV. In support of this, the 

petitioner provided information from 

SPL, which stated that ASTM D1945–14 

is not widely available and will require 

additional time for method 

development, as well as purchase or 

modification of equipment. 

c. Compliance Timing 

In addition to the compliance timing 

issues discussed above relating to 

alternative test method approval and 

test method capability development, the 

May 2024 GPA Midstream petition 

raised the issue that the March 2024 

final rule does not provide adequate 

time to conduct the testing after such an 

approval is granted. The petitioner 

explained that while 40 CFR 

60.5412b(d)(1) through (5) provides 

requirements for how the alternative test 

is performed, it provides no period of 

time by which it should be performed, 

unlike 40 CFR 60.5413b(b)(5)(i) which 

specifies that performance testing is 

required within 180 days after initial 

startup. The petitioner further notes that 

unlike continuous monitoring, which 

can be installed prior to startup of a new 

source, the alternative testing protocol 

requires the combustion device to 

already be operating in order to 

determine the destruction efficiency and 

inspect of visible emissions. The 

petitioner is concerned that the March 

2024 final rule can be read so that any 

period of operation before or during the 

alternative testing (dating back to 

December 2022 for modified sources) 

may be a deviation. The petitioner 

requests that the EPA allow 30 days 

after startup to perform alternative 

testing. 

The May 2024 TXOGA and April 

2024 API and AXPC petitions expressed 

concerns about the availability of 

sampling vendors that can perform the 

sampling. The May 2024 TXOGA 

petitioner also pointed out that finding 

viable sampling periods cannot be 

predicted due to the intermittent flow to 

the devices. The April 2024 API and 

AXPC petition estimated that a single 

sampling crew can typically visit no 

more than two or three sites in a day 

due to the geographically dispersed 

nature of upstream operations. This 

same petitioner provided statements 

from SPL stating that the number of 

samples required would be greater than 

the capacity of labs to collect and 

process in the 60-day window and that 

there are not enough gas 

chromatographs, sample cylinders, and 

human resources to make compliance 

within 60 days a possibility. 

The May 2024 GPA Midstream 

petition raised concerns with the 

feasibility of meeting compliance 

timelines for installation of sampling 

ports. The petitioner stated that the EPA 

has underestimated the number of 

sources that would be considered 

‘‘modified’’ under the Final Rule, 

resulting in the need to install monitors 

and sampling ports on thousands of 

sources in an impracticably short 

time.41 The petitioner stated that it will 

take owners and operators several 

months to procure continuous 

monitoring equipment and installation 

will take additional time. The petitioner 

provided purchase quotations from 

vendors which indicated that 

calorimeters would take eight to 12 

weeks for delivery and continuous 

monitoring devices would take up to 26 

weeks; installation would require an 

additional 2 to 3 weeks. Additional 

concerns expressed by the May 2024 

GPA Midstream petition were that 

installation of monitoring equipment or 

sampling ports on existing control 

devices requires specialized ‘‘hot tap’’ 

work, which they stated cannot be 

accomplished across the industry prior 

to the deadline for compliance 

demonstrations, due to a limited 

number of qualified contractors and the 


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need to properly time unit shutdowns 

for the hot tap work. 

d. Other 

The May 2024 EIP, et. al. petition 

contended that the EPA did not support 

the March 2024 final rule conclusion 

that initial assessments of flares and 

other control devices, in lieu of 

continuous monitoring, can capture the 

variability of NHVs in the oil and gas 

sector and asserted that no sampling or 

monitoring at all is needed when only 

associated gas from wells is sent to 

control devices. 

3. Summary of Proposed Changes 

The EPA is proposing to revise 

numerous aspects of the NHV 

monitoring and testing provisions in the 

March 2024 final rule. The EPA is 

proposing to expand the streams that are 

exempt from monitoring due to high 

NHV content to include unassisted 

flares or enclosed combustion devices at 

new sources and to include unassisted, 

air-assisted, and steam-assisted flares or 

enclosed combustion devices at existing 

sources. We are proposing that the NHV 

monitoring that is currently required 

should continue to be required for all 

pressure-assisted, air-assisted, and 

steam assisted flares or enclosed 

combustion devices at new sources and 

for pressure-assisted flares or enclosed 

combustion devices at existing sources. 

We are proposing to remove the general 

exemption from NHV monitoring for 

associated gas from well site affected 

facilities for any control device. For 

flares or enclosed combustion devices 

that are subject only to a minimum NHV 

content in the vent gas of 200 Btu/scf or 

300 Btu/scf, we are proposing to require 

NHV monitoring only in cases where 

inert gases are added, or for other 

miscellaneous scenarios which 

decreases the NHV content of the inlet 

stream gas to the enclosed combustion 

device or flare. These known 

operational scenarios include 

combining 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 EOR sites in fields 

using water or CO2 flooding. The EPA 

is proposing recordkeeping and 

reporting to indicate whether the flare 

or enclosed combustion device receives 

inert gases 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. 

In addition, when an owner or 

operator opts to meet the NHV 

compliance demonstration by 

conducting the alternative performance 

test via the NHV grab sampling option, 

the EPA is proposing revisions to clarify 

that sampling may be conducted on ‘‘the 

inlet gas which is routed to the enclosed 

combustion device or flare’’ [emphasis 

denotes proposed revision]. The EPA 

intends that this revised phrasing will 

clarify that sampling upstream of the 

inlet to the control device is allowed, 

provided that the sample is 

representative of the gas inlet to the 

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 proposing to 

clarify that the NHV of the vent stream 

shall be determined in Btu/scf, where 

standard conditions are 20 degrees 

Celsius (°C), not Btu 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. Other 

changes in this proposal include 

specifying that the 14-day period for the 

performance test (sampling 

demonstration) option shall be 

consecutive operating days and that for 

the purposes of determining the hourly 

average for continuous samples, the 

average shall be a block hourly average. 

The EPA is not proposing to amend the 

sampling frequency (i.e., 2 samples per 

day for 14 days with an ongoing 

demonstration of 3 samples every 5 

years) for the performance test 

(sampling demonstration) option for 

neither NSPS OOOOb nor EG OOOOc. 

However, the EPA is proposing to allow 

for breaks for weekends and holidays 

which may occur during the 14-day 

sampling period, such that the 14 days 

do not have to be consecutive. The EPA 

is also proposing to retain the one-hour 

minimum sampling time for the twice 

daily samples, except in cases where 

low or intermittent flow makes one-hour 

sampling infeasible. In such a case, the 

EPA is proposing to allow less than onehour sampling times and proposing that 

the sampling time used and the reason 

for the reduced sampling time must be 

documented and reported. The EPA is 

proposing to more clearly allow the use 

of the sampling methodology alternative 

to continuous monitoring in 40 CFR 

60.5417b(d)(8)(iii) for all types of air 

and steam assisted flares or enclosed 

combustion devices. The EPA is 

proposing these same changes in both 

NSPS OOOOb and EG OOOOc. 

In addition, for NSPS OOOOb, the 

EPA is proposing to retain the NHVcz

and NHVdil monitoring requirements, 

but more clearly including the 

provisions at 40 CFR 60.5417b(d)(8)(vi) 

to allow the use of approved alternative 

test methods as provided in 40 CFR 

60.5412b(d)(1)(i) and (ii) for continuous 

monitoring of NHVcz and, if applicable, 

NHVdil. We are also proposing to more 

fully delineate in 40 CFR 

60.5417b(d)(8)(iv) when flare flow or 

assist rates are not required to be 

monitored. On the other hand, for EG 

OOOOc, the EPA is proposing to remove 

the requirement to comply with and 

conduct monitoring for NHVcz and 

NHVdil for air- and steam-assisted 

enclosed combustion devices and flares 

used for existing sources. This series of 

proposed revisions in EG OOOOc 

include changes in the initial 

compliance requirements for air- or 

steam-assisted enclosed combustion 

devices or flares 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 proposing under EG OOOOc that airor steam-assisted enclosed combustion 

devices or flares must meet a minimum 

NHV in the vent gas of 300 Btu/scf. 

4. Basis for Proposed Changes 

a. Proposed Revisions to Inlet Gas 

Streams Exempt From Monitoring 

As discussed in section III.B of this 

preamble, based on new information 

provided by petitioners regarding NHV 

characteristics of sample streams, the 

EPA is proposing changes to the 

requirements in the March 2024 final 

rule that would, if finalized, 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 

enclosed combustion devices at a new 

source and for unassisted, air-assisted, 

or steam-assisted flares or enclosed 

combustion devices at existing sources. 

New data submitted in the April 2024 

API and AXPC petition demonstrated 

that, for over 22,000 NHV 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 NHV was 

at least 300 Btu/scf. Notably, these data 

were consistent across different 


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42 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. 

basins.42 Data supplied in the July 2024 

GPA Midstream letter supported their 

prior petition submittals that gas 

streams in the midstream consist of 

natural gas and field gas with NHV 

values greater than 1,000 Btu/scf, with 

the exception of certain streams in 

which inert gases or other known lowNHV streams were added. Because these 

new data 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, the EPA is proposing to 

determine that an expanded exclusion 

from the monitoring requirements is 

appropriate. 

While we previously excluded 

monitoring for associated gas from the 

NHV compliance demonstration 

requirements, some petitioners have 

now identified instances where the 

NHV for associated gas streams could be 

compromised. Specifically, the use of 

water or CO2 flooding EOR could 

introduce significant inerts as part of the 

associated gas produced and thereby 

lower NHV of the associated gas. We 

find the information presented by the 

petitioners compelling and therefore 

propose 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 does specifically exclude 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, we are proposing to remove 

this exclusion for associated gas in its 

entirety. The proposed removal of this 

exclusion would impact pressureassisted flares and enclosed combustion 

devices at both new and existing 

sources and air- and steam-assisted 

flares and enclosed combustion devices 

at new sources. 

The EPA is not proposing to exclude 

pressure-assisted flares or enclosed 

combustion devices from the NHV 

compliance demonstration 

requirements. For pressure-assisted 

flares or enclosed combustion devices, 

the required minimum NHV of 800 Btu/ 

scf is not significantly higher than the 

NHV of methane, which is 896 Btu/scf 

(using standard conditions of 68 °F (20 

°C); this value is lower than the value 

provided by SPL because they used 

60 °F as standard conditions). Therefore, 

sources that contain primarily methane 

would not require much dilution from 

inert components (e.g., nitrogen, CO2, or 

air) to be below the 800 Btu/scf NHV 

threshold for pressure-assisted flares or 

enclosed combustion devices. While the 

data provided by petitioners indicated 

that the majority of samples had NHVs 

above 800 Btu/scf, 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 and that, therefore, 

continuous NHV monitoring or an 

alternative performance test (sampling 

demonstration) is still warranted for 

pressure-assisted flares or enclosed 

combustion devices. Accordingly, we 

are proposing to retain the requirement 

that, as currently required in the March 

2024 final rule, pressure-assisted flares 

must either continuously monitor NHV 

or conduct the 14-day performance test 

sampling demonstration in order to 

ensure that the gases sent to those 

control devices have NHVs well above 

the regulatory threshold. 

For reasons described in section 

III.B.4.d of this preamble, the EPA is 

proposing to retain the NHVcz and 

NHVdil requirements for air- and steam 

assisted flares for sources subject to 

NSPS subpart OOOOb. Because these 

parameters are not only dependent on 

the NHV of the vent gas but also on the 

flow rate of the vent gas and the assist 

gas, we propose that the NHV 

demonstration is necessary (when 

continuous monitoring is not used) to 

determine a minimum NHV to use in 

the assessments under 40 CFR 

60.5417b(d)(8)(iv) and in the calculation 

of the NHVcz and NHVdil parameters in 

40 CFR 60.5417b(d)(8)(vi). 

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 minimum NHV 

thresholds for non-pressure-assisted 

flares or enclosed combustion devices 

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 value streams into the vent gas 

stream, which lowers the overall NHV 

for the vent stream. Therefore, we are 

proposing to require NHV monitoring 

for unassisted flares and enclosed 

combustion devices at new sources and 

for unassisted, air-assisted, and steamassisted flares and enclosed combustion 

devices at existing sources in cases 

where there are contributions from 

inerts. In the example cases provided in 

section III.B. of this preamble, the EPA 

expects that these operational scenarios 

can be easily validated 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. For example, in 

the case of the AGR system amine 

regenerator still column vent gas, it 

would be easy to trace process piping to 

determine if 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 was 

combined with affected facility vent gas 

streams. The use of nitrogen as a blanket 

gas can be readily determined through 

the presence of nitrogen storage, supply 

systems, and process piping. Finally, 

regarding vent streams from storage 

tanks with higher water content, the 

EPA expects that tanks with water 

content high enough to depress overall 

NHV values typically would not meet 

the applicability thresholds of the rule 

and would not be combined with other 

vent streams routed to an enclosed 

combustion device or flare. However, 

when gas streams from produced water 

tanks are vented to control, vent lines 

from these tanks can be traced to 

identify sources that require monitoring 

or sampling. 

Regarding the concerns raised in the 

May 2024 EIP, et. al. petition, since we 

are proposing to remove the general 

monitoring exemption for when the 

only inlet gas stream to the enclosed 

combustion device or flare is associated 

gas from a well affected facility, we 

directly resolve one of the issues raised 

in that petition. We consider the data 

submitted by the industry petitioners to 

support the proposed exemption from 

monitoring for flares and enclosed 

combustion devices subject to a vent gas 

NHV requirement of 200 or 300 Btu/scf 

(and not subject to NHVcz and NHVdil

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 


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43Per 40 CFR 60.5417b(d), requests for approval 

to monitor different monitoring parameters can be 

made under the Alternative Monitoring Plan (AMP) 

provisions in 40 CFR 60.13(i). 

variability of NHV in the oil and gas 

sector. We consider the data submitted 

by the industry petitioners also supports 

that the NHV demonstrations required 

for pressure-, air-, and steam-assisted 

control devices would be adequate data 

to show that the NHV from those 

demonstrations is well above the limits 

required by the rule and that continuous 

monitoring is not needed. When inerts 

are added intermittently or process 

operations change that may lower the 

NHV, the proposed standards require redemonstration with a new 14-day 

sampling effort. The new demonstration 

would consider the variability 

associated with these operations and 

determine a reasonable lower-range 

value to use in the compliance 

assessments. As such, we propose to 

find that the sampling requirements, 

with the revisions proposed, are robust 

and sufficient for the demonstration and 

that continuous monitoring is not 

needed when the demonstration shows 

the NHV value 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. 

The EPA is also requesting comment 

on the proposed removal of the 

associated gas monitoring exemption 

and the proposed requirement for 

continuous measurement or sampling 

requirements for pressure-assisted flares 

and enclosed combustion devices at 

new and existing sources and for airand steam-assisted flares or enclosed 

combustion devices at new sources. The 

EPA is requesting comment on whether 

there are other known process or upset 

condition scenarios which may 

introduce inert gases or other low-Btu 

streams into affected facility vent gas 

streams, resulting in NHV values which 

could be below the thresholds in the 

March 2024 final rule for flares and 

enclosed combustion devices subject to 

the vent gas NHV requirements of 200 

or 300 Btu/scf and necessitating a 

determination of the NHV of the 

combined stream(s). The EPA also is 

requesting comment on how the EPA 

can determine (e.g., the presence or 

absence of certain process equipment or 

piping configurations) that these 

scenarios are present at an affected 

facility and, therefore, require NHV 

continuous monitoring or the use of the 

sampling option to demonstrate that the 

mixed gas stream has sufficient NHV 

content to afford proper combustion 

efficiencies. 

b. Sampling Location and Duration for 

the Alternative Performance Test 

The EPA is reconsidering the 

requirements in the March 2024 final 

rule regarding the sampling duration for 

the alternative performance test 

(sampling demonstration) option for the 

NHV compliance demonstration, and is 

proposing to allow for shorter sampling 

times when it is technically infeasible to 

collect a grab sample for a minimum of 

one hour. While the March 2024 final 

rule included provisions for sampling 

periods of longer than 14 days (where 

needed) to collect a total of 28 samples, 

and the general provisions in 40 CFR 

60.8(b)(5) also allow for ‘‘shorter 

sampling times and smaller sample 

volumes when necessitated by process 

variables or other factors,’’ the EPA 

finds compelling the petitioners’ 

arguments and newly presented 

supporting information regarding the 

potential instances of intermittent flow 

of gas streams, which makes sampling 

for one hour technically infeasible in 

those cases (e.g., intermittent flow from 

sources with low pressure). As such, the 

EPA finds it appropriate to propose 

additional flexibility in the final rule to 

fully address these intermittent flow 

situations. Therefore, the EPA is 

proposing that sampling must be 

conducted for a minimum of one hour, 

when technically feasible. When it is 

not technically feasible to collect the 

sample for a minimum of one hour, the 

owner or operator should collect the 

sample for as long as possible, up to one 

hour. For samples taken during low or 

intermittent flow events, the collection 

time and the reason for not obtaining a 

full one-hour sample must be 

documented and reported with the NHV 

sampling results. We request comment 

on the actual duration of flow that is 

achievable in practice for those cases 

where sampling for one hour is 

technically infeasible on low pressure 

and intermittent gas streams, and why a 

one hour sample would be technically 

infeasible for those cases. 

Regarding the location for sampling, 

the EPA notes that, according to the 

March 2024 final rule, the sample must 

be taken of the inlet gas to the control 

device, but the gas need not be taken 

directly at the inlet of the control 

device. We consider a sample within the 

control device header system in a 

location after all vent streams sources 

have been added to the control device 

header as an inlet gas sample. While the 

EPA recognizes petitioners’ concerns 

with installing sampling ports or ‘‘taps’’ 

on these source types, the March 2024 

final rule does not specify a physical 

location where the sampling must 

occur. The EPA therefore does not 

believe it is necessary to specify that 

sampling may occur at another 

‘‘representative’’ location or specify 

such ‘‘representative’’ locations. The 

EPA also notes that the General 

Provisions in 40 CFR part 60 include 

procedures for alternatives to 

monitoring, including alternative 

locations for monitoring, ‘‘when the 

owner or operator can demonstrate that 

installation at alternate locations will 

enable accurate and representative 

measurements’’ 43—these provisions 

already address site-specific issues with 

conducting the alternative performance 

test (sampling demonstration) option. 

Accordingly, the EPA is proposing not 

to change the current provisions in the 

March 2024 final rule regarding 

sampling location for the NHV grab 

sample option. 

c. Methodologies for Compositional 

Analysis of the Gas Stream 

The EPA is reconsidering the 

requirements in the March 2024 final 

rule which limited the test method 

available for determining the 

compositional analysis of the gas stream 

to ASTM–D1945–14 (R2019). The EPA 

recognizes that other rules in which 

vent gases are analyzed, such as 40 CFR 

part 63 subpart CC (Refinery MACT) 

and the Greenhouse Gas Reporting 

Program (GHGRP) rule allow the use of 

other test methods. The EPA is 

soliciting comment to expand the use of 

similar consensus-based standards (e.g., 

GPA 2166 and GPA 2261) to consider if 

these additional available methods 

would alleviate petitioners’ concerns 

that ASTM–D1945 is not widely 

available and that testing laboratories do 

not have the capacity currently to 

enable its use. 

Regarding the units in which NHV is 

determined as prescribed in the March 

2024 final rule, the EPA does not 

disallow the use of measurement 

methods that determine concentrations 

in terms of weight fractions, but the 

weight fractions must be converted to 

volume fractions because the 

calculations referenced therein from 

part 63 use Btu/scf (not Btu/lb). 

Therefore, the EPA is not proposing to 

change the units in the March 2024 final 

rule, but rather proposing to clarify that 

NHV for individual components must 

be determined in units of Btu/scf 

consistent with the existing 

specification using published values of 

the component NHV per mole at 25 °C 

and 1 atmosphere and using 20 °C as the 

standard temperature for determining 

the volume corresponding to one mole 

of vent gas. We noted that SPL reported 


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44See 89 FR 16895 and 16967. 

the NHV of common constituents in 

vent gas streams at the incorrect 

temperature. Therefore, we are 

proposing to clarify that the standard 

temperature for 40 CFR part 60 (at 40 

CFR 60.18(f)(3)) is 20 °C and that the 

NHV values must be determined at this 

standard temperature. These 

clarifications are proposed to ensure the 

NHV determinations are conducted 

consistently and accurately. The EPA is 

requesting comment on the proposed 

clarifications of the NHV units of 

measure and calculation procedures. 

We are also proposing to clarify that 

Tedlar bags may be used to satisfy the 

grab sampling requirements, provided 

that the Tedlar bag qualifies as an 

‘‘evacuated container’’ as prescribed by 

section 8.2.1.1 of EPA Method 18. We 

request comment on the need to clarify 

that Tedlar bags can be used and the 

limitation proposed on when Tedlar 

bags can be used. 

d. NHVcz and NHVdil for Air- and SteamAssisted Flares and Enclosed 

Combustion Devices at Existing and 

New Sources 

The EPA is proposing to retain the 

NHVcz and NHVdil requirements for airand steam assisted flares for sources 

subject to NSPS subpart OOOOb 

because, as noted in the November 2021 

Proposal (86 FR 63246; November 15, 

2021), the EPA had received some data 

indicating air-assisted and steamassisted flares have been found 

operating outside of the conditions 

necessary to achieve at least 98 percent 

control efficiency on a continuous basis. 

We disagree with petitioners that these 

NHV-related parameters are not 

appropriate for assisted flares in the oil 

and gas industry because we had 

evidence of poor-performing assisted 

flares in the oil and gas industry. The 

EPA therefore proposes to conclude (as 

in the March 2024 final rule) that 

sufficient evidence exists demonstrating 

poor destruction efficiencies due to 

over-assisting a flare or enclosed 

combustion device, such that NHV 

compliance demonstrations are 

necessary to show that these particular 

control devices are meeting the requisite 

efficiency. The EPA requests comment 

on the proposed retention of the NHVcz

and NHVdil provisions for new sources. 

The EPA is also requesting comment on 

whether the NHVdil parameter is 

appropriate for enclosed combustion 

devices with perimeter assist air and the 

appropriate effective diameter to use in 

the calculation of NHVdil, if it is 

retained, particularly for devices with 

multiple burner tips within the enclosed 

combustion device. 

Regarding petitioner GPA’s statement 

that 40 CFR 60.5417b(d)(8)(iii)(H) 

appears to not allow alternative test 

methods to continuously monitor NHVcz

and NHVdil, we note that the provisions 

at 40 CFR 60.5417b(d)(8)(iii) are specific 

to the 14-day alternative performance 

test (sampling demonstration) option 

and do not apply to continuous 

monitoring. We did not include 

provisions for a 14-day demonstration 

using continuous monitoring of NHVcz

and NHVdil because assist rates could be 

changed and alter the control device’s 

performance. Continuous monitoring 

using alternative test methods is 

expressly provided for in 40 CFR 

60.5412b(d) and 60.5415b(f)(1)(xi). 

Additionally, we propose to clarify in 

40 CFR 60.5417b(d)(8)(vi) that 

continuous monitoring of NHVcz and, if 

applicable, NHVdil using an approved 

alternative method as provided under 

40 CFR 60.5412b(d)(1)(i) and (ii) is 

allowed and that, when using this 

alternative test method, you are not 

required to monitor NHV of the vent gas 

as specified in paragraph (d)(8)(ii) of 

this section or monitor flow rates as 

specified in paragraph (d)(8)(vi) of this 

section provided you can demonstrate 

that the maximum flow rate to the flare 

cannot cause the flare tip velocity to 

exceed 18.3 meter/second (60 feet/ 

second). The EPA requests comment on 

the proposed clarifications when using 

the alternative test method to 

demonstrate continuous compliance 

and requests comment on whether and 

how such monitoring could be used as 

part of the 14-day sampling 

demonstration. 

With respect to the monitoring 

requirements for NHVcz and NHVdil for 

air- and steam-assisted flares at new 

sources, the EPA acknowledges the 

petitioners’ concerns but is not 

proposing significant changes to this 

requirement for new sources subject to 

NSPS subpart OOOOb. However, in 

reviewing these requirements we note 

that the requirements in 40 CFR 

60.1547b(d)(8)(vi) reference NHV 

determinations using the lowest NHV 

result of the sampling demonstration in 

40 CFR 60.1547b(d)(8)(iii), but 40 CFR 

60.1547b(d)(8)(iii) did not have 

provisions for steam-assisted nor for 

certain air-assisted flares or enclosed 

combustion devices. Therefore, we are 

proposing to clarify that 40 CFR 

60.1547b(d)(8)(iii) can be used for any 

steam- or air-assisted flare or enclosed 

combustion device, and that the 

effective vent gas NHV to allow the use 

of the demonstration is 300 Btu/scf 

when using continuous 14-day sampling 

or 360 Btu/scf when using the 14-day 

grab sampling approach. This revision 

in 40 CFR 60.1547b(d)(8)(iii) is 

necessary considering the calculation 

provision in 40 CFR 60.1547b(d)(8)(vi) 

and corrects an unintended error in the 

March 2024 final rule. The EPA requests 

comment on the use of the proposed use 

of the 14-day sampling demonstration in 

40 CFR 60.1547b(d)(8)(iii) for air- and 

steam-assisted flares, particularly those 

at new sources subject to NHVcz and 

NHVdil requirements. 

With the alternative sampling 

provisions being proposed in 40 CFR 

60.5417b(d)(8)(iii) and the assessments 

outlined in 40 CFR 60.5417b(d)(8)(iv), 

we expect few facilities will have to 

install continuous monitoring systems. 

Since monitoring is necessary to ensure 

proper operation of these flares at new 

sources, and considering the monitoring 

options provided by the proposed 

revisions will afford sources additional 

flexibility when compared to the March 

2024 final rule, we are retaining the 

NHVcz and NHVdil requirements in 

NSPS subpart OOOOb. 

A provision to conduct monitoring for 

NHVcz and NHVdil at existing sources 

was included in the March 2024 final 

rule subpart OOOOc model rule in 

error. The EPA did not conduct Refinery 

MACT cost level monitoring for existing 

sources, and stated in the preamble to 

the March 2024 final rule that 

monitoring of NHVcz and NHVdil was 

not recommended as part of the 

Emission Guidelines for existing sources 

due to concerns about retrofitting 

existing flares to meet the 

requirements.44 The EPA is proposing to 

correct this inadvertent error by 

removing the language in the model rule 

to conduct monitoring of NHVcz and 

NHVdil at existing sources and 

specifying the model rule for these 

control systems is an NHV of 300 Btu/ 

scf in the vent gas. The EPA is 

requesting comment on the 

appropriateness of using an NHV of 300 

Btu/scf in the vent gas for air- and 

steam-assisted flares or enclosed 

combustion devices at existing sources 

for demonstrating compliance with the 

combustion efficiency requirements for 

these control devices. 

e. Miscellaneous Other Changes 

In addition to the proposed changes 

described above, the EPA is proposing 

to clarify that for the purposes of 

determining the hourly average of the 

NHV for continuously sampled (i.e., 

sampled continuously for 14 

consecutive days) inlet streams, the 

hourly average shall be determined on 

a block (and not a rolling) average. The 


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EPA is proposing this clarifying edit to 

ensure that all owners and operators are 

using the same averaging timeframe and 

it is not left up to interpretation as to 

whether the average should be a block 

average or a rolling average. Block 

averages are required for other averaging 

time periods in the March 2024 final 

rule and we consider this change to be 

warranted for consistency and clarity. 

The EPA also is proposing to clarify that 

the 14-day period for the continuous 

monitoring option shall be consecutive 

operating days. However, for manual 

grab sampling, the EPA is proposing to 

allow for breaks for weekends and 

holidays which may occur during the 

14-day representative grab sampling 

period, such that these do not have to 

be consecutive. Consecutive operating 

days are reasonable for continuous 

monitoring because these systems are 

present continuously. However, manual 

grab sample collection requires someone 

to be present at the site to collect 

samples each day, which, if required to 

be done on consecutive days, would 

require collection on weekends and 

potentially on holidays. The final 

requirements of the March 2024 final 

rule already allows for sampling beyond 

the 14 days if 28 samples cannot be 

collected during that time frame. 

Allowing additional flexibility for nonconsecutive operating day sampling can 

lengthen the time needed to collect 

samples and delay the conclusion of the 

NHV determination, but it does not 

reduce the number of samples required 

nor the representativeness of those 

samples. As such, we consider it 

reasonable to provide some flexibility in 

the grab sampling approach to allow 

twice daily sampling to determine the 

average NHV of the gas stream for 14 

operating days, with no sampling day to 

be spaced more than 3 operating days 

apart from the previous sampling day. 

Finally, the EPA is proposing to allow 

60 days for conducting 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 

(3 samples every 5 years) sampling 

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 

consider it a reasonable timeframe for 

installing necessary grab sampling 

systems to automatically collect samples 

at least once every 8 hours as provided 

in 40 CFR 60.5417b(d)(8)(ii)(D). 

Facilities would be required to collect 

grab samples every 8 hours until such 

time a continuous monitor can be 

installed, and installation of such a 

system requires more than 60 days. We 

request comment on the proposed 60- 

day compliance provision when a 5-year 

sampling event indicates the vent 

stream is not sufficiently above the 

required NHV. 

The EPA also is proposing a similar 

change to address compliance timing 

pending the re-evaluation that must 

occur after a process change that 

potentially reduces the NHV of the gas 

sent to an enclosed combustion device 

or flare. For the same reasons as stated 

above (i.e., for continuous monitoring 

which must occur after the results of 

periodic monitoring indicate the vent 

stream is not sufficiently above the 

required NHV), the EPA is proposing 

that continuous monitoring should 

commence within 60 days after the reevaluation indicates that the inlet gas 

stream does not meet the limits. The 

EPA also is proposing to clarify, for both 

periodic testing and re-evaluations 

which occur after a process change, that 

if the results of the grab sampling 

indicate that the vent stream is not 

sufficiently above the required NHV, 

continuous monitoring using a 

calorimeter, GC, MS, or continuous grab 

sampling (i.e., once every 8 hours) 

sampling must commence within the 

specified timeframe. 

Finally, the EPA is proposing 

revisions to the provisions in 40 CFR 

60.1547b(d)(8)(v), which include onetime assessments to be used in lieu of 

installing vent gas flow monitors and, in 

the case of assisted flares, assist gas flow 

monitors if certain provisions are met. 

While we finalized provisions to 

unassisted flares to conduct an initial 

determination to ensure the flare tip 

velocity is not exceeded under worstcase flow provisions, this requirement 

was not included in the March 2024 

final rule for air-assisted flares, even 

though the velocity limits apply. 

Therefore, we are proposing to add this 

maximum velocity assessment to the 

existing provisions in 40 CFR 

60.1547b(d)(8)(v)(D) and (E) for airassisted flares. This provision is not 

applicable to enclosed combustion 

devices. In reviewing these provisions, 

we also noted that there was no 

corresponding provision for steamassisted flares or enclosed combustion 

devices. This was an oversight in the 

March 2024 final rule and we are 

proposing new provisions at 40 CFR 

60.1547b(d)(8)(v)(F) similar to those for 

air-assisted devices that are specific to 

steam-assisted flares or enclosed 

combustion devices. These revisions are 

not needed in NSPS subpart OOOOc 

because these provisions are specific to 

evaluations for flares complying with an 

NHVcz or NHVdil parameter. The EPA 

requests comment on these proposed 

provisions to ensure compliance with 

the velocity operating limit and 

whether, for those devices that have 

conducted NHV demonstrations, the 

velocity limit used in the assessment 

should be based on the allowable 

velocity at the lowest NHV result from 

the demonstration rather than being 

based on the default of 18.3 meters/ 

second (60 feet/second). 

IV. How do these proposed 

amendments impact the 

implementation of EG OOOOc? 

The EPA’s proposed amendments 

discussed in section III (Summary and 

Rationale of Proposed Amendments to 

NSPS OOOOb and EG OOOOc) of this 

preamble in response to several 

petitions for reconsideration of aspects 

of the 2024 NSPS and EG final rule 

would not significantly impact the 

implementation of EG OOOOc or the 

State planning process. Based on the 

EPA’s reconsideration, the EPA is 

proposing amendments that revise two 

narrow aspects of the EG’s model rule: 

(1) The associated gas temporary flaring 

provisions for certain situations and (2) 

the NHV value continuous monitoring 

and alternative performance test 

(sampling demonstration) provisions for 

certain combustion control devices. The 

proposed amendments do not alter in 

any way the EPA’s identified best 

system of emission reduction (BSER) in 

the EG, the EPA’s identified degree of 

emissions limitation achievable via 

application of that BSER, the timeline 

for State plan submittal, or compliance 

timelines finalized under EG OOOOc. 

Any changes that a State or Tribe may 

make to their plan as a result of this 

proposed action will be minor such that 

the State or Tribe should be able to 

make such changes before their plans 

are required to be submitted for 

approval. 

As indicated in section I.A (Does this 

action apply to me?) of this preamble, 

the issuance of the CAA section 111(d) 

final EG does not impose binding 

requirements directly on existing 

sources. The EG (codified in 40 CFR 

part 60, subpart OOOOc) applies to 

States in the development, submittal, 

and implementation of State plans to 

establish performance standards to 

reduce emissions of GHGs from 

designated facilities that are existing 

sources on or before December 6, 2022. 

Further, under the TAR, eligible Tribes 


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may seek approval to implement a plan 

under CAA section 111(d) in a manner 

similar to a State, and Tribes are 

authorized under the TAR to develop 

and implement their own air quality 

programs, or portions thereof, under the 

CAA. 

V. Summary of Cost, Environmental, 

and Economic Impacts 

The proposed NSPS OOOOb and EG 

OOOOc discrete compliance 

requirement revisions included in this 

action and discussed in section III 

(Summary and Rationale of Proposed 

Amendments to NSPS OOOOb and EG 

OOOOc) of this preamble do not alter 

the substantive requirements of the final 

rule. The economic impacts and a 

qualitative discussion of the 

environmental impacts are presented in 

the memorandum titled Economic 

Impact Analysis for 2024 NSPS & EG 

Reconsideration. There are no other 

quantifiable environmental (e.g., air 

quality, water, waste), energy, or 

benefits beyond those already presented 

in accompanying Regulatory Impact 

Analysis (RIA) for the March 8, 2024, 

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 16820). 

As such, a new environmental justice 

(EJ) analysis was not conducted for this 

action. 

VI. Statutory and Executive Order 

Reviews 

Additional information about these 

statutes and Executive orders can be 

found at https://www.epa.gov/lawsregulations/laws-and-executive-orders. 

A. Executive Order 12866: Regulatory 

Planning and Review and Executive 

Order 14094: Modernizing Regulatory 

Review 

This action is a ‘‘significant regulatory 

action’’ as defined in Executive Order 

12866, as amended by Executive Order 

14094. Accordingly, the EPA submitted 

this action to the Office of Management 

and Budget (OMB) for Executive Order 

12866 review. Documentation of any 

changes made in response to the 

Executive Order 12866 review is 

available in the docket for this action 

(see memorandum titled Economic 

Impact Analysis for 2024 NSPS & EG 

Reconsideration). 

B. Paperwork Reduction Act (PRA) 

The information collection activities 

for NSPS OOOOb and EG OOOOc were 

previously approved by OMB under the 

PRA as of June 28, 2024. 

The EPA has revised the approved 

information collection request (ICR) to 

include small changes to incorporate 

EPA’s proposed recordkeeping and 

reporting to indicate whether the flare 

or enclosed combustion device receives 

inert gases or other streams which may 

lower the NHV of the combined stream 

as proposed in section III.B of this 

preamble. The EPA estimates an average 

of 48 respondents will be affected by 

this proposed requirement over the 

three-year period (2023–2025). The 

average annual burden for the 

recordkeeping and reporting 

requirements for these owners and 

operators is estimated at 83 personhours, with an average annual cost of 

$4,374 over the three-year period. 

The EPA also revised the approved 

ICR to include burden estimates for the 

maintenance of records that EPA is 

soliciting comment on. Specifically, the 

EPA includes burden estimates in the 

revised ICR for the records and annual 

reporting that would be required if EPA 

were to allow for the use of the 

associated gas extended flaring 

allowance under ‘‘exigent 

circumstances’’ as specified in section 

III.A of this preamble. The incremental 

increase in burden that would be 

associated with these recordkeeping and 

reporting requirements relative to the 

baseline is estimated at 2 hours per 

event annually over the three-year 

period (2024–2026) at an average annual 

cost of $120 per flaring event over the 

three-year period. The occurrence of 

flaring that could potentially be claimed 

due to ‘‘exigent circumstances’’ is 

unknown. However, we expect that a 

maximum of 16 percent of flaring events 

could potentially require an owner or 

operator to need to extend flaring 

beyond 48 hours due to ‘‘exigent 

circumstances’’. The burden associated 

with the two proposed reconsideration 

items under this action minimally affect 

the ICR burden estimated for 

compliance with EG OOOOc. The 

annual burden for this proposed 

additional collection of information for 

the States would be less than 1 percent. 

The approved ICR document that the 

EPA prepared was assigned OMB 

Control No. 2060–0721 and EPA ICR 

No. 2523.07. You can find a copy of the 

previously submitted ICR in Docket 

EPA–HQ–OAR–2021–0317. The revised 

ICR document that the EPA prepared for 

this reconsideration proposal has been 

assigned OMB Control No. 2060–0721 

and EPA ICR No. 2523.08. You can find 

a copy of the revised ICR in Docket 

EPA–HQ–OAR–2024–0358. 

C. Regulatory Flexibility Act (RFA) 

I certify that this action will not have 

a significant economic impact on a 

substantial number of small entities 

under the RFA. In making this 

determination, the EPA concludes that 

the impact of concern for this rule is any 

significant adverse economic impact on 

small entities and that the Agency is 

certifying that this rule will not have a 

significant economic impact on a 

substantial number of small entities 

because the rule has reduced net 

regulatory burden on the small entities 

subject to the rule. This action addresses 

two discrete compliance requirement 

aspects of NSPS OOOOb and the model 

rules within EG OOOOc based on 

petitions for reconsideration received on 

the March 2024 final rule requirements, 

providing additional flexibilities to 

entities subject to the NSPS 

requirements and to the model rules 

within EG OOOOc. We have therefore 

concluded that this action will have 

reduced net regulatory burden for all 

directly regulated small entities. For 

further details, see the document, 

Economic Impact Analysis for 2024 

NSPS & EG Reconsideration, in the 

docket. 

D. Unfunded Mandates Reform Act 

(UMRA) 

This action does not contain an 

unfunded mandate of $100 million or 

more as described in UMRA, 2 U.S.C. 

1531–1538, and does not significantly or 

uniquely affect small governments. This 

action imposes no enforceable duty on 

any State, local or Tribal governments or 

the private sector. This action addresses 

two discrete compliance requirement 

aspects of NSPS OOOOb and the model 

rules within EG OOOOc based on 

petitions for reconsideration received on 

the March 2024 final rule requirements. 

E. Executive Order 13132: Federalism 

This action does not have federalism 

implications. It will not have substantial 

direct effects on the States, on the 

relationship between the national 

government and the States, or on the 

distribution of power and 

responsibilities among the various 

levels of government. However, the EPA 

recognizes that States will have a 

substantial interest in this action and 

any future revisions to associated 

requirements. This action addresses two 

discrete compliance requirement 

aspects of NSPS OOOOb and the model 

rules within EG OOOOc based on 

petitions for reconsideration received on 

the March 2024 final rule requirements. 


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3752 Federal Register / Vol. 90, No. 9 / Wednesday, January 15, 2025 / Proposed Rules 

45 89 FR 17031. 

F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

This action does not have Tribal 

implications as specified in Executive 

Order 13175. This action addresses two 

discrete compliance requirement 

aspects of NSPS OOOOb and the model 

rules within EG OOOOc based on 

petitions for reconsideration received on 

the March 2024 final rule requirements. 

Thus, Executive Order 13175 does not 

apply to this action. 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

Risks and Safety Risks 

The EPA interprets Executive Order 

13045 as applying only to those 

regulatory actions that concern 

environmental health or safety risks that 

the EPA has reason to believe may 

disproportionately affect children, per 

the definition of ‘‘covered regulatory 

action’’ in section 2–202 of the 

Executive Order. The EPA believes that 

it is not practicable to assess whether an 

environmental health risk or safety risk 

affecting children may exist prior to this 

action. This action addresses two 

discrete compliance requirement 

aspects of NSPS OOOOb and the model 

rules within EG OOOOc based on 

petitions for reconsideration received on 

the March 2024 final rule requirements 

and does not result in any changes to 

the BSER of NSPS OOOOb or EG 

OOOOc. The EPA believes that the 

EPA’s Policy on Children’s Health also 

does not apply. 

H. Executive Order 13211: Actions 

Concerning Regulations That 

Significantly Affect Energy Supply, 

Distribution, or Use 

This action is not a ‘‘significant 

energy action’’ because it is not likely to 

have a significant adverse effect on the 

supply, distribution or use of energy. 

Further, we have concluded that this 

action is not likely to have any adverse 

energy effects because this action 

addresses two discrete compliance 

requirement aspects of NSPS OOOOb 

and the model rules within EG OOOOc 

based on petitions for reconsideration 

received on the March 2024 final rule 

requirements and does not result in any 

changes to the BSER of NSPS OOOOb 

or EG OOOOc. 

I. National Technology Transfer and 

Advancement Act (NTTAA) and 1 CFR 

Part 51 

This action does not involve any new 

technical standards. Therefore, the 

NTTAA does not apply. 

J. Executive Order 12898: Federal 

Actions To Address Environmental 

Justice in Minority Populations and 

Low-Income Populations and Executive 

Order 14096: Revitalizing Our Nation’s 

Commitment to Environmental Justice 

for All 

The EPA believes that it is not 

practicable to assess whether the human 

health or environmental conditions that 

exist prior to this action result in 

disproportionate and adverse effects on 

communities with EJ concerns. This 

action addresses two discrete 

compliance requirement aspects of 

NSPS OOOOb and the model rules 

within EG OOOOc based on petitions 

for reconsideration received on the 

March 2024 final rule requirements and 

does not result in any changes to the 

BSER of NSPS OOOOb or EG OOOOc. 

The EPA lacks specific and 

representative data on the frequency of 

temporary or emergency flaring, the 

number of sources flaring, or the length 

of time temporary flaring occurs. This 

data limitation prevents the EPA from 

estimating the impacts of an extension 

of allowed flaring. The March 2024 final 

rule describes how the rule will result 

in reductions in VOCs, which are an 

important precursor contributing to 

ground-level ozone formation in many 

regions of the country and reduce 

methane pollution that contributes to 

climate change, which itself has 

substantial and adverse impacts on EJ 

communities.45 The information 

supporting this Executive Order review 

is contained in the docket for this action 

(see memorandum titled Economic 

Impact Analysis for 2024 NSPS & EG 

Reconsideration). 

Michael S. Regan, 

Administrator. 

[FR Doc. 2024–31227 Filed 1–14–25; 8:45 am] 

BILLING CODE 6560–50–P 

DEPARTMENT OF HEALTH AND 

HUMAN SERVICES 

Administration for Children and 

Families 

45 CFR Parts 301, 302, 303, 304, 305, 

307, 308, 309, and 310 

RIN 0970–AC96 

Parentage Establishment in the Child 

Support Services Program; Withdrawal 

AGENCY: Administration for Children 

and Families (ACF), HHS. 

ACTION: Proposed rule; withdrawal. 

SUMMARY: This document withdraws a 

proposed rule that was published in the 

Federal Register on September 26, 2023. 

The proposed rule would have amended 

the Child Support Services Program to 

be inclusive of all family structures 

served by the child support services 

program. 

DATES: The Administration for Children 

and Families is withdrawing the 

proposed rule published September 26, 

2023 (88 FR 65928) as of January 15, 

2025. 

FOR FURTHER INFORMATION CONTACT: 

Kimberly Curtis, Division of Policy and 

Training, OCSS, telephone (202) 690– 

6614. Email inquiries to ocss.dpt@

acf.hhs.gov. Telecommunications Relay 

users may dial 711 first. 

SUPPLEMENTARY INFORMATION: The 

Administration for Children and 

Families (ACF) published a notice of 

proposed rulemaking (NPRM) related to 

the administration of the Child Support 

Services Program in the Federal 

Register on September 26, 2023 (88 FR 

65928). The Notice of Proposed 

Rulemaking (NPRM) proposed to define 

‘‘parentage’’ to mean the establishment 

of the legal parent-child relationship in 

accordance with the laws and 

procedures of the state or tribe. The 

NPRM also proposed to replace the 

gender-specific term ‘‘paternity’’ with 

the gender-neutral term ‘‘parentage’’ 

throughout Title 45 Chapter III of the 

Code of Federal Regulations, to be 

inclusive of all family structures served 

by the child support program. These 

proposed changes to Chapter III of the 

child support regulations recognized 

developments in state law regarding 

parentage establishment, including state 

laws allowing for establishment of 

parentage for children with same-sex 

parents. The proposed rulemaking 

provided states and tribes the option to 

expand their parentage establishment 

laws and procedures to include 

establishment of parentage for children 

of same-sex parents, and it reinforced 

that such services are eligible for Title 

IV–D matching funds. 

ACF does not intend to publish a final 

rule following the publication of this 

NPRM on September 26, 2023. In 

making this decision, we considered the 

complexity of the issues raised by some 

of the comments received and 

determined that, if the Department were 

to proceed with rulemaking on this 

topic, we would benefit from additional 

input from stakeholders to assure that 

assistance in obtaining support would 

be available under Title IV–D to all 

children for whom such assistance is 

requested, regardless of their family 

structure. Moreover, with the time 


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