Proposed Rule2025-00685
National Emission Standards for Hazardous Air Pollutants: Chemical Manufacturing Area Sources Technology Review
Primary source
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Published
January 22, 2025
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is proposing to establish a new area source category to address chemical manufacturing process units (CMPUs) using ethylene oxide (EtO). The EPA is proposing to list EtO in table 1 to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Chemical Manufacturing Area Sources (referred to as the CMAS NESHAP in this document) and to add EtO- specific requirements to the CMAS NESHAP. The EPA is also proposing to add a fenceline monitoring program for EtO. In addition, the EPA is proposing new requirements for pressure vessels and pressure relief devices (PRDs). This proposal also presents the results of the EPA's technology review of the CMAS NESHAP as required under the Clean Air Act (CAA). As part of this technology review, the EPA is proposing to add new leak detection and repair (LDAR) requirements to the CMAS NESHAP for equipment leaks in organic HAP service and heat exchange systems. The EPA is also proposing performance testing once every 5 years and to add provisions for electronic reporting. We estimate that the proposed amendments to the CMAS NESHAP, excluding the proposed EtO emission standards, would reduce hazardous air pollutant (HAP) emissions from emission sources by approximately 158 tons per year (tpy). Additionally, the proposed EtO emission standards are expected to reduce EtO emissions by approximately 4.6 tpy.
Full Text
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<title>Federal Register, Volume 90 Issue 13 (Wednesday, January 22, 2025)</title>
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[Federal Register Volume 90, Number 13 (Wednesday, January 22, 2025)]
[Proposed Rules]
[Pages 7942-7991]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-00685]
[[Page 7941]]
Vol. 90
Wednesday,
No. 13
January 22, 2025
Part IV
Environmental Protection Agency
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40 CFR Part 63
National Emission Standards for Hazardous Air Pollutants: Chemical
Manufacturing Area Sources Technology Review; Proposed Rule
Federal Register / Vol. 90 , No. 13 / Wednesday, January 22, 2025 /
Proposed Rules
[[Page 7942]]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 63
[EPA-HQ-OAR-2024-0303; FRL-7623-01-OAR]
RIN 2060-AU73
National Emission Standards for Hazardous Air Pollutants:
Chemical Manufacturing Area Sources Technology Review
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
establish a new area source category to address chemical manufacturing
process units (CMPUs) using ethylene oxide (EtO). The EPA is proposing
to list EtO in table 1 to the National Emission Standards for Hazardous
Air Pollutants (NESHAP) for Chemical Manufacturing Area Sources
(referred to as the CMAS NESHAP in this document) and to add EtO-
specific requirements to the CMAS NESHAP. The EPA is also proposing to
add a fenceline monitoring program for EtO. In addition, the EPA is
proposing new requirements for pressure vessels and pressure relief
devices (PRDs). This proposal also presents the results of the EPA's
technology review of the CMAS NESHAP as required under the Clean Air
Act (CAA). As part of this technology review, the EPA is proposing to
add new leak detection and repair (LDAR) requirements to the CMAS
NESHAP for equipment leaks in organic HAP service and heat exchange
systems. The EPA is also proposing performance testing once every 5
years and to add provisions for electronic reporting. We estimate that
the proposed amendments to the CMAS NESHAP, excluding the proposed EtO
emission standards, would reduce hazardous air pollutant (HAP)
emissions from emission sources by approximately 158 tons per year
(tpy). Additionally, the proposed EtO emission standards are expected
to reduce EtO emissions by approximately 4.6 tpy.
DATES:
Comments. Comments must be received on or before March 24, 2025.
Under the Paperwork Reduction Act (PRA), comments on the information
collection provisions are best assured of consideration if the Office
of Management and Budget (OMB) receives a copy of your comments on or
before February 21, 2025.
Public hearing: If anyone contacts us requesting a public hearing
on or before January 27, 2025 we will hold a virtual public hearing.
See SUPPLEMENTARY INFORMATION for information on requesting and
registering for a public hearing.
ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-
OAR-2024-0303, by any of the following methods:
<bullet> Federal eRulemaking Portal: <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>
(our preferred method). Follow the online instructions for submitting
comments.
<bullet> Email: <a href="/cdn-cgi/l/email-protection#f594d8949b91d887d8919a969e9081b5908594db929a83"><span class="__cf_email__" data-cfemail="6c0d410d0208411e4108030f0709182c091c0d420b031a">[email protected]</span></a>. Include Docket ID No. EPA-
HQ-OAR-2024-0303 in the subject line of the message.
<bullet> Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-
2024-0303.
<bullet> Mail: U.S. Environmental Protection Agency, EPA Docket
Center, Docket ID No. EPA-HQ-OAR-2024-0303, Mail Code 28221T, 1200
Pennsylvania Avenue NW, Washington, DC 20460.
<bullet> Hand/Courier Delivery: EPA Docket Center, WJC West
Building, Room 3334, 1301 Constitution Avenue NW, Washington, DC 20004.
The Docket Center's hours of operation are 8:30 a.m.-4:30 p.m., Monday-
Friday (except Federal Holidays).
Instructions: All submissions received must include the Docket ID
No. for this rulemaking. Comments received may be posted without change
to <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>, including any personal information
provided. For detailed instructions on sending comments and additional
information on the rulemaking process, see the SUPPLEMENTARY
INFORMATION section of this document.
FOR FURTHER INFORMATION CONTACT: For questions about this proposed
action, contact U.S. EPA, Attn: Mr. William Gallagher, Mail Drop: E143-
01, 109 T.W. Alexander Drive, P.O. Box 12055, RTP, North Carolina
27711; telephone number: (919) 541-2336; and email address:
<a href="/cdn-cgi/l/email-protection#9ef9fff2f2fff9f6fbecb0e9f7f2f2f7fff3defbeeffb0f9f1e8"><span class="__cf_email__" data-cfemail="ef888e83838e88878a9dc198868383868e82af8a9f8ec1888099">[email protected]</span></a>.
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 <a href="/cdn-cgi/l/email-protection#b0e3e0e0f4c0c5d2dcd9d3d8d5d1c2d9ded7f0d5c0d19ed7dfc6"><span class="__cf_email__" data-cfemail="9fcccfcfdbefeafdf3f6fcf7fafeedf6f1f8dffaeffeb1f8f0e9">[email protected]</span></a>. If requested,
the hearing will be held via virtual platform. The EPA will announce
the date of the hearing and further details at <a href="https://www.epa.gov/stationary-sources-air-pollution/chemical-manufacturing-area-sources-national-emission-standards">https://www.epa.gov/stationary-sources-air-pollution/chemical-manufacturing-area-sources-national-emission-standards</a>. 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 pre-registered speaker has
testified if there are no 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 <a href="https://www.epa.gov/stationary-sources-air-pollution/chemical-manufacturing-area-sources-national-emission-standards">https://www.epa.gov/stationary-sources-air-pollution/chemical-manufacturing-area-sources-national-emission-standards</a> or contact the public hearing team at (888) 372-8699 or by
email at <a href="/cdn-cgi/l/email-protection#06555656427673646a6f656e6367746f68614663766728616970"><span class="__cf_email__" data-cfemail="eebdbebeaa9e9b8c82878d868b8f9c878089ae8b9e8fc0898198">[email protected]</span></a>. The last day to pre-register to
speak at the hearing will be February 3, 2025. Prior to the hearing,
the EPA will post a general agenda that will list pre-registered
speakers at: <a href="https://www.epa.gov/stationary-sources-air-pollution/chemical-manufacturing-area-sources-national-emission-standards">https://www.epa.gov/stationary-sources-air-pollution/chemical-manufacturing-area-sources-national-emission-standards</a>.
The EPA will make every effort to follow the schedule as closely as
possible on the day of the hearing; however, please plan for the
hearings to run either ahead of schedule or behind schedule.
Each commenter will have 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 <a href="https://www.epa.gov/stationary-sources-air-pollution/chemical-manufacturing-area-sources-national-emission-standards">https://www.epa.gov/stationary-sources-air-pollution/chemical-manufacturing-area-sources-national-emission-standards</a>. 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 <a href="/cdn-cgi/l/email-protection#3f6c6f6f7b4f4a5d53565c575a5e4d5651587f5a4f5e11585049"><span class="__cf_email__" data-cfemail="a5f6f5f5e1d5d0c7c9ccc6cdc0c4d7cccbc2e5c0d5c48bc2cad3">[email protected]</span></a> to determine
if there are any updates. The EPA does not intend to publish a document
in the Federal Register announcing updates.
If you require the services of a translator or a special
accommodation such as audio description, please pre-register for the
hearing with the public hearing team and describe your needs by January
29, 2025. The EPA may not be able to arrange accommodations without
advanced notice.
Docket. The EPA has established a docket for this rulemaking under
Docket ID No. EPA-HQ-OAR-2024-0303. All
[[Page 7943]]
documents in the docket are listed in <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>.
Although listed, some information is not publicly available, e.g.,
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Certain other material, such as
copyrighted material, is not placed on the internet and will be
publicly available only in hard copy. With the exception of such
material, publicly available docket materials are available
electronically in <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>.
Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-
2024-0303. The EPA's policy is that all comments received will be
included in the public docket without change and may be made available
online at <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>, including any personal
information provided, unless the comment includes information claimed
to be CBI or other information whose disclosure is restricted by
statute. Do not submit electronically to <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>
any information that you consider to be CBI or other information whose
disclosure is restricted by statue. This type of information should be
submitted as discussed below.
The EPA may publish any comment received to its public docket.
Multimedia submissions (audio, video, etc.) must be accompanied by a
written comment. The written comment is considered the official comment
and should include discussion of all points you wish to make. The EPA
will generally not consider comments or comment contents located
outside of the primary submission (i.e., on the Web, cloud, or other
file sharing system). For additional submission methods, the full EPA
public comment policy, information about CBI or multimedia submissions,
and general guidance on making effective comments, please visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.
The <a href="https://www.regulations.gov/">https://www.regulations.gov/</a> website allows you to submit your
comment anonymously, which means the EPA will not know your identity or
contact information unless you provide it in the body of your comment.
If you send an email comment directly to the EPA without going through
<a href="https://www.regulations.gov/">https://www.regulations.gov/</a>, your email address will be automatically
captured and included as part of the comment that is placed in the
public docket and made available on the internet. If you submit an
electronic comment, the EPA recommends that you include your name and
other contact information in the body of your comment and with any
digital storage media you submit. If the EPA cannot read your comment
due to technical difficulties and cannot contact you for clarification,
the EPA may not be able to consider your comment. Electronic files
should not include special characters or any form of encryption and be
free of any defects or viruses. For additional information about the
EPA's public docket, visit the EPA Docket Center homepage at <a href="https://www.epa.gov/dockets">https://www.epa.gov/dockets</a>.
Submitting CBI. Do not submit information containing CBI to the EPA
through <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>. Clearly mark the part or all 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 Instructions above. If you submit any digital storage media
that does not contain CBI, mark the outside of the digital storage
media clearly that it does not contain CBI and note the docket ID.
Information not marked as CBI will be included in the public docket and
the EPA's electronic public docket without prior notice. Information
marked as CBI will not be disclosed except in accordance with
procedures set forth in 40 Code of Federal Regulations (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 <a href="/cdn-cgi/l/email-protection#aac5cbdbdad9c9c8c3eacfdacb84cdc5dc"><span class="__cf_email__" data-cfemail="137c7262636070717a537663723d747c65">[email protected]</span></a> and, as described above, should include
clear CBI markings and note the docket ID. If assistance is needed with
submitting large electronic files that exceed the file size limit for
email attachments, and if you do not have your own file sharing
service, please email <a href="/cdn-cgi/l/email-protection#ec838d9d9c9f8f8e85ac899c8dc28b839a"><span class="__cf_email__" data-cfemail="f49b9585848797969db4918495da939b82">[email protected]</span></a> to request a file transfer link.
If sending CBI information through the postal service, please send it
to the following address: U.S. EPA, Attn: OAQPS Document Control
Officer, Mail Drop: C404-02, 109 T.W. Alexander Drive, P.O. Box 12055,
RTP, North Carolina 27711, Attention Docket ID No. EPA-HQ-OAR-2024-
0303. 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 preamble the
use of ``we,'' ``us,'' or ``our'' is intended to refer to the EPA. We
use multiple acronyms and terms in this preamble. While this list may
not be exhaustive, to ease the reading of this preamble and for
reference purposes, the EPA defines the following terms and acronyms
here:
ACC American Chemistry Council
ACS American Community Survey
ADAF age-dependent adjustment factor
AFPM American Fuels and Petrochemical Manufacturers
APCD air pollution control device
API American Petroleum Institute
AVO audio, visual, and olfactory
BACT best available control technology
CAA Clean Air Act
CBI Confidential Business Information
CEDRI Compliance and Emissions Data Reporting Interface
CFR Code of Federal Regulations
CMAS Chemical Manufacturing Area Source(s)
CMPU chemical manufacturing process unit
CO carbon monoxide
CO<INF>2</INF> carbon dioxide
EAV equivalent annualized value
EFR external floating roof
EIS Emissions Inventory System
EJ environmental justice
EMACT Ethylene Production MACT
EPA Environmental Protection Agency
ERT Electronic Reporting Tool
EtO ethylene oxide
FID flame ionization detector
FR Federal Register
GACT generally available control technologies
HAP hazardous air pollutant(s)
HON Hazardous Organic NESHAP
HQ hazard quotient
HRVOC highly reactive volatile organic compound
ICR information collection request
IFR internal floating roof
IRIS Integrated Risk Information System
km kilometer(s)
kPa kilopascal(s)
LAER lowest achievable emission rate
lb pound(s)
lb/yr pound(s) per year
LDAR leak detection and repair
MACT maximum achievable control technology
MIR maximum individual lifetime [cancer] risk
MON Miscellaneous Organic Chemical Manufacturing NESHAP
MTVP maximum true vapor pressure
NAICS North American Industry Classification System
NATA National Air Toxics Assessment
NEI National Emissions Inventory
NESHAP national emission standards for hazardous air pollutants
NO<INF>X</INF> nitrogen oxides
N<INF>2</INF>O nitrous oxide
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NPRA National Petrochemical and Refiners Association
NSPS new source performance standards
OAQPS Office of Air Quality Planning and Standards
OAR Office of Air and Radiation
OLD Organic Liquids Distribution
OMB Office of Management and Budget
P&R I Group I Polymers and Resins
PDF portable document format
PEPO Polyether Polyols Production
PM<INF>2.5</INF> particulate matter 2.5
PMPU polyether polyol manufacturing process unit
ppmv parts per million by volume
ppmw parts per million by weight
PRA Paperwork Reduction Act
PRD pressure relief device
PV present value
RACT reasonably available control technology
RDL representative detection limit
RFA Regulatory Flexibility Act
RTR risk and technology review
SOCMI Synthetic Organic Chemical Manufacturing Industry
SO<INF>2</INF> sulfur dioxide
TCEQ Texas Commission on Environmental Quality
TOC total organic compounds
TOSHI target organ-specific hazard index
tpy tons per year
TRE total resource effectiveness
UMRA Unfunded Mandates Reform Act
U.S.C. United States Code
VCS voluntary consensus standards
VOC volatile organic compound(s)
[micro]g/m3 micrograms per cubic meter
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. Background
A. What is the statutory authority for this action?
B. What are the source categories and how does the current
NESHAP regulate HAP emissions?
C. What data collection activities were conducted to support
this action?
D. What other relevant background information and data are
available?
E. What are the results of the EPA's risk assessment?
III. Analytical Procedures and Decision-Making
A. How do we determine GACT?
B. How do we perform the technology review?
IV. Analytical Results and Proposed Decisions
A. What are our proposed decisions regarding standards
representing GACT for EtO emissions from CMAS, and what is the
rationale for those decisions?
B. What are our other proposed decisions regarding GACT
standards for CMAS, and what is the rationale for those decisions?
C. What are the results and proposed decisions based on our
technology review, and what is the rationale for those decisions?
D. What other actions are we proposing, and what is the
rationale for those actions?
E. What compliance dates are we proposing, and what is the
rationale for the proposed compliance dates?
V. Summary of Cost, Environmental, and Economic Impacts
A. What are the affected sources?
B. What are the air quality impacts?
C. What are the cost impacts?
D. What are the economic impacts?
E. What are the benefits?
F. What analysis of environmental justice did we conduct?
G. What analysis of children's environmental health did we
conduct?
VI. Request for Comments
VII. 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
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 categories that are the subject of this proposal are
Agricultural Chemicals and Pesticides Manufacturing, Chemical
Manufacturing with Ethylene Oxide, Cyclic Crude and Intermediate
Production, Industrial Inorganic Chemical Manufacturing, Industrial
Organic Chemical Manufacturing, Inorganic Pigments Manufacturing,
Miscellaneous Organic Chemical Manufacturing, Plastic Materials and
Resins Manufacturing, Pharmaceutical Production, and Synthetic Rubber
Manufacturing, regulated under 40 CFR part 63, subpart VVVVVV. The
North American Industry Classification System (NAICS) code for the
chemical manufacturing operations at any of the ten chemical
manufacturing area source (CMAS) categories is 325. This list of
categories and NAICS codes is not intended to be exhaustive, but rather
provides a guide for readers regarding the entities that this proposed
action is likely to affect. The proposed standards, once promulgated,
will be directly applicable to the affected sources. Federal, state,
local, and Tribal government entities would not be affected by this
proposed action. We listed Cyclic Crude and Intermediate Production,
Industrial Inorganic Chemical Manufacturing, Industrial Organic
Chemical Manufacturing, Plastic Materials and Resins Manufacturing, and
Synthetic Rubber Manufacturing as area source categories under CAA
section 112(c)(3) as part of the 1999 Integrated Urban Air Toxics
Strategy (64 FR 38721, July 19, 1999). On June 26, 2002, we amended the
area source category list by adding source categories, including
Agricultural Chemicals and Pesticides Manufacturing, Miscellaneous
Organic Chemical Manufacturing, and Pharmaceutical Production (67 FR
43112, 43113). On November 22, 2002, we added Inorganic Pigments
Manufacturing to the area source category list (67 FR 70427, 70428). In
this action, we are proposing to amend the area source category list by
adding Chemical Manufacturing with Ethylene Oxide (see section II.A.1
of this preamble). The other nine CMAS categories are discussed further
in section II.B of this preamble.
B. Where can I get a copy of this document and other related
information?
In addition to being available in the docket, an electronic copy of
this action is available on the internet. In accordance with 5 U.S.C.
553(b)(4), a summary of this rulemaking may be found at <a href="https://www.regulations.gov/">https://www.regulations.gov/</a>, Docket ID No. EPA-HQ-OAR-2024-0303. Following
signature by the EPA Administrator, the EPA will post a copy of this
proposed action at <a href="https://www.epa.gov/stationary-sources-air-pollution/chemical-manufacturing-area-sources-national-emission-standards">https://www.epa.gov/stationary-sources-air-pollution/chemical-manufacturing-area-sources-national-emission-standards</a>. 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 the CMAS NESHAP (40 CFR part 63, subpart
VVVVVV) proposed in this action is available in the docket (Docket ID
No. EPA-HQ-OAR-2024-0303). Following signature by the EPA
Administrator, the EPA also will post a copy of this document to
https://www.epa.gov/stationary-sources-air-pollution/chemical-
manufacturing-
[[Page 7945]]
area-sources-national-emission-standards.
II. Background
A. What is the statutory authority for this action?
The statutory authority for this action is provided by sections 112
and 301 of the CAA, as amended (42 U.S.C. 7401 et seq.). Several CAA
sections are relevant to this action as they specifically address
regulations of HAP emissions from area sources. Collectively, CAA
sections 112(c)(3), (d)(5), and (k)(3) are the basis of the Area Source
Program under the Urban Air Toxics Strategy, which provides the
framework for regulation of area sources under CAA section 112. Section
112(k)(3)(B) of the CAA requires the EPA to identify at least 30 HAP
that pose the greatest potential health threat in urban areas with a
primary goal of achieving a 75 percent reduction in cancer incidence
attributable to HAP emitted from stationary sources. As discussed in
the Integrated Urban Air Toxics Strategy (64 FR 38706, 38715, July 19,
1999), the EPA identified 30 HAP emitted from area sources that pose
the greatest potential health threat in urban areas, and these HAP are
commonly referred to as the ``30 urban HAP.'' CAA section 112(c)(3), in
turn, requires the EPA to list sufficient categories or subcategories
of area sources to ensure that area sources representing 90 percent of
the emissions of the 30 urban HAP are subject to regulation. The EPA
implemented these requirements through the Integrated Urban Air Toxics
Strategy by identifying and setting standards for categories of area
sources including the original nine CMAS categories that are addressed
in this action. This proposed action presents the required CAA
112(d)(6) technology review of the generally available control
technology (GACT) standards that the EPA established in 2009 \1\ for
the nine CMAS categories. In this action, we are also proposing to set
additional GACT standards for these categories. In addition to the
source categories and subcategories listed pursuant to CAA section
112(c)(3), CAA section 112(c)(5) provides the EPA discretion to
establish additional categories and subcategories of sources for
regulation if a threat of adverse effects to human health or the
environment is identified, per the criteria set forth in CAA section
112(c)(1) and (3). Pursuant to CAA section 112(c)(5), and consistent
with the requirements of CAA section 112(c)(3), this action also
proposes for regulation as part of the CMAS NESHAP a new area source
category, Chemical Manufacturing with Ethylene Oxide, and proposes GACT
standards for that new source category pursuant to CAA section
112(d)(5). Information about establishing a new area source category
for regulation pursuant to CAA section 112(c)(3) and (5), setting GACT
standards under CAA section 112(d)(5), and reviewing standards under
CAA section 112(d)(6) are provided in sections II.A.1, II.A.2, and
II.A.3 of this preamble, respectively.
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\1\ See 74 FR 56008, October 29, 2009.
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1. Listing An Additional Category Under CAA Section 112(c)(5)
CAA section 112(c)(5) provides that ``the Administrator may at any
time list additional categories and subcategories of sources of
hazardous air pollutants according to the same criteria for listing
applicable under [CAA section 112(c)(1) and (3)].'' CAA 112(c)(3), in
turn, provides in part that ``[t]he Administrator shall list . . . each
category or subcategory of area sources which the Administrator finds
presents a threat of adverse effects to human health or the environment
(by such sources individually or in the aggregate) warranting
regulation under this section.''
In 2016, the EPA updated the integrated risk information system
(IRIS) value for EtO to reflect new science related to the
pollutant.\2\ The updated IRIS value indicates that EtO is far more
carcinogenic than previously understood. In response to this update,
the EPA Office of Inspector General (OIG) released a report in 2021
using data from the 2014 National Air Toxics Assessment (NATA)
identifying facilities that could present lifetime cancer risks to the
public greater than or equal to 100-in-1 million.\3\ Several of these
facilities were area source chemical manufacturers. Based on the
revised carcinogenicity of EtO, the EPA decided to assess whether EtO
emissions from CMAS should be listed as an area source category
pursuant to CAA section 112(c)(3) and (5).
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\2\ The review is available at <a href="https://iris.epa.gov/static/pdfs/1025tr.pdf">https://iris.epa.gov/static/pdfs/1025tr.pdf</a>.
\3\ The report is available at <a href="https://www.epaoig.gov/sites/default/files/2021-05/documents/_epaoig_20210506-21-p-0129.pdf">https://www.epaoig.gov/sites/default/files/2021-05/documents/_epaoig_20210506-21-p-0129.pdf</a>.
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EtO is not one of the fifteen urban HAP currently regulated by the
CMAS NESHAP. Therefore, to fully assess whether a source category
including EtO emissions from area source chemical manufacturing
operations presents an adverse effect to human health or the
environment, facilities not currently part of the nine regulated source
categories were considered. To that end, we conducted a risk assessment
evaluating all reported HAP emissions from sources currently subject to
the CMAS NESHAP as well as sources that we believe would become subject
to the CMAS NESHAP if EtO were to be added to table 1 to 40 CFR part
63, subpart VVVVVV. The results of the risk assessment are summarized
in section II.E of this preamble. Based on the assessment, seven area
source chemical manufacturing facilities were estimated to have maximum
cancer risks greater than 100-in-1 million, all of which were driven
primarily (greater than 90 percent) by EtO emissions.\4\ The maximum
individual lifetime [cancer] risk (MIR) posed by the evaluated sources
is 800-in-1 million, driven by EtO emissions from process vents (97
percent).
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\4\ For additional details on these facilities, please see the
document titled Risk Assessment for the Chemical Manufacturing Area
Source (CMAS) Categories in Support of the 2025 Technology Review
for the Proposed Rule in the docket for this action.
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Given these estimates of risk, we propose that an area source
category associated with EtO emissions from area source chemical
manufacturers presents a threat of adverse effect on human health.
Accordingly, consistent with CAA section 112(c)(3) and (5), we are
proposing to list a new area source category. This area source
category, Chemical Manufacturing with Ethylene Oxide, would encompass
processes that produce a material or family of materials described by
NAICS code 325 where EtO is used as a feedstock, generated as a
byproduct, or is the material produced. This proposed source category
matches the scope of the nine source categories currently regulated by
the CMAS NESHAP, as described in section II.B of this preamble. Since
the existing CMAS NESHAP currently regulates these nine area source
categories collectively, we are proposing to also regulate the new
Chemical Manufacturing with Ethylene Oxide area source category under
the CMAS NESHAP at 40 CFR part 63, subpart VVVVVV. Alongside the
listing of this new area source category, the EPA is proposing to add
EtO specific applicability requirements at 40 CFR 63.11494(a)(2)(v) and
to list EtO in table 1 to 40 CFR part 63, subpart VVVVVV.
In conjunction with proposing to establish a new area source
category for Chemical Manufacturing with Ethylene Oxide, the EPA must
establish the level of control for the source category. Section II.A.2
provides details on our authority to establish GACT standards pursuant
to CAA section 112(d)(5) in lieu of maximum achievable control
[[Page 7946]]
technology (MACT) standards pursuant to CAA section 112(d)(2) and (3).
2. Alternative Standards for Area Sources Under CAA Section 112(d)(5)
Under CAA section 112(d)(5), the EPA may elect to promulgate
standards or requirements for area sources ``which provide for the use
of generally available control technologies or management practices by
such sources to reduce emissions of hazardous air pollutants.''
Additional information on GACT or management practices is found in the
Senate report on the legislation (Senate report Number 101-228,
December 20, 1989), which describes GACT as ``. . . methods, practices
and techniques which are commercially available and appropriate for
application by the sources in the category considering economic impacts
and the technical capabilities of the firms to operate and maintain the
emissions control systems.''
Consistent with the legislative history, we can consider costs and
economic impacts in determining GACT. Determining what constitutes GACT
involves considering the control technologies and management practices
that are generally available to the area sources in the source
category. As previously mentioned, GACT standards were set for the CMAS
categories in 2009. These GACT standards are discussed in section IV.C
of this preamble. See section II.B of this preamble for details about
each of the nine currently regulated CMAS categories.
In this action, we are proposing to set additional GACT standards
for the CMAS categories that would apply to certain emission sources
(i.e., equipment leaks, heat exchange systems, process vents, storage
tanks, wastewater, and transfer operations) associated with the
proposed area source category, Chemical Manufacturing with Ethylene
Oxide. In addition, we are proposing to set GACT standards for pressure
vessels and PRDs. The proposed GACT standards are discussed in sections
IV.A and IV.B of this preamble. In setting GACT, we always look to the
standards applicable to major sources in the same industrial sector to
determine if the control technologies and management practices are
transferable and generally available to area sources. In appropriate
circumstances, we may also consider technologies and practices at area
and major sources in similar categories to determine whether such
technologies and practices could be considered generally available for
the area source category at issue. In this case, the control
technologies and management practices for process units are
transferable because process units at major source chemical
manufacturing facilities are essentially no different than process
units at area source chemical manufacturing facilities excepting that
the former exceeds the major source HAP thresholds with respect to
emissions and the latter does not. Finally, as we have already noted,
in determining GACT for a particular area source category, we consider
the costs and economic impacts of available control technologies and
management practices on that category.
GACT differs from MACT in that cost can be considered in the first
instance when establishing a GACT standard. By contrast, when
establishing MACT standards pursuant to CAA section 112(d)(3), the EPA
must determine the average emission limitation achieved by the best
performing 12 percent of existing sources (or average emission
limitation achieved by the best performing 5 sources for existing
sources with fewer than 30 sources) and the emission limitation
achieved by the best controlled similar source for new sources, without
regard to cost.
As explained in greater detail in sections IV.A and IV.B of this
preamble, we determined that the GACT standards we are proposing for
sources emitting EtO (i.e., GACT standards for equipment leaks, heat
exchange systems, process vents, storage tanks, wastewater, and
transfer operations) located at CMAS, and the GACT standards we are
proposing for pressure vessels and PRDs at these same area sources,
should be similar, if not the same, as the major source standards that
were finalized in the Miscellaneous Organic Chemical Manufacturing
NESHAP (MON) and Hazardous Organic NESHAP (HON) pursuant to CAA section
112(d)(6) and (f) (see 85 FR 49084, August 12, 2020 and 89 FR 42932,
May 16, 2024, respectively). Our rationale for this is based on the
similarities between production processes, emission points, emissions,
and control technologies that are characteristic of both major and area
source chemical manufacturing facilities and considerations of cost.\5\
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\5\ The EPA also considers the costs and economic impacts of
available control technologies and management practices when
determining whether to revise a standard pursuant to section
112(d)(6); and the EPA also considers costs, energy, and other
relevant factors when determining whether to revise a standard in
the second step of the ample margin of safety analysis pursuant to
CAA section 112(f)(2)(A).
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We note that if standards for EtO are finalized, the EPA has
committed to the Office of the Inspector General (OIG) to assess the
risk posed from EtO emission sources subject to the CMAS NESHAP.
Specifically, the EPA committed to assess risk within four years of
promulgation of standards. At that time, the EPA would determine if it
is appropriate to review the standards prior to the date required by
CAA section 112(d)(6) (i.e., 8 years).\6\
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\6\ On June 1, 2022, the EPA, in response to the OIG's report
stating that EPA should revise the CMAS NESHAP to regulate EtO and
conduct a residual risk review, stated: ``. . . technology-based
standards for EtO have not yet been established for the CMAS source
category. Therefore, we plan to first evaluate EtO emissions from
the source category, and if EtO emissions present a public health
concern (i.e., by considering risk information), we will regulate
EtO in the CMAS rule . . . However, within four years of
promulgation (enough time to understand the level of emissions
remaining after implementation of new standards) of an any initial
EtO standards for CMAS, EPA would assess the risks from EtO
emissions from CMAS sources to inform us on whether an earlier
review date is appropriate.'' Refer to <a href="https://www.epaoig.gov/sites/default/files/documents/2022-06/_epaoig_21-P-0129_Agency_Response2.pdf">https://www.epaoig.gov/sites/default/files/documents/2022-06/_epaoig_21-P-0129_Agency_Response2.pdf</a> for additional details.
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3. Technology Review Under CAA Section 112(d)(6)
CAA section 112(d)(6) requires the EPA to review standards
promulgated under CAA section 112(d) and revise them ``as necessary
(taking into account developments in practices, processes, and control
technologies)'' no less often than every 8 years following promulgation
of those standards. This is referred to as a ``technology review'' and
is required for all standards established under CAA section 112(d)
including GACT standards that apply to area sources.
As previously mentioned, GACT standards were set for the CMAS
categories in 2009. Although in this action we are proposing additional
GACT standards for these categories, this proposed action also presents
the required CAA 112(d)(6) technology review of the 2009 GACT standards
for these source categories.
B. What are the source categories and how does the current NESHAP
regulate HAP emissions?
The EPA promulgated the CMAS NESHAP on October 29, 2009 (74 FR
56008), and codified the NESHAP at 40 CFR part 63, subpart VVVVVV. As
promulgated in 2009, and further amended on December 21, 2012 (77 FR
75740), the CMAS NESHAP regulates HAP emissions from chemical
manufacturing process units at an area source of HAP emissions if HAP
listed in table 1 to 40 CFR part 63, subpart VVVVVV are present in the
CMPU. A CMPU includes all process vessels, equipment, and activities
necessary to
[[Page 7947]]
operate a chemical manufacturing process that produces a material or a
family of materials described by NAICS code 325.\7\ A CMPU consists of
one or more unit operations and any associated recovery devices. A CMPU
also includes each storage tank, transfer operation, surge control
vessel, and bottoms receiver associated with the production of such
NAICS code 325 materials. The affected source is the facility-wide
collection of CMPUs and each heat exchange system and wastewater system
associated with a CMPU.
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\7\ Except for: (1) processes classified in NAICS Code 325222,
325314, 325413, or 325998; (2) processes subject to standards for
other listed area source categories in NAICS 325; (3) certain
fabricating operations; (4) manufacture of photographic film, paper,
and plate where material is coated or contains chemicals (but the
manufacture of the photographic chemicals is regulated); and (5)
manufacture of radioactive elements or isotopes, radium chloride,
radium luminous compounds, strontium, and uranium.
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The CMAS NESHAP currently applies to chemical manufacturing
operations at nine area source categories: (1) Agricultural Chemicals
and Pesticides Manufacturing; (2) Cyclic Crude and Intermediate
Production; (3) Industrial Inorganic Chemical Manufacturing; (4)
Industrial Organic Chemical Manufacturing; (5) Inorganic Pigments
Manufacturing; (6) Miscellaneous Organic Chemical Manufacturing; (7)
Plastic Materials and Resins Manufacturing; (8) Pharmaceutical
Production; and (9) Synthetic Rubber Manufacturing. These nine CMAS
categories encompass facilities that use as feedstocks,\8\ generate as
byproducts, or produce as products any of the following 15 HAP: 1,3-
butadiene; 1,3-dichloropropene; acetaldehyde; chloroform; ethylene
dichloride; hexachlorobenzene; methylene chloride; quinoline (these
eight HAP are referred to as the ``Table 1 \9\ organic HAP'');
compounds of arsenic, cadmium, chromium, lead, manganese, or nickel
(these six HAP are referred to as the ``Table 1 metal HAP''); or
hydrazine. In this preamble we refer to the nine source categories
collectively as CMAS categories (we are also proposing a tenth source
category as discussed in section II.A.1 of this preamble). Descriptions
of the nine source categories are as follows:
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\8\ Feedstocks are reactants, solvents, or any other additives
to the process.
\9\ ``Table 1'' refers to table 1 to 40 CFR part 63, subpart
VVVVVV.
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Agricultural Chemicals and Pesticides Manufacturing. The
agricultural chemicals and pesticides manufacturing source category is
designated by NAICS codes 325311 (nitrogenous fertilizer
manufacturing), 325312 (phosphatic fertilizer manufacturing), and
325320 (pesticide and other agricultural chemical manufacturing).
Products of this industry include nitrogenous and phosphatic fertilizer
materials including anhydrous ammonia, nitric acid, ammonium nitrate,
ammonium sulfate, urea, phosphoric acid, superphosphates, ammonium
phosphates, and calcium metaphosphates. The source category also
includes the formulation and preparation of ready-to-use agricultural
and household pest control chemicals from technical chemicals or
concentrates, the production of concentrates which require further
processing before use as agricultural pesticides, and the manufacturing
or formulating of other agricultural chemicals such as minor or trace
elements and soil conditioners.
Organic Chemical Production. The cyclic crude and intermediate
production, industrial organic chemical manufacturing, and
miscellaneous organic chemical manufacturing source categories are
discussed collectively because there is considerable overlap in the
NAICS codes that apply to these source categories. These source
categories include cellulosic organic fiber manufacturing as well as
other source categories that are designated by NAICS codes 32511
(petrochemical manufacturing), 325130 (synthetic dye and pigment
manufacturing), 32519 (other basic organic chemical manufacturing), and
3256 (soap, cleaning compound, and toilet preparation manufacturing).
The source category also includes organic gases designated by NAICS
code 325120 (industrial gas manufacturing), and it includes production
of chemicals such as explosives and photographic chemicals designated
by NAICS code 3259 (other chemical product and preparation
manufacturing). Raw materials for this industry include, for example,
refined petroleum chemicals, coal tars, and wood. The industry
manufactures a wide variety of final products as well as numerous
chemicals that are used as feedstocks to produce these final products
and products in other chemical manufacturing source categories.
Examples of types of products include solvents, organic dyes and
pigments, plasticizers, alcohols, detergents, and flavorings.
Industrial Inorganic Chemical Manufacturing. The industrial
inorganic chemical manufacturing source category includes manufacturing
of inorganic gases that are designated by NAICS code 325120 (industrial
gas manufacturing), manufacturing of inorganic dyes that are designated
by NAICS code 325130 (synthetic dye and pigment manufacturing), and
most manufacturing designated by NAICS code 32518 (other basic
inorganic chemical manufacturing). Exceptions to production designated
by NAICS code 32518 include carbon black and mercury cell chlor-alkali
production, which are separate source categories.
Inorganic Pigment Manufacturing. Inorganic pigments are part of
NAICS code 325130 (synthetic dye and pigment manufacturing). The
majority of inorganic pigments are oxides, sulfides, oxide hydroxides,
silicates, sulfates, or carbonates that normally consist of single
component particles. The inorganic pigment manufacturing processes can
generally be divided between those that use partial combustion and
those that use pure pyrolysis. Inorganic pigments generally are used to
impart colors to a variety of compounds. They may also impart
properties of rust inhibition, rigidity, and abrasion resistance.
Inorganic pigments are generally insoluble and remain unchanged
physically and chemically when mixed with a carrier. Pigment
manufacturers supply inorganic colors in a variety of forms including
powders, pastes, granules, slurries, and suspensions. Pigments are used
in the manufacture of paints and stains, printing inks, plastics,
synthetic textiles, paper, cosmetics, contact lenses, soaps,
detergents, wax, modeling clay, chalks, crayons, artists' colors,
concrete, masonry products, and ceramics.
Pharmaceutical Production. The pharmaceutical manufacturing source
category consists of chemical production operations that produce drugs
and medication. These operations include chemical synthesis (deriving a
drug's active ingredient) and chemical formulation (producing a drug in
its final form). The source category is designated by NAICS codes
325411 (medicinal and botanical manufacturing), 325412 (pharmaceutical
preparation manufacturing), and 325414 (biological product, except
diagnostic, manufacturing).
Plastic Materials and Resins Manufacturing. This source category is
designated by NAICS code 325211 (plastics material and resin
manufacturing). Examples of products in this source category include
epoxy resins, nylon resins, phenolic resins, polyesters, polyethylene
resins, and styrene resins. The source category does not include
polyvinyl chloride and copolymers production, which is a separate
source category.
Synthetic Rubber Manufacturing. The synthetic rubber manufacturing
source category is designated by NAICS code
[[Page 7948]]
325212 (synthetic rubber manufacturing). Facilities in this source
category manufacture synthetic rubber or vulcanizable elastomers by
polymerization or copolymerization. For this source category, an
elastomer is defined as a rubber-like material capable of
vulcanization, such as copolymers of butadiene and styrene, copolymers
of butadiene and acrylonitrile, polybutadienes, chloroprene rubbers,
and isobutylene-isoprene copolymers.
The HAP emission sources at facilities subject to the CMAS NESHAP
include process vents, storage tanks, equipment leaks, transfer
operations, and wastewater. Additionally, some facilities have cooling
towers or other heat exchangers. The GACT standards for CMAS include
emission standards in the form of management practices for each CMPU as
well as emission limits for certain emission sources including process
vents and storage tanks. The rule also establishes management practices
and other emission reduction requirements for wastewater systems and
heat exchange systems.
As of May 1, 2024, the EPA identified 251 facilities in operation
that are subject to the CMAS NESHAP. In addition, we are aware of 29
more facilities that would become subject to the CMAS NESHAP if EtO
were to be added to table 1 to the CMAS NESHAP, as proposed (see
section II.A.1 of this preamble) \10\. In this preamble, we referred to
all 280 of these facilities collectively as ``CMAS facilities.'' The
list of CMAS facilities located in the United States that are part of
the CMAS categories with processes subject to the CMAS NESHAP is
presented in the document titled List of Facilities Subject to the CMAS
NESHAP, which is available in the docket for this rulemaking.
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\10\ While 29 facilities were identified to become subject to
CMAS NESHAP if EtO were to be added to table 1 to 40 CFR part 63,
subpart VVVVVV, four of the 251 facilities currently subject to the
CMAS NESHAP also emit EtO. As such, in total, there are 33
facilities emitting EtO that may be impacted by this action.
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C. What data collection activities were conducted to support this
action?
1. Facility List
The EPA used several data sources to determine the facilities that
are subject to the CMAS NESHAP discussed in section II.B of this
preamble. We began with the facility list from the original rulemaking
for the CMAS NESHAP (74 FR 56008, October 29, 2009). This list was
supplemented with information from the Office of Enforcement and
Compliance Assurance's Enforcement and Compliance History Online tool
(<a href="https://echo.epa.gov">https://echo.epa.gov</a>) as well as other facility lists from the EPA's
recent chemical sector rulemakings (e.g., HON, MON, Organic Liquid
Distribution NESHAP (OLD), Ethylene Production MACT standards (EMACT
standards), and Polyether Polyols Production (PEPO) NESHAP).
We also collected and considered facility specific information from
the regions and/or states, if the information had not already been
captured by the previous steps. For example, we obtained title V air
permits from publicly available online state databases (where
available). In cases where an online database was incomplete or did not
exist, the EPA contacted the region and/or state for help in obtaining
the air permits or determining whether a facility was subject to the
CMAS NESHAP or may become subject to the CMAS NESHAP if EtO were to be
added to table 1 to 40 CFR part 63, subpart VVVVVV. The EPA also
conducted internet searches to determine the status of the facility
(e.g., whether the facility was still open, permanently closed, and/or
sold). Additional details about how the facility list was developed are
provided in the document titled List of Facilities Subject to the CMAS
NESHAP, which is available in the docket for this rulemaking.
The EPA solicits comment on the assumptions used to estimate the
number of facilities anticipated to be impacted by this action.
2. Emissions Inventory
For each facility subject to the CMAS NESHAP, we gathered emissions
data from the most recent version of the 2017 National Emissions
Inventory (NEI), published in January 2021. Apart from the 2020 NEI
(which was the first year of the COVID-19 pandemic), the 2017 NEI was
the most vetted and recent publicly available data set at the time EPA
began gathering information for this proposed rulemaking.\11\
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\11\ Refer to the 2017 NEI Technical Support Document for
detailed discussion on the types of review and augmentation
performed for 2017 NEI (<a href="https://www.epa.gov/sites/default/files/2021-02/documents/nei2017_tsd_full_jan2021.pdf">https://www.epa.gov/sites/default/files/2021-02/documents/nei2017_tsd_full_jan2021.pdf</a>).
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We consulted with state agencies, EPA regions, air permits, and
facilities to determine whether any EtO records in the CMAS emissions
inventory needed to be updated (beyond the 2017 NEI).\12\ This review
revealed that several facilities have either voluntarily implemented
EtO emission reduction measures since 2017 or implemented them due to
state or other requirements; therefore, we made amendments to these EtO
records to reflect the specific reduction measures. See appendix 1 of
the document titled Risk Assessment for the Chemical Manufacturing Area
Source (CMAS) Source Categories in Support of the 2025 Technology
Review for the Proposed Rule, which is available in the docket for this
rulemaking, for additional details on the analysis and methodology used
to develop the CMAS emissions inventory.
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\12\ For facilities that would become subject (or are already
subject) to the CMAS NESHAP if EtO were to be added to table 1 to 40
CFR part 63, subpart VVVVVV, as proposed.
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3. Other Data Collection Activities
To inform our reviews of the Agency's emission standards, we
reviewed the EPA's Reasonably Available Control Technology (RACT)/Best
Available Control Technology (BACT)/Lowest Achievable Emission Rate
(LAER) Clearinghouse and regulatory development efforts for similar
sources published after the CMAS NESHAP was developed.
In January 2022, the EPA issued requests, pursuant to CAA section
114, to collect information from HON facilities (nine being also
subject to the PEPO NESHAP) owned and operated by eight entities (i.e.,
corporations). This effort focused on gathering comprehensive
information about process equipment, control technologies, point and
fugitive emissions, and other aspects of facility operations.
Additionally, the EPA requested stack testing for certain emission
sources (e.g., pollutants, including EtO, for vent streams). Also, the
EPA required that facilities conduct fugitive emission testing (i.e.,
fenceline monitoring) for any of six specific HAP they emit: benzene;
1,3-butadiene; chloroprene; EtO; ethylene dichloride; and vinyl
chloride. Companies submitted responses (and follow-up responses) and
testing results to the EPA during the summer and fall of 2022. Given
that CMPU sources subject to the CMAS NESHAP can be similar to HON CMPU
sources and PEPO sources,\13\ the EPA used the collected information to
estimate environmental and cost impacts associated with some of the
regulatory options considered and reflected in this proposed action.
The information not claimed as CBI by respondents is provided in the
document titled Data Received from Information Collection Request for
[[Page 7949]]
Chemical Manufacturers, which is available in the docket for this
rulemaking.
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\13\ HON CMPUs and polyether polyol manufacturing process units
(PMPUs) associated with the PEPO NESHAP have similar processes as
CMAS CMPUs in that regardless of size, each of these process units
may include chemical manufacturing equipment, heat exchange systems,
process vents, storage tanks, transfer operations, and/or
wastewater.
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D. What other relevant background information and data are available?
In proposing these amendments, we relied on certain technical
reports and memoranda that the EPA developed for flares used as air
pollution control devices (APCDs) in the Petroleum Refinery Sector risk
and technology review (RTR) and new source performance standards (NSPS)
rulemaking (80 FR 75178, December 1, 2015). The Petroleum Refinery
Sector rulemaking docket is at Docket ID No. EPA-HQ-OAR-2010-0682. For
completeness of the rulemaking record for this action and for ease of
reference in finding these items in the publicly available Petroleum
Refinery Sector rulemaking docket, we are including the most relevant
flare-related technical support documents in the docket for this
proposed action (Docket ID No. EPA-HQ-OAR-2024-0303) and including a
list of all documents used to inform the 2015 flare provisions in the
Petroleum Refinery Sector RTR and NSPS rulemaking in the document
titled Clean Air Act Section 112(d)(5) GACT Standard Analysis for
Flares that Emit Ethylene Oxide and Section 112(d)(6) Technology Review
for Flares Associated with Chemical Manufacturing Process Units at Area
Sources Subject to the CMAS NESHAP, which is available in the docket
for this rulemaking.
We are also relying on data gathered to support the rulemakings for
the EMACT standards, HON, and MON, as well as memoranda documenting the
technology reviews for those processes. Many of the emission sources
for ethylene production facilities, HON facilities, and MON facilities
are similar to CMAS facilities, and the EPA analyzed several of the
control options for the CMAS NESHAP that the Agency also analyzed for
the rulemakings for the EMACT standards, HON, and MON. The memoranda
and background technical information can be found in the Ethylene
Production RTR rulemaking docket (Docket ID No. EPA-HQ-OAR-2017-0357),
the HON rulemaking docket (Docket ID No. EPA-HQ-OAR-2022-0730), and the
MON RTR rulemaking docket (Docket ID No. EPA-HQ-OAR-2018-0746).
Additional information related to the promulgation and subsequent
amendments of the CMAS NESHAP is available in Docket ID No. EPA-HQ-OAR-
2008-0334.
E. What are the results of the EPA's risk assessment?
As discussed in section II.A.1, the EPA conducted a human health
risk assessment to determine if EtO emissions from CMAS present a
threat of adverse effects to human health (e.g., a public health
concern) and therefore warrant regulation via the creation of a new
source category pursuant to CAA section 112(c)(3) and (5). Following
the update to the IRIS value for EtO, it became apparent that emissions
of EtO from CMAS could be posing a significant threat to public health.
The OIG released a report in 2021 that identified potential elevated
cancer risks due to EtO emissions from CMAS using data from the 2014
NATA.\14\ While the primary focus of the risk assessment was on EtO
emissions, consistent with other risk assessments for HAPs, we
estimated the MIR posed by emissions of HAP that are carcinogens from
each evaluated CMAS, the hazard index (HI) for chronic exposures to HAP
with the potential to cause noncancer health effects, and the hazard
quotient (HQ) for acute exposures to HAP with the potential to cause
noncancer health effects.\15\ This section summarizes the results of
those analyses.
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\14\ The report is available at <a href="https://www.epaoig.gov/sites/default/files/2021-05/documents/_epaoig_20210506-21-p-0129.pdf">https://www.epaoig.gov/sites/default/files/2021-05/documents/_epaoig_20210506-21-p-0129.pdf</a>.
\15\ The MIR is defined as the cancer risk associated with a
lifetime of exposure at the highest concentration of HAP where
people are likely to live. The HQ is the ratio of the potential HAP
exposure concentration to the noncancer dose-response value; the HI
is the sum of HQs for HAP.
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The EPA often conducts risk assessments at both the facility and
source category level when investigating human health concerns and uses
standard methodology for all risk assessments. However, we note that
this risk assessment was completed using the emissions inventory
described in section II.C.2 of this preamble. As such, there are
uncertainties with the results of the risk assessment engendered by the
uncertainties associated with the emissions inventory. However, given
the information available, we believe the risk assessment supports our
conclusion that these sources present a threat of an adverse impact on
human health. Additional details on the risk assessment and exact
methodology are presented in the document titled, Risk Assessment for
the Chemical Manufacturing Area Source (CMAS) Source Categories in
Support of the 2025 Technology Review for the Proposed Rule, which is
available in the docket for this rulemaking.
As discussed in section II.A.1 of this preamble, the MIR posed by
the evaluated sources is 800-in-1 million, driven primarily (greater
than 90 percent) by EtO emissions from process vents (97 percent).
Approximately 4.4 million people within 50 kilometers (km) of the
evaluated CMAS are estimated to have cancer risks above 1-in-1 million
and 3,600 people are estimated to have cancer risks above 100-in-1
million due to emissions from the sources. The people with risks above
100-in-1 million all reside within 10 km of the sources. The sources
are estimated to result in 0.4 additional cancer cases per year, or 1
cancer case every 2.5 years. Emissions from the evaluated CMAS drive
cancer risk attributable to whole facility emissions, such that the
risk posed by all HAP emissions from the facilities are generally the
same as the risk posed by the evaluated sources, except that emissions
from whole facility emissions increase the population with risk greater
than 1-in-1 million living within 50 km by 200,000 people.
The maximum chronic noncancer target organ-specific hazard index
(TOSHI) for the evaluated CMAS is estimated to be 3 (for respiratory
and immunological effects) at two facilities due to nickel compounds
emissions from process vents at one facility and equipment leaks and
fugitive emissions at the other facility. The same nickel emissions
also drive the estimated maximum facility-wide TOSHI of 3.
Approximately 1,500 people are estimated to have a TOSHI greater than 1
due to emissions from the evaluated CMAS.
The estimated reasonable worst-case off-site acute inhalation
exposures to emissions from the CMAS categories results in an estimated
maximum modeled acute noncancer HQ of 20 based on CalEPA's Chronic
Reference Exposure Level for acrolein. It is important to note that
when assessing acute inhalation exposures, the EPA makes conservative
assumptions about emission rates, meteorology, and exposure location.
We assume that an individual is present at the location of maximum
exposure at the exact same hour that peak emissions occur (using a
default factor of 10 from average actual annual emissions rates) and
the exact same hour the reasonable worst-case air dispersion conditions
(i.e., 99th percentile) occur. Together, these assumptions represent a
reasonable worst-case actual exposure scenario. In most cases, it is
unlikely that a person would be located at the point of maximum
exposure during the time when peak emissions and reasonable
[[Page 7950]]
worst-case air dispersion conditions occur simultaneously. Furthermore,
at the facility where the maximum HQ of 20 is estimated, the maximum
exposure is modeled to occur along the fenceline of the facility at a
location immediately surrounded by farmland making it more unlikely a
person would be located at that point at the exact hour the peak
emissions and the reasonable worst-case air dispersion conditions
occur.
We also conducted a community-based risk assessment for facilities
currently subject to the CMAS NESHAP or who would become subject to the
CMAS NESHAP with the proposal of the new area source category (see
section II.C.1 of this preamble for details on how the facility list
was developed). The goal of this assessment was to estimate cancer risk
from HAP emitted from all local stationary point sources for which we
have emissions data. We estimated the overall inhalation cancer risk
due to emissions from all stationary point sources impacting census
blocks within 10 km of the CMAS facilities. Specifically, we combined
the modeled impacts from category and non-category HAP sources at CMAS
facilities, as well as other stationary point source HAP emissions. The
results indicate that the community-level maximum individual cancer
risk is 5,000-in-1 million, with all risk attributable to chromium VI
emissions from an area source iron foundry. The Agency will investigate
these emissions to determine if follow-up action is necessary. We note
that the 2020 NEI data (the baseline for the community-level
assessment) for the facility driving the community-level MIR present an
anomalously high year of chromium VI emissions compared to other years.
Also, the default speciation of chromium emissions to chromium III and
chromium VI emissions done by the NEI is a conservative estimate of
emissions and may not be representative of the actual emissions. In
addition, we note that there is additional uncertainty in non-CMAS
categories emissions because they were not reviewed to the same extent
as emissions from CMAS facilities. Within 10 km, the population exposed
to cancer risks greater than 100-in-1 million from all nearby emissions
is approximately 5,600. For comparison, approximately 3,600 people have
cancer risks greater than 100-in-1 million due to emissions from the
evaluated CMAS NESHAP (see table 1 of this preamble).
After the controls proposed in this action are implemented for the
CMAS categories (see sections IV.A through IV.C of this preamble),
including the contribution from all non-EtO HAP, the maximum individual
cancer risk is estimated to be 100-in-1 million and no facilities are
estimated to pose cancer risk greater than 100-in-1 million. The number
of people living within 50 km of CMAS facilities with risk greater than
1-in-1 million due to emissions from the CMAS categories will decrease
from 4.4 million to 2.3 million. Chronic and acute noncancer risk is
not estimated to change, although our proposal to remove the 50 parts
per million by volume (ppmv) criteria as part of the definition of
``metal HAP process vent'' (see section IV.C.3 of this preamble) is
anticipated to reduce emissions of nickel that drive the chronic
noncancer risk. After implementation of the proposed controls, the
community-level maximum individual cancer risk will remain unchanged at
5,000-in-1 million. The population (within 10 km of CMAS facilities)
exposed to cancer risks greater than 100-in-1 million from all nearby
emissions will be reduced from 5,600 people to 1,900 people; a 66
percent reduction from the baseline. The increased cancer risk for most
of these 1,900 people is driven largely by emissions of chromium VI
from non-CMAS facilities within 10 km of CMAS facilities.
See table 1 of this preamble for a summary of the CMAS NESHAP
inhalation risk assessment results. We present the full results and
methods of the risk assessment in more detail, in the document titled
Risk Assessment for the Chemical Manufacturing Area Source (CMAS)
Source Categories in Support of the 2025 Technology Review for the
Proposed Rule, which is available in the docket for this rulemaking.
Table 1--Inhalation Cancer Risk Assessment Results for Communities Living Within 10 to 50 km of CMAS Facilities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Maximum Estimated population at increased risk Refined
individual of cancer maximum
Number of cancer risk ----------------------------------------- Estimated annual Maximum chronic screening
Risk assessment facilities (-in-1 cancer incidence noncancer TOSHI acute
\1\ million) >100-in-1 million >=1-in-1 million (cases per year) noncancer
\2\ HQ
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline (Pre-Control) Actual Emissions \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Category................. 248 800 3,600 (10 km)...... 2 million (10 km). 0.2 (10 km)....... 3 (respiratory, 20
3,600 (50 km)...... 4.4 million (50 0.4 (50 km)....... immunological).
km).
Facility-wide................... 279 800 3,600 (10 km)...... 2.2 million (10 0.2 (10 km)....... 3 (respiratory, \4\ --
3,600 (50 km)...... km). 0.4 (50 km)....... immunological).
4.6 million (50
km).
Community-based................. \5\ 9,932 5,000 5,600 (10 km)...... 8.6 million (10 0.8 (10 km)....... .................. ...........
km).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Post-Control Emissions
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Category................. 248 100 0.................. 1.3 million (10 0.1 (10 km)....... 3 (respiratory, 20
km). 0.2 (50 km)....... immunological).
2.3 million (50
km).
Facility-wide................... 279 100 0.................. 1.4 million (10 0.1 (10 km)....... 3 (respiratory, ...........
km). 0.2 (50 km)....... immunological).
2.5 million (50
km).
Community-based................. \3\ 9,932 5,000 1,900 (10 km)...... 8 million (10 km). 0.6 (10 km)....... .................. ...........
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Thirty-one (31) additional facilities were modeled for the CMAS whole-facility analysis compared to the CMAS categories analysis, because 279
facilities were originally identified as potentially subject to the CMAS NESHAP considering the current and proposed source categories based on permit
review and/or the facility's presence in the previous rulemaking's facility list. However, upon further review, only 248 of these 279 facilities were
identified as having emissions from the CMAS categories.
[[Page 7951]]
\2\ Maximum individual excess lifetime cancer risk due to HAP emissions.
\3\ Potential differences between actual emission levels and the maximum emissions allowable under EPA's standards (i.e., ``allowable emissions'') were
also evaluated for the CMAS categories. For the 248 CMAS facilities, there were 4 facilities with allowable emissions that differed from actual
emissions. These emissions were evaluated and it was determined there would be no appreciable difference in the risk results; therefore, the risk
results provided based on actual emissions also describe the risk assessment results based on allowable emissions.
\4\ ``--'' Indicates where an assessment was not conducted.
\5\ 9,653 nearby non-CMAS facilities in addition to the 279 facilities CMAS facilities evaluated.
III. Analytical Procedures and Decision-Making
A. How do we determine GACT?
As provided in CAA section 112(d)(5), we are proposing standards
representing GACT to regulate EtO emissions from equipment leaks, heat
exchange systems, process vents, storage tanks, wastewater, and
transfer operations located at CMAS. The statute does not set any
condition precedent for issuing standards under CAA section 112(d)(5)
other than that the area source category or subcategory at issue must
be one that EPA listed pursuant to CAA section 112(c), which is the
case here. In determining what constitutes GACT for this proposed rule,
we considered the control technologies and management practices that
are generally available to EtO emission sources at CMAS by examining
relevant data and information, including information collected from the
Synthetic Organic Chemical Manufacturing Industry (SOCMI) and PEPO
Production major source categories. We also considered the standards
for major chemical manufacturing sources subject to the MON and HON
(see 85 FR 49084, August 12, 2020, and 89 FR 42932, May 16, 2024,
respectively) to determine if the control technologies and work
practice standards for the major sources are generally available to
area sources as well. Finally, we considered the costs of available
control technologies and management practices on area sources.
From the information that we have collected to date in conjunction
with this rulemaking, which includes information about process
equipment, control technologies, point and fugitive emissions, and
other aspects of facility operations at major chemical manufacturing
sources, we know that area sources have the same types of emissions,
emission sources, and controls as major sources. Equipment leaks, heat
exchange systems, process vents, storage tanks, wastewater, and
transfer operations at major and area sources are using the same
control technologies. There are generally no discernible differences
between the processes at area and major chemical manufacturing sources
excepting size. In fact, major and area sources use similar, if not
identical, control technologies and practices to manage process
emissions. Therefore, the control technologies used by chemical
manufacturing major sources are generally available for CMAS.
B. How do we perform the technology review?
For the NESHAP area source GACT standard, our technology review
primarily focuses on the identification and evaluation of developments
in practices, processes, and control technologies that have occurred
since the standards were promulgated. Where we identify such
developments, we analyze their technical feasibility, estimated costs,
energy implications, and non-air environmental impacts. We also
consider the emission reductions associated with applying each
development. This analysis informs our decision of whether it is
``necessary'' to revise the emissions standards. In addition, we
consider the appropriateness of applying controls to new sources versus
retrofitting existing sources. For this exercise, we consider any of
the following to be a ``development'':
<bullet> Any add-on control technology or other equipment that was
not identified and considered during development of the original GACT
standards;
<bullet> Any improvements in add-on control technology or other
equipment (that were identified and considered during development of
the original GACT standards) that could result in additional emissions
reduction;
<bullet> Any work practice, management practice, or operational
procedure that was not identified or considered during development of
the original GACT standards;
<bullet> Any process change or pollution prevention alternative
that could be broadly applied to the industry and that was not
identified or considered during development of the original GACT
standards; and
<bullet> Any significant changes in the cost (including cost
effectiveness) of applying controls (including controls the EPA
considered during the development of the original GACT standards).
In addition to reviewing the practices, processes, and control
technologies that were considered at the time we originally developed
(or last updated) the CMAS NESHAP, we review a variety of data sources
in our investigation of potential practices, processes, or controls to
consider. See sections II.C and II.D of this preamble for information
on the specific data sources that were reviewed as part of the
technology review.
IV. Analytical Results and Proposed Decisions
A. What are our proposed decisions regarding standards representing
GACT for EtO emissions from CMAS, and what is the rationale for those
decisions?
As discussed in section II.A.1 of this preamble, the EPA is
proposing, pursuant to CAA section 112(c)(3) and (5), to create an area
source category describing chemical manufacturing operations using EtO.
Specifically, we are proposing at 40 CFR 63.11494(a)(2)(v) that you are
subject to the CMAS NESHAP if you own or operate a CMPU that is located
at an area source of HAP and EtO is used as a feedstock at an
individual concentration greater than 0.1 percent by weight; generated
as a byproduct and is present in the CMPU in any liquid stream (process
or waste) at a concentration of greater than or equal to 1 part per
million by weight (ppmw); generated as a byproduct and is present in
the CMPU in any continuous process vent or batch process vent at a
concentration greater than 1 ppmv; or is produced as a product of the
CMPU. The EPA is also proposing amendments to the CMAS NESHAP pursuant
to CAA section 112(d)(5) to include:
<bullet> New monitoring requirements for leaks from equipment in
EtO service;
<bullet> New monitoring requirements for leaks from heat exchange
systems in EtO service;
<bullet> A new emissions standard for batch and continuous process
vents in EtO service;
<bullet> A new emissions standard for storage tanks in EtO service;
<bullet> New control requirements for wastewater streams in EtO
service;
<bullet> Improved operational and monitoring requirements for
flares that emit EtO;
<bullet> A new fenceline monitoring standard related to EtO
emissions; and
<bullet> A requirement that any release event from a PRD in EtO
service is a deviation.
The data, analyses, results, and proposed decisions pursuant to CAA
section 112(d)(5) are presented for each
[[Page 7952]]
emission source in sections IV.A.1 through IV.A.8 of this preamble.
The EPA considers multiple factors in assessing the costs of
emission reductions.\16\ These factors include, but are not limited to,
total capital costs, total annual costs, cost effectiveness, and annual
costs compared to total annual revenues for ultimate owners of affected
facilities (i.e., costs to sales ratios). EtO is a highly potent
carcinogen and the cost-effectiveness numbers presented in sections
IV.A.1 through IV.A.8 of this preamble are within range of values that
we have determined to be cost effective for highly toxic HAP. For small
hard chromium electroplating, to provide an ample margin of safety to
protect public health, costs of $15,000 per pound (lb) ($30,000,000 per
ton) were finalized due to the toxicity of hexavalent chromium (see 77
FR 58227-8 and 77 FR 58239, September 19, 2012). EtO is similarly
highly toxic. The cost-effectiveness values presented in sections
IV.A.1 through IV.A.8 of this preamble are also within the range of
cost-effectiveness for control of EtO emissions that the EPA found
reasonable as part of the recent commercial sterilizers rulemaking (see
89 FR 24090, April 5, 2024). In this rulemaking, the EPA accepted costs
of up to $17,500,000/ton for existing sources in setting standards
under CAA section 112(d)(5). In addition, our established methodology
for assessing economic impacts of regulations indicates that the
potential for adverse economic impacts begins when a costs to sales
ratio exceeds three percent. According to our estimates, the
anticipated annual costs of the proposed emission control options
discussed below are well below three percent of annual sales for the
majority of the owners of potentially impacted EtO sources.
---------------------------------------------------------------------------
\16\ Natural Resources Defense Council v. EPA, 749 F.3d 1055,
1060 (DC Circ. April 18, 2014) (``Section 112 does not command the
EPA to use a particular form of cost analysis'').
---------------------------------------------------------------------------
1. Equipment Leaks in EtO Service
Emissions from equipment leaks occur in the form of gases or
liquids that escape to the atmosphere through connection points (e.g.,
threaded connectors) or through the moving parts of components such as
pumps and valves. EtO emissions are released from equipment leaks when
the components are associated with equipment that contain EtO (referred
to as equipment in EtO service). We provide details about equipment
leaks, including how the CMAS NESHAP regulates them, in our technology
review discussion (see section IV.C.1 of this preamble). For the GACT
standard analysis, we evaluated a single control option for leaks from
equipment in EtO service. The control option evaluated is identical to
the HON standards for leaks from equipment in EtO service and similar
(in terms of the technology, which is using EPA Method 21 instrument
monitoring) to the control options that we evaluated in the equipment
leaks technology review (see section IV.C.1 of this preamble). The EPA
recently added EtO-specific requirements into the HON for equipment in
EtO service that requires a more stringent monitoring frequency (i.e.,
monthly monitoring) and lower leak definitions (i.e., 100 ppmv or 500
ppmv) compared to monitoring for leaks from equipment not in EtO
service. In the HON, equipment in EtO service is equipment that
contains or contacts a fluid that is at least 0.1 percent by weight
EtO.
As such, given the transferability of major source work practice
standards to CMAS management practices due to the minimal differences
between performing instrument monitoring at a major source compared to
an area source, we evaluated the following option to represent GACT for
equipment ``in ethylene oxide service'' that are located at CMAS:
<bullet> Control Option 1 (if EtO was added to table 1 to 40 CFR
part 63, subpart VVVVVV): conduct monthly EPA Method 21 monitoring at a
leak definition of 100 ppmv for connectors and valves in EtO service
and 500 ppmv for pumps in EtO service.
We find this Control Option and the associated technologies to be
``generally available'' per the language of CAA section 112(d)(5).
While it was not proposed in the original CMAS rulemaking, an
instrument monitoring program similar to the MON was evaluated as part
of the original CMAS rulemaking in 2008. In addition, conducting EPA
Method 21 monitoring has been an option for the CMAS management
practices since promulgation (i.e., owners and operators may perform
EPA Method 21 monitoring in lieu of conducting audio, visual, and
olfactory (AVO) inspections). Also, the EPA is aware of facilities that
have already implemented instrument monitoring in some capacity as part
of complying with other regulatory requirements or as part of a
company-wide initiative to address EtO emissions. Therefore, we
conclude that instrument monitoring is generally available.
We estimated the cost and emissions reductions of Control Option 1
for 33 CMAS EtO facilities. Using background information available to
the EPA (including air permits and information received from various
EPA regional offices), it was determined that 10 CMAS EtO facilities
are already conducting instrument monitoring as part of an LDAR program
for their equipment in EtO service. Based on this, there are two types
of facilities for purposes of identifying their baseline LDAR program
for equipment in EtO service: those that do not have an LDAR program of
any kind; and those that already conduct EPA Method 21 instrument
monitoring. When evaluating the cost and emissions reductions for each
facility, we calculated the incremental cost and reductions to meet
Control Option 1 compared to a facility's baseline LDAR program. The
memorandum Clean Air Act Section 112(d)(5) GACT Standard Analysis for
Equipment Leaks that Emit Ethylene Oxide and Section 112(d)(6)
Technology Review for Equipment Leaks from Chemical Manufacturing
Process Units at Area Sources Subject to the CMAS NESHAP, which is
available in the docket for this rulemaking, summarizes the baseline
LDAR program for each of the 33 CMAS EtO facilities evaluated for this
control option and presents details on the methodologies used in this
analysis.
Table 2 of this preamble presents the nationwide impacts for
requiring owners and operators of equipment in EtO service to perform
EPA Method 21 monitoring in accordance with Control Option 1. Based on
the costs and emission reductions, we are proposing to revise the CMAS
NESHAP for equipment in EtO service to reflect Control Option 1
pursuant to CAA section 112(d)(5).
[[Page 7953]]
Table 2--Nationwide Emissions Reductions and Cost Impacts of Control Option 1 for Requiring EPA Method 21 Monitoring for Equipment in EtO Service at
Certain Facilities \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Total
Total annualized annualized EtO cost EtO cost
capital costs w/o costs with VOC emission EtO emission effectiveness w/ effectiveness
Control option investment recovery recovery reductions reductions o recovery with recovery
($) credits ($/ credits ($/ (tpy) (tpy) \2\ credits ($/ credits ($/
yr) yr) ton) ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
1......................................... 511,000 1,261,000 1,129,400 146 83 15,100 13,500
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Facilities that would either become subject to the CMAS NESHAP if EtO is added to table 1 to 40 CFR part 63, subpart VVVVVV, as proposed, or are
already subject to the CMAS NESHAP and emit EtO.
\2\ We note that EtO emission reductions from equipment leaks (and subsequent cost-effectiveness values for EtO from equipment leaks) differ from
reductions expected to occur from reported emissions inventories due to use of model plants, engineering assumptions made to estimate baseline
emissions, and uncertainties in how fugitive emissions may have been calculated for reported inventories compared to our model plants analysis (and
are documented in the memorandum).
The EPA is proposing to define equipment leaks ``in ethylene oxide
service'' at 40 CFR 63.11502(b), by reference to the HON (40 CFR
63.101). We are proposing Control Option 1 for equipment leaks in EtO
service at 40 CFR 63.11495(a)(7). These proposed requirements would
apply to all new and existing affected sources and specify that:
<bullet> All connectors in EtO service be monitored monthly at a
leak definition of 100 ppmv with no skip period, and delay of repair is
not allowed unless the equipment can be isolated such that it is no
longer in EtO service (see 40 CFR 63.174(a)(3), (b)(3)(vi), and (g)(3),
and 40 CFR 63.171(f)).
<bullet> All gas/vapor and light liquid valves in EtO service be
monitored monthly at a leak definition of 100 ppmv with no skip period,
and delay of repair is not allowed unless the equipment can be isolated
such that it is no longer in EtO service (see 40 CFR 63.168(b)(2)(iv)
and (d)(5), and 40 CFR 63.171(f)).
<bullet> All light liquid pumps in EtO service be monitored monthly
at a leak definition of 500 ppmv, and delay of repair is not allowed
unless the equipment can be isolated such that it is no longer in EtO
service (see 40 CFR 63.163(a)(1)(iii), (b)(2)(iv), (c)(4), and (e)(7),
and 40 CFR 63.171(f)).
2. Heat Exchange Systems in EtO Service
Emissions of EtO from heat exchange systems occur when a heat
exchanger's internal tubing material corrodes or cracks, allowing some
process fluids to mix or become entrained with the cooling water.
Pollutants (e.g., EtO) in the process fluids may subsequently be
released from the cooling water into the atmosphere when the water is
exposed to air (e.g., in a cooling tower for closed-loop systems or
trenches/ponds in a once-through system). We provide more details about
heat exchange systems, including how the CMAS NESHAP regulates them, in
our technology review discussion (see section IV.C.2 of this preamble).
Our CMAS heat exchange system technology review (see section IV.C.2 of
this preamble) identified use of the Modified El Paso Method as a
development in practice for heat exchange systems with a cooling water
flow rate equal to or greater than 8,000 gallons per minute (gpm).
Specifically, we identified the following control option for heat
exchange systems: quarterly monitoring with the Modified El Paso
Method, using a leak action level defined as a total strippable
hydrocarbon concentration (as methane) in the stripping gas of 6.2
ppmv. This option would also require repairing a leak no later than 45
days after first identifying the leak, delay of repair within 120 days
(except within no more than 30 days where a total strippable
hydrocarbon concentration (as methane) in the stripping gas of 62 ppmv
or higher is found), and re-monitoring at the monitoring location where
the leak was identified to ensure that any leaks found are fixed.
To assess what GACT standards may be appropriate if EtO is added to
table 1 to 40 CFR part 63, subpart VVVVVV, we reviewed other
rulemakings to identify the level of control required for heat exchange
systems emitting EtO. As part of that review, we identified one rule
requiring monitoring of heat exchange systems ``in ethylene oxide
service.'' The EPA recently added EtO-specific requirements into the
HON for heat exchange systems in EtO service that require more
stringent monitoring frequency (weekly instead of quarterly) and repair
of leaks within 15 days from the sampling date (in lieu of the current
45-day repair requirement after receiving results of monitoring
indicating a leak) (see 89 FR 42932, May 16, 2024). Additionally, delay
of repair is not allowed unless there is no longer an active EtO leak
once the heat exchange system is isolated and not in EtO service. A
heat exchange system in EtO service means any heat exchange system in a
process that cools process fluids (liquid or gas) that are 0.1 percent
or greater by weight of EtO. If knowledge exists that suggests EtO
could be present in a heat exchange system, then the heat exchange
system is considered to be ``in ethylene oxide service'' unless the
procedures specified in the HON at 40 CFR 63.109 are performed to
demonstrate that the heat exchange system does not meet the definition
of being ``in ethylene oxide service.'' Examples of information that
could suggest EtO could be present in a heat exchange system include
calculations based on safety data sheets, material balances, process
stoichiometry, or previous test results provided the results are still
relevant to the current operating conditions.
Given the EtO specific requirements in the HON for heat exchange
systems in EtO service and minimal operational differences between heat
exchange systems operating at SOCMI and CMAS facilities, we evaluated
the following options in the selection of GACT for all heat exchange
systems ``in ethylene oxide service'' that are located at CMAS:
<bullet> Control Option 1: quarterly monitoring (after an initial
six months of monthly monitoring) with the Modified El Paso Method,
using a leak action level defined as a total strippable hydrocarbon
concentration (as methane) in the stripping gas of 6.2 ppmv; reduce the
allowed amount of repair time from 45 days after finding a leak to 15
days from the sampling date; and prohibit delay of repair.
<bullet> Control Option 2: same as Control Option 1, except monthly
monitoring with the Modified El Paso Method instead of quarterly
monitoring.
<bullet> Control Option 3: same as Control Option 1, except weekly
monitoring with the Modified El Paso Method instead of quarterly
monitoring. This option is required in the HON.
The Modified El Paso Method is required and in use by sources
regulated under other rulemakings including, but not limited to the
MON, the HON, and the Petroleum Refineries NESHAP. The method works via
air stripping and use of a flame ionization detector (FID), both of
which are well understood
[[Page 7954]]
technologies in the chemical manufacturing sector and have been in use
for decades. Given the widespread use of the fundamental technologies
and method in other, similar chemical manufacturing facilities, we
consider use of the Modified El Paso Method to be ``generally
available.''
We estimated the impacts of these Control Options using information
from the original CMAS rulemaking.\17\ We estimated that 27 of the 33
facilities that either would become subject to the CMAS NESHAP if EtO
is added to table 1 to 40 CFR part 63, subpart VVVVVV or that are
already subject to the CMAS NESHAP and emit EtO would be affected by
Control Options 1 through 3; and we assumed each affected facility does
not currently have an LDAR program for monitoring their cooling water.
As part of our analysis, we also assumed all facilities monitoring
quarterly for two or less heat exchange systems would elect to contract
out the Modified El Paso monitoring (instead of purchasing a stripping
column and FID analyzer and performing the monitoring in-house);
however, facilities monitoring monthly or weekly would elect to
purchase a stripping column and FID analyzer and perform in-house
monitoring due to logistics. In addition, we assumed repairs could be
performed by plugging a specific heat exchanger tube, and if a heat
exchanger is leaking to the extent that it needs to be replaced, then
it is effectively at the end of its useful life. Therefore, we
determined that the cost of replacing a heat exchanger is an
operational cost that would be incurred by the facility because of
routine maintenance and equipment replacement, and it is not
attributable to the Control Options.
---------------------------------------------------------------------------
\17\ EPA, 2008. Control Options and Impacts for Cooling Tower
Control Measures Chemical Manufacturing Area Source Standards.
September 5, 2008. Docket ID No. EPA-HQ-OAR-2008-0334-0003; and EPA,
2009. Update to the Control Options and Impacts for Heat Exchange
System Control Measures for Promulgation Chemical Manufacturing Area
Source Standards. May 5, 2009. Docket ID No. EPA-HQ-OAR-2008-0334-
0081.
---------------------------------------------------------------------------
Table 3 of this preamble presents the nationwide impacts for
requiring owners and operators of heat exchange systems in EtO service
to use the Modified El Paso Method and repair leaks of total strippable
hydrocarbon concentration (as methane) in accordance with Control
Options 1 through 3. See the document titled Clean Air Act Section
112(d)(5) GACT Standard Analysis for Heat Exchange Systems that Emit
Ethylene Oxide and Section 112(d)(6) Technology Review for Heat
Exchange Systems Associated with Chemical Manufacturing Process Units
at Area Sources Subject to the CMAS NESHAP, which is available in the
docket for this rulemaking, for details on the assumptions and
methodologies used in this analysis.
While all Control Options were identified as cost effective based
on values accepted as part of other recent rulemakings regulating EtO
emissions (see 89 FR 24090, April 5, 2024, for the commercial
sterilizer rulemaking), the potency of EtO as a carcinogen, and
historic cost-effectiveness values accepted for highly toxic HAP (such
as hexavalent chromium), there are no records in the emissions
inventory from heat exchangers in EtO service. We note that leaks from
heat exchange systems handling EtO can still occur, even if there are
no specific emissions records in the inventory. This absence of records
is likely because most facilities emitting EtO have not been required
to monitor leaks in their heat exchange systems. Consequently, the
impacts associated with controlling these emissions are less certain
due to the lack of records. In addition, there are concerns that
monthly or weekly monitoring of heat exchangers in EtO service would be
significantly more burdensome for area sources than major sources.
Major sources may have additional capital and personnel bandwidth to
accommodate installation and operation of a stripping column and lab
equipment (such as a gas chromatograph/mass spectroscopy unit)
necessary for in-house analysis compared to area sources who may not
have previously been subject to any monitoring of heat exchange
systems. As such, based on the costs, emissions reductions, and
uncertainties, we are proposing that Control Option 1 represents GACT
for heat exchange systems in EtO service. However, we are soliciting
comments and data on whether more frequent monitoring (i.e., Control
Options 2 and 3) would be appropriate for CMAS considering the proposed
addition of EtO to table 1 to 40 CFR part 63, subpart VVVVVV.
Table 3--Nationwide Emissions Reductions and Cost Impacts of Control Options 1 Through 3 for Requiring the Modified El Paso Method for Heat Exchange Systems in EtO Service at Certain
Facilities \1\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total Total
Total annualized annualized EtO cost EtO cost EtO Incremental
capital costs w/o costs with VOC emission EtO emission effectiveness w/ effectiveness cost effectiveness
Control option investment recovery recovery reductions reductions o recovery with recovery with recovery
($) credits ($/ credits ($/ (tpy) (tpy) credits ($/ton) credits ($/ton) credits (from
yr) yr) option 1) ($/ton)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1................................................................ 122,000 157,000 117,900 43.4 24.8 6,300 4,700 ..................
2................................................................ 122,000 359,400 319,500 44.3 25.3 14,200 12,500 388,500
3................................................................ 122,000 1,371,500 1,331,300 44.7 25.5 52,300 52,200 1,688,800
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\1\ Facilities that would either become subject to the CMAS NESHAP if EtO is added to table 1 to 40 CFR part 63, subpart VVVVVV, as proposed, or are already subject to the CMAS NESHAP and emit
EtO.
The EPA is proposing to define a heat exchange system ``in ethylene
oxide service'' at 40 CFR 63.11502(b), by reference to the HON (40 CFR
63.101). We are proposing Control Option 1 at 40 CFR 63.11499(e) and
item 2 of table 8 to the CMAS NESHAP, by reference to the HON (40 CFR
63.104(a), (f) through (i), and (k)), to specify quarterly monitoring
(after an initial six months of monthly monitoring) for leaks for all
new and existing affected sources with heat exchange systems in EtO
service using the Modified El Paso Method, and if a leak is found, we
are proposing owners and operators must repair the leak to below the
applicable leak action level as soon as practicable, but no later than
15 days after the sample was collected with no delay of repair allowed
(see 40 CFR 63.104(h)(6)).
3. Process Vents and Storage Tanks in EtO Service
Emissions of EtO can occur from several types of gas streams
associated with CMAS processes, such as distillation columns,
evaporator vents, and vacuum operations, as well as during vapor
displacements and heating losses. CMAS storage tanks are used to store
liquid and gaseous feedstocks for use in a process, as well as to store
[[Page 7955]]
liquid and gaseous products from a process. EtO is typically stored
under pressure as a liquified gas but may also be found in small
amounts in atmospheric storage tanks storing liquid products that are
formed with EtO as a reactant in their production. Typical emissions
from atmospheric storage tanks occur from working and breathing losses
while pressure vessels are considered closed systems and, if properly
maintained and operated, should have virtually no emissions. In some
instances, pressurized vessels also could use a blanket of inert gas,
most often nitrogen, to maintain a non-decomposable vapor space, and
continuous purge of vapor space from non-loading operations could also
lead to emissions from storage tanks. We provide details about process
vents and storage tanks, including how the CMAS NESHAP regulates them,
in our technology review discussion (see sections IV.C.3 and IV.C.4 of
this preamble, respectively).
To assess what GACT standards may be appropriate, we reviewed other
rulemakings to identify the level of control required for process vents
and storage vessels emitting EtO. As part of that review, we identified
two rules requiring stringent control of emissions from vents and
process tanks ``in ethylene oxide service.'' The EPA recently added
EtO-specific requirements into the MON and HON for process vents and
storage vessels in EtO service (see 85 FR 49084, August 12, 2020, and
89 FR 42932, May 16, 2024, respectively). We note that the MON and HON
use the term ``storage vessel'' in lieu of ``storage tank'' which is
used in the CMAS NESHAP. According to the MON and HON, a process vent
in EtO service is a process vent that contains a concentration of
greater than or equal to 1 ppmv undiluted EtO when uncontrolled, and
when all process vents within the process are combined, the sum of
uncontrolled EtO emissions are greater than or equal to 5 pounds per
year (lb/yr) (2.27 kilogram per year, kg/yr). A storage vessel in EtO
service means a storage vessel of any capacity and vapor pressure
storing a liquid that is at least 0.1 percent by weight of EtO. The
EtO-specific standards established for the Miscellaneous Organic
Chemical Manufacturing and SOCMI source categories are as follows:
<bullet> Requirements that owners and operators must reduce
emissions of EtO from process vents in EtO service by either: (1)
venting emissions through a closed vent system to a control device that
reduces EtO by greater than or equal to 99.9 percent by weight, to a
concentration less than 1 ppmv for each process vent, or to less than 5
lb/yr for all combined process vents per CMPU; or (2) venting emissions
through a closed vent system to a flare meeting certain new operating
and monitoring requirements for flares; and
<bullet> Requirements that owners and operators must reduce
emissions of EtO from storage tanks in EtO service by either: (1)
venting emissions through a closed vent system to a control device that
reduces EtO by greater than or equal to 99.9 percent by weight or to a
concentration less than 1 ppmv for each storage tank vent; or (2)
venting emissions through a closed vent system to a flare meeting
certain new operating and monitoring requirements for flares.
Given the EtO specific requirements in the MON and HON for process
vents and storage vessels in EtO service and minimal operational
differences between an APCD controlling emissions from process vents or
storage vessels/tanks at MON, SOCMI, and CMAS facilities, we evaluated
a Control Option to represent GACT for process vents and storage tanks
that are ``in ethylene oxide service'' that would require owners and
operators at certain CMAS (i.e., facilities that would either become
subject to the CMAS NESHAP if EtO is added to table 1 to 40 CFR part
63, subpart VVVVVV, as proposed, or are already subject to the CMAS
NESHAP and emit EtO) to reduce emissions of EtO by 99.9 percent from
process vents and storage tanks that are ``in ethylene oxide service''
as defined by the MON and HON (i.e., Control Option 1). Our evaluation
considered the use of a thermal oxidizer achieving a 99.9 percent
reduction of EtO emissions to control emissions from process vents and
storage tanks in EtO service, as it is common for the same control
device to control emissions from both emission sources at chemical
plants. Control Option 1 reflects the EtO-specific requirements in the
MON and HON for process vents and storage vessels in EtO service;
therefore, it would apply to process vents in which the uncontrolled,
undiluted EtO emissions from all process vents in a CMPU are greater
than or equal to 5 lb/yr and the concentration of the uncontrolled,
undiluted stream is greater than or equal to 1 ppmv. This Control
Option would also apply to storage tanks of any capacity and vapor
pressure storing a liquid that is at least 0.1 percent by weight of
EtO.
We find this Control Option to be ``generally available'' per the
language of CAA section 112(d)(5). Control devices include a wide array
of potential technologies and so a facility may use whatever methods
are available to achieve the 99.9 percent by weight reduction in EtO
emissions. Thermal oxidizers, which we assumed will be installed by
facilities needing to meet the proposed standards, are used to control
emissions from process vents and storage tanks at sources regulated
under other rulemakings including, but not limited to, the MON and the
HON and have been in use in industry for decades. In addition, the CMAS
NESHAP already allows for the venting of emissions through a closed
vent system to a flare for both process vents and storage tanks. Given
the widespread use of a readily available control technology such as a
thermal oxidizer in other, similar chemical manufacturing facilities,
we consider this Control Option of proposing a 99.9 percent by weight
reduction of EtO emissions from process vents and storage tanks to be
``generally available.''
To determine which emission points at facilities would need
additional control of EtO emissions, we reviewed the CMAS emissions
inventory data (see section II.C.2 of this preamble). For each process
vent and storage tank emission point record with EtO emissions in the
CMAS emissions inventory, we determined whether it was controlled by a
non-flare combustion device, a non-combustion control device, a non-
combustion control device able to achieve 99.9 percent emissions
reduction, or was uncontrolled. There are no process vent or storage
tank emission point records associated with a non-flare combustion
device; however, for emission point records that are controlled by a
non-combustion control device, our impacts analyses assumed that none
of the facilities with existing non-combustion controls would be able
to achieve 99.9 percent control of EtO, unless a stack test or data
provided by a state agency confirmed otherwise. Therefore, we treated
non-combustion control devices unable to achieve 99.9 percent control
and uncontrolled emission point records in the same manner and assumed
that each would need to be controlled by a thermal oxidizer. Some
facilities that would need to install a thermal oxidizer to control EtO
have multiple process vent and/or storage tank emission points with EtO
emissions. Rather than costing out multiple thermal oxidizers for these
facilities, we assumed they would combine the streams together and
install a single thermal oxidizer (to control all EtO emissions), as is
commonly done at chemical plants. We also recognize that some emission
points could possibly achieve a 99.9 percent reduction in EtO emissions
by upgrading or installing a
[[Page 7956]]
new scrubber system instead of a new thermal oxidizer; and upgrading or
installing a new scrubber system would likely cost less than installing
a new thermal oxidizer. However, for simplicity, we only evaluated the
use of a thermal oxidizer to meet the Control Option because using
thermal oxidizers is common for controlling emissions from both process
vents and storage tanks in EtO service at chemical plants. Ultimately,
we determined that seven facilities would be impacted by Control Option
1 to reduce emissions of EtO by 99.9 percent from process vents and
storage tanks that are ``in ethylene oxide service'' as defined by the
MON and HON (1 of these 7 facilities is already subject to the CMAS
NESHAP and the remaining 6 facilities would become subject to the CMAS
NESHAP if EtO is added to table 1 to 40 CFR part 63, subpart VVVVVV, as
proposed). We estimated costs to install a thermal oxidizer using the
EPA's control cost template.\18\ Table 4 of this preamble presents the
nationwide impacts of Control Option 1, requiring owners and operators
to reduce emissions of EtO by 99.9 percent from process vents and
storage tanks that are ``in ethylene oxide service'' as defined by the
MON and HON. See the document titled Clean Air Act Section 112(d)(5)
GACT Standard Analysis for Process Vents and Storage Tanks that Emit
Ethylene Oxide and Section 112(d)(6) Technology Review for Process
Vents and Storage Tanks Associated with Chemical Manufacturing Process
Units at Area Sources Subject to the CMAS NESHAP, which is available in
the docket for this rulemaking, for details on the assumptions and
methodologies used in this analysis. Based on the costs and emission
reductions for Control Option 1, we are proposing to revise the CMAS
NESHAP for process vents and storage tanks in EtO service to reflect
Control Option 1 pursuant to CAA section 112(d)(5). The cost
effectiveness of this Control Option is within the range of values that
have been accepted in other recent rulemakings regulating EtO emissions
such as the commercial sterilizer rulemaking (see 89 FR 24090, April 5,
2024) \19\ and is within the range of historic cost-effectiveness
values that have been accepted for highly toxic HAP (such as hexavalent
chromium).\20\ EtO is similarly toxic due to its potency as a
carcinogen. As such, we find that this Control Option is cost
effective.
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\18\ Refer to the file ``Incinerators and Oxidizers Calculation
Spreadsheet (note: updated on 1/16/2018) (xlsm)'' which follows the
methodology from the sixth edition of the EPA Air Pollution Control
Cost Manual and can be found at the following website: <a href="https://www.epa.gov/economic-and-cost-analysis-air-pollution-regulations/cost-reports-and-guidance-air-pollution">https://www.epa.gov/economic-and-cost-analysis-air-pollution-regulations/cost-reports-and-guidance-air-pollution</a>.
\19\ The EPA finalized EtO emissions standards in the RTR for
sterilization facilities with costs estimated to be as much as
$17,500,000 per ton EtO.
\20\ For small hard chromium electroplating, to provide an ample
margin of safety, the EPA finalized a requirement with a cost
effectiveness of $15,000 per lb ($30,000,000 per ton) (see 77 FR
58227-8 and FR 77 58239, September 19, 2012).
Table 4--Nationwide Emissions Reductions and Cost Impacts of Control Option 1 for Requiring 99.9 Percent Control
of Process Vents and Storage Tanks in EtO Service at Certain Facilities \1\
----------------------------------------------------------------------------------------------------------------
EtO cost
Control option Total capital Total annualized EtO emission effectiveness ($/
investment ($) costs ($/yr) reductions (tpy) ton)
----------------------------------------------------------------------------------------------------------------
1................................... 1,395,000 2,126,000 1.1 1,933,000
----------------------------------------------------------------------------------------------------------------
\1\ Facilities that would either become subject to the CMAS NESHAP if EtO is added to table 1 to 40 CFR part 63,
subpart VVVVVV, as proposed, or are already subject to the CMAS NESHAP and emit EtO.
The EPA is proposing to define a process vent ``in ethylene oxide
service'' at 40 CFR 63.11502(b), by reference to the HON (40 CFR
63.101). We are proposing Control Option 1 for all new and existing
affected sources with process vents in EtO service at 40 CFR
63.11496(j), item 4 of table 2 to the CMAS NESHAP (for batch process
vents), and item 4 of table 3 to the CMAS NESHAP (for continuous
process vents), by reference to the HON. These proposed requirements
specify that owners and operators of process vents in EtO service must
reduce emissions of EtO by venting emissions through a closed vent
system to a flare in accordance with the requirements in 40 CFR 63.108
and 40 CFR 63.124 (see section IV.A.6 of this preamble for additional
details regarding our proposed requirements for flares that emit EtO),
or to a control device that reduces EtO by greater than or equal to
99.9 percent by weight, or to a concentration less than 1 ppmv for each
process vent or to less than 5 lb/yr for all combined process vents
within the process in accordance with the requirements in 40 CFR
63.124.
The EPA is proposing to define a storage tank (vessel) ``in
ethylene oxide service'' at 40 CFR 63.11502(b), by reference to the HON
(40 CFR 63.101). We are also proposing that the exemption for ``tanks
storing organic liquids containing HAP only as impurities'' listed in
the definition of ``storage tank'' at 40 CFR 63.11502(b) does not apply
for storage tanks in EtO service. We are also proposing Control Option
1 for storage tanks in EtO service at 40 CFR 63.11497(e) and item 5 of
table 5 to the CMAS NESHAP, by reference to the HON. These proposed
requirements specify that owners and operators of storage tanks in EtO
service must reduce emissions of EtO by venting emissions through a
closed vent system to a flare in accordance with the requirements in 40
CFR 63.108 and 40 CFR 63.124 (see section IV.A.6 of this preamble for
additional details regarding our proposed requirements for flares that
emit EtO), or to a control device that reduces EtO by greater than or
equal to 99.9 percent by weight, or to a concentration less than 1 ppmv
for each storage tank vent in accordance with the requirements in 40
CFR 63.124.
In addition, given that 40 CFR 63.124 requires owners and operators
to comply with the HON leak inspection requirements in 40 CFR 63.148
and the delay of repair provisions associated with these inspection
requirements (i.e., 40 CFR 63.148(e)) rely on a definition for
``shutdown'' that does not include batch processes, we are also
proposing to substitute the use of ``shutdown'' with language at 40 CFR
63.11496(j)(5)(iv) and 40 CFR 63.11497(e)(5)(iv) to accommodate both
continuous and batch processes. We are proposing that for 40 CFR
63.148(e), the term ``shutdown'' for a continuous operation, means the
cessation of the unit operation for any purpose. Shutdown begins with
the initiation of steps as described in a written standard operating
procedure or shutdown plan to cease normal/stable operation (e.g.,
reducing or immediately stopping feed). For batch operations, we are
proposing that for 40 CFR 63.148(e), the term ``shutdown'' means the
cessation of a
[[Page 7957]]
batch operation except shutdown does not apply to cessation of batch
operations at the end of a campaign or between batches within a
campaign when the steps taken to cease operation are normal operations.
Finally, we are also proposing to remove the option to allow use of
a design evaluation in lieu of performance testing to demonstrate
compliance for controlling process vents and storage tanks that are in
EtO service. In addition, owners or operators that choose to control
emissions with a non-flare control device would be required to conduct
an initial performance test on each control device in EtO service to
verify performance at the required level of control, and would also be
required to conduct periodic performance testing on non-flare control
devices in EtO service every 5 years (see proposed 40 CFR 63.11496(j)
and 40 CFR 63.11497(e) by reference to 40 CFR 63.124).
4. Wastewater in EtO Service
EtO is emitted into the air from wastewater collection, storage,
and treatment systems that are uncovered or open to the atmosphere
through volatilization of the compound at the liquid surface. The rate
of volatilization is related directly to the speed of the air flow over
the water surface. We provide more details about wastewater streams,
including how the CMAS NESHAP regulates them, in our technology review
discussion (see section IV.C.5 of this preamble).
To assess what GACT standards may be appropriate for wastewater in
EtO service, we reviewed other rulemakings to identify the level of
control required for wastewater emitting EtO. As part of that review,
we identified one rule requiring control of emissions from wastewater
``in ethylene oxide service.'' In the HON rulemaking, the EPA recently
added EtO-specific requirements for wastewater streams in EtO service
(see 89 FR 42932, May 16, 2024). These standards require owners and
operators to manage and treat existing and new wastewater streams with
total annual average concentration of EtO greater than or equal to 1
ppmw at any flow rate. As such, we evaluated a Control Option to
represent GACT for wastewater streams that are ``in ethylene oxide
service'' that would require owners and operators at certain CMAS
(those that would either become subject to the CMAS NESHAP if EtO is
added to table 1 to 40 CFR part 63, subpart VVVVVV, as proposed, or are
already subject to the CMAS NESHAP and emit EtO) to comply with the HON
Group 1 wastewater requirements for wastewater streams that are ``in
ethylene oxide service'' as defined by the HON (i.e., Control Option
1).
The HON specifies performance standards for treatment processes
managing Group 1 wastewater streams including performance standards for
open or closed biological treatment systems or a design steam stripper
with vent control. For APCDs (e.g., thermal oxidizers) used to control
emissions from collection system components, steam strippers, or closed
biological treatment, the HON provides owners or operators several
compliance options, including a 95 percent destruction efficiency
standard, a 20 ppmv outlet concentration standard, or design
specifications for temperature and residence time. Given the EtO
specific requirements in the HON at 40 CFR 63.138(b)(3) and (c)(3) for
wastewater streams in EtO service to reduce, by removal or destruction,
the concentration of EtO to a level less than 1 ppmw and minimal
operational differences between controlling emissions from HON CMPUs
and CMAS CMPUs, we evaluated the use of steam stripping to comply with
Control Option 1. While we acknowledge EtO can be biodegraded, the
compound is not on table 37 to subpart G of the HON suggesting that it
is not a readily biodegradable compound when using a biological
treatment method, and EtO would need to be stripped out of the
wastewater to meet the standard at 40 CFR 63.138(b)(3) and (c)(3).
Therefore, we evaluated Control Option 1 using a steam stripper
achieving a 98 percent reduction of EtO emissions (based on the
fraction removed (Fr) value of EtO \21\ in table 9 to subpart G of the
HON).
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\21\ The Fr is the fraction of a HAP that is stripped from
wastewater and is an indicator of the extent to which a HAP is
effectively removed during the steam stripping process, which for
EtO is 98 percent.
---------------------------------------------------------------------------
We find Control Option 1 to be ``generally available'' per the
language of CAA section 112(d)(5). Steam strippers are used to control
emissions from wastewater streams at sources regulated under other
rulemakings including, but not limited to, the MON and the HON. In
addition, steam stripping was evaluated as part of the original
rulemaking and is currently a method of compliance for controlling
certain CMPU wastewater streams. Given the widespread use of this
control technology in other, similar chemical manufacturing facilities,
and current applicability of the technology to certain CMAS wastewater
streams, we consider this Control Option of proposing the use of steam
strippers to control EtO emissions from wastewater to be ``generally
available.''
We reviewed the CMAS emissions inventory data (see section II.C.2
of this preamble) as well as air permits and determined that there are
4 CMAS facilities that have wastewater processes that use and emit EtO
and therefore would be impacted by Control Option 1. To evaluate the
impacts of requiring these facilities to meet Control Option 1, we used
PEPO-specific wastewater data submitted in response to the EPA's 2022
CAA section 114 request (see section II.C.3 of this preamble). We used
the PEPO-specific wastewater data rather than HON-specific data because
for EtO processes, CMAS CMPUs are more like PEPO PMPUs given that both
CMAS CMPUs and PEPO PMPUs use EtO as a reactant (often in batch
reactions to make a product), whereas HON CMPUs produce EtO and are
continuous. In addition, we removed all PEPO-specific wastewater data
that could not be representative of an area source (based on the amount
of HAP emissions that could potentially be emitted to the atmosphere
from the wastewater streams); and therefore, not representative of a
CMAS facility. We estimated costs to install a steam stripper using the
cost algorithm for wastewater stripper steam requirements used for the
development of the HON.\22\ Table 5 of this preamble presents the
nationwide impacts of Control Option 1, requiring owners and operators
to manage and treat existing and new wastewater streams with total
annual average concentration of EtO greater than or equal to 1 ppmw at
any flow rate in accordance with HON Group 1 wastewater requirements.
See the document titled Clean Air Act Section 112(d)(5) GACT Standard
Analysis for Wastewater Streams that Emit Ethylene Oxide and Clean Air
Act Section 112(d)(6) Technology Review for Wastewater Systems
Associated with Chemical Manufacturing Process Units at Area Sources
Subject to the CMAS NESHAP, which is available in the docket for this
rulemaking, for details on the assumptions and methodologies used in
this analysis. Based on the costs and emission reductions for Control
Option 1, we are proposing to revise the CMAS NESHAP for wastewater in
EtO service to reflect Control Option 1 pursuant to CAA section
112(d)(5). The
[[Page 7958]]
cost effectiveness of this Control Option is within the range of values
that have been accepted in other recent rulemakings regulating EtO
emissions, such as the commercial sterilizer rulemaking (see 89 FR
24090, April 5, 2024) \23\, and is within the range of historic cost-
effectiveness values that have been accepted for highly toxic HAP (such
as hexavalent chromium).\24\ EtO is similarly toxic due to its potency
as a carcinogen. As such, we find that this Control Option is cost
effective.
---------------------------------------------------------------------------
\22\ EPA, 1992a. Hazardous Air Pollutant Emissions from Process
Units in the Synthetic Organic Chemical Manufacturing Industry--
Background Information for Proposed Standards, Volume 1B: Control
Technologies. EPA-453/D-92-016b. November 1992; and EPA, 1992b.
Hazardous Air Pollutant Emissions from Process Units in the
Synthetic Organic Chemical Manufacturing Industry--Background
Information for Proposed Standards, Volume 1C: Model Emission
Sources. EPA-453/D-92-016c. November 1992.
\23\ See footnote 19.
\24\ See footnote 20.
Table 5--Nationwide Emissions Reductions and Cost Impacts of Control Option 1 for Requiring Control of
Wastewater in EtO Service at Certain Facilities \1\
----------------------------------------------------------------------------------------------------------------
EtO emission EtO cost
Control option Total capital Total annualized reductions (tpy) effectiveness ($/
investment ($) costs ($/yr) \2\ ton)
----------------------------------------------------------------------------------------------------------------
1................................... 12,899,400 5,471,300 8.3 659,200
----------------------------------------------------------------------------------------------------------------
\1\ Facilities that would either become subject to the CMAS NESHAP if EtO is added to table 1 to 40 CFR part 63,
subpart VVVVVV, as proposed, or are already subject to the CMAS NESHAP and emit EtO.
\2\ We note that EtO emission reductions from wastewater (and subsequent cost-effectiveness values for EtO from
wastewater) differ from reductions expected to occur from reported emissions inventories due to use of model
plants, engineering assumptions made to estimate baseline emissions, and uncertainties in how fugitive
emissions may have been calculated for reported inventories compared to our model plants analysis (and are
documented in the memorandum).
The EPA is proposing to define a wastewater stream ``in ethylene
oxide service'' at 40 CFR 63.11502(b), by reference to the HON (40 CFR
63.101). We are proposing Control Option 1 for all new and existing
affected sources with wastewater streams in EtO service at 40 CFR
63.11498(c) and item 3 of table 6 to the CMAS NESHAP, by reference to
the HON. These proposed requirements specify that owners and operators
of wastewater in EtO service must reduce, by removal or destruction,
the concentration of ethylene oxide in existing and new wastewater
streams (i.e., wastewater streams with total annual average
concentration of EtO greater than or equal to 1 ppmw at any flow rate)
to a level less than 1 ppmw as determined by the procedures specified
in Sec. 63.145(b) and in accordance with the Group 1 wastewater stream
requirements of Sec. Sec. 63.133 through 63.148 and the requirements
referenced therein. Additionally, we are aware that some chemical
manufacturing facilities dispose of certain wastewater streams that
contain EtO by adding those wastewaters to the cooling water of their
heat exchange systems, rather than considering those EtO-containing
streams to be potential sources of wastewater. To eliminate these types
of EtO emissions from wastewater being injected into heat exchange
systems, we are also proposing to prohibit owners and operators from
injecting water into or disposing of water through any heat exchange
system in a CMPU meeting the conditions of 40 CFR 63.11494 if the water
contains any amount of EtO, has been in contact with any process stream
containing EtO, or the water is considered wastewater as defined in 40
CFR 63.11502 (see proposed 40 CFR 63.11495(b)(4) and items 1.c and 2 of
table 8 to the CMAS NESHAP).
5. Standards for Transfer Operations That Emit EtO
The EPA includes transfer operations as part of the equipment
collection that makes up a CMPU (see 40 CFR 63.11494(b)). According to
the CMAS NESHAP, transfer operations involve loading liquid containing
organic HAP into tank trucks and rail cars from a transfer rack. This
does not include loading into other containers like cans, drums, and
totes.
The CMAS NESHAP defines a transfer rack as the system used to load
organic liquids into tank trucks and railcars at a single location.
This system includes all necessary loading arms, pumps, meters, shutoff
valves, relief valves, and other piping and equipment. Transfer
equipment that do not share common piping, valves, and other equipment
are considered separate transfer racks.
The CMAS NESHAP regulates transfer operations through specific
management practices. According to 40 CFR 63.11495(a)(2), owners and
operators must use one of the following methods to control total
organic HAP emissions when transferring certain liquids (those
containing any organic HAP listed in table 1 to 40 CFR part 63, subpart
VVVVVV) to tank trucks or railcars: (1) submerged loading or bottom
loading; (2) routing emissions to a fuel gas system or process; (3)
vapor balancing back to the storage tank or another storage tank
connected by a common header; or (4) venting through a closed vent
system to a control device.
Since we are proposing to add EtO to table 1 to 40 CFR part 63,
subpart VVVVVV, owners and operators of new and existing affected
sources with transferring liquids containing EtO to tank trucks or
railcars would be subject to these same management practices. We are
proposing that these management practices reflect GACT for these
transfer operations. We anticipate that all facilities that may become
subject to the CMAS NESHAP if EtO were to be added to table 1 to 40 CFR
part 63, subpart VVVVVV already use at least one of these management
practices when transferring liquids containing EtO to tank trucks or
railcars. Therefore, we do not expect any additional costs from this
proposed GACT standard.
The EPA is soliciting comments and data on the proposed transfer
operation practices.
6. Standards for Flares That Emit EtO
As previously discussed in section IV.A.3 of this preamble, the EPA
is proposing to add specific requirements for EtO to the CMAS NESHAP
for batch process vents, continuous process vents, and storage tanks in
EtO service. Each of these requirements mandates 99.9 percent control,
reduction in concentration to less than 1 ppmw, or the use of a flare.
These requirements are based on EtO-specific requirements in the MON
and HON. If a flare is used to meet the MON and HON standards for
process vents and storage tanks in EtO service, the owner or operator
must comply with several operational and monitoring requirements that
are reflective of requirements for petroleum refinery flares which
address: (1) the presence of a pilot flame; (2) visible emissions; (3)
flare tip velocity; (4) net heating value of flare combustion zone gas;
and (5) net heating value dilution parameter (if the flare actively
receives perimeter assist air). More details about these requirements
are provided in our
[[Page 7959]]
technology review discussion (see section IV.C.6 of this preamble). As
such, we evaluated the option (i.e., Control Option 1) to require
flares used to comply with the proposed GACT standards for process
vents and storage tanks in EtO service to meet the same operational and
monitoring requirements included in the MON and HON.
Control Option 1 requires various monitoring equipment (i.e.,
hydrogen analyzers, calorimeters, and flow monitors) be installed on
the flare vent gas stream header and/or steam- or air-assist header.
Flares are used to control emissions from sources such as process vents
and storage tanks regulated under other rulemakings including, but not
limited to, the HON and the MON. The HON and MON apply to chemical
manufacturing facilities and already require these types of monitoring
equipment. Given the widespread use of this monitoring equipment in
other, similar chemical manufacturing facilities, we consider Control
Option 1, which includes the use of hydrogen analyzers, calorimeters,
and flow monitors, to be ``generally available'' per the language of
CAA section 112(d)(5).
Using information from the CMAS emissions inventory data (see
section II.C.2 of this preamble), we estimated there are only two
flares at two different facilities that would be impacted by Control
Option 1 (one of the facilities is already subject to the CMAS NESHAP
and the other facility would become subject to the CMAS NESHAP if EtO
is added to table 1 to 40 CFR part 63, subpart VVVVVV, as proposed). We
estimated costs for each flare for a given facility, considering
current monitoring systems already installed on each individual flare.
Given that the same type of equipment is used for flares in the CMAS
categories and for the petroleum refinery sector, we estimated costs
for any additional monitoring systems needed based on installed costs
received from petroleum refineries. If those installed costs were
unavailable, we estimated costs based on vendor-purchased equipment.
The baseline emission estimate and the emission reductions achieved by
Control Option 1 were estimated based on the CMAS emissions inventory
data (see section II.C.2 of this preamble) and current vent gas and
steam flow data submitted by industry representatives.\25\ The results
of the impact estimates are summarized in table 6 of this preamble for
Control Option 1. See the document titled Clean Air Act Section
112(d)(5) GACT Standard Analysis for Flares that Emit Ethylene Oxide
and Section 112(d)(6) Technology Review for Flares Associated with
Chemical Manufacturing Process Units at Area Sources Subject to the
CMAS NESHAP, which is available in the docket for this rulemaking, for
details on the assumptions and methodologies used in this analysis.
Based on the costs and emission reductions for Control Option 1, we are
proposing to revise the CMAS NESHAP for flares used to comply with the
proposed GACT standards for process vents and storage tanks in EtO
service to reflect Control Option 1 pursuant to CAA section 112(d)(5).
The cost-effectiveness of this Control Option is within the range of
values that have been accepted in other recent rulemakings regulating
EtO emissions such as the commercial sterilizer rulemaking (see 89 FR
24090, April 5, 2024) \26\ and is within range of historic cost-
effectiveness values that have been accepted for highly toxic HAP (such
as hexavalent chromium).\27\ EtO is similarly toxic due to its potency
as a carcinogen. As such, we find that this Control Option is cost-
effective.
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\25\ To estimate the baseline control efficiency of volatile
organic compounds (VOC) and HAP anticipated by applying Control
Option 1, we reviewed data submitted to the EPA in 2011 by the
American Petroleum Institute (API), the American Chemistry Council
(ACC), and the National Petrochemical and Refiners Association
(NPRA), now known as the American Fuels and Petrochemical
Manufacturers (AFPM). This dataset includes detailed hourly
operational information for 38 steam-assisted flares, characterizing
different operating conditions by waste gas flow rate, steam flow
rate, waste gas composition, and duration of that operating
condition.
\26\ See footnote 19.
\27\ See footnote 20.
Table 6--Nationwide Emissions Reductions and Cost Impacts of Control Option 1 for Requiring the Suite of Operational and Monitoring Requirements for
Flares That Emit EtO at CMAS Facilities \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
EtO cost
Control option Total capital Total annualized VOC emission EtO emission effectiveness ($/
investment ($) costs ($/yr) reductions (tpy) reductions (tpy) ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
1........................................................ 3,770,000 960,000 12.8 1.56 606,700
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Facilities that would either become subject to the CMAS NESHAP if EtO is added to table 1 to 40 CFR part 63, subpart VVVVVV, as proposed, or are
already subject to the CMAS NESHAP and emit EtO.
We are proposing Control Option 1 for flares at new and existing
affected sources that are used to comply with the proposed GACT
standards for process vents and storage tanks in EtO service at item
4.a of table 2 to the CMAS NESHAP, item 4.a of table 3 to the CMAS
NESHAP, item 5.a of table 5 to the CMAS NESHAP, and 40 CFR
63.11497(f)(5), all by reference to the HON (40 CFR 63.108 and 40 CFR
63.124). These proposed requirements specify that owners and operators
that choose to use a flare to comply with the proposed standards for
process vents and storage tanks in EtO service as described in section
IV.A.3 of this preamble must vent emissions through a closed vent
system and meet the applicable requirements for flares as specified in
40 CFR 63.670 and 63.671, including the provisions in tables 12 and 13
to 40 CFR part 63, subpart CC (i.e., the suite of operational and
monitoring requirements for refinery flares). In addition, we are
proposing amendments to 40 CFR 63.11501(c)(2)(iii) and (c)(4)(vii) to
align the recordkeeping requirements with this proposed Control Option.
We also note that we are proposing an LDAR program for equipment
leaks at 40 CFR 63.11495(a)(6) and (7) (see sections IV.A.1 and IV.C.1
of this preamble). Part of this LDAR program requires owners and
operators that vent equipment leak emissions through a closed vent
system to a flare used to control equipment leaks in EtO service, to
comply with the same suite of operational and monitoring requirements
for flares as we are proposing for flares used to comply with the
proposed GACT standards for process vents and storage tanks in EtO
service (see proposed 40 CFR 63.11495(a)(7)). Given that we only
identified two flares in the CMAS emissions inventory data that emit
EtO and we have already estimated impacts for these flares to comply
with Control
[[Page 7960]]
Option 1, we do not expect any additional costs from this proposed GACT
standard.
7. Standards for Fenceline Monitoring EtO
As discussed in section IV.C.7 of this preamble as well, fenceline
monitoring is the practice by which monitors are placed around the
perimeter of a facility to measure the concentration of certain
pollutants. When required in conjunction with root cause analysis and
corrective action, fenceline monitoring can reduce uncertainties
associated with fugitive emissions estimation and characterization.
This section of the preamble is limited to the discussion of fenceline
monitoring for EtO. Section IV.C.7 of this preamble provides details on
why we are not proposing fenceline monitoring for CMPUs using,
producing, storing, or emitting other table 1 HAP.
In the promulgated amendments to the HON, the EPA finalized a new
EPA method (EPA Method 327 of 40 CFR part 63, appendix A) to monitor
the concentration of EtO at facility fenceline locations. EPA Method
327 provides procedures for canister sampling and analysis for
measuring trace levels of targeted VOC (including organic HAP) in air.
EPA Method 327 collects ambient air samples using specially prepared
and pre-cleaned evacuated stainless-steel canisters. For analysis, the
method specifies procedures for concentrating the target VOC (i.e.,
EtO) in a known volume of air drawn from the canister, desorbing the
target VOC from the preconcentrator, and determining the concentration
of the target VOC using a gas chromatograph-mass spectrometer. The EPA
continues to investigate cost-effective monitoring methods and
technologies that could offer improved sensitivity, improved time
resolution, or increased time integration.
As part of the HON, fenceline monitoring in combination with root
cause analysis and corrective action was required for affected sources
using, producing, storing, or emitting EtO. The program requires a
cannister sample to be collected in accordance with EPA Method 327 for
one 24-hour period every five days. This monitoring frequency is
necessary to ensure that all onsite processes are monitored regularly
while maintaining the cost effectiveness of implementing a canister
monitoring network. A sampling frequency of every 5 days also ensures
that the annual average concentration derived from the fenceline data
are indicative of the actual average emissions from the site by
reducing the possibility that sampling occurs only during emission
spikes. Once samples are analyzed, the lowest sample value for EtO is
subtracted from the highest sample value for EtO, generating a
[Delta]c. This approach subtracts the estimated contributions from
background emissions that do not originate from the facility. The owner
or operator would average the [Delta]c for the most recent year of
samples (73 sampling periods) to calculate an annual average [Delta]c
on a rolling basis (i.e., calculate a new annual average [Delta]c every
5 days using data from the most recent 73 sampling periods). The owner
or operator would compare this rolling annual average [Delta]c against
the concentration action level for EtO. The action level for EtO
established as part of the HON is 0.2 micrograms per cubic meter
([micro]g/m\3\) based on three times the representative detection limit
(RDL) for EtO.
If the annual average [Delta]c for a facility exceeds the action
level, then root cause analysis and corrective action must be
performed. Root cause analysis is an assessment conducted through a
process of investigation to determine the primary underlying cause and
other contributing causes of an exceedance of the action level. If the
underlying causes of the action level exceedance are deemed to be from
sources under the control of the owner or operator, the owner or
operator is required to take corrective action to address the
underlying cause of the exceedance and to bring the annual average
[Delta]c back below the action level as expeditiously as possible.
Completion of the root cause analysis and initial corrective action is
required within 45 days of determining that the annual average [Delta]c
exceeded the action level. If the owner or operator requires longer
than 45 days to implement the corrective actions identified by the root
cause analysis, the owner or operator is required to submit a
corrective action plan no later than 60 days after completion of the
root cause analysis.
After completion of the initial corrective action, if the [Delta]c
for the next three sampling periods for samples collected by EPA Method
327 are below the action level, then the corrective action is assumed
to have fixed the problem, and the owner and/or operator has no further
obligation for additional corrective action. However, if the [Delta]c
for the subsequent sampling periods after initial corrective action is
greater than the action level, then the owner or operator must submit a
corrective action plan and schedule for implementing design, operation,
and maintenance changes to eliminate as quickly as possible and prevent
recurrence of the primary cause and other contributing causes to the
exceedance of the action level, to reduce annual average concentrations
below the action level. If the owner or operator cannot determine the
root cause of the exceedance within 30 days of determining that there
was an exceedance of an action level, the proposed revisions require
use of real-time sampling techniques (e.g., mobile gas chromatographs)
to determine the root cause of the exceedance. While the action
level(s) are based on annual average concentrations, once an action
level is exceeded, each sampling period that exceeds the action level
contributes to the [Delta]c remaining above the action level. An
investigation must be conducted to determine the root cause and, if
appropriate, to correct the root cause expeditiously to bring the
annual average [Delta]c below the action level.
Given the similarities between certain sources subject to the HON
and CMAS CMPUs in EtO service, the threat of adverse effect on human
health (as discussed in section II.A.1 of this preamble), and the
observed inconsistency between modeling the fenceline concentrations of
sources subject to the HON and actual fenceline concentration
measurements,\28\ we assessed whether the same fenceline monitoring
program was appropriate. We find fenceline monitoring via EPA Method
327 to be ``generally available'' per the language of CAA section
112(d)(5). Canister measurements for EtO have been possible since 1999
via Method TO-15. While EPA Method 327 was finalized in May 2024 as
part of the revisions to the HON (see 89 FR 42932); many of the
practices, media, and instrumentation necessary for the analysis have
been available since 2019 via an update to Method TO-15, Method TO-15A.
EPA Method 327 codifies the best practices of Method TO-15A and
mandates enhanced QA/QC approaches, such as a regular validation of the
sampling media, site verification for the sampling, defined sample
holding times, and ongoing field and spike blanks to evaluate
performance. In addition, development of logistics and practices to
support EPA Method 327 laboratory analysis will also be occurring
alongside other, similar chemical manufacturing rulemakings. Lastly, as
a practice, placing monitors around a facility to measure fugitive
emissions has been required as part of
[[Page 7961]]
the Petroleum Refineries NESHAP (40 CFR part 63, subpart CC) since
2018. Given the monitoring technology has been available for several
decades and the methodology, while new, is an adjustment to a well
understood 2019 method to ensure the validity of samples, we find EPA
Method 327 to be ``generally available'' per the language of CAA
section 112(d)(5). Both root cause analysis and corrective action
already take place at facilities where large emission events occur.
When an event occurs, the source will be determined and will be fixed.
This is a regular part of operation and thus root cause analysis and
corrective action are already available to every facility potentially
impacted by the proposed fenceline monitoring management practice.
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\28\ EPA, 2023. Clean Air Act Section 112(d)(6) Technology
Review for Fenceline Monitoring located in the SOCMI Source Category
that are Associated with Processes Subject to HON and for Fenceline
Monitoring that are Associated with Processes Subject to Group I
Polymers and Resins NESHAP. EPA Docket ID No. EPA-HQ-OAR-2022-0730-
0091.
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For the 33 facilities within the proposed source category, Chemical
Manufacturing with Ethylene Oxide, EtO is ubiquitous and should be
present in most streams associated with CMPUs in EtO service. As such,
for these facilities, EtO can act as a surrogate pollutant to track and
limit overall fugitive emissions of HAP at the fenceline. Therefore,
using information from the CMAS emissions inventory (see section II.C.2
of this preamble), we modeled what the fenceline concentrations for EtO
would be for the 33 facilities identified to use, produce, store, or
emit EtO based on whole facility emissions when considering those
options proposed in sections IV.A.1 through IV.A.6 and section IV.A.8.
The modeling showed that 32 of the 33 facilities had EtO fenceline
concentrations at or below 0.2 [micro]g/m\3\, three times the RDL for
EtO and the action level finalized as part of the HON. In addition, the
one facility that was modeled to have a fenceline concentration greater
than 0.2 [micro]g/m\3\ was identified as having a high degree of
uncertainty associated with their emissions inventory as the facility
only reported a single EtO record. In addition to revisions made to the
baseline data, post-control emission reductions were established using
state permitting and approximate impacts (for additional details on
facility specific adjustments to emissions, see appendix 1 of the
document entitled Risk Assessment for the Chemical Manufacturing Area
Source (CMAS) Category in Support of the 2025 Technology Review for the
Proposed Rule, available in the docket for this rulemaking). While
exact emission reductions cannot be calculated due to the nature of
fugitive emissions and uniqueness of each root cause analysis and
corrective action performed as part of the fenceline monitoring
program, we anticipate there will be EtO emission reductions associated
with fenceline monitoring.
The cost of the fenceline monitoring program is shown in table 7 of
this preamble. We estimated the cost required for each impacted
facility to build the necessary housing for the cannisters, purchase
and install the cannisters, and continually monitor the fenceline
concentration of EtO. See the document titled Clean Air Act Section
112(d)(5) GACT Standard Analysis and CAA Section 112(d)(6) Technology
Review for Fenceline Monitoring for Chemical Manufacturing Process
Units Associated with the Chemical Manufacturing Area Sources NESHAP,
which is available in the docket for this rulemaking, for additional
details on the analysis and methodology associated with these costs.
Based on the costs and need to monitor for fugitive emissions of
EtO, we are proposing to revise the CMAS NESHAP to require fenceline
monitoring for EtO if a new or existing affected source uses, produces,
stores, or emits EtO pursuant to CAA section 112(d)(5).
We are soliciting comment on the proposed fenceline monitoring
program and the supporting analysis including the costs, benefits, and
underlying assumptions.
Table 7--Nationwide Cost Impacts for Requiring Fenceline Monitoring for
CMAS That Use, Produce, Store, or Emit EtO at CMAS Facilities \1\
------------------------------------------------------------------------
Total
Number of CMAS facilities impacted Total capital annualized
investment ($) costs ($/yr)
------------------------------------------------------------------------
33.................................... 488,000 20,990,000
------------------------------------------------------------------------
\1\ Facilities that would either become subject to the CMAS NESHAP if
EtO is added to table 1 to 40 CFR part 63, subpart VVVVVV, as
proposed, or are already subject to the CMAS NESHAP and emits EtO.
We are proposing to require fenceline monitoring for CMAS using,
producing, storing, or emitting EtO at 40 CFR 63.11495(a)(8) by
reference to the HON (40 CFR 63.184).
A primary requirement for a fenceline monitoring system is that it
provides adequate spatial coverage for determination of representative
pollutant concentrations at the boundary of the facility. In an ideal
scenario, owners or operators would place fenceline monitors so that
any fugitive plume originating within the facility would have a high
probability of intersecting one or more monitors, regardless of wind
direction. Therefore, by referencing 40 CFR 63.184(b)(3) via 40 CFR
63.11495(a)(8) we propose that each facility would place eight
canisters evenly spaced on the monitoring perimeter. The monitoring
perimeter may be the facility fenceline or may be inside the facility
fenceline, provided all sources of EtO are contained within the
perimeter. The EPA is also proposing to require that facilities move
the canister sampling locations with alternating sampling periods to
ensure complete spatial coverage of the facility. For facilities with
perimeters less than or equal to 5,000 meters, all eight sampling
points would be monitored during each sampling period. For facilities
with perimeters greater than 5,000 meters but less than or equal to
10,000 meters, 16 sampling points would be required; for facilities
with perimeters greater than 10,000 meters, 24 sampling points would be
required. For facilities with EtO emission sources that are not
contained within one contiguous area, the EPA is proposing monitoring
of these secondary areas as well, with the size of the secondary area
dictating the number of canisters.
In addition, we are proposing to allow the subtraction of offsite
interfering sources (as they are not within the control of the owner or
operator) through site-specific monitoring plans, but we are not
providing this option for onsite, non-source category emissions. We
based the action level on facility-wide emissions; therefore, we
considered these non-source category sources in its development.
Applying the fenceline standard to the whole facility will also limit
emissions of EtO from all sources and provide more certainty in
decisions being made as to whether the entire facility emissions align
with what is expected from the EPA's analysis. It will also provide
assurance to fenceline communities that emission reductions are
achieved and maintained.
The EPA is also proposing, by reference to the HON at 40 CFR
63.182(e), that owners or operators report fenceline data on a
quarterly basis. Each report would contain the results for each sample
where the field portion of sampling is completed by the end of the
quarter, as well as for associated field and method blanks (i.e., each
report would contain data for 18 canister sampling periods). Owners or
operators would report these data electronically to the EPA within 45
days after the end of each quarterly period. See section IV.D.1 of this
preamble for further discussion on electronic reporting and section
IV.E.1 of this preamble for further discussion on the compliance dates
being proposed.
[[Page 7962]]
8. PRDs in EtO Service
The CMAS NESHAP regulates PRDs through equipment leak management
practices. These practices require owners and operators to conduct
quarterly sensory-based inspections (using sight, sound, or smell) to
ensure that equipment (including PRDs) is ``sound and free of leaks.''
However, these provisions do not apply to an emissions release from a
PRD (see section IV.B.2 of this preamble for more detail).
The EPA is proposing an LDAR program (using EPA Method 21) for all
equipment in organic HAP service (see section IV.C.1 of this preamble).
Additionally, management practices for PRD releases are being proposed
(see section IV.B.2 of the preamble). A 2023 study at an area source
chemical manufacturing facility indicated that EtO PRD releases because
of railcar switchover contributed to elevated levels of EtO at the
facility's fenceline.\29\ If those emissions had not been released to
the atmosphere, the emissions would be characterized as process vent
emissions and potentially subject to the proposed provisions in section
IV.A.3 of this preamble. Given that neither the equipment leaks nor the
process vents analyses account for the episodic nature of PRD releases
and the observed need via the 2023 study, it is reasonable to consider
a management practice regulating PRDs in EtO service.
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\29\ The study, Assessment of chemical facility ethylene oxide
emissions using mobile and multipoint monitoring, focused on
measuring the concentration of EtO at a chemical manufacturer's
fenceline. Elevated levels of EtO were measured nearest sources of
ground level fugitive emissions such as wastewater outfall and
during periods of irregular operation via PRD releases. The complete
study can be found and read here: <a href="https://doi.org/10.1016/j.aeaoa.2023.100214">https://doi.org/10.1016/j.aeaoa.2023.100214</a>.
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To assess appropriate GACT standards for EtO releases from PRDs, we
reviewed other rulemakings and identified two rules with requirements
for PRDs ``in ethylene oxide service.'' The EPA recently added
requirements to the MON and HON making any release event from a PRD in
EtO service a deviation \30\ from the work practice standards for PRD
releases (see 85 FR 49084, August 12, 2020, and 89 FR 42932, May 16,
2024, respectively).
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\30\ The current HON rule text does not define or use the term
``deviation'' and instead uses the term ``violation.'' Given that
both the CMAS NESHAP and the MON rule text define and uses the term
``deviation'' to describe emissions events, we believe it is more
appropriate to continue to use the term ``deviation'' (in lieu of
``violation'') in all of the CMAS rule text.
---------------------------------------------------------------------------
Given these EtO specific requirements in the MON and HON for PRDs
in EtO service, the minimal operational differences between PRDs at
MON, SOCMI, and CMAS facilities, and to ensure that EtO is not released
to atmosphere from a PRD, we are also proposing at 40 CFR
63.11495(a)(7), by reference to the HON (40 CFR 63.165(e)(3)(v)(D)),
that any release event from a PRD in EtO service at a new or existing
affected source is a deviation of the standard. We do not expect any
additional costs from this proposed GACT standard.
B. What are our other proposed decisions regarding GACT standards for
CMAS, and what is the rationale for those decisions?
In addition to the GACT standards we are proposing for certain
emission sources that emit EtO as discussed in section IV.A of this
preamble, we are also proposing GACT standards for pressure vessels and
PRDs as described in sections IV.B.1 and IV.B.2 of this preamble,
respectively. In addition, we are proposing in section IV.B.3 of this
preamble to clarify regulatory provisions for vent control bypasses for
closed vent systems containing bypass lines.
1. Pressure Vessels
Pursuant to CAA section 112(d)(5), we are proposing new
requirements for pressure vessels that are associated with processes
subject to the CMAS NESHAP. The EPA is proposing to define pressure
vessel at 40 CFR 63.11502(a), by reference to the HON (40 CFR 63.101),
to mean ``a storage vessel that is used to store liquids or gases and
is designed not to vent to the atmosphere as a result of compression of
the vapor headspace in the pressure vessel during filling of the
pressure vessel to its design capacity.'' To eliminate any ambiguity in
applicability or control requirements, the EPA is also proposing at 40
CFR 63.11502(b) to remove the exemption for ``pressure vessels designed
to operate in excess of 204.9 kilopascals (kPa) and without emissions
to the atmosphere'' from the definition of storage tank. This long-
standing exemption is ambiguous with respect to what ``without
emissions to the atmosphere'' means. For example, most pressure vessels
have relief devices that allow for venting when pressure exceeds
setpoints. In many cases, these vents are routed to control devices;
however, control devices are not completely effective (e.g., achieve
95-percent control), and therefore there are emissions to the
atmosphere from these pressure vessels, even if they are controlled.
There are also instances where other components in pressure systems may
allow for fugitive releases because of leaks from fittings or cooling
systems. These events arguably are ``emissions to the atmosphere'' and
therefore it is likely that even if the CMAS NESHAP maintained this
exemption, owners and operators of pressure vessels would still have
uncertainty regarding whether they were subject to substantive
requirements. Therefore, the proposed revisions remove the ambiguity
associated with the exemption and set new GACT standards intended to
limit emissions to the atmosphere from pressure vessels storing organic
HAP with capacities greater than or equal to 20,000 gallons at new and
existing affected sources. We are proposing the same standards for
pressure vessels of any capacity and vapor pressure storing EtO such
that it can be considered to be a storage tank in EtO service. We are
also clarifying in the definition of CMPU at 40 CFR 63.11494(b) that
the collection of equipment that is part of a CMPU includes pressure
vessels.
We estimate a pressure vessel is located at 15 of the 247 CMAS
facilities given that these 15 facilities reported 1,3-butadiene
emissions from processes subject to the CMAS NESHAP, and this chemical
is stored in pressure vessels. We excluded CMAS facilities that may
have pressure vessels storing EtO given that we are proposing more
stringent standards for connectors in EtO service, gas/vapor and light
liquid valves in EtO service, and light liquid pumps in EtO service
(see section IV.A.1 of this preamble). Using information from a 2012
analysis that identified developments for storage vessels at chemical
manufacturing facilities and petroleum refineries,\31\ we estimate a
total HAP emission reduction of 2.24 tpy for all affected pressure
vessels associated with processes subject to the CMAS NESHAP (assuming
10 percent of all CMAS pressure vessels storing 1,3-butadiene would
have components that leak). The nationwide capital cost for the
proposed pressure vessel LDAR requirements for the CMAS NESHAP is about
$3,800 and the annualized capital cost is $3,330.
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\31\ Randall, 2012. Memorandum from Randall, D., RTI
International to Parsons, N., EPA/OAQPS. Survey of Control
Technology for Storage Vessels and Analysis of Impacts for Storage
Vessel Control Options. January 20, 2012. EPA Docket ID No. EPA-HQ-
OAR-2010-0871.
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Based on the costs and emission reductions, we are proposing LDAR
requirements at 40 CFR 63.11497(f) and items 6 and 7 of table 5 to the
CMAS NESHAP that are based on similar no-detectable emission
requirements required for closed vent systems in most chemical sector
NESHAP, including but not limited to the HON and MON. We
[[Page 7963]]
are proposing that these LDAR requirements for pressure vessels reflect
GACT at new and existing affected sources. We did not identify any
additional options beyond this for controlling emissions from pressure
vessels. The requirements would apply to all new and existing affected
sources and impose a standard that requires no detectable emissions at
all times (i.e., owners and operators would be required to meet a leak
definition of 500 ppmv at each point on the pressure vessel where total
organic HAP could potentially be emitted); require initial and annual
leak monitoring using EPA Method 21 of 40 CFR part 60, appendix A-7;
and require routing organic HAP through a closed vent system to a
control device (i.e., no releases to the atmosphere through a pressure
vessel's PRD). These proposed LDAR requirements would also subject
connectors in EtO service, gas/vapor or light liquid valves in EtO
service, and light liquid pumps in EtO service to more stringent LDAR
requirements under the proposed EtO equipment leak standards.
See the document titled Clean Air Act Section 112(d)(5) GACT
Standard Analysis for Pressure Vessels Associated with Processes
Subject to the CMAS NESHAP, which is available in the docket for this
rulemaking, for details on the assumptions and methodologies used in
this analysis.
2. PRDs
The CMAS NESHAP regulates PRDs through equipment leak management
practices. These practices require owners and operators to conduct
quarterly sensory-based inspections (using sight, sound, or smell) to
ensure that a PRD is ``sound and free of leaks'' (see 40 CFR
63.11495(a)(3)). These inspections typically occur when the PRD is
seated, as PRDs are designed to open only during a pressure release
(i.e., when the system pressure exceeds the PRD's set pressure).
The CMAS NESHAP does not explicitly regulate atmospheric pressure
releases, regardless of whether they are single or multiple releases
over time. Consequently, no CMAS facility is subject to numeric
emission limits for PRDs that vent to the atmosphere. It is impractical
to measure emissions from PRDs that release to the atmosphere, making
numeric emission limits inappropriate. However, the EPA has included
work practice standards that regulate atmospheric pressure releases
from PRDs in other chemical sector NESHAP, such as the EMACT standards
(85 FR 40386, July 6, 2020; see 40 CFR 63.1107(h)(3)), the MON (85 FR
49084, August 20, 2020; see 40 CFR 63.2480(e)(3)), and the HON and
Group I Polymers and Resins Industry (P&R I) NESHAP (89 FR 42932, May
16, 2024; see 40 CFR 63.165(e)(3)). The EPA also added PRD work
practice standards to the petroleum refinery NESHAP for similar reasons
(81 FR 45241, December 1, 2015; see 40 CFR 63.648(j)(3)). These PRD
work practice standards (in all these listed NESHAP) require owners and
operators to: (1) implement at least three prevention measures; \32\
(2) perform root cause analysis and corrective action if a PRD releases
emissions directly to the atmosphere; and (3) monitor PRDs using a
system that can identify and record the time and duration of each
pressure release and notify operators when a pressure release occurs.
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\32\ Examples of prevention measures include the following: Flow
indicators, level indicators, temperature indicators, pressure
indicators, routine inspection and maintenance programs, operator
training, inherently safer designs, safety instrumentation systems,
deluge systems, and staged relief systems where the initial PRD
discharges to a control system.
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We assessed whether the same PRD work practice standards, already
included in the previously mentioned NESHAPs, represent GACT (i.e., in
the form of management practices) for CMAS. These standards would
regulate emissions from CMAS PRDs during a pressure release. The PRD
work practice standards require monitoring systems that can alert an
owner or operator when a PRD release occurs. We find this equipment to
be ``generally available'' according to CAA section 112(d)(5). As
noted, this type of monitoring equipment is already mandated under
other chemical sector regulations, including the HON and the MON. Given
its widespread use in similar chemical manufacturing facilities, we
consider the PRD work practice standards, which include the use of
monitoring systems capable of alerting an owner or operator when a PRD
release occurs, to be ``generally available.''
The cost for CMAS facilities to implement a management practice
identical to the work practice standard in the HON and MON and install
monitors for PRDs that vent to the atmosphere is based on the number of
PRDs at each facility. However, we do not have actual equipment counts
for CMAS facilities. To estimate the number of PRDs at CMAS facilities
nationwide, we used HON-specific PRD data that was submitted in
response to the EPA's 2022 CAA section 114 request (see section II.C.3
of this preamble). We calculated an average of 14 atmospheric PRDs in
organic HAP service per CMAS CMPU. Multiplying this average by the
total CMAS processes nationwide (247, assuming one CMPU per CMAS
facility), we estimated there are 3,458 atmospheric PRDs in organic HAP
service nationwide. We excluded 33 facilities \33\ from this analysis
given that we anticipate that these facilities are likely to only
operate PRDs in EtO service that already have PRD monitoring installed.
We used work practice costs from a 2015 memorandum \34\ on PRD impacts
for petroleum refineries to estimate costs for implementing at least
three prevention measures and performing root cause analysis and
corrective action at CMAS facilities. Similarly, based on the HON-
specific PRD data from the EPA's 2022 CAA section 114 request, we
calculated an average of three atmospheric PRDs in organic HAP service
per CMAS CMPU that have a monitoring system installed capable of
identifying releases and recording the time and duration of each
pressure release. Therefore, multiplying the average of 11 (14
atmospheric PRDs less the three that already have monitoring systems
installed) atmospheric PRDs in organic HAP service per CMAS CMPU that
do not have a monitoring system by the total CMAS processes nationwide
(247, assuming one CMPU per CMAS facility), we estimated that of the
3,458 PRDs in organic HAP service nationwide, 2,717 PRDs in organic HAP
service nationwide vent to the atmosphere without a device or
monitoring system capable of identifying releases and recording the
time and duration of each pressure release. We then used PRD monitor
costs from a 2017 memorandum \35\ on PRD options for off-site waste and
recovery operations to estimate the costs for installing PRD monitors
at CMAS facilities. Based on our cost assumptions, the nationwide
capital cost for complying with the PRD work practice requirements for
the CMAS NESHAP (in the form of management practices) is $15.9 million,
with annualized capital costs of $4.7 million. This translates to
approximately $64,300 in total capital investment and $19,200 in total
annual cost per CMAS
[[Page 7964]]
facility. We are unable to estimate HAP reductions from requiring
owners and operators to comply with these management practices because
PRD pressure releases can occur as single or multiple events over time.
In other words, these releases can result from system overpressure
caused by operator error, malfunctions such as power or equipment
failures, or other unexpected causes that necessitate immediate venting
of gas from process equipment to prevent safety hazards or equipment
damage; all of which are too difficult to predict. Even so, we
anticipate that implementing these additional PRD management practices,
along with the proposed equipment leak LDAR program for PRDs (see
section IV.C.1 of this preamble), will achieve significantly greater
emission reductions than the equipment leak management practices
currently required by the CMAS NESHAP.
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\33\ These facilities are already subject to, or may become
subject to, the CMAS NESHAP if EtO were to be added to table 1 to 40
CFR part 63, subpart VVVVVV.
\34\ EPA, 2015. Coburn, Jeff, RTI International. Pressure Relief
Device Control Option Impacts for Final Refinery Sector Rule. July
30, 2015. EPA Docket ID No. EPA-HQ-OAR-2010-0682.
\35\ EPA, 2017. Carey, Angela, EPA/OAQPS. Pressure Relief Device
Control Options and Impacts for Off-Site Waste and Recovery
Operations (OSWRO). June 26, 2017. EPA Docket ID No. EPA-HQ-OAR-
2012-0360.
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As such, pursuant to CAA section 112(d)(5), we are proposing new
requirements for PRDs that are associated with processes subject to the
CMAS NESHAP. We are proposing PRD management practices for all new and
existing affected sources at 40 CFR 63.11495(a)(6), by reference to the
HON (40 CFR 63.165(e)(1) through (8)), that require owners and
operators to: (1) operate each PRD in organic HAP gas or vapor service
with an instrument reading of less than 500 ppm above background as
measured by the method specified in 40 CFR 63.180(c); (2) conduct
instrument monitoring no later than 5 calendar days after the PRD
returns to organic HAP gas or vapor service following a pressure
release to verify that the PRD is operating with an instrument reading
of less than 500 ppm, or if applicable, install a replacement disk as
soon as practicable after a pressure release, but no later than 5
calendar days after the pressure release; (3) implement at least three
prevention measures; (4) perform root cause analysis and corrective
action if a PRD releases emissions directly to the atmosphere; and (5)
monitor PRDs using a system that can identify and record the time and
duration of each pressure release and notify operators when a pressure
release occurs. The EPA is also proposing to define ``pressure relief
device or valve'' at 40 CFR 63.11502(a), by reference to the HON (40
CFR 63.101), to mean ``a valve, rupture disk, or similar device used
only to release an unplanned, nonroutine discharge of gas from process
equipment in order to avoid safety hazards or equipment damage. A PRD
discharge can result from an operator error, a malfunction such as a
power failure or equipment failure, or other unexpected cause. Such
devices include conventional, spring-actuated relief valves, balanced
bellows relief valves, pilot-operated relief valves, rupture disks, and
breaking, buckling, or shearing pin devices. Devices that are actuated
either by a pressure of less than or equal to 2.5 pounds per square
inch gauge or by a vacuum are not pressure relief devices.'' In
addition, the EPA is proposing to define ``pressure release'' at 40 CFR
63.11502(a), by reference to the HON (40 CFR 63.101), to mean ``the
emission of materials resulting from the system pressure being greater
than the set pressure of the pressure relief device. This release can
be one release or a series of releases over a short time period.''
See the document titled Clean Air Act Section 112(d)(5) GACT
Standard Analysis for Pressure Relief Devices Associated with Processes
Subject to the CMAS NESHAP, which is available in the docket for this
rulemaking, for details on the assumptions and methodologies used in
this analysis. We solicit comments on the proposed management practice
for PRDs and assumptions associated with the analysis.
3. Closed Vent System Containing Bypass Lines
For a closed vent system containing bypass lines that can divert
the stream away from the APCD to the atmosphere, the CMAS NESHAP
requires the owner or operator to either: (1) install, maintain, and
operate a continuous parametric monitoring system for flow on the
bypass line that is capable of detecting whether a vent stream flow is
present at least once every hour, or (2) secure the bypass line valve
in the non-diverting position with a car-seal or a lock-and-key type
configuration. Under option 2, the CMAS NESHAP also requires owners or
operators to inspect the seal or closure mechanism at least once per
month to verify the valve is maintained in the non-diverting position
(e.g., for more details see items 1.a and 1.b of tables 2 and 3 to the
CMAS NESHAP and items 1.b and 1.c of table 5 to the CMAS NESHAP, which
all reference provisions in 40 CFR part 63, subpart SS that ultimately
point to bypass monitoring requirements in 40 CFR 63.983(a)(3)). To
expressly prohibit bypassing an APCD at affected sources, as implied by
option 2, we are proposing that an owner or operator may not bypass the
APCD at any time and that a bypass is a violation (see proposed 40 CFR
63.11495(e)), and owners and operators must estimate, maintain records,
and report the quantity of organic HAP released (see proposed 40 CFR
63.11501(c)(10) and (d)(10)). We are proposing these revisions to
ensure continuous compliance with the GACT standards because bypassing
an APCD could result in a release of regulated organic HAP to the
atmosphere that would be required to be controlled under the existing
GACT standards in the CMAS NESHAP. We are also proposing that the use
of a cap, blind flange, plug, or second valve on open-ended valves or
lines (following the requirements specified in 40 CFR 60.482-6(a)(2),
(b), and (c) or following requirements codified in another regulation
that are the same as 40 CFR 60.482-6(a)(2), (b), and (c)) is sufficient
to prevent a bypass. We solicit comments on these proposed revisions.
In addition, we are proposing to remove the 40 CFR 63.107(h)(9)
exemption for ``a gas stream exiting an analyzer'' from the definition
of continuous process vent at 40 CFR 63.11502(b) and we are proposing
at 40 CFR 63.11495(e) to not exempt analyzer vents from the bypass
requirements. As such, we are proposing to require that these kinds of
vents meet the standards applicable to process vents at all times.
Analyzer vents, or ``onstream analyzers,'' generally refer to sampling
systems that directly feed to an analyzer located at a process unit and
venting is expected to be routine (continuous or daily intermittent
venting). We also note that sampling connection systems for CMPUs will
be required to be part of a closed loop, closed purge, or closed vent
system under our proposed equipment leak standards (e.g., 40 CFR
63.166(a), see section IV.C.1 of this preamble for further details). In
these applications, the analyzer vent would not be a bypass of
emissions subject to the requirements in 40 CFR 63.11495 through
63.11498, rather the analyzer vent would be a process vent itself, thus
engineering calculations would be used to determine if this vent is a
process vent requiring control as specified in tables 2 through 4 to
the CMAS NESHAP. In rare instances, the owner or operator may classify
a release point on a gaseous vent system associated with a CMPU as an
``analyzer vent''. In this case, the analyzer vent when open acts as a
bypass line (allowing direct atmospheric release) of a process vent
stream. These examples demonstrate that depending on the circumstance,
an analyzer vent could be construed as a process vent or a bypass line.
Thus, we see no reason to categorically allow use of analyzer vents to
bypass controls required for
[[Page 7965]]
emissions subject to the requirements in 40 CFR 63.11495 through
63.11498.
C. What are the results and proposed decisions based on our technology
review, and what is the rationale for those decisions?
As described in section III.B of this preamble, the technology
review for the CMAS NESHAP focused on the identification and evaluation
of developments in practices, processes, and control technologies that
have occurred since the NESHAP was promulgated in 2009. In conducting
the technology review, we reviewed various sources of information
related to the emissions from chemical manufacturing operations and
other relevant information such as control technologies applied,
management practices used, processes, and monitoring approaches.
Through searches of these data sources, we identified, evaluated, and
considered several developments in practices, processes, or control
technologies. As discussed below, these include developments and
improvements that could result in the addition of emission limits,
management practices, and other emission reduction requirements, as
well as revised compliance assurance measures. We analyzed costs and
emissions reductions for each emission source and determined cost-
effectiveness (annualized cost per ton of emissions reduction) on a HAP
basis. The data, analyses, results, and proposed decisions pursuant to
CAA section 112(d)(6) are presented for each emission source in
sections IV.C.1 through IV.C.7 of this preamble.
Based on this review, the EPA is proposing amendments to the CMAS
NESHAP pursuant to CAA section 112(d)(6) that improve monitoring of
leaks from equipment and heat exchange systems and revises the
definition of ``metal HAP process vent.'' We are not proposing any
changes to the CMAS NESHAP for storage tanks and wastewater based on
our technology review given that we did not identify any cost-effective
developments in practices, processes, or control technologies for these
emission sources that achieve a greater HAP emission reduction beyond
the emission reduction already required by the CMAS NESHAP.
1. Equipment Leaks
Emissions from equipment leaks occur in the form of gases or
liquids that escape to the atmosphere through connection points (e.g.,
threaded connectors) or through the moving parts of different
components (e.g., agitators, compressors, PRDs, pumps, valves) and
certain types of process equipment. Each component type has a unique
manner in which emissions are released (e.g., connectors may leak if
the threads become damaged or corroded or if not tightened
sufficiently, pumps can leak at the point of contact between the moving
shaft and stationary casing, valves can leak through the seal around
the valve stem).
The CMAS NESHAP requires that facilities conduct quarterly
inspections of process vessels and equipment for each CMPU in organic
HAP service or metal HAP service. Equipment is defined as ``each pump,
compressor, agitator, pressure relief device, sampling connection
system, open-ended valve or line, valve, connector, and instrumentation
system in or associated with a CMPU.'' The inspections rely on AVO
detection methods to determine whether process vessels and equipment
are free of leaks. The CMAS NESHAP also allows instrument monitoring
(i.e., use EPA Method 21 with a leak definition of 500 ppmv) in lieu of
AVO methods; or, facilities may use EPA Method 21 to confirm the
presence of HAP for leaks identified using AVO methods.
To identify developments in practices, processes, and control
technologies since the GACT standards were established, we reviewed
subsequent regulatory efforts. After reviewing multiple regulations, we
identified developments in LDAR program practices in the form of
specific leak definitions and monitoring frequencies for LDAR programs
that use EPA Method 21 monitoring that are different than those
evaluated during the original CMAS rulemaking. We used the HON and MON
as initial points of reference to identify developments, since these
rules apply to major source chemical manufacturing facilities which are
similar to CMAS facilities. The HON and MON require EPA Method 21
monitoring for specific components at varying leak definitions (from
500 ppmv to 10,000 ppmv) and frequencies (monthly monitoring to
monitoring every 4 years if few leaks are identified). We also reviewed
the Gasoline Distribution area source rule, which recently undertook a
similar technology review for equipment leaks where the EPA finalized
an LDAR program that requires annual monitoring using EPA Method 21 at
a leak definition of 10,000 ppmv in lieu of only AVO methods. We used
the Gasoline Distribution LDAR program, which requires annual
monitoring at a leak definition of 10,000 ppmv, as the starting option
(i.e., Control Option 1). We then considered two additional options
that would impose more stringent requirements that would allow us to
assess the impacts of more frequent monitoring (i.e., Control Option 2
requiring semiannual monitoring) and a lower leak definition (i.e.,
Control Option 3 requiring a leak definition of 500 ppmv). We also
evaluated the key component types for the LDAR programs (i.e.,
connectors, valves, pumps) and did not consider an option where
connectors were not monitored. The following summarize the three
equipment leak control options that we evaluated for this technology
review: \36\
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\36\ Each equipment leak control option that we evaluated also
includes the HON LDAR requirements specified in 40 CFR 63.164 for
compressors, 40 CFR 63.166 for sampling connection systems, 40 CFR
63.167 for open-ended valves or lines, 40 CFR 63.169 for equipment
in heavy liquid service, 40 CFR 63.173 for agitators in G/V or LL
service.
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<bullet> Control Option 1 (for connectors in gas and vapor (G/V)
service or in light liquid (LL) service, valves in G/V or LL service,
and pumps in LL service): monitor all components annually using EPA
Method 21 and a leak definition of 10,000 ppmv.
<bullet> Control Option 2 (for connectors in G/V or LL service,
valves in G/V or LL service, and pumps in LL service): monitor all
components semiannually using EPA Method 21 and a leak definition of
10,000 ppmv.
<bullet> Control Option 3 (for connectors in G/V or LL service,
valves in G/V or LL service, and pumps in LL service): monitor all
components annually using EPA Method 21 and a leak definition of 500
ppmv.
To estimate the costs and emission reductions, we assumed that 247
CMAS facilities currently follow the CMAS requirement of performing
quarterly AVO inspections and are impacted by this technology review.
For simplicity, we excluded 4 other CMAS facilities from our analysis
that may have equipment leaks in EtO service; and instead, we included
them in our GACT analysis discussed in section IV.A.1 of this preamble.
To get the nationwide impacts of each Control Option, we estimated the
cost and reductions for a model CMAS facility to implement each of the
three control options and multiplied the model facility results by 247.
The memorandum Clean Air Act Section 112(d)(5) GACT Standard Analysis
for Equipment Leaks that Emit Ethylene Oxide and Section 112(d)(6)
Technology Review for Equipment Leaks from Chemical Manufacturing
Process Units at Area Sources Subject to the CMAS NESHAP, which is
available in the docket for this rulemaking, presents
[[Page 7966]]
details on the assumptions and methodologies used in this analysis.
Table 8 of this preamble presents the nationwide impacts for
requiring owners and operators to perform EPA Method 21 monitoring in
accordance with Control Options 1-3. Based on the costs and emission
reductions, we are proposing to revise the CMAS NESHAP for equipment in
HAP service to reflect Control Option 1 pursuant to CAA section
112(d)(6). Control Options 2 and 3 have incremental costs and emission
reductions (i.e., incremental to Control Option 1) that are not cost
effective and we are not proposing to revise the CMAS NESHAP to reflect
either of these options.
Table 8--Nationwide Emissions Reductions and Cost Impacts of Control Options 1-3 for Requiring EPA Method 21 Monitoring for Equipment Leaks at CMAS Facilities
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HAP
incremental
Total Total HAP cost HAP cost cost
Total capital annualized annualized VOC emission HAP emission effectiveness effectiveness effectiveness
Control option investment ($) costs w/o costs with reductions reductions w/o recovery with recovery with recovery
recovery recovery (tpy) (tpy) credits ($/ credits ($/ credits (from
credits ($/yr) credits ($/yr) ton) ton) option 1) ($/
ton)
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1............................................................... 2,499,600 2,220,500 862,000 1,510 151 14,700 5,700
2............................................................... 2,499,600 3,109,700 1,516,600 1,772 177 17,600 8,600 25,000
3............................................................... 2,499,600 3,465,400 1,968,600 1,662 166 20,900 11,800 72,700
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We are proposing Control Option 1 for equipment leaks at 40 CFR
63.11495(a)(6). To effectively incorporate Control Option 1 into the
CMAS NESHAP, we specify at proposed 40 CFR 63.11495(a)(6) that owners
and operators of new and existing affected sources with equipment in
organic HAP service must conduct annual leak detection monitoring of
all pumps in light liquid service, valves in gas/vapor service and in
light liquid service, and connectors in gas/vapor service and in light
liquid service by the method specified in 40 CFR 63.180(b)(1) through
(3), with certain exceptions (e.g., pumps, valves, and connectors that
are unsafe to monitor may be exempt). We also specify at proposed 40
CFR 63.11495(a)(6) that a leak from any of these types of equipment is
detected if the instrument reading equals or exceeds 10,000 ppmv and a
first attempt at repair must be made no later than 5 calendar days
after a leak is detected. Also, we are proposing that equipment must be
repaired as soon as practicable, but no later than 15 calendar days
after the leak is detected, except as allowed in the HON for delay of
repair at 40 CFR 63.171. Additionally, we are proposing at 40 CFR
63.11495(a)(6) the HON LDAR requirements for compressors (i.e., 40 CFR
63.164), sampling connection systems (i.e., 40 CFR 63.166), open-ended
valves or lines (i.e., 40 CFR 63.167), equipment in heavy liquid
service (i.e., 40 CFR 63.169), and agitators in G/V or LL service
(i.e., 40 CFR 63.173). We note that we are also proposing the HON LDAR
requirements for PRDs (i.e., 40 CFR 63.165) which are discussed in
section IV.B.2 of this preamble, and the HON fenceline monitoring
requirements (i.e., 40 CFR 63.184) which are discussed in sections
IV.A.7 and IV.C.7 of this preamble, respectively.
2. Heat Exchange Systems
Heat exchangers are devices or collections of devices used to
transfer heat from process fluids to another process fluid (typically
water) without intentional direct contact of the process fluid with the
cooling fluid (i.e., non-contact heat exchanger). There are two types
of heat exchange systems: closed-loop recirculation systems and once-
through systems. Closed-loop recirculation systems use a cooling tower
to cool the heated water leaving the heat exchanger and then return the
newly cooled water to the heat exchanger for reuse. Once-through
systems typically use surface freshwater (e.g., from a nearby river) as
the influent cooling fluid to the heat exchangers, and the heated water
leaving the system is then discharged from the facility. At times, the
internal tubing material of a heat exchanger can corrode or crack,
allowing some process fluids to mix or become entrained with the
cooling water. Pollutants in the process fluids may subsequently be
released from the cooling water into the atmosphere when the water is
exposed to air (e.g., in a cooling tower for closed-loop systems or
trenches/ponds in a once-through system).
The CMAS NESHAP at 40 CFR 63.11502(a), by reference to the HON (40
CFR 63.101), defines a heat exchange system as ``a device or collection
of devices used to transfer heat from process fluids to water without
intentional direct contact of the process fluid with the water (i.e.,
non-contact heat exchanger) and to transport and/or cool the water in a
closed-loop recirculation system (cooling tower system) or a once-
through system (e.g., river or pond water).'' Pursuant to the recent
technology review for the HON (see 79 FR 25080, May 16, 2024), the
definition also clarifies that: (1) For closed-loop recirculation
systems, the heat exchange system consists of a cooling tower, all CMPU
heat exchangers that are in organic HAP service serviced by that
cooling tower, and all water lines to and from these process unit heat
exchangers; (2) for once-through systems, the heat exchange system
consists of all heat exchangers that are in organic HAP service,
servicing an individual CMPU and all water lines to and from these heat
exchangers; (3) sample coolers or pump seal coolers are not considered
heat exchangers and are not part of the heat exchange system; and (4)
intentional direct contact with process fluids results in the formation
of a wastewater.
The current CMAS NESHAP requirements for heat exchange systems at
40 CFR 63.11499, by re
[…truncated; see source link]Indexed from Federal Register on January 22, 2025.
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