[Federal Register Volume 91, Number 62 (Wednesday, April 1, 2026)]
[Rules and Regulations]
[Pages 16502-16538]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-06304]



[[Page 16501]]

Vol. 91

Wednesday,

No. 62

April 1, 2026

Part V





 Environmental Protection Agency





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40 CFR Part 63





National Emission Standards for Hazardous Air Pollutants: Chemical 
Manufacturing Area Sources Technology Review; Final Rule

Federal Register / Vol. 91, No. 62 / Wednesday, April 1, 2026 / Rules 
and Regulations

[[Page 16502]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2024-0303; FRL-7623-02-OAR]
RIN 2060-AU73


National Emission Standards for Hazardous Air Pollutants: 
Chemical Manufacturing Area Sources Technology Review

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency (EPA) is finalizing 
amendments to the National Emission Standards for Hazardous Air 
Pollutants (NESHAP) for the Chemical Manufacturing Area Source (CMAS) 
categories pursuant to a technology review under Clean Air Act (CAA) 
section 112(d)(6). Specifically, the EPA is finalizing new leak 
detection and repair (LDAR) requirements for equipment leaks and heat 
exchange systems in organic hazardous air pollutant (HAP) service. In 
addition, the EPA is taking final action to add standards for pressure 
relief devices (PRDs) and pressure vessels; require electronic 
reporting for notification of compliance status (NOCS), performance 
test reports, and periodic reports; and require continuous performance 
testing of non-flare air pollution control devices (APCD). The EPA is 
not finalizing the proposed area source category for chemical 
manufacturing with ethylene oxide (EtO) or related standards at this 
time.

DATES: This final rule is effective on April 1, 2026. The Director of 
the Federal Register (FR) has approved incorporation by reference of 
certain publications listed in the rule as of April 1, 2026.

ADDRESSES: The EPA established a docket for this action under Docket ID 
No. EPA-HQ-OAR-2024-0303. All documents in the docket are available at 
https://www.regulations.gov. Although listed, some information is not 
publicly available, e.g., Confidential Business Information or other 
information whose disclosure is restricted by statute. The EPA does not 
place certain other material, such as copyrighted material, on the 
internet; this material is publicly available only as portable document 
format (PDF) versions accessible only on EPA computers in the docket 
office reading room. The public cannot download certain databases and 
physical items from the docket but may request these items by 
contacting the docket office at (202) 566-1744. The docket office has 
10 business days to respond to these requests. With the exception of 
such material, publicly available docket materials are available 
electronically at https://www.regulations.gov or on the EPA computers 
in the docket office reading room at the EPA Docket Center, WJC West 
Building, Room Number 3334, 1301 Constitution Ave. NW, Washington, DC. 
The Public Reading Room hours of operation are 8:30 a.m. to 4:30 p.m. 
Eastern Time (ET), Monday through Friday. The telephone number for the 
Public Reading Room is (202) 566-1744, and the telephone number for the 
EPA Docket Center is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: For information about this final rule, 
contact U.S. EPA, Attn: William Gallagher, Mail Drop: Industrial 
Processing and Power Division (E140C), 109 T.W. Alexander Drive, P.O. 
Box 12055, Research Triangle Park, North Carolina 27711; telephone 
number: (919) 541-2336; and email address: [email protected].

SUPPLEMENTARY INFORMATION: 
    Preamble acronyms and abbreviations. Throughout this notice the use 
of ``we,'' ``us,'' or ``our'' refers 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:

AMEL Alternative Means of Emission Limitation
APCD air pollution control device
CAA Clean Air Act
CDX Central Data Exchange
CEDRI Compliance and Emissions Data Reporting Interface
CFR Code of Federal Regulations
CMAS Chemical Manufacturing Area Source(s)
CMPU chemical manufacturing process unit
EAV equivalent annualized value
EPA Environmental Protection Agency
ERT Electronic Reporting Tool
EtO ethylene oxide
FR Federal Register
GACT generally available control technology
gpm gallons per minute
G/V gas/vapor
HAP hazardous air pollutant(s)
HL heavy liquid
HON Hazardous Organic NESHAP
ICR information collection request
kPa kilopascal(s)
LDAR leak detection and repair
LDSN leak detection and sensor network
LL light liquid
MACT maximum achievable control technology
MON Miscellaneous Organic Chemical Manufacturing NESHAP
NAICS North American Industry Classification System
NESHAP national emission standards for hazardous air pollutants
NOCS notification of compliance status
NRDC Natural Resources Defense Council
NTTAA National Technology Transfer and Advancement Act
OAR Office of Air and Radiation
OGI optical gas imaging
OMB Office of Management and Budget
OSHA Occupation Safety and Health Administration
PDF portable document format
PEPO Polyether Polyols
ppmv parts per million by volume
ppmw parts per million by weight
PRA Paperwork Reduction Act
PRD pressure relief device
PV present value
RFA Regulatory Flexibility Act
RTR risk and technology review
tpy tons per year
UMRA Unfunded Mandates Reform Act
U.S.C. United States Code
VCS voluntary consensus standards
VOC volatile organic compound(s)

Table of Contents

I. General Information
    A. Executive Summary
    B. Does this action apply to me?
    C. What is the statutory authority for this final action?
    D. Where can I get a copy of this document and other related 
information?
    E. Judicial Review and Administrative Reconsideration
    F. Severability
II. Background
    A. What are the CMAS categories, and how does the NESHAP 
regulate HAP emissions from the source categories?
    B. What changes did we propose for the CMAS categories in our 
January 22, 2025, proposal?
    C. What outreach did we conduct following the proposal?
III. What is included in this final rule?
    A. What are the final rule amendments pursuant to CAA section 
112(d)(5) for organic HAP?
    B. What are the final rule amendments based on the technology 
review for the CMAS categories?
    C. What other changes have we made to the NESHAP?
    D. What are the effective and compliance dates of the standards?
IV. What is the rationale for our final decisions and amendments for 
the CMAS categories?
    A. Amendments Pursuant to CAA Section 112(d)(5) for Organic HAP 
for the CMAS Categories
    B. Technology Review for the CMAS Categories
    C. Other Amendments to the CMAS NESHAP
V. Summary of Cost, Environmental, and Economic Impacts and 
Additional Analyses Conducted
    A. What are the affected facilities?
    B. What are the air quality impacts?

[[Page 16503]]

    C. What are the cost impacts?
    D. What are the economic impacts?
    E. What are the benefits?
VI. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Executive Order 14192: Unleashing Prosperity Through 
Deregulation
    C. Paperwork Reduction Act (PRA)
    D. Regulatory Flexibility Act (RFA)
    E. Unfunded Mandates Reform Act (UMRA)
    F. Executive Order 13132: Federalism
    G. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    H. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks
    I. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    J. National Technology Transfer and Advancement Act (NTTAA) and 
1 CFR Part 51
    K. Congressional Review Act (CRA)

    Background information. On January 22, 2025, the EPA proposed 
revisions to the CMAS NESHAP based on the Agency's technology review 
undertaken pursuant to CAA section 112(d)(6).\1\ In that action, the 
EPA also proposed to list and establish standards, pursuant to CAA 
sections 112(c)(3) and (d)(5) respectively, for a new source category 
for area sources that produce a material or family of materials 
described by North American Industry Classification System (NAICS) code 
325 using EtO.\2\
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    \1\ 90 FR 7942 (Jan. 22, 2025).
    \2\ Id.
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    In this final rule, the EPA is establishing standards for existing 
CMAS categories based on the CAA section 112(d)(6) technology review. 
This preamble summarizes some of the more significant comments the EPA 
received regarding the proposed CAA section 112(d)(6) technology review 
and provides the Agency's responses. A summary of all other public 
comments on the proposed CAA section 112(d)(6) technology review and 
the EPA's responses to those comments are in the document Summary of 
Public Comments and Responses for National Emission Standards for 
Hazardous Air Pollutants for Chemical Manufacturing Area Sources, which 
is in the docket for this rulemaking.\3\ A ``track changes'' version of 
the regulatory language that incorporates the changes in this action is 
also in the docket for this rulemaking.
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    \3\ Docket ID No. EPA-HQ-OAR-2024-0303.
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    The EPA is not taking final action at this time on the proposed 
listing and regulation of EtO from area sources producing a material or 
family of materials described by NAICS code 325. The EPA received 
numerous comments and information both in favor of and opposed to the 
proposed listing and regulation of EtO from area sources that produce a 
material or family of materials described by NAICS code 325 (chemical 
manufacturing), and the Agency needs additional time to consider those 
comments before taking final action. The EPA intends to coordinate a 
final action on this issue with the regulation of EtO from major 
sources of HAP. The EPA will address EtO-specific comments on the 
proposed listing and regulation when the Agency takes final action on 
those portions of the proposal.

I. General Information

A. Executive Summary

    In 2009, the EPA promulgated standards to regulate HAP emissions of 
15 air toxics from CMAS pursuant to CAA section 112(c)(3) and (k)(3). 
In 2012, the EPA granted and finalized reconsideration of the CMAS 
NESHAP in response to petitioner concerns on topics such as title V 
permitting, overlap provisions, leak inspections, requirements for 
covers and lids, and the applicability of the NESHAP. As part of the 
2012 rules, the EPA proposed and finalized additional standards for 
periods of startup, shutdown, and malfunction, metal HAP process vents, 
and technical corrections.
    CAA section 112(d)(6) requires the EPA to review and revise 
emission standards ``as necessary'' no less often than every eight 
years (i.e., a technology review). On January 22, 2025, the EPA 
proposed changes to the CMAS NESHAP and solicited public comment.\4\ 
This final action fulfills the EPA's obligation under CAA section 
112(d)(6) and an associated consent decree. The EPA proposed addressing 
EtO emissions from area source chemical manufacturers by proposing to 
list a new area source category and proposing EtO-specific standards 
for several emission process groups. In addition, the EPA proposed more 
general standards and management practices to address fugitive 
emissions from CMAS chemical manufacturing process units (CMPUs), 
including updates to water monitoring methods for heat exchange 
systems, an instrument monitoring program, and new standards for PRDs 
and pressure vessels. Also, the EPA proposed several changes to align 
the CMAS NESHAP with other, similar chemical sector rules. The proposed 
changes included establishing electronic reporting, requiring regular 
performance testing, restricting bypasses, and removing certain 
affirmative defense provisions.
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    \4\ 90 FR 7942 (Jan. 22, 2025).
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    In this final rule, the EPA is finalizing the non-EtO provisions as 
proposed with only clarifying changes and technical corrections. The 
EPA determined that the costs of the final revisions are reasonable and 
not overly burdensome based on the Agency's technical analyses, which 
are available in the docket, and on the Agency's assumption that CMAS 
CMPUs operate similarly to CMPUs subject to major source NESHAP.\5\ 
While commenters expressed some concerns with the proposed standards, 
the EPA did not receive sufficient information to change the analyses. 
The EPA is not taking final action on the proposed EtO area source 
category and emission standards at this time.
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    \5\ Docket ID No. EPA-HQ-OAR-2024-0303.
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    The EPA estimates that this action will have present value (PV) 
costs of $72 million at a three percent discount rate and $56 million 
at a seven percent discount rate over the 2027 to 2041 timeframe (in 
2024 dollars). The EPA estimates that the final action will have an 
equivalent annualized value (EAV) of $6.1 million and $6.2 million per 
year at the same discount rates, respectively (in 2024 dollars).

B. Does this action apply to me?

    Regulated entities. Table 1 of this preamble lists categories and 
entities potentially regulated by this action.

 Table 1--NESHAP and Industrial Source Categories Affected by This Final
                                 Action
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        NESHAP and source categories                  NAICS code
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Agricultural Chemicals and Pesticides        325311, 325312, and 325320.
 Manufacturing.
Cyclic Crude and Intermediate Production...  32511 and 325120.
Industrial Inorganic Chemical Manufacturing  325120, 325130, and 32518.
Industrial Organic Chemical Manufacturing..  325130, 32519, 3256, and
                                              3259.

[[Page 16504]]

 
Inorganic Pigments Manufacturing...........  325130.
Miscellaneous Organic Chemical               325130, 32519, 3256, and
 Manufacturing.                               3259.
Pharmaceutical Production Manufacturing....  325411, 325412, and 325414.
Plastic Materials and Resins...............  325211.
Synthetic Rubber Manufacturing.............  325212.
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    The EPA does not intend table 1 of this preamble to be exhaustive 
but rather to provide a guide for readers regarding entities that this 
final action likely affects for the source categories listed. To 
determine if this action affects your facility, you should examine the 
applicability criteria in the appropriate NESHAP. If you have any 
questions regarding the applicability of any aspect of this NESHAP, 
please contact the appropriate person listed in the preceding FOR 
FURTHER INFORMATION CONTACT section of this preamble.

C. What is the statutory authority for this final action?

    CAA section 112, as amended (42 U.S.C. 7401 et seq.), provides the 
statutory authority for this final action. CAA section 112(d)(6) 
requires the EPA to review technology-based standards and revise them 
``as necessary (taking into account developments in practices, 
processes, and control technologies)'' no less often than every eight 
years following promulgation of those standards. The EPA must conduct 
this ``technology review'' for standards established under CAA section 
112(d), including generally available control technology (GACT) 
standards that apply to area sources.\6\ This action finalizes the CAA 
section 112(d)(6) technology review for the nine area source categories 
affected by the CMAS NESHAP.
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    \6\ For categories of area sources subject to GACT standards, 
CAA sections 112(d)(5) and (f)(5) do not require the EPA to conduct 
a residual risk review pursuant to CAA section 112(f)(2). However, 
the EPA must conduct periodic technology reviews under CAA section 
112(d)(6).
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    Several additional CAA sections are relevant to this action, as 
they specifically address regulation 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.
    CAA section 112(k)(3)(B) 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, 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.'' \7\
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    \7\ 64 FR 38706, 38715 (July 19, 1999).
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    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 nine CMAS 
categories that are addressed in this action.\8\
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    \8\ See id.
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    CAA section 112(d)(5) provides that for area source categories, the 
EPA may promulgate standards or requirements for area sources ``which 
provide for the use of generally available control technology or 
management practices [GACT] by such sources to reduce emissions of 
hazardous air pollutants'' in lieu of setting maximum achievable 
control technology (MACT) standards (which are generally required for 
major source categories). In developing GACT standards, the EPA 
evaluates the control technologies and management practices that reduce 
HAP emissions that are generally available for each area source 
category. Consistent with the legislative history, the EPA can consider 
costs and economic impacts in determining what constitutes GACT.\9\ The 
EPA set GACT standards for the nine CMAS categories in 2009.\10\
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    \9\ Sen. Rep. No. 101-228 (1989).
    \10\ 74 FR 56008 (Oct. 29, 2009).
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D. Where can I get a copy of this document and other related 
information?

    In addition to the docket, an electronic copy of this final action 
is available on the internet at https://www.epa.gov/stationary-sources-air-pollution/chemical-manufacturing-area-sources-national-emission-standards. Following publication in the Federal Register, the EPA will 
post the Federal Register version and key technical documents at this 
same website.

E. Judicial Review and Administrative Reconsideration

    Under CAA section 307(b)(1), judicial review of this final action 
is available only by filing a petition for review in the United States 
Court of Appeals for the District of Columbia Circuit by June 1, 2026. 
Under CAA section 307(b)(2), a party cannot challenge the requirements 
established by this final rule separately in any civil or criminal 
proceedings brought by the EPA to enforce the requirements.
    CAA section 307(d)(7)(B) further provides that only an objection to 
a rule or procedure which a party raised with reasonable specificity 
during the period for public comment (including any public hearing) may 
be raised during judicial review. This section also provides a 
mechanism for the EPA to reconsider the rule if the person raising an 
objection can demonstrate to the Administrator that it was 
impracticable to raise such objection within the period for public 
comment or if the grounds for such objection arose after the period for 
public comment (but within the time specified for judicial review) and 
if such objection is of central relevance to the outcome of the rule. 
Any person seeking to make such a demonstration should submit a 
Petition for Reconsideration to the Office of the Administrator, U.S. 
EPA, Room 3000, WJC South Building, 1200 Pennsylvania Ave. NW, 
Washington, DC 20460, with a copy to both the person(s) listed in the 
preceding FOR FURTHER INFORMATION CONTACT section and the Associate 
General Counsel for the Air and Radiation Law Office, Office of General 
Counsel (Mail Code 2344A), U.S. EPA, 1200 Pennsylvania Ave. NW, 
Washington, DC 20460.

F. Severability

    This final rule contains several discrete components, which the EPA 
views as severable as a practical matter--i.e., they are functionally 
independent and will operate in

[[Page 16505]]

practice without relying on the other components. Sections III.A 
through III.C of this preamble and the technical memoranda available in 
the docket provide detail about these discrete components. In addition, 
as this final rule revises an existing NESHAP, the standards 
promulgated in the 2012 final rule would remain in place in the event 
of an adverse result upon judicial review of this final rule.

II. Background

A. What are the CMAS categories, and how does the NESHAP regulate HAP 
emissions from the source categories?

    The source categories that are the subject of this final action are 
the Agricultural Chemicals and Pesticides Manufacturing, Cyclic Crude 
and Intermediate Production, Industrial Inorganic Chemical 
Manufacturing, Industrial Organic Chemical Manufacturing, Inorganic 
Pigments Manufacturing, Miscellaneous Organic Chemical Manufacturing, 
Pharmaceutical Production, Plastic Materials and Resins Manufacturing, 
and Synthetic Rubber Manufacturing source categories. The EPA 
promulgated the CMAS NESHAP on October 29, 2009, and codified the 
NESHAP at 40 Code of Federal Regulations (CFR) part 63, subpart 
VVVVVV.\11\ As promulgated in 2009 and amended on December 21, 2012, 
the CMAS NESHAP regulates CMPUs at an area source of HAP emissions if 
HAP listed in table 1 to 40 CFR part 63, subpart VVVVVV are used as a 
feedstock, generated as a byproduct, or generated as a product by the 
CMPU.\12\ A CMPU includes all process vessels, equipment, and 
activities necessary to operate a chemical manufacturing process that 
produces a material or a family of materials described by NAICS code 
325, subject to certain exclusions.\13\ 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 that contains one of the table 1 HAP.
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    \11\ 74 FR 56008 (Oct. 29, 2009).
    \12\ 74 FR 56008 (Oct. 29, 2009); 77 FR 75740 (Dec. 21, 2012).
    \13\ Exclusions: (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 nine affected CMAS categories encompass facilities that use as 
feedstocks, 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 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.14 15 In this preamble, we refer to the nine 
source categories collectively as the CMAS categories. Descriptions of 
the nine source categories are as follows:
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    \14\ Feedstocks are reactants, solvents, or any other additives 
to the process.
    \15\ ``Table 1'' refers to table 1 to the CMAS NESHAP.
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    Agricultural Chemicals and Pesticides Manufacturing. NAICS codes 
325311 (nitrogenous fertilizer manufacturing), 325312 (phosphatic 
fertilizer manufacturing), and 325320 (pesticide and other agricultural 
chemical manufacturing) define the agricultural chemicals and 
pesticides manufacturing source category. 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. This section discusses cyclic crude 
and intermediate production, industrial organic chemical manufacturing, 
and miscellaneous organic chemical manufacturing source categories 
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 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 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. 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 325180 
(other basic inorganic chemical manufacturing) define the industrial 
inorganic chemical manufacturing source category. The NESHAP excludes 
certain NAICS code 325180 productions such as 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). Most 
inorganic pigments are oxides, sulfides, oxide hydroxides, silicates, 
sulfates, or carbonates that normally consist of single component 
particles. Inorganic pigment manufacturing processes can generally be 
divided between those that use partial combustion and those that use 
pure pyrolysis. Manufacturers mainly use inorganic pigments 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. Manufacturers of paints and stains, printing 
inks, plastics, synthetic textiles, paper, cosmetics, contact lenses, 
soaps, detergents, wax, modeling clay, chalks, crayons, artists'

[[Page 16506]]

colors, concrete, masonry products, and ceramics use these pigments for 
those products.
    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). NAICS codes 325411 (medicinal and botanical 
manufacturing), 325412 (pharmaceutical preparation manufacturing), and 
325414 (biological product, except diagnostic, manufacturing) define 
the source category.
    Plastic Materials and Resins Manufacturing. NAICS code 325211 
(plastics material and resin manufacturing) designates the plastic 
materials and resins manufacturing source category. 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. NAICS code 325212 (synthetic rubber 
manufacturing) defines the synthetic rubber manufacturing source 
category. 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 September 1, 2025, the EPA identified 251 facilities in 
operation that are subject to the CMAS NESHAP. In this preamble, the 
EPA refers to these facilities collectively as ``CMAS facilities.'' The 
document entitled List of Facilities Subject to the CMAS NESHAP, which 
is in the docket for this rulemaking, presents the list of CMAS 
facilities located in the United States that are part of the CMAS 
categories with processes subject to the CMAS NESHAP.\16\ The EPA notes 
that where the Agency refers to ``area source chemical manufacturers,'' 
we are referring to area sources that manufacture chemicals but are not 
subject to the CMAS NESHAP.
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    \16\ Docket ID No. EPA-HQ-OAR-2024-0303-0028.
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B. What changes did we propose for the CMAS categories in our January 
22, 2025, proposal?

    This section provides a brief summary of the EPA's proposed 
revisions to the CMAS NESHAP.\17\ For additional background 
information, such as how the EPA developed the facility list, refer to 
section II of the proposal preamble.\18\ For descriptions of how the 
EPA determined GACT and how the EPA conducted the technology review, 
refer to section III of the proposal preamble.\19\
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    \17\ On May 24, 2022, the EPA received a complaint alleging that 
the Agency failed to undertake non-discretionary duties related to 
the technology review of the CMAS NESHAP. As a result, on December 
19, 2023, the EPA entered into a consent decree to finalize a 
technology review of the CMAS NESHAP by September 17, 2025, later 
amended by stipulations to March 31, 2026. The EPA issued the 2025 
proposal as part of the Agency's efforts to fulfill the consent 
decree and the Agency's statutory obligations.
    \18\ 90 FR 7942 (Jan. 22, 2025).
    \19\ Id.
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1. Proposed Actions Related to CAA Section 112(d)(5) for Organic HAP
    The EPA proposed first-time requirements under CAA section 
112(d)(5) for pressure vessels, PRDs, and closed vent systems 
containing bypass lines. Specifically, the EPA proposed:
     new monitoring requirements for pressure vessels in 
organic HAP service,
     new management practices for emissions from PRDs in 
organic HAP service, and
     expressly prohibiting bypassing an APCD.
2. Proposed Actions Related to CAA Section 112(d)(6) Technology Review
    Pursuant to the CAA section 112(d)(6) technology review for the 
CMAS NESHAP, the EPA proposed that no revisions to the current 
standards are necessary for wastewater, storage tanks, transfer 
operations, or flares. However, the EPA proposed additional changes 
under CAA section 112(d)(6) for equipment leaks, heat exchange systems, 
and certain process vents.
     For equipment leaks at new and existing affected sources, 
the EPA proposed that owners and operators with equipment in organic 
HAP service must monitor pumps in light liquid (LL) service, valves in 
gas/vapor (G/V) service and LL service, and connectors in G/V service 
and LL service annually via EPA Method 21 with a leak definition of 
10,000 parts per million by volume (ppmv). Additionally, the EPA 
proposed to incorporate the monitoring requirements from 40 CFR part 
63, subpart H for compressors, sampling connection systems, open-ended 
valves or lines, equipment in heavy liquid (HL) service, closed vent 
systems and control devices, and agitators in organic HAP service.
     For heat exchange systems in organic HAP service with flow 
rates greater than or equal to 8,000 gallons per minute (gpm), the EPA 
proposed requirements that owners or operators conduct quarterly 
monitoring (after an initial six months of monthly monitoring if not 
already completed) using the Modified El Paso Method and a leak 
definition of 6.2 ppmv of total strippable hydrocarbon concentration 
(as methane) in the stripping gas.\20\
---------------------------------------------------------------------------

    \20\ The Modified El Paso Method uses a dynamic or flow-through 
system for air stripping a sample of the water and analyzing the 
resultant off-gases for VOC using a common flame ionization detector 
analyzer. Appendix P of the Texas Commission on Environmental 
Quality's Sampling Procedures Manual: The Air Stripping Method 
(Modified El Paso Method) for Determination of Volatile Organic 
Compound (VOC) Emissions from Water Sources describes this method in 
detail. Appendix P is in the docket for this rulemaking (see Docket 
ID No. EPA-HQ-OAR-2024-0303-0030).
---------------------------------------------------------------------------

     For process vents, the EPA proposed to remove the 50 ppmv 
concentration threshold from the definition of ``metal HAP process 
vent.''
Other Proposed Actions
    In addition to the actions described in sections II.B.1 and II.B.2 
of this preamble, the EPA proposed:
     to change the recordkeeping and reporting requirements to 
require the use of the EPA's Central Data Exchange (CDX) using the 
Compliance and Emissions Data Reporting Interface (CEDRI) for 
notifications of compliance status (NOCS), performance test reports, 
and periodic reports;
     to remove affirmative defense provisions from the CMAS 
NESHAP in compliance with Natural Resources Defense Council (NRDC) v. 
EPA, 749 F.3d 1055 (D.C. Cir. 2014);
     to require subsequent performance testing once every five 
years to demonstrate compliance with emission limits for certain 
process vents;
     to remove an exemption for certain wastewater streams 
during periods of startup and shutdown;
     to revise the phrasing used in 40 CFR 63.11502(a) to refer 
to NESHAP

[[Page 16507]]

subpart F in instances where a definition in the CMAS NESHAP points to 
either NESHAP subpart G or H; and
     to make other technical and editorial corrections for the 
CMAS NESHAP.

C. What outreach did we conduct following the proposal?

    As part of this rulemaking, the EPA conducted listening sessions 
with representatives of CMAS facility owners and operators through 
meetings with the American Chemistry Council and Harcros Chemicals Inc. 
in September 2025. Additional details about these meetings are in the 
document Documentation of Meetings with Industry Stakeholders--August 
and September, which is in the docket for this rulemaking.\21\
---------------------------------------------------------------------------

    \21\ Docket ID No. EPA-HQ-OAR-2024-0303-0084.
---------------------------------------------------------------------------

III. What is included in this final rule?

    In this action, the EPA is finalizing the Agency's determinations 
pursuant to the technology review provisions of CAA section 112 for the 
CMAS categories and amending the CMAS NESHAP based on those 
determinations (see sections III.A and III.B of this preamble). The EPA 
also is finalizing other changes to the CMAS NESHAP described in 
section III.C of this preamble. This action also reflects several 
changes from the January 22, 2025, proposal in consideration of 
comments received during the public comment period as described in 
section IV of this preamble. For the EPA's complete responses to the 
submitted comments, please see the document entitled Summary of Public 
Comments and Responses for National Emission Standards for Hazardous 
Air Pollutants for Chemical Manufacturing Area Sources in the docket 
for this rulemaking.
    The EPA is not taking final action on the proposed listing and 
regulation of EtO emissions from chemical manufacturing area sources 
because the Agency needs additional time to consider the comments on 
the proposed listing and regulation of such emissions and because the 
Agency wants to coordinate the regulation of EtO emissions from area 
sources with the regulation of such emissions from major sources. The 
proposed rule distinguished the new listing and regulation of EtO 
emissions from the mandatory technology review of the CMAS rule. The 
EPA listed CMAS categories for specific HAP emissions as part of the 
Urban Air Toxics program under CAA sections 112(c)(3) and 112(k)(3)(B), 
and EtO emissions were not in that listing. For that reason, the EPA's 
responsibility under CAA section 112(d)(6) and the consent decree do 
not apply to the listing and regulation of EtO emissions from chemical 
manufacturing area sources. Thus, the Agency is deferring a final 
decision on the proposed listing and regulation of EtO emissions at 
this time.

A. What are the final rule amendments pursuant to CAA section 112(d)(5) 
for organic HAP?

    For pressure vessels, the EPA is finalizing, as proposed, the 
definition for pressure vessel by reference to the Hazardous Organic 
NESHAP (HON) at 40 CFR 63.101, the removal of 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 
a storage tank, and a no detectable emissions requirement for pressure 
vessels (i.e., each point on the pressure vessel where total organic 
HAP could potentially be emitted must have an instrument reading less 
than 500 ppmv). The no detectable emissions provisions also require 
initial and annual monitoring using EPA Method 21 of 40 CFR part 60, 
Appendix A-7 and routing organic HAP through a closed vent system to a 
control device (i.e., no releases to the atmosphere through any points 
on the pressure vessel).
    For PRDs, the EPA is finalizing, as proposed, the incorporation of 
various practices to minimize emissions from PRD releases and leaks. 
Specifically, the EPA is finalizing PRD management practices that 
require owners and operators to monitor PRDs in organic HAP service for 
leaks after placing a PRD into organic HAP service following a pressure 
release from the PRD. These final provisions also require, as proposed, 
owners and operators to implement preventative measures, perform root 
cause analysis and corrective action if a PRD releases directly to 
atmosphere, and monitor PRDs such that the time and duration of each 
pressure release can be recorded. The EPA is also finalizing the 
Agency's proposed definitions for ``pressure relief device or valve'' 
and ``pressure release'' without changes.
    For closed vent systems with bypass lines, the EPA is finalizing, 
as proposed, that owners and operators may not bypass the APCD at any 
time and that doing so is a deviation from the emission standards. The 
EPA is also finalizing, as proposed, that the use of a cap, blind 
flange, plug, or second valve on open-ended valves or lines is 
sufficient to prevent a bypass. Lastly, the EPA is finalizing, as 
proposed, the removal of the exemption for gas streams exiting 
analyzers.

B. What are the final rule amendments based on the technology review 
for the CMAS categories?

    For equipment leaks in the CMAS categories, the EPA determined that 
there are developments in practices, processes, and control 
technologies that warrant revisions to the GACT standards in the CMAS 
NESHAP pursuant to CAA section 112(d)(6). After considering public 
input, the EPA is finalizing the proposed instrument monitoring program 
(i.e., annual monitoring of pumps in LL service, valves in G/V and LL 
service, and connectors in G/V and LL service) using a leak definition 
of 10,000 ppmv. Additionally, the EPA is finalizing the Agency's 
proposal to incorporate all the requirements from 40 CFR part 63, 
subpart H for compressors, sampling connections systems, open-ended 
valves or lines, equipment in HL service, closed vent systems and 
control devices, and agitators.
    For heat exchange systems in the CMAS categories, the EPA 
determined that there are developments in practices, processes, and 
control technologies that warrant revisions to the GACT standards in 
the CMAS NESHAP pursuant to CAA section 112(d)(6). After considering 
public input, the EPA is finalizing the proposed GACT standards, 
requiring owners and operators to conduct quarterly monitoring for new 
and existing heat exchange systems with flowrates greater than or equal 
to 8,000 gpm (after an initial six months of monthly monitoring if not 
already completed) using the Modified El Paso Method and repair leaks 
of total strippable hydrocarbon concentration (as methane) in the 
stripping gas of 6.2 ppmv or greater without changes. The EPA is also 
finalizing, as proposed, that owners and operators may use the current 
leak monitoring requirements for heat exchange systems at 40 CFR 
63.104(b) in lieu of using the Modified El Paso Method, provided that 
99 percent by weight or more of the organic compounds that could leak 
into the heat exchange system are water soluble and have a Henry's Law 
Constant less than 5.0E-6 atmospheres-cubic meters per mole at 25 
degrees Celsius.
    For process vents in the CMAS categories, the EPA determined that 
there are developments in practices, processes, and control 
technologies that warrant revisions to the GACT standards in the CMAS 
NESHAP pursuant to CAA section 112(d)(6). After

[[Page 16508]]

considering public input, the EPA is revising the definition of ``metal 
HAP process vent'' to remove the 50 ppmv metal HAP concentration 
threshold, as proposed.
    For storage tanks, wastewater streams, and transfer operations in 
the CMAS categories, the EPA is finalizing its proposed determination 
in the technology review that there are no developments in practices, 
processes, and control technologies that warrant revisions to the GACT 
standards. The EPA notes that the Agency is finalizing standards for 
pressure vessels pursuant to CAA section 112(d)(5) (see section III.A 
of this preamble), which eliminates their exemption from the definition 
of ``storage tank'' in the CMAS NESHAP.
    Section III.D of this preamble provides a detailed discussion of 
the effective and compliance dates for the requirements the EPA is 
finalizing in this action for the CMAS NESHAP. Section IV.B.3 of this 
preamble provides a summary of key comments the EPA received on the CAA 
section 112(d)(6) provisions and the Agency's responses.

C. What other changes have we made to the NESHAP?

    This rule also finalizes, as proposed, revisions to several other 
CMAS NESHAP requirements. The EPA describes these revisions in this 
section as well as other proposed provisions that have changed since 
the proposal.
    To increase the ease and efficiency of data submittal and data 
accessibility, the EPA is finalizing, as proposed, a requirement that 
owners or operators submit electronic copies of certain required 
performance test reports, NOCS, and periodic reports through the EPA's 
CDX using the CEDRI. The document Electronic Reporting Requirements for 
New Source Performance Standards (NSPS) and National Emission Standards 
for Hazardous Air Pollutants (NESHAP) Rules, available in the docket 
for this rulemaking, provides a description of the electronic data 
submissions process.\22\ The final rule requires that owners and 
operators submit performance test results in the format generated 
through the use of the EPA's Electronic Reporting Tool (ERT) or an 
electronic file consistent with the XML schema on the ERT website.\23\ 
Electronic files consistent with the XML schema on the ERT website must 
accompany all information required by 40 CFR 63.7(g)(2) in PDF format. 
For periodic reports, the final rule requires that owners or operators 
use the appropriate spreadsheet template to submit information to 
CEDRI. The EPA has made minor clarifying edits to the spreadsheet 
templates based on comments received during the public comment period. 
The final version of the template for these reports will be available 
on the CEDRI website.\24\ The final rule requires that owners or 
operators submit NOCS as a PDF upload in CEDRI. For a more detailed 
discussion of these final amendments, see section IV.D.1 of the 
proposal preamble and sections IV.C and VI.C of this preamble.
---------------------------------------------------------------------------

    \22\ Docket ID No. EPA-HQ-OAR-2024-0303-0006.
    \23\ https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert.
    \24\ https://www.epa.gov/electronic-reporting-air-emissions/cedri.
---------------------------------------------------------------------------

    The EPA also is finalizing, as proposed, initial and recurring 
performance testing to demonstrate compliance with certain process vent 
and storage tank provisions. Additionally, the EPA proposed and is 
finalizing the removal of the design evaluation and engineering 
assessment options for process vents in organic HAP service or metal 
HAP service, respectively. Additionally, consistent with NRDC, the EPA 
is finalizing, as proposed, the elimination of the affirmative defense 
provisions at 40 CFR 63.11501(e) and the definition of ``affirmative 
defense'' in 40 CFR 63.11502(b).
    Lastly, the EPA is finalizing many of the revisions that the Agency 
proposed for clarifying text or correcting typographical errors, 
grammatical errors, and cross-reference errors. These include but are 
not limited to specifying which version of NAICS codes to reference 
when reviewing applicability per 40 CFR 63.11494(c)(2)(iv), removing 
redundant provisions at 40 CFR 63.11496(g)(5), and adding headings at 
40 CFR 63.11497(a) and (c). Section IV.D.3 of the proposal preamble 
discusses the proposed editorial corrections and clarifications. The 
document entitled Summary of Public Comments and Responses for National 
Emission Standards for Hazardous Air Pollutants for Chemical 
Manufacturing Area Sources, which is in the docket for this rulemaking, 
contains the comments on these changes and the EPA's specific responses 
to these items.

D. What are the effective and compliance dates of the standards?

    For the requirements the EPA is finalizing under CAA sections 
112(d)(5) and (6), all existing affected sources and all affected 
sources that were new sources under the previous CMAS NESHAP (i.e., 
sources that commenced construction or reconstruction after October 6, 
2008, and on or before January 22, 2025), must comply with all of the 
amendments no later than April 1, 2029, or upon startup, whichever is 
later, as proposed. For existing sources, CAA section 112(i) provides 
that the compliance date for standards promulgated under CAA section 
112(d) shall be as expeditious as practicable but no later than three 
years after the effective date of the standard.\25\ The EPA agrees with 
the commenters that owners and operators need three years to implement 
the requirements the Agency is finalizing under CAA sections 112(d)(5) 
and (6).\26\ This rulemaking impacts 251 sources, many of which may be 
addressing fugitive emissions from certain sources for the first time 
(e.g., implementing an instrument monitoring program for equipment 
leaks). Facilities need time to purchase and install additional 
equipment or systems, such as preventative measures for PRDs. 
Additionally, the number of CMAS facilities that are near one another 
could potentially strain certain local resources such as LDAR 
contractors or equipment vendors. Owners, operators, and relevant 
authorities may also need to update permits (e.g., New Source Review 
and/or title V operating permit modifications) to account for the 
additional NESHAP requirements. Moreover, we recognize that owners and 
operators may need at least three years to understand the final rule 
changes; revise site guidance and compliance programs; ensure 
operations can meet the standards during startup and shutdown; update 
operation, maintenance, and monitoring plans; and upgrade emissions 
capture and control systems.
---------------------------------------------------------------------------

    \25\ Ass'n of Battery Recyclers v. EPA, 716 F.3d 667, 672 (D.C. 
Cir. 2013) (``Section 112(i)(3)'s three-year maximum compliance 
period applies generally to any emission standard . . . promulgated 
under [section 112].'').
    \26\ See section 6.0 of the document entitled Summary of Public 
Comments and Responses for National Emission Standards for Hazardous 
Air Pollutants for Chemical Manufacturing Area Sources in the docket 
for this rulemaking.
---------------------------------------------------------------------------

    As provided in CAA section 112(i) and 5 U.S.C. 801(a)(3), all new 
affected sources that commenced construction or reconstruction after 
January 22, 2025, must comply with all requirements under CAA sections 
112(d)(5) and (6) by April 1, 2026, or upon startup, whichever is 
later. The EPA provided additional rationale for these compliance dates 
in the preamble to the proposed rule. For the EPA's complete responses 
regarding compliance dates, please see section 6.0 of the document

[[Page 16509]]

entitled Summary of Public Comments and Responses for National Emission 
Standards for Hazardous Air Pollutants for Chemical Manufacturing Area 
Sources in the docket for this rulemaking.
    The EPA is also finalizing provisions that allow up to 150 days 
after the publication date of the final rule for owners or operators of 
affected sources to comply with the requirement to submit NOCS reports 
electronically. The EPA is finalizing, as proposed, provisions that 
allow 60 days after the publication date of the final rule for owners 
or operators of affected sources to comply with the requirement to 
submit the results of performance tests electronically, and three years 
after the publication date of the final rule for owners or operators of 
affected sources to comply with the requirement to submit periodic 
reports electronically.

IV. What is the rationale for our final decisions and amendments for 
the CMAS categories?

    For each issue, this section provides a description of what the EPA 
proposed and what the Agency is finalizing, the EPA's rationale for the 
final decisions and amendments, and a summary of key comments and 
responses. For all comments not discussed in this preamble, the 
document Summary of Public Comments and Responses for National Emission 
Standards for Hazardous Air Pollutants for Chemical Manufacturing Area 
Sources, which is in the docket for this rulemaking, contains the 
comment summaries and the EPA's responses to those comments.

A. Amendments Pursuant to CAA Section 112(d)(5) for Organic HAP for the 
CMAS Categories

    What did we propose pursuant to CAA section 112(d)(5) for organic 
HAP for the CMAS categories?
    Based on the EPA's review of existing standards affecting CMPUs in 
the CMAS categories, the Agency proposed under CAA section 112(d)(5) 
additional standards for pressure vessels, PRDs, and closed vent 
systems containing bypass lines. The EPA provides a summary of the 
Agency's findings, as proposed, in this section.
a. Pressure Vessels
    The EPA proposed to define pressure vessel at 40 CFR 63.11502(a)--
by reference to 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'' 
and to remove the exemption for ``pressure vessels designed to operate 
in excess of 204.9 kilopascals and without emissions to the 
atmosphere'' from the definition of storage tank in 40 CFR 63.11502(b). 
The EPA also proposed to require no detectable emissions at all times 
(i.e., each point on the pressure vessel where total organic HAP could 
potentially be emitted must have an instrument reading less than 500 
ppmv) at 40 CFR 63.11497(f) and item 6 of table 5 to the CMAS NESHAP; 
initial and annual monitoring using EPA Method 21 of 40 CFR part 60, 
Appendix A-7; and routing organic HAP through a closed vent system to a 
control device (i.e., no releases to the atmosphere through any points 
on the pressure vessel).
b. PRDs
    The EPA proposed requirements at 40 CFR 63.11495(a)(6)(iv) 
(incorporating 40 CFR 63.165(e)(1) through (8)) that owners and 
operators must: (1) operate each PRD in organic HAP gas or vapor 
service with less than a 500 ppm difference above background as 
measured by the method specified in 40 CFR 63.180(c); (2) conduct 
instrument monitoring no later than five calendar days after the PRD 
returns to organic HAP gas or vapor service following a pressure 
release or, if applicable, install a replacement rupture disk as soon 
as practicable after a pressure release, but no later than five 
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 also proposed 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 causes. 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 proposed 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.\27\ This release 
can be one release or a series of releases over a short time period.''
---------------------------------------------------------------------------

    \27\ The HON includes multiple part 63 subparts, including 40 
CFR part 63, subparts F, G, and H. 40 CFR 63.101 refers to the 
definitions section of 40 CFR part 63, subpart F.
---------------------------------------------------------------------------

c. Closed Vent Systems Containing Bypass Lines
    The EPA proposed at 40 CFR 63.11495(e) that an owner or operator 
may not bypass an APCD at any time, that a bypass is an emission 
standard deviation, and that owners and operators must estimate, 
maintain records of, and report the quantity of organic HAP released. 
The EPA also proposed 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. 
Lastly, the EPA proposed to remove the exemption for gas streams 
exiting analyzers from the definition of continuous process vent at 40 
CFR 63.11502(b) and to clarify at 40 CFR 63.11495(e) that analyzer 
vents are not exempt from the continuous process vent standards.
2. How did the new standards for organic HAP from the CMAS categories 
change?
    Except for a clarification regarding the pressure vessel 
provisions, the EPA is finalizing the new standards pursuant to CAA 
section 112(d)(5) as proposed. For pressure vessels, based on a comment 
received during the public comment period, the EPA is revising the 
final requirements at 40 CFR 63.11497(e)(2) to clarify that the unsafe 
and difficult/inaccessible monitoring provisions apply to components on 
pressure vessels as well. Notably, the EPA proposed to include unsafe 
and difficult/inaccessible monitoring provisions via reference to 40 
CFR 63.168(h) and (i) (for valves in G/V and in LL service) and 40 CFR 
63.174(f) and (h) (for connectors in G/V and in LL service). However, 
the EPA's revisions instead incorporate the unsafe and difficult/
inaccessible monitoring provisions the Agency proposed and is 
finalizing as part of the final instrument monitoring program for 
equipment leaks

[[Page 16510]]

from valves in G/V or LL service, pumps in LL service, and connectors 
in G/V or LL service (see section IV.B.3.b of this preamble) for 
components on pressure vessels.
3. What key comments did we receive on the proposal revisions pursuant 
to CAA section 112(d)(5) for organic HAP, and what are our responses?
    This section provides summaries of and responses to the key 
comments received regarding (1) the EPA's authority to establish 
requirements for certain emissions sources pursuant to CAA section 
112(d)(5) and (2) the Agency's proposed new monitoring requirements for 
pressure vessels in organic HAP service. The EPA did not receive many 
substantive comments on the other amendments discussed in this section 
IV.A of this preamble. The document entitled Summary of Public Comments 
and Responses for National Emission Standards for Hazardous Air 
Pollutants for Chemical Manufacturing Area Sources, which is in the 
docket for this rulemaking, contains the comments and the EPA's 
specific responses to these issues.
a. CAA Authority
    Comment: Commenters claimed that the EPA failed to appropriately 
recognize the fundamental differences between area and major sources as 
distinct sets of sources with different characteristics, including area 
sources' unique challenges and constraints, such as facility personnel, 
time demands, and available resources. The commenters stated that area 
sources often face these and other pressures in ways that are different 
but no less serious than their major source counterparts. A commenter 
provided an example, saying that the smaller universe of facility 
employees at area sources often means that staff spend more time 
evaluating, understanding, and planning for new regulatory requirements 
and the associated compliance needs. As such, the commenter expressed 
that staff commitments may lead to unplanned disruptions in routine 
operations elsewhere, which can further strain smaller sources that are 
already more resource-constrained than other entities.
    The commenter stated that CAA section 112(d)(5) allows GACT 
requirements to accommodate these challenges and is intentionally more 
streamlined and cost-conscious than other CAA regulatory schemes. 
However, the commenter asserted that the EPA purposefully erased the 
distinction in favor of imposing costly new regulatory burdens on 
smaller entities that would not yield commensurate environmental 
benefit. The commenter stated that the EPA based the proposed standards 
on MACT standards, which, they argued, were never intended to apply to 
area sources. The commenter opined that MACT-level requirements such as 
quarterly instrument monitoring programs would require a dedicated LDAR 
contractor and data management system (resulting in several thousand 
dollars per year of new and potentially unnecessary costs to small 
facilities) while audio, visual, and olfactory programs (GACT level 
requirements) are effectively implemented with minimal facility 
resources.
    Response: The EPA acknowledges that some area sources may face 
distinct challenges from some major sources but disagrees with the 
commenter that the Agency failed to adequately identify and account for 
the differences between major and area sources. The EPA establishes 
MACT standards pursuant to CAA sections 112(d)(2) and (3) using data 
from the best performing sources. The EPA does not consider cost or 
burden when establishing the minimum level of stringency required by 
CAA section 112(d)(3) for initial MACT standards for a source category; 
rather, the EPA does so when determining whether requiring reductions 
beyond the minimum level of stringency is appropriate pursuant to CAA 
section 112(d)(2). Where it is not feasible to prescribe or enforce an 
emission standard, the EPA may promulgate work practice standards 
pursuant to CAA section 112(h).
    In lieu of MACT standards, the EPA may establish GACT standards for 
area sources pursuant to CAA section 112(d)(5). GACT includes 
commercially available methods, practices, and techniques that are 
appropriate for application considering economic impacts and the 
technical capabilities of the affected sources.\28\ As such, consistent 
with the EPA's obligations under CAA section 112(d)(5) and the Agency's 
obligation to complete a technology review pursuant to CAA section 
112(d)(6), the EPA reviewed similar NESHAP, assessed existing 
technologies and practices, and considered other relevant information 
to identify potential control options to consider when proposing and 
finalizing revisions to the CMAS NESHAP. Commenters did not present 
adequate evidence to challenge the EPA's position that many CMAS CMPUs 
subject to GACT standards resemble process units regulated under MACT 
standards in the HON, the Miscellaneous Organic Chemical Manufacturing 
NESHAP (MON), and the Polyether Polyols (PEPO) Production NESHAP. In 
addition, the EPA is aware that many of the affected CMAS CMPUs are 
synthetic area sources that have taken emissions limitations or 
installed federally enforceable control devices to remain below the 
major source emissions threshold of emitting fewer than 10 tpy of a 
single HAP and fewer than 25 tpy of any combination of HAP. If not for 
the emissions limits or control devices, these affected CMAS likely 
would be major sources of HAP and thus subject to major source NESHAP. 
Thus, the EPA maintains that CMAS CMPUs operate similarly to CMPUs 
subject to major source chemical sector rules such as the HON, MON, and 
PEPO NESHAP.
---------------------------------------------------------------------------

    \28\ Sen. Rep. No. 101-228 (1989).
---------------------------------------------------------------------------

    Also, the EPA considered costs for all of the proposed standards 
and found that the costs were comparable or less than those the Agency 
deemed reasonable for organic HAP standards for other chemical sector 
rulemakings such as the MON, Ethylene Production NESHAP, and PEPO 
Production NESHAP. Additionally, the EPA compared the cost of complying 
with the final rule to the annual revenue of an affected entity and 
found that the cost-to-sales ratio was approximately 0.06 percent (see 
the document entitled Economic Impact Analysis for the Final National 
Emission Standards for Hazardous Air Pollutants: Chemical Manufacturing 
Area Sources in the docket for this rulemaking). The EPA notes that 
while the commenters are correct that area sources may have fewer 
resources than major sources, operations at area sources are often 
smaller and less complex (e.g., there are fewer components in organic 
HAP service to monitor) than those at major sources, and so owners and 
operators will need comparatively fewer resources to comply with new 
regulatory requirements.
    Further, where the EPA finds it reasonable to establish or revise 
standards, the level of stringency of a GACT standard may equal the 
level of stringency of a MACT standard. For example, the GACT standards 
in 40 CFR part 63, subpart DDDDDD, which is the polyvinyl chlorides and 
copolymers area source NESHAP, require sources to meet the major source 
MACT requirements of 40 CFR part 63, subpart HHHHHHH for polyvinyl 
chlorides and copolymers for equipment leaks. Further, the EPA notes 
that the GACT standards for process vent emissions for the area source 
PVC manufacturers are more stringent than the process vent emission 
limits for major source PVC

[[Page 16511]]

manufacturers. The proposal preamble as well as the EPA's technical 
analyses (those referenced in sections IV.A through IV.C of the 
proposal preamble, and the document entitled Updated Impact 
Calculations for the CMAS Categories--Final, which is in the docket for 
this rulemaking) outline the basis for the Agency's conclusions that 
the final standards are both reasonable and cost-effective for area 
sources regulated under the CMAS NESHAP.
    Comment: Commenters asserted that the EPA violated the CAA by only 
setting standards for area sources that use, generate, or produce one 
of 15 of the 30 urban HAP to produce a material or family of materials 
described by NAICS code 325. These commenters argued that the EPA must 
finalize standards for all area sources within the listed CMAS 
categories.
    A commenter stated that when the EPA listed the nine CMAS 
categories, the Agency did not limit those listings to sources within 
those categories that use, generate, or produce one of 15 of the 30 
urban HAP, and none of the listing documents limit the CMAS categories 
to any specific HAP. Additionally, the commenter pointed out that the 
EPA explained as part of the 2009 CMAS rulemaking that while the Agency 
limited the final standards to the emissions points that emit one of 
the 15 urban HAP and were sufficient to satisfy the requirements of CAA 
sections 112(c)(3) and (k)(3)(B), the EPA was not ``prohibit[ed] . . . 
from regulating other [hazardous air pollutants] emitted from area 
sources.''
    The commenter continued that the EPA is not prohibited from setting 
standards for all CMAS but is required to set standards that apply to 
all sources in the listed source categories. Referencing CAA section 
112(c)(1), the commenter claimed that it refers to all HAP, not just 
the 30 urban HAP. As such, the commenter argued that the EPA can no 
more set standards for only a subset of area sources than it could for 
major sources. In addition, the commenter noted that the EPA listed 
some area source categories alongside categories that are not limited 
to sources that use, generate, or produce specific urban HAP and 
provided the example of area source hazardous waste combustors.
    To that point, the commenter expressed that the EPA's prior failure 
to regulate all area sources within the listed CMAS categories resulted 
in facilities operating unregulated by NESHAP standards. They said that 
there are many facilities emitting known and unknown HAP that are 
unlawfully evading regulation and that these facilities are 
particularly dangerous when considered in the aggregate and combined 
with major sources. The commenter said that of the 1,300 potentially 
unregulated area sources within the listed CMAS categories that the EPA 
identified as part of the 2009 rulemaking, 127 are in Texas and 
approximately half of those facilities are concentrated in the Greater 
Houston area. They asserted that areas with concentrations of 
unregulated area source chemical manufacturers often overlap with 
cancer risk and other health risk hotspots.
    Also, the commenter added that it is critical that the EPA set 
standards for all area sources within the listed CMAS categories now 
because major sources may attempt to reclassify as area sources (or 
subdivide and reclassify as area sources) to evade HAP regulations.
    Finally, the commenter identified several facilities that the 
existing standards do not cover. The commenter noted that these sources 
emit approximately 75 tons per year (tpy) of methanol, 55 tpy of 
styrene, 35 tpy of ethylene glycol, 20 tpy of hydrogen chloride, 15 tpy 
of formaldehyde, and many tons of other HAP. The commenter stated that 
based on their review of area sources identified by the EPA's 
Integrated Compliance Information System for Air database, when 
compared to CMAS facilities regulated by the CMAS NESHAP, unregulated 
area source chemical manufacturers reported nearly all the emissions of 
certain HAP including ethylene glycol, formaldehyde, xylene, HCl, 
styrene, and methanol.
    The commenter referenced the 2020 National Emissions Inventory and 
said that it included more than 700 facilities within the relevant 
NAICS codes that have emissions less than 10 tpy of one HAP and less 
than 25 tpy of all HAP. They said that of these facilities, more than 
250 do not report emissions of the 15 HAP covered by the existing CMAS 
standards but still report approximately 481 tpy of HAP emissions. The 
commenter also provided several example facilities emitting HAP that do 
not appear to be currently subject to any NESHAP.
    The commenter recommended that the EPA conduct a comprehensive 
analysis to identify all unregulated area source chemical 
manufacturers, assess whether the unregulated area sources present a 
threat of adverse effects to human health or the environment, and set 
strong standards that leave no area sources unregulated.
    Response: The EPA disagrees with the commenter that the Agency has 
not fulfilled our CAA obligations to the CMAS categories pursuant to 
CAA sections 112(c)(1) and 112(k)(3)(B), which set forth the 
requirements for the Urban Air Toxics program. CAA section 112(c)(1) 
states that the Administrator shall ``list categories and subcategories 
of major sources and area sources (listed under [CAA section 
112(c)(3)])'' of the HAP listed pursuant to CAA section 112(b). CAA 
section 112(c)(3) states that the Administrator shall list sufficient 
categories or subcategories of area sources such that ``90 percent of 
the area source emissions of the 30 hazardous air pollutants that 
present the greatest threat to public health'' are subject to 
regulation under CAA section 112.
    As the commenter identifies, the EPA listed the nine CMAS 
categories and set standards for CMPUs emitting at least one of 15 
urban HAP (see table 1 to the CMAS NESHAP) and producing a material or 
family of materials described by NAICS code 325 in the CMAS NESHAP to 
meet these obligations, as well as those of CAA section 112(k)(3)(B). 
While the commenter is correct that the EPA is not prohibited from 
establishing standards for other HAP emitted by CMAS, the CAA does not 
require the EPA to do so. In addition, the EPA notes that the Agency 
did not propose to expand the applicability of the CMAS NESHAP to 
include all CMAS within the nine affected source categories. It would 
not be appropriate for the EPA to finalize an applicability change that 
could potentially subject hundreds or thousands of facilities to the 
CMAS NESHAP for the first time without presenting the regulated 
community an opportunity to comment. The purpose of this action is to 
fulfill the EPA's statutory review obligations to conduct a technology 
review pursuant to CAA section 112(d)(6), and this final rule satisfies 
those mandatory review obligations.
b. Pressure Vessels
    Comment: A commenter opposed the proposed requirement to operate a 
pressure vessel as a closed system that vents through a closed vent 
system to a control device. The commenter stated that pressure vessels 
are designed to not vent during filling and argued that the proposed 
requirements are not necessary, are not cost-effective, would not 
reduce emissions, and do not represent GACT. As an example, the 
commenter said that one facility would need to install a flare at an 
estimated cost of $3,000,000 to control emissions from their pressure 
vessels even though the facility has not reported any emissions or 
releases from the affected pressure vessels in the past five years.

[[Page 16512]]

The commenter continued that the existing Occupation Safety and Health 
Administration (OSHA) Process Safety Management requirements that 
determine the layers of protection needed for accidental releases 
already adequately control such releases.
    Response: The EPA disagrees with the commenter that the requirement 
to operate a pressure vessel as a closed system that vents through a 
closed vent system to a control device does not represent GACT. As the 
commenter states, pressure vessels are designed not to vent during 
filling so releases from a PRD during filling would reflect irregular 
operation, and the EPA maintains that these emissions should be 
controlled given the potential for high volume releases. Additionally, 
prior to this final action, the definition of storage tank in 40 CFR 
63.11502(b) only exempted pressure vessels designed to operate in 
excess of 204.9 kPa and without emissions to the atmosphere. As such, 
the EPA expects that most pressure vessels affected by the addition of 
the standards at 40 CFR 63.11497(e) and table 5 to the CMAS NESHAP 
already should have in place preventative measures as well as capture 
and containment systems capable of preventing emissions from a pressure 
vessel's PRD(s) releasing to atmosphere. In situations where a facility 
must vent a pressure vessel to a control device, the EPA anticipates 
that most facilities will rely on existing APCDs rather than purchasing 
and installing a new APCD, as the EPA expects emissions from pressure 
vessels to be irregular and infrequent, as identified by the 
commenter's example. For additional details on the EPA's expected 
emissions reductions and cost estimates, see the document entitled 
Clean Air Act Section 112(d)(5) GACT Standard Analysis for Pressure 
Vessels Associated with Processes Subject to the CMAS NESHAP, in the 
docket for this rulemaking.\29\ In addition, refer to the document 
entitled Updated Impact Calculations for the CMAS Categories--Final, 
also in the docket for this rulemaking.
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    \29\ Docket ID No. EPA-HQ-OAR-2024-0303-0035.
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    While the requirements of other regulations are outside the scope 
of this action, the EPA emphasizes that OSHA's Process Safety 
Management provisions do not categorically limit the applicability of 
or need for NESHAP requirements.
    Comment: A commenter pointed out that some pressure vessels that 
store regulated chemicals are inside containment areas or partially 
buried such that monitoring the vessel's surface per EPA Method 21 is 
not possible. The commenter added that some of these vessels are 
double-walled tanks designed with an additional external shell outside 
of the pressure vessel shell (i.e., a tank within a shell). As such, 
the commenter recommended that the EPA require monitoring only for 
those points on the pressure vessel that are readily accessible and not 
unsafe-to-monitor.
    Response: The EPA proposed to include provisions for exempting 
equipment that are unsafe or difficult/inaccessible to monitor from the 
proposed pressure vessel requirements by referencing 40 CFR 63.168(h) 
and (i) (for valves in G/V and LL service) and 40 CFR 63.174(f) and (h) 
(for connectors in G/V and LL service). However, because the 
requirements are the same, for clarity the EPA is revising the final 
rule to specify that equipment meeting the criteria specified in 40 CFR 
63.11495(a)(6)(ii)(A) and (C) (for valves in LL or G/V service) and 40 
CFR 63.11495(a)(6)(ii)(A) and (E) (for connectors in LL or G/V service) 
are exempt from the monitoring requirements for pressure vessels.
4. What is the rationale for our final approach and decisions for the 
revisions pursuant to CAA section 112(d)(5) for organic HAP?
    The EPA evaluated all comments on the Agency's proposed amendments 
to include standards for pressure vessels, PRDs, and closed vent 
systems containing bypass lines. The rule did not previously regulate 
these emissions sources, and the EPA considered whether control of 
these sources would be cost effective and feasible for CMAS. Based on 
the analyses discussed in section IV.B of the proposal preamble, the 
document entitled Clean Air Act Section 112(d)(5) GACT Standard 
Analysis for Pressure Vessels Associated with Processes Subject to the 
CMAS NESHAP, the document entitled Clean Air Act Section 112(d)(5) GACT 
Standards Analysis for Pressure Relief Devices Associated with 
Processes Subject to the CMAS NESHAP, and the document entitled Updated 
Impact Calculations for the CMAS Categories--Final, all of which are in 
the docket for this rulemaking, as well as the prevalence of similar 
standards in multiple other chemical sector rulemakings, the EPA finds 
the requirements reasonable and cost-effective for CMAS to 
implement.\30\ \31\ While the EPA received several comments on the 
proposed standards, the commenters did not present any information that 
led us to change our proposed determinations, and the Agency is 
finalizing the standards as proposed. However, the EPA is changing the 
pressure vessel standards to clarify, based on comment, that the unsafe 
and difficult/inaccessible monitoring provisions apply to equipment on 
pressure vessels. Section IV.A.3 of this preamble and in the document 
entitled Summary of Public Comments and Responses for National Emission 
Standards for Hazardous Air Pollutants for Chemical Manufacturing Area 
Sources, which is in the docket for this rulemaking, contain the 
relevant comments and the EPA's specific responses and rationale for 
the Agency's final decisions.
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    \30\ Docket ID No. EPA-HQ-OAR-2024-0303-0032.
    \31\ Docket ID No. EPA-HQ-OAR-2024-0303-0035.
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B. Technology Review for the CMAS Categories

1. What did we propose pursuant to CAA section 112(d)(6) for the CMAS 
categories?
    Based on the EPA's technology review for the CMAS categories, the 
Agency proposed under CAA section 112(d)(6) changes to the CMAS NESHAP 
for heat exchange systems, process vents, and equipment leaks. The EPA 
proposed no change under CAA section 112(d)(6) for storage tanks, 
transfer operations, and wastewater streams. Additionally, with respect 
to fenceline monitoring, the EPA proposed that none of the 15 urban HAP 
regulated on table 1 to the CMAS NESHAP either had established 
fenceline monitoring methods or were sufficiently prevalent across the 
nine CMAS categories to serve as reasonable surrogates for fugitive 
emissions. Also, with respect to flaring for compliance with the 
process vent standards, the EPA proposed that it was not cost effective 
to update CMAS flares with the suite of monitoring and operational 
requirements in 40 CFR 63.670 and 40 CFR 63.671. The EPA provides a 
summary of the Agency's findings, as proposed, in this section of the 
preamble.
a. Heat Exchange Systems
    In the EPA's technology review for the CMAS categories, the Agency 
identified one development in practices and processes for CMAS heat 
exchange systems: the use of the Modified El Paso Method for monitoring 
for leaks from heat exchange systems. The EPA determined that this 
method is more effective at identifying leaks and measures a larger 
number of compounds than the methods previously required in

[[Page 16513]]

the CMAS NESHAP. After evaluating State and Federal regulations 
requiring the Modified El Paso Method, as well as emissions data 
collected for the Refinery Sector risk and technology review (RTR) (see 
section II.D of the proposal preamble and the Refinery Sector RTR 
rulemaking docket), pursuant to CAA section 112(d)(6) the EPA proposed 
to require the use of the Modified El Paso Method at 40 CFR 63.11499(d) 
and item 1.c of table 8 to the CMAS NESHAP--by reference to the HON (40 
CFR 63.104(a) and (f) through (l))--for both new and existing heat 
exchange systems with flow rates greater than or equal to 8,000 
gpm.\32\ The EPA proposed a leak definition of 6.2 ppmv of total 
strippable hydrocarbon concentration (as methane) in the stripping gas 
to further reduce HAP emissions from these heat exchange systems and 
proposed to disallow delay of repair of leaks if the measured 
concentration meets or exceeds 62 ppmv. Based on an evaluation of 
incremental HAP cost effectiveness to increase the leak monitoring 
frequency, the EPA proposed no changes to the monitoring frequency 
previously required by the CMAS NESHAP for heat exchange systems (i.e., 
monthly monitoring for the first six months following startup of a 
source and quarterly monitoring thereafter). The EPA also proposed to 
require re-monitoring at the monitoring location where owners and 
operators identified a leak to ensure that they fixed any leaks found. 
Further, the EPA proposed that none of these proposed requirements for 
heat exchange systems apply to heat exchange systems that have a 
maximum cooling water flow rate of 10 gallons per minute or less. 
Additionally, the EPA proposed that owners and operators may use the 
current leak monitoring requirements for heat exchange systems at 40 
CFR 63.104(b) in lieu of using the Modified El Paso Method, provided 
that 99 percent by weight or more of the organic compounds that could 
leak into the heat exchange system are water soluble and have a Henry's 
Law Constant less than 5.0E-6 atmospheres-cubic meters per mole at 25 
degrees Celsius. Finally, the EPA proposed that owners and operators 
may not inject or dispose of water in a heat exchange system if the 
water is wastewater as defined in 40 CFR 63.11502. Refer to section 
IV.C.2 of the proposal preamble for a summary of the EPA's rationale 
for selecting the proposed leak method, leak definition, and limitation 
on delay of repairs, as well as the Agency's rationale for retaining 
the previous monitoring schedule. For a detailed discussion of the 
EPA's findings, see the document entitled 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.\33\
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    \32\ Docket ID No. EPA-HQ-OAR-2010-0682.
    \33\ Docket ID No. EPA-HQ-OAR-2024-0303-0031.
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b. Process Vents
    As part of the EPA's technology review for the CMAS categories, the 
Agency investigated the basis for the concentration threshold of ``at 
least 50 ppmv metal HAP'' included in the definition of ``metal HAP 
process vent.'' The EPA added this threshold to the definition in 40 
CFR 63.11502(b) as part of the 2012 reconsideration of the NESHAP in 
response to commenters arguing that it was necessary to better 
represent GACT as their sulfuric acid regeneration units already 
achieved over 95 percent reduction in metal HAP.\34\ However, the 
Agency did not at that time conduct any analysis to justify the change. 
As such, the EPA proposed pursuant to CAA section 112(d)(6) to remove 
the 50 ppmv concentration threshold from the definition of ``metal HAP 
process vent'' to ensure that process vents emitting metal HAP were 
subject to control. See section IV.C.3 of the proposal preamble for a 
summary of the EPA's rationale for proposing to remove the 
concentration threshold from the definition of ``metal HAP process 
vent.''
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    \34\ 77 FR 75740 (Dec. 21, 2012).
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c. Equipment Leaks
    In the EPA's technology review for the CMAS categories, the Agency 
identified three control options for further reducing emissions from 
equipment leaks at CMAS facilities. See section IV.C.1 of the proposal 
preamble for a summary of the three options. Based on the EPA's 
evaluation of the feasibility, costs, and emission reductions of each 
option, the Agency proposed pursuant to CAA section 112(d)(6) to revise 
the CMAS NESHAP at 40 CFR 63.11495(a)(6) such 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 
LL service, valves in G/V service and LL service, and connectors in G/V 
service and LL service by following EPA Method 21, with certain 
exceptions (e.g., pumps, valves, and connectors that are unsafe to 
monitor). The EPA also proposed at 40 CFR 63.11495(a)(6) that owners 
and operators must consider a leak from any of these types of equipment 
``detected'' if the instrument reading equals or exceeds 10,000 ppmv 
and that owners and operators must make a first repair attempt no later 
than five calendar days after a leak is detected. Also, the EPA 
proposed that owners and operators must repair equipment as soon as 
practicable but no later than 15 calendar days after the leak is 
detected, except as allowed in 40 CFR part 63, subpart H for delay of 
repair at 40 CFR 63.171. Additionally, the EPA proposed the 
incorporation at 40 CFR 63.11495(a)(6) of the HON LDAR requirements for 
compressors, sampling connection systems, open-ended valves or lines, 
equipment in HL service, closed vent systems and control devices, and 
agitators in G/V or LL service.\35\ For a detailed discussion of the 
EPA's findings, see the document entitled 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.\36\
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    \35\ The HON LDAR requirements for compressors, sampling 
connection systems, open-ended valves or lines, equipment in HL 
service, closed vent systems and control devices, and agitators in 
G/V or LL service appear respectively at 40 CFR 63.164, 40 CFR 
63.166, 40 CFR 63.167, 40 CFR 63.169, 40 CFR 63.172, and 40 CFR 
63.173.
    \36\ Docket ID No. EPA-HQ-OAR-2024-0303-0027.
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2. How did the technology review change for the CMAS categories?
    Apart from a minor reference adjustment to the proposed 
requirements for heat exchange systems in organic HAP service, the EPA 
is finalizing the results of the technology review pursuant to CAA 
section 112(d)(6) for the CMAS categories as proposed without changes. 
The EPA is revising 40 CFR 63.11499(d) and item 1.c of table 8 to the 
CMAS NESHAP to remove the reference to 40 CFR 63.104(k) and instead 
revising 40 CFR 63.11499(d)(6) to provide similar language prohibiting 
owners and operators from injecting or disposing of wastewater via any 
heat exchange system in an affected CMPU.
3. What key comments did we receive on the technology review, and what 
are our responses?
    This section provides summaries of and responses to the key 
comments received regarding the portions of the

[[Page 16514]]

EPA's technology review for the CMAS categories related to heat 
exchange systems, equipment leaks, and flares. The EPA did not receive 
many substantive comments on the other amendments discussed in this 
section IV.C of this preamble. Based on the comments the EPA received 
on the proposed technology review provisions, the Agency is finalizing, 
as proposed, to require monitoring via the Modified El Paso Method for 
heat exchange systems with one minor change. The EPA also is 
finalizing, as proposed, an annual instrument monitoring program for 
equipment leaks and the Agency's decision not to apply the suite of 
operational and monitoring requirements outlined in 40 CFR 63.670 and 
40 CFR 63.671 to flares in organic HAP service at CMAS facilities.
    While the EPA received comments on the Agency's determination that 
there were no cost-effective developments for storage tanks and 
wastewater, commenters did not provide any additional information that 
suggested our analyses were incorrect. Therefore, the EPA is not 
finalizing any changes to the requirements in the CMAS NESHAP for 
storage tanks and wastewater at this time. The document entitled 
Summary of Public Comments and Responses for National Emission 
Standards for Hazardous Air Pollutants for Chemical Manufacturing Area 
Sources, which is in the docket for this rulemaking, contains the 
comment summaries and the EPA's responses to these issues as well as to 
additional issues raised regarding the Agency's technology review's 
proposed requirements for the CMAS categories. Notably, the EPA did not 
receive any comments on the Agency's proposal arguing that there are no 
developments in practices, processes, and control technologies that 
warrant revisions to the GACT standards for transfer operations.
a. Heat Exchange Systems
    Comment: Some commenters objected to the EPA's proposal to replace 
the existing delay of repair options in 40 CFR 63.104(e) (as referenced 
in table 8 to the CMAS NESHAP) with those in 40 CFR 63.104(j), which 
only allow delay of repair for heat exchange systems in organic HAP 
service if the leak is below an action level of 62 ppmv (as methane) in 
the stripping gas. The commenters argued that the proposed option will 
likely lead to facilities with smaller recirculation rates emitting 
more HAP because they may be required to isolate equipment or to shut 
down process equipment as opposed to calculating the emissions from a 
continued leak and delaying repair if they are less than the emissions 
from a shutdown event. In addition, the commenters argued that the 
proposed provisions impose a requirement to fix leaks in scenarios that 
will result in unnecessary emissions and unwarranted safety risks. The 
commenters requested that the EPA not finalize the proposed delay of 
repair requirements and instead keep the existing requirements as they 
provide flexibility for facilities while minimizing environmental 
impact and safety risks.
    Response: The EPA disagrees with the commenters' request to not 
finalize the incorporation of the delay of repair provisions at 40 CFR 
63.104(j) via 40 CFR 63.11499(d) and item 1.c. of table 8 to the CMAS 
NESHAP. First, the commenters appear to have misunderstood the EPA's 
proposal to replace the existing delay of repair options in 40 CFR 
63.104(e) (as referenced in table 8 to the CMAS NESHAP) with those in 
40 CFR 63.104(j). In contrast to the commenters' interpretation, the 
EPA's proposed rule text at 40 CFR 63.104(j), which the Agency is 
finalizing, does allow delay of repair until the next scheduled 
shutdown of the heat exchange system, if the repair is technically 
infeasible without a shutdown and the total strippable hydrocarbon 
concentration or total hydrocarbon mass emissions rate is initially and 
remains less than the delay of repair action level for all monitoring 
periods during the delay of repair.\37\ Second, the final CMAS NESHAP 
only requires monitoring via the Modified El Paso Method for heat 
exchange systems with flow rates greater than or equal to 8,000 gpm, 
and as previously mentioned, the final requirements allow owners and 
operators of these heat exchange systems to delay repair until the next 
scheduled shutdown under certain circumstances. Moreover, heat exchange 
systems with flow rates less than 8,000 gpm are subject to 40 CFR 
63.11495(b), which requires owners and operators to develop and operate 
in accordance with a heat exchange system inspection plan that 
describes the inspections owners and operators must perform at least 
once per quarter.\38\ As such, the EPA expects that the final 
requirements already minimize the burden to facilities with heat 
exchange systems with smaller recirculation rates as they will not be 
subject to monitoring via the Modified El Paso Method nor the 
associated repair requirements.
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    \37\ The delay of repair action level is a total strippable 
hydrocarbon concentration (as methane) in the stripping gas of 62 
ppmv or, for heat exchange systems with a recirculation rate of 
10,000 gallons per minute or less, the delay of repair action level 
is a total hydrocarbon mass emissions rate (as methane) of 1.8 kg/
hr.
    \38\ Inspections as required by 40 CFR 63.11495(b) must provide 
evidence of hydrocarbons in the cooling water and may include checks 
for visible floating hydrocarbon on the water, hydrocarbon odor, 
discolored water, and/or chemical addition rates. Owners and 
operators of these heat exchange systems must also perform repairs 
to eliminate the leak within 45 calendar days after indications of 
the leak are identified but may delay the repair if a reason is 
documented in the next semiannual compliance report.
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    Even considering the minimum flow rate of 8,000 gpm, the EPA 
believes it is important to address sufficiently large leaks (that are 
at least an order of magnitude larger than the leak definition) quickly 
given the potential for large amounts of emissions and a facility's 
general duty to minimize emissions. Notably, the EPA determined that 
large leaks are also significantly more cost-effective to fix than 
small leaks and that the final requirements for heat exchange systems 
in organic HAP service with flow rates greater than or equal to 8,000 
gpm are cost-effective and reasonable when considering a distribution 
of potential leaks, not just those an order of magnitude larger than 
the leak definition. For additional details on the expected emissions 
reductions and costs estimated by the EPA, see the document entitled 
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 in the docket for this rulemaking.\39\ In addition, see the 
document entitled Updated Impact Calculations for the CMAS Categories--
Final, also in the docket for this rulemaking.
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    \39\ Docket ID No. EPA-HQ-OAR-2024-0303-0031.
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    Comment: Commenters requested that the EPA amend the inclusion of 
the language at 40 CFR 63.104 to clarify that the rule will not require 
owners and operators to monitor regulated heat exchange systems using 
water sampling methods or a surrogate indicator pursuant to 40 CFR 
63.104(b) or (c) if the heat exchange system is monitored for leaks 
according to 40 CFR 63.104(g) (i.e., via the Modified El Paso Method). 
The commenters pointed out that the current language does not allow 
sources to stop monitoring using the methods in 40 CFR 63.104(b) or (c) 
once they have begun using the Modified El Paso method. In addition, 
the commenters noted that neither 40 CFR 63.104 nor the referencing 
language in table 8 to the CMAS NESHAP provide a means of ceasing 
compliance with 40 CFR

[[Page 16515]]

63.104(d) once a facility begins complying with 40 CFR 63.104(h) 
through (j).
    Response: The EPA agrees with commenters that the final rule should 
allow sources to stop monitoring using methods in 40 CFR 63.104(b) or 
(c) once they have begun monitoring using the Modified El Paso method. 
However, the EPA disagrees with the commenter that the proposed 40 CFR 
63.11499(d) did not permit sources to discontinue using water sampling 
methods or a surrogate indicator once they begin monitoring via the 
Modified El Paso method. The EPA also disagrees that the proposed 
provisions did not offer a mechanism to end compliance with the repair 
requirements at 40 CFR 63.104(d) after a facility begins complying with 
the repair requirements at 40 CFR 63.104(h) through (j). Under the 
final rule at 40 CFR 63.11499(a), owners and operators must follow the 
requirements outlined in table 8 to the CMAS NESHAP, unless certain 
exceptions apply. According to item 1.c of table 8 to the CMAS NESHAP, 
once the compliance dates have passed, the provisions in items 1.a and 
1.b (i.e., referring to the current monitoring and repair requirements 
in 40 CFR 63.104(b) through (e)) will no longer apply. Instead, owners 
and operators then must comply with the requirements in 40 CFR 
63.104(f) through (j) and (l). Therefore, no revisions to the 
requirements are necessary in response to the commenter's request. The 
EPA is finalizing the proposed rule text without changes, except that 
in the final rule, the EPA is removing the reference to 40 CFR 
63.104(k) and rephrasing 40 CFR 63.11499(d)(7) such that after the 
compliance dates specified in the final 40 CFR 63.11494(i), owners and 
operators may not inject water into or dispose of water in a heat 
exchange system if the water is considered wastewater as defined in 40 
CFR 63.11502(b).
b. Equipment Leaks
    Comment: A commenter generally supported the EPA's proposed CAA 
section 112(d)(6) practices for reducing equipment leaks from equipment 
in organic HAP service (i.e., annual instrument monitoring of 
connectors in G/V and LL service, valves in G/V and LL service, and 
pumps in LL service via EPA Method 21 with a leak definition of 10,000 
ppmv and following the requirements of 40 CFR part 63, subpart H for 
compressors, sampling connection systems, open-ended valves or lines, 
and agitators). However, another commenter contended that the proposed 
instrument monitoring program was inadequate because the EPA failed to 
consider certain developments including fenceline monitoring, low-leak 
and leakless equipment, area monitoring, and ``enhanced LDAR'' 
programs. The commenter argued that although the EPA considered optical 
gas imaging (OGI) and leak detection and sensor networks (LDSNs) as 
developments, the basis for the EPA's rejection was insufficient. The 
commenter suggested that the EPA could require OGI in conjunction with 
the existing leak detection practices and processes directed at lower-
level leaks given the EPA has previously stated that OGI is less 
effective at finding smaller leaks. In response to the EPA's statements 
that OGI cannot observe all chemical compounds, the commenter asserted 
that OGI does not need to observe all chemicals emitted by CMAS to be 
an effective tool in identifying leaks.
    With respect to LDSNs, the commenter suggested that the EPA has 
sufficient information to require the practice given what the commenter 
characterizes as the EPA's collaborative role in developing and testing 
the technology. The commenter said that the EPA could develop LDSNs for 
CMAS and pointed out that the EPA has recently approved the use of an 
LDSN as an Alternative Means of Emission Limitation (AMEL) at the Flint 
Hills Resources West Refinery in Corpus Christi, Texas.
    The commenter also referenced comments on the 2023 HON and 2024 
PEPO Production NESHAP RTR proposals and stated that they contain 
additional information on low-leak and leakless equipment, area 
monitoring, including components of ``enhanced LDAR programs,'' OGI, 
and LDSN.
    Response: The EPA acknowledges the commenters' support for and 
opposition to the proposed instrument monitoring program for equipment 
in organic HAP service. However, the EPA disagrees with the commenter 
that the Agency failed to account for developments in equipment leak 
controls pursuant to CAA section 112(d)(6). The EPA assessed feasible 
options for additional control measures and incorporated those into the 
proposed rule where they demonstrated cost-effective emissions 
reductions and could be reasonably implemented.
    With respect to OGI, as stated in the technical analysis, the EPA 
maintains that CMAS emit a wide variety of chemicals and that OGI 
cannot observe all of them.\40\ While the EPA agrees with the commenter 
that OGI does not necessarily have to observe all chemicals to identify 
a leak, the CMAS NESHAP covers a wide variety of sources using hundreds 
of different chemicals. OGI cameras can detect only compounds that have 
a peak in the spectral range of the filter on the OGI camera (generally 
around 3.2 to 3.4 micron for cameras used to detect hydrocarbons). 
While some of the compounds of interest do have a peak in this range, 
several of the organic compounds listed in table 1 to the CMAS NESHAP 
have very weak peaks or no peaks in the spectral range common to OGI 
camera filters, making it extremely difficult for an OGI camera to see 
these compounds. For example, chloroform's response in this spectral 
range makes it almost impossible to detect with an OGI camera. For 
those compounds that an OGI camera can observe, the detection range of 
the camera varies, and some compounds must be present in high 
quantities before being detectable. As such, the EPA maintains that the 
proposed (and finalized) instrument monitoring program for equipment in 
organic HAP service is most appropriate for detecting equipment leaks 
from CMAS CMPUs at this time.
---------------------------------------------------------------------------

    \40\ Docket ID No. EPA-HQ-OAR-2024-0303-0027.
---------------------------------------------------------------------------

    With respect to LDSNs, as stated in the technical analysis 
document, the EPA does not have the information necessary to develop 
appropriate monitoring requirements that could be incorporated into the 
final rule.\41\ The CMAS NESHAP covers a wide variety of operations 
that involve numerous different HAP, and while the EPA did participate 
in developing and testing LDSNs, the EPA recognizes that consent 
decrees and AMELs are often specific to a facility and not necessarily 
applicable to the wider source category (or source categories in the 
case of the CMAS NESHAP). Additionally, some AMELs, like the one 
mentioned by the commenter, are in use for the first time and need 
further study before the EPA can apply the AMEL's approach more 
broadly.
---------------------------------------------------------------------------

    \41\ Docket ID No. EPA-HQ-OAR-2024-0303-0027.
---------------------------------------------------------------------------

    With respect to the additional information provided by the 
commenter via their comments on the 2023 HON and 2024 PEPO Production 
NESHAP RTR proposals (which the commenter submitted to the docket for 
this action), the EPA notes that the final instrument monitoring 
program for this action is less stringent than the instrument 
monitoring programs in the HON and the PEPO Production NESHAP. It would 
not be necessary to use low-leak and

[[Page 16516]]

leakless equipment to achieve compliance with the final CMAS management 
practices, and low-leak and leakless equipment are typically more 
expensive than standard components. As such, the EPA did not evaluate a 
requirement for low-leak or leakless equipment, as standard equipment 
should be sufficient to meet the proposed, and final, provisions.
    With respect to area monitoring, the CMAS NESHAP regulates a wide 
variety of operations and sources, and the emissions are variable, both 
in expected compounds and magnitude. Based on that variability, the EPA 
does not have sufficient data (e.g., designation of monitored compounds 
for different source categories and different operations, appropriate 
action levels, and spacing of monitors) to establish an area monitoring 
program for the wide variety of operations affected by the CMAS NESHAP.
    Also, as the commenter noted, ``enhanced LDAR programs'' contain 
many of the requirements that the EPA proposed and is finalizing in 
this action. The EPA explained earlier in this response why the Agency 
chose not to include other elements, such as leakless and low-emission 
equipment. Owners and operators may need to add other elements of 
``enhanced LDAR programs'' to improve an existing LDAR program, but 
because the CMAS NESHAP did not previously require instrument 
monitoring for LDAR, the EPA is unable to assess at this time whether 
additional guidance is necessary.
c. Flares
    Comment: Some commenters supported the EPA's decision not to apply 
the suite of operational and monitoring requirements outlined in 40 CFR 
63.670 and 40 CFR 63.671 to flares in organic HAP service at CMAS 
facilities. Commenters noted that although the EPA has incorporated the 
revised flare requirements into several recent rules, the EPA has done 
so selectively based on the flare characteristics of those industries. 
Additionally, the commenter noted that while the EPA has determined 
that the general provisions at 40 CFR 63.11 cannot ensure 98 percent 
control of organic HAP, the GACT process vent and storage tank 
standards applicable to CMAS CMPUs do not require 98 percent control, 
and the costs to apply the revised standards outweigh any incremental 
emissions reductions.
    On the other hand, another commenter argued that the EPA should 
include the suite of flare operational and monitoring requirements in 
the Refinery Sector NESHAP (outlined in 40 CFR 63.670 and 40 CFR 
63.671) in the CMAS NESHAP because some process vent or storage tank 
standards require control efficiencies that are greater than what the 
flare standards in 40 CFR 63.11 can guarantee. The commenter noted that 
the EPA assumed a baseline control efficiency for flares operating 
under the requirements of 40 CFR 63.11 of 85.9 percent and pointed out 
that the only CMAS standards below the assumed baseline control 
efficiency are those for existing batch process vents and periods of 
startup and shutdown for continuous process vents. The commenter 
referenced the EPA's proposal, noting that when the EPA promulgated the 
original CMAS NESHAP in 2009, available data indicated that the 
provisions in 40 CFR 63.11 would enable flares to achieve 98 percent 
control of emissions from process vents and storage tanks. The 
commenter argued that the EPA implied the Agency would not have 
proposed or finalized flaring as a compliance option in the original 
rulemaking if the Agency knew that sources could not reliably achieve 
the assumed 98 percent control level underlying those provisions. The 
commenter urged the EPA to use the same rationale used in the HON and 
Group I Polymer and Resins NESHAP (where the flare requirements were 
updated under CAA section 112(d)(2) and (3)) to update the CMAS 
standards with the suite of flare operational and monitoring 
requirements outlined in 40 CFR 63.670 and 40 CFR 63.671.
    Response: The EPA acknowledges the commenters' support for and 
opposition to the requirement that owners and operators operate CMAS 
flares pursuant to the requirements outlined in 40 CFR 63.670 and 40 
CFR 63.671. The EPA agrees with commenters that none of the process 
vent or storage tank standards for non-flare control devices require a 
reduction of organic HAP emissions by at least 98 percent by weight, 
whether through removal or destruction; those standards only require 85 
to 95 percent control by weight. The EPA also concurs with the 
commenter that flares complying with 40 CFR 63.11 have an assumed 
control efficiency greater than some of the required non-flare APCD 
control efficiencies. However, the EPA disagrees with the commenter's 
assertion that the Agency implied that if we were aware that flares 
complying with 40 CFR 63.11 were not achieving 98 percent control 
efficiency, then we would not have allowed compliance by use of a 
flare. GACT standards consider relevant factors such as cost and burden 
to facilities, whereas MACT standards established under CAA sections 
112(d)(2) and (3) do not. The EPA revised the major source flare 
requirements identified by the commenter pursuant to CAA sections 
112(d)(2) and (3) to ensure compliance with the MACT floor that the EPA 
had established in previous iterations of those rules. However, the 
CMAS NESHAP does not include MACT standards where the EPA identified 
potential underperformance requiring updates to those standards, such 
as changes to the flare requirements in other NESHAP. As such, for the 
EPA's review of the existing flare standards and practices, the Agency 
relied on the technology review authority of CAA section 112(d)(6) and 
considered the development of the suite of operational and monitoring 
requirements outlined in 40 CFR 63.670 and 40 CFR 63.671, consistent 
with our typical approaches. It would be speculative to opine on 
whether the EPA would have established different standards in the 
original rulemaking if the EPA were aware of the costs of ensuring 
flares achieve 98 percent control efficiency. Nonetheless, at this 
time, the EPA considers the costs and burden of operating CMAS flares 
pursuant to the flare requirements in 40 CFR part 63, subpart CC (i.e., 
40 CFR 63.670 and 40 CFR 63.671) unreasonable and not cost-effective 
for CMAS. The EPA notes that the commenters did not provide sufficient 
information for the EPA to consider revising this proposed, and now 
finalized, determination.
    Comment: A commenter argued that CAA section 112(d)(6) does not 
allow the EPA to dismiss developments and refuse to update standards 
based on cost. The commenter asserted that the D.C. Circuit has 
recognized that developments are a core requirement of CAA section 
112(d)(6) and that it is unlawful, arbitrary, and capricious for the 
EPA to propose not to incorporate the flare monitoring and operational 
requirements at 40 CFR 63.670 and 40 CFR 63.671 into the CMAS NESHAP 
because it ignores statutory purposes that the Agency is required to 
consider pursuant to NRDC.
    Response: The EPA disagrees that the Agency has ignored the 
statutory purpose of CAA section 112(d)(6) and that we are prohibited 
from considering costs when determining whether additional controls are 
``necessary'' when conducting a section 112(d)(6) review. The D.C. 
Circuit has repeatedly held to the contrary.\42\ The purpose of

[[Page 16517]]

CAA section 112(d)(6) is to periodically review and update emissions 
standards as necessary. The EPA did not propose any changes to the 
level of control necessary to comply with the process vent and storage 
tank standards, nor did the Agency propose that flares are no longer a 
compliance option for those standards, as established in the original 
rulemaking. Consistent with the requirements of CAA section 112(d)(6), 
the EPA reviewed applying the monitoring and operational requirements 
at 40 CFR 63.670 and 40 CFR 63.671 because those requirements represent 
a development in the control technology. However, reviews conducted 
under CAA section 112(d)(6) are not cost-blind. Considering the costs 
of operating a flare in accordance with 40 CFR 63.670 and 40 CFR 63.671 
and other relevant factors, the EPA determined that it was not 
reasonable or cost-effective to revise the monitoring or operational 
requirements for CMAS flares in this final action. As such, the EPA is 
not finalizing any changes to the final rule in response to this 
comment.
---------------------------------------------------------------------------

    \42\ See, e.g., Ass'n of Battery Recyclers, 716 F.3d at 67; Nat. 
Res. Def. Council v. EPA, 529 F.3d 1077, 1081-82 (D.C. Cir. 2008) 
(holding that EPA's consideration of costs does not invalidate the 
Agency's determination under Section 112(d)(6)).
---------------------------------------------------------------------------

4. What is the rationale for our final approach and decisions for the 
technology review?
    The EPA's technology review focused on the identification and 
evaluation of developments in practices, processes, and control 
technologies that have occurred since the 2012 reconsideration.\43\ 
Specifically, the EPA's technology review focused on the existing GACT 
standards for the various emissions sources in the CMAS categories, 
including heat exchange systems, storage tanks, process vents, transfer 
operations, wastewater, and equipment leaks. In the proposal, the EPA 
identified cost-effective and feasible developments for CMAS heat 
exchange systems, process vents, and equipment leaks, and the Agency 
proposed to revise the standards for these three emissions sources 
under the technology review. The EPA did not identify cost-effective 
and feasible developments in practices, processes, or control 
technologies for transfer operations, storage tanks, and wastewater. 
The proposed rule and the supporting materials in the docket materials 
for this rulemaking contain further information regarding the 
technology review.
---------------------------------------------------------------------------

    \43\ 77 FR 75740 (Dec. 21, 2012).
---------------------------------------------------------------------------

    During the public comment period, the EPA received several comments 
on the Agency's proposed determinations for the technology review. The 
document entitled Summary of Public Comments and Responses for National 
Emission Standards for Hazardous Air Pollutants for Chemical 
Manufacturing Area Sources, which is in the docket for this rulemaking, 
contains the comments and the EPA's specific responses and rationale 
for the Agency's final decisions. Commenters did not present 
information that led us to change our proposed developments for CMAS 
heat exchange systems, process vents, and equipment leaks, and the EPA 
is finalizing revised standards for these three emissions sources, as 
proposed under the technology review. Commenters did not present any 
information that led us to change our proposed determinations under CAA 
section 112(d)(6) for transfer operations, storage tanks, wastewater, 
and flares, and the EPA is finalizing the Agency's determination that 
no changes to these standards are warranted.

C. Other Amendments to the CMAS NESHAP

1. What other amendments did we propose for the CMAS categories?
    The EPA proposed provisions at 40 CFR 63.11496(g)(1)(iv), 40 CFR 
63.11497(g)(1)(iv), and 40 CFR 63.11501(b) and (d) that require owners 
or operators to submit electronic copies of certain required NOCS, 
performance test reports, and periodic reports through the EPA's CDX 
using CEDRI. The EPA also proposed two narrow circumstances in which 
owners or operators may seek extensions to the deadline if conditions 
outside of their control prevent reporting within five business days of 
the reporting deadline. The EPA proposed that an extension may be 
warranted due to outages of the EPA's CDX or CEDRI that precludes an 
owner or operator from accessing the system and submitting required 
reports. The EPA proposed that an extension also may be warranted due 
to a force majeure event, such as an act of nature, act of war or 
terrorism, or equipment failure or safety hazards beyond the control of 
the facility.
    Also, the EPA proposed at 40 CFR 63.11496(f)(2)(i)(E)(ii) that 
owners or operators conduct performance testing once every five years 
to demonstrate compliance with emission limits for certain process 
vents and storage tanks if a source routes emissions to a non-flare 
control device. Specifically, the EPA proposed removing the design 
evaluation option at 40 CFR 63.11496(g)(2) and table 5 of the CMAS 
NESHAP and the engineering assessment option at 40 CFR 
63.11496(f)(3)(ii) and instead requiring ongoing performance tests at 
proposed 40 CFR 63.11496(f)(3)(iv), (4), and (5), and 40 CFR 
63.11496(g)(1)(iii) for owners and operators using a control device 
other than a flare to comply with the emission limits and other 
requirements for batch and continuous process vents and at 40 CFR 
63.11497(g)(1)(iii) for owners and operators using a control device 
other than a flare to comply with the emission limits and other 
requirements for storage tanks.
    In addition, the EPA proposed to eliminate an exemption for certain 
wastewater streams related to periods of startup and shutdown. More 
specifically, the EPA proposed to remove the language at 40 CFR 
63.11498(b) stating that the requirements of item 2 to table 6 of 40 
CFR part 63, subpart VVVVVV for wastewater streams with a partially 
soluble HAP concentrations greater than 10,000 parts per million by 
weight (ppmw) and a separate organic phase do not apply during periods 
of startup or shutdown.
    Additionally, in light of NRDC, which vacated affirmative defense 
provisions in the Portland Cement Manufacturing NESHAP, the EPA 
proposed eliminating the regulatory affirmative defense provisions from 
the CMAS NESHAP at 40 CFR 63.11501(e) in their entirety and the 
definition of ``affirmative defense'' in 40 CFR 63.11502(b).
    Finally, the EPA proposed revisions to clarify text or correct 
typographical errors, grammatical errors, and cross-reference errors. 
These proposed changes include but are not limited to: referring only 
to 40 CFR part 63, subpart F when referring to definitions in the HON; 
identifying the specific version of NAICS codes used to determine rule 
applicability; removing redundant language; and requiring basic 
facility details for reporting purposes. Section IV.D.3 of the proposal 
preamble discusses other proposed editorial corrections and 
clarifications.
2. How did the other amendments for the CMAS categories change since 
proposal?
    Based on comments received on the proposed rulemaking, the EPA is 
making a limited number of minor changes to the amendments described in 
section IV.D.1 of this preamble. With regard to electronic reporting, 
the EPA is making minor clarifying edits to the spreadsheet reporting 
templates; the CEDRI website will contain the final versions of these 
templates. Additionally, the EPA is revising the proposed provisions to 
allow in the final rule owners and operators to

[[Page 16518]]

submit the NOCS up to 150 days after the effective date of the rule. 
Otherwise, the EPA is finalizing the proposed changes to the CMAS 
NESHAP identified in section III.C of this preamble and IV.D of the 
proposal preamble without change.
3. What key comments did we receive on the other amendments for the 
CMAS categories, and what are our responses?
    This section provides summaries of and responses to the key 
comments received regarding the EPA's proposal to eliminate (1) the 
design evaluation option at 40 CFR 63.11496(g)(2) and table 5 to the 
CMAS NESHAP and (2) an exemption at 40 CFR 63.11498(b) for certain 
wastewater streams during periods of startup and shutdown. The EPA did 
not receive many substantive comments on the other amendments discussed 
in this section IV.C of this preamble. The comments the EPA received 
generally supported the Agency's proposal for owners or operators to 
submit electronic copies of specified performance test reports and 
periodic reports via the EPA's CDX using CEDRI, as well as our proposal 
to remove the affirmative defense provisions. The comments the EPA 
received regarding other amendments generally include issues related to 
electronic reporting, ongoing performance testing, and revisions that 
the Agency proposed for addressing technical and editorial corrections. 
The document entitled Summary of Public Comments and Responses for 
National Emission Standards for Hazardous Air Pollutants for Chemical 
Manufacturing Area Sources, available in the docket for this 
rulemaking, contains the comments and the EPA's specific responses to 
these issues.
a. Performance Testing
    Comment: Some commenters opposed the EPA's proposal to remove the 
design evaluation option at 40 CFR 63.11496(g)(2) and table 5 to the 
CMAS NESHAP and instead favored retaining that option rather than 
requiring periodic performance testing to demonstrate compliance with 
the storage tank or process vent control requirements.
    Commenters claimed that area sources face unique challenges to 
conducting stack testing, including low flow, small duct/vent 
diameters, and other measurement obstacles. The commenters also 
remarked that performance testing represents a significant expense for 
smaller area sources compared to major sources. These commenters noted 
that it was unclear why the EPA proposed eliminating the design 
evaluation option for CMAS, given that in other major source 
rulemakings the EPA retained similar provisions, such as those for 
storage vessels with closed vent systems, transfer racks, and 
wastewater control devices under the HON, as well as those for storage 
vessels and small control devices under the MON.
    Another commenter asserted that periodic performance testing is 
overly burdensome to facilities that use non-flare control devices for 
operational or cost reasons and will not result in a commensurate 
benefit to human health or the environment. The commenter provided that 
in many instances sampling at the inlet to a control device can create 
a safety hazard. The commenter requested that, at minimum, the EPA 
incorporate provisions in the final rule that allow for reduced 
performance testing frequency based on a history of good performance. 
Additionally, the commenter asked that the EPA not require repeat 
performance testing unless there has been a change to the process or to 
the control device. Conversely, another commenter expressed support for 
the EPA's proposal to require performance testing of non-flare control 
devices every five years.
    Response: The EPA acknowledges the commenters' support for and 
opposition to the provisions requiring a performance test of non-flare 
control devices initially and once every five years subsequently. 
However, the commenters provided no supporting information for their 
claim that performance testing represents a significant cost to area 
sources. The economic analysis conducted for the proposed action 
identified that the average annual revenue for an affected CMAS entity 
was approximately $12,500 million.\44\ Even for small businesses 
exclusively, the analysis determined that the average annual revenue 
was $230 million. As part of the EPA's information collection request 
(ICR) supporting statement, the Agency estimated that a performance 
test would cost less than $50,000.\45\ As such, the EPA does not 
anticipate that the costs of initial and subsequent performance tests 
will significantly impact an average or small entity, given that the 
estimated costs represent approximately 0.02 percent of the total 
annual costs to a small entity and are incurred only once every five 
years.\46\
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    \44\ Docket ID No. EPA-HQ-OAR-2024-0303-0025.
    \45\ Docket ID No. EPA-HQ-OAR-2024-0303-0039.
    \46\ See the document entitled Economic Impact Analysis for the 
Final National Emission Standards for Hazardous Air Pollutants: 
Chemical Manufacturing Area Sources, available in the docket for 
this rulemaking.
---------------------------------------------------------------------------

    With respect to unique challenges at area sources, the EPA 
acknowledges that control devices at CMAS may be smaller than those at 
major source facilities. While low flow and small duct/vent diameters 
can present some measurement challenges, the EPA expects facilities 
will be able to purchase or install equipment, increase throughput, or 
otherwise address these concerns, as facilities subject to other area 
source NESHAP that require regular performance testing, such as the 
gasoline distribution NESHAP, the polyvinyl chloride and copolymers 
production NESHAP, and the hazardous waste combustors NESHAP, have 
achieved compliance with similar requirements for many years.\47\ 
Additionally, the EPA notes that many CMAS subject to the NESHAP are 
synthetic area sources already subject to title V requirements and as 
such already conduct performance tests to revise and update their 
permits on a five-year basis. The EPA notes that owners and operators 
may apply to use an alternative test method in accordance with the 
provisions of 40 CFR 63.7(f) for site-specific issues that may make the 
specified methods difficult to use, such as interferants, unusual flow 
situations, etc.
---------------------------------------------------------------------------

    \47\ See 40 CFR part 63 subparts BBBBB, DDDDDD, and EEE, 
respectively.
---------------------------------------------------------------------------

    In response to the commenters who pointed out that the EPA has 
retained the design evaluation option in certain major source 
rulemakings, the EPA emphasizes that verifying compliance with the 
standards is especially critical for CMAS. The EPA has found that 
control devices often fall short of the efficiency levels claimed by 
manufacturers for various reasons. However, the CAA limits area sources 
to having a potential to emit less than 10 tpy for any single HAP and 
25 tpy for any combination of HAP. Therefore, reduced control 
efficiency can lead to higher-than-expected emissions, potentially 
causing a facility to exceed the 10/25 tpy thresholds established by 
regulation. This potential impact is particularly relevant for 
synthetic area sources, which take enforceable limits on their control 
device(s) to remain below major source thresholds. The EPA also notes 
that a single compliant performance test does not guarantee future good 
performance. Control efficiency can degrade over time, and it is 
important to reassess the operation of the control device as it ages. 
Additionally, operators and practices

[[Page 16519]]

may change over time, and a performance test every five years ensures 
that APCDs continue to meet the standards.
    Comment: A commenter requested that the EPA extend the deadline for 
submitting a NOCS from the proposed 60 days to 150 days after the final 
rule's effective date. This NOCS, as proposed, would include a summary 
of performance test results and/or an engineering assessment related to 
the proposed removal of the design evaluation option in 40 CFR 
63.11496(g)(2) and table 5 to the CMAS NESHAP. The commenter stated 
that additional time is needed to conduct the performance test and that 
compiling some of the required submission information would involve 
significant effort. The commenter also noted that other major source 
rules, like the HON and PEPO Production NESHAP, provide 150 days after 
the effective date of the final rule to submit the NOCS report. 
Therefore, the commenter concluded, the final CMAS rule should also 
provide the same timeline.
    Response: The EPA agrees with the commenter that some sources may 
need to conduct performance testing which can take time to contract, 
execute, and obtain results. Additionally, the EPA acknowledges that 
the number of affected CMAS may strain the availability of resources 
for conducting the required performance tests. Therefore, the EPA is 
revising the final rule at 40 CFR 63.11496(f)(3)(ii) and 40 CFR 
63.11501(b) to extend the NOCS submission deadline to 150 days 
following the rule's effective date, although sources may submit prior 
to the deadline.
b. Wastewater
    Comment: A commenter objected to the EPA's proposal to remove the 
language at 40 CFR 63.11498(b) that exempts certain wastewater streams 
from the control requirements of item 2 in table 6 to the CMAS NESHAP 
during periods of startup and shutdown. The commenter stated that 
maintenance wastewater is typically generated during shutdown of 
process equipment; therefore, the elimination of the exemption would 
subject maintenance wastewater to the control requirements of item 2 in 
table 6 to the CMAS NESHAP. As such, the commenter requested that the 
EPA incorporate the HON's maintenance wastewater provisions at 40 CFR 
63.105 into the CMAS NESHAP. The commenter added that in the original 
HON rulemaking, the EPA acknowledged that maintenance wastewater was 
distinctly separate from process wastewater and should be managed 
through facility-specific procedures. Additionally, the commenter 
stated that determining the stream characteristics of maintenance 
wastewater is often difficult, given that a controlled drain system 
does not capture all maintenance wastewater.
    Response: The EPA considers the existing standards reasonable to 
address maintenance wastewater generated by CMAS CMPUs and therefore 
finds no need to incorporate the provisions at 40 CFR 63.105 into the 
CMAS NESHAP.
    40 CFR 63.11498(a) requires that all wastewater streams from a CMPU 
subject to the CMAS NESHAP comply with item 1 of table 6 to the CMAS 
NESHAP (i.e., owners and operators must discharge wastewater streams to 
onsite or offsite wastewater or hazardous waste treatment). According 
to 40 CFR 63.11498(a)(1), owners and operators of CMAS must understand 
the applicability of requirements to all wastewater streams, including 
maintenance wastewater, based on their concentration at all points in 
time. While the commenter is correct that 40 CFR 63.11498(b) previously 
stated that the requirements of item 2 of table 6 to the CMAS NESHAP 
did not apply during periods of startup or shutdown, that provision did 
not exempt sources from complying with the other aspects of 40 CFR 
63.11498 or table 6 to the CMAS NESHAP. Therefore, owners and operators 
should already know the concentration of most wastewater streams 
(including maintenance wastewater) from CMAS CMPUs, and those streams 
should already be captured and sent to treatment, as required by the 
original rule.\48\
---------------------------------------------------------------------------

    \48\ 74 FR 56008 (Oct. 29, 2009).
---------------------------------------------------------------------------

    For maintenance wastewater streams that contain partially soluble 
HAP at a concentration greater than or equal to 10,000 ppmw and 
separate water and organic phases, the EPA expects that facilities 
already have capture and control systems in place due to other 
wastewater restrictions (e.g., National Pollutant Discharge Elimination 
System permits, local publicly owned treatment works discharge 
criteria, etc.). Given these other applicable and existing wastewater 
restrictions, the EPA anticipates that owners and operators cannot 
discharge wastewater streams containing an unseparated water and 
organic phase or being treated as hazardous waste (per item 2.b. of 
table 6 to the CMAS NESHAP). Moreover, the EPA does not expect that 
facilities would change capture and control systems for these 
wastewater streams during periods of startup or shutdown. Accordingly, 
the EPA believes the removal of the exemption to control wastewater for 
periods of startup and shutdown from the CMAS NESHAP has no impact on 
CMAS facility operations and still ensures that a CAA section 112 
standard is in place at all times.
4. What is the rationale for our final approach and decisions regarding 
the other amendments for the CMAS categories?
    Based on the comments received for these other amendments, the EPA 
is generally finalizing all proposed requirements. In a few instances, 
the EPA received comments that led to additional minor editorial 
corrections and technical clarifications being made in the final rule. 
Section IV.D.3 of this preamble and the document entitled Summary of 
Public Comments and Responses for National Emission Standards for 
Hazardous Air Pollutants for Chemical Manufacturing Area Sources, which 
is in the docket for this rulemaking, contain the EPA's rationale for 
these corrections and technical clarifications.

V. Summary of Cost, Environmental, and Economic Impacts and Additional 
Analyses Conducted

A. What are the affected facilities?

    The EPA estimates that this final rule will affect 251 facilities 
subject to the CMAS NESHAP. The document entitled List of Facilities 
Subject to the CMAS NESHAP which is in the docket for this rulemaking, 
lists these facilities.\49\
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    \49\ Docket ID No. EPA-HQ-OAR-2024-0303-0028.
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B. What are the air quality impacts?

    This final action will reduce HAP and volatile organic compound 
(VOC) emissions from CMAS. The EPA estimates that the final amendments 
to the NESHAP will reduce overall HAP emissions from CMAS by 
approximately 160 tpy based on the finalized provisions detailed in 
sections III.A through C of this preamble. Additionally, the EPA 
estimates that the final amendments will reduce VOC emissions by 1,582 
tpy.
    The document entitled Economic Impact Analysis for the Final 
National Emission Standards for Hazardous Air Pollutants: Chemical 
Manufacturing Area Sources (which is in the docket for this 
rulemaking), the analyses referenced in sections IV.B through D of the 
proposal preamble, and the document entitled Updated Impact 
Calculations for the CMAS Categories--Final Rule (which is in the 
docket for this rulemaking) contain more information about the 
estimated

[[Page 16520]]

emissions reductions associated with this final rulemaking.

C. What are the cost impacts?

    The EPA estimates the costs of the final requirements detailed in 
sections III.A through III.C of this preamble will be approximately 
$18.4 million in total capital costs (in 2024 dollars for the entire 
period of analysis) and $5.7 million in total annual costs (including 
product recovery). The ``total annual costs'' are the sum of the 
annualized capital costs and other annual costs (e.g., operating and 
maintenance costs, recordkeeping and reporting costs). To obtain 
annualized capital costs, the EPA multiplies a capital recovery factor 
by the capital costs. The EPA bases the capital recovery factor on the 
lifetime of the capital equipment as well as the interest rate.
    The documents referenced in sections IV.B through IV.D of the 
preamble to the proposed rule and in the document entitled Updated 
Impact Calculations for the CMAS Categories--Final, which is in the 
docket for this rulemaking, contain more information about the 
estimated cost of this final action for the CMAS NESHAP.

D. What are the economic impacts?

    The document entitled Economic Impact Analysis for the Final 
National Emission Standards for Hazardous Air Pollutants: Chemical 
Manufacturing Area Sources, which is in the docket for this rulemaking, 
discusses expected economic impacts, including the impacts to small 
entities, of this final action.
    The EPA estimates the PV of the costs over the 15-year analytical 
period from 2027 to 2041 in accordance with Executive Orders 12866 and 
13563. Costs are in 2024 dollars, and the EPA discounts them to 2025 at 
3 and 7 percent discount rates per the recommendation in Office of 
Management and Budget (OMB) Circular A-4 (2003) and the EPA's 
Guidelines for Preparing Economic Analyses (2024).\50\ \51\ The EPA 
also presents the EAV at 3 and 7 percent discount rates. The EAV takes 
the non-uniform stream of costs (i.e., different costs in different 
years) and converts them into a single annual value that, if paid each 
year from 2027 to 2041, would equal the original stream of values in PV 
terms.
---------------------------------------------------------------------------

    \50\ https://www.whitehouse.gov/wp-content/uploads/2025/08/CircularA-4.pdf.
    \51\ https://www.epa.gov/system/files/documents/2024-12/guidelines-for-preparing-economic-analyses_final_508-compliant_compressed.pdf.
---------------------------------------------------------------------------

    The EPA estimates the PV of the costs over the 15-year period from 
2027 to 2041 including the value of product recovery (i.e., the cost 
savings) to be $72 million at a 3 percent discount rate and the EAV is 
$6.1 million. Additionally, the EPA estimates the PV of the costs 
including the value of product recovery to be $56 million at a 7 
percent discount rate and the EAV is $6.2 million.
    This final action impacts 55 small entities, which own a total of 
61 CMAS facilities. The EPA evaluates economic impacts of rulemakings 
on small entities by examining total annual cost estimates compared to 
the annual revenues of the companies (i.e., entities) that are the 
ultimate owners of the facilities affected by the rule. The EPA 
estimates cost-to-sales ratios, which are the total annual costs 
estimated for each entity divided by the entity's annual revenues. This 
ratio provides a measure of the direct economic impact to ultimate 
owners of CMAS facilities.
    The EPA estimates the average cost-to-sales ratio for small 
entities impacted by this final rule will be 0.18 percent with a 
maximum cost-to-sales ratio estimated at 1.37 percent, not considering 
the value of product recovery due to compliance. With product recovery, 
the EPA estimates that the average cost-to-sales ratio for small 
entities impacted by this final rule will be 0.14 percent with a 
maximum cost-to-sales ratio of 1.35 percent. The EPA estimates that 
approximately 5 percent of impacted small entities (three small 
entities out of a total of 55) will incur total annual costs greater 
than 1 percent of their annual revenue, and zero small entities will 
incur total annual costs greater than 3 percent of their annual 
revenue. The EPA does not anticipate that this final rule will have a 
substantial impact on a significant number of small entities. The EPA 
also does not expect this final rule to have significant market impacts 
or employment impacts. For more explanation of these economic impacts, 
refer to section VI.D of this preamble and the economic impact analysis 
accompanying this rulemaking.\52\
---------------------------------------------------------------------------

    \52\ Refer to the document entitled Economic Impact Analysis for 
the Final National Emission Standards for Hazardous Air Pollutants: 
Chemical Manufacturing Area Sources, available in the docket for 
this rulemaking.
---------------------------------------------------------------------------

E. What are the benefits?

    The emissions impacts estimated for this final include reductions 
in HAP emissions. In keeping with longstanding practice, the EPA did 
not monetize the benefits from the estimated HAP emission reductions 
associated with this final action. The EPA currently does not have 
sufficient methods to monetize benefits associated with HAP reductions 
and risk reductions for this rulemaking. While they are not monetized, 
the EPA expects that there will be health benefits associated with the 
estimated HAP emissions reductions. For additional information on the 
nonmonetized benefits of this rulemaking, refer to the economic impact 
analysis accompanying this rulemaking.\53\
---------------------------------------------------------------------------

    \53\ Id.
---------------------------------------------------------------------------

    The emission impacts estimated for this final action include net 
reductions in VOC emissions. Consistent with the proposed rulemaking, 
the EPA was not able to monetize the health and environmental impacts 
associated with the estimated changes in criteria air pollutant 
emissions for this final rule, which includes changes in VOC emissions, 
which impact the formation of ground-level ozone. Specifically, the EPA 
did not attempt to monetize the health benefits of reductions in HAP 
emissions in this analysis due to methodology and data limitations.

VI. Statutory and Executive Order Reviews

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

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

    This action is a significant regulatory action that the EPA 
submitted to the OMB for review. Any changes made in response to 
Executive Order 12866 review have been documented in the docket. The 
EPA prepared an economic analysis of the potential costs and benefits 
associated with this action. This analysis, Economic Impact Analysis 
for the Final National Emission Standards for Hazardous Air Pollutants: 
Chemical Manufacturing Area Sources, is in the docket for this 
rulemaking.

B. Executive Order 14192: Unleashing Prosperity Through Deregulation

    This action is considered an Executive Order 14192 de minimis 
regulatory action, rendering this action exempt from applicable 
Executive Order 14192 requirements.

C. Paperwork Reduction Act (PRA)

    The EPA submitted information collection activities in this rule 
for approval to OMB under the PRA. The ICR document that the EPA 
prepared has been assigned EPA ICR number 2323.10. You can find a copy 
of the ICR in the docket for this rulemaking, and it is briefly 
summarized here. The

[[Page 16521]]

information collection requirements are not enforceable until OMB 
approves them.
    The EPA is finalizing amendments to the CMAS NESHAP to add new 
monitoring requirements for heat exchange systems, add monitoring 
requirements for pressure vessels, add new monitoring practices for 
PRDs, clarify regulatory provisions for vent control bypasses, and add 
practices for instrument monitoring of equipment in organic HAP 
service. In addition, the EPA is finalizing amendments to the CMAS 
NESHAP that add requirements for electronic reporting of NOCS, periodic 
reports, and performance test results and make other minor 
clarifications and corrections. The EPA will collect this information 
to ensure compliance with the CMAS NESHAP.
    Respondents/affected entities: Owners or operators of CMAS 
facilities.
    Respondent's obligation to respond: Mandatory (40 CFR part 63, 
subpart VVVVVV).
    Estimated number of respondents: 251 (assumes 0 new respondents 
over the next three years).
    Frequency of response: Initially, semiannually, and annually.
    Total estimated burden: 10,700 hours (per year). Burden is defined 
at 5 CFR 1320.3(b).
    Total estimated cost: Average annual cost is $3,710,000 (per year) 
which includes $2,530,000 annualized capital or operation & maintenance 
costs.
    An agency may not conduct or sponsor, and a person is not required 
to respond to, a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for the 
EPA's regulations in 40 CFR are listed in 40 CFR part 9. When OMB 
approves this ICR, the EPA will announce that approval in the Federal 
Register and publish a technical amendment to 40 CFR part 9 to display 
the OMB control number for the approved information collection 
activities in this final rule.

D. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. The 
small entities subject to the requirements of this action are small 
businesses with the CMAS categories (see section II.A of this 
preamble). The EPA identified 55 small entities that this final action 
will affect. The EPA has determined that three of the 251 facilities in 
the CMAS categories affected by this final action may experience an 
impact greater than 1 percent of their total annual revenue. The EPA 
estimates that these three facilities will each incur approximately 
$81,000 in total capital costs and $31,000 in annual costs not 
including the value of product recovery (in 2024 dollars). Additional 
details of this analysis are presented in section V.D of this preamble 
and the document entitled Economic Impact Analysis for the Final 
National Emission Standards for Hazardous Air Pollutants: Chemical 
Manufacturing Area Sources, which is in the docket for this rulemaking.

E. Unfunded Mandates Reform Act (UMRA)

    This action does not contain an unfunded mandate of $100 million 
(adjusted annually for inflation) or more (in 1995 dollars) as 
described in UMRA, 2 U.S.C. 1531-1538, and does not significantly or 
uniquely affect small governments. The costs involved in this action 
are estimated not to exceed $187 million in 2024 dollars ($100 million 
in 1995 dollars adjusted for inflation using the GDP implicit price 
deflator) or more in any one year.

F. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the States, on the relationship between 
the national government and the States, or on the distribution of power 
and responsibilities among the various levels of government.

G. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    This action does not have Tribal implications as specified in 
Executive Order 13175. This action will not impose substantial direct 
compliance costs on Federally recognized Tribal governments nor preempt 
Tribal law. Thus, Executive Order 13175 does not apply to this action.
    Consistent with the EPA Policy on Consultation and Coordination 
with Indian Tribes, the EPA offered to consult with Tribal officials 
during the development of this action. A copy of that government-to-
government consultation offer is in a letter dated January 8, 2025, in 
the docket for this rulemaking.\54\
---------------------------------------------------------------------------

    \54\ Docket ID No. EPA-HQ-OAR-2024-0303-0037.
---------------------------------------------------------------------------

H. Executive Order 13045: Protection of Children From Environmental 
Health Risks and Safety Risks

    Executive Order 13045 directs Federal agencies to include an 
evaluation of the health and safety effects of the planned regulation 
on children in Federal health and safety standards and explain why the 
regulation is preferable to potentially effective and reasonably 
feasible alternatives. This action is not subject to Executive Order 
13045 because it is not a significant regulatory action under section 
3(f)(1) of Executive Order 12866, and because the EPA does not believe 
the environmental health or safety risks addressed by this action 
present a disproportionate risk to children. The final rule lowers HAP 
emissions and is projected to improve overall health for all 
individuals, including children.
    However, EPA's Policy on Children's Health applies to this action. 
The EPA does not believe this final action affecting the nine CMAS 
categories will result in a disproportionate impact to children's 
health. While the EPA is finalizing provisions that will reduce HAP 
emissions (see sections IV.A through IV.C of this preamble), these 
emission reductions will not benefit children more significantly than 
any other group.

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

    This action is not a ``significant energy action'' because it is 
not likely to have a significant adverse effect on the supply, 
distribution or use of energy. The EPA expects this final action would 
not reduce crude oil supply, fuel production, coal production, natural 
gas production, or electricity production. The EPA estimates that this 
final action would have minimal impact on the amount of imports or 
exports of crude oils, condensates, or other organic liquids used in 
the energy supply industries. Given the minimal impacts on energy 
supply, distribution, and use as a whole nationally, no significant 
adverse energy effects are expected to occur.

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

    This action involves technical standards. The EPA incorporates by 
reference and is finalizing VCS ASTM D6784-24, ``Standard Test Method 
for Elemental, Oxidized, Particle-Bound and Total Mercury Gas Generated 
from Coal-Fired Stationary Sources (Ontario Hydro Method)'' as an 
acceptable alternative to EPA Method 29 (referenced in the CMAS NESHAP 
at 40 CFR 63.11496(f)(3)(iii)) in this action with the following 
caveats. The EPA has approved this ASTM procedure as an alternative to 
EPA Method 29 only when the target compound is mercury,

[[Page 16522]]

and the ASTM procedure applies only to concentrations approximately 0.5 
to 100 micrograms per cubic meter. This test method was developed 
initially for the measurement of mercury in coal-fired power plants; 
however, it has also been extensively used on other stationary 
combustion sources including sources having a flue gas composition with 
high levels of hydrochloric acid and low levels of sulfur dioxide. The 
test method includes equipment and procedures for obtaining samples 
from effluent ducts and stacks, equipment and procedures for laboratory 
analysis, and procedures for calculating results of elemental, 
oxidized, particle-bound, and total mercury emissions. ASTM D6784-24 is 
available at ASTM International, 100 Barr Harbor Drive, P.O. Box C700, 
West Conshohocken, PA 19428-2959.\55\ The cost of obtaining these 
methods is not a significant financial burden, making the methods 
reasonably available to stakeholders.
---------------------------------------------------------------------------

    \55\ https://www.astm.org/.
---------------------------------------------------------------------------

    As discussed in the proposal preamble, the EPA conducted searches 
for the CMAS NESHAP through the Enhanced National Standards Systems 
Network Database managed by the American National Standards Institute. 
The EPA also conducted a review of voluntary consensus standards (VCS) 
organizations and accessed and searched their databases. The EPA 
conducted searches for EPA Methods 5, 5D, 21, and 29 of 40 CFR part 60, 
appendix A. During the EPA's VCS search, if the title or abstract (if 
provided) of the VCS described technical sampling and analytical 
procedures that are similar to the EPA's reference method, the EPA 
ordered a copy of the standard and reviewed it as a potential 
equivalent method. The EPA reviewed all potential standards to 
determine the practicality of the VCS for this rulemaking. This review 
requires significant method validation data that meet the requirements 
of EPA Method 301 for accepting alternative methods or scientific, 
engineering, and policy equivalence to procedures in the EPA reference 
methods. The EPA may reconsider determinations of impracticality when 
additional information is available for particular VCS.
    While the EPA identified seven other VCS as potentially applicable, 
the Agency decided these methods are impractical as alternatives 
because of the lack of equivalency, documentation, validation data, and 
other important technical and policy considerations. The EPA did not 
identify any applicable VCS for EPA Methods 5D and 21, and none were 
brought to its attention in comments. The EPA documented the search and 
review results in the document entitled Voluntary Consensus Standard 
Results for Technology Review of the National Emissions Standards for 
Hazardous Air Pollutants for Chemical Manufacturing Area Sources, which 
is in the docket for this rulemaking.\56\ Additional information for 
the VCS search and determinations is in this document.
---------------------------------------------------------------------------

    \56\ Docket ID No. EPA-HQ-OAR-2024-0303-0005.
---------------------------------------------------------------------------

K. Congressional Review Act (CRA)

    This action is subject to the CRA, and the EPA will submit a rule 
report to each House of the Congress and to the Comptroller General of 
the United States. This action is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

List of Subjects in 40 CFR Part 63

    Environmental protection, Administrative practice and procedures, 
Air pollution control, Hazardous substances, Incorporation by 
reference, Intergovernmental relations, Reporting and recordkeeping 
requirements.

Lee Zeldin,
Administrator.

    For the reasons stated in the preamble, the Environmental 
Protection Agency amends part 63 of title 40, chapter I, of the Code of 
Federal Regulations as follows:

PART 63--NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS 
FOR SOURCE CATEGORIES

0
1. The authority citation for part 63 continues to read as follows:

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

Subpart A--General Provisions

0
2. Amend Sec.  63.14 by:
0
a. Redesignating paragraphs (i)(106) through (120) as (i)(107) through 
(121); and
0
b. Adding new paragraph (i)(106).
    The addition reads as follows:


Sec.  63.14  Incorporations by reference.

* * * * *
    (i) * * *
    (106) ASTM D6784-24, Standard Test Method for Elemental, Oxidized, 
Particle-Bound and Total Mercury Gas Generated from Coal-Fired 
Stationary Sources (Ontario Hydro Method), Approved March 1, 2024; IBR 
approved for Sec.  63.11496(f).
* * * * *

Subpart VVVVVV--National Emission Standards for Hazardous Air 
Pollutants for Chemical Manufacturing Area Sources

0
3. Amend Sec.  63.11494 by revising paragraph (a)(2) introductory text, 
paragraphs (a)(2)(i), (c)(2)(iv), and (f) through (h) and adding 
paragraph (i) to read as follows:


Sec.  63.11494  What are the applicability requirements and compliance 
dates?

    (a) * * *
    (2) HAP listed in table 1 to this subpart (Table 1 HAP) are present 
in the CMPU, as specified in paragraph (a)(2)(i), (ii), (iii), or (iv) 
of this section.
    (i) The CMPU uses as feedstock, any material that contains 
quinoline, manganese, and/or trivalent chromium at an individual 
concentration greater than 1.0 percent by weight, or any other Table 1 
HAP at an individual concentration greater than 0.1 percent by weight. 
To determine the Table 1 HAP content of feedstocks, you may rely on 
formulation data provided by the manufacturer or supplier, such as the 
Safety Data Sheet (SDS) for the material. If the concentration in an 
SDS is presented as a range, use the upper bound of the range.
* * * * *
    (c) * * *
    (2) * * *
    (iv) Manufacture of chemicals classified using the 2007 version of 
NAICS code 325222, 325314, 325413, or 325998.
* * * * *
    (f) If you own or operate an existing affected source, you must 
achieve compliance with the applicable provisions in this subpart no 
later than March 21, 2013, except as specified otherwise in paragraph 
(i) of this section.
    (g) If you start up a new affected source on or before October 29, 
2009, you must achieve compliance with the applicable provisions of 
this subpart no later than October 29, 2009, except as specified 
otherwise in paragraph (i) of this section.
    (h) If you start up a new affected source after October 29, 2009, 
you must achieve compliance with the provisions in this subpart upon 
startup of your affected source, except as specified otherwise in 
paragraph (i) of this section.
    (i) All affected sources that commenced construction or 
reconstruction on or before January 22, 2025, must be in compliance 
with the requirements in Sec. Sec.  63.11495(a)(6), (b)(4), and (e), 
63.11496(e)(6)(iii), (f)(3)(iv), (f)(4), (g)(1)(iii), (g)(2)(ii), and 
(g)(4)(iii),

[[Page 16523]]

and 63.11499(d), item 5 to table 5 to this subpart, and item 1.c to 
table 8 to this subpart upon initial startup, or on April 1, 2029, 
whichever is later. All affected sources that commenced construction or 
reconstruction after January 22, 2025, must be in compliance with the 
requirements in Sec. Sec.  63.11495(a)(6), (b)(4), and (e), 
63.11496(e)(6)(iii), (f)(3)(iv), (f)(4), (g)(1)(iii), (g)(2)(ii), and 
(g)(4)(iii), and 63.11499(d), item 5 to table 5 to this subpart, and 
item 1.c to table 8 to this subpart upon initial startup, or on April 
1, 2026, whichever is later.

0
4. Amend Sec.  63.11495 by:
0
a. Revising paragraph (a) and paragraph (b) introductory text;
0
b. Adding paragraph (b)(4);
0
c. Revising paragraph (d); and
0
d. Adding paragraph (e).
    The revisions and additions read as follows:


Sec.  63.11495  What are the management practices and other 
requirements?

    (a) Management practices. If you have a CMPU subject to this 
subpart, you must comply with paragraphs (a)(1) through (6) of this 
section.
    (1) Each process vessel must be equipped with a cover or lid that 
must be closed at all times when it is in organic HAP service or metal 
HAP service, except for manual operations that require access, such as 
material addition and removal, inspection, sampling and cleaning. This 
requirement does not apply to process vessels containing only metal HAP 
that are in a liquid solution or other form that will not result in 
particulate emissions of metal HAP (e.g., metal HAP that is in ingot, 
paste, slurry, or moist pellet form or other form).
    (2) You must use any of the methods listed in paragraphs (a)(2)(i) 
through (iv) of this section to control total organic HAP emissions 
from transfer of liquids containing HAP listed in table 1 to this 
subpart to tank trucks or railcars. You are not required to comply with 
this paragraph (a)(2) if you have notified the Administrator in your 
initial notification that a material is reactive or resinous, and you 
will not be able to comply with any of the methods in paragraphs 
(a)(2)(i) through (iv) of this section for the transfer of such 
material.
    (i) Use submerged loading or bottom loading.
    (ii) Route emissions to a fuel gas system or process in accordance 
with Sec.  63.982(d).
    (iii) Vapor balance back to the storage tank or another storage 
tank connected by a common header.
    (iv) Vent through a closed-vent system to a control device.
    (3) Except as specified in paragraph (a)(6) of this section, you 
must conduct inspections of process vessels and equipment for each CMPU 
in organic HAP service or metal HAP service, as specified in paragraphs 
(a)(3)(i) through (v) of this section, to demonstrate compliance with 
paragraph (a)(1) of this section and to determine that the process 
vessels and equipment are sound and free of leaks. Alternatively, 
except when the subject CMPU contains metal HAP as particulate, 
inspections may be conducted while the subject process vessels and 
equipment are in VOC service, provided that leaks can be detected when 
in VOC service.
    (i) Inspections must be conducted at least quarterly.
    (ii) For these inspections, detection methods incorporating sight, 
sound, or smell are acceptable. Indications of a leak identified using 
such methods constitute a leak unless you demonstrate that the 
indications of a leak are due to a condition other than loss of HAP. If 
indications of a leak are determined not to be HAP in one quarterly 
monitoring period, you must still perform the inspection and 
demonstration in the next quarterly monitoring period.
    (iii) As an alternative to conducting inspections, as specified in 
paragraph (a)(3)(ii) of this section, you may use Method 21 of 40 CFR 
part 60, appendix A-7, with a leak definition of 500 ppmv to detect 
leaks. You may also use Method 21 with a leak definition of 500 ppmv to 
determine if indications of a leak identified during an inspection 
conducted in accordance with paragraph (a)(3)(ii) of this section are 
due to a condition other than loss of HAP. The procedures in this 
paragraph (a)(3)(iii) may not be used as an alternative to the 
inspection required by paragraph (a)(3)(ii) of this section for process 
vessels that contain metal HAP as particulate.
    (iv) Inspections must be conducted while the subject CMPU is 
operating.
    (v) No inspection is required in a calendar quarter during which 
the subject CMPU does not operate for the entire calendar quarter and 
is not in organic HAP service or metal HAP service. If the CMPU 
operates at all during a calendar quarter, an inspection is required.
    (4) Except as specified in paragraph (a)(6) of this section, you 
must repair any leak within 15 calendar days after detection of the 
leak, or document the reason for any delay of repair. For the purposes 
of this paragraph (a)(4), a leak will be considered ``repaired'' if a 
condition specified in paragraph (a)(4)(i), (ii), or (iii) of this 
section is met.
    (i) The visual, audible, olfactory, or other indications of a leak 
to the atmosphere have been eliminated; or
    (ii) No bubbles are observed at potential leak sites during a leak 
check using soap solution; or
    (iii) The system will hold a test pressure.
    (5) Except as specified in paragraph (a)(6) of this section, you 
must keep records of the dates and results of each inspection event, 
the dates of equipment repairs, and, if applicable, the reasons for any 
delay in repair.
    (6) Beginning no later than the compliance dates specified in Sec.  
63.11494(i) for equipment in organic HAP service, as determined by 
Sec.  63.180(d), paragraphs (a)(3) through (5) of this section no 
longer apply. Instead, you must comply with the requirements specified 
in paragraphs (a)(6)(i) through (xiv) of this section. Equipment that 
is in vacuum service is excluded from the requirements of this 
paragraph (a)(6). Equipment that is in organic HAP service less than 
300 hours per calendar year is excluded from the requirements of this 
paragraph (a)(6) if it is identified as required in Sec.  
63.11501(c)(9)(i)(D).
    (i) Except as specified in paragraph (a)(6)(ii) of this section, 
conduct leak detection monitoring annually for 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 as specified in paragraphs (a)(6)(i)(A) through (C) of this 
section.
    (A) Use the method specified in Sec.  63.180(b)(1) through (3).
    (B) The calibration gases must be zero air (less than 10 ppm of 
hydrocarbon in air); and methane and air at a concentration of 10,000 
ppm methane. At the end of each monitoring day, check the instrument 
using the same calibration gas that was used to calibrate the 
instrument before use. Follow the procedures specified in Method 21 of 
40 CFR part 60, appendix A-7, section 10.1, except do not adjust the 
meter readout to correspond to the calibration gas value. If multiple 
scales are used, record the instrument reading for each scale used. 
Divide the arithmetic difference of the initial and post-test 
calibration response by the corresponding calibration gas value for 
each scale and multiply by 100 to express the calibration drift as a 
percentage. If a calibration drift assessment shows a negative drift of 
more than 10 percent, then re-monitor all equipment monitored since the 
last calibration with instrument readings between the leak definition 
and the leak definition multiplied by (100 minus the

[[Page 16524]]

percent of negative drift) divided by 100. If any calibration drift 
assessment shows a positive drift of more than 10 percent from the 
initial calibration value, then, at your discretion, all equipment with 
instrument readings above the leak definition and below the leak 
definition multiplied by (100 plus the percent of positive drift) 
divided by 100 monitored since the last calibration may be re-
monitored.
    (C) The instrument reading that defines a leak is 10,000 ppm or 
greater. When a leak is detected, the following requirements apply:
    (1) Clearly identify the leaking equipment. A weatherproof and 
readily visible identification, marked with the equipment 
identification number, must be attached to the leaking equipment. The 
identification on the equipment may be removed after it is repaired.
    (2) A first attempt at repair must be made no later than 5 calendar 
days after the leak is detected.
    (3) The piece of equipment must be repaired as soon as practicable, 
but no later than 15 calendar days after the leak is detected, except 
as provided in paragraph (a)(6)(viii) of this section.
    (4) The leak is repaired when instrument re-monitoring of the 
equipment does not detect a leak.
    (5) It is a deviation to fail to take action to repair the leaks 
within the specified time. If action is taken to repair the leaks 
within the specified time, failure of that action to successfully 
repair the leak is not a deviation. However, if the repairs are 
unsuccessful, a leak is detected and you must take further action as 
required by applicable provisions of this paragraph (a)(6).
    (ii) The following types of equipment are exempt from the 
monitoring requirements specified in paragraph (a)(6)(i) of this 
section if the equipment meets one of the requirements in paragraphs 
(a)(6)(ii)(A) through (E) of this section.
    (A) Any pump in light liquid service, valve in gas/vapor service or 
light liquid service, or connector in gas/vapor service or light liquid 
service that is designated as unsafe-to-monitor if:
    (1) You determine that the pump, valve, or connector is unsafe to 
monitor because monitoring personnel would be exposed to an immediate 
danger as a consequence of complying with paragraph (a)(6)(i) of this 
section; and
    (2) You have a written plan that requires monitoring of the pump, 
valve, or connector as frequently as practical during safe-to-monitor 
times, but not more frequently than the annual leak detection 
monitoring.
    (B) Any pump in light liquid service if it meets one of the 
requirements in Sec.  63.163(e)(1) through (6), (f), or (g). If the 
pump is located within the boundary of an unmanned plant site then it 
is exempt from the weekly visual inspection requirement of Sec.  
63.163(e)(4), and the daily requirements of Sec.  63.163(e)(5), 
provided that each pump is visually inspected as often as practicable 
and at least monthly.
    (C) Any valve in gas/vapor service or light liquid service that is 
designated as a difficult-to-monitor valve if:
    (1) You determine that the valve cannot be monitored without 
elevating the monitoring personnel more than 2 meters above a support 
surface or it is not accessible at anytime in a safe manner;
    (2) The CMPU within which the valve is located is an existing 
source or you designate less than 3 percent of the total number of 
valves in a new source as difficult-to-monitor; and
    (3) You follow a written plan that requires monitoring of the valve 
as frequently as practical, but not more frequently than the annual 
leak detection monitoring.
    (D) Any connector in gas/vapor service or light liquid service that 
is designated as an unsafe-to-repair connector if:
    (1) You determine that repair personnel would be exposed to an 
immediate danger as a consequence of complying with paragraph (a)(6)(i) 
of this section; and
    (2) The connector will be repaired before the end of the next 
scheduled CMPU shutdown.
    (E) Any connector in gas/vapor service or light liquid service that 
is inaccessible or is ceramic or ceramic-lined (e.g., porcelain, glass, 
or glass-lined); however, if any inaccessible or ceramic or ceramic-
lined connector is observed by visual, audible, olfactory, or other 
means to be leaking, a first attempt at repair must be made no later 
than 5 calendar days after the leak is detected. The leak must be 
repaired as soon as practicable, but no later than 15 calendar days 
after the leak is detected, except as provided in paragraphs 
(a)(6)(viii) and (a)(6)(ii)(D) of this section. An inaccessible 
connector is defined in Sec.  63.11502(b).
    (iii) For compressors, comply with the requirements in Sec.  
63.164.
    (iv) For pressure relief devices in gas/vapor service or light 
liquid service, comply with the requirements in Sec.  63.165(e)(1) 
through (8), except as specified in paragraphs (a)(6)(iv)(A) through 
(D) of this section.
    (A) Substitute ``violation'' with ``deviation''.
    (B) Section 63.165(e)(3)(v)(D) does not apply.
    (C) Substitute each occurrence of April 25, 2023 with April 1, 
2026.
    (D) Substitute the occurrence of July 15, 2027 with April 1, 2029.
    (v) For sampling connection systems, comply with the requirements 
in Sec.  63.166.
    (vi) For open-ended valves or lines, comply with the requirements 
in Sec.  63.167.
    (vii) For pumps, valves, connectors, and agitators in heavy liquid 
service; instrumentation systems; and pressure relief devices in liquid 
service, comply with the requirements in Sec.  63.169 except a leak is 
detected if the instrument reading equals or exceeds 10,000 ppmv for 
pumps, valves, and connectors instead of the leak definitions specified 
in Sec.  63.169(b).
    (viii) For delay of repair, comply with the requirements in Sec.  
63.171 except the phrase ``Except as specified in paragraph (f) of this 
section,'' and Sec.  63.171(f) do not apply.
    (ix) For closed vent systems and control devices, comply with the 
requirements in Sec.  63.172 except as specified in paragraphs 
(a)(6)(ix)(A) through (G) of this section.
    (A) Substitute ``Sec.  63.162(b) of this subpart'' with ``paragraph 
(a)(6)(xi) of this section''.
    (B) Section 63.172(d) does not apply.
    (C) Flares used to comply with this paragraph (a)(6) must comply 
with the requirements in subpart SS of this part.
    (D) Substitute ``violation'' with ``deviation''.
    (E) Substitute ``For each source as defined in Sec.  63.101, and 
for each source as defined in Sec.  63.191, beginning no later than the 
compliance dates specified in Sec.  63.100(k)(10)'' with ``For each 
affected source as described in Sec.  63.11494(d), beginning no later 
than the compliance dates specified in Sec.  63.11494(i)''.
    (F) Substitute ``After the compliance dates specified in Sec.  
63.100 of subpart F of this part'' with ``After the compliance dates 
specified in Sec.  63.11494(i)''.
    (G) Substitute ``periodic report required by Sec.  63.182(d)'' with 
``semiannual compliance report required by paragraph (a)(6)(xiv) of 
this section''.
    (x) For agitators in gas/vapor service and in light liquid service, 
comply with the requirements in Sec.  63.173.
    (xi) You may use the alternative means of emission limitation 
provided in Sec. Sec.  63.178 and 63.179. You may also request a 
determination of alternative means of emission limitation to the 
requirements in this paragraph (a)(6) as provided in Sec.  63.177. If 
the

[[Page 16525]]

Administrator makes a determination that an alternative means of 
emission limitation is permissible, you must comply with the 
alternative.
    (A) Substitute ``Sec. Sec.  63.163 through 63.171 and Sec. Sec.  
63.173 through 63.176'' and ``Sec.  63.163, through 63.171, and 
Sec. Sec.  63.173 and 63.174 of this subpart'' with ``paragraphs 
(a)(6)(i) through (viii) and (x) of this section''.
    (B) Substitute ``Sec.  63.181'' with ``Sec.  63.11501(c)(9)''.
    (C) Substitute ``Sec.  63.163, Sec. Sec.  63.168 and 63.169, and 
Sec. Sec.  63.173 through 63.176 of this subpart'' with ``paragraphs 
(a)(6)(i), (ii), and (vii) through (x) of this section''.
    (D) Substitute ``Sec.  63.180(b) of this subpart'' with ``paragraph 
(a)(6)(i)(A) and (B) of this section''.
    (E) Substitute ``Sec. Sec.  63.163 through 63.170, and Sec. Sec.  
63.172 through 63.176 of this subpart'' with ``paragraphs (a)(6)(i) 
through (vii), (ix), and (x) of this section''.
    (F) Substitute ``Sec.  63.174 of this subpart'' with ``paragraph 
(a)(6)(i) of this section''.
    (G) Section 63.178(c)(3)(iii) and (iv) does not apply.
    (H) Substitute ``Sec.  63.172 of this subpart'' with ``paragraph 
(a)(6)(ix) of this section''.
    (xii) Keep records as specified in Sec.  63.11501(c)(9).
    (xiii) Submit the Notification of Compliance Status as specified in 
Sec.  63.11501(b)(6).
    (xiv) Submit the Semiannual Compliance Report as specified in Sec.  
63.11501(d)(9).
    (b) Small heat exchange systems. For each heat exchange system 
subject to this subpart with a cooling water flow rate less than 8,000 
gallons per minute (gal/min) and not meeting one or more of the 
conditions in Sec.  63.104(a)(1) through (4), you must comply with 
paragraphs (b)(1) through (4) of this section, or as an alternative, 
you may comply with any one of the requirements in item 1.a, 1.b, or 
1.c of table 8 to this subpart. Beginning on April 1, 2029, for 
purposes of compliance with this paragraph (b), Sec.  63.104(a)(3) and 
(4) no longer apply.
* * * * *
    (4) Beginning no later than the compliance dates specified in Sec.  
63.11494(i), you must not inject water into or dispose of water in the 
heat exchange system if the water is considered wastewater as defined 
in Sec.  63.11502.
* * * * *
    (d) General duty. At all times, you must operate and maintain any 
affected CMPU, including associated air pollution control equipment and 
monitoring equipment, in a manner consistent with safety and good air 
pollution control practices for minimizing emissions. The general duty 
to minimize emissions does not require the owner or operator to make 
any further efforts to reduce emissions if levels required by the 
applicable standard have been achieved. Determination of whether such 
operation and maintenance procedures are being used will be based on 
information available to the Administrator, which may include, but is 
not limited to, monitoring results, review of operation and maintenance 
procedures, review of operation and maintenance records, and inspection 
of the CMPU.
    (e) Bypass provisions. Beginning no later than the compliance dates 
specified in Sec.  63.11494(i), the use of a bypass line at any time on 
a closed vent system to divert emissions subject to any of the 
requirements in Sec. Sec.  63.11495 through 63.11498 to the atmosphere, 
or to a control device not meeting the requirements specified in 
Sec. Sec.  63.11495 through 63.11498, is an emissions standards 
deviation. If you are subject to the bypass monitoring requirements of 
Sec.  63.983(a)(3), then you must continue to comply with the 
requirements in Sec.  63.983(a)(3) and the recordkeeping and reporting 
requirements in Sec. Sec.  63.998(d)(1)(ii) and 63.999(c)(2)(ii) and 
(iii), except the phrase ``Except for equipment needed for safety 
purposes such as pressure relief devices, low leg drains, high point 
bleeds, analyzer vents, and open-ended valves or lines'' in Sec.  
63.983(a)(3) does not apply. Instead, the exemptions specified in 
paragraphs (e)(1) and (2) of this section apply. Owners or operators of 
closed-vent systems and control devices used to comply with the 
equipment leak provisions specified in paragraph (a)(6)(ix) of this 
section are not subject to this paragraph (e).
    (1) Except for pressure relief devices subject to Sec.  
63.165(e)(4), equipment such as low leg drains and equipment subject to 
the requirements specified in paragraph (a)(6) of this section are not 
subject to this paragraph (e).
    (2) Open-ended valves or lines that use a cap, blind flange, plug, 
or second valve and follow the requirements specified in 40 CFR 60.482-
6(a)(2), (b), and (c) or follow requirements codified in another 
regulation that are the same as 40 CFR 60.482-6(a)(2), (b), and (c) are 
not subject to this paragraph (e).

0
5. Amend Sec.  63.11496 by:
0
a. Revising paragraphs (a)(3), (e)(6), (f)(3) through (5), and (g)(1) 
through (4); and
0
b. Removing and reserving paragraph (g)(5).
    The revisions read as follows:


Sec.  63.11496  What are the standards and compliance requirements for 
process vents?

    (a) * * *
    (3) If your current estimate is that emissions from batch process 
vents from a CMPU are less than 10,000 lb/yr, then you must keep a 
record of the number of batches of each process operated per month. 
Also, you must reevaluate your total emissions from batch process vents 
prior to making any process changes that affect emission calculations 
in paragraphs (a)(1) and (2) of this section. If projected emissions 
increase to 10,000 lb/yr or more, you must be in compliance with the 
options for batch process vents in table 2 to this subpart upon 
initiating operation under the new operating conditions. You must 
maintain records documenting the results of all updated emissions 
calculations.
* * * * *
    (e) * * *
    (6) Except as specified in paragraphs (e)(6)(i) through (iii) of 
this section, the CEMS requirements and data reduction requirements for 
CEMS specified in Sec.  63.2450(j) apply.
    (i) Substitute April 1, 2026'' for ``August 12, 2020'' in Sec.  
63.2450(j)(1).
    (ii) Section 63.2450(j)(3) does not apply. Instead, you must 
conduct a performance evaluation of each CEMS according to the 
requirements in Sec.  63.8 and according to the applicable Performance 
Specification of 40 CFR part 60, appendix B, except that the schedule 
in Sec.  63.8(e)(4) does not apply, and before January 22, 2025, the 
results of the performance evaluation must be included in the 
notification of compliance status report. Beginning on and after 
January 22, 2025, the results of the performance evaluation must be 
submitted in accordance with Sec.  63.2520(g).
    (iii) Substitute ``Sec.  63.11494(i)'' for each occurrence of 
``Sec.  63.2445(g)''.
    (f) * * *
    (3) If you have an existing source subject to the HAP metals 
emission limits specified in table 4 to this subpart, you must comply 
with the initial and continuous compliance and monitoring requirements 
in paragraphs (f)(3)(i) through (iv) of this section. You must keep 
records of monitoring results to demonstrate continuous compliance.
    (i) You must prepare a monitoring plan containing the information 
in paragraphs (f)(3)(i)(A) through (E) of this section. The plan must 
be maintained on-site and be available on request. You

[[Page 16526]]

must operate and maintain the control device according to a site-
specific monitoring plan at all times.
    (A) A description of the device;
    (B) Results of a performance test or engineering assessment 
conducted in accordance with paragraph (f)(3)(ii) of this section 
verifying the performance of the device for reducing HAP metals or 
particulate matter (PM) to the levels required by this subpart;
    (C) Operation and maintenance plan for the control device 
(including a preventative maintenance schedule consistent with the 
manufacturer's instructions for routine and long-term maintenance) and 
continuous monitoring system (CMS);
    (D) A list of operating parameters that will be monitored to 
maintain continuous compliance with the applicable emissions limits; 
and
    (E) Operating parameter limits based on either monitoring data 
collected during the performance test or established in the engineering 
assessment.
    (ii) Except as specified in paragraph (f)(3)(iv) of this section, 
you must conduct a performance test or an engineering assessment for 
each CMPU subject to a HAP metals emissions limit in table 4 to this 
subpart and on or before June 1, 2026 report the results in your 
Notification of Compliance Status (NOCS), after June 1, 2026 include a 
summary of results of a performance test submitted according to 
paragraph (g)(1)(iv) of this section and the results of an engineering 
assessment in your NOCS. If the performance test was not submitted 
according to paragraph (g)(1)(iv) of this section, submit the complete 
report with the NOCS. Each performance test or engineering assessment 
must be conducted under representative operating conditions, and 
sampling for each performance test must be conducted at both the inlet 
and outlet of the control device. You may not conduct performance tests 
during periods of malfunction. You must record the process information 
that is necessary to document operating conditions during the test and 
include in such record an explanation to support that such conditions 
represent the entire range of normal operation, including operational 
conditions for maximum emissions if such emissions are not expected 
during maximum production. You shall make available to the 
Administrator such records as may be necessary to determine the 
conditions of performance tests. If you own or operate an existing 
affected source, you are not required to conduct the initial 
performance test if a prior performance test was conducted within the 5 
years prior to the effective date using the same methods specified in 
paragraph (f)(3)(iii) of this section, and, either no process changes 
have been made since the test, or, if you can demonstrate that the 
results of the performance test, with or without adjustments, reliably 
demonstrate compliance despite process changes.
    (iii) Except as specified in paragraph (f)(3)(iv) of this section, 
if you elect to conduct a performance test, it must be conducted 
according to requirements in Sec.  63.11410(j)(1). As an alternative to 
conducting a performance test using Method 5 or 5D to determine the 
concentration of PM, you may use Method 29 of 40 CFR part 60, appendix 
A-8 of this chapter to determine the concentration of HAP metals. ASTM 
D6784-24 (incorporated by reference, see Sec.  63.14) may also be used 
in lieu of Method 29, if the target compound is mercury and 
concentrations are approximately 0.5 to 100 micrograms per cubic meter. 
You have demonstrated compliance if the overall reduction of either HAP 
metals or total PM is equal to or greater than 95 percent.
    (iv) Beginning on the compliance dates specified in Sec.  
63.11494(i), the option to use an engineering assessment (as specified 
in paragraph (f)(3)(ii) of this section for determining compliance with 
a HAP metals emissions limit in table 4 to this subpart) no longer 
applies. Instead, you must comply with the performance test 
requirements in paragraphs (f)(3)(ii) and (iii) of this section. If a 
performance test has never been conducted, conduct an initial 
performance test no later than the compliance dates specified in Sec.  
63.11494(i) or within 180 days after startup of the source, whichever 
is later. Begin conducting subsequent performance tests no later than 
the compliance dates specified in Sec.  63.11494(i) or 60 calendar 
months after the previous performance test, whichever is later.
    (4) If you have a new source using a baghouse as a control device, 
you must install, operate, and maintain a bag leak detection system on 
all baghouses used to comply with the HAP metals emissions limit in 
table 4 to this subpart. You must comply with the testing, monitoring, 
and recordkeeping requirements in Sec.  63.11410(g), (i), and (j)(1), 
except you are not required to submit the monitoring plan required by 
Sec.  63.11410(g)(2) for approval. If a performance test has never been 
conducted, conduct an initial performance test no later than the 
compliance dates specified in Sec.  63.11494(i) or within 180 days 
after startup of the source, whichever is later. Begin conducting 
subsequent performance tests no later than the compliance dates 
specified in Sec.  63.11494(i) or 60 calendar months after the previous 
performance test, whichever is later.
    (5) If you have a new source using a control device other than a 
baghouse to comply with the HAP metals emission limits in table 4 to 
this subpart, you must comply with the initial and continuous 
compliance and monitoring requirements in paragraphs (f)(3)(i) through 
(iv) of this section.
    (g) * * *
    (1) Requirements for performance tests. (i) If you are complying 
with a percent reduction, mass emission limit, or outlet concentration 
performance standard in table 2 to this subpart for batch process vents 
or in table 3 to this subpart for continuous process vents, then the 
requirements specified in paragraphs (g)(1)(ii) through (iv) of this 
section and in Sec.  63.2450(g)(1) through (4) apply instead of, or in 
addition to, the requirements specified in subpart SS of this part.
    (ii) Upon request, you shall make available to the Administrator, 
such records as may be necessary to determine the conditions of 
performance tests.
    (iii) If a performance test has never been conducted, conduct an 
initial performance test no later than 180 days after the compliance 
dates specified in Sec.  63.11494(i). Begin conducting subsequent 
performance tests no later than 180 days after the compliance dates 
specified in Sec.  63.11494(i) or 60 calendar months after the previous 
performance test, whichever is later. You must record the process 
information that is necessary to document operating conditions during 
the test and include in such record an explanation to support that such 
conditions represent the entire range of normal operation, including 
operational conditions for maximum emissions if such emissions are not 
expected during maximum production. The owner or operator may not 
conduct performance tests during periods of malfunction.
    (iv) Beginning on June 1, 2026 within 60 days after the date of 
completing each performance test required by this subpart, you must 
submit the results of the performance test following the procedure 
specified in Sec.  63.9(k). Submit the data in a file format generated 
using the EPA's Electronic Reporting Tool (ERT). Alternatively, you may 
submit an electronic file consistent with the extensible markup 
language (XML) schema listed on the EPA's ERT website (https://
www.epa.gov/electronic-reporting-air-emissions/electronic-

[[Page 16527]]

reporting-tool-ert) accompanied by the other information required by 
Sec.  63.7(g)(2) in PDF format.
    (2) Design evaluation. (i) Except as specified in paragraph 
(g)(2)(ii) of this section, to determine initial compliance with a 
percent reduction or outlet concentration emission limit, you may elect 
to conduct a design evaluation as specified in Sec.  63.1257(a)(1) 
instead of a performance test as specified in subpart SS of this part. 
You must establish the value(s) and basis for the operating limits as 
part of the design evaluation. For continuous process vents, the design 
evaluation must be conducted at maximum representative operating 
conditions for the process, unless the Administrator specifies or 
approves alternate operating conditions. For batch process vents, the 
design evaluation must be conducted under worst-case conditions, as 
specified in Sec.  63.2460(c)(2).
    (ii) Beginning on the compliance dates specified in Sec.  
63.11494(i), paragraph (g)(2)(i) of this section does not apply. 
Instead, the owner or operator must comply with the performance test 
requirements in paragraph (g)(1) of this section.
    (3) Outlet concentration correction for combustion devices. When 
Sec.  63.997(e)(2)(iii)(C) requires you to correct the measured 
concentration at the outlet of a combustion device to 3 percent oxygen 
if you add supplemental combustion air, the requirements in either 
paragraph (g)(3)(i) or (ii) of this section apply for the purposes of 
this subpart.
    (i) You must correct the concentration in the gas stream at the 
outlet of the combustion device to 3 percent oxygen if you add 
supplemental gases, as defined in Sec.  63.2550, to the vent stream, 
or;
    (ii) You must correct the measured concentration for supplemental 
gases using equation 1 to Sec.  63.2460(e)(6); you may use process 
knowledge and representative operating data to determine the fraction 
of the total flow due to supplemental gas.
    (4) Continuous parameter monitoring. The provisions in Sec.  
63.2450(k)(1) through (7) apply in addition to the requirements for 
continuous parameter monitoring systems (CPMS) in subpart SS of this 
part, except as specified in paragraphs (g)(4)(i) through (iii) of this 
section.
    (i) You may measure pH or caustic strength of the scrubber effluent 
at least once per day for any halogen scrubber within a CMPU subject 
this section.
    (ii) The requirements in Sec.  63.2450(k)(6) to request approval of 
a procedure to monitor operating parameters does not apply for the 
purposes of this subpart. You must provide the required information in 
your NOCS report required by Sec.  63.11501(b).
    (iii) In Sec.  63.2450(k)(7), substitute ``Sec.  63.11494(i)'' for 
``Sec.  63.2445(g)''.
* * * * *

0
6. Amend Sec.  63.11497 by revising paragraphs (a) and (c) and adding 
paragraphs (e) and (f) to read as follows:


Sec.  63.11497  What are the standards and compliance requirements for 
storage tanks?

    (a) Organic HAP emissions from storage tanks. You must comply with 
the emission limits and other requirements in table 5 to this subpart 
and in paragraphs (b) through (f) of this section for organic HAP 
emissions from each of your storage tanks that meet the applicability 
criteria in table 5 to this subpart.
* * * * *
    (c) SSM provisions. References to SSM provisions in subparts that 
are referenced in paragraphs (a) or (b) of this section or table 5 to 
this subpart do not apply.
* * * * *
    (e) Pressure vessels. If you are required to comply with this 
paragraph (e) as specified in item 5 of table 5 to this subpart (for 
each pressure vessel with a design capacity greater than or equal to 
20,000 gallons), you must operate and maintain the pressure vessel, as 
specified in paragraphs (e)(1) through (5) of this section.
    (1) The pressure vessel must be designed to operate with no 
detectable emissions at all times.
    (2) Except for equipment that meet the criteria specified in Sec.  
63.11495(a)(6)(ii)(A) (for valves, connectors, and pumps in gas/vapor 
service and in light liquid service that are unsafe to monitor), Sec.  
63.11495(a)(6)(ii)(C) (for valves in gas/vapor service and in light 
liquid service that are difficult-to-monitor), and Sec.  
63.11495(a)(6)(ii)(E) (for connectors in gas/vapor service and in light 
liquid service that are inaccessible or ceramic or ceramic-lined), you 
must monitor each point on the pressure vessel through which organic 
HAP could potentially be emitted by conducting initial and annual 
performance tests using Method 21 of appendix A-7 to part 60 of this 
chapter.
    (3) Each instrument reading greater than 500 ppmv is a deviation.
    (4) Estimate the flow rate and total regulated material emissions 
from the defect. Assume the pressure vessel has been emitting for half 
of the time since the last performance test, unless other information 
supports a different assumption.
    (5) Whenever organic HAP are in the pressure vessel, you must 
operate the pressure vessel as a closed system that vents through a 
closed vent system to either a control device (other than a flare) in 
accordance with Sec.  63.982(c); or a flare in accordance with Sec.  
63.982(b). For purposes of compliance with this paragraph, a release of 
organic HAP through a pressure vessel's pressure relief device to the 
atmosphere is a deviation.
    (f) Exceptions and alternatives to subpart SS of this part. If you 
are complying with a percent reduction, mass emission limit, or outlet 
concertation performance standard in table 5 to this subpart for 
storage tanks, then the provisions in paragraphs (f)(1) and (2) of this 
section apply in addition to the provisions in subpart SS of this part.
    (1) Requirements for performance tests. (i) The requirements 
specified in paragraphs (f)(1)(ii) through (iv) of this section apply 
instead of, or in addition to, the requirements specified in subpart SS 
of this part.
    (ii) Upon request, you shall make available to the Administrator, 
such records as may be necessary to determine the conditions of 
performance tests.
    (iii) If a performance test has never been conducted, conduct an 
initial performance test no later than 180 days after the compliance 
dates specified in Sec.  63.11494(i). Begin conducting subsequent 
performance tests no later than 180 days after the compliance dates 
specified in Sec.  63.11494(i) or 60 calendar months after the previous 
performance test, whichever is later. You must record the process 
information that is necessary to document operating conditions during 
the test and include in such record an explanation to support that such 
conditions represent the entire range of normal operation, including 
operational conditions for maximum emissions if such emissions are not 
expected during maximum production.
    (iv) Beginning on June 1, 2026, within 60 days after the date of 
completing each performance test required by this subpart, you must 
submit the results of the performance test following the procedure 
specified in Sec.  63.9(k). Submit the data in a file format generated 
using the EPA's Electronic Reporting Tool (ERT). Alternatively, you may 
submit an electronic file consistent with the extensible markup 
language (XML) schema listed on the EPA's ERT website (https://
www.epa.gov/electronic-

[[Page 16528]]

reporting-air-emissions/electronic-reporting-tool-ert) accompanied by 
the other information required by Sec.  63.7(g)(2) in PDF format.
    (2) Design evaluation. Beginning on the compliance dates specified 
in Sec.  63.11494(i), the option to use a design evaluation to 
demonstrate compliance in Sec.  63.985(b)(1)(i) does not apply. 
Instead, the owner or operator must comply with the performance test 
requirements in Sec.  63.985(b)(1)(ii) and paragraph (f)(1) of this 
section.

0
7. Amend Sec.  63.11498 by revising paragraph (a) introductory text and 
paragraph (b) to read as follows:


Sec.  63.11498  What are the standards and compliance requirements for 
wastewater systems?

    (a) You must comply with the requirements in paragraph (a)(1) and 
(2) of this section and in table 6, item 1 to this subpart for all 
wastewater streams from a CMPU subject to this subpart. If the 
partially soluble HAP concentration in a wastewater stream is equal to 
or greater than 10,000 ppmw and the wastewater stream contains a 
separate organic phase, then you must also comply with table 6, item 2 
to this subpart for that wastewater stream. Partially soluble HAP are 
listed in table 7 to this subpart.
* * * * *
    (b) References to SSM provisions in subparts that are referenced in 
paragraph (a) of this section or table 6 to this subpart do not apply.

0
8. Amend Sec.  63.11499 by revising paragraph (a) and adding paragraph 
(d) to read as follows:


Sec.  63.11499  What are the standards and compliance requirements for 
heat exchange systems?

    (a) Except as specified in paragraph (d) of this section, if the 
cooling water flow rate in your heat exchange system is equal to or 
greater than 8,000 gal/min and is not meeting one or more of the 
conditions in Sec.  63.104(a)(1) through (4), then you must comply with 
one of the requirements specified in table 8 to this subpart.
* * * * *
    (d) If you are required to comply with the requirements in Sec.  
63.104(f) through (j) and (l) as specified in item 1.c of table 8 to 
this subpart (for heat exchange systems with a cooling water flow rate 
greater than or equal to 8,000 gal/min), then you must also comply with 
the requirements in paragraphs (d)(1) through (6) of this section.
    (1) Replace each occurrence of ``For each source as defined in 
Sec.  63.101,'' with ``For each affected source as described in Sec.  
63.11494(d),''.
    (2) Replace each reference to Sec.  63.100(k)(10) with Sec.  
63.11494(i).
    (3) Replace each occurrence of ``semi-annual periodic report 
required by Sec.  63.152(c)'', ``semi-annual periodic report'', or 
``periodic report'' with ``semiannual compliance report''.
    (4) The phrase ``Except as specified in paragraph (g)(6) of this 
section,'' in Sec.  63.104(g)(4) does not apply.
    (5) Section 63.104(g)(6) and (h)(6) do not apply.
    (6) Beginning no later than the compliance dates specified in Sec.  
63.11494(i), you must not inject water into or dispose of water in the 
heat exchange system if the water is considered wastewater as defined 
in Sec.  63.11502.

0
9. Amend Sec.  63.11500 by revising paragraphs (a)(2) and (b) to read 
as follows:


Sec.  63.11500  What compliance options do I have if part of my plant 
is subject to both this subpart and another Federal standard?

* * * * *
    (a) * * *
    (2) After the compliance dates specified in Sec.  63.11494, at an 
offsite reloading or cleaning facility subject to Sec.  63.1253(f), as 
referenced from Sec.  63.2470(e) and table 5 to this subpart, 
compliance with the monitoring, recordkeeping, and reporting provisions 
of any other subpart of this part constitutes compliance with the 
monitoring, recordkeeping, and reporting provisions of Sec.  
63.1253(f)(7)(ii) or (iii). You must identify in your notification of 
compliance status report required by Sec.  63.11501(b) the subpart of 
this part with which the owner or operator of the offsite reloading or 
cleaning facility complies.
    (b) Compliance with subparts of part 60 of this chapter. If any 
part of a CMPU that is subject to the provisions of this subpart is 
also subject to the provisions of subpart VV, VVa, VVb, DDD, III, IIIa, 
NNN, NNNa, RRR, or RRRa in part 60 of this chapter, then compliance 
with any of the requirements in part 60 of this chapter, subpart VV, 
VVa, VVb, DDD, III, IIIa, NNN, NNNa, RRR, or RRRa that are at least as 
stringent as the corresponding requirements in this subpart constitutes 
compliance with this subpart.
* * * * *

0
10. Amend Sec.  63.11501 by:
0
a. Revising the section heading and paragraph (b) introductory text;
0
b. Adding paragraph (b)(6);
0
c. Revising paragraphs (c) and (d); and
0
d. Removing paragraph (e).
    The revisions and addition read as follows:


Sec.  63.11501  What are the notification, recordkeeping, and reporting 
requirements?

* * * * *
    (b) Notification of compliance status (NOCS). Beginning August 31, 
2026, the owner or operator must submit all subsequent Notification of 
Compliance Status reports in PDF format to the EPA following the 
procedure specified in Sec.  63.9(k). Your NOCS required by Sec.  
63.9(h) must include the following additional information specified in 
paragraphs (b)(1) through (5) of this section, as applicable. Within 
150 days after the first applicable compliance date, you must also 
submit the information in paragraph (b)(6) of this section for 
equipment subject to the requirements of Sec.  63.11495(a)(6).
* * * * *
    (6) For equipment subject to the requirements of Sec.  
63.11495(a)(6), you must also submit the information specified in 
paragraphs (b)(6)(i) through (iv) of this section.
    (i) CMPU identification,
    (ii) Number of each equipment type (e.g., valves, pumps) excluding 
equipment in vacuum service; and
    (iii) Method of compliance with the standard (e.g., ``annual leak 
detection and repair'' or ``equipped with dual mechanical seals'').
    (iv) For pressure relief devices subject to the pressure release 
management work practice standards in Sec.  63.165(e), you must submit 
the information listed in paragraphs (b)(6)(iv)(A) and (B) of this 
section.
    (A) A description of the monitoring system to be implemented, 
including the relief devices and process parameters to be monitored, 
and a description of the alarms or other methods by which operators 
will be notified of a pressure release.
    (B) A description of the prevention measures to be implemented for 
each affected pressure relief device.
    (c) Recordkeeping. You must maintain files of all information 
required by this subpart for at least 5 years following the date of 
each occurrence according to the requirements in Sec.  63.10(b)(1). If 
you are subject, you must comply with the recordkeeping and reporting 
requirements of Sec.  63.10(b)(2)(iii) and (vi) through (xiv), and the 
applicable requirements specified in paragraphs (c)(1) through (11) of 
this section.
    (1) For each CMPU subject to this subpart, you must keep the 
records specified in paragraphs (c)(1)(i) through (viii) of this 
section.
    (i) Except as specified in paragraph (c)(9) of this section, 
records of management practice inspections,

[[Page 16529]]

repairs, and reasons for any delay of repair, as specified in Sec.  
63.11495(a)(5).
    (ii) Except as specified in paragraph (c)(11) of this section, 
records of small heat exchange system inspections, demonstrations of 
indications of leaks that do not constitute leaks, repairs, and reasons 
for any delay in repair as specified in Sec.  63.11495(b).
    (iii) If batch process vent emissions are less than 10,000 lb/yr 
for a CMPU, records of batch process vent emission calculations, as 
specified in Sec.  63.11496(a)(1), the number of batches operated each 
month, as specified in Sec.  63.11496(a)(3), and any updated emissions 
calculations, as specified in Sec.  63.11496(a)(3). Alternatively, keep 
records of the worst-case processes or organic HAP usage, as specified 
in Sec.  63.11496(a)(2) and (4), respectively.
    (iv) Records of all TRE calculations for continuous process vents 
as specified in Sec.  63.11496(b)(2).
    (v) Records of metal HAP emission calculations as specified in 
Sec.  63.11496(f)(1) and (2). If total uncontrolled metal HAP process 
vent emissions from a CMPU subject to this subpart are estimated to be 
less than 400 lb/yr, also keep records of either the number of batches 
per month or operating hours, as specified in Sec.  63.11496(f)(2).
    (vi) Records identifying wastewater streams and the type of 
treatment they receive, as specified in table 6 to this subpart.
    (vii) Before April 1, 2029, records of the date, time, and duration 
of each malfunction of operation of process equipment, control devices, 
recovery devices, or continuous monitoring systems used to comply with 
this subpart that causes a failure to meet a standard. The record must 
include a list of the affected sources or equipment, an estimate of the 
volume of each regulated pollutant emitted over the standard, and a 
description of the method used to estimate the emissions. After April 
1, 2029, for any deviation, records of the start date, start time, 
duration in hours, cause, a list of the affected sources or equipment, 
an estimate of the quantity of each regulated pollutant emitted over 
any emission limit, and a description of the method used to estimate 
the emissions.
    (viii) Before April 1, 2029, records of actions taken during 
periods of malfunction to minimize emissions in accordance with Sec.  
63.11495(d), including corrective actions to restore malfunctioning 
process and air pollution control and monitoring equipment to its 
normal or usual manner of operation. After April 1, 2029, for any 
deviation, records of actions taken to minimize emissions in accordance 
with Sec.  63.11495(d), and any corrective action taken to return the 
affected unit to its normal or usual manner of operation.
    (2) For batch process vents subject to table 2 to this subpart and 
continuous process vents subject to table 3 to this subpart, you must 
keep records specified in paragraphs (c)(2)(i) or (ii) of this section, 
as applicable.
    (i) If you route emissions to a control device other than a flare, 
keep records of performance tests, if applicable, as specified in Sec.  
63.998(a)(2)(ii) and (4), keep records of the monitoring system and the 
monitored parameters, as specified in Sec.  63.998(b) and (c), and keep 
records of the closed-vent system, as specified in Sec.  63.998(d)(1). 
If you use a recovery device to maintain the TRE above 1.0 for a 
continuous process vent, keep records of monitoring parameters during 
the TRE index value determination, as specified in Sec.  63.998(a)(3).
    (ii) If you route emissions to a flare, keep records of the flare 
compliance assessment, as specified in Sec.  63.998(a)(1)(i), keep 
records of the pilot flame monitoring, as specified in Sec.  
63.998(a)(1)(ii) and (iii), and keep records of the closed-vent system, 
as specified in Sec.  63.998(d)(1).
    (3) For metal HAP process vents subject to table 4 to this subpart, 
you must keep records specified in paragraph (c)(3)(i) or (ii) of this 
section, as applicable.
    (i) For a new source using a control device other than a baghouse 
and for any existing source, maintain a monitoring plan, as specified 
in Sec.  63.11496(f)(3)(i), and keep records of monitoring results, as 
specified in Sec.  63.11496(f)(3).
    (ii) For a new source using a baghouse to control metal HAP 
emissions, keep a site-specific monitoring plan, as specified in 
Sec. Sec.  63.11496(f)(4) and 63.11410(g), and keep records of bag leak 
detection systems, as specified in Sec. Sec.  63.11496(f)(4) and 
63.11410(g)(4).
    (4) For each storage tank subject to table 5 to this subpart, you 
must keep records specified in paragraphs (c)(4)(i) through (vii) of 
this section, as applicable.
    (i) Keep records of the vessel dimensions, capacity, and liquid 
stored, as specified in Sec.  63.1065(a).
    (ii) Keep records of each inspection of an internal floating roof, 
as specified in Sec.  63.1065(b)(1).
    (iii) Keep records of each seal gap measurement for external 
floating roofs, as specified in Sec.  63.1065(b)(2), and keep records 
of inspections of external floating roofs, as specified in Sec.  
63.1065(b)(1).
    (iv) If you vent emissions to a control device other than a flare, 
keep records of the operating plan and measured parameter values, as 
specified in Sec. Sec.  63.985(c) and 63.998(d)(2).
    (v) If you vent emissions to a flare, keep records of all periods 
of operation during which the flare pilot flame is absent, as specified 
in Sec. Sec.  63.987(c) and 63.998(a)(1), and keep records of closed-
vent systems, as specified in Sec.  63.998(d)(1).
    (vi) For periods of planned routine maintenance of a control 
device, keep records of the day and time at which each maintenance 
period begins and ends, and keep records of the type of maintenance 
performed, as specified in Sec.  63.11497(b)(3).
    (vii) For each pressure vessel subject to the requirements of Sec.  
63.11497(f) you must keep records as specified in paragraphs 
(c)(4)(vii)(A) and (B) of this section.
    (A) The date of each performance test conducted according to Sec.  
63.11497(f)(2).
    (B) The record of each performance test conducted according to 
Sec.  63.11497(f)(2), including the following:
    (1) Date each defect was detected and the instrument reading (in 
ppmv) during the performance test.
    (2) Date of the next performance test that shows the instrument 
reading is less than 500 ppmv and the instrument reading (in ppmv) 
during the performance test.
    (3) Start and end dates of each period after the date in paragraph 
(c)(4)(ix)(B)(1) of this section when the pressure vessel was 
completely empty.
    (4) Estimated emissions from each defect.
    (5) For each wastewater stream subject to item 2 in table 6 to this 
subpart, keep records of the wastewater stream identification and the 
disposition of the organic phase(s), as specified in item 2 to table 6 
to this subpart.
    (6) Except as specified in paragraph (c)(11) of this section, for 
each large heat exchange system subject to table 8 to this subpart, you 
must keep records of detected leaks; the date the leak was detected; if 
demonstrated not to be a leak, the basis for that determination; the 
date of efforts to repair the leak; and the date the leak is repaired, 
as specified in table 8 to this subpart.
    (7) You must keep a record of all transferred liquids that are 
reactive or resinous materials, as defined in Sec.  63.11502(b), and 
not included in the NOCS.

[[Page 16530]]

    (8) For continuous process vents subject to table 3 to this 
subpart, keep records of the occurrence and duration of each startup 
and shutdown of operation of process equipment, or of air pollution 
control and monitoring equipment.
    (9) If you are subject to the equipment leak requirements specified 
in Sec.  63.11495(a)(6), then you must keep records as specified in 
paragraphs (c)(9)(i) through (vii) of this section instead of the 
records specified in paragraph (c)(1)(i) of this section.
    (i) Keep a list, summary description, or diagram(s) showing the 
location and identification number of all equipment in organic HAP 
service at the facility and the information in paragraphs (c)(9)(i)(A) 
through (D) of this section.
    (A) Identification of equipment designated as unsafe to monitor, 
difficult to monitor, unsafe to inspect, difficult to inspect, or 
unsafe to repair and the plan for monitoring or inspecting this 
equipment, as applicable.
    (B) Identification of the equipment in batch process units, for 
which you do not elect to pressure test the batch product process 
equipment train.
    (C) Identification of the equipment in heavy liquid service.
    (D) Identification of the equipment in organic HAP service less 
than 300 hours per calendar year.
    (ii) For leak detection monitoring and inspections required by 
paragraphs Sec.  63.11495(a)(6) (e.g., monitoring using Method 21 of 
appendix A-7 to part 60 of this chapter; visible, audible, or olfactory 
monitoring; closed vent system inspections; and batch process unit 
monitoring), record the date of the monitoring or inspection and 
include a statement of whether leaks were detected. If no leaks are 
detected, records of the monitoring and inspection results are not 
required.
    (iii) When each leak is detected as specified in Sec.  
63.11495(a)(6), the following information must be recorded:
    (A) The instrument and the equipment identification number and the 
operator name, initials, or identification number.
    (B) The date the leak was detected and the date of first attempt to 
repair the leak.
    (C) The date of successful repair of the leak.
    (D) Maximum instrument reading measured by Method 21 of 40 CFR part 
60, appendix A-7 of this chapter after it is successfully repaired or 
determined to be nonrepairable.
    (E) ``Repair delayed'' and the reason for the delay if a leak is 
not repaired within 15 calendar days after discovery of the leak.
    (1) You may develop a written procedure that identifies the 
conditions that justify a delay of repair. In such cases, reasons for 
delay of repair may be documented by citing the relevant sections of 
the written procedure.
    (2) If delay of repair was caused by depletion of stocked parts, 
there must be documentation that the spare parts were sufficiently 
stocked on-site before depletion and the reason for depletion.
    (F) Dates of CMPU shutdowns that occur while the equipment is 
unrepaired.
    (iv) For each pressure relief device subject to the provisions in 
Sec.  63.165(e), you must keep the records specified in paragraphs 
(c)(9)(iv)(A) through (C) of this section.
    (A) Records of the prevention measures implemented as required in 
Sec.  63.165(e)(3)(ii).
    (B) Records of the number of releases during each calendar year.
    (C) For each release to the atmosphere, you must keep the records 
specified in paragraphs (c)(9)(iv)(C)(1) through (4) of this section.
    (1) The start and end time and date of each pressure release to the 
atmosphere.
    (2) Records of any data, assumptions, and calculations used to 
estimate of the mass quantity of each organic HAP released during the 
event.
    (3) Records of the root cause analysis and corrective action 
analysis conducted as required in Sec.  63.165(e)(3)(iii), including an 
identification of the affected facility, a statement noting whether the 
event resulted from the same root cause(s) identified in a previous 
analysis and either a description of the recommended corrective 
action(s) or an explanation of why corrective action is not necessary 
under Sec.  63.165(e)(7)(i).
    (4) For any corrective action analysis for which implementation of 
corrective actions are required in Sec.  63.165(e)(7), a description of 
the corrective action(s) completed within the first 45 days following 
the discharge and, for action(s) not already completed, a schedule for 
implementation, including proposed commencement and completion dates.
    (v) If you own or operate a batch product process and elect to 
pressure test the batch product process equipment train to demonstrate 
compliance with Sec.  63.11495(a)(6), you are exempt from the 
requirements of paragraphs (c)(9)(i) through (iv) of this section. 
Instead, you must maintain records of the following information:
    (A) A list of identification numbers for equipment in a batch 
product process.
    (B) The dates of each pressure test required in Sec.  63.178(b), 
the test pressure, and the pressure drop observed during the test.
    (C) When a batch product process equipment train does not pass two 
consecutive pressure tests, the following information must be recorded:
    (1) The date of each pressure test and the date of each leak repair 
attempt.
    (2) Repair methods applied in each attempt to repair the leak.
    (3) The reason for the delay of repair.
    (4) The expected date for delivery of the replacement equipment and 
the actual date of delivery of the replacement equipment.
    (5) The date of successful repair.
    (vi) You must maintain records of the information specified in 
paragraphs (c)(9)(vi)(A) through (C) of this section for closed vent 
systems and control devices subject to the provisions of Sec.  63.172. 
The records specified in paragraph (c)(9)(vi)(A) of this section must 
be retained for the life of the equipment.
    (A) The design specifications and performance demonstrations 
specified in paragraphs (c)(9)(vi)(A)(1) through (4) of this section.
    (1) Detailed schematics, design specifications of the control 
device, and piping and instrumentation diagrams.
    (2) The dates and descriptions of any changes in the design 
specifications.
    (3) The flare design (i.e., steam-assisted, air-assisted, or non-
assisted) and the results of the compliance demonstration required by 
subpart SS of this part.
    (4) A description of the parameter or parameters monitored, as 
required in Sec.  63.172(e), to ensure that control devices are 
operated and maintained in conformance with their design and an 
explanation of why that parameter (or parameters) was selected for the 
monitoring.
    (B) Records of operation of closed vent systems and control 
devices, as specified in paragraphs (c)(9)(vi)(B)(1) through (3) of 
this section.
    (1) Dates and durations when the closed vent systems and control 
devices required in Sec.  63.11495(a)(6) are not operated as designed 
as indicated by the monitored parameters, including periods when a 
flare pilot light system does not have a flame.
    (2) Dates and durations during which the monitoring system or 
monitoring device is inoperative.
    (3) Dates and durations of startups and shutdowns of control 
devices required in Sec.  63.11495(a)(6).

[[Page 16531]]

    (C) Records of inspections of closed vent systems subject to the 
provisions of Sec.  63.172, as specified in paragraphs (c)(9)(vi)(C)(1) 
and (2) of this section.
    (1) For each inspection conducted in accordance with the provisions 
of Sec.  63.172(f)(1) or (2) during which leaks were detected, the 
information specified in paragraph (c)(9)(iii) of this section must be 
recorded.
    (2) For each flow event from a bypass line subject to the 
requirements in Sec.  63.172(j), you must maintain records sufficient 
to determine whether or not the detected flow included flow requiring 
control. For each flow event from a bypass line requiring control that 
is released either directly to the atmosphere or to a control device 
not meeting the requirements in Sec.  63.11495(a)(6), you must include 
an estimate of the volume of gas, the concentration of organic HAP in 
the gas, and the resulting emissions of organic HAP that bypassed the 
control device using process knowledge and engineering estimates.
    (vii) If you choose to comply with the requirements of Sec.  
63.179, you must maintain the following records:
    (A) Identification of the CMPU(s) and the organic HAPs they handle.
    (B) A schematic of the CMPU, enclosure, and closed vent system.
    (C) A description of the system used to create a negative pressure 
in the enclosure to ensure that all emissions are routed to the control 
device.
    (10) For each flow event from a bypass line subject to the 
requirements in Sec.  63.11495(e), you must maintain records sufficient 
to determine whether or not the detected flow included flow requiring 
control. For each flow event from a bypass line requiring control that 
is released either directly to the atmosphere or to a control device 
not meeting the requirements specified in Sec. Sec.  63.11495 through 
63.11499, you must include an estimate of the volume of gas, the 
concentration of organic HAP in the gas and the resulting emissions of 
organic HAP that bypassed the control device using process knowledge 
and engineering estimates.
    (11) If you are subject to the requirements specified in item 1.c 
of table 8 to this subpart (for heat exchange systems with a cooling 
water flow rate greater than or equal to 8,000 gal/min), then you must 
keep records as specified in Sec.  63.104(f)(3) instead of the heat 
exchange system records specified in paragraphs (c)(1)(ii) and (6) of 
this section.
    (d) Semiannual compliance reports. You must submit semiannual 
compliance reports that contain the information specified in paragraphs 
(d)(1) through (12) of this section, as applicable. All reports must 
contain the company name and address (including county), as well as the 
beginning and ending dates of the reporting period. For periods where 
no events described by paragraphs (d)(1) through (12) of this section 
occur, a statement must be included in the report pursuant to Sec.  
63.10(e)(3)(v). Beginning on April 1, 2029, or once the report template 
for this subpart has been available on the CEDRI website for one year, 
whichever date is later, submit all subsequent reports using the 
appropriate electronic report template on the CEDRI website (https://www.epa.gov/electronic-reporting-air-emissions/cedri) for this subpart 
and following the procedure specified in Sec.  63.9(k). The date report 
templates become available will be listed on the CEDRI website. Unless 
the Administrator or delegated State agency or other authority has 
approved a different schedule for submission of reports, the report 
must be submitted by the deadline specified in this subpart, regardless 
of the method in which the report is submitted.
    (1) Deviations. Before April 1, 2029 you must clearly identify any 
deviation from the requirements of this subpart. Beginning on April 1, 
2029, for each deviation, you must report the start date, start time, 
duration in hours, cause, a list of the affected sources or equipment, 
an estimate of the quantity of each regulated pollutant emitted over 
any emission limit, a description of the method used to estimate the 
emissions, actions taken to minimize emissions, and any corrective 
action taken to return the affected unit to its normal or usual manner 
of operation.
    (2) Delay of repair for a large heat exchange system. Except as 
specified in paragraph (d)(11) of this section, you must include the 
information specified in Sec.  63.104(f)(2) each time you invoke the 
delay of repair provisions for a heat exchange system with a cooling 
water flow rate equal to or greater than 8,000 gal/min.
    (3) Delay of leak repair. You must provide the following 
information for each delay of leak repair beyond 15 days for any 
process equipment, storage tank, surge control vessel, bottoms 
receiver, and each delay of leak repair beyond 45 days for any heat 
exchange system with a cooling water flow rate less than 8,000 gal/min: 
information on the date the leak was identified, the reason for the 
delay in repair, and the date the leak was repaired.
    (4) Process change. You must report each process change that 
affects a compliance determination and submit a new certification of 
compliance with the applicable requirements in accordance with the 
procedures specified in paragraph (b) of this section.
    (5) Data for the alternative standard. If you comply with the 
alternative standard, as specified in table 2 or 3 to this subpart, 
report the information required in Sec.  63.1258(b)(5).
    (6) Overlapping rule requirements. Report any changes in the 
overlapping provisions with which you comply.
    (7) Reactive and resinous materials. Report any transfer of liquids 
that are reactive or resinous materials, as defined in Sec.  
63.11502(b), and not included in the NOCS.
    (8) Malfunctions. If a malfunction occurred during the reporting 
period, the report must include the number of instances of malfunctions 
that caused emissions in excess of a standard. For each malfunction 
that caused emissions in excess of a standard, the report must include 
a list of the affected sources or equipment, an estimate of the volume 
of each regulated pollutant emitted over the standard, and a 
description of the method used to estimate the emissions. The report 
must also include a description of actions you took during a 
malfunction of an affected source to minimize emissions in accordance 
with Sec.  63.11495(d), including actions taken to correct a 
malfunction. On and after April 1, 2029, malfunctions are reported as 
deviations under paragraph (d)(1) of this section and this paragraph 
(d)(8) no longer applies.
    (9) Equipment leaks. For each CMPU complying with the provisions of 
Sec.  63.11495(a)(6), report the information listed in paragraphs 
(d)(9)(i) through (vi) of this section.
    (i) The number of components for which leaks were detected, the 
total number of components monitored, and the number of components for 
which leaks were not repaired, identifying the number of those that are 
determined nonrepairable, and totaled by component type.
    (ii) The facts that explain any delay of repairs and, where 
appropriate, why a CMPU shutdown was technically infeasible.
    (iii) For pressure relief devices subject to the requirements in 
Sec.  63.11495(a)(6)(iv) include the information specified in 
paragraphs (d)(9)(iii)(A) through (C) of this section.
    (A) For pressure relief devices in organic HAP gas or vapor 
service, pursuant to Sec.  63.165(e)(1), report the instrument readings 
and dates for all readings of 500 ppm or greater.
    (B) For pressure relief devices in organic HAP gas or vapor 
service, pursuant to Sec.  63.165(e)(2), report the

[[Page 16532]]

instrument readings and dates of instrument reading conducted.
    (C) For pressure relief devices in organic HAP service subject to 
Sec.  63.165(e)(3), report each pressure release to the atmosphere, 
including pressure relief device identification name or number, the 
start date, start time, and duration (in minutes) of the pressure 
release; an estimate of the mass quantity in pounds of each organic HAP 
released; the results of any root cause analysis and corrective action 
analysis completed during the reporting period, including the 
corrective actions implemented during the reporting period; and, if 
applicable, the implementation schedule for planned corrective actions 
to be implemented subsequent to the reporting period.
    (iv) For bypass lines subject to the requirements in Sec.  
63.172(j) as specified in Sec.  63.11495(a)(6)(ix), include the start 
date, start time, duration in hours, estimate of the volume of gas in 
standard cubic feet, the concentration of organic HAP in the gas in 
parts per million by volume and the resulting mass emissions of organic 
HAP in pounds that bypass a control device. For periods when the flow 
indicator is not operating, report the start date, start time, and 
duration in hours.
    (v) If applicable, the compliance option selected under Sec.  
63.172(n) as specified in Sec.  63.11495(a)(6)(ix).
    (vi) If you elect to meet the requirements in Sec.  63.178(b) as 
specified in Sec.  63.11495(a)(6)(xi), include the information listed 
in paragraphs (d)(9)(vi)(A) through (E) of this section.
    (A) Batch product process equipment train identification;
    (B) The number of pressure tests conducted;
    (C) The number of pressure tests where the equipment train failed 
the pressure test;
    (D) The facts that explain any delay of repairs; and
    (E) The results of all monitoring to determine compliance with 
Sec.  63.172(f).
    (10) Bypass lines. For bypass lines subject to the requirements 
Sec.  63.11495(e), report the start date, start time, duration in 
hours, estimate of the volume of gas in standard cubic feet, the 
concentration of organic HAP in the gas in ppmv and the resulting mass 
emissions of organic HAP in pounds that bypass a control device. For 
periods when the flow indicator is not operating, report the start 
date, start time, and duration in hours.
    (11) Heat exchange systems. If you are subject to the requirements 
specified in item 1.c of table 8 to this subpart (for heat exchange 
systems with a cooling water flow rate greater than or equal to 8,000 
gal/min), then you must submit the information specified in Sec.  
63.104(f)(2)(vi) instead of the heat exchange system information 
specified in paragraphs (d)(2) and (3) of this section.
    (12) Pressure vessels. If you are subject to the requirements 
specified in Sec.  63.11497(e) and obtain an instrument reading greater 
than 500 ppmv when monitoring a pressure vessel in accordance with 
Sec.  63.11497(e)(2), report an identification of the pressure vessel 
and a copy of the records specified in paragraph (c)(4)(vii)(B) of this 
section.

0
11. Amend Sec.  63.11502 by:
0
a. Revising paragraph (a) and paragraph (b) introductory text; and
0
b. In paragraph (b):
0
i. Removing the definition of ``Affirmative defense'';
0
ii. Revising the definitions of ``Continuous process vent'' and ``In 
organic HAP service'';
0
iii. Adding the definition of ``Inaccessible connector'' in 
alphabetical order; and
0
iv. Revising the definitions of ``Metal HAP process vent'', ``Point of 
determination'', ``Process vessel'', ``Storage tank'', and 
``Wastewater''.
    The revisions and additions read as follows:


Sec.  63.11502  What definitions apply to this subpart?

    (a) The following terms used in this subpart have the meaning given 
them in the CAA, and in subparts A, F, SS, WW, and FFFF of this part, 
as specified after each term:

                        Table 1 to Paragraph (a)
------------------------------------------------------------------------
                             Term                                40 CFR
------------------------------------------------------------------------
Administrator.................................................      63.2
Area Source...................................................      63.2
Article.......................................................     372.3
Batch operation...............................................   63.2550
Boiler........................................................    63.101
Bottoms receiver..............................................   63.2550
CAA...........................................................      63.2
Closed vent system............................................    63.981
Combustion device.............................................    63.101
Commenced.....................................................      63.2
Compliance date...............................................      63.2
Continuous monitoring system..................................      63.2
Continuous operation..........................................   63.2550
Control device................................................    63.101
Distillation unit.............................................    63.101
Emission standard.............................................      63.2
EPA...........................................................      63.2
Fill or filling...............................................    63.101
Floating roof.................................................   63.1061
Fuel gas system...............................................    63.981
Halogen atoms.................................................   63.2550
Halogenated vent stream.......................................   63.2550
Hydrogen halide and halogen HAP...............................   63.2550
Hazardous air pollutant.......................................      63.2
Heat exchange system..........................................    63.101
Incinerator...................................................    63.101
In gas/vapor service..........................................    63.101
In heavy liquid service.......................................    63.101
In light liquid service.......................................    63.101
In liquid service.............................................    63.101
Isolated intermediate.........................................   63.2550
Maintenance wastewater........................................   63.2550
Major source..................................................      63.2
Maximum true vapor pressure...................................    63.101
Oil-water separator or organic-water separator................    63.101
Operating permit..............................................    63.101
Owner or operator.............................................      63.2
Performance test..............................................      63.2
Pressure release..............................................    63.101
Pressure relief device or valve...............................    63.101
Pressure vessel...............................................    63.101
Process condenser.............................................   63.2550
Process heater................................................    63.101
Process tank..................................................   63.2550
Process wastewater............................................    63.101
Reactor.......................................................    63.101
Responsible official..........................................      63.2
State.........................................................      63.2
Supplemental gases............................................   63.2550
Surge control vessel..........................................   63.2550
Test method...................................................      63.2
Unit operation................................................    63.101
------------------------------------------------------------------------

    (b) All other terms used in this subpart shall have the meaning 
given them in this section. If a term is defined in the CAA, or in 
subpart A, F, SS, WW, or FFFF of this part, and in this section, the 
term has the meaning given in this section for purposes of this 
subpart.
* * * * *
    Continuous process vent means a ``process vent'' as defined in 
Sec.  63.101 except:
    (i) The reference in Sec.  63.107(e) to a chemical manufacturing 
process unit that meets the criteria of Sec.  63.100(b) means a CMPU 
that meets the criteria of Sec.  63.11494(a) and (b);
    (ii) The reference in Sec.  63.107(h)(2) to subpart H means Sec.  
63.11495(a)(3) through (6) for the purposes of this subpart;
    (iii) The reference in Sec.  63.107(h)(4) to Sec.  63.113 means 
tables 2 and 3 to this subpart;
    (iv) The reference in Sec.  63.107(h)(7) to Sec.  63.119 means 
Table 5 to this subpart, and the reference to Sec.  63.126 does not 
apply for the purposes of this subpart;
    (v) The second sentence in the definition of ``process vent'' in 
Sec.  63.101 does not apply for the purposes of this subpart;
    (vi) The references to an ``air oxidation reactor, distillation 
unit, or reactor'' in Sec.  63.107 means any continuous operation for 
the purposes of this subpart;
    (vii) Section Sec.  63.107(h)(8) does not apply for the purposes of 
this subpart; and
    (viii) A separate determination is required for the emissions from 
each CMPU, even if emission streams from two or more CMPU are combined 
prior

[[Page 16533]]

to discharge to the atmosphere or to a control device.
    (ix) On and after April 1, 2029, Sec.  63.107(h)(9) no longer 
applies.
    (1x) On and after April 1, 2028, Sec.  63.107(i) no longer applies. 
Instead, a process vent is the point of discharge to the atmosphere (or 
the point of entry into a control device, if any) of a gas stream if 
the gas stream would meet the characteristics specified in Sec.  
63.107(b) through (g), but, for purposes of avoiding applicability, has 
been deliberately interrupted, temporarily liquefied, routed through 
any item of equipment for no process purpose, or disposed of in a 
control device that does not meet the criteria in table 3 of this 
subpart.
* * * * *
    In organic HAP service means, before April 1, 2029, that a process 
vessel or piece of equipment either contains or contacts a feedstock, 
byproduct, or product that contains an organic HAP, excluding any 
organic HAP used in manual cleaning activities. A process vessel is no 
longer in organic HAP service after the vessel has been emptied to the 
extent practicable (i.e., a vessel with liquid left on process vessel 
walls or as bottom clingage, but not in pools, due to floor 
irregularity, is considered completely empty) and any cleaning has been 
completed. On and after April 1, 2029, In organic HAP service, for a 
process vessel, means either contains or contacts a feedstock, 
byproduct, or product that contains an organic HAP, excluding any 
organic HAP used in manual cleaning activities. A process vessel is no 
longer in organic HAP service after the vessel has been emptied to the 
extent practicable (i.e., a vessel with liquid left on process vessel 
walls or as bottom clingage, but not in pools, due to floor 
irregularity, is considered completely empty) and any cleaning has been 
completed. On and after April 1, 2029, In organic HAP service, for 
equipment and heat exchange systems, means that a piece of equipment or 
heat exchange system either contains or contacts a fluid (liquid or 
gas) that is at least 5 percent by weight of total organic HAPs as 
determined according to the provisions of Sec.  63.180(d). The 
provisions of Sec.  63.180(d) also specify how to determine that a 
piece of equipment is not in organic HAP service. For purposes of the 
definition of ``heat exchange system'' in Sec.  63.101(b), the term 
``equipment'' in Sec.  63.180(d) includes heat exchange systems.
* * * * *
    Inaccessible connector means a connector that is:
    (i) Buried;
    (ii) Insulated in a manner that prevents access to the connector by 
a monitor probe;
    (iii) Obstructed by equipment or piping that prevents access to the 
connector by a monitor probe;
    (iv) Unable to be reached from a wheeled scissor-lift or hydraulic-
type scaffold which would allow access to connectors up to 7.6 meters 
(25 feet) above the ground;
    (v) Inaccessible because it would require elevating the monitoring 
personnel more than 2 meters above a permanent support surface or would 
require the erection of scaffold; or
    (vi) Not able to be accessed at any time in a safe manner to 
perform monitoring. Unsafe access includes, but is not limited to, the 
use of a wheeled scissor-lift on unstable or uneven terrain, the use of 
a motorized man-lift basket in areas where an ignition potential 
exists, or access would require near proximity to hazards such as 
electrical lines, or would risk damage to equipment.
* * * * *
    Metal HAP process vent means, before April 1, 2029, the point of 
discharge to the atmosphere (or inlet to a control device, if any) of a 
metal HAP-containing gas stream from any CMPU at an affected source 
containing at least 50 ppmv metal HAP. The metal HAP concentration may 
be determined using any of the following: process knowledge, an 
engineering assessment, or test data. On and after April 1, 2029, Metal 
HAP process vent means the point of discharge to the atmosphere (or 
inlet to a control device, if any) of a metal HAP-containing gas stream 
from any CMPU at an affected source containing metal HAP. The metal HAP 
concentration may be determined using any of the following: process 
knowledge, an engineering assessment, or test data.
* * * * *
    Point of determination means ``point of determination'' as defined 
in Sec.  63.101, except:
    (i) The reference to table 8 or 9 compounds means table 9 to 
subpart G of this part or table 7 to this subpart compounds;
    (ii) The reference to ``as determined in Sec.  63.144'' does not 
apply for the purposes of this subpart; and
    (iii) The point of determination is made at the point where the 
stream exits the CMPU. If a recovery device is used, the point of 
determination is after the last recovery device.
    Process vessel means each vessel, except hand-held containers, used 
in the processing of raw materials to chemical products. Examples 
include, but are not limited to centrifuges, mixing vessels, and 
process tanks.
* * * * *
    Storage tank means a tank or other vessel that is used to store 
liquids that contain organic HAP and that are part of a CMPU subject to 
this subpart VVVVVV. The following are not considered storage tanks for 
the purposes of this subpart:
    (i) Vessels permanently attached to motor vehicles such as trucks, 
railcars, barges, or ships;
    (ii) [Reserved]
    (iii) Process tanks;
    (iv) Tanks storing organic liquids containing HAP only as 
impurities;
    (v) Surge control vessels;
    (vi) Bottoms receivers; and
    (vii) Wastewater storage tanks.
* * * * *
    Wastewater means water that is discarded from a CMPU or control 
device and that contains at least 5 ppmw of any HAP listed in table 9 
to subpart G of this part and has an annual average flow rate of 0.02 
liters per minute. Wastewater means both process wastewater and 
maintenance wastewater that is discarded from a CMPU or control device. 
The following are not considered wastewater for the purposes of this 
subpart:
    (i) Stormwater from segregated sewers;
    (ii) Water from fire-fighting and deluge systems, including testing 
of such systems;
    (iii) Spills;
    (iv) Water from safety showers;
    (v) Samples of a size not greater than reasonably necessary for the 
method of analysis that is used;
    (vi) Equipment leaks;
    (vii) Wastewater drips from procedures such as disconnecting hoses 
after cleaning lines; and
    (viii) Noncontact cooling water.
* * * * *

0
12. Amend Sec.  63.11503 by revising paragraph (b) introductory text 
and adding paragraph (b)(5) to read as follows:


Sec.  63.11503  Who implements and enforces this subpart?

* * * * *
    (b) In delegating implementation and enforcement authority of this 
subpart to a State, local, or Tribal agency under subpart E of this 
part, the approval authorities contained in paragraphs (b)(1) through 
(5) of this section are retained by the Administrator of the U.S. EPA 
and are not transferred to the state, local, or Tribal agency.
* * * * *

[[Page 16534]]

    (5) Approval of an alternative to any electronic reporting to the 
EPA required by this subpart.

0
13. Amend table 3 to subpart VVVVVV of part 63 by revising entry ``1. 
Each continuous process vent with a TRE <=1.0'' to read as follows:
* * * * *

 Table 3 to Subpart VVVVVV of Part 63--Emission Limits and Compliance Requirements for Continuous Process Vents
                                                    * * * * *
----------------------------------------------------------------------------------------------------------------
             For . . .                                You must . . .                         Except . . .
----------------------------------------------------------------------------------------------------------------
1. Each continuous process vent      a. Reduce emissions of total organic HAP by      i. Compliance may be based
 with a TRE <=1.0.                    >=95 percent by weight (>=85 percent by weight   on either total organic
                                      for periods of startup or shutdown) or to <=20   HAP or TOC; and
                                      ppmv by routing emissions through a closed      ii. As specified in Sec.
                                      vent system to any combination of control        63.11496(g).
                                      devices (except a flare) in accordance with
                                      the requirements of Sec.   63.982(c) and the
                                      requirements referenced therein; or
                                     b. Reduce emissions of total organic HAP by      i. Not applicable.
                                      routing all emissions through a closed-vent
                                      system to a flare (except that a flare may not
                                      be used to control halogenated vent streams)
                                      in accordance with the requirements of Sec.
                                      63.982(b) and the requirements referenced
                                      therein, or
                                     c. Comply with the alternative standard          i. As specified in Sec.
                                      specified in Sec.   63.2505 and the              63.11496(e).
                                      requirements referenced therein.
 
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------


0
14. Revise table 4 to subpart VVVVVV of part 63 to read as follows:

  Table 4 to Subpart VVVVVV of Part 63--Emission Limits and Compliance Requirements for Metal HAP Process Vents
 [As required in Sec.   63.11496(f), you must comply with the requirements for metal HAP process vents as shown
                                            in the following table.]
----------------------------------------------------------------------------------------------------------------
              For * * *                                 You must * * *                         Except * * *
----------------------------------------------------------------------------------------------------------------
Each CMPU with total metal HAP         Reduce collective uncontrolled emissions of       Not applicable.
 emissions >=400 lb/yr.                 total metal HAP emissions by >=95 percent by
                                        weight by routing emissions from a sufficient
                                        number of the metal HAP process vents through a
                                        closed vent system to any combination of
                                        control devices, according to the requirements
                                        of Sec.   63.11496(f)(3), (4), or (5).
----------------------------------------------------------------------------------------------------------------


0
15. Amend table 5 to subpart VVVVVV of part 63 by:
0
a. Revising the entry ``1. Storage tank with a design capacity >=40,000 
gallons, storing liquid that contains organic HAP listed in table 1 to 
this subpart, and for which the maximum true vapor pressure (MTVP) of 
total organic HAP at the storage temperature is >=5.2 kPa and <76.6 
kPa.''; and
0
b. Adding the entry ``5. Pressure vessel with a design capacity greater 
than or equal to 20,000 gallons'' in numerical order.
    The revision and addition read as follows:
* * * * *

  Table 5 to Subpart VVVVVV of Part 63--Emission Limits and Compliance
                     Requirements for Storage Tanks
                                * * * * *
------------------------------------------------------------------------
       For each * * *            You must * * *         Except * * *
------------------------------------------------------------------------
1. Storage tank with a        a. Comply with the    i. All required
 design capacity >=40,000      requirements of       seals must be
 gallons, storing liquid       subpart WW of this    installed by the
 that contains organic HAP     part;                 compliance date in
 listed in table 1 to this                           Sec.   63.11494.
 subpart, and for which the
 maximum true vapor pressure
 (MTVP) of total organic HAP
 at the storage temperature
 is >=5.2 kPa and <76.6 kPa.
                              b. Reduce total       i. Compliance may be
                               organic HAP           based on either
                               emissions by >=95     total organic HAP
                               percent by weight     or TOC;
                               by operating and     ii. When the term
                               maintaining a         storage vessel is
                               closed-vent system    used in subpart SS
                               and control device    of this part, the
                               (other than a         term storage tank,
                               flare) in             surge control
                               accordance with       vessel, or bottoms
                               Sec.   63.982(c);     receiver, as
                               or                    defined in Sec.
                                                     63.11502 of this
                                                     subpart, applies;
                                                     and
                                                    iii. The
                                                     requirements do not
                                                     apply during
                                                     periods of planned
                                                     routine maintenance
                                                     of the control
                                                     device, as
                                                     specified in Sec.
                                                     63.11497(b).

[[Page 16535]]

 
                              c. Reduce total HAP   i. The requirements
                               emissions by          do not apply during
                               operating and         periods of planned
                               maintaining a         routine maintenance
                               closed-vent system    of the flare, as
                               and a flare in        specified in Sec.
                               accordance with       63.11497(b); and
                               Sec.   63.982(b);    ii. When the term
                               or                    storage vessel is
                                                     used in subpart SS
                                                     of this part, it
                                                     means storage tank,
                                                     surge control
                                                     vessel, or bottoms
                                                     receiver, as
                                                     defined in Sec.
                                                     63.11502 of this
                                                     subpart.
                              d. Vapor balance in   i. To comply with
                               accordance with       Sec.
                               Sec.   63.2470(e);    63.1253(f)(6)(i),
                               or                    the owner or
                                                     operator of an
                                                     offsite cleaning or
                                                     reloading facility
                                                     must comply with
                                                     Sec.   63.11494
                                                     through Sec.
                                                     63.11502 instead of
                                                     complying with Sec.
 
                                                     63.1253(f)(7)(ii),
                                                     except as specified
                                                     in item 1.d.ii and
                                                     1.d.iii of this
                                                     table.
                                                    ii. The reporting
                                                     requirements in
                                                     Sec.   63.11501 do
                                                     not apply to the
                                                     owner or operator
                                                     of the offsite
                                                     cleaning or
                                                     reloading facility.
                                                    iii. As an
                                                     alternative to
                                                     complying with the
                                                     monitoring,
                                                     recordkeeping, and
                                                     reporting
                                                     provisions in Sec.
                                                     Sec.   63.11494
                                                     through 63.11502,
                                                     the owner or
                                                     operator of an
                                                     offsite cleaning or
                                                     reloading facility
                                                     may comply as
                                                     specified in Sec.
                                                     63.11500 with any
                                                     other subpart of
                                                     this part which has
                                                     monitoring,
                                                     recordkeeping, and
                                                     reporting
                                                     provisions as
                                                     specified in Sec.
                                                     63.11500.
                              e. Route emissions    i. When the term
                               to a fuel gas         storage vessel is
                               system or process     used in subpart SS
                               in accordance with    of this part, it
                               the requirements in   means storage tank,
                               Sec.   63.982(d)      surge control
                               and the               vessel, or bottoms
                               requirements          receiver, as
                               referenced therein    defined in Sec.
                                                     63.11502.
 
                              * * * * * * *
5. Pressure vessel with a     a. Beginning no
 design capacity greater       later than the
 than or equal to 20,000       compliance dates
 gallons.                      specified in Sec.
                               63.11494(i), comply
                               with the
                               requirements
                               specified in Sec.
                               63.11497(e).
------------------------------------------------------------------------


0
16. Revise table 8 to subpart VVVVVV of part 63 to read as follows:

  Table 8 to Subpart VVVVVV of Part 63--Emission Limits and Compliance
                 Requirements for Heat Exchange Systems
 [As required in Sec.   63.11499, you must comply with the requirements
       for heat exchange systems as shown in the following table.]
------------------------------------------------------------------------
          For . . .              You must . . .         Except . . .
------------------------------------------------------------------------
1. Each heat exchange system  a. Except as          i. The reference to
 with a cooling water flow     specified in item     monthly monitoring
 rate >=8,000 gal/min and      1.c of this table,    for the first 6
 not meeting one or more of    comply with the       months in Sec.
 the conditions in Sec.        monitoring            63.104(b)(1) and
 63.104(a)(1) through (4).     requirements in       (c)(1)(iii) does
                               Sec.   63.104(c),     not apply.
                               the leak repair       Monitoring shall be
                               requirements in       no less frequent
                               Sec.   63.104(d)      than quarterly;
                               and (e), and the     ii. The reference in
                               recordkeeping and     Sec.   63.104(f)(1)
                               reporting             to record retention
                               requirements in       requirements in
                               Sec.   63.104(f);     Sec.   63.103(c)(1)
                               or                    does not apply.
                                                     Records must be
                                                     retained as
                                                     specified in Sec.
                                                     Sec.   63.10(b)(1)
                                                     and 63.11501(c);
                                                     and
                                                    iii. The reference
                                                     in Sec.
                                                     63.104(f)(2) to
                                                     ``the next semi-
                                                     annual periodic
                                                     report required by
                                                     Sec.   63.152(c)''
                                                     means the next
                                                     semiannual
                                                     compliance report
                                                     required by Sec.
                                                     63.11501(d).
                              b. Except as          i. Not applicable.
                               specified in item
                               1.c of this table,
                               comply with the
                               heat exchange
                               system requirements
                               in Sec.   63.104(b)
                               and the
                               requirements
                               referenced therein

[[Page 16536]]

 
                              c. Beginning no       i. As specified in
                               later than the        Sec.   63.11499(d).
                               compliance dates
                               specified in Sec.
                               63.11494(i), the
                               exemption
                               conditions
                               specified in Sec.
                               63.104(a)(3) and
                               (4), and items 1.a
                               and 1.b of this
                               table no longer
                               apply. Instead,
                               comply with the
                               requirements in
                               Sec.   63.104(f)
                               through (j) and (l).
------------------------------------------------------------------------


0
17. Revise table 9 to subpart VVVVVV of part 63 to read as follows:

           Table 9 to Subpart VVVVVV of Part 63--Applicability of General Provisions to Subpart VVVVVV
 [As required in Sec.   63.11501(a), you must comply with the requirements of the NESHAP General Provisions (40
                            CFR part 63, subpart A) as shown in the following table.]
----------------------------------------------------------------------------------------------------------------
              Citation                        Subject           Applies to this subpart?        Explanation
----------------------------------------------------------------------------------------------------------------
63.1(a)(1), (a)(2), (a)(3), (a)(4),   Applicability..........  Yes......................
 (a)(6), (a)(10)-(a)(12) (b)(1),
 (b)(3), (c)(1), (c)(2), (c)(5), (e).
63.1(a)(5), (a)(7)-(a)(9), (b)(2),    Reserved...............  No.......................
 (c)(3), (c)(4), (d).
63.2................................  Definitions............  Yes......................
63.3................................  Units and Abbreviations  Yes......................
63.4................................  Prohibited Activities    Yes......................
                                       and Circumvention.
63.5................................  Preconstruction Review   Yes......................
                                       and Notification
                                       Requirements.
63.6(a), (b)(1)-(b)(5), (b)(7),       Compliance with          Yes......................
 (c)(1), (c)(2), (c)(5),               Standards and
 (e)(1)(iii), (g), (i), (j).           Maintenance
                                       Requirements.
63.6(b)(6), (c)(3), (c)(4), (d),      Reserved...............  No.......................
 (e)(2).
63.6(e)(1)(i) and (ii), (e)(3), and   SSM Requirements.......  No.......................  See Sec.   63.11495(d)
 (f)(1).                                                                                   for general duty
                                                                                           requirement. The
                                                                                           standards in this
                                                                                           subpart apply at all
                                                                                           times.
63.6(f).............................  Compliance with          Yes......................
                                       Nonopacity Emission
                                       Standards.
63.6(h).............................  Compliance with Opacity  No.......................  This subpart does not
                                       and Visible Emission                                include opacity or
                                       Standards.                                          visible emissions
                                                                                           (VE) standards or
                                                                                           require a continuous
                                                                                           opacity monitoring
                                                                                           system (COMS).
63.7(a)(1), (a)(3), (a)(4), (c),      Performance Testing      Yes......................  Except this subpart
 (e)(4), and (f)-(h).                  Requirements.                                       specifies how and
                                                                                           when the performance
                                                                                           test results are
                                                                                           reported.
63.7(a)(2), (b), (d), (e)(2)-(e)(3).  Performance Testing      Yes/No...................  Requirements apply if
                                       Schedule, Notification                              conducting test for
                                       of Performance Test,                                metal HAP control;
                                       Performance Testing                                 requirements in Sec.
                                       Facilities, and                                     Sec.   63.997(c)(1),
                                       Conduct of Performance                              (d), (e), and
                                       Tests.                                              63.999(a)(1) apply,
                                                                                           as referenced in Sec.
                                                                                             63.11496(g), if
                                                                                           conducting test for
                                                                                           organic HAP or
                                                                                           hydrogen halide and
                                                                                           halogen HAP control
                                                                                           device.
63.7(e)(1)..........................  Performance Testing....  No.......................  See Sec.
                                                                                           63.11496(f)(3)(ii) if
                                                                                           conducting a test for
                                                                                           metal HAP emissions.
                                                                                           See Sec.  Sec.
                                                                                           63.11496(g) and
                                                                                           63.997(e)(1) if
                                                                                           conducting a test for
                                                                                           continuous process
                                                                                           vents or for hydrogen
                                                                                           halide and halogen
                                                                                           emissions. See Sec.
                                                                                           Sec.   63.11496(g)
                                                                                           and 63.2460(c) if
                                                                                           conducting a test for
                                                                                           batch process vents.
63.8(a)(1), (b), (c)(1)(ii), (c)(2)-  Monitoring Requirements  Yes......................
 (c)(3), (f)(1)-(5).
63.8(a)(2)..........................  Monitoring Requirements  No.......................
63.8(a)(3)..........................  Reserved...............  No.......................
63.8(a)(4)..........................  Monitoring Requirements  Yes......................
63.8(c)(1)(i).......................  General Duty to          No.......................
                                       Minimize Emissions and
                                       CMS Operation.
63.8(c)(1)(iii).....................  Requirement to Develop   No.......................
                                       SSM Plan for CMS.

[[Page 16537]]

 
63.8(c)(4)..........................  .......................  Yes......................  Only for CEMS. CPMS
                                                                                           requirements in
                                                                                           subpart SS of this
                                                                                           part are referenced
                                                                                           from Sec.   63.11496.
                                                                                           Requirements for COMS
                                                                                           do not apply because
                                                                                           this subpart does not
                                                                                           require COMS.
63.8(c)(5)..........................  .......................  No.......................  This subpart does not
                                                                                           require COMS.
63.8(c)(6)-(c)(8), (d)(1)-(d)(2),     .......................  Yes......................  Requirements apply
 (e), (f)(6).                                                                              only if you use a
                                                                                           continuous emission
                                                                                           monitoring system
                                                                                           (CEMS) to demonstrate
                                                                                           compliance with the
                                                                                           alternative standard
                                                                                           in Sec.
                                                                                           63.11496(e).
                                                                                           Additionally, this
                                                                                           subpart specifies how
                                                                                           and when the
                                                                                           performance
                                                                                           evaluation results
                                                                                           are reported.
63.8(d)(3)..........................  Written Procedures for   Yes......................  Requirement applies
                                       CMS.                                                except for last
                                                                                           sentence, which
                                                                                           refers to an SSM
                                                                                           plan. SSM plans are
                                                                                           not required.
63.8(g)(1)-(g)(4)...................  .......................  Yes......................  Data reduction
                                                                                           requirements apply
                                                                                           only if you use CEMS
                                                                                           to demonstrate
                                                                                           compliance with
                                                                                           alternative standard
                                                                                           in Sec.
                                                                                           63.11496(e). COMS
                                                                                           requirements do not
                                                                                           apply. Requirement in
                                                                                           Sec.   63.8(g)(2)
                                                                                           does not apply
                                                                                           because data
                                                                                           reduction for CEMS
                                                                                           are specified in
                                                                                           subpart FFFF of this
                                                                                           part.
63.8(g)(5)..........................  .......................  No.......................  Data reduction
                                                                                           requirements for CEMS
                                                                                           are specified in Sec.
                                                                                             63.2450(j)(4), as
                                                                                           referenced from Sec.
                                                                                            63.11496. CPMS
                                                                                           requirements are
                                                                                           specified in subpart
                                                                                           SS of this part, as
                                                                                           referenced from Sec.
                                                                                            63.11496.
63.9(a), (b)(1), (b)(2), (b)(4),      Notification             Yes......................
 (b)(5), (c), (d), (e), (i).           Requirements.
63.9(b)(3), (h)(4)..................  Reserved...............  No.......................
63.9(f).............................  .......................  No.......................  This subpart does not
                                                                                           contain opacity or VE
                                                                                           limits.
63.9(g).............................  .......................  Yes......................  Additional
                                                                                           notification
                                                                                           requirement applies
                                                                                           only if you use CEMS
                                                                                           to demonstrate
                                                                                           compliance with
                                                                                           alternative standard
                                                                                           in Sec.
                                                                                           63.11496(e).
63.9(h)(1)-(h)(3), (h)(5)-(h)(6)....  .......................  Yes......................  Except as specified in
                                                                                           Sec.   63.11501(b)
                                                                                           and this subpart does
                                                                                           not contain opacity
                                                                                           or VE limits.
63.9(j).............................  Change in Information    No.......................  Notification of
                                       Already Provided.                                   process changes that
                                                                                           affect a compliance
                                                                                           determination are
                                                                                           required in Sec.
                                                                                           63.11501(d)(4).
63.9(k).............................  Electronic Submission    Yes......................  As specified in Sec.
                                       of Notifications or                                 Sec.
                                       Reports.                                            63.11496(g)(1)(iv),
                                                                                           63.11497(f)(1)(iv),
                                                                                           and 63.11501(b) and
                                                                                           (d).
63.10(a)............................  Recordkeeping            Yes......................
                                       Requirements.
63.10(b)(1).........................  .......................  Yes......................
63.10(b)(2)(i)......................  Recordkeeping of         No.......................  See Sec.
                                       Occurrence and                                      63.11501(c)(8) for
                                       Duration of Startups                                recordkeeping of
                                       and Shutdowns.                                      occurrence and
                                                                                           duration of each
                                                                                           startup and shutdown
                                                                                           for continuous
                                                                                           process vents that
                                                                                           are subpart to table
                                                                                           3 to this subpart.
63.10(b)(2)(ii).....................  Recordkeeping of         No.......................  See Sec.
                                       Malfunctions.                                       63.11501(c)(1)(vii)
                                                                                           and (viii) for
                                                                                           recordkeeping
                                                                                           requirements.
63.10(b)(2)(iii)....................  Maintenance Records....  Yes......................
63.10(b)(2)(iv) and (v).............  Actions Taken to         No.......................
                                       Minimize Emissions
                                       During SSM.
63.10(b)(2)(vi), (x), (xi), (xiii)..  .......................  Yes......................  Apply only if you use
                                                                                           CEMS to demonstrate
                                                                                           compliance with
                                                                                           alternative standard
                                                                                           in Sec.
                                                                                           63.11496(e).
63.10(b)(2)(vii)-(b)(2)(ix),          .......................  Yes......................
 (b)(2)(xii), (b)(2)(xiv).
63.10(b)(3).........................  .......................  Yes......................

[[Page 16538]]

 
63.10(c)(1), (c)(5)-(c)(6), (c)(13)-  .......................  Yes......................  Apply only if you use
 (c)(14).                                                                                  CEMS to demonstrate
                                                                                           compliance with
                                                                                           alternative standard
                                                                                           in Sec.
                                                                                           63.11496(e).
63.10(c)(7)-(8).....................  Additional               Yes......................
                                       Recordkeeping
                                       Requirements for CMS--
                                       Identifying
                                       Exceedances and Excess
                                       Emissions.
63.10(c)(10)........................  Recordkeeping Nature     No.......................  See Sec.
                                       and Cause of                                        63.11501(c)(1)(vii)
                                       Malfunctions.                                       and (viii) for
                                                                                           recordkeeping
                                                                                           requirements.
63.10(c)(11)........................  Recording Corrective     No.......................  See Sec.
                                       Actions.                                            63.11501(c)(1)(vii)
                                                                                           and (viii) for
                                                                                           recordkeeping
                                                                                           requirements.
63.10(c)(12)........................  .......................  Yes......................
63.10(c)(15)........................  Use of SSM Plan........  No.......................
63.10(c)(2)-(c)(4), (c)(9)..........  Reserved...............  No.......................
63.10(d)(1), (d)(4), (f)............  Reporting Requirements.  Yes......................
63.10(d)(2).........................  .......................  No.......................  See Sec.  Sec.
                                                                                           63.11496(g)(1)(iv)
                                                                                           and
                                                                                           63.11497(f)(1)(iv)
                                                                                           for performance test
                                                                                           reporting.
63.10(d)(3).........................  .......................  No.......................  This subpart does not
                                                                                           include opacity or VE
                                                                                           limits.
63.10(d)(5).........................  SSM Reports............  No.......................  See Sec.
                                                                                           63.11501(d)(1) and
                                                                                           (8) for reporting
                                                                                           requirements.
63.10(e)(1)-(e)(2)..................  .......................  Yes......................  Apply only if you use
                                                                                           CEMS to demonstrate
                                                                                           compliance with
                                                                                           alternative standard
                                                                                           in Sec.
                                                                                           63.11496(e).
                                                                                           Additionally, this
                                                                                           subpart specifies how
                                                                                           and when the
                                                                                           performance
                                                                                           evaluation results
                                                                                           are reported.
63.10(e)(3).........................  .......................  No.......................  Except as provided in
                                                                                           Sec.   63.11501(d).
63.10(e)(4).........................  .......................  No.......................  This subpart does not
                                                                                           include opacity or VE
                                                                                           limits.
63.11...............................  Control Device           Yes......................
                                       Requirements.
63.12...............................  State Authorities and    Yes......................
                                       Delegations.
63.13...............................  Addresses..............  Yes......................
63.14...............................  Incorporations by        Yes......................
                                       Reference.
63.15...............................  Availability of          Yes......................
                                       Information and
                                       Confidentiality.
63.16...............................  Performance Track        Yes......................
                                       Provisions.
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[FR Doc. 2026-06304 Filed 3-31-26; 8:45 am]
BILLING CODE 6560-50-P