National Emission Standards for Hazardous Air Pollutants: Primary Copper Smelting Residual Risk and Technology Review and Primary Copper Smelting Area Source Technology Review, 41648-41724 [2024-09883]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 89, Number 93 (Monday, May 13, 2024)]
[Rules and Regulations]
[Pages 41648-41724]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-09883]



[[Page 41647]]

Vol. 89

Monday,

No. 93

May 13, 2024

Part V





 Environmental Protection Agency





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40 CFR Part 63





 National Emission Standards for Hazardous Air Pollutants: Primary 
Copper Smelting Residual Risk and Technology Review and Primary Copper 
Smelting Area Source Technology Review; Final Rule

Federal Register / Vol. 89, No. 93 / Monday, May 13, 2024 / Rules and 
Regulations

[[Page 41648]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2020-0430; FRL-7522-02-OAR]
RIN 2060-AU63


National Emission Standards for Hazardous Air Pollutants: Primary 
Copper Smelting Residual Risk and Technology Review and Primary Copper 
Smelting Area Source Technology Review

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This action finalizes the residual risk and technology review 
(RTR) conducted for the Primary Copper Smelting major source category 
regulated under national emission standards for hazardous air 
pollutants (NESHAP). This action also finalizes the technology review 
for the Primary Copper Smelting area source NESHAP. The final 
amendments for the major source NESHAP include particulate matter (PM) 
emission standards as a surrogate for metal hazardous air pollutants 
(HAP) other than mercury (primarily lead and arsenic) for anode 
refining point sources, process fugitive emissions from roofline vents, 
Hoboken converter process fugitive capture systems where they combine 
with anode refining point sources, and new converters. We are also 
finalizing emission standards for previously unregulated HAP including 
mercury, benzene, toluene, hydrogen chloride (HCl), chlorine, 
polycyclic aromatic hydrocarbons (PAH), and dioxins and furans (D/F). 
In addition, we are taking final action in the major source NESHAP to 
establish work practice standards for bypass stacks, and add a new 
emissions limit for lead and emissions control design standards to 
minimize process fugitive emissions at facilities with flash furnaces 
and Peirce-Smith converters. Final amendments for both the major source 
NESHAP and the area source NESHAP include removing exemptions and 
associated provisions for periods of startup, shutdown, and malfunction 
(SSM), specifying that the emission standards apply at all times, and 
requiring electronic reporting of performance test results and 
notification of compliance reports.

DATES: This final rule is effective May 13, 2024, except for amendatory 
instruction 3, which is effective July 15, 2024. The incorporation by 
reference (IBR) of certain publications listed in the rule is approved 
by the Director of the Federal Register as of May 13, 2024.

ADDRESSES: The U.S. Environmental Protection Agency (EPA) has 
established a docket for this action under Docket ID No. EPA-HQ-OAR-
2020-0430. All documents in the docket are listed on the https://www.regulations.gov/website. Although listed, some information is not 
publicly available, e.g., Confidential Business Information or other 
information whose disclosure is restricted by statute. Certain other 
material, such as copyrighted material, is not placed on the internet 
and will be publicly available only in hard copy form. Publicly 
available docket materials are available either electronically through 
https://www.regulations.gov/, or in hard copy 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 Standard Time (EST), 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 questions about this final action, 
contact U.S. EPA, Attn: Amanda Hansen, Mail Drop: D243-04, 109 T.W. 
Alexander Drive, P.O. Box 12055, RTP, North Carolina 27711; telephone 
number: (919) 541-3165; email address: [email protected]. For 
specific information regarding the risk modeling methodology, contact 
U.S. EPA, Attn: James Hirtz, Mail Drop: C539-02, 109 T.W. Alexander 
Drive, P.O. Box 12055, RTP, North Carolina 27711; telephone number: 
(919) 541-0881; email address: [email protected].

SUPPLEMENTARY INFORMATION: Preamble acronyms and abbreviations. 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:

ACI activated carbon injection
ADEQ Arizona Department of Environmental Quality
ANSI American National Standards Institute
BTF beyond-the-floor
CAA Clean Air Act
CEDRI Compliance and Emissions Data Reporting Interface
CEMS continuous emissions monitoring system
CFR Code of Federal Regulations
CRA Congressional Review Act
CMS continuous monitoring systems
DCOT digital camera opacity technique
D/F dioxins and furans
DSI dry sorbent injection
EAF electric arc furnaces
EJ Environmental Justice
EPA Environmental Protection Agency
ERT Electronic Reporting Tool
FEM Federal equivalent method
FR Federal Register
FRM Federal reference method
GACT generally available control technology
gr/dscf grains per dry standard cubic feet
HAP hazardous air pollutants
HCl hydrogen chloride
HEM-4 Human Exposure Model, Version 1.5.5
HI hazard index
HQ hazard quotient
ICR information collection request
lbs pounds
lb/hr pounds per hour
LEAN Louisiana Environmental Action Network
MACT maximum achievable control technology
mg/dscm milligrams per dry standard cubic meter
MIR maximum individual risk
MTG Measurement Technology Group
NAAQS National Ambient Air Quality Standards
NAICS North American Industry Classification System
NESHAP National Emission Standards for Hazardous Air Pollutants
NTTAA National Technology Transfer and Advancement Act
OAR Office of Air and Radiation
OMB Office of Management and Budget
PAH polycyclic aromatic hydrocarbons
Pb lead
PDF portable document format
PM particulate matter
PRA Paperwork Reduction Act
RATA Relative Accuracy Test Audit
REL reference exposure level
RFA Regulatory Flexibility Act
RIN Regulatory Information Number
RTR risk and technology review
SIP state implementation plan
SO2 sulfur dioxide
SSM startup, shutdown, and malfunction
TEQ toxic equivalency quotient
TOSHI target organ-specific hazard index
tpy ton per year
ug/m\3\ micrograms per cubic meter
UMRA Unfunded Mandates Reform Act
UPL upper prediction limit
VCS voluntary consensus standards
WESP wet electrostatic precipitator

    Background information. On January 11, 2022 (87 FR 1616), and July 
24, 2023 (88 FR 47415), the EPA proposed revisions to the Primary 
Copper Smelting major source NESHAP based on our RTR. In this action, 
we are finalizing decisions and revisions for the major source rule. On 
January 11, 2022 (87 FR 1616), the EPA also proposed revisions to the 
Primary Copper Smelting area source NESHAP based on our technology 
review. In this action, we are also finalizing decisions and revisions 
for the area source rule.

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We summarize some of the more significant comments we timely received 
regarding the proposed rules and provide our responses in this 
preamble. A summary of all other public comments on the proposals and 
the EPA's responses to those comments is available in National Emission 
Standards for Hazardous Air Pollutant Emissions: Primary Copper 
Smelting Residual Risk and Technology Review and Primary Copper 
Smelting Area Source Technology Review: Summary of Public Comments and 
Responses, Docket ID No. EPA-HQ-OAR-2020-0430. ``Track changes'' 
versions of the regulatory language that incorporate the changes to the 
two rules in this action are available in the docket.
    Organization of this document. The information in this preamble is 
organized as follows:

I. General Information
    A. Executive Summary
    B. Does this action apply to me?
    C. Where can I get a copy of this document and other related 
information?
    D. Judicial Review and Administrative Reconsideration
II. Background
    A. What is the statutory authority for this action?
    B. What is the Primary Copper Smelting source category and how 
does the NESHAP regulate HAP emissions from the source category?
    C. What changes did we propose for the Primary Copper Smelting 
source category in our January 11, 2022, proposal and in our July 
24, 2023, supplemental proposal?
III. What is included in this final rule?
    A. What are the final rule amendments based on the risk review 
for the Primary Copper Smelting source category?
    B. What are the final rule amendments based on the technology 
review for the Primary Copper Smelting source category?
    C. What are the final rule amendments pursuant to CAA sections 
112(d)(2) and (3) for the Primary Copper Smelting source category?
    D. What are the final rule amendments addressing emissions 
during periods of startup, shutdown, and malfunction?
    E. What other changes have been made to the NESHAP?
    F. What are the effective and compliance dates of the standards?
IV. What is the rationale for our final decisions and amendments for 
the Primary Copper Smelting source category?
    A. Residual Risk Review for the Primary Copper Smelting Source 
Category
    B. Technology Review for the Primary Copper Smelting Source 
Category
    C. CAA Sections 112(d)(2) and (3) Revisions for the Primary 
Copper Smelting Source Category
    D. Final Rule Amendments Addressing Bypass Stack Emissions
    E. Final Rule Amendments Addressing Compliance Dates
    F. Other Major Comments
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?
    C. What are the cost impacts?
    D. What are the economic impacts?
    E. What are the benefits?
    F. What analysis of environmental justice did we conduct?
VI. Statutory and Executive Order Reviews
    A. Executive Orders 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act (PRA)
    C. Regulatory Flexibility Act (RFA)
    D. Unfunded Mandates Reform Act (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act (NTTAA) and 
1 CFR Part 51
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations and Executive Order 14096: Revitalizing Our Nation's 
Commitment to Environmental Justice for All
    K. Congressional Review Act (CRA)

I. General Information

A. Executive Summary

    This action presents the results of the U.S. Environmental 
Protection Agency (EPA or the Agency) residual risk and technology 
review (RTR) for the National Emission Standards for Hazardous Air 
Pollutants (NESHAP) for major source Primary Copper Smelters as 
required under the Clean Air Act (CAA). Pursuant to the CAA, this 
action also presents the results of the technology review for the 
Primary Copper Smelting area source NESHAP.
    Based on the results of the risk review, the EPA is finalizing a 
determination that risks from emissions of air toxics from this major 
source category are currently unacceptable. This unacceptable risk 
determination considers all health information, including the EPA's 
analysis of health risks associated with emissions of lead and arsenic 
from these facilities. The modeled exceedance of the lead National 
Ambient Air Quality Standard (NAAQS) of 0.15 ug/m\3\ at Freeport 
represents an important health metric in EPA's unacceptability 
determination for the Primary Copper source category. The EPA estimated 
that the highest modeled rolling 3-month concentration of lead at a 
residential location is 0.17 ug/m\3\ based on 2019 actual emissions and 
0.24 ug/m\3\ based on allowable emissions, at the Freeport facility, 
refer to appendix 1; section 9 of the Residual Risk Assessment for the 
Primary Copper Smelting Source Category in Support of the 2021 Risk and 
Technology Review Proposed Rule for additional details of the monitor 
to model comparison for this rule. The NAAQS off-site lead (Pb) monitor 
(at Miami Golf Course) recorded Pb levels for 2019 were below the NAAQS 
with a maximum 3-month Pb concentration at the monitor of 0.038 ug/
m\3\, while the modeled Pb concentration based upon actual emissions 
for this site was 0.045 ug/m\3\. This close alignment of the monitor 
with model results for the Miami Golf Course site provides us with 
additional confidence in our maximum off-site model concentration of 
0.17 ug/m\3\ at a residential location. The EPA also found that the 
maximum individual risk (MIR) of cancer was estimated to be 70-in-1 
million based on actual emissions and 90-in-1 million based on 
allowable emissions (driven by arsenic emissions), which is approaching 
the presumptive level of unacceptability of 100-in-1 million. In 
addition, the EPA found that the maximum acute hazard quotient (HQ) was 
7 (also driven by arsenic emissions). Considering all of the health 
risk information and factors discussed above, along with the risk 
information and uncertainties discussed in the 2022 proposed rule 
preamble (87 FR 1616), the EPA has determined that the current risks 
for this source category are unacceptable.
    To reduce risks to an acceptable level, the EPA is finalizing a new 
emission limit for particulate matter (PM) as a surrogate for 
particulate hazardous air pollutant (HAP) metals (such as lead and 
arsenic) in the major source NESHAP for a combination of process 
fugitive roofline emissions from the anode refining department, copper 
converter departments, slag cleaning vessels and smelting vessels (also 
known as smelting furnaces). This standard will achieve significant 
reductions of lead and arsenic emissions and their associated health 
risks (as described in section IV.A. of this preamble).
    Pursuant to the LEAN decision (which is described further in 
section II.A. of this preamble), the EPA is also finalizing new 
emissions standards based on maximum achievable control technology 
(MACT) for the major source NESHAP to address currently

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unregulated emissions of HAP, as follows: PM, as a surrogate for 
particulate HAP metals, for (1) anode refining furnace point source 
emissions; (2) new converters; and (3) the combination of process 
fugitive roofline emissions from the anode refining department, copper 
converter departments, slag cleaning vessels and smelting vessels (also 
known as smelting furnaces). The EPA is also finalizing new pollutant-
specific emissions limits based on MACT for the following HAP: mercury, 
lead, benzene, toluene, hydrogen chloride (HCl), chlorine, polycyclic 
aromatic hydrocarbons (PAH), naphthalene and dioxins and furans (D/F). 
Furthermore, in this final action, after reviewing and considering 
public comments, the EPA is finalizing work practice standards 
according to CAA 112(h) for bypass stacks which were previously an 
unregulated emissions source.
    Pursuant to the CAA mandated technology review, we are finalizing a 
PM limit (as a surrogate for nonmercury metal HAP) for the combined 
emissions from the Hoboken converter process fugitive capture systems 
where they combine with anode refining point source emissions. This 
standard will achieve significant reductions of lead and arsenic 
emissions (as described in sections III.B. and IV.B. of this preamble). 
Furthermore, we are finalizing emissions control design standards to 
minimize process fugitive HAP metals emissions from roof vents at 
facilities with flash furnaces and Peirce-Smith converters. In 
addition, under the technology review the EPA is finalizing work 
practice standards to minimize fugitive dust emissions which will 
achieve further emissions reductions beyond the reductions that will be 
achieved from the rooflines under the risk review for major sources 
(described above).
    With regard to primary copper smelting area sources, the Agency did 
not identify any developments in practices, processes, or control 
technologies. Therefore, the EPA is not finalizing any new or revised 
standards pursuant to the CAA technology review for the area source 
NESHAP.
    In addition to the new and revised standards described in the 
previous paragraphs, consistent with Sierra Club v. EPA (which is 
described further in section III.D. of this preamble), the EPA is also 
finalizing rule changes to remove exemptions and associated provisions 
for periods of startup, shutdown, and malfunction (SSM) and to specify 
that the emission standards apply at all times. The EPA is also 
finalizing rule changes to require electronic reporting of performance 
test results and notification of compliance reports for both area and 
major sources. Implementation of the rules is expected to reduce HAP 
metal emissions from primary copper smelters, improve human health, and 
reduce environmental impacts associated with those emissions. This 
final action will also result in improved monitoring, compliance, and 
implementation of the existing standards.
    During development of these proposed and final rules, the EPA also 
completed a demographic analysis which indicates that cancer risks 
associated with emissions from the major source category 
disproportionately affect communities with environmental justice 
concerns, including low-income residents, American Indians, and 
Hispanics living near these facilities. Once the new and revised 
standards (described in this preamble) are implemented, risks in nearby 
communities due to HAP emissions will be reduced to acceptable levels 
and the NESHAP will provide an ample margin of safety to protect public 
health.

B. Does this action apply to me?

    The source categories that are the subject of this action are 
Primary Copper Smelting Major Sources regulated under 40 CFR part 63, 
subpart QQQ, and Primary Copper Smelting Area Sources, regulated under 
40 CFR part 63, subpart EEEEEE. The North American Industry 
Classification System (NAICS) code for the primary copper smelting 
industry is 331410. This list of categories and NAICS codes is not 
intended to be exhaustive, but rather provides a guide for readers 
regarding the entities that this final action is likely to affect. The 
final standards will be directly applicable to the affected sources. 
State, local, and Tribal governments would not be directly affected by 
this final action. As defined in the Initial List of Categories of 
Sources Under Section 112(c)(1) of the Clean Air Act Amendments of 1990 
(see 57 FR 31576, July 16, 1992) and Documentation for Developing the 
Initial Source Category List, Final Report (see EPA-450/3-91-030, July 
1992), the Primary Copper Smelting major source category addresses any 
major source facility engaged in the pyrometallurgical process used for 
the extraction of copper from sulfur oxides, native ore concentrates, 
or other copper bearing minerals. As originally defined, the category 
includes, but is not limited to, the following smelting process units: 
roasters, smelting furnaces, and converters. Affected sources under the 
current major source NESHAP are concentrate dryers, smelting furnaces, 
slag cleaning vessels, converters, and fugitive emission sources. The 
area source category was added to the source category list in 2002 (67 
FR 70427, 70428). Affected sources under the area source NESHAP are 
concentrate dryers, smelting vessels (e.g., furnaces), converting 
vessels, matte drying and grinding plants, secondary gas systems, and 
anode refining operations.

C. Where can I get a copy of this document and other related 
information?

    In addition to being available in the docket, an electronic copy of 
this final action will also be available on the internet. Following 
signature by the EPA Administrator, the EPA will post a copy of this 
final action at https://www.epa.gov/stationary-sources-air-pollution/primary-copper-smelting-national-emissions-standards-hazardous-air and 
at https://www.epa.gov/stationary-sources-air-pollution/primary-copper-smelting-area-sources-national-emissions-standards. Following 
publication in the Federal Register, the EPA will post the Federal 
Register version and key technical documents at this same website.
    Additional information is available on the RTR website at https://www.epa.gov/stationary-sources-air-pollution/risk-and-technology-review-national-emissions-standards-hazardous. This information 
includes an overview of the RTR program and links to project websites 
for the RTR source categories.

D. Judicial Review and Administrative Reconsideration

    Under Clean Air Act (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 
(the Court) by July 12, 2024. Under CAA section 307(b)(2), the 
requirements established by this final rule may not be challenged 
separately in any civil or criminal proceedings brought by the EPA to 
enforce the requirements.
    Section 307(d)(7)(B) of the CAA further provides that only an 
objection to a rule or procedure which was raised with reasonable 
specificity during the period for public comment (including any public 
hearing) may be raised during judicial review. This section also 
provides a mechanism for the EPA to reconsider the rule if the person 
raising an objection can demonstrate to the Administrator that it was 
impracticable

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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.

II. Background

A. What is the statutory authority for this action?

    Section 112 of the CAA establishes a two-stage regulatory process 
to address emissions of HAP from stationary sources. In the first 
stage, we must identify categories of sources emitting one or more of 
the HAP listed in CAA section 112(b) and then promulgate technology-
based NESHAP for those sources. ``Major sources'' are those that emit, 
or have the potential to emit, any single HAP at a rate of 10 tons per 
year (tpy) or more, or 25 tpy or more of any combination of HAP. For 
major sources, these standards are commonly referred to as MACT 
standards and must reflect the maximum degree of emission reductions of 
HAP achievable (after considering cost, energy requirements, and non-
air quality health and environmental impacts). In developing MACT 
standards, CAA section 112(d)(2) directs the EPA to consider the 
application of measures, processes, methods, systems, or techniques, 
including, but not limited to, those that reduce the volume of or 
eliminate HAP emissions through process changes, substitution of 
materials, or other modifications; enclose systems or processes to 
eliminate emissions; collect, capture, or treat HAP when released from 
a process, stack, storage, or fugitive emissions point; are design, 
equipment, work practice, or operational standards; or any combination 
of the above.
    For these MACT standards, the statute specifies certain minimum 
stringency requirements, which are referred to as MACT floor 
requirements, and which may not be based on cost considerations. See 
CAA section 112(d)(3). For new sources, the MACT floor cannot be less 
stringent than the emission control achieved in practice by the best-
controlled similar source. The MACT standards for existing sources can 
be less stringent than floors for new sources, but they cannot be less 
stringent than the average emission limitation achieved by the best-
performing 12 percent of existing sources in the category or 
subcategory (or the best-performing five sources for categories or 
subcategories with fewer than 30 sources). In developing MACT 
standards, we must also consider control options that are more 
stringent than the floor under CAA section 112(d)(2). We may establish 
standards more stringent than the floor, based on the consideration of 
the cost of achieving the emissions reductions, any non-air quality 
health and environmental impacts, and energy requirements. Standards 
more stringent than the floor are commonly referred to as beyond-the-
floor (BTF) standards. In certain instances, as provided in CAA section 
112(h), the EPA may set work practice standards in lieu of numerical 
emission standards. For area sources, CAA section 112(d)(5) gives the 
EPA discretion to set standards based on generally available control 
technologies or management practices (Generally Available Control 
Technology (GACT) standards) in lieu of MACT standards.
    In the second stage of the regulatory process, the CAA requires the 
EPA to undertake two different analyses, which we refer to as the 
technology review and the residual risk review. Under the technology 
review, we must review the technology-based standards and revise them 
``as necessary (taking into account developments in practices, 
processes, and control technologies)'' no less frequently than every 8 
years, pursuant to CAA section 112(d)(6). In conducting this review, 
the EPA is not required to recalculate the MACT floors that were 
established in earlier rulemakings. Natural Resources Defense Council 
(NRDC) v. EPA, 529 F.3d 1077, 1084 (D.C. Cir. 2008). Association of 
Battery Recyclers, Inc. v. EPA, 716 F.3d 667 (D.C. Cir. 2013). The EPA 
may consider cost in deciding whether to revise the standards pursuant 
to CAA section 112(d)(6). The EPA is required to address regulatory 
gaps, such as missing standards for listed air toxics known to be 
emitted from the source category, and any new MACT standards must be 
established under CAA sections 112(d)(2) and (3), or, in specific 
circumstances, CAA sections 112(d)(4) or (h). Louisiana Environmental 
Action Network (LEAN) v. EPA, 955 F.3d 1088 (D.C. Cir. 2020). Under the 
residual risk review, we must evaluate the risk to public health 
remaining after application of the technology-based standards and 
revise the standards, if necessary, to provide an ample margin of 
safety to protect public health or to prevent, taking into 
consideration costs, energy, safety, and other relevant factors, an 
adverse environmental effect. The residual risk review is required 
within 8 years after promulgation of the technology-based standards, 
pursuant to CAA section 112(f). In conducting the residual risk review, 
if the EPA determines that the current standards provide an ample 
margin of safety to protect public health, it is not necessary to 
revise the MACT standards pursuant to CAA section 112(f).\1\ Section 
112(d)(5) of the CAA provides that this residual risk review is not 
required for categories of area sources subject to GACT standards. For 
more information on the statutory authority for this rule, see 87 FR 
1616 and 88 FR 47415.
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    \1\ The Court has affirmed this approach of implementing CAA 
section 112(f)(2)(A): NRDC v. EPA, 529 F.3d 1077, 1083 (D.C. Cir. 
2008) (``If EPA determines that the existing technology-based 
standards provide an `ample margin of safety,' then the Agency is 
free to readopt those standards during the residual risk 
rulemaking.'').
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B. What is the Primary Copper Smelting source category and how does the 
NESHAP regulate HAP emissions from the source category?

    The primary copper smelting source category includes any facility 
that uses a pyrometallurgical process to produce anode copper from 
copper ore concentrates. Primary copper smelting begins with copper 
mines supplying the ore concentrate (typically 30 percent copper). In 
most cases, the moisture is reduced from the ore concentrate in dryers, 
and then the ore concentrate is fed through a smelting furnace where it 
is melted and reacts to produce copper matte. One existing smelter is 
able to feed its copper concentrate directly to the smelting furnace 
without prior drying. Copper matte is a molten solution of copper 
sulfide mixed with iron sulfide and is about 60 percent copper. The 
solution is further refined using converters to make blister copper, 
which is approximately 98 percent copper. Converters use oxidation to 
remove sulfide as sulfur dioxide (SO2) gas and the iron as a 
ferrous oxide slag. The majority of the SO2 gases are sent 
to a sulfuric acid plant. The slag is removed, cooled, and often 
processed again to remove any residual copper. The blister copper is 
reduced in the anode furnace to remove impurities and oxygen, typically 
by injecting natural gas and steam, to produce a high purity

[[Page 41652]]

copper. The molten copper from the anode refining furnace is poured 
into molds and cooled to produce solid copper ingots called anodes. 
This process is known as casting. The anodes are sent to a copper 
refinery, either on-site or at an off-site location, for further 
purification using an electrolytic process to obtain high purity copper 
that is sold as a product.
    The processing units of interest at primary copper smelters, 
because of their potential to generate HAP emissions, are the 
following: dryers, smelting furnaces, copper converters, anode refining 
furnaces, and, if present, copper holding vessels, slag cleaning 
vessels, and matte drying and grinding plants. In addition, fugitive 
emissions are sources of HAP at primary copper smelters. The transfer 
of matte, converter slag, and blister copper is the primary source of 
fugitive emissions.
    There are three primary copper smelting facilities in the U.S. that 
are subject to the NESHAPs in this review. Two of the facilities, 
Asarco and Freeport (also referred to as FMMI), are both located in 
Arizona and are major sources of HAP emissions that are subject to 
subpart QQQ, the major source NESHAP. The third facility, Kennecott, is 
located in Utah and is an area source subject to subpart EEEEEE, the 
area source NESHAP.
    Two of the facilities (Asarco and Kennecott) use flash smelting 
furnaces (the INCO smelting furnace and the Outotec[supreg], 
respectively). Flash smelting furnaces consist of blowing fine, dried 
copper sulfide concentrate and silica flux with air, oxygen-enriched 
air or oxygen into a hot hearth-type furnace. The sulfide minerals in 
the concentrate react with oxygen resulting in oxidation of the iron 
and sulfur, which produces heat and therefore melting of the solids. 
The molten matte and slag are removed separately from the furnace as 
they accumulate, and at the facility using the INCO furnace, the matte 
is transferred via ladles to the copper converters. The Freeport 
facility uses an ISASMELT furnace. The ISASMELT process involves 
dropping wet feed through a feed port, such that dryers are not needed. 
A mixture of air, oxygen, and natural gas is blown through a vertical 
lance in the center of the furnace, generating heat and melting the 
feed. The molten metal is then tapped from the bottom and sent to an 
electric furnace to separate the matte from slag. The slag is removed 
from the electric furnace through tapholes and is transferred to slag 
pots via ladles. The matte is also removed from the electric furnace 
through tapholes and transferred to the converter via ladles.
    At the area source primary copper smelter, molten copper matte 
tapped from the Outotec[supreg] smelting furnace is not transferred as 
molten material directly to the converting vessel as is performed at 
the two major source smelters. Instead, the matte is first quenched 
with water to form solid granules of copper matte. These matte granules 
are then ground to a finer texture and fed to the flash converting 
furnace for the continuous converting of copper. The continuous copper 
converter differs significantly in design and operation from the 
cylindrical batch converters operated at the other U.S. smelters. 
Because there are no transfers of molten material between the smelting 
furnace and the continuous copper converter, this technology has 
inherently lower potential HAP emissions than a smelter using batch 
copper converting technology.
    In either a facility using batch copper converting or a facility 
using continuous copper converting, and as discussed above in this 
section, molten blister copper is next transferred from the converting 
vessel to an anode furnace for refining to further remove residual 
impurities and oxygen, and then poured into molds to produce solid 
copper ingots called anodes. The anode copper is sent to a copper 
refinery, either on-site or at another location, where it is further 
purified using an electrolytic process to obtain the high purity copper 
that is sold as a product. The copper refinery is not part of the 
primary copper smelting source category.
    The current NESHAP for major sources (40 CFR part 63, subpart QQQ) 
was proposed on April 20, 1998 (63 FR 19582), with a supplement to the 
proposed rule published on June 26, 2000 (65 FR 39326). The final rule, 
promulgated on June 12, 2002 (67 FR 40478), established PM standards as 
a surrogate for HAP metals for copper concentrate dryers, smelting 
furnaces, slag cleaning vessels, and existing converters. The major 
source NESHAP applies to major sources that use batch copper 
converters. Regarding new sources, the NESHAP prohibits batch 
converters for new sources, which indirectly means that any new source 
would need to have continuous converters, similar to the area source 
(Kennecott), or another technology. The converter building is subject 
to an opacity limit that only applies during performance testing. A 
fugitive dust plan is required to minimize fugitive dust emissions. 
Subpart QQQ also establishes requirements to demonstrate initial and 
continuous compliance with all applicable emission limitations, work 
practice standards, and operation and maintenance requirements. Annual 
performance testing is required to demonstrate compliance.
    The NESHAP for area sources (40 CFR part 63, subpart EEEEEE) 
establishes GACT standards for primary copper smelting area sources and 
was proposed on October 6, 2006 (71 FR 59302) and finalized on January 
23, 2007 (72 FR 2930). Technical corrections were then published on 
July 3, 2007, via direct final rule (72 FR 36363). The affected sources 
(i.e., copper concentrate dryers, smelting vessels, converting vessels, 
matte drying and grinding plants, secondary gas systems and anode 
refining departments) are subject to PM limits as a surrogate for HAP 
metals. Compliance is demonstrated by either continuously measuring PM, 
conducting a performance test every 2.5 years, or operating a PM 
continuous emission monitoring system (CEMS).

C. What changes did we propose for the Primary Copper Smelting source 
category in our January 11, 2022, proposal and in our July 24, 2023, 
supplemental proposal?

    On January 11, 2022, the EPA published a proposed rule in the 
Federal Register (87 FR 1616) for the NESHAP for Primary Copper 
Smelting, 40 CFR part 63, subpart QQQ, that took into consideration the 
RTR analyses and for the NESHAP for Primary Copper Smelting Area 
Sources, 40 CF part 63, subpart EEEEEE, that took into consideration 
the technology review. In the 2022 proposed rule, we proposed:
     PM limits based on the MACT floor for anode refining point 
sources at new and existing major sources;
     PM limits based on the MACT floor for process fugitive 
emissions from roofline vents of smelting furnaces at new and existing 
major sources;
     PM limits based on the MACT floor for process fugitive 
emissions from roofline vents of converters at new and existing major 
sources;
     PM limits based on beyond-the-floor (BTF) for process 
fugitive emissions from roofline vents at anode refining operations at 
new and existing major sources;
     PM limits based on the MACT floor for new converters at 
major sources;
     Facility-wide mercury limit based on BTF for any 
combination of stacks or other vents from the copper concentrate 
dryers, copper converter department, the anode refining department, and 
the smelting vessels at existing major sources;
     Facility-wide mercury limit based on the MACT floor for 
new major sources;

[[Page 41653]]

     Revisions to the existing fugitive dust control work 
practice standards to make them more robust than what is currently 
required by the major source NESHAP;
     Removal of SSM exemptions and associated provisions and 
specify that emissions standards apply at all times for both area 
sources and major sources; and
     Requirements for electronic reporting of performance test 
reports and notification of compliance reports for both area sources 
and major sources.
    During the comment period for the 2022 proposal, the EPA received 
public comments from industry, Tribal nations, environmental groups, 
Arizona Department of Environmental Quality (ADEQ), and private 
citizens. After reviewing the comments, and after consideration of 
additional data and information received since the 2022 proposal, the 
EPA determined it was appropriate to gather additional data, revise 
some of the analyses associated with that proposal, and to publish a 
supplemental proposal for the major source NESHAP.
    In support of the supplemental proposal, the EPA sent a section 114 
information request to the Freeport facility only, as the Asarco 
facility has been idled since October 2019. The section 114 information 
request was delivered to the Freeport facility on August 31, 2022. In 
response to this section 114 information request, the EPA received 
performance test results for the Freeport facility containing emission 
rates of benzene, 1,4-dichlorobenzene, chlorine, formaldehyde, hexane, 
hydrogen fluoride, hydrogen chloride, toluene, total hydrocarbons, PAH 
including naphthalene, and dioxins and furans. The section 114 
information request response from Freeport also provided data regarding 
costs and feasibility of installing additional controls for the aisle 
scrubber including a wet electrostatic precipitator (WESP) and a 
baghouse to control emissions from the Hoboken converter process 
fugitive capture system. Finally, the section 114 information request 
response from Freeport provided detailed information for input 
materials, emission sources, and process information.
    In addition to the information collected through the section 114 
information request, the EPA also received information during and after 
the public comment period of the 2022 proposed RTR. This additional 
information included cost estimates for the control devices which we 
expect would be needed to comply with the emission limits proposed in 
the 2022 proposal (e.g., for mercury, lead and arsenic). It also 
included additional performance testing results for the roofline vents, 
vent fume stack, aisle scrubber, and acid plant stack. Finally, 
Freeport also voluntarily performed an additional performance test for 
mercury in 2022 and submitted those results to the EPA.
    Based on evaluation of all the data, we proposed several revised 
and new MACT standards in a supplemental proposal published in the 
Federal Register (88 FR 47415) on July 24, 2023, pursuant to CAA 
sections 112(d)(2), (d)(3), (d)(6), and (f). For the supplemental 
proposal, which addressed only the major source NESHAP, we proposed:
     Benzene, toluene, HCl, chlorine, PAH, naphthalene and D/F 
limits based on the MACT floor for any new and existing combination of 
stacks or other vents from the copper concentrate dryers, copper 
converter department, the anode refining department, and the smelting 
vessels at major sources based on test data submitted by the only 
operating major source;
     Revisions to the proposed PM limits for process fugitive 
emissions from roofline vents of smelting vessels, converters, and 
anode refining operations at new and existing sources to provide a 
combined emission limit for all roofline vents based on additional test 
data and comments submitted by affected facilities;
     Revisions to the proposed mercury limits for any new and 
existing combination of stacks or other vents from the copper 
concentrate dryers, converting department, the anode refining 
department, and the smelting vessels to provide a limit based on the 
MACT floor after considering additional test data and comments 
submitted by affected facilities; and
     Prohibition of the use of bypass stacks for major sources.
    We also co-proposed two options for further controlling HAP metals 
at the aisle scrubber source at Freeport as follows:
     Option 1--PM limits based on the addition of a WESP 
downstream of the aisle scrubber to provide additional control of the 
combined emissions stream from the secondary capture system for the 
converter department \2\ and the anode refining department (i.e., the 
same option evaluated by the EPA in the ample margin of safety analysis 
included in the January 2022 proposal);
---------------------------------------------------------------------------

    \2\ Based on comments on the supplemental proposal, this system 
should be referred to as a process fugitive capture system for the 
Hoboken converters; we are clarifying this terminology in the final 
rule.
---------------------------------------------------------------------------

     Option 2--PM limits based on the addition of a baghouse 
upstream of the aisle scrubber to provide additional control of the 
secondary capture system for the converter department.

III. What is included in this final rule?

    This action finalizes the EPA's determinations pursuant to the RTR 
provisions of CAA section 112 for the Primary Copper Smelting major 
source category and amends the Primary Copper Smelting major source 
NESHAP, 40 CFR part 63, subpart QQQ, based on those determinations. The 
changes being finalized for the major sources in this action include 
promulgation of MACT floor-based PM limits for the anode refining 
department point source emissions; BTF PM limits to address process 
fugitive emissions from the smelting vessels, copper converter 
department, and anode refining roofline vents combined; MACT floor-
based PM limits for new copper converter departments; MACT floor-based 
emission standards for previously unregulated HAP (e.g., mercury, 
benzene, toluene, HCl, chlorine, PAH, naphthalene and D/F); and PM 
limits for the combined anode refining department and Hoboken converter 
process fugitive capture systems. This action also finalizes design 
standards to limit HAP metals and a BTF lead emissions limit to 
minimize process fugitive emissions from roofline vents for certain 
processes. In addition, this action finalizes work practice standards 
for the use of bypass stacks and revisions to the fugitive dust control 
plan requirements. This action also finalizes other changes to the 
major source NESHAP including electronic reporting requirements and the 
removal of SSM exemptions. This final action includes several changes 
to the proposed requirements in the 2022 proposal and 2023 supplemental 
proposal based on consideration of comments and information received 
during the public comment periods as described in section IV. of this 
preamble.
    This action also finalizes the EPA's determination pursuant to the 
technology review provisions of CAA section 112 for the Primary Copper 
Smelting area source category. We determined that there are no 
developments in practices, processes, and control technologies that 
warrant revisions to the NESHAP for Primary Copper Smelting Area 
Sources, 40 CFR part 63, subpart EEEEEE, pursuant to CAA section 
112(d)(6). However, this action finalizes amendments to the area

[[Page 41654]]

source NESHAP to remove SSM exemptions and associated provisions and 
provide electronic reporting requirements.

A. What are the final rule amendments based on the risk review for the 
Primary Copper Smelting source category?

    This section introduces the final amendments to the Primary Copper 
Smelting NESHAP, 40 CFR part 63, subpart QQQ, being promulgated 
pursuant to CAA section 112(f). The EPA is promulgating a PM emission 
limit (as a surrogate for HAP metals other than mercury) of 6.3 pounds 
per hour (lb/hour) for process fugitive emissions from roofline vents 
of the smelting vessels, copper converter departments, slag cleaning 
vessels and anode refining departments combined, at new and existing 
sources. This emission limit is the same as proposed in the 2023 
supplemental proposal. This combined PM emission limit for process 
fugitive emissions from roofline vents is also being promulgated under 
CAA section 112(d)(2) and (d)(3) as described in section III.C. of this 
preamble.

B. What are the final rule amendments based on the technology review 
for the Primary Copper Smelting source category?

    We determined that there are developments in practices, processes, 
and control technologies that warrant revisions to the MACT standards 
for this source category. Therefore, to satisfy the requirements of CAA 
section 112(d)(6), we are revising the MACT standards to include a 
combined emission standard for the anode refining department point 
source emissions and Hoboken converter process fugitive capture system 
of 4.1 milligrams per dry standard cubic meter (mg/dscm). The 
promulgated standard was co-proposed in the 2023 supplemental proposal 
as one of the two options expected to require additional controls of 
the combined emission streams. The promulgated standard is expected to 
require the installation of PM controls (such as a baghouse) to control 
the emissions from the Hoboken converter process fugitive capture 
system before this emission stream combines with the anode refining 
department point source exhaust in the aisle scrubber.
    We are also promulgating, as proposed in the 2022 proposal, 
amendments to the existing requirements for facilities to develop and 
implement a fugitive dust control plan pursuant to CAA section 
112(d)(6) as part of technology review.
    In addition, the EPA is promulgating a lead emission limit of 0.326 
lb/hour under CAA section 112(d)(2) and (3) and design standards under 
CAA section 112(d)(6) for minimizing process fugitive emissions from 
any combination of roofline vents associated with the Peirce-Smith 
copper converter department, Inco flash furnace and the anode refining 
department, at new and existing sources. The design standards are being 
promulgated for the flash furnace area capture system, fuming ladle 
capture system, and the anode furnace secondary hood capture and 
control system to further reduce process fugitive HAP metals at 
facilities with a combination of the Peirce-Smith copper converter 
department, Inco flash furnace and the anode refining department. We 
note that the combined lead emission limit for reducing process 
fugitive emissions from roofline vents is being promulgated under CAA 
section 112(d)(2) and (d)(3) as described in section III.C. of this 
preamble. However, the design standards are being promulgated under CAA 
section 112(d)(6).
    As part of the technology review for the major source NESHAP, we 
also identified regulatory gaps (previously unregulated processes or 
pollutants) and are establishing new standards to fill those gaps as 
described in section III.C. of this preamble.

C. What are the final rule amendments pursuant to CAA sections 
112(d)(2) and (3) for the Primary Copper Smelting source category?

    Pursuant to CAA sections 112(d)(2) and (3), we are promulgating 
MACT floor limits for emissions of PM (as a surrogate for HAP metals 
other than mercury) from new and existing anode refining departments 
and new copper converter departments, which were previously unregulated 
sources of HAP metals. We are also promulgating, pursuant to CAA 
sections 112(d)(2) and (3), a BTF limit for emissions of PM (as a 
surrogate for HAP metals other than mercury) from new and existing 
sources of process fugitive emissions from the roofline vents from the 
smelting vessels, slag cleaning vessels, the copper converter 
department, and the anode refining department combined, which were 
previously unregulated sources of HAP metals. As described in section 
III.A. of this preamble, the emissions standard for new and existing 
sources of process fugitive gases from the roofline vents from the 
smelting vessels, slag cleaning vessels, the converter department, and 
the anode refining department is also being finalized pursuant to CAA 
section 112(f)(2) to address the source category unacceptable risk 
determination. In addition, we are also promulgating, pursuant to CAA 
sections 112(d)(2) and (3), a BTF lead emission limit to minimize 
process fugitive emissions from any combination of roofline vents 
associated with the Peirce-Smith copper converter department, Inco 
flash furnace and the anode refining department. Lastly, we are 
promulgating, pursuant to CAA sections 112(d)(2) and (3), MACT emission 
limits for mercury, benzene, toluene, HCl, chlorine, PAH excluding 
naphthalene, naphthalene, and D/F, all of which were previously 
unregulated HAP. A summary of the MACT standards promulgated pursuant 
to CAA sections 112(d)(2) and (3) is provided in table 1 below. For 
more information on these standards, including their rationale, see 
section IV.C. of this preamble.
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[[Page 41656]]


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BILLING CODE 6560-50-C

D. What are the final rule amendments addressing emissions during 
periods of startup, shutdown, and malfunction?

    We are finalizing the elimination of SSM exemptions and associated 
provisions in the Primary Copper Smelting NESHAPs (40 CFR part 63, 
subparts QQQ and EEEEEE) as proposed in the 2022 proposal, other than 
clarifications and other non-substantive updates in SSM exemption 
removal explanation and provisions. In its 2008 decision in Sierra Club 
v. EPA, 551 F.3d 1019 (D.C. Cir. 2008), the court vacated portions of 
two provisions in the EPA's CAA section 112 regulations governing the 
emissions of HAP during periods of SSM. Specifically, the court vacated 
the SSM exemption contained in 40 CFR 63.6(f)(1) and (h)(1), holding 
that under section 302(k) of the CAA, emissions standards or 
limitations must be continuous in nature and that the SSM exemption 
violates the CAA's requirement that some section 112 standards apply 
continuously. Consistent with Sierra Club v. EPA, the EPA is 
establishing standards in these rules that apply at all times. We have 
revised table 1 (the General Provisions Applicability Table) in both 
rules in several respects related to SSM. For example, we have 
eliminated the incorporation of the General Provisions requirement that 
the sources develop an SSM plan, changed several references related to 
requirements that apply during periods of SSM, and eliminated or 
revised certain recordkeeping and reporting requirements related to the 
eliminated SSM exemption. The EPA also made changes to the rules to 
remove or modify inappropriate, unnecessary, or redundant language in 
the absence of the SSM exemption. See the 2022 proposed rule for 
additional information on removal of SSM exemptions. In addition, for 
40 CFR part 63, subpart QQQ, we are finalizing a work practice standard 
allowing the venting of process gases through a bypass stack during 
planned maintenance events under limited conditions as described in 
section IV.D.

E. What other changes have been made to the NESHAP?

1. Electronic Reporting
    To increase the ease and efficiency of data submittal and data 
accessibility, the EPA is finalizing, as proposed in the 2022 proposal, 
a requirement that owners and operators of sources subject to the 
Primary Copper Smelting NESHAP for major sources (subpart QQQ) submit 
electronic copies of required performance test reports and performance 
evaluations of continuous monitoring systems (CMS) measuring relative 
accuracy test audit (RATA) pollutants (being finalized at 40 CFR 
63.1455) through the EPA's Central Data Exchange (CDX) using the 
Compliance and Emissions Data Reporting Interface (CEDRI). A 
description of the electronic data submission process is provided in 
the memorandum 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 action (Docket ID No. EPA-HQ-OAR-2020-0430-0031). The final rule 
requires that performance test results or performance evaluation of CMS 
measuring RATA pollutants collected using test methods that are 
supported by the EPA's Electronic Reporting Tool (ERT) as listed on the 
ERT website \3\ at the time of the test be submitted in the format 
generated through the use of the ERT; or alternatively, owners or 
operators may submit an electronic file consistent with the extensible 
markup language (XML) schema listed on the EPA's ERT website. Other 
performance tests or performance evaluations of CMS measuring RATA 
pollutants collected using test methods that are not supported by the 
EPA's ERT as listed on the EPA's ERT website at the time of the test 
must be included as an attachment in the ERT or an alternate electronic 
file consistent with the XML schema listed on the EPA's ERT website. 
The final rule also requires that notification of compliance reports be 
submitted as a portable document format (PDF) upload in CEDRI.
---------------------------------------------------------------------------

    \3\ https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert.
---------------------------------------------------------------------------

    We are finalizing the electronic reporting requirements for the 
Primary Copper Smelting NESHAP for area sources (40 CFR part 63, 
subpart EEEEEE) as proposed in the 2022 proposal. The electronic 
reporting requirements are in 40 CFR 63.11147, 63.11148, and 63.11149 
of the rule, and include electronic reporting requirements for monthly 
emissions reports, emergency notifications, notifications of a 
deviation, semi-annual monitoring reports; and performance tests, where 
applicable.
2. Other Changes
    The EPA is finalizing, as proposed in the 2022 proposal, the 
revision to the applicability description under Sec.  63.1441 to 
clarify that the NESHAP applies to major source smelting facilities 
that use any type of converter, not just batch converters because the 
current definition limits applicability to only major sources that use 
batch converters. The major source NESHAP should apply to any Primary 
Copper major source regardless of what type of converter they use. 
Therefore, we are finalizing this change.
    Regarding revisions to testing requirements, the Agency is 
finalizing, as proposed in the 2022 proposal,

[[Page 41657]]

revisions to the wording in Sec.  63.1450 clarifying that facilities 
must test for filterable particulate, not total particulate. The test 
methods in Sec.  63.1450(a) have not changed for PM from the existing 
regulation. The methods in the existing regulation (Methods 5, 5D, and 
17) are methods for filterable PM. Total PM includes filterable PM and 
condensable PM. The condensable PM test method (Method 202) is not 
included in the existing regulation for the emission standards set in 
2002. In conjunction with clarifying that facilities must test for 
filterable particulate, not total particulate, we are changing all 
instances of the wording ``total particulate matter'' in the current 
rule to ``filterable particulate matter.''
    The Agency is finalizing, as proposed in the 2022 proposal and 2023 
supplemental proposal, the addition of appropriate test methods for 
PM10, fugitive PM, mercury, benzene, toluene, chlorine, 
hydrogen chloride, PAH excluding naphthalene, naphthalene, and dioxins/
furans, as well as updating test methods that are incorporated by 
reference because the affected facilities will need to know what test 
methods they need to use to demonstrate compliance with the new 
standards.
    Finally, the EPA is finalizing, as proposed in the 2022 proposal, 
to revise the definitions under Sec.  63.1459 by changing the term 
``smelting furnace'' to ``smelting vessel'' to be consistent with the 
definition in the area source rule, 40 CFR part 63, subpart EEEEEE, 
because we find it is appropriate that both rules include the broader 
definition of smelting vessel, which is already in the area source 
rule. The specific definition is as follows: Smelting vessel means a 
furnace, reactor, or other type of vessel in which copper ore 
concentrate and fluxes are smelted to form a molten mass of material 
containing copper matte and slag. Other copper-bearing materials may 
also be charged to the smelting vessel.

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

    For the additional MACT floor emission limits (mercury, HCl, 
chlorine, D/F, benzene, toluene, PAHs excluding naphthalene, and 
naphthalene) in 40 CFR part 63, subpart QQQ, the EPA is finalizing, as 
proposed in the 2023 supplemental proposal, the requirement that 
existing facilities must comply with these limits within 1 year after 
promulgation because we estimated both facilities can meet these MACT 
floor limits without having to install new controls. Similarly, for the 
new PM emission standard for anode refining point sources where the 
anode emissions are not combined with Hoboken converter process 
fugitive capture system emissions in an aisle scrubber, the Agency is 
finalizing, as proposed in the 2022 proposal, the proposed requirement 
that existing facilities must comply within 1 year after promulgation 
of the final rule as major source facilities that do not combine their 
anode point source emissions are expected to meet the limit without 
additional controls. For anode refining point sources that combine 
their anode emissions with Hoboken converter process fugitive capture 
system emissions in an aisle scrubber, compliance with the anode 
refining point source limit will be demonstrated through compliance 
with the combined PM limit at the aisle scrubber outlet and its 
associated compliance date.
    For the combined PM limit at the aisle scrubber outlet, which 
treats combined emissions from the Hoboken converter process fugitive 
capture system and anode refining point source, the EPA is finalizing 
that facilities must comply with this limit within 3 years after 
promulgation of the final rule. We are allowing up to 3 years to meet 
this limit as we expect facilities will need up to 3 years to design, 
construct and operate the necessary capture and control equipment to 
meet the limit.
    For the combined process fugitive PM roofline emissions limit for 
copper converter departments, anode refining departments, slag cleaning 
vessels and smelting vessel roofline vents, the EPA is finalizing, as 
proposed in the 2023 supplemental proposal, the requirement that 
existing facilities comply with this limit within 2 years after 
promulgation of the final rule. We are allowing up to two years to meet 
this limit as we expect facilities will need up to 2 years to design, 
construct and operate the necessary capture and control equipment to 
meet the limit.
    For the combined process fugitive lead roofline emissions limit for 
Peirce-Smith copper converter department, Inco flash furnace and the 
anode refining department roofline vents, the EPA is finalizing that 
facilities must comply with this limit within 3 years after 
promulgation of the final rule. We are allowing up to 3 years to meet 
this limit as we expect facilities will need up to 3 years to design, 
construct and operate the necessary capture and control equipment to 
meet the limit.
    For all other changes in this action we are finalizing, as 
proposed, that existing facilities must comply within 180 days after 
promulgation of the final rule.
    New sources must comply with all of the standards immediately upon 
the effective date of the standard, May 13, 2024, or upon startup, 
whichever is later.
    We are also finalizing amendments to Sec. Sec.  63.1442 and 63.1443 
and adding a new table (table 4 to 40 CFR part 63, subpart QQQ) which 
provides the applicability dates for previously unregulated affected 
sources (e.g., anode refining department, bypass stack), as well as the 
effective dates and compliance dates for the emission standards 
proposed in the 2022 proposal and 2023 supplemental proposal which are 
being promulgated in this final action.

IV. What is the rationale for our final decisions and amendments for 
the Primary Copper Smelting source category?

    For each issue, this section provides a description of what we 
proposed and what we are finalizing for the issue, 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, comment 
summaries and the EPA's responses can be found in the National Emission 
Standards for Hazardous Air Pollutant Emissions: Primary Copper 
Smelting Residual Risk and Technology Review and Primary Copper 
Smelting Area Source Technology Review: Summary of Public Comments and 
Responses document, available in the docket for this action (Docket ID 
No. EPA-HQ-OAR-2020-0430).

A. Residual Risk Review for the Primary Copper Smelting Source Category

1. What did we propose pursuant to CAA section 112(f) for the Primary 
Copper Smelting source category?
    Pursuant to CAA section 112(f), the EPA conducted a residual risk 
review and presented the results of this review, along with the 
proposed decisions regarding risk acceptability and ample margin of 
safety, in the January 11, 2022, proposed rule (87 FR 1616). In the 
2022 proposed rule, the EPA determined that risks from the primary 
copper smelting source category were unacceptable due to HAP metal 
(primarily lead and arsenic) emissions. Based on new information and 
data received after the 2022 proposal through the comment period and 
issuance of a 2022 CAA section 114 information request from the 
Freeport facility, the EPA updated the baseline risk assessment, 
updated control Option 1, and added a new control Option 2 that 
affected the Freeport facility only. The Asarco facility has been idle 
since October 2019, and therefore, a section

[[Page 41658]]

114 information request was not issued to them. The risk results for 
the Asarco facility did not change in the 2023 supplemental proposal 
because we did not receive any new data or information after the 2022 
proposal was published and before the supplemental proposal was 
published.
    The results of the risk assessment for the 2022 proposal are 
described in more detail in the Residual Risk Assessment for the 
Primary Copper Smelting Major Source Category in Support of the 2021 
Risk and Technology Review Proposed Rule document, which is available 
in the docket (Docket ID No. EPA-HQ-OAR-2020-0430-0051). The results of 
the baseline risk assessment for the 2023 supplemental proposal are 
presented in table 2 and in more detail in the residual risk document, 
Revised Residual Risk Assessment for the Freeport Smelter (Miami, AZ) 
in Support of the 2023 Supplemental Proposal for the Primary Copper 
Smelting Source Category, which is available in the Docket for this 
action (Docket ID No. EPA-HQ-OAR-2020-0430-0187).
[GRAPHIC] [TIFF OMITTED] TR13MY24.103

    A refined modeling analysis for the 2022 proposal was conducted at 
the facility with the highest annual concentration of lead, Freeport, 
to characterize ambient concentrations of lead for 3-month intervals. 
The maximum 3-month concentration was predicted for each off-site 
receptor. The concentrations were then compared to the Pb NAAQS of 0.15 
micrograms per cubic meter (ug/m3). The maximum 3-month off-site 
modeled concentration was 0.17 ug/m3 for actual emissions and 0.24 ug/
m3 for allowable emissions, and these results occurred near the 
Freeport facility. These results did not change in the 2023 
supplemental proposal.
    The inhalation risk assessment in the 2023 supplemental proposal 
estimated that the baseline cancer maximum individual risk (MIR) was 
70-in-1 million for the source category based on actual emissions. The 
total estimated cancer incidence from the source category was 0.002 
excess cancer cases per year, or one excess case every 500 years, with 
arsenic compounds contributing 97 percent of the cancer incidence for 
the source category in the 2023 supplemental proposal. Approximately 
22,900 people of the 46,460 people within 50 km of the facility were 
estimated to have cancer risks above 1-in-1 million from HAP emitted 
from the source category. The HEM-4 model predicted the maximum chronic 
noncancer hazard index (HI) value for the source category was 1 
(developmental), with an acute non-cancer HQ value equal to 7 driven by 
emissions of arsenic from the anode refining roofline at Freeport and, 
to a lesser degree, the anode furnace point source and Hoboken 
converter process fugitive capture system emissions emitted through the 
aisle scrubber at Freeport.
    The inhalation risk assessment based on MACT-allowable emissions 
did not change from the 2022 proposal and indicated that the cancer MIR 
was 90-in-1 million. The total estimated cancer incidence from the 
source category was

[[Page 41659]]

0.003 excess cancer cases per year, or one excess case every 333 years, 
with arsenic contributing 90 percent and cadmium contributing 8 percent 
of the cancer incidence for the source category. Approximately 29,001 
people were estimated to have cancer risks above 1-in-1 million from 
exposure to HAP emissions if HAP were emitted at the levels allowed 
under the NESHAP as it existed prior to finalization of this regulatory 
action. The chronic non-cancer risks remained the same as actuals, with 
acute non-cancer hazards not being modeled due to the uncertainty of 
estimating acute impacts based upon hourly allowable emission 
estimates.
    Regarding multipathway risk, we concluded in the 2022 proposal that 
there was no significant potential for multipathway health effects 
based upon EPA's Tier 3 screening analysis. Due to the conservative 
nature of the screens and the level of additional refinements that 
would go into a site-specific multipathway assessment, were one to be 
conducted, we are confident that the
    HQ for ingestion exposure, specifically cadmium and mercury through 
fish ingestion, is less than 1. For arsenic, maximum cancer risk posed 
by fish ingestion would also be reduced to levels below 1-in-1 million, 
and maximum cancer risk under the rural gardener scenario would 
decrease to 20-in-1 million or less. The estimated risks for the garden 
scenario seem unlikely due to the arid climate of the area and the 
hypothetical nature of the scenario. Further details on the Tier 3 
screening assessment can be found in Appendix 10-11 of Residual Risk 
Assessment for the Primary Copper Smelting Major Source Category in 
Support of the Risk and Technology Review 2021 Proposed Rule.
    In the 2023 supplemental proposal, we estimated that the 
multipathway and inhalation risk results would be reduced further due 
to baseline arsenic emissions at proposal (2022) being lowered based 
upon additional data being received. We also estimated in the 2023 
supplemental proposal that, although the mercury emissions increased 
from the 2022 proposal baseline, the mercury HQ would still be less 
than 1 (0.2) for the fisher scenario.
    For the 2023 supplemental proposal, the Agency weighed all the 
health risk factors in the risk acceptability determination and 
proposed that the risks from the Primary Copper Smelting source 
category are unacceptable at baseline. To address the unacceptable 
risks, in the supplemental proposal, we proposed a combined PM emission 
limit for process fugitive emissions from roofline vents of smelting 
furnaces, converters, and anode refining operations, which would 
significantly reduce risks. We estimated in the supplemental proposal 
that this combined PM limit would reduce emissions of HAP metal 
(primarily lead and arsenic) by 4.59 tpy. To be able to comply with the 
limit, we estimated that the Freeport facility would need to install 
controls (e.g., improved capture system, including hoods, ductwork, and 
fans, and one additional baghouse) to reduce process fugitive roofline 
emissions from the anode refining source, the main risk driver. As 
described in the supplemental proposal, we estimated that these 
controls would reduce the MIR at Freeport from 70-in-1 million to an 
estimated 20-in-1 million and that the acute noncancer HQ (for arsenic) 
would be reduced from 7 to 2 (based on actual emissions). In addition, 
the modeled lead concentrations would be reduced below the NAAQS. We 
estimated that the MIR for Asarco would remain at 60-in-1 million and 
would be the source category MIR after the proposed controls are 
applied at Freeport. In the supplemental proposal, we concluded that 
these risks, after implementation of proposed controls, were 
acceptable. We also proposed that existing facilities would need to 
comply within two years after promulgation of the final rule and new 
facilities must comply with all requirements in the final rule upon 
start up. We proposed that compliance would be demonstrated through an 
initial performance test followed by a compliance test once per year.
    We then considered whether the Primary Copper Smelting NESHAP 
provides an ample margin of safety to protect public health and whether 
more stringent standards are necessary to prevent an adverse 
environmental effect, taking into consideration costs, energy, safety, 
and other relevant factors. In considering whether the standards should 
be tightened to provide an ample margin of safety to protect public 
health, we considered the same risk factors that we considered for our 
acceptability determination and also considered the costs, 
technological feasibility, and other relevant factors related to 
emissions control options that might reduce risks associated with 
emissions from the source category.
    As discussed in the 2023 supplemental proposal, pursuant to CAA 
section 112(d)(6) and to provide an ample margin of safety to protect 
public health pursuant to CAA section 112(f)(2), the EPA co-proposed 
two regulatory options for additional control of either the secondary 
capture system for the converter department \4\ or additional control 
of the combined emissions stream of the secondary capture system for 
the converter department and the point source emissions from the anode 
refining department. For Option 1, a WESP would be located downstream 
of the aisle scrubber and therefore further control the combined 
emissions stream of the secondary capture system for the converter 
department and the point source emissions from the anode refining 
department. Under Option 2, a baghouse would be installed upstream of 
the aisle scrubber to provide additional control of the secondary 
capture system for the converter department. The EPA proposed that 
these control options would result in more stringent emission standards 
for these emission sources than were currently required in 40 CFR part 
63, subpart QQQ.
---------------------------------------------------------------------------

    \4\ Based on cmments on the supplement proposal, this system 
should be referred to as a roofline capture sysem for the Hoboken 
converters; we are claarifying this termionlogy in the final rule.
---------------------------------------------------------------------------

    In the 2022 proposal, the EPA evaluated additional work practices 
to reduce fugitive dust emissions, and the Agency found that the 
implementation of a more robust fugitive dust plan would result in an 
unquantified reduction of HAP, and we therefore proposed this 
requirement in the 2022 proposal. In the 2022 proposal, the EPA 
proposed that the combination of the standards for anode refining roof 
vents, fugitive dust plan and all other current standards in the NESHAP 
would ensure the NESHAP provides an ample margin of safety to protect 
public health.
2. How did the risk review change for the Primary Copper Smelting 
source category?
    While reviewing the information provided during the 2023 
supplemental proposal public comment period and reviewing the data 
provided during the section 114 process, a correction was made to the 
spreadsheet used to calculate the average emissions from the aisle 
scrubber based on stack tests provided by Freeport. The correction 
resulted in a slightly lower average arsenic emission rate for this 
source (from 0.626 tpy in the supplemental proposal to 0.563 tpy in the 
final rule), and therefore we re-modeled the baseline and roofline vent 
control scenarios as well as the two control options for the aisle 
scrubber. In addition to the corrected emission rate for the aisle 
scrubber, the EPA re-evaluated the estimated control efficiencies of 
the control options co-

[[Page 41660]]

proposed for the aisle scrubber source at Freeport based on the 
comments and information received on the supplemental proposal. These 
comments and our responses are discussed further in section IV.A.3. of 
this preamble.
    As discussed in the memorandum Cost Estimates for Additional 
Controls of Freeport's Aisle Scrubber--REVISED, which is available in 
the docket for this action, and as further discussed in section IV.B. 
of this preamble, we updated the control efficiency estimates for the 
aisle scrubber control options. In the 2023 supplemental proposal, we 
estimated that under Option 1, installing a WESP downstream of the 
aisle scrubber would achieve 95 percent control efficiency, and we 
estimated 6.3 tpy metal HAP reductions. Based on the comments received 
from Freeport regarding the technical feasibility of controlling the 
high-volume aisle scrubber exhaust stream using a WESP and our 
evaluation of those comments, we updated the estimated control 
efficiency for the WESP option to 73 percent, and we now estimate 4.9 
tpy metal HAP reduced. In the 2023 supplemental proposal, we estimated 
that under Option 2 (Baghouse option), installing a baghouse upstream 
of the aisle scrubber to control the Hoboken converter process fugitive 
capture system gas stream for the copper converter department would 
reduce metal HAP emissions by 4.5 tpy. Note that in the supplemental 
proposal, we referred to the process fugitive capture system as a 
``secondary'' capture system. However, Freeport commented that the 
capture system is better characterized as a tertiary capture system. 
Therefore, for the remainder of this preamble, we refer to this capture 
system as the Hoboken converter process fugitive capture system. 
Furthermore, based on comments received from Freeport in response to 
the 2023 supplemental proposal regarding the technical feasibility of 
controlling the high-volume Hoboken converter process fugitive capture 
system using a baghouse and our evaluation of those comments, we now 
estimate the baghouse will achieve 61 percent control efficiency of the 
Hoboken converter process fugitive capture system gas stream, and using 
the same assumption that this gas stream contributes 75 percent to the 
aisle scrubber, we estimate that HAP metals will be reduced under this 
option by 3.0 tpy (which represents an overall control efficiency of 46 
percent for the aisle scrubber). Therefore, the modeling conducted in 
support of the final rule was updated to reflect these new control 
efficiencies. The results of the updated modeling for the aisle 
scrubber control options, in addition to our consideration of public 
comment on this issue, resulted in a change to what we proposed for 
ample margin of safety. The details of what we are finalizing for the 
ample margin of safety analysis are in section IV.A.3. of this 
preamble. The details of what we are promulgating for the aisle 
scrubber source are in section IV.B.3.
    With the exception of the revised emissions described above, the 
risk assessment supporting the final rule was conducted in the same 
manner, using the same models and methods, as that conducted for the 
supplemental proposal. The documentation for the final rule risk 
assessment can be found in the memorandum titled Freeport Baseline and 
Control Options Re-model Risk Analysis Memo, which is available in the 
docket for this rulemaking.
Inhalation Risk Assessment Results.
    Table 3 presents the updated summary of the inhalation risk 
assessment results based on the updated modeling supporting the final 
rule. The results are very similar to those of the 2023 supplemental 
proposal. The only changes are to the number of people at increased 
risk of cancer greater than or equal to 1-in-1 million.
BILLING CODE 6560-50-P

[[Page 41661]]

[GRAPHIC] [TIFF OMITTED] TR13MY24.104

3. What key comments did we receive on the risk review, and what are 
our responses?
    We received comments regarding the risk assessment for the Primary 
Copper Smelting source category. The following is a summary of some of 
the more significant comments and our responses to those comments. 
Other comments received and our responses to those comments can be 
found in the document titled National Emission Standards for Hazardous 
Air Pollutant Emissions: Primary Copper Smelting Residual Risk and 
Technology Review and Primary Copper Smelting Area Source Technology 
Review: Summary of Public Comments and Responses, available in the 
docket for this action (Docket ID No. EPA-HQ-OAR-2020-0430).
    Comment: In response to the EPA's request for comment on our ample 
margin of safety analysis in the 2022 proposal, in which we discussed 
and sought comment on but decided not to propose additional controls 
for the aisle scrubber, specifically a WESP, one commenter stated that 
they agreed with our decision. The commenter suggested that the aisle 
scrubber should be subject to a concentration-based filterable 
particulate matter (fPM) limit of 23 mg/dscm similar to other vents 
processing emissions from the vessels managing

[[Page 41662]]

molten material, and that the existing MACT floor emissions from the 
aisle scrubber do not significantly contribute to the estimated risks 
from metal HAP. Other commenters supported our consideration of 
additional controls for the aisle scrubber. In the 2023 supplemental 
proposal, we discussed another ample margin of safety analysis in which 
we co-proposed two possible control options for the aisle scrubber, a 
WESP downstream of the aisle scrubber or a baghouse upstream of the 
aisle scrubber. One commenter expressed support for the additional 
controls on the aisle scrubber and for the associated reduction to 
risk. Several commenters stated the proposed options do not meet the 
requirements for ample margin of safety, which according to the 
commenters must be cost effective, feasible, and provide meaningful 
improvement in risk to public health. One of the commenters explained 
that the two metrics for evaluating risk reduction are based on the MIR 
cancer risk and the noncancer HQ. Concerning these control options, the 
commenters asserted the MIR is unchanged when reducing to significant 
digits and that it remains at 20-in-1 million after accounting for the 
associated reductions. One commenter noted that these MIR values 
consider expected reductions from other risk-based standards in the 
2022 proposal and 2023 supplemental proposal (e.g., the process 
fugitive roofline vent standard). One of the commenters took issue with 
the standard being applied only to the Freeport facility. The commenter 
contended that the roofline controls to achieve acceptable risk leave 
the MIR for the other major source copper smelter (Asarco) 
``untouched'' at 60-in-1 million, asserting that this is ``unfair, 
arbitrary and capricious, and unsupported by the record.'' While the 
EPA estimated the HQ would drop from 2 to 1 for both options in the 
2023 proposed rule, the commenter argued that the acute arsenic HQ 
value is based on a poorly documented and outdated study, and that more 
recent studies have failed to demonstrate the developmental impact 
which is at the foundation of the EPA's HQ assessment. The commenters 
added that the EPA has accepted much higher HQ values for arsenic in 
other rules (e.g., Integrated Iron and Steel Manufacturing NESHAP 85 FR 
42074, 42083; Primary Aluminum Reduction Plants NESHAP 80 FR 62390, 
62398). The commenters also noted that emission reductions were 
overestimated by the EPA and resulted in overstated reductions to risk.
    Response: The finding of unacceptable risks is not based on any one 
risk metric (e.g., acute hazard quotients), but rather considering all 
health information available and the degree of uncertainty associated 
with that information. In the 2015 final rule for Primary Aluminum 
(Docket ID No. EPA-HQ-OAR-2011-0797), EPA weighed all health risk 
factors and uncertainties in the risk acceptability determination for 
the Prebake ovens subcategory. The current acute methodology, while 
similar between the two rules, is still considered a screening 
assessment. While the chronic cancer risks for both source categories 
were comparable, the acute screening methodologies differ and must be 
weighted in regard to the accuracy and uncertainty of each piece of 
information in a weight-of-evidence approach for each decision. This 
relevant body of information is growing fast (and will likely continue 
to grow even faster), necessitating a flexible weight-of-evidence 
approach that acknowledges both complexity and uncertainty in the 
simplest and most transparent way possible. The acute screening risks 
posed by arsenic are based upon the most up to date review of the REL 
by EPA and considered the best available benchmark for assessing 
current risks posed by this pollutant. The application of the acute 
benchmarks when paired with our acute methodology to assess 
``reasonable worst-case one-hour concentrations (i.e., 99th 
percentile)'' for off-site locations where people maybe present 
provides a realistic estimate or screen for short-term exposures while 
we consider EPA's chronic assessment for this source category to be a 
refined site-specific assessment.
    Based on comments and information provided during the comment 
period, we have updated the estimated control efficiency for both 
options co-proposed in the 2023 supplemental proposal, and therefore 
the final rule expected emission reductions are less than those 
proposed in the 2023 supplemental proposal. We have taken this and all 
comments into consideration and determined that it is necessary to 
promulgate a PM emission limit for the combined emissions from the 
anode refining point source and the Hoboken converter process fugitive 
capture system pursuant to CAA section 112(d)(6) but not pursuant to 
CAA section 112(f)(2) because after further consideration and 
comparison to other source categories, in this specific case, we agree 
with the commenter that the risk reductions are minimal and that these 
controls are not necessary to ensure the NESHAP provides an ample 
margin of safety pursuant to CAA section 112(f). Given the space and 
infrastructure issues and challenges and effort needed to construct and 
operate such a new control system at Freeport, we conclude that the 
facility will likely need up to 3 years to demonstrate compliance with 
the new standards, which are described in more detail in section IV.B. 
of this preamble. Given the factors described above, we are finalizing 
Option 2, with a revised PM emission standard of 4.1 mg/dscm, under the 
CAA section 112(d)(6) technology review because we conclude that this 
option represents a development in technologies, processes or practices 
pursuant to section 112(d)(6). As described in more detail in section 
IV.B. of this preamble, the baghouse technology to reduce metal HAP 
emissions at the aisle scrubber identified in the 2023 supplemental 
proposal is feasible, readily available and already in use at primary 
copper smelting facilities (including Freeport) as well as in use at 
facilities in other source categories. We are allowing up to 3 years to 
comply with this standard because we conclude the facility will need up 
to 3 years to plan, design, install and operate new controls to reduce 
emissions from the aisle scrubber. The rationale for our decision to 
promulgate a standard under CAA 112(d)(6) is described further in 
section IV.B. of this preamble.
4. What is the rationale for our final approach and final decisions for 
the risk review?
    The EPA sets standards under CAA section 112(f)(2) using ``a two-
step standard-setting approach, with an analytical first step to 
determine an `acceptable risk' that considers all health information, 
including risk estimation uncertainty and includes a presumptive limit 
on MIR of approximately 1-in-10 thousand.\5\ If risks are unacceptable, 
the EPA must determine the emissions standards necessary to reduce risk 
to an acceptable level without considering costs. A second step follows 
in which the actual standard is set at a level that provides `an ample 
margin of safety' in consideration of all health information, including 
the number of persons at risk levels higher than approximately 1-in-1 
million, as well as other relevant factors including costs and economic 
impacts, technological feasibility, and other

[[Page 41663]]

factors relevant to each particular decision.'' As discussed in more 
detail in the 2022 proposal and in the Benzene NESHAP, there is 
flexibility regarding factors the EPA may consider in making 
determinations and how the EPA may weigh those factors for each source 
category. The EPA conducts a risk assessment that provides estimates of 
the MIR posed by emissions of HAP that are carcinogens from each source 
in the source category, the HI for chronic exposures to HAP with the 
potential to cause noncancer health effects, the HQ for acute exposures 
to HAP with the potential to cause noncancer health effects,\6\ and to 
assess risks for lead, the EPA compares ambient air concentrations with 
the lead NAAQS, which is 0.15 ug/m3 based on 3-month rolling averages. 
The assessment also provides estimates of the distribution of cancer 
risk within the exposed populations, cancer incidence, and an 
evaluation of the potential for an adverse environmental effect. (54 FR 
38045, September 14, 1989) As discussed in the 2022 proposed rule, the 
scope of the EPA's risk analysis is consistent with the explanation in 
EPA's response to comments on our policy under the Benzene NESHAP (54 
FR 38057) summarized hereafter: In summary, the EPA's policy permits 
consideration of multiple measures of health risk including, but not 
limited to, the MIR, the presence of non-cancer health effects, and the 
uncertainties of the risk estimates such that these factors can then be 
weighed in each individual case. The EPA's policy, as discussed in the 
Benzene NESHAP response to comments, also complies with the 
Congressional intent behind the CAA.
---------------------------------------------------------------------------

    \5\ 1-in-10 thousand is equivalent to 100-in-1 million. The EPA 
currently describes cancer risks as `n-in-1 million.'
    \6\ The MIR is defined as the cancer risk associated with a 
lifetime of exposure at the highest concentration of HAP where 
people are likely to live. The HQ is the ratio of the potential HAP 
exposure concentration to the noncancer dose-response value; the HI 
is the sum of HQs for HAP that affect the same target organ or organ 
system.
---------------------------------------------------------------------------

    Thus, the level of the MIR is only one factor to be weighed in 
determining acceptability of risk. The Benzene NESHAP explained that 
``an MIR of approximately one in 10 thousand should ordinarily be the 
upper end of the range of acceptability. As risks increase above this 
benchmark, they become presumptively less acceptable under CAA section 
112, and would be weighed with the other health risk measures and 
information in making an overall judgment on acceptability. Or, the 
Agency may find, in a particular case, that a risk that includes an MIR 
less than the presumptively acceptable level is unacceptable in the 
light of other health risk factors.'' Id. at 38045. In other words, 
risks that include an MIR above 100-in-1 million may be determined to 
be acceptable, and risks with an MIR below that level may be determined 
to be unacceptable, depending on all of the available health 
information.
a. Acceptability Determination
    In this final rule, as in the 2023 supplemental proposal and in the 
2022 proposal, the EPA concludes that the baseline risks are 
unacceptable. This determination, as described in the 2022 proposal and 
the 2023 supplemental proposal, is largely based on the estimated 
exceedance of the lead NAAQS, along with the maximum acute HQ of 7 for 
arsenic, which indicate there are significant risks of acute noncancer 
health effects--especially for children, infants, and developing 
fetuses, all of whom are particularly vulnerable to chemical exposures 
as they undergo key developmental processes. Also contributing to this 
determination, although to a lesser extent, are the inhalation cancer 
MIRs due to arsenic, with an estimated MIR of 70-in-1 million for 
actual emissions and 90-in-1 million for allowable emissions, which are 
approaching the presumptive level of unacceptability of 100-in-1 
million.
b. What is EPA requiring in the final rule to address the unacceptable 
risk?
    To address the unacceptable risk, the Agency is promulgating a 
combined PM emission limit (as a surrogate for HAP metals other than 
mercury) for process fugitive emissions from roofline vents of a 
combination of smelting vessels, copper converter departments, slag 
cleaning vessels and anode refining departments at new and existing 
sources as proposed in the 2023 supplemental proposal. We are also 
finalizing the PM emission standard pursuant to CAA section 112(d)(2) 
and (d)(3) as discussed further in section IV.C. of this preamble. We 
are also finalizing, as proposed, that compliance would be demonstrated 
through an initial performance test followed by a compliance test once 
per year.
c. Remaining Risks After Implementation of the Requirements To Address 
Unacceptable Risk
    To determine the remaining risks after implementation of the new 
combined PM emission limit to control process fugitive emissions from 
the roofline vents, we conducted a post-control risk assessment. As 
described in section IV.A.2., the baseline emissions for the aisle 
scrubber source at Freeport were corrected and the baseline modeling 
was conducted again for the final rule along with the roofline vents 
control option. The revised baseline modeling results, as discussed in 
section IV.A.2., did not result in any change to the acceptability 
determination or to the main risk driver under section 112(f) of the 
CAA. More details on the modeling for the final rule are in the 
memorandum Freeport Baseline and Control Options Re-model Risk Analysis 
Memo, found in the docket for this action. More details on the modeling 
analysis for the 2023 supplemental proposal are described in the 
document Revised Residual Risk Assessment for the Freeport Smelter 
(Miami, AZ) in Support of the 2023 Supplemental Proposal for the 
Primary Copper Smelting Source Category, available in the docket for 
this action (Docket ID No. EPA-HQ-OAR-2020-0430-0187).
    The post-control modeled risks were updated as described in the 
memorandum Freeport Baseline and Control Options Re-model Risk Analysis 
Memo, available in the docket for this rule (Docket ID No. EPA-HQ-OAR-
2020-0430). The risk assessment after implementing the PM limit for 
process fugitive emission from roof vents as discussed in this section 
of this preamble indicates that the modeled lead concentrations would 
be reduced to 0.06 [micro]g/m3, which is below the NAAQS of 0.15 
[micro]g/m3. The MIR at Freeport is reduced from 70-in-1 million to 20-
in-1 million and the population with cancer risks greater than or equal 
to 1-in-1 million is reduced from 21,875 to 16,035. We estimate that at 
Freeport the maximum chronic noncancer inhalation TOSHI will be reduced 
from 1 to less than 1 (0.3), and the acute HQ will be reduced from a 
value of 7 to 2. We estimate that the source category MIR after 
implementation of the PM limit for process fugitive emissions from 
roofline vents will be 60-in-1 million, which is the maximum baseline 
cancer risk near the Asarco facility. We expect that Asarco can comply 
with the PM standard for process fugitive emissions from roofline vents 
without additional controls, and therefore it will not achieve emission 
reductions at Asarco as a result of this PM limit. However, as 
described in sections III.B. and III.C., and IV.B. and IV.C. of this 
preamble, we are finalizing a lead limit under CAA sections 112(d)(2) 
and (3) and design standards under our CAA section 112(d)(6) technology 
review, respectively, that will achieve reductions of HAP metal 
emissions at Asarco. We note that the facility already has plans to 
implement improvements (consistent with the design standards in

[[Page 41664]]

this final rule) that will reduce their process fugitive emissions of 
metal HAP as well as SO2 emissions. In fact, these 
improvements have been adopted into their most recent state operating 
permit (finalized in October 2023). As mentioned elsewhere in this 
preamble, Asarco is currently not operating. However, we expect that 
these improvement projects will likely reduce the MIR when Asarco 
returns to operating status.
    Based on the post-control risk assessment, we conclude that, after 
the requirements described in this preamble to address unacceptable 
risk are implemented, the risks to public health will be reduced to an 
acceptable level.
d. Ample Margin of Safety Analysis
    Under the ample margin of safety analysis, we again considered all 
of the health factors evaluated in the acceptability determination and 
evaluated the cost and feasibility of available control technologies 
and other measures (including the controls, measures, and costs 
reviewed under the technology review) that could be applied to further 
reduce the risks due to emission of HAP identified in our risk 
assessment.
    While the additional controls for the combined gas stream from the 
anode refining department and the Hoboken converter process fugitive 
capture system identified under the technology review will provide some 
additional risk reduction, in this case the additional risk reduction 
is minimal (for example, no change in the cancer MIR of 20-in-1 
million), and therefore we are not finalizing this emission standard to 
provide an ample margin of safety. We conclude that the standards we 
are finalizing to achieve acceptable risk will also provide an ample 
margin of safety to protect public health and that, as proposed, a more 
stringent standard is not necessary to prevent an adverse environmental 
effect in accordance with CAA section 112(f)(2).

B. Technology Review for the Primary Copper Smelting Source Category

1. What did we propose pursuant to CAA section 112(d)(6) for the 
Primary Copper Smelting source category?
    In the 2022 proposal, as part of our ample margin of safety 
analysis and technology review, we considered additional controls for 
the Freeport aisle scrubber which was the second highest contributor to 
the baseline risks, estimated to represent 23 percent of the MIR. We 
estimated emission reductions and costs for controlling the combined 
emissions stream of the anode refining department and Hoboken converter 
process fugitive capture system (i.e., the aisle scrubber) with a WESP. 
We also estimated the impacts on risk reductions of these additional 
controls. The Agency sought comment on this control option but did not 
propose it in the 2022 proposal. We received comments on the control 
option for the aisle scrubber as well as additional information from 
the Freeport facility in response to the EPA's 2022 section 114 
information request.
    Subsequently, in the 2023 supplemental proposal, based on the 
comments on the 2022 proposal and the new information from the section 
114 information request, the EPA co-proposed regulatory options for 
additional control of either the Hoboken converter process fugitive 
capture system or additional control of the combined emissions stream 
of the Hoboken converter process fugitive capture system and the anode 
refining department (i.e., aisle scrubber). These standards were 
proposed as technology developments pursuant to CAA section 112(d)(6) 
and to provide an ample margin of safety to protect public health 
pursuant to CAA section 112(f)(2). As described in the 2023 
supplemental proposal, the first option (hereafter referred to as 
Option 1) was the addition of a WESP downstream of the aisle scrubber 
providing additional control of the combined emissions stream from the 
Hoboken converter process fugitive capture system and the anode 
refining department point source (i.e., the same option evaluated by 
the EPA in our ample margin of safety analysis included in the 2022 
proposal). The second option (hereafter referred to as Option 2) was 
the addition of a baghouse upstream of the aisle scrubber providing 
additional control of the Hoboken converter process fugitive capture 
system. As noted in the 2023 supplemental proposal, using performance 
test data from Freeport we estimated the baseline emissions for the 
aisle scrubber to be 6.63 tpy metal HAP. We also used these test data 
as the basis to establish an emissions limit along with an estimate of 
the expected reductions that would be achieved with the additional 
controls (i.e., a new baghouse up-stream of current Aisle scrubber or a 
WESP after the Aisle scrubber). To do this, we first used the data to 
develop the 99 percent upper prediction limit (UPL). The 99 percent UPL 
for the combined emissions stream from the anode refining department 
and the Hoboken converter process fugitive capture system is 7.48 mg/
dscm. This UPL served as the baseline for the development of the 
potential emission standards for each option. Secondly, the UPL value 
was adjusted (decreased) based on the expected percent reduction that 
would be achieved by each option. Finally, we estimated costs and risk 
reductions for each control option. A summary of the options as 
presented in the 2023 supplemental proposal is included here for 
reference. Because we proposed these standards under both the 
technology review authority of CAA section 112(d)(6) and the risk 
review authority of CAA section 112(f)(2), we estimated risk reductions 
associated with each of the options consistent with a CAA section 
112(f)(2) ample margin of safety analysis and our summary that follows 
includes those results even though the risk results would not typically 
be part of the analysis to support a CAA section 112(d)(6) technology 
review. The summary of the risk reductions presented are the 
incremental changes attributed to the control option after considering 
the effects of the implementation of the other risk-based standards in 
this rulemaking (i.e., the process fugitive roofline vent standards).
    For Option 1, we estimated that the control technology could 
achieve 95 percent emissions reduction which was estimated to be 6.3 
tpy metal HAP. The emission limit for this option was 0.374 mg/dscm. 
The estimated costs were $98.5 million capital costs, $25.2 million 
total annualized costs, and a cost effectiveness of $4.0 million/ton 
metal HAP. Risks would be reduced below 1-in-1 million for an 
additional 1,900 people (the number of people with risk greater than 1-
in-1 million would be reduced from 17,400 to 15,500). The maximum acute 
HQ due to arsenic emissions would be reduced from 2 to 1. The MIR at 
Freeport (20-in-1 million) and for the source category (60-in-1 
million) would be unchanged by this control option.
    For Option 2, we estimated that the control technology could 
achieve 90 percent reduction of the Hoboken converter process fugitive 
capture system emissions (or 68 percent reduction of the aisle scrubber 
emissions overall) which was estimated to be 4.5 tpy metal HAP. The 
emission limit for this option was 2.43 mg/dscm. The estimated costs 
were $37 million capital costs, $6.2 million total annualized costs, 
and a cost effectiveness of $1.38 million/ton metal HAP. Risks would be 
reduced below 1-in-1 million for an additional 700 people (the number 
of people with risk greater than 1-in-1 million would be reduced from 
17,400 to 16,700). The maximum acute HQ due to arsenic

[[Page 41665]]

emissions would be reduced from 2 to 1. The MIR at Freeport (20-in-1 
million) and for the source category (60-in-1 million) would be 
unchanged by this control option.
    The Agency also proposed, in the 2022 proposal, additional work 
practices to reduce fugitive dust emissions and development of a 
fugitive dust control plan that must be reviewed, updated (if 
necessary), and approved by the Administrator or delegated permitting 
authority. We proposed these requirements in order to provide an ample 
margin of safety under CAA section 112(f)(2) and as a development in 
practices pursuant to CAA section 112(d)(6).
    With regard to the emission sources at the area source primary 
copper smelting facility, including sources of fugitive dust emissions, 
the Agency did not identify any developments in practices, processes, 
or control technologies. For more details, refer to the document 
Technology Review for the Primary Copper Smelting Source Category, 
which is available in Docket ID No. EPA-HQ-OAR-2020-0430.
2. How did the technology review change for the Primary Copper Smelting 
major source category?
    Based on comments received during the comment period for the 2023 
supplemental proposal, as discussed in more detail in section IV.B.3. 
of this preamble, we revised our expected emission reductions and 
control costs for the aisle scrubber control options. A detailed 
description of the emission reduction estimates and cost estimates 
associated with these options is provided in the memorandum Cost 
Estimates for Additional Controls of Freeport's Aisle Scrubber--
REVISED, which is available in the docket for this rulemaking.
    Specifically, for Option 1, we now estimate the control efficiency 
as 73 percent and estimate emissions reductions of 4.9 tpy metal HAP. 
We did not amend our cost estimates for this option from those 
presented in the 2023 supplemental proposal. So, combining our revision 
to the estimated emission reductions with the costs presented in the 
2023 supplemental proposal yields a revised cost effectiveness value of 
$5.2 million/ton HAP metal. We received additional information from 
Freeport regarding the costs for site preparation well after the close 
of the public comment period in a letter dated January 29, 2024, which 
is available in the docket. In this letter, Freeport estimated costs to 
demolish and relocate part of the aisle scrubber motor control center 
(MCC) room, a parking and storage area, and part of the converter 
maintenance building in order to install a WESP. They estimated these 
site preparation costs to be $9.2M in capital. As noted above, we 
received this information about four months after the close of the 
comment period. Furthermore, the letter did not provide sufficient 
details to determine the validity of the estimate. Therefore we have 
not included it in our cost estimates. However, we note that if we did 
include these costs, the total capital costs would be $108M, the 
annualized costs would be $26M, and the cost effectiveness would be 
slightly higher at $5.4M/ton of HAP metal reduced.
    For Option 2, we now estimate the baghouse will achieve 61 percent 
control efficiency of the Hoboken converter process fugitive capture 
system gas stream and estimate emissions reductions of 3.0 tpy metal 
HAP (which represents an overall control efficiency of 46 percent for 
the aisle scrubber). We also revised our cost estimates for Option 2. 
The revised cost estimates provide a total capital investment of $59.5 
million, total annualized costs of $10.8 million and a cost 
effectiveness of $3.6 million/ton HAP metal. As noted above under 
Option 1, we received additional information from Freeport, well after 
the close of the comment period, regarding costs for site preparation 
in the area where a baghouse would be installed. They estimated it 
would cost $5.2M to demolish and relocate the anode baghouse MCC room, 
storage bunkers, and demolition and rerouting of the aisle scrubber 
piping that is currently located in the area where they estimate the 
baghouse would be installed. As stated under Option 1, we have not 
included this cost in our estimates because we received this 
information well after the close of the comment period and we have 
insufficient details to evaluate its validity. However, we note that if 
we did include their estimate for site preparation, the total capital 
investment would increase to $64.8M, with total annualized costs of 
$11.5M and a slightly higher cost effectiveness of $3.8M/ton HAP metal 
reduced.
    In addition, we received new information regarding the Asarco 
facility since publication of the 2023 supplemental proposal. Asarco is 
located in the Hayden area of Gila and Pinal Counties in Arizona and is 
the primary source of lead emissions in this area. As discussed in the 
2022 proposed rule, the Hayden area is currently designated as 
nonattainment for the 2010, 1-hour primary SO2 NAAQS and 
2008 lead NAAQS. There have been various regulatory actions to reduce 
emissions in this area and at the Asarco facility including, but not 
limited to, a consent decree between EPA and Asarco to bring the 
facility into compliance with the NESHAP by December 2018 and revisions 
to the state implementation plan (SIP) to help achieve attainment of 
the lead NAAQS by October 2019. However, effective March 2, 2022, the 
EPA determined that the Hayden lead nonattainment area failed to attain 
the 2008 lead primary and secondary lead NAAQS and the 2010 1-hour 
primary SO2 NAAQS (87 FR 4805, January 31, 2022) by the 
applicable date of October 3, 2019. As a result, the State of Arizona 
is required to submit revisions of the SIP to EPA. As part of this 
process, EPA Region 9 staff informed the EPA Office of Air Quality 
Planning and Standards staff in October 2023 of several projects that 
Asarco has planned as part of the most recent SIP revisions and that 
ADEQ has adopted into Appendix A of Asarco's operating permit (October 
3, 2023), which is available in the docket for this action. The 
projects include engineering controls and work practices which Asarco 
estimates will reduce fugitive metal HAP emissions at the facility. The 
projects that are in Asarco's operating permit include the following:
     Flash Furnace Control System: This project involves 
installing and ventilating a partial enclosure around the Inco flash 
furnace uptake shaft to improve the capture of process fugitives.
     Fuming Ladle Capture System: This project involves the 
construction of a hood and retaining walls to improve capture of 
process fugitives from fuming ladles.
     Anode Furnace Secondary Hood Capture and Control System: 
This project involves the construction of secondary hoods to improve 
capture and then ducts the emissions to a planned new anode secondary 
hood baghouse.
    These projects will help ensure that process fugitive metal HAP 
roofline emissions would be reduced and will ensure that the roofline 
emissions at Asarco can meet a lead limit of 0.326 lb/hour, which is 
based on modeling demonstration submitted by the facility to the state 
in support of a revision to the lead SIP. We expect no additional costs 
to comply with the lead limit other than compliance testing costs. The 
lead limit is further discussed in section IV.C.2.

[[Page 41666]]

3. What key comments did we receive on the technology review, and what 
are our responses?
    Comment: Commenters objected to the EPA's change in position in the 
supplemental proposal about using a WESP to control aisle scrubber 
emissions. The commenters stated that the EPA rejected the technology 
in the 2022 proposal yet co-proposed it as an option in the 2023 
supplemental proposal. Commenters stated that in the 2022 proposal, the 
EPA concluded with regards to using a WESP to control aisle scrubber 
emissions that ``[g]iven the relatively high estimated capital costs, 
uncertainties, and moderate risk reductions . . . the Agency is not 
proposing these additional controls'' under the ample margin of safety 
analysis. Yet in the supplemental proposal the EPA stated the ``cost 
impacts'' of $4.0 million/ton metal HAP for a WESP are ``reasonable.'' 
The commenters point out the new cost effectiveness in the supplemental 
is more than 2 times the cost effectiveness that the EPA considered 
excessive for a WESP in the 2022 proposal, and that it far exceeds the 
precedent set in the recent Coke Oven proposed NESHAP revisions, where 
the agency found that $1.3 million/ton is the reasonable upper 
threshold of cost effectiveness for nonmercury metal HAP.
    In addition to objecting to the EPA's change of position on using a 
WESP, another commenter stated that the EPA overestimated the 
achievable removal efficiency for a WESP in the dilute, high volume gas 
stream at the aisle scrubber. The commenter asserted that the actual 
removal efficiency would be 60 percent, rather than the 95 percent 
estimated by the EPA. The commenter performed their own estimate of 
emission reductions and cost and estimated a cost effectiveness of $6.3 
million/ton HAP metal. Other commenters expressed support for using a 
WESP to control aisle scrubber emissions as it would reduce metal 
emissions from the converter department and the anode refining 
department. The commenter stated that while the EPA does not express a 
preference for either the WESP or baghouse option, the WESP-based limit 
is consistent with the Clean Air Act, while the baghouse-based limit is 
not. Clean Air Act section 112(d)(2) expressly provides that the EPA's 
air toxics standards must require the ``maximum'' reduction that is 
``achievable'' considering cost and other statutory factors. As such, 
both proposed limits are achievable considering cost and other 
statutory factors, however, the ``maximum'' degree of reduction that is 
achievable is the one provided by the WESP-based limit. The commenter 
also noted the WESP-based limit would yield substantially greater 
reductions in metal HAP emissions (6.3 tpy as opposed to 4.5 tpy from 
the baghouse-based limit) and would reduce cancer risk below 1-in-1 
million for 1,900 people, whereas the baghouse-based limit would reduce 
cancer risk below 1-in-1 million for only 700 people. Another commenter 
added that emissions from smelters are virtually certain to increase in 
the future as the demand for copper increases, which means that the 
difference in reductions in using a WESP versus a baghouse will also 
increase. The commenter stated that the cost effectiveness ``of the 
WESP option will increase relative to the baghouse option, therefore, 
the EPA should issue a strong limit based on the reductions that are 
achievable with a WESP.'' Several commenters stated that the San Carlos 
Apache Tribe is directly impacted by both major source smelters, and 
emissions of lead and arsenic are of particular concern due to their 
persistent and bioaccumulative nature. The same commenters stated their 
support for the WESP option to achieve maximum emission reductions. 
These commenters also claimed that EPA underestimated the emissions of 
lead and other pollutants from the copper smelters based on a 
comparison to Toxics Release Inventory (TRI) data. One commenter 
provided TRI estimates for lead from the Freeport smelter, stating ``In 
2020, for example, the Freeport smelter alone reported emitting more 
than 14 tons of lead. In 2019, it reported emitting 21 tons of lead 
and, in 2018, it reported emitting more than 29 tons of lead . . .''.
    Response: In the 2022 proposal, we stated that we were not 
proposing the WESP control option at that time, however we solicited 
comments regarding our analysis and whether we should establish more 
stringent standards to reduce HAP metal emissions from the aisle 
scrubber. We also subsequently requested in a 2022 section 114 
information request that the Freeport facility perform feasibility 
analyses for additional control of the aisle scrubber. In response to 
the 2022 proposal, we received comment that we should establish more 
stringent standards to reduce HAP metal from the aisle scrubber. 
Therefore, we used the new information collected during the comment 
period and from Freeport's response to the CAA section 114 information 
request to develop the WESP and baghouse options presented in the 2023 
supplemental proposal.
    Based on comments we received on the 2023 supplemental proposal, we 
also revised our emission reductions estimates for the WESP. As 
described in the 2023 supplemental proposal, the expected control 
efficiency for the WESP was 95 percent, however, we acknowledge that a 
number of factors can affect control efficiency, including the 
particulate concentration of the inlet stream to the control device. 
The aisle scrubber handles a high volume of gas (flowrate of 
approximately 1 million actual cubic feet per minute) and low 
particulate loading relative to the flowrate. We agree with commenters 
that the low concentration of particulate in the exhaust stream of the 
aisle scrubber, which would be the inlet to the WESP, may present 
technical feasibility issues in achieving a 95 percent reduction. 
Therefore, we updated our estimates of emission reductions. As detailed 
in the technical memorandum Cost Estimates for Additional Controls of 
Freeport's Aisle Scrubber--REVISED, which is available in the docket 
for this rulemaking, we back-calculated the control efficiency of the 
WESP by assuming the aisle scrubber exhaust particulate would be 
reduced to 1 milligram per cubic meter (mg/m3) by the WESP, 
which is an assumed minimum outlet concentration for this control 
technology. Based on this back-calculation, the resulting control 
efficiency of the WESP is 73 percent. Applying this revised control 
efficiency to the baseline emissions for the aisle scrubber (6.63 tpy 
metal HAP) yields an estimated reduction of 4.9 tpy metal HAP. We did 
not receive information during the 2023 supplemental proposal comment 
period on our total annualized costs for the WESP option. Therefore, 
when we combine the revised emission reductions (4.9 tpy metal HAP) 
with the total annualized costs ($25.2 million) presented in the 2023 
supplemental proposal for the WESP option, the cost effectiveness is 
$5.2 million/ton HAP metal.
    As described in this final rule preamble, we have concluded that, 
after taking public comment into consideration and making the 
appropriate revisions to our estimates, the costs for Option 1 are not 
reasonable. For this reason and others discussed in this preamble, we 
are not promulgating the WESP option.
    In regard to comments on Tribal impacts and their concerns about 
lead and arsenic, the EPA recognizes the concerns of Tribal commenters 
and their representatives and we have taken their

[[Page 41667]]

comments into consideration in this action. With regard to impacts, 
although the EPA determined that risks due to HAP emissions are 
unacceptable at baseline for populations living close to the Freeport 
facility, the EPA's risk assessment completed for this source category 
indicates that health risks due to HAP emissions from primary copper 
smelting sources on Tribal lands, which are further away (about 10 
miles from the facility) are well within acceptability at baseline. 
After the amendments in this final rule are implemented, the NESHAP 
will provide an ample margin of safety for all populations, including 
the San Carlos Apache Tribe. More information regarding the estimated 
health risks due to lead and arsenic emissions to humans at baseline 
(due to current emissions) and post-control (due to emissions after the 
amendments in this action are implemented) are described in sections 
III.A. and IV.A. of this preamble, and the estimated impacts to various 
demographic groups are described in section V.F. of this preamble. More 
details of the risk assessment are available in the document titled 
Residual Risk Assessment for the Primary Copper Smelting Major Source 
Category in Support of the 2021 Risk and Technology Review Proposed 
Rule, which is available in the docket.
    Regarding the comments supporting the addition of WESP to control 
HAP metal emissions, for the reasons described elsewhere in this 
preamble, we are not promulgating the WESP option and are promulgating 
the baghouse option for the aisle scrubber. We estimate that the 
amendments in the final rule will reduce total metal HAP emissions 
(primarily lead and arsenic) by 8 tpy for the major source category.
    Regarding the TRI emissions estimates provided by the commenter 
compared to our estimates, we estimate that the two major source 
facilities currently emit a total of 16.7 tpy of metal HAP (the 
majority of these emissions are from Freeport). We estimated these 
emissions primarily using test data provided by the facility for the 
sources subject to the Primary Copper Smelting major source NESHAP. The 
TRI is a ``whole facility'' inventory, which means that it includes 
estimates of stack and fugitive air emissions for all HAPs that are 
emitted at the facility which also include emissions from non-source 
category processes. Our emission estimates include those applicable to 
the primary copper smelting source category only. However, as noted in 
previous paragraph, this final rule will achieve an estimated reduction 
of 8 tpy of HAP metals, therefore after these amendments to the NESHAP 
are implemented, total estimated emissions will be about 8.7 tpy for 
the major source category.
    Comment: Commenters stated that the EPA erroneously describes their 
facility's converters as having ``primary and secondary capture systems 
and controls, but no tertiary controls.'' According to the commenter, 
Hoboken converters use a side-flue intake capture system, and the 
roofline canopy system (installed in 2017 as part of facility-wide 
improvements to ensure the Miami area's compliance with revised 
standards for SO2) is properly described as a tertiary 
capture system. Therefore, the commenter noted that the proposed 
standards would not appropriately apply to the converters at their 
facility as they do not have ``secondary capture systems.''
    Response: We have corrected the characterization of the capture and 
control systems for converters at the Freeport facility in the preamble 
and regulatory text associated with the final rule.
    Comment: Several commenters asserted that the aisle scrubber 
standards are not justified pursuant to section 112(d)(6). The 
commenters argued that the EPA has not identified any ``developments in 
practice, processes or control technologies'' since the original 
publication of the Primary Copper Smelting NESHAP that would justify 
additional controls on the aisle scrubber. Commenters noted that the 
EPA cites section 112(d)(6) to claim that ``developments'' warrant the 
imposition of new controls, but the EPA fails to recognize that section 
112(d)(6) only authorizes revisions that are ``necessary.'' The 
commenter asserted the word ``necessary'' cannot be ignored, and that 
it clearly requires some showing of necessity beyond the identification 
of ``developments'' because the mere existence of a development does 
not make it ``necessary.'' According to commenters, the fact that the 
term ``developments'' is found only in a parenthetical confirms it is 
merely one component of the analysis that ultimately must conclude a 
revision to a standard is ``necessary,'' a showing that the EPA has not 
made here.
    Response: We disagree that, in this case, additional controls to 
reduce emissions at the aisle scrubber are not necessary. The aisle 
scrubber stack was identified in the 2022 proposal as one of the 
largest sources of metal HAP emissions at Freeport. We currently 
estimate it emits 6.63 tpy of HAP metals (primarily lead and arsenic). 
The aisle scrubber is a control device that is mainly used to control 
SO2 emissions. This device controls emissions from the anode 
refining point source and emissions from the Hoboken converter process 
fugitive capture system. The anode refining point source gas stream 
passes through a PM control device (i.e., a baghouse) before entering 
the aisle scrubber for SO2 control, but the converter 
process fugitive capture system is ducted directly to the aisle 
scrubber without PM control prior to the aisle scrubber. We identified 
and proposed in the 2023 supplemental proposal 2 options to reduce 
metal HAP emissions from the aisle scrubber stack at Freeport. Our 
analysis shows that the technologies to reduce metal HAP emissions at 
the aisle scrubber identified in the 2023 supplemental proposal are 
readily available and already in use at primary copper smelting 
facilities (including Freeport) as well as in use at facilities in 
other source categories. This is especially true for baghouses. 
Regarding the WESP, although this technology has been applied at some 
emissions points at these facilities and other metals sectors (e.g., 
Secondary Lead Smelters), we are not aware of the WESP being 
successfully applied to emissions sources similar to the aisle 
scrubber. Specifically, the aisle scrubber has a very high flow rate 
and low concentration of PM compared to other point source emissions 
sources where the WESP has been applied.
    Another factor we considered in our decision is that the Asarco 
facility has a secondary hood capture system to collect secondary 
emissions from their Peirce-Smith converters and that secondary hood 
capture system is vented to a baghouse for PM control (which also 
controls metal HAP emissions). We find these PM controls are especially 
important for lead and arsenic because these two pollutants are 
persistent, bioaccumulative and highly toxic HAPs.
    Given all of this information, we conclude that additional PM 
controls are necessary to further reduce metal HAP at the aisle 
scrubber source, and that the baghouse technology that we proposed in 
the 2023 supplemental proposal (i.e., Option 2 in the supplemental 
proposed rule) represents a development that will further reduce metal 
HAP emissions at Freeport. The baghouse is a common, well demonstrated 
technology used to control PM emissions from various industrial 
emissions sources.
    Comment: One commenter was supportive of the baghouse option 
despite expressing a preference for the WESP option.

[[Page 41668]]

    Other commenters were opposed to the baghouse option. These 
commenters noted that the cost effectiveness of this option exceeds the 
threshold for cost effectiveness for nonmercury metal HAP despite being 
underestimated. Commenters stated that the EPA overstated emission 
reductions and underestimated costs by about a factor of 2.
    Commenters asserted that the EPA overstated the emission reductions 
from this option. One commenter explained that due to the high volume 
of the exhaust stream and the low particulate concentration in the 
exhaust stream (estimated to be on the order of 0.001 gr/ft\3\), 
control efficiency is expected to be closer to 50 percent, rather than 
the 90 percent used by the EPA. The commenter explained this is because 
they are not aware of any vendor guarantee of a minimum exhaust 
concentration of 0.0001 gr/ft\3\ which would be required to achieve 90 
percent control.
    Commenters provided their own estimate of the baghouse costs of 
$70-88 million and noted that the discrepancy between their estimate 
and the EPA's estimate in the supplemental proposal (which differed by 
about a factor of 2) can be attributed to: under sizing and, thus, 
underestimating costs for ductwork; using a shaker instead of more 
modern pulse jet style baghouse; using too small of a scaling factor to 
size the baghouse; underestimating the cost of the lime injection 
system; omitting indirect costs (e.g., freight, spare parts, 
engineering procurement and construction management services, equipment 
rental); and omitting contingency which the commenter included at a 
value of 25 percent. Using their own emission reduction estimates of 
2.5 tpy HAP metal and total annualized cost estimates ranging from 
$12.7M to $14.5M (with 25 percent contingency included), commenters 
estimated the cost effectiveness value for this option as being between 
$4.8 to $5.8 million/ton HAP.
    Response: As described in the previous comment response, we 
conclude that additional PM controls are necessary to further reduce 
metal HAP at the aisle scrubber source, and that the baghouse 
technology represents a development that will further reduce metal HAP 
emissions at Freeport. To inform our decision under the technology 
review, we evaluated the types of technology used in the industry and 
other source categories. We found that baghouse technology is readily 
available, feasible, well demonstrated and is being used to control a 
similar source at the other major source primary copper smelter in this 
source category. However, we have revised our emission reductions 
estimates and our cost estimates for this option after considering the 
comments.
    As described in the 2023 supplemental proposal, for a baghouse we 
generally expect achievable control efficiencies to be at least 90 
percent. We acknowledge that a number of factors can affect the control 
efficiency, including the particulate concentration of the inlet stream 
to the control device. Based on the engineering evaluation provided by 
Freeport in their 2022 section 114 information collection request 
response, the Hoboken converter process fugitive capture system has a 
high flowrate and low particulate loading relative to the flowrate. We 
agree with commenters that the expected concentration of particulate in 
the inlet stream may present technical feasibility issues achieving a 
90 percent reduction. Therefore, we updated our estimates of emission 
reductions.
    First, we note that through CAA section 114 information requests 
for other EPA rules (e.g., electric arc furnaces (EAF), foundries), we 
have collected data demonstrating that baghouses achieve average 
particulate outlet concentrations below 0.001 grains per dry standard 
cubic feet (gr/dscf). We found that baghouses with similar flowrates to 
those expected for the Hoboken process fugitive capture system in the 
EAF source category achieve, on average, outlet concentrations of 
filterable particulate of 0.0006 gr/dscf with a range of 0.0001 to 
0.0017 gr/dscf. For foundries, there were 2 facilities that were used 
to set the new source standard which had average PM emissions of 0.0002 
gr/dscf and a high value of 0.0004 gr/dscf. The other had an average of 
0.0008 gr/dscf and a high value of 0.00086 gr/dscf. Considering this 
information and the information provided in Freeport's engineering 
evaluation for the Hoboken converter process fugitive capture system, 
we back-calculated the control efficiency of the baghouse assuming that 
the Hoboken converter process fugitive capture system particulate would 
be reduced to 0.0005 gr/dscf which is an assumed achievable outlet 
concentration for this control option when estimating the control 
efficiency. The expected baghouse flowrate was taken from the Freeport 
engineering analysis, and the particulate loading was assumed to be 75 
percent of the aisle scrubber outlet. The resulting control efficiency 
is 61 percent. Applying this revised control efficiency to the baseline 
emissions for the Hoboken converter process fugitive capture system 
(assumed to be 75 percent of the aisle scrubber or 4.97 tpy metal HAP) 
yields an estimated reduction of 3.0 tpy metal HAP. The expected 
reduction is 46 percent of the aisle scrubber emissions overall, after 
the Hoboken converter process fugitive capture system baghouse stream 
combines with the controlled anode refining department stream in the 
aisle scrubber.
    Next, concerning costs, we have updated our cost estimates after 
considering the comments. We revised the estimated costs for total 
capital investment to include those costs provided by the commenter for 
equipment supply. We utilized the EPA cost control manual to estimate 
all indirect costs including contingency in accordance with section 6, 
Chapter 1--Baghouses and Filters. The revised cost estimates provide a 
total capital investment of $59.5 million and total annualized costs of 
$10.8 million. Using our emission reduction estimate and the total 
annualized cost estimate, the cost effectiveness is $3.6 million/ton 
metal HAP reduced.
    While this cost effectiveness is higher than we have accepted in 
the past for reducing metal HAP in some standards, there are other 
relevant factors that EPA can consider, and has considered. The highest 
cost effectiveness accepted in the past was $1.5M/ton of metal HAP in 
2009 dollars (which is about $2M/ton of metal HAP in 2022 dollars) in 
the Secondary Lead Smelting NESHAP (77 FR 556, January 5, 2012). 
However, it is important to note that EPA considers other factors 
besides cost-effectiveness when considering requirements under the 
technology reviews, such as feasibility of controls, how well certain 
controls have been demonstrated, and overall economic impacts. In this 
case, as described previously in this section, we determined that 
baghouse technology is readily available, feasible, well demonstrated 
and is being used to control a similar source at the other major source 
primary copper smelter in this source category. Furthermore, in this 
specific case, we have collectively considered the significant emission 
reductions of persistent, bioaccumulative, and toxic (PBT) HAPs 
(primarily lead and arsenic, which are both PBT HAPs), non-air 
environmental impacts, feasibility concerns, and the costs of each of 
the options. We note that lead and arsenic are known developmental 
toxicants that can cause particular harm to infants, children, and the 
developing fetus. Furthermore, arsenic is classified as a human 
carcinogen by the EPA and the World Health Organization. In addition, 
we do

[[Page 41669]]

not expect that the overall economic impacts of this rule will lead to 
significant changes in domestic copper production; the market price for 
commercial grade copper or any products comprised of copper inputs; or 
employment, as described in section V.D. of this preamble. This 
rationale and these considerations are discussed in more detail in 
section IV.B.4. of this preamble.
    The details of our emission reduction estimates and cost estimates 
have been provided in the technical memorandum Cost Estimates for 
Additional Controls of Freeport's Aisle Scrubber--REVISED, which is 
available in the docket for this rulemaking.
4. What is the rationale for our final approach for the technology 
review?
    As noted in section IV.A. of this preamble, we updated our risk 
modeling based on the revisions to the expected emission reductions for 
each of the options proposed in the 2023 supplemental proposal. We 
conclude that, in this case, the risk reductions achieved are not 
sufficient to promulgate this standard (i.e., the PM limit for the 
Aisle scrubber described previously in this section) pursuant to CAA 
section 112(f); however, we continue to maintain that baghouses are 
proven technologies for achieving high degrees of particulate control. 
We also find that additional controls on similar exhaust streams are 
used in the source category. As discussed in section IV.B.3. of this 
preamble, the aisle scrubber stack is one of the largest sources of 
metal HAP emissions at Freeport. We estimate it emits 6.63 tpy of HAP 
metals (primarily lead and arsenic). The aisle scrubber is a control 
device that is mainly used to control SO2 emissions from the 
anode refining point source and from the Hoboken converter process 
fugitive capture system. While the anode refining point source gases 
are vented to a PM control device before entering the aisle scrubber, 
the gas stream from the Hoboken converter process fugitive capture 
system vents directly to the aisle scrubber without prior PM control. 
We conclude that further reduction of metal HAP emissions from the 
aisle scrubber are necessary and that there are developments in 
practices, processes, or control technologies that will achieve further 
reductions of metal HAP emissions at Freeport. The PM controls on this 
source are especially important for reducing lead and arsenic because 
these two pollutants are PBT HAPs.
    To inform our decision under the technology review, we evaluated 
the types of technology used in the industry and in other source 
categories to control PM emissions. As discussed in this preamble, we 
proposed two options in the 2023 supplemental proposal: Option 1 
evaluated a tighter PM limit based on the application of a WESP 
downstream of the aisle scrubber and Option 2 evaluated a tighter PM 
limit based on using baghouse technology upstream of the aisle 
scrubber. We next analyzed the technical feasibility, estimated costs, 
and non-air environmental impacts for each option. As described in 
section IV.B.3. of this preamble, we are not aware of a WESP (Option 1) 
being successfully applied to emissions sources similar to the aisle 
scrubber, which has a very high flow rate and low concentration of PM 
compared to other point source emissions sources where the WESP has 
been applied. As described previously in this preamble, we determined 
that baghouse technology (Option 2) is readily available, feasible, and 
is being used to control a similar source at the other major source 
copper smelter in this source category.
    With regard to feasibility, the Freeport facility property does not 
extend far beyond its core manufacturing operations and is bordered on 
one side by a railroad track; therefore, space to install large 
equipment such as that required in either option is limited. In their 
feasibility analysis for these control options, Freeport explained that 
Option 1 requires a larger footprint than Option 2. We also considered 
the secondary impacts of the two control options and found that Option 
1 would require the use of significant amounts of water, which is of 
particular concern because the facility is located in an arid climate 
where water resources are limited.
    As is permitted under CAA section 112(d)(6), we also considered the 
costs of each option. The cost estimates for the WESP option include a 
total capital investment of $98.5M and total annualized costs of 
$25.2M. With an estimated reduction of 4.9 tpy of total metal HAP 
emissions, we estimate the cost effectiveness of installing a WESP is 
$5.2M/ton of HAP metal reduced. We have updated our cost and emission 
reduction estimates for the baghouse option after considering the 
comments as described in section IV.B.3. The revised cost estimates 
include a total capital investment of $59.5 million and total 
annualized costs of $10.8 million. Using our emission reduction 
estimate of 3.0 tpy and the total annualized cost estimate, the cost 
effectiveness is $3.6 million/ton metal HAP reduced for the baghouse 
option (Option 2).
    In collectively considering the emission reductions, secondary 
impacts, feasibility concerns, and the costs of each of the options, we 
find that Option 2 provides sizeable reductions of HAP metals, 
including two highly toxic persistent bioaccumulative HAPs (i.e., lead 
and arsenic) at reasonable costs while minimizing secondary impacts and 
feasibility concerns. Therefore, taking into consideration the comments 
and other information and data as well as the other factors discussed 
in this preamble, we are promulgating a PM standard of 4.1 mg/dscm for 
the combined emissions stream from the Hoboken converter process 
fugitive capture system and the anode refining department (i.e., the 
aisle scrubber) pursuant to CAA section 112(d)(6). We estimate this 
will reduce HAP metal emissions by 3.0 tpy.
    A detailed description on the development of this emission standard 
is provided in the memorandum Final Emission Standard Development for 
the Aisle Scrubber, which is available in the docket for this 
rulemaking.
    In the 2022 proposal, additional work practice standards to 
minimize fugitive dust and development of a fugitive dust control plan 
that must be reviewed, updated (if necessary), and approved by the 
Administrator or delegated permitting authority were proposed. These 
standards were proposed in order to provide an ample margin of safety 
to protect public health and pursuant to CAA section 112(d)(6). In this 
specific case, for the Primary Copper Smelting source category, we have 
decided to promulgate the additional work practices to minimize 
fugitive dust and the development of a fugitive dust control plan under 
only the technology review. The work practices and dust plan 
requirements are the same as proposed in the 2022 proposal. The 
fugitive dust plan and work practices are appropriate under CAA section 
112(d)(6) because they are practices that will ensure emissions will be 
minimized. It is our understanding that the facilities are already 
doing these types of practices so, although these measures are 
anticipated to further address fugitive emissions and advance the goal 
of minimizing HAP metal emissions, we are unable to quantify and assure 
significant enough reductions in actual emissions that would 
significantly reduce health risk; therefore, we are not promulgating 
under CAA 112(f) in this particular case. We expect that since 
facilities are already implementing most of the additional work 
practices as part of requirements in the facility's operating permit or 
to comply with consent

[[Page 41670]]

decree, there will be minimal additional costs to comply with the final 
rule work practices and fugitive dust plan requirements. The only 
additional costs would be a slight increase related to recordkeeping 
and reporting requirements. For details on the work practices see the 
2022 proposal preamble (87 FR 1616).
    As noted in section IV.A.3., one of the commenters took issue with 
the aisle scrubber standard being applied only to the Freeport facility 
when their post-roofline control MIR is 20-in-1 million. They stated 
that roofline controls to achieve acceptable risk leave the MIR for the 
other major source copper smelter (Asarco) ``untouched'' at 60-in-1 
million, asserting this is ``unfair, arbitrary and capricious, and 
unsupported by the record.'' After considering this comment, our prior 
proposals, and the information in the record, we evaluated options 
under CAA section 112(d)(6) and 112(d)(2) and (3) to reduce process 
fugitive emissions from Asarco. In the 2022 proposal, we solicited 
comment on a BTF limit to control process fugitives from the flash 
furnace roofline vent to reduce risk at Asarco. We estimated that to 
comply with a BTF limit, the facility would need to install improved 
capture and control of the flash furnaces as well as the large ladle 
containing hot liquid matte from the flash furnace taping/pouring 
operations, called the fuming ladle. In our cost estimates, we assumed 
a new baghouse would be needed as well as a roofline ventilation 
capture system. We did not receive comments on this specific BTF 
standard or our cost estimation. However, as noted above in this 
paragraph, we did receive the general comment that said our proposal 
would do nothing to reduce the MIR of 60-in-1 million at Asarco.
    Nevertheless, as described in section IV.B.2., we received new 
information regarding developments in technology (3 projects to reduce 
process fugitive emissions from roof vents) currently planned for the 
Asarco facility (and have been incorporated into their state permit and 
draft SIP), which are estimated to achieve a 30 percent reduction in 
process fugitive metal HAP emissions from the roofline vents. We have 
reviewed this information and agree that these developments will reduce 
fugitive metal HAP emissions. We estimate, based on the roofline vent 
metal HAP emissions estimates we had for the 2022 proposal and applying 
a 30 percent reduction, that the total process fugitive metal HAP 
emissions (including lead and arsenic, which are persistent, 
bioaccumulative HAPs) from the roofline will be reduced by 0.39 tpy. 
These estimates are available in the docket for this action (see 
memorandum Cost Estimates for Enhanced Capture and Control of Process 
Fugitive Emissions at Asarco). We expect that the reductions in process 
fugitive metal HAP emissions will also reduce risk; however, we have 
not yet quantified this risk reduction because the facility is not 
currently operating and their future operational emission profile may 
be different than what we have modeled in support of the 2022 proposed 
rule. Furthermore, we received this information regarding the three 
projects well after the end of the comment period and therefore we did 
not have sufficient time to remodel and calculate the risk reductions 
that will be achieved.
    With regard to cost impacts, we estimate that for the facility to 
comply with these design standards (and comply with the lead limit, 
promulgated under CAA section 112(d)(2) and (3), which is discussed in 
section IV.C.2. of this preamble), the facility will need to install 
improved capture and control consistent with what is expected under the 
state permit and SIP. As mentioned in section IV.B. of this preamble, 
the improvements needed to comply with the design standards and 
emissions limit are already adopted into the facility's operating 
permit and therefore costs impacts are already expected regardless of 
the requirements we are including in this final rule. However, since 
the facility has not yet begun construction for these improvements, we 
estimated costs for these projects as part of this action. We estimate 
that the total costs for complying with the design standards and lead 
emission limit are $15.4M in capital costs and $3.9M in annualized 
costs. Asarco provided estimated costs for these projects in a letter 
provided on February 26, 2024, which is available in the docket for 
this action. They estimate total capital costs of $22.4M and $5.8M in 
annualized costs for all three projects. Given the late submittal and 
the court-ordered promulgation deadline of May 2, 2024, we did not have 
sufficient time to review these estimates and determine their validity. 
However, we note again that the projects are already requirements in 
their operating permit and the facility is already expecting to incur 
these costs unrelated to the NESHAP. More details on the estimated 
costs are found in the memorandum Cost Estimates for Enhanced Capture 
and Control of Process Fugitive Emissions at Asarco, which is available 
in the docket for this action. To achieve reduction of HAP metals at 
Asarco, we are finalizing design standards consistent with their 2023 
operating permit which include improved capture and control of the 
Peirce-Smith flash furnaces, fuming ladles, and anode furnaces.

C. CAA Sections 112(d)(2) and (3) Revisions for the Primary Copper 
Smelting Source Category

1. Anode Refining Point Source Emissions
a. What did we propose for the anode refining point source pursuant to 
CAA section 112(d)(2) and (d)(3)?
    We proposed a MACT floor PM limit as a surrogate for metal HAP in 
40 CFR 63.1444(i) (finalized at 40 CFR 63.1444(f)) for new and existing 
anode refining departments in the 2022 proposal. The MACT floor 
emissions standard for new and existing sources, 5.78 mg/dscm, was 
developed based on the 99 percent UPL for PM emissions from the 
available emissions data (which was from Asarco) and represents the 
MACT floor level of control. We considered beyond-the-floor options for 
the standard, but we did not identify any feasible, cost-effective 
beyond-the-floor options. It should be noted that at the Freeport 
facility, the anode refining department gas stream and the Hoboken 
converter process fugitive capture system exhaust stream are both 
routed to and combined in the aisle scrubber from which they are 
emitted to the atmosphere. The facility conducts performance tests 
after the anode refining department stream is combined with the Hoboken 
converter process fugitive capture system exhaust stream (i.e., at the 
aisle scrubber outlet). Therefore, the EPA also proposed amendments to 
the existing alternative emission limit in 40 CFR 63.1446 to include 
the anode refining department stream, as we expected Freeport would be 
able to use this option to demonstrate compliance with the anode 
refining department emission limit at the aisle scrubber outlet. 
Lastly, we proposed in 40 CFR 63.1451(a) and 63.1453(a), respectively, 
that compliance with the PM emissions limit for the anode refining 
department will be demonstrated through an initial performance test 
followed by a compliance test at least once per year.
b. How did the anode refining point source revisions made pursuant to 
CAA section 112(d)(2) and (3) change since proposal?
    There are no changes to the emission standard for the anode 
refining point source since the proposals, except that we rounded the 
5.78 mg/dscm to 2

[[Page 41671]]

significant figures (i.e., 5.8 mg/dscm). We are promulgating the MACT 
floor-based PM emission standard of 5.8 mg/dscm for the anode refining 
department point source emissions (i.e., emissions exiting the anode 
baghouse) and related compliance requirements, as proposed in the 2022 
proposal. However, because Freeport combines their anode refining point 
source emissions with the fugitive capture system from the Hoboken 
converters, we are also finalizing, as proposed, to include the anode 
refining department point source emissions as an emission source to be 
included in the alternative emission limit calculation for the combined 
stream.
    Additionally, in the final rule based on comments, we are also 
providing that facilities that combine the anode refining department 
and Hoboken converter process fugitive capture system streams must 
comply with the combined stream PM limit of 4.1 mg/dscm and related 
compliance requirements to demonstrate compliance with the anode 
refining department emission standard and related compliance 
requirements. As discussed in section IV.B. of this preamble and 
pursuant to CAA section 112 (d)(6), we are finalizing a PM emission 
standard of 4.1 mg/dscm for the combined stream of the anode refining 
department and Hoboken converter process fugitive capture system and an 
annual compliance testing requirement.
c. What key comments did we receive on the proposed anode refining 
point source revisions made pursuant to CAA section 112(d)(2) and (3) 
and what are our responses?
    Comment: One commenter stated that the EPA should set the PM MACT 
floor based on a concentration limit of 23 mg/dscm, which is an 
existing technology-based limit for similar emission points in the 
current NESHAP rather than the 99 percent UPL emission standard 
developed using only data from Asarco. The commenter explained that 
this limit should be applied at their aisle scrubber stack, which is 
the emission point for emissions from their Hoboken converter process 
fugitive capture system and their anode refining department, thus each 
affected source would be subject to the same 23 mg/dscm limit. The 
commenter added that the EPA does not have sufficient data to set a 
mass rate for the anode refining department MACT floor since the only 
data used to set the limit are from Asarco, which does not reflect the 
operating performance of their anode refining department and does not 
reflect the best 5 sources as is required by the EPA's procedure for 
source categories with less than 30 sources. The commenter explained 
that they cannot provide performance tests of their anode refining 
department emissions using EPA methods because of the duct 
configuration of the baghouse controlling these emissions. However, in 
their comment letter they submitted an engineering evaluation which 
characterized the flowrate and particulate emissions for the anode 
refining department's baghouse. The engineering evaluation was not 
conducted following EPA methods. The commenter used the data from the 
engineering evaluation with the data the EPA used in the development of 
the 99 percent UPL (i.e., Asarco's data) to estimate a revised MACT 
standard, 7.3 mg/dscm. The commenter stated that the purpose of the 
recalculation of the MACT standard was to demonstrate their argument 
that more data collection is necessary to support the development of a 
representative MACT standard for the anode refining department.
    Response: First, as described in the preamble of the 2022 proposal, 
the emission standard for the anode refining point source was proposed 
pursuant to CAA section 112(d)(2) and (3). This standard is not being 
proposed pursuant to CAA section 112(d)(6). The 1998 proposal for 
primary copper smelting identified the anode refining department in the 
definition of primary copper smelters; however, the EPA did not have 
sufficient data at the time to set a standard for this emission source. 
In contrast, in the 2007 area source NESHAP for primary copper 
smelting, data were available to set an emissions standard for the 
anode refining department. With the recently acquired Asarco data, we 
now have sufficient data to develop a MACT floor emission standard for 
the anode refining point source at major sources. The Asarco data 
includes 9 data points, which exceeds the minimum sample size of 3 data 
points necessary to develop a MACT floor. Therefore, we disagree that 
we have insufficient data to develop the emission standard. We also do 
not find the data included in Freeport's engineering evaluation 
appropriate to include in the MACT floor dataset since these data were 
not collected following EPA methods. In regard to the comment that the 
MACT floor limit does not reflect the best 5 sources, there are only 
two major sources in this category, and as stated, only one of these 
major sources had valid data from an anode refining department. We used 
all available valid data from the best performing sources for which the 
EPA could reasonably obtain emissions information in the category, 
which is in accordance with CAA section 112 (d)(3)(B).
    Comment: One commenter explained that the configuration of their 
anode refining department baghouse makes the proposed test methods 
infeasible. The commenter stated that the anode refining department 
exhaust at their facility is controlled by a baghouse, which is ducted 
to the aisle scrubber where it combines with exhaust from the 
facility's Hoboken converter process fugitive capture system. The point 
of emission for their anode refining department exhaust is the outlet 
of the aisle scrubber. The commenter stated implementing the 
alternative emission limit option to comply with the anode refining 
limit (as proposed by the EPA) is not feasible due to the inability to 
measure flowrate using EPA Method 1 in the duct between the baghouse 
outlet and aisle scrubber inlet. The commenter explained the ductwork 
does not have enough straight passes to measure flowrate according to 
EPA Method 1.
    Response: Based on reviewing information submitted by the commenter 
and observations made by the EPA during a November 7, 2023, site visit 
to the facility, the EPA agrees that there is currently no viable 
testing location for flowrates using EPA Method 1 from the anode 
refining department baghouse to the aisle scrubber. In light of this 
new information, we agree that the use of the alternative emission 
limit is not an option for demonstrating compliance with the anode 
refining department for this facility. However, this alternative 
emission limit procedure may be appropriate at a new facility; thus, we 
are finalizing the proposed amendment to add the anode refining 
department to the list of emission sources which could be included in 
the emission alternative limit calculation option. However, as 
discussed elsewhere, we are promulgating a limit for the combined 
stream of the anode refining department and Hoboken converter process 
fugitive capture system (i.e., the Freeport aisle scrubber). Based on 
the data provided by the Freeport facility in their section 114 
information request response, an estimated 75 percent of the 
particulate emissions emitted from the aisle scrubber are from the 
Hoboken converter process fugitive capture system while the remaining 
25 percent are from the anode refining baghouse. The emission standard 
for the combined stream of the anode refining department and Hoboken 
converter process fugitive capture system based on 61 percent control 
of the emissions by a baghouse controlling the emissions from the

[[Page 41672]]

Hoboken converter process fugitive capture system is 4.1 mg/dscm. The 
emission standard for the combined stream of the anode refining 
department and Hoboken converter process fugitive capture system is 
more stringent than the anode refining department emission standard 
alone (5.8 mg/dscm). Therefore, we are finalizing that compliance with 
the emission standard for the combined stream of the anode refining 
department and Hoboken converter process fugitive capture system 
demonstrates compliance with the anode refining department emission 
standard.
    Comment: One commenter stated that in the 2022 proposal the EPA 
proposed a new MACT floor limit for the anode refining department. The 
commenter requested clarification if the PM limits for the aisle 
scrubber in the 2023 supplemental proposal replace the anode refining 
department limit in the 2022 proposal (because their anode refining 
department baghouse vents to the aisle scrubber), or if the EPA intends 
to retain the separate anode baghouse requirement.
    Response: As described in section IV.B. of this preamble, we are 
promulgating a particulate emission limit for the combined stream of 
the anode refining department and the Hoboken converter process 
fugitive capture system (i.e., aisle scrubber) as proposed in the 2023 
supplemental proposal, as well as an independent anode refining 
department emission limit as proposed in the 2022 proposal. Compliance 
with the anode refining department emission limit will be demonstrated 
by complying with the appropriate limit, i.e., if there is a combined 
emission stream then the affected source will comply with the combined 
emission standard, or if the anode refining department is independent 
(i.e., not combined with other emission streams), then the affected 
source will comply with the independent limit for anode refining 
department.
d. What is the rationale for our final approach and final decisions for 
the anode refining point source revisions made pursuant to CAA section 
112(d)(2) and (3)?
    As discussed in the 2022 proposal preamble, the 1998 proposal for 
primary copper smelting major sources identified anode refining in the 
definition of primary copper smelters. However, at that time, the EPA 
did not have sufficient data to set an emission limit for anode 
refining, and therefore did not propose specific emission standards for 
anode refining operations in the major source NESHAP. The 2007 area 
source NESHAP includes emission standards for anode refining operations 
at area sources. Therefore, in the 2022 proposal, we concluded that 
anode refining is part of the source category and emits HAP emissions. 
In the 2022 proposal, we considered a BTF option, but did not consider 
going BTF in this case due to cost effectiveness. Pursuant to section 
112(d)(2) and (3), we are finalizing, as proposed in the 2022 proposal, 
a MACT floor PM limit of 5.8 mg/dscm as a surrogate for metal HAP for 
new and existing anode refining departments. We are finalizing, as 
proposed, that compliance with the PM emissions limit for the anode 
refining department will be demonstrated through an initial performance 
test followed by a compliance test at least once per year. We are also 
finalizing to include the anode refining department as an emission 
source to be included in the alternative emission limit calculation for 
new facilities.
    Based on the comments received on the 2022 proposal and the 2023 
supplemental proposal and on information collected during a November 7, 
2023, site visit to the Freeport facility, we are promulgating that 
compliance with the combined emission standard of 4.1 mg/dscm, for the 
combination of anode refining department emissions and Hoboken 
converter process fugitive capture system emissions (being promulgated 
under CAA section 112(d)(6) as described in section IV.B. of this 
preamble) will demonstrate compliance with the anode refining MACT 
floor PM limit. Under section 112(d)(6), we are finalizing initial and 
continuous compliance requirements for the combined emission standard 
including initial and subsequent annual performance testing. The 
combined standard and associated compliance requirements will ensure 
that affected sources can demonstrate compliance with the rule 
requirements.
2. Process Fugitive Emissions From Roofline Vents
a. What did we propose for process fugitive emissions from roofline 
vents pursuant to CAA section 112(d)(2) and (d)(3)?
    As noted previously in the preamble for this final rule, the 
standards and associated compliance requirements for the process 
fugitive emissions from roofline vents source are being finalized 
pursuant CAA section 112(f)(2) to address unacceptable risk for the 
source category as well as pursuant to CAA section 112(d)(2) and (3). 
As proposed in the 2022 proposal and the 2023 supplemental proposal, we 
are promulgating the same emission standard to reduce risk to a level 
that would be considered acceptable and to satisfy the requirements of 
CAA section 112(d)(2) and (3). As discussed in the context of risk in 
section IV.A. of the preamble for this final rule, we proposed emission 
standards for the process fugitive emissions from roofline vents. In 
the 2022 proposal, we proposed separate standards for each roofline 
vent (i.e., smelting vessels, copper converter department, and anode 
refining department) based on emissions data received from the Freeport 
facility. We performed a BTF analysis for additional controls of each 
roofline vent and concluded in the 2022 proposal that a BTF standard 
was appropriate for the anode refining process fugitive roofline vent 
while MACT floor standards were appropriate for the smelting and copper 
converter roofline vents.
    During the comment period for the 2022 proposal, we received 
additional test data of the roofline vents from the Freeport facility. 
We received comments from both facilities in the major source category 
requesting that the roofline vent be a combined limit because there is 
comingling of emissions in the building where the processes are 
located. We received significant comment regarding the proposed test 
methods for demonstrating compliance with the roofline vent emission 
standards. We also received comments on our cost estimates for the BTF 
control option of the anode refining roofline vent.
    In the 2023 supplemental proposal, we proposed a combined limit. 
The combined limit was calculated using the 99 percent UPL methodology. 
Specifically, for calculating the combined emission limit, we first 
determined the 99 percent UPL of the combined emission rates based on 
all test data now available for filterable PM. We then determined the 
average fraction of emissions which are attributable to the anode 
refining roof vent (72 percent). Then we adjusted the anode refining 
roof vent's portion of the 99 percent UPL by reducing that portion of 
the value by 90 percent. We also adjusted our costs in response to 
public comments on the proposed option to reflect the design 
requirements at the Freeport facility primarily by increasing the 
baghouse flowrate, lowering the air to cloth ratio and adding a lime 
injection system. The revised capital costs were $10.2 million and 
annualized costs were $2.14 million. The baghouse is expected to 
achieve 4.59 tpy reduction of lead and arsenic with a cost

[[Page 41673]]

effectiveness of $467,000/ton metal HAP.
    In addition, in the 2022 proposal we solicited comment on a lead 
limit for the roofline vents in addition to, or instead of, the PM 
limit for the anode refining roof vents. The agency considered a 
possible lead limit of 0.26 lb/hr as a potential BTF MACT limit for 
anode refining process fugitive emissions.
b. How did the requirements for process fugitive emissions from 
roofline vents proposed pursuant to CAA section 112(d)(2) and (3) 
change since proposal?
    As discussed in this preamble, we are promulgating the combined BTF 
PM limit of 6.3 lb/hour for the roofline vents as proposed in the 2023 
supplemental proposal. The BTF control cost estimates were updated to 
incorporate the most current bank prime interest rate resulting in a 
small increase in total annualized costs which are now estimated as 
$2.30 million with a resulting cost effectiveness of $500,000/ton metal 
HAP with 4.6 tpy (rounded from 4.59 tpy) reduction of lead and arsenic. 
The revised cost estimates are documented in the memorandum Cost 
Estimates for Enhanced Capture and Control of Process Fugitive 
Emissions from the Anode Refining Operations at Freeport--REVISED, 
which is available in the docket for this rulemaking. The cost 
estimates were otherwise unchanged and the adjustments do not change 
our conclusions about the necessity of promulgating the BTF standard. 
However, we received significant comment on the proposed compliance 
test methods. To address some of the concerns raised by the commenters, 
we are promulgating revised methods and allowing the use of Federal 
reference method (FRM) and Federal equivalent method (FEM) monitors as 
discussed in section IV.C.2.c.
    We are promulgating a lead emission limit of 0.326 lb/hour for 
minimizing process fugitive emissions from any combination of roofline 
vents associated with the Peirce-Smith copper converter department, 
Inco flash furnace and the anode refining department, at existing 
sources. This emissions limit reflects the estimated reductions that 
will be achieved by the design standards described in section IV.B. We 
are also finalizing that facilities must demonstrate compliance with 
this emission limit once per year. We note that Peirce-Smith converters 
are batch converters and the NESHAP prohibits the use of batch 
converters for new sources. Therefore, this lead limit is not relevant 
for new sources.
c. What key comments did we receive on the proposed requirements for 
process fugitive emissions from roofline vents pursuant to CAA section 
112(d)(2) and (3) and what are our responses?
    Comment: Numerous comments were received on the proposed test 
methods for measuring PM at roof vents, which include EPA Test Methods 
1, 2/2F/2G, 3/3A/3B, 4, 5D and Oregon Method 8. Most comments were that 
the proposed test methods are not suited for testing PM from roof 
vents; that MiniVol portable samplers should be used for sampling PM at 
the roof vents instead of the proposed test methods; and that the 
proposed test methods are unsafe to conduct at rooflines.
    Commenters discussed the lack of isokinetic conditions at the 
roofline, which they stated inhibits the use of Method 1. For example, 
a commenter explained that Method 1 provides two alternative 
procedures: a ``simplified procedure,'' and an ``alternative 
procedure.'' Citing section 1.2 of the method, the commenter stated the 
simplified procedure ``cannot be used when the measurement site is less 
than 2 stack or duct diameters or less than a half diameter upstream 
from a flow disturbance.'' The commenter stated that neither stack 
diameters nor duct diameters can be defined for the smelter facilities' 
roofline vents, within the meaning and purposes of section 1.2. With 
regards to the alternative procedure, the commenter stated this 
procedure depends on the ability to develop representative pitch and 
yaw angles of the gas flow to be sampled, based on directional flow-
sensing probe measurements of pitch and yaw angles at forty or more 
traverse points within the flow. The commenter stated this procedure is 
not possible to perform at the smelter facilities' roofline vents 
because fugitive emissions at the vents occur at a variety of angles 
that are constantly changing due to ambient winds.
    Another commenter discussed the lack of isokinetic conditions at 
the roofline and referenced a feasibility study (EPA-HQ-OAR-2020-0430-
0062) that concluded that the roofline vents at the Miami smelter 
cannot meet the minimum methods of Method 1, including either the 
simplified procedure or alternative procedure. The commenter stated 
that if Method 1 cannot be utilized effectively at the 2 facilities 
subject to the major source rule, the rule is not practical to 
implement or enforce.
    A commenter discussed in depth the limitations of Method 5D, 
stating that, unlike a positive pressure baghouse for which Method 5D 
was designed, the roofline vent air flow is induced by natural buoyance 
of the warmer gas inside the smelter building and by outside air wind 
pressures--not by use of a forced air blower like those used in a 
baghouse. The commenter referenced an illustration in a technical 
analysis of the proposed vent test methods, which shows that the flow 
rate varies significantly over short periods of time and occasionally 
is negative (i.e., air flows into the vent). Another commenter stated, 
``FMMI identified the incompatibility of Method 5D to the roofline vent 
configurations as part of its original comments on April 26, 2022 . . . 
Nevertheless, the EPA left the issue unaddressed in the supplemental 
rule proposal, and the agency has not provided any guidance or 
technical analysis explaining how Method 5D could be adapted to the 
distinctly different conditions presented by the roofline vents.'' A 
commenter stated because EPA Method 5D is not compatible with the low, 
variable air velocities and physical configuration of the roofline 
vents, FMMI has utilized a sampling methodology and test protocol 
negotiated with the ADEQ (the ``ADEQ test method'').
    Commenters advocated using MiniVol portable air samplers as an 
alternative to the proposed test methods for measuring PM from roof 
vents. They stated that using MiniVol portable air samplers is the most 
representative sampling method for the roofline emissions application, 
and while not a FRM sampler, they provide results that closely 
approximate data from FRM samplers to obtain representative 
concentrations of PM without the need for isokinetic sampling. The 
commenter noted that the portable air samplers can be run concurrently 
at several locations along the roofline, which the commenter notes 
offers several benefits: (1) fluctuations in flows and emissions along 
the roofline are better managed, (2) sampling is not dependent on 
linear air flow, so constant adjustments are not required, and (3) 
sampling can occur for longer periods of time, which provides a more 
representative sample of the process operations occurring in the 
smelter buildings. The commenter noted use of this sampling protocol 
will require the collection of velocity and temperature measurements 
using the existing roofline monitoring system equipment. As an added 
benefit, the portable air samplers also are capable of speciating 
samples of PM, PM10, and PM2.5.
    A commenter noted that Asarco's 2015 consent decree with ADEQ, 
which governs the operation of their Hayden

[[Page 41674]]

smelter, requires process fugitive emissions studies (FES) pursuant to 
a protocol (``FES Protocol'' or ``Protocol'') approved by the EPA on 
May 24, 2017. Within the FES Protocol is a determination that process 
fugitive PM emissions at the roofline shall be quantified via a 
sampling methodology that centers on the use of MiniVol portable air 
samplers at the roofline vents. The commenter stated that the EPA's 
approval of the Protocol constitutes a determination by the EPA that 
this sampling method is appropriate for determining the rate of 
fugitive PM emissions at the roofline. The MiniVol sampler, in 
particular, is a low-flow sampler, which is well-suited to low, 
variable air flows at the roofline--unlike the iso-kinetic sampling 
methods specified in paragraph (e)(1) of proposed 40 CFR 63.1450. The 
commenter attached copies of the Protocol and the EPA's approval of the 
Protocol to their comment letters submitted on the 2022 proposed RTR 
and on the 2023 supplemental proposal (Docket ID Nos. EPA-HQ-OAR-2020-
0430-0135 and EPA-HQ-OAR-2020-0430-0204, respectively).
    A commenter stated the final rulemaking should include a provision 
that explicitly authorizes the use of MiniVol portable air samplers, 
together with appropriate temperature and flow sensors to determine PM 
emissions at the roofline. The commenter advocated the use of a 
fugitive emissions monitoring protocol specific to the relevant smelter 
and approved by the EPA's Office of Air Quality Planning and Standards, 
Measurement Technology Group (MTG) or other reviewing body such as ADEQ 
and believes (a) 6 months after the date of the final rulemaking's 
publication in the Federal Register would be an appropriate deadline 
for submittal of the protocol for agency approval; and (b) 2 years 
after agency approval of the protocol would be an appropriate deadline 
for commencing measurements of the rate of fugitive PM emissions at the 
roofline to determine whether they exceed the fugitive PM emissions-
rate limit. Correspondingly, the commenter noted the final rulemaking 
should provide that, during the pendency of the protocol's 
implementation, only the work practice standards and operation and 
maintenance requirements of the revised subpart QQQ rules shall apply 
to the process fugitive PM emissions. This would be consistent with 42 
U.S.C. 7412(h)(1)-(2)(B) and the approach the EPA took in the Mercury 
and Air Toxics Standards (MATS) and Industrial Boilers rulemakings.
    The commenter stated that the ADEQ test method was utilized to 
collect all of the emission data that the EPA relied on for the UPL 
calculation that is the sole basis for the combined roofline PM 
emission limit in the supplemental proposed rule. According to the 
commenter, it is not appropriate for the EPA to set emission limits 
based upon the ADEQ test method and then prohibit the use of that very 
same method to demonstrate compliance. If the ADEQ test method was good 
enough to set enforceable emission limits, it should also be good 
enough to demonstrate compliance. The commenter stated that if the ADEQ 
test method (or some reasonable modification of that method) does not 
meet the EPA's requirements, then no limit should be established at 
this time because that approach necessarily means that a valid data 
basis for a limit does not yet exist. If that is indeed the EPA's 
position FMMI and the EPA can work together to develop an acceptable 
test method, FMMI can collect the necessary data to support the 
calculation of a UPL based on that agreed method, and the agency can 
set emission limits based on that data set.
    In a related point, a commenter stated that they are concerned that 
the proposed roofline lead limit is based on data collected using 
samplers that are not designated as an FRM. Use of non-FRM sampler data 
could create a standard that is not achievable if tested using an FRM. 
It is unclear from the EPA's proposed rule how to address a potential 
discrepancy between a standard based on non-FRM and testing using an 
FRM. The commenter goes on to say that the EPA's proposed PM limit was 
established using data that were collected using a method other than 
EPA Method 5. Another commenter has similar concerns with the EPA's 
rule in regard to the proposed limit being based on data collected 
using samplers that are not designated as an FRM: First, they state it 
is not clear from the EPA's rule that a Method 5 test conducted at the 
same time would have produced the same result as the alternative method 
used to obtain the data the rule is based on. Second, they state it is 
unknown whether this standard is achievable, as determined by the 
proposed test methodology.
    Lastly, commenters had concerns about the safety of the personnel 
conducting testing at the roofline. The commenter stated it would be 
unsafe, due to the elevated temperature environment and other 
conditions at the roofline, for humans to perform roofline activities 
required by paragraph (e) of proposed 40 CFR 63.1450. Many areas of the 
roofline are currently only accessible by narrow catwalks that do not 
currently have approved tie-off points or sufficient space to 
accommodate the personnel and the required sampling equipment. Some 
roofline areas require respirators or other personal protective 
equipment, and the EPA's proposed testing methods would require 
continuous presence of multiple personnel working directly in the 
pathway of exiting fumes for 3, 12-hour test runs. The commenter stated 
the Method 5 sampling protocol requires adequate sample locations to 
account for variations in the flows along the roofline, which then 
necessitates a large number of sampling staff to be located in a 
dangerous, high temperature environment for extended periods of 12 
hours or more. The commenter noted the temperatures at the roofline can 
reach 140 degrees Fahrenheit and pose a significant safety concern for 
the testing personnel.
    Response: In reviewing the comments and as a result of a site 
visit, the EPA is revising the methods for the roof-vent testing. For 
sample location determination, if EPA method 1 is inappropriate, the 
facilities need to use method 5D, section 8.1.3, Roof Monitor or 
Monovent, and also use section 8.2 to determine how many traverse 
points should be sampled or have proposed sampling locations approved 
by EPA Office of Air and Radiation (OAR), Office of Air Quality 
Planning and Standards, MTG or the delegated authority. Due to the 
variability in the flow rates, an anemometer may be used to determine 
the flow. For the PM concentration measurements, a constant sample flow 
rate and mass volume is required due to the highly variable process 
flow rate. EPA method 17 may be used for this constant flow rate 
sampling. EPA Method 17 particulate matter samples will be collected at 
the roofline vent temperatures to maintain the same temperature basis 
as the samples used in setting the standard. EPA Methods 5 and 5D have 
been removed since these methods require heating the filter to 248 
 25 Fahrenheit, which would not be representative of the 
roofline temperatures. It is understood that isokinetics may not be met 
with this sampling and this calculation is waived for this sampling.
    The MiniVol samplers are not EPA- approved samplers. There is a 
concern because these are battery operated and may not provide a 
constant rate of sampling. As an alternative, an approved FRM or FEM 
ambient PM monitor may be used, which will also address the commenter's 
safety

[[Page 41675]]

concerns. A list of designated reference and equivalent methods is 
provided here: https://www.epa.gov/amtic/air-monitoring-methods-criteria-pollutants. However, tapered oscillating microbalances are not 
appropriate for this sampling. The FRM or FEM ambient PM monitor must 
be able to tolerate temperatures up to 150 degrees Fahrenheit.
    The commenter has raised concerns on the use of the MiniVol sampler 
to set the standard while different methods are used for determining 
compliance. The EPA has mitigated these issues through the adaptations 
to the methodology finalized, the use of calibrated anemometer for low 
and variable process flow rates, fixed rate sampling and the allowance 
for in stack filter methodology (EPA Method 17). The primary sampling 
difference between the methods now is the more stable operation of the 
EPA Method 17 sampling system or an FRM/FEM, ensuring that the sampled 
flow rate is consistent.
    The EPA alternative methods approval is conducted by the 
Measurement Technology Group (MTG). The MiniVol roof-vent sampling 
protocols/sampling methods have not been submitted or approved by MTG. 
The Asarco protocol included FRM sampling side-by-side with the MiniVol 
sampling. This side-by-side sampling could use Method 301 to validate 
the MiniVol samplers, but the proposed sampling has not yet occurred. 
This Method 301 validation could still occur, and the data could be 
used to support an alternative method approval from MTG. If these 
revised methods are not appropriate or the tester/facility wants to use 
alternative methods, the tester/facility can apply for an alternative 
test method approval through MTG. A Method 301 study should be 
conducted to verify that the selected monitors used provide equivalent 
data to the EPA methods.
    Comment: A commenter agreed with the EPA's reasoning and 
determination not to propose a BTF lead emissions limit in addition to, 
or instead of, the fugitive PM emissions limit in proposed 40 CFR 
63.1444(i)(3). Similarly, another commenter stated that, in response to 
EPA's request for comments, an additional lead limit on the roofline 
vents is not necessary. They explained that they agreed with the EPA's 
conclusion that PM is the most appropriate surrogate for metal HAPs.
    Response: While we agree that PM is an appropriate surrogate for 
metal HAP, we are also finalizing a process fugitive lead limit for 
facilities using flash furnaces and associated with the Peirce-Smith 
converters of 0.326 lb/hr for a combination of roof vents associated 
with Peirce-Smith copper converter department, Inco flash furnace and 
the anode refining department. We estimate that this final standard 
will reduce lead emissions by 0.39 tpy.
    Comment: Commenters requested that the EPA establish direct lead 
limits, either in addition to or instead of the PM limit because it is 
one of the risk drivers for this source category and would be 
appropriate to control for it directly.
    Response: We have determined that filterable particulate is an 
adequate surrogate for lead and other HAP metals for this source 
category. The use of PM as a surrogate for particulate metal HAP is 
consistent with the approach used to limit particulate metal HAP 
emissions from other copper smelting processes in the current NESHAP 
and for many other source categories (i.e., Ferroalloys Production, 
Integrated Iron and Steel Manufacturing, and Integrated Iron and Steel 
Foundries). Therefore, providing PM emission standards which require 
reductions as a surrogate for metal HAPs is expected to result in 
commensurate reductions of metal HAP. We are also finalizing a process 
fugitive lead limit for facilities using Inco flash furnaces and 
Peirce-Smith converters of 0.326 lb/hr for a combination of roof vents 
associated with the Peirce-Smith copper converter department, Inco 
flash furnace and the anode refining department which we estimate will 
reduce lead emissions by 0.39 tpy.
d. What is the rationale for our final approach and final decisions for 
the process fugitive emissions from roofline vents revisions made 
pursuant to CAA section 112(d)(2) and (3)?
    As described in the 2022 proposal and in the 2023 supplemental 
proposal, the 2002 major source NESHAP does not include standards for 
process fugitive emissions from the rooflines of smelting vessels, 
converters, or anode refining operations, except for an opacity limit 
for converter roof vents that applies during testing. Therefore, we are 
finalizing, as proposed in the 2023 supplemental proposal, a BTF 
combined PM limit of 6.3 lb/hr as a surrogate for metal HAP for new and 
existing process fugitive emissions from roofline vents pursuant to CAA 
section 112(d)(2) and (3). As described in section IV.A., we are also 
finalizing this combined roofline PM limit under CAA section 112(f) to 
reduce emissions of HAP metals (especially lead and arsenic, which are 
two persistent, bioaccumulative and highly toxic HAPs), and their 
associated risks, to achieve acceptable risks levels. We are 
finalizing, as proposed, that compliance with the PM emissions limit 
for the process fugitive emissions from roofline vents will be 
demonstrated through an initial performance test followed by a 
compliance test at least once per year. Based on comments we received 
on the 2022 proposal and the 2023 supplemental proposal, we are 
finalizing adaptations to the test methods by which compliance with 
this limit can be demonstrated including the use of fixed rate sampling 
and the allowance for in stack filter methodology (EPA Method 17). The 
costs for Freeport to comply with this combined PM limit are described 
in section IV.C.2.b., and we estimate that Asarco can already comply 
with this limit and therefore will not incur costs to comply with the 
combine PM roofline limit except testing costs. We estimate that both 
facilities will incur testing costs of $107,000 per year to comply with 
the performance test requirements.
    In addition, we are finalizing a lead emission limit of 0.326 lb/
hour to minimize process fugitive lead emissions from any combination 
of roofline vents associated with Peirce-Smith copper converter 
departments, Inco flash furnaces and the anode refining departments, at 
existing sources. This limit will only apply to the Asarco facility 
(since they are the only existing major source with Peirce-Smith copper 
converter departments and Inco flash furnaces), and we estimate this 
will reduce metal HAP by 0.39 tpy and ensure that future violations of 
the lead NAAQS will not occur. As mentioned in section IV.B.2. of this 
preamble, Asarco has been a major contributer to the Hayden Arizona 
lead NAAQS non-attainment status. This limit is consistent with the 
modeling demonstration submitted by the facility to the state in 
support of a revision to the lead SIP. This document is available in 
the docket for this action (Docket ID No. EPA-HQ-OAQ-2020-0430). As 
discussed in section IV.B., we are also promulgating design standards 
under CAA section 112 (d)(6) that will ensure this limit is met. As 
discussed in section IV.B., the costs to comply with the design 
standards are already expected to be incurred by the facility. We are 
finalizing, that compliance with the lead emissions limit for the 
process fugitive emissions from roofline vents will be demonstrated 
through an initial performance test followed by a compliance test at 
least once per year. The facility can test for lead at the same time as 
the performance test for PM; however, they will have some

[[Page 41676]]

additional costs for the laboratory analysis that we estimate to be 
$18,000 per year.
3. Mercury
a. What did we propose for mercury emissions pursuant to CAA section 
112(d)(2) and (3)?
    In the 2022 proposal, the EPA proposed a BTF mercury limit of 
0.0043 lb/hr for existing sources, based on emissions data from 
Freeport and Asarco, and a MACT floor mercury limit of 0.00097 lb/hr 
for new sources, based on emissions data from Asarco. As noted in the 
preamble of the 2022 proposal, in order to comply with the proposed 
emission limit for existing sources, the EPA expected that the Freeport 
facility would have to install and operate an activated carbon 
injection (ACI) system and a polishing baghouse on the stack emissions 
release point, the acid plant. The EPA expected the installation of 
these additional controls would result in a 90 percent reduction of 
mercury emissions from the acid plant source and that the cost-
effectiveness of mercury control would be $27,500 per pound (in 2019 
dollars).
    During and after public comment period of the 2022 proposal, the 
EPA received a number of comments and additional data concerning the 
BTF limit for existing sources including:
     Mercury testing results obtained in 2018-2021 by the 
Freeport facility which did not fully follow EPA Method 29;
     Additional mercury testing results collected at the 
Freeport facility in 2022 which fully followed EPA Method 29; and
     Comments regarding the technical infeasibility of adding 
mercury controls (e.g., polishing baghouse with ACI) at the acid plant, 
including explanations that the conditions of the acid plant exhaust 
streams are unsuited for the control option since the stream has a high 
moisture content, low mercury concentrations, and high concentrations 
of SO2/SO3 which inhibit mercury removal.
    As discussed in the 2023 supplemental proposal, the EPA evaluated 
the emissions data from all of Freeport's performance tests (i.e., 
2018-2022) and concluded that only the test conducted in 2022 which 
fully followed Method 29 should be used in the MACT floor emission 
limit development. The EPA also agreed that characteristics of the 
exhaust stream from the acid plant stack and equipment configuration at 
the acid plant may inhibit mercury control (e.g., moisture content, 
acid gas content, mercury concentration) which could result in 
diminished emission reductions. Therefore, we evaluated controlling 
mercury from the aisle scrubber stack and the vent fume stack and 
determined the latter was best suited for mercury control (see 
discussion in the 2023 supplemental proposal). Based on a new stack 
location and a new emissions data set, which includes the original 
Asarco data and data from Freeport's 2022 test, the revised mercury 
limit for existing sources in the 2023 supplemental proposal, as 
determined using the 99 percent UPL approach, is a MACT floor limit of 
0.033 lb/hr for combined facility wide emissions. We also evaluated BTF 
control options in the 2023 supplemental proposal and concluded that 
the costs were unreasonable, and we proposed the MACT floor emission 
standard. We proposed that compliance with the mercury emissions limit 
for new and existing sources would be demonstrated through an initial 
compliance test for each of the affected sources (e.g., furnaces, 
converters, anode refining) followed by a compliance test at least once 
every year.
b. How did the mercury emissions standard made pursuant to CAA section 
112(d)(2) and (3) change since proposal?
    The mercury emission standard for new sources, 0.00097 lb/hr, is 
being promulgated as proposed in 2022. In the 2023 supplemental 
proposal, we proposed a revised mercury emission standard of 0.033 lb/
hr for existing sources and are finalizing that standard as proposed. 
Both emission standards are based on the MACT floor.
c. What key comments did we receive on the mercury revisions made 
pursuant to CAA section 112(d)(2) and (3) and what are our responses?
    Comment: Commenters contend that the EPA does not have sufficient 
data to develop a MACT floor for mercury. They stated that they do not 
believe the single 3-run test results are sufficient to establish the 
proposed MACT floor emission standard for existing sources. The 
commenter noted there was significant run-to-run variability which the 
commenter stated can be attributed to the profile of the process feed 
and the nature of a batch process. Commenters noted that additional 
performance testing of mercury will be conducted at the Freeport 
facility in the fourth quarter of 2023, and first quarter of 2024 using 
EPA Method 29, and they asked that the EPA allow for submittal and 
consideration of these data (which they say they will be able to 
provide at least several weeks prior to the May 2, 2024, deadline for 
final rule publication) when establishing limits in the final rule. In 
the absence of additional data, commenters believe that a 
representative MACT floor cannot be established, and any regulatory 
action should be postponed or limited to workplace standards. They 
rationalized this comment by citing the NESHAP for Secondary Lead 
Smelting (77 FR 570) where the EPA did not promulgate standards because 
of incomplete testing and lack of testing data for furnaces that burn 
varying types of fuel.
    Response: As described in the 2023 supplemental proposal, the EPA 
revised its calculations by only using the stack test data that 
followed EPA Method 29. The proposed mercury standard was developed 
based on the 99 percent UPL of the available emissions data for this 
source category, which included data collected from Freeport through 
the 2022 section 114 information request from Freeport as well as test 
data from Asarco, yielding a sample size of 5 data points. The test 
report associated with Freeport's section 114 information request 
response was conducted using EPA test Method 29 and was reviewed by EPA 
measurement experts upon submission. A dataset of more than 3 data 
points meets the sample size necessary to use the 99 percent UPL 
approach to develop a MACT standard. We acknowledge that a sample size 
of 5 is considered a limited dataset; however, we have followed our 
documented approach for MACT floor development for limited datasets 
included in Appendix B of the aforementioned memorandum (Docket ID No. 
EPA-HQ-OAR-2020-0430-0153). Therefore, we disagree that we have 
insufficient data to develop a numerical emission standard based on the 
MACT floor.
    We note that we received two additional test reports from Freeport; 
one on January 29, 2024 (non-metal HAPs) and one on February 16, 2024 
(mercury), well after close of the public comment period (i.e., 
September 22, 2023) and have been notified that Freeport plans to send 
a third test report in mid-April 2024. Based on a preliminary review of 
the new test data, we determined that some tests were not valid due to 
deviation from the EPA method and that incorporation of the valid tests 
would not result in significant changes to the proposed emission 
limits. We did not incorporate these late-submitted data for two timing 
related reasons. First, other stakeholders would not have an 
opportunity to review and comment on these new data; and second, given 
the court-ordered promulgation deadline of May 2, 2024, we had 
insufficient time to complete the

[[Page 41677]]

necessary quality control and assurance of the data, and to perform new 
calculations and analyses to establish revised limits before the May 2, 
2024, deadline. Thus, we are promulgating the existing source MACT 
floor emission standards for mercury, as well as for the other non-
metal HAP, as proposed in the 2023 supplemental proposal and as 
discussed in sections IV.C.3. and IV.C.4. of this preamble.
    Comment: Some commenters expressed support for the decision in the 
2023 supplemental proposal not to move forward with a BTF standard for 
mercury, while other commenters suggested that the EPA adopt the BTF 
standard for mercury. Commenters stated that indirect costs including 
engineering, procurement, and construction management, as well as 
startup costs had not been included in our estimates. Specifically 
concerning costs for baghouses, commenters stated that most modern 
baghouses are of the pulse jet, rather than shaker style, 
configuration.
    Response: As described in the 2023 supplemental proposal, the EPA 
re-proposed a MACT floor standard for mercury after considering the 
technical feasibility and costs of BTF control options. In 
consideration of the comments regarding costs, we performed a holistic 
review of the cost estimates for controls included in this rulemaking. 
As described in the 2023 supplemental proposal, we estimated costs for 
controlling mercury at the vent fume stack using a polishing baghouse 
with ACI. We found that our BTF cost estimates for mercury controls 
omitted indirect costs and assumed costs for a shaker style baghouse. 
In response to the comments received on the 2023 supplemental proposal, 
we have revised our BTF cost estimates for mercury control of the vent 
fume stack at the Freeport facility to include indirect costs and to 
more appropriately assume a pulse jet configuration baghouse. The 
details of these revisions can be found in the memorandum Estimated 
Cost for Beyond-the-floor Controls for Mercury Emissions from Primary 
Copper Smelting Facilities--REVISED, available in the docket for this 
rulemaking. Our revised estimates of the cost of BTF mercury are 
capital costs of $10.7 million and total annualized costs of $3.0 
million. We did not receive additional test data or other information 
that would result in revisions to the expected emission reductions we 
presented in the 2023 supplemental proposal. Using the expected 
reductions, 40.5 lb/yr, the resulting cost effectiveness is $73,300/lb 
mercury. We continue to maintain, as proposed in the 2023 supplemental 
proposal, that the cost effectiveness for the BTF control of mercury is 
unreasonable and are promulgating the MACT floor emission standard for 
existing sources.
d. What is the rationale for our final approach and final decisions for 
the mercury revisions made pursuant to CAA section 112(d)(2) and (3)?
    As described in the 2022 proposal and the 2023 supplemental 
proposal, the 2002 major source NESHAP does not include standards for 
mercury. We are finalizing, as proposed in the 2022 proposal, the new 
source MACT floor mercury limit of 0.00097 lb/hr mercury. As stated in 
the 2022 proposal, the new source MACT floor mercury limit was 
calculated based on emissions data from the best performing facility, 
which is Asarco in this case. We are finalizing, as proposed in the 
2023 supplemental proposal, the existing source MACT floor mercury 
limit of 0.033 lb/hr mercury. As discussed in section IV.C.3.c. of this 
preamble, we made some revisions to the cost of mercury controls that 
were included in the 2023 supplemental proposal. These revisions 
improved the completeness of our estimates but did not change our 
conclusion that the costs of the BTF option for controlling mercury 
with a polishing baghouse and ACI at the vent fume stack are 
unreasonable ($73,000/lb mercury reduced). We also considered other BTF 
options, but all other options were less cost-effective than additional 
controls of the vent fume stack using the baghouse/ACI option. We note 
the BTF options we considered are higher than historic acceptable cost 
effectiveness values for mercury. The highest historic acceptable cost-
effective values in the 2011 final MATS rule were up to $22,400 per 
pound of mercury reduced in 2007 dollars (which equates to about 
$32,000 per pound in current dollars). We are finalizing, as proposed, 
that compliance with the mercury emissions limit for new and existing 
sources will be demonstrated through an initial compliance test for 
each of the affected sources (e.g., furnaces, converters, anode 
refining) followed by a compliance test at least once every year.
4. Other Unregulated HAP
a. What did we propose for the unregulated HAP pursuant to CAA section 
112(d)(2) and (d)(3)?
    During the public comment period of the 2022 proposal, the EPA 
received comments claiming there were additional unregulated HAP from 
the source category beyond those we addressed in the 2022 proposal. In 
response to these public comments, the EPA issued a CAA section 114 
information request to collect further information. The information 
request was sent to the Freeport facility only, as the Asarco facility 
has been idled since October 2019. The collected data indicated the 
following additional unregulated pollutants are emitted from the source 
category: benzene, D/F, HCl, chlorine, PAH (including naphthalene), and 
toluene. These pollutants are mainly emitted due to the combustion of 
natural gas and coke. Based on this new information, the EPA proposed 
the following MACT floor emission limits for these pollutants in the 
2023 supplemental proposal:
     1.7E-03 lbs benzene/ton concentrated ore fed for new and 
existing sources;
     8.4E-04 lbs toluene/ton concentrated ore fed for new and 
existing sources;
     1.5E-03 lb/ton concentrated ore fed for HCl for new and 
existing sources;
     5.4E-03 lbs chlorine/ton concentrated ore fed for new and 
existing sources;
     1.0E-04 lbs PAH excluding naphthalene/ton concentrated ore 
fed for new and existing sources;
     2.8E-04 lbs naphthalene/ton concentrated ore fed for new 
and existing sources; and
     60 ng D/F TEQ/Mg concentrated ore fed for new and existing 
sources.
    We also proposed that compliance with the unregulated HAP emissions 
limits for each affected source will be demonstrated through an initial 
performance test followed by a compliance test at least once every 5 
years.
b. How did the unregulated HAP revisions made pursuant to CAA section 
112(d)(2) and (3) change since proposal?
    As described in section IV.C.4.a., we proposed MACT floor emission 
limits for benzene, D/F, HCl, chlorine, PAH (including naphthalene), 
and toluene. The decision not to propose BTF emission limits was based 
on the results of our BTF analysis. The BTF analysis assumed ACI or DSI 
would be installed with an existing scrubber to achieve the expected 
emission reductions. However, based on comments received on this 
analysis as discussed in section IV.C.4.c. of this preamble and the 
promulgation of additional controls for the Hoboken converter process 
fugitive capture system, we made revisions to our BTF analysis. 
Specifically, we revised the BTF control options to be the addition of 
ACI or DSI to the baghouse control device we expect will be installed 
upstream of the aisle scrubber to control

[[Page 41678]]

the Hoboken converter process fugitive capture system, rather than a 
scrubber. We revised the expected emission reductions for each 
unregulated HAP (i.e., benzene, D/F, HCl, chlorine, PAH (including 
naphthalene), and toluene) to reflect the assumption that the baghouse 
will receive about 75 percent of the loading to the aisle scrubber. The 
performance test results that were used to quantify emission reductions 
of the unregulated HAP were conducted at the outlet of the aisle 
scrubber. Therefore, we are revising the emission reduction estimates 
provided in the 2023 supplemental proposal to be based on the expected 
loading to the baghouse. We did not identify any BTF options for HCl 
because the MACT floor emission standard was set at 3 times the 
representative detection limit (3xRDL) and it is infeasible to measure 
lower levels of this pollutant. For Cl, we adjusted our expected 
emission reductions from the addition of DSI based on an expected 
control efficiency of 98 percent to 20 percent. This control efficiency 
adjustment was in response to a comment we received from Freeport. 
Freeport commented that the stack test data was taken from the aisle 
scrubber outlet; because the aisle scrubber is a caustic scrubber 
additional reduction of acid gases would be expected to be far lower 
than our proposed 98 percent. They estimated it should be 0 to 20 
percent. We agree and thus updated the expected control efficiency to 
20 percent. Finally, as noted previously in this preamble, during the 
comment period for the 2023 supplemental proposal, we received comments 
on control costs and performed a holistic review of all control cost 
estimates for this rulemaking. These comments stated that installation 
costs and indirect costs including engineering, procurement, and 
construction management, as well as startup costs and contingency had 
not been included in our estimates. We also received comments regarding 
the sizing of a DSI system for the baghouse for the Hoboken converter 
process fugitive capture system as discussed in section IV.B. The costs 
for ACI and DSI were updated to include installation and indirect costs 
including contingency for completeness and were updated in response to 
comments regarding the sizing of such systems for the baghouse expected 
to be required for controlling the Hoboken converter process fugitive 
capture system. Based on these revisions, the quantity of expected 
emission reductions from the addition of DSI or ACI was reduced, and 
the overall cost effectiveness increased for unregulated HAP. This did 
not change our proposal to base numerical emission standards for these 
pollutants on the MACT floor. The detailed emission reductions and cost 
estimates for the revised BTF options for this final rule are provided 
in a memorandum entitled Estimated Cost for Beyond-the-floor Controls 
for Unregulated HAP Emissions from Primary Copper Smelting Facilities--
REVISED, which is available in the docket for this action. Units of 
unregulated HAP were also revised from pounds (or nanograms) per ton 
(or Mg) concentrated ore fed, as applicable, to pounds (or nanograms) 
per ton (or Mg) of copper concentrate feed charged to the smelting 
vessel.
c. What key comments did we receive on the unregulated HAP revisions 
made pursuant to CAA section 112(d)(2) and (3) and what are our 
responses?
    Comment: Commenters appreciated that the EPA proposed MACT 
standards for the unregulated pollutants, but they also encouraged the 
EPA to reconsider the BTF options for control of these pollutants and 
require the additional control requirements. Commenters questioned the 
approach used to evaluate the BTF cost of controls for the nonregulated 
pollutants. By taking a pollutant-by-pollutant approach to assessing 
the cost per ton of pollution, the EPA's approach makes the cost 
assessment very high. For example, the BTF control options for benzene, 
PAH, naphthalene, and D/F were all estimated with the addition of ACI 
to the existing control device. So, the capital outlay and operational 
cost should include the tons per year (tpy) reduction of all pollutants 
instead of looking at the cost per ton for each one individually. 
Similarly, the BTF control for HCl and Cl is DSI, so one control will 
address both pollutants.
    Response: We conclude that even by evaluating the combination of 
pollutants noted by the commenter, we would still consider the costs of 
complying with the BTF standards for these HAP not reasonable in this 
case. Generally, we find that the annualized emissions of these 
unregulated HAP are quite low, and our BTF analysis which informed the 
2023 supplemental proposal concluded that the costs and cost-
effectiveness associated with the BTF options were not reasonable. For 
more details on the BTF analysis, see the memorandum entitled Estimated 
Cost for Beyond-the-floor Controls for HAP Emissions from Primary 
Copper Smelting Facilities--REVISED, which is available in the docket 
for this action.
    Comment: Commenters stated the proposed MACT standards for the 
unregulated HAP are inappropriate because they would apply to both the 
Freeport facility and the Asarco facility when they are based on 
emissions data and information collected exclusively from the Freeport 
facility, and unique to Freeport's use of fuels and other raw materials 
which are precursors to such HAP emissions from the Freeport facility. 
Commenters stated that promulgation of the MACT standards would, 
therefore, violate 42 U.S.C. 7412(d)(3)(B) for failing to be based 
empirically or predictively on HAP emissions data and information 
pertaining also to the Asarco facility. Commenters stated the EPA 
should engage with Asarco to determine whether the facility has 
relevant HAP emissions data for consideration in the rulemaking, or not 
set standards for HCl, Cl or D/F because: (1) the overall emissions 
profiles of these HAP would be particularly sensitive to variations in 
feed to the smelter, including changes in quantities and qualities of 
fuel and additives, such as coke, flux and scrap; and (2) the 
individual stack emissions profiles of these HAP--including 
distributions and emissions rates--would vary greatly between the point 
sources at the Freeport facility and the point sources at the Asarco 
facility, due to the substantial differences between the process flows 
and gas flows (including capture) at the Freeport facility and the 
process flows and gas flows (including capture) at the Asarco facility. 
Commenters also contended that the MACT standards for unregulated HAP 
are based on a single testing campaign; therefore, a representative 
MACT floor cannot be established. Commenters noted that additional 
performance testing of the unregulated HAP will be conducted at the 
Freeport facility in the fourth quarter of 2023 and first quarter of 
2024, and they asked that the EPA allow for submittal and consideration 
of these data (which they said they will be able to provide at least 
several weeks prior to the May 4, 2024, deadline for final rule 
publication) when establishing limits in the final rule. In the absence 
of additional data, commenters believe that a representative MACT floor 
cannot be established, and any regulatory action should be postponed or 
limited to workplace standards.
    Response: The proposed unregulated HAP standards were developed 
based on the 99 percent UPL of the available emissions data for this 
source category, which included data collected through the 2022 section 
114 information request to Freeport. The testing associated with 
Freeport's section 114 information request response was

[[Page 41679]]

conducted using the EPA prescribed test methods, and the results were 
reviewed by EPA measurement experts upon submission. We did not find 
equivalent data from Asarco in the administrative record. Nevertheless, 
the EPA is allowed to and required to establish MACT standards for a 
source category based on sources for which we have emissions data; 
thus, the data for Freeport must be used for the source category in the 
absence of data from Asarco. The 3 data points we used to set the floor 
are the minimum sample size necessary to use the 99 percent UPL 
approach to develop a MACT standard. While we acknowledge this is a 
limited dataset, we followed the EPA protocol for developing MACT from 
limited datasets which was described in Appendix B of the Proposed 
Maximum Achievable Control Technology (MACT) Floor Analysis for 
Unregulated HAP for the Primary Copper Smelting Major Source Category 
memorandum (Docket ID No. EPA-HQ-OAR-2020-0430-0153); therefore, we 
disagree that we have insufficient data to develop numerical emission 
standards based on the MACT floor.
    As described in section IV.C.3.c. of this preamble, we note that we 
received an additional test report for these non-metal HAPs on January 
29, 2024, well after close of the public comment period (i.e., 
September 22, 2023). However, for the reasons described in section 
IV.C.3.c., we did not incorporate these new data in our analyses to 
establish revised standards for the final rule. Therefore, we are 
promulgating the MACT floor emission standards for these unregulated 
HAP, as proposed.
    Comment: Commenters agreed with the EPA's conclusion that the BTF 
options for controlling unregulated HAP are not cost effective. They 
also noted these control options, which include the use of ACI and DSI 
in combination with the aisle scrubber, are not technically feasible. 
Commenters noted that the aisle scrubber is a wet scrubber designed for 
acid gas control, and the use of either ACI or DSI would require a 
high-efficiency particulate control device such as a baghouse to 
collect the injected material. The commenter stated that the addition 
of a baghouse would significantly increase control costs for the 
pollutants, making the cost effectiveness of their control poorer. With 
regards to HCl and Cl, commenters stated the EPA's estimated emissions 
reductions of 98 percent for these pollutants using DSI injection is 
not practical given their already efficient removal by the aisle 
scrubber and thus already very low stack concentrations. DSI could not 
be expected to reduce emissions of these pollutants by more than 20 
percent and could potentially result in 0 percent emission reduction.
    Response: As described elsewhere in this preamble, we are 
promulgating a combined emission standard for the combination of 
exhaust streams from the anode refining department and the Hoboken 
converter process fugitive capture system. At the Freeport facility, 
the anode refining department and the Hoboken converter process 
fugitive capture system exhaust streams combine in the aisle scrubber 
from which they are emitted to the atmosphere. The Freeport facility 
controls the anode refining department emissions with a baghouse prior 
to routing the exhaust to the aisle scrubber. We expect that the 
combined standard we are promulgating in this action will require the 
installation of a baghouse to control the emissions stream from the 
Hoboken converter process fugitive capture system. Therefore, the costs 
for a primary particulate control device of the emission streams which 
combine in the aisle scrubber will be incurred to comply with the 
combined emission standard. As discussed in section IV.C.4.b., in 
response to comments for this rulemaking we are amending our cost 
estimates included in the 2023 supplemental proposal for controlling 
these unregulated HAP to include installation and indirect costs 
including contingency as well as to address comments regarding the 
sizing of these injection systems. We continue to expect that DSI/ACI 
systems would be required to provide control for these pollutants, and, 
thus, our revised estimates continue to represent the incremental costs 
of adding these systems to an existing control device, which will now 
be the baghouse required for compliance with other requirements in this 
final rulemaking. As noted in our previous discussion of the baghouse 
for the Hoboken converter process fugitive capture system, the baghouse 
receives about 75 percent of the loading to the aisle scrubber. The 
performance test results which were used to inform the emission 
standards and to quantify emission reductions of the unregulated HAP 
(i.e., benzene, D/F, HCl, chlorine, PAH (including naphthalene), and 
toluene) were conducted at the outlet of the aisle scrubber. Therefore, 
we are revising our emission reduction estimates provided in the 2023 
supplemental proposal to be based on the expected loading to the 
baghouse (i.e., 75 percent of the emission rates from the aisle 
scrubber outlet). Concerning the control efficiency applied to HCl and 
Cl emissions, we note that the measurements of emission rates were 
taken at the outlet of the aisle scrubber. The aisle scrubber is 
designed to reduce acid gases including HCl and Cl; therefore, we agree 
with commenters that assuming an additional 98 percent reduction of the 
emission rates at the aisle scrubber in our BTF evaluation is likely 
technically infeasible. In reviewing the data for HCl, we note that the 
99 percent UPL was less than 3 times the representative detection limit 
(3xRDL), thus the emission standard was set at 3xRDL consistent with 
EPA emission standard development procedures. Therefore, it is 
infeasible to measure lower levels of HCl and we are no longer 
considering BTF options for this pollutant. However, we have revised 
our estimated emission reductions for Cl to assume a 20 percent 
reduction. The revisions to the expected quantity of emission 
reductions and our cost estimates result in increased cost 
effectiveness for these unregulated HAP. For chlorine, benzene, 
toluene, and PAH, the cost effectiveness ranges from $8.1 million/ton 
HAP reduced to $120 million/ton of HAP reduced. For D/F, the cost 
effectiveness is $107 million/gram of HAP reduced. These revisions do 
not change our conclusion that the BTF costs for controlling these 
pollutants are unreasonable, and we are therefore promulgating the MACT 
floor standards. The details of our BTF analysis can be found in 
Estimated Cost for Beyond-the-floor Controls for HAP Emissions from 
Primary Copper Smelting Facilities--REVISED, which is available in the 
docket for this rulemaking.
    Comment: Commenters noted that the proposed standards for 
unregulated HAP are a function of concentrated ore fed, i.e., the 
emission limits are pounds per ton concentrated ore fed. Commenters 
stated that some of these compounds are not correlated with ore 
composition, but instead with natural gas consumption or impurities 
from third party copper scrap recycling. The commenters noted that 
additional performance testing should be conducted to inform whether 
other operating parameters influence emissions.
    Response: We used production-based thresholds to provide equitable 
emission standards for other facilities in the source category. No data 
was provided by FMMI indicating whether copper scrap was part of the 
feed during the performance tests which informed the emission 
standards. However, in light of the possibility that copper scrap was 
part of the feed during the tests conducted in response to the 2022

[[Page 41680]]

section 114 information request, we are changing the denominator from a 
concentrated ore fed basis to a copper concentrate feed charged to the 
smelting vessel basis, where ``copper concentrate feed'' is defined in 
40 CFR 63.1459.
d. What is the rationale for our final approach and final decisions for 
the unregulated HAP revisions made pursuant to CAA section 112(d)(2) 
and (3)?
    As discussed in the 2023 supplemental proposal, the EPA identified 
benzene, toluene, HCl, Cl, PAHs, and D/F in the major source category 
for which the 2002 major source NESHAP did not include standards. 
Except for HCl, the standards we are promulgating for unregulated HAP 
are MACT floor limits based on the 99 percent UPL. For HCl, the 99 
percent UPL was less than 3xRDL for HCl, therefore, consistent with EPA 
guidelines, the latter was used to set the MACT floor limit. As 
discussed in the 2023 supplemental proposal, the EPA evaluated BTF 
limits for each pollutant but did not propose them due to unreasonable 
costs. Therefore, consistent with the 2023 supplemental proposal, we 
are promulgating numerical emission standards for each unregulated HAP 
(i.e., benzene, D/F, HCl, chlorine, PAH excluding naphthalene, 
naphthalene, and toluene). We are also promulgating, as proposed, that 
compliance with these standards will be demonstrated by an initial 
performance test and subsequent performance testing at least once every 
5 years.
5. New Copper Converter Departments
a. What did we propose for the new copper converter departments 
pursuant to CAA section 112(d)(2) and (d)(3)?
    The EPA proposed in the 2022 proposal a MACT floor limit for new 
copper converters of 0.031 lbs of PM10 per ton of copper 
concentrate feed charged to the smelting vessel. We also proposed that 
compliance with the PM10 emissions limit for new copper 
converter departments will be demonstrated through an initial 
performance test followed by compliance test at least once per year.
b. How did the new copper converter departments revisions made pursuant 
to CAA section 112(d)(2) and (3) change since proposal?
    The proposed limit and compliance requirements were not changed.
c. What key comments did we receive on the proposed new copper 
converter departments revisions made pursuant to CAA section 112(d)(2) 
and (3) and what are our responses?
    The EPA did not receive notable comments on the proposed limit or 
proposed compliance requirements.
d. What is the rationale for our final approach and final decisions for 
the new copper converter departments revisions made pursuant to CAA 
section 112(d)(2) and (3)?
    As discussed in the 2022 proposal, the 2002 major source NESHAP 
current requirement for new converters is that the use of new batch 
copper converters is prohibited. Any new copper converters covered by 
the major source NESHAP would need to be continuous converters or some 
other currently unknown non-batch converter technology. However, the 
2002 major NESHAP did not include an emissions standard for new 
converters. Therefore, pursuant to CAA section 112(d)(2) and (3), the 
EPA is finalizing, as proposed in the 2022 proposal, the MACT floor 
limit for new copper converters of 0.031 lbs of PM10 per ton 
of copper concentrate feed charged to the smelting vessel and related 
compliance requirements. As discussed in the 2022 proposal, there are 
currently no existing continuous converters in the major source 
category, and therefore, we did not propose and are not finalizing an 
emission standard for existing continuous copper converters. Also as 
discussed in the 2022 proposal, since there are no existing continuous 
copper converters in the major source category, the PM10 
limit is based on the performance of the best similar source, which is 
the Kennecott primary copper smelting facility. We did not identify any 
cost-effective BTF options.

D. Final Rule Amendments Addressing Bypass Stack Emissions

1. What revisions did we propose for bypass stack emissions?
    We proposed in the 2023 supplemental proposal prohibiting the use 
of a bypass stack. We also proposed in the 2023 supplemental proposal a 
definition of ``bypass stack'' in 40 CFR 63.1459 and proposed that use 
of a bypass stack will result in a violation of the numerical emission 
standards contained in the Primary Copper Smelting NESHAP in 40 CFR 
63.1444. We proposed that the use of a bypass stack during a 
performance test will invalidate the test.
2. How did the bypass stack revisions change since proposal?
    Based on consideration of comments, the EPA is not prohibiting the 
use of a by-pass stack. Instead, EPA is promulgating a work practice 
standard pursuant to CAA section 112(h) to minimize HAP emissions 
vented through a bypass stack during planned maintenance events. We are 
promulgating work practices instead of an emissions limit because we 
determined it is not economically or technically feasible to complete 
valid PM compliance tests during these events. When it is infeasible to 
reliable conduct valid compliance tests, such as in this case, the CAA 
section 112(h) allows EPA to establish work practice standards instead 
of a numerical emissions limit.
    When the bypass stack is used, the process concentrate feed will be 
ceased, but pollution controls will remain operating until no copper is 
being processed by the converters. During these periods, a charge 
remains in the electric furnace to ensure the material remains molten, 
any additional emissions from the smelting process are nominal because 
the smelting furnace and converters are not operating, and a crust will 
form on the slag surface of the electric furnace minimizing flow rate 
and emissions. Only once the crust is formed, the bypass is then opened 
to vent residual gases prior to conducting maintenance. A CEMS for flow 
and SO2 or a PM detector at the duct for the bypass stack 
may be used, and data from the CEMS confirms the emissions during these 
planned maintenance activities are minimal. We are revising the 
definition of a bypass stack to reflect this approved purpose.
3. What key comments did we receive on the proposed bypass stack 
revisions and what are our responses?
    Comment: Several commenters supported the EPA's proposal to 
prohibit the use of bypass stacks, noting that a bypass stack is a 
negligent mechanism that promotes a reactive rather than a proactive 
approach to a facility's pollution. One user of bypass stacks disagreed 
with the proposal to eliminate their use, noting it is overly broad and 
ignores essential work practices designed to ensure the safe 
maintenance of process and pollution control equipment. The commenter 
noted that the bypass is used during maintenance and in particular 
prior to entering process vessels or confined spaces. In these 
instances, the commenter explained that the concentrate feed is ceased, 
but pollution

[[Page 41681]]

controls remain operating until no more copper is being processed by 
the converters. During these periods, a charge remains in the electric 
furnace to ensure the material remains molten, any additional emissions 
from the smelting process are nominal because the smelting furnace and 
converters are not operating, and a crust will form on the slag surface 
of the electric furnace minimizing emissions. The commenter further 
explained that the bypass is then opened to vent residual gases prior 
to conducting maintenance. The commenter noted that they operate a CEMS 
for flow and SO2 at the duct for the bypass stack, and data 
from this CEMS confirms the SO2 emissions during these 
maintenance activities are minimal. The commenter does not believe it 
is appropriate for the use of the bypass to be considered a violation 
of the numerical emission standards of the NESHAP or a bypass of the 
associated air pollution control devices (APCDs). In the maintenance 
periods when the bypass is used, emissions are expected to be small and 
below applicable limits, and air pollution control equipment is either 
not possible or unnecessary. The commenter recommended that the EPA 
promulgate work practice standards to regulate the use of the bypass. 
An additional comment was submitted after the comment period ended 
which also explained in more detail the challenges of testing the 
bypass stack siting zero or near zero velocities and volumetric flow 
rates at the stack.
    Response: The EPA has reviewed the information provided and we are 
establishing a work practice standard for use of the bypass stack to 
allow planned maintenance of the control devices and processes to be 
conducted safely. When the bypass stack is used, the work practice must 
be followed, and the smelting furnaces and converters must not be 
operating. The control devices will remain operational until a crust is 
formed on the slag and emissions are minimal. The HAP emission limits 
are on a concentrate feed basis and during the work practice standards 
the feed concentrate ceases so the HAP limit is not applicable. Since 
the bypass stack is only used in planned maintenance, flow rate and 
SO2 will be minimal but need to be monitored and emissions 
are expected to be minimal due to the low or lack of flow rate and when 
the work practice standards are implemented. We are finalizing the 
definition ``bypass stack'' in 40 CFR 63.1459. We are also finalizing 
that the use of a bypass stack during a performance test will 
invalidate the test. These conditions are consistent with the EPA's 
interpretation of the application of the court's decision in Sierra 
Club v. EPA, 551 F. 3d 1019 (D.C. Cir. 2008).
4. What is the rationale for our final approach and final decisions for 
bypass stack emissions?
    The EPA's rationale for allowing the use of a bypass stack is to 
ensure safety during essential planned maintenance events, and the 
approach being finalized ensures that applicable emission limits 
continue to be met. For this reason, we are promulgating the following 
work practice standard for the use of bypass stacks at Primary Copper 
Smelters:
    In the case of planned maintenance, feed to the IsaSmelt[supreg] 
Furnace must cease; power to the electric furnace must be lowered and a 
crust must be allowed to form on the surface of the slag; the operation 
of the converters must cease and the converters rolled out; and the 
operation of the anode vessels must cease. Once the main process units 
are shut down, residual process gases may be re-directed from the acid 
plant. If the fan to the anode refining point source baghouse is 
functioning, then the residual process gases must be redirected to the 
control device. If there is a shutdown or emergency shutdown event, the 
control devices should continue to run until process emissions cease. 
If the control devices are shut down before the process emissions cease 
and the bypass stack is used to vent to the process gas to the 
atmosphere, there will be a violation of the work practice standards. 
In addition to this work practice standard, we finalize, as proposed, 
that the use of a bypass stack is not permitted during compliance 
performance tests of the processes. We estimate that Freeport will not 
incur costs to comply with the final work practices because they are 
already implementing them at their facility.

E. Final Rule Amendments Addressing Compliance Dates

1. What compliance dates did we propose?
    In the 2022 proposal, the EPA proposed that existing facilities 
must comply with the anode refining point source limit within one year. 
In the supplemental proposal, we proposed a combined roofline PM 
emission limit with a compliance timeframe of 2 years following 
promulgation, and a 1-year compliance timeframe following promulgation 
for emission limits for mercury, HCl, chlorine, D/F, benzene, toluene, 
PAHs excluding naphthalene, and naphthalene. We also proposed in the 
supplemental proposal a compliance timeframe of 2 years following 
promulgation for the co-proposed options for the aisle scrubber at 
Freeport.
2. How did the compliance dates change since proposal?
    We are promulgating option 2 for the aisle scrubber at Freeport, 
which we expect will require the installation of PM controls (such as a 
baghouse) to control emissions from the Hoboken converter process 
fugitive capture system in order to comply with the emission standard 
(a combined PM limit at the aisle scrubber outlet). Option 2 is being 
promulgated pursuant to section 112(d)(6); therefore, we are revising 
its compliance date to 3 years following promulgation. We are also 
revising the compliance time for anode refining point sources. As 
discussed in section III.F., for anode refining point sources where the 
anode emissions are not combined with Hoboken converter process 
fugitive capture system emissions in an aisle scrubber, we are 
finalizing the proposed requirement that existing facilities must 
comply within 1 year after promulgation. For anode refining point 
sources that combine their anode emissions with Hoboken converter 
process fugitive capture system emissions in an aisle scrubber, 
compliance with the anode refining point source limit will be 
demonstrated through compliance with the combined PM limit at the aisle 
scrubber outlet and its associated compliance date.
3. What key comments did we receive on the proposed compliance dates 
and what are our responses?
    Comment: Commenters stated that the EPA should allow 3 years for 
compliance with the combined roofline PM emission limit. The commenters 
stated there are also significant practical reasons for a 3-year 
compliance period including the complex design and engineering of the 
most cost efficient and reliable combination of control options to 
achieve the targeted emission reductions. According to the commenters, 
the design and engineering involves multiple time-consuming steps to 
(i) assess the emission sources, (ii) evaluate the potential control 
options for effectiveness, reliability and cost, (iii) design 
engineering of the final scope, (iv) procurement in a current 
environment where supply issues are common, (v) construction, and 
finally (vi) startup, which will be challenging to accomplish in 3 
years, much less 2.
    Response: We acknowledge the complex nature of the engineering 
involved to evaluate the best controls to

[[Page 41682]]

use to comply with the final combine roofline PM standard, as well as 
the potential supply issues; however, the combined roofline PM emission 
limit is being promulgated pursuant to CAA section 112(f)(2), to 
address unacceptable risk. Section 112(f)(2) of the CAA allows up to 
two years after the effective date of a standard to comply if the 
Administrator finds it is necessary for the installation of controls.
4. What is the rationale for our final approach and final decisions for 
compliance dates?
    We are promulgating compliance times for the standards in the rule 
based on time frames allowed in CAA, which includes up to 2 years for 
section 112(f)(2), and up to 3 years for sections 112(d)(2) and (3), 
and 112(d)(6), along with our judgement of when the standards can be 
met. The final compliance dates are as follows:
     Three years within promulgation for meeting the combined 
PM limit for the anode point source emissions that are combined with 
Hoboken converter process fugitive capture system emissions;
     Three years within promulgation for meeting the anode 
refining point source standard for anode point source emissions that 
are combined with Hoboken converter process fugitive capture system 
emissions;
     One year within promulgation for meeting the anode 
refining point source standard for anode point source emissions that 
are not combined with Hoboken converter process fugitive capture system 
emissions; and
     Two years within promulgation for meeting the combined 
roofline PM emission limit;
     Three years within promulgation for meeting the combined 
roofline lead emission limit and design standards;
     One year within promulgation or meeting standards for 
mercury, HCl, chlorine, D/F, benzene, toluene, PAHs excluding 
naphthalene, and naphthalene; and
     180 days within promulgation for all other revisions 
including compliance with SSM revisions and bypass stack revisions.
    For new sources, all standards in the rule are effective 
immediately upon the effective date of the standard, or upon startup, 
whichever is later. We are finalizing a new table, table 4, in the 40 
CFR part 63, subpart QQQ, to provide the applicability and compliance 
dates for the new standards to assist facilities with determining these 
timeframes.

F. Other Major Comments

    Comment: A commenter stated that they understood the EPA's 
assertion that fenceline monitoring is not appropriate for this source 
category given roof top emissions would not be measured at the 
fenceline. The Commenter stated that HAP metals tend to deposit within 
a few miles of the facility and therefore suggested that EPA consider 
community monitoring similar to those proposed in the Ethylene Oxide 
Sterilizer Rule.
    Another commenter noted that the EPA's assertion that fenceline 
monitoring is not appropriate for this source category is refuted by 
EPA's air toxics standards for integrated iron and steel mills (``Steel 
Mills''), in which the agency finds that fugitive emissions come from 
heights of 100 feet or more and proposed fenceline monitoring. 
Alternatively to fenceline monitoring, the EPA could provide for 
monitors placed higher up, either on existing structures or structures 
built for the purpose but does not even discuss this possibility.
    Response: As stated in the 2023 supplemental proposal, we 
considered the possibility of a fenceline monitoring requirement and 
determined that it is not appropriate for this source category. When 
considering whether fenceline monitoring was appropriate for this 
source category, we examined the potential for fugitive HAP emissions 
to be significant, particularly at or near ground level, and whether 
there are measurement capabilities for the expected pollutants to be 
monitored, in this case lead and/or arsenic. For this source category, 
we did not identify any significant sources of ground level emissions. 
Other considerations included whether there are similar sources located 
at facilities in other source categories where fenceline monitoring is 
already being conducted. For example, we recognize that one similarity 
between integrated iron and steel facilities and primary copper 
facilities is that both source categories have fugitive metal HAP 
emissions from roof vents, and as mentioned by the commenter, EPA is 
requiring fenceline monitoring of chromium at the II&S facilities. 
However, there are also important differences. First, we are 
promulgating process fugitive numeric emission limits for the roofline 
vents at major source primary copper smelters and requirements for 
annual compliance testing of the roofline vents at these sources. In 
contrast, the integrated iron and steel final rule (89 FR 23294, April 
3, 2024) did not include numeric emission limits for the roofline vents 
and does not require any emissions testing from the roof vents (other 
than opacity readings). Instead, in the Integrated Iron and Steel 
NESHAP, the EPA finalized the following: (1) work practice standards 
for the basic oxygen process furnaces (BOPFs), Bell Leaks (charging 
operation) and beaching; and (2) opacity limits for slag processing and 
planned bleeder valve openings. Secondly, we note that some of the 
sources of fugitive emissions at integrated iron and steel are at 
ground level such as slag processing and beaching. We have not 
identified any significant sources of ground level fugitive emissions 
at the primary copper smelters. Furthermore, regarding fugitive 
emissions from the roof vents, unlike Primary Copper facilities (for 
which we have test data and will obtain future test data through 
emissions testing requirements), we have no emissions test data from 
roof vents at integrated iron and steel (II&S) facilities. Therefore, 
in the integrated iron and steel rulemaking, fenceline monitoring for 
chromium was proposed and finalized to ensure that the work practices 
and opacity limits for these unmeasured fugitive and particulate 
emissions sources at integrated iron and steel facilities are achieving 
the anticipated reductions.
    In addition, we disagree with the commenter's suggestion to place 
monitors at an elevated height. Fenceline ambient air monitors are 
typically used to monitor the potential exposure of nearby communities 
to ground level pollutant emissions; therefore, placing monitors at a 
height higher than the standard 1.5 meters (the breathing zone) would 
not be appropriate.
    Furthermore, there are lead monitors and arsenic monitors already 
in the surrounding community nearby the major source facilities, and, 
as stated in the 2022 proposal, Utah Division of Air Quality (UDAQ), 
conducted lead ambient monitoring near the area source facility 
(Kennecott) from January 2010 through June 2017. With EPA's 
concurrence, this lead monitor was shutdown after UDAQ was able to 
demonstrate that the likelihood of violating the NAAQS for lead was so 
low that it was no longer necessary to monitor.
    We maintain in the final rule, as stated in the 2023 supplemental 
proposal, that these characteristics suggest that fenceline 
monitoring-- which is typically used to detect emissions that can be 
difficult to control or measure at the points where they are emitted, 
and to identify the need for follow-up investigation and corrective 
action--would have relatively limited

[[Page 41683]]

value in the context of this primary copper smelting source category.
    We also note that while the EPA's EtO Sterilizers proposal 
requested comment on the appropriateness of community monitoring, EPA 
did not propose or finalize fenceline or ambient air monitoring 
requirements in the EtO Sterilizers rule (88 FR 22790, April 13, 2023; 
89 FR 24090, April 5, 2024).
    Comment: A commenter stated that process fugitive emissions 
captured and ducted to a baghouse, emissions from the secondary capture 
system for the converter department and the anode refining department 
or the alternative proposed baghouse-based emissions from the converter 
department should be monitored by PM CEMS to ensure compliance.
    Response: The EPA has included PM CEMS as an option for continued 
compliance in the final rule. Either an operating parameter established 
during the performance test or PM CEMS will be utilized to demonstrate 
continued compliance.

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

A. What are the affected facilities?

    The Primary Copper Smelting source category includes any facility 
that uses a pyrometallurgical process to extract copper from copper 
sulfur ore concentrates, native ore concentrates, or other copper 
bearing minerals. There are currently 3 copper smelting facilities: 2 
are major sources and 1 is an area source. No new copper smelting 
facilities are currently being constructed or are planned in the near 
future.
1. 40 CFR Part 63, Subpart QQQ
    The affected sources subject to 40 CFR part 63, subpart QQQ, the 
major source NESHAP, are copper concentrate dryers, smelting furnaces, 
slag cleaning vessels, copper converter departments, and fugitive 
emission sources.
2. 40 CFR Part 63, Subpart EEEEEE
    Under 40 CFR part 63, subpart EEEEEE, the area source NESHAP, the 
affected sources are copper concentrate dryers, smelting vessels, 
converting vessels, matte drying and grinding plant, secondary gas 
systems, anode refining furnaces, and anode shaft furnaces.

B. What are the air quality impacts?

    The final amendments in this action would achieve about 8.0 tpy 
(7.99 tpy rounded) reduction of HAP metals emissions (primarily lead, 
arsenic, cadmium) from process fugitives associated with roofline vents 
and emissions from the aisle scrubber (combined primary emissions from 
anode refining department and emissions from the Hoboken converter 
process fugitive capture system). In this action, we are also 
finalizing additional work practices that we estimate will achieve some 
additional unquantified HAP emissions reductions. These final 
amendments will also reduce risks to public health and the environment, 
as described above in this preamble.
    Furthermore, we are finalizing new standards for mercury, benzene, 
toluene, HCl, chlorine, PAH, and dioxins/furans. We do not expect to 
achieve reductions in emissions with these new standards. However, 
these standards will ensure that the emissions remain controlled and 
minimized moving forward. The final amendments also include removal of 
the SSM exemptions.

C. What are the cost impacts?

    As described above, the PM standard for the combined emissions from 
roofline vents would require additional controls to be installed at the 
Freeport facility. We estimate capital costs of $10.2 million and total 
annual costs of $2.3 million (includes annual testing costs) for 
Freeport (2022 dollars). Total annual costs include annualized capital 
costs, annual operating and maintenance costs, and annual testing 
costs. Additionally, we estimate that the Freeport facility will need 
to install additional controls to comply with the emission limit for 
the combined gas stream including the anode refining point source and 
the Hoboken converter process fugitive capture system. We estimate 
capital costs of $59.5 million and total annual costs of $10.8 million 
will be incurred by Freeport. The Asarco facility will need to install 
additional controls to comply with the design standards and lead 
emission limit in this final rule. We estimate capital costs of $15.4 
million and total annual costs (including testing) of $3.9 million will 
be incurred by Asarco.
    We expect that both Asarco and Freeport will incur additional costs 
for compliance testing. The estimated annual costs for performance 
testing of the previously unregulated HAP are $87,980 for the Freeport 
facility and $113,340 for the Asarco facility. The estimated annual 
costs for compliance testing for the anode refining point source and 
roofline PM emissions standards for the Asarco facility is $138,157.
    The total annual costs of all the final requirements (i.e., 
annualized capital, annual operating and maintenance, and annual 
emissions testing costs) are estimated to be about $17.3 million. The 
total capital costs of the final rule are estimated to be about $85.1 
million.

D. What are the economic impacts?

    The economic impacts associated with this final rule were estimated 
over an 8-year time frame from 2024 to 2031 using 3 percent and 7 
percent discount rates. The present value (PV) of the estimated costs 
of this final rule, discounted at a 7 percent rate over the 2024 to 
2031 period, is $139 million in 2022 dollars. The equivalent annual 
value (EAV) of the estimated costs is $23 million at a 7 percent 
discount rate. At a 3 percent discount rate, the PV and EAV of the cost 
impacts are estimated to be $146 million and $21 million, respectively. 
This final rule does not impact any small entities.
    This final rule is not expected to have significant impacts on 
domestic copper production; the market price for commercial grade 
copper or any products comprised of copper inputs; or employment, for 
several reasons. First, the estimated annual costs of this final rule 
are expected to be small compared to the potential annual revenues of 
the U.S. primary copper smelting industry. For example, the U.S. 
Geological Survey (USGS) estimates 2020 primary copper smelter 
production was 315,000 mt.\7\ Applying an export price for 
unmanufactured anodes and blister of $5,400 per mt that year, industry 
revenues in 2020 would have been an estimated $1.7 billion.\8\ The 
estimated annual costs of the final rule ($18 million) represent about 
one percent of this 2020 annual revenue estimate. Additionally, the 
affected companies are accustomed to spending large sums on annual 
maintenance. The 2022 annual report for Freeport-McMoran noted that 
they spent $87 million on annual maintenance in 2021 at the Miami 
smelter.\9\ The estimated annual costs of this final rule for this 
Freeport facility are $13 million, which is much lower than those 
maintenance expenditures. In addition, Freeport benefits from 
integrating its mining operations with its smelter. By being vertically 
integrated, Freeport is able to insulate itself from volatility in the 
cost of

[[Page 41684]]

smelting relative to a scenario where it outsources the smelting 
process. For this reason, the EPA expects that Freeport's incentive to 
maintain its smelting operation may extend beyond the margins earned 
solely on the smelting process. The EPA expects that Freeport can 
comply with this rule while continuing to operate its smelter at a 
similar capacity as it would under baseline conditions. Finally, due to 
trade exposure and the commodified nature of copper products (i.e., the 
interchangeability of copper products manufactured by different 
producers), the EPA expects that the affected companies are price 
takers, and thus we would not expect price impacts due to this final 
rule. The complete economic analysis can be found in the memorandum 
Economic Impact Analysis for the Final Residual Risk and Technology 
Review of the National Emission Standards for Hazardous Air Pollutants 
for Primary Copper Smelting Sources, available in the docket.
---------------------------------------------------------------------------

    \7\ See U.S. Geological Survey. Copper Statistics and 
Information. National Minerals Information Center. Annual 
Publication for 2020. Available at: https://www.usgs.gov/centers/national-minerals-information-center/copper-statistics-and-information. Note that 2020, which was a year of relatively low 
production compared to previous years is the most recent year for 
which USGS has this information available.
    \8\ Ibid.
    \9\ Freeport -McMoran. 2022 Annual Report. Available at: https://s22.q4cdn.com/529358580/files/doc_financials/annual/AR_2022.pdf.
---------------------------------------------------------------------------

E. What are the benefits?

1. 40 CFR Part 63, Subpart QQQ
    As described above, the final amendments would result in 
significant reductions in emissions of HAP metals, especially lead and 
arsenic. Both lead and arsenic are persistent bioaccumulative toxic 
(PBT) HAPs and developmental toxicants, with particular impacts on 
infants, children and the developing fetus. The final amendments will 
reduce risk from the source category to acceptable levels and ensure 
the NESHAP provides an ample margin of safety to protect public health. 
The benefits associated with the emission reductions were not able to 
be monetized but include reductions in both cancer and noncancer (e.g., 
developmental) endpoints. Some unquantified benefits of these 
amendments will accrue to Tribal nations living in proximity to these 
facilities; the reduction in cancer and non-cancer risks due to 
emissions of PBT HAP metals will benefit Tribal and other communities 
overburdened by air pollution. The final amendments also revise the 
standards such that they apply at all times, which includes SSM 
periods. Furthermore, the final requirements to submit reports and test 
results electronically will improve monitoring, compliance, and 
implementation of the rule.
2. 40 CFR Part 63, Subpart EEEEEE
    The final amendments under 40 CFR part 63, subpart EEEEEE, revise 
the standards such that they apply at all times, which includes SSM 
periods. Furthermore, the final requirements to submit reports and test 
results electronically will improve monitoring, compliance, and 
implementation of the rule.

F. What analysis of environmental justice did we conduct?

    For purposes of analyzing regulatory impacts, the EPA relies upon 
its June 2016 Technical Guidance for Assessing Environmental Justice in 
Regulatory Analysis, which provides recommendations that encourage 
analysts to conduct the highest quality analysis feasible, recognizing 
that data limitations, time, resource constraints, and analytical 
challenges will vary by media and circumstance. The Technical Guidance 
states that a regulatory action may involve potential environmental 
justice (EJ) concerns if it could: (1) create new disproportionate 
impacts on communities with EJ concerns; (2) exacerbate existing 
disproportionate impacts on communities with EJ concerns; or (3) 
present opportunities to address existing disproportionate impacts on 
communities with EJ concerns through this action under development.
    The EPA's EJ technical guidance states that ``[t]he analysis of 
potential EJ concerns for regulatory actions should address three 
questions: (A) Are there potential EJ concerns associated with 
environmental stressors affected by the regulatory action for 
population groups of concern in the baseline? (B) Are there potential 
EJ concerns associated with environmental stressors affected by the 
regulatory action for population groups of concern for the regulatory 
option(s) under consideration? (C) For the regulatory option(s) under 
consideration, are potential EJ concerns created or mitigated compared 
to the baseline?'' \10\
---------------------------------------------------------------------------

    \10\ Technical Guidance for Assessing Environmental Justice in 
Regulatory Analysis, U.S. EPA, June 2016. Quote is from section 3--
Key Analytic Considerations, page 11.
---------------------------------------------------------------------------

    The environmental justice analysis is presented for the purpose of 
providing the public with as full as possible an understanding of the 
potential impacts of this final action. The EPA notes that analysis of 
such impacts is distinct from the determinations finalized in this 
action under CAA section 112, which are based solely on the statutory 
factors the EPA is required to consider under that section.
    To examine the potential for Environmental Justice concerns, the 
EPA conducted a baseline proximity analysis, baseline risk-based 
analysis (i.e., before implementation of any controls proposed by this 
action), and post-control risk-based analysis (i.e., after 
implementation of the controls proposed by this action) for the 
Freeport facility (tables 4 and 5). The total population, population 
percentages, and population count for each demographic group for the 
entire U.S. population are shown in the column titled ``Nationwide 
Average'' in tables 4 and 5 of this preamble. These national data are 
provided as a frame of reference.
BILLING CODE 6560-50-P

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BILLING CODE 6560-50-C
    The baseline proximity demographic analysis is an assessment of 
individual demographic groups in the total population living within 5 
km (~3.1 miles) and 50 km (~31 miles) of the facility. Approximately 
32,300 and 6,600 people live within 50km and 5 km, respectively of the 
Freeport facility. The results of the proximity demographic analysis 
indicate that the percent of the population that is Hispanic or Latino 
and that is American Indian or Alaska Native is higher than the 
corresponding national averages. This is particularly true for the 
population within 50km, which is 24 percent American Indian or Alaska 
Native, which is significantly above the 0.6 percent national average. 
The percent of people living below the poverty level and percent of 
people over the age of 25 without a high school diploma are also higher 
than the national averages.
    The risk-based demographic analysis focused on the populations 
living within 5 km (~3.1 miles) and 50 km of the Freeport facility with 
estimated cancer risks greater than or equal to 1-in-1 million and 
greater than or equal to 10-in-1 million resulting from Primary Copper 
Smelting source category emissions. The baseline risk analysis 
indicated that emissions from the source category, prior to controls in 
this action, expose 6,600 people living within 5 km and 21,900 people 
living within 50 km to a cancer risk greater than or equal to 1-in-1 
million, and 1,500 people living within 5 km and 4,600 people living 
within 50 km to a cancer risk greater than or equal to 10-in-1 million. 
The post-control risk-based demographic analysis, which is an 
assessment of risks to individual demographic groups in the population 
living within 5 km and 50 km of the facilities after implementation of 
the controls in this action (``post-control''), indicated that post-
control emissions from the source category expose 6,600 people living 
within 5 km and 16,000 people living within 50 km to a cancer risk 
greater than or equal to 1-in-1 million and 150 people living within 5 
km and 150 people living within 50 km to a cancer risk greater than or 
equal to 10-in-1 million.
    The demographics of the population living within 5 km with baseline 
cancer risks greater than or equal to 1-in-1 million is the same as the 
total population living within 5 km (i.e., all individuals living 
within 5 km have a baseline cancer risk greater than or equal to 1-in-1 
million). Also, since the controls do not reduce the number of 
individuals living within 5km with risks greater than or equal to 1-in-
1 million, the post-control demographics are also the same as the 
baseline. The demographics of the population living within 5 km with 
baseline and post-control cancer risks greater than or equal to 10-in-1 
million indicates that the percentage of the population that is 
Hispanic or Latino, living below the poverty level, over 25 without a 
high school diploma and in linguistic isolation are significantly above 
the corresponding national averages. However, the number of individuals 
exposed to post-control risks greater than or equal to 10-in-1 million 
is reduced by a factor of 10 for each demographic.
    The demographics of the population living within 50 km with 
baseline cancer risks greater than or equal to 1-in-1 million indicates 
that the percentage of the population that is American Indian or Alaska 
Native, Hispanic or Latino, living below the poverty level, over 25 
without a high school diploma and in linguistic isolation are 
significantly above the corresponding national averages. The 
demographics of the population living within 50 km with post-control 
cancer risks greater than or equal to 1-in-1 million indicates that the 
percentage of the population that is Hispanic or Latino, living below 
the poverty level, over 25 without a high school diploma and in 
linguistic isolation are significantly above the corresponding national 
averages. The percentage of the population that is American Indian or 
Alaska Native with post-control cancer risks greater than or equal to 
1-in-1 million dropped significantly from 24 percent to 4 percent, with 
the number of American Indian or Alaska Native individuals at this risk 
level dropping from 5,700 in the baseline to 640 post-control.
    The demographics of the population living within 50 km with 
baseline cancer risks greater than or equal to 10-in-1 million 
indicates that the percentage of the population that is Hispanic or 
Latino is significantly above the national average. The percentage of 
the population that is living below the poverty level or over 25 
without a high school diploma are closer to the national averages. The 
number of individuals living within 50 km exposed to post-control risks 
greater

[[Page 41688]]

than or equal to 10-in-1 million is reduced by about a factor of 30 for 
each demographic.
    The EPA provided meaningful participation opportunities for 
communities with environmental justice concerns. The EPA proposed the 
Primary Copper Smelting NESHAP in January 2022, and received comments, 
and published a supplemental proposal in July of 2023, and received 
additional comments. Communities with environmental justice concerns 
had the opportunity to comment and request public hearings in response 
to both proposals. The EPA received a combined comment from the San 
Carlos Apache Tribe, Sierra Club, and Earthjustice; comment from The 
National Tribal Air Association; a combined comment from several non-
governmental organizations including but not limited to the Allergy and 
Asthma Network and the Children's Environmental Health Network. Section 
IV. of this preamble provides a summary of key comments and responses. 
For all comments not discussed in this preamble, comment summaries and 
the EPA's responses can be found in the National Emission Standards for 
Hazardous Air Pollutant Emissions: Primary Copper Smelting Residual 
Risk and Technology Review and Primary Copper Smelting Area Source 
Technology Review: Summary of Public Comments and Responses document, 
available in the docket for this action (Docket ID No. EPA-HQ-OAR-2020-
0430). In addition to the response to comments, the EPA conducted 
outreach with potentially affected communities by participating in the 
National Tribal Air Association calls and conducted Tribal 
consultations during this rule making process. We believe this final 
action will reduce adverse human health or environmental effects on 
communities with environmental justice concerns and that the EPA 
provided meaningful participation opportunities for these communities 
to participate in the development of this action.

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 Orders 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is a ``significant regulatory action'' as defined in 
Executive Order 12866, as amended by Executive Order 14094. 
Accordingly, the EPA submitted this action to the Office of Management 
and Budget (OMB) for Executive Order 12866 review. Documentation of any 
changes made in response to the Executive Order 12866 review is 
available in the docket. The EPA prepared an economic analysis of the 
potential impacts associated with this action. This analysis, Economic 
Impact Analysis for the Final Residual Risk and Technology Review of 
the National Emission Standards for Hazardous Air Pollutants for 
Primary Copper Smelting Sources, is also available in the docket.

B. Paperwork Reduction Act (PRA)

1. 40 CFR Part 63, Subpart QQQ
    The information collection activities in this final rule have been 
submitted for approval to OMB under the PRA. The ICR document that the 
EPA prepared has been assigned OMB Control Number 2060-0476 and EPA ICR 
number 1850.10. You can find a copy of the ICR in the docket for this 
action, and it is briefly summarized here. The information collection 
requirements are not enforceable until OMB approves them.
    In this action, we are finalizing amendments that require 
electronic reporting of results of performance tests and CEMS 
performance evaluations, fugitive dust plans and notification of 
compliance reports, remove the requirement to submit certain 
information related to the malfunction exemption, and impose other rule 
revisions that affect reporting and recordkeeping requirements for 
primary copper smelting facilities, such as requirements to submit new 
performance test reports and to maintain new operating parameter 
records to demonstrate compliance with new standards. This information 
will be collected to assure compliance with 40 CFR part 63, subpart 
QQQ.
    Respondents/affected entities: Owners or operators of primary 
copper smelting facilities. Respondent's obligation to respond: 
Mandatory (40 CFR part 63, subpart QQQ).
    Estimated number of respondents: Two (total). Frequency of 
response: Initial, semiannual, and annual.
    Total estimated burden: The annual recordkeeping and reporting 
burden for facilities to comply with all of the requirements in the 
NESHAP is estimated to be 6,500 hours (per year). Burden is defined at 
5 CFR 1320.3(b).
    Total estimated cost: The annual recordkeeping and reporting burden 
for facilities to comply with all of the requirements in the NESHAP is 
estimated to be $860,000 (per year), of which $150,000 is for this 
rule, and $710,000 is for the other costs related to continued 
compliance with the NESHAP.
    There are no annualized capital costs. There are an estimated 
$302,000 in operation & maintenance costs associated with periodic 
performance testing.
    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 Agency 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 contained in this final rule.
2. 40 CFR Part 63, Subpart EEEEEE
    The information collection activities in this final rule have been 
submitted for approval to OMB under the PRA. The ICR document that the 
EPA prepared has been assigned EPA ICR number 2240.09. You can find a 
copy of the ICR in the docket for this action, and it is briefly 
summarized here. The information collection requirements are not 
enforceable until OMB approves them.
    In this action, we are finalizing amendments that require 
electronic reporting of results of performance tests and CEMS 
performance evaluations and notification of compliance reports, remove 
the malfunction exemption, and impose other revisions that affect 
reporting and recordkeeping for primary copper smelting facilities. 
This information will be collected to assure compliance with 40 CFR 
part 63, subpart EEEEEE.
    Respondents/affected entities: Owners or operators of primary 
copper smelting facilities. Respondent's obligation to respond: 
Mandatory (40 CFR part 63, subpart EEEEEE).
    Estimated number of respondents: One (total).
    Frequency of response: Initial, semiannual, and quarterly.
    Total estimated burden: The annual recordkeeping and reporting 
burden for facilities to comply with all of the requirements in the 
NESHAP is estimated to be 15 hours (per year). Burden is defined at 5 
CFR 1320.3(b).
    Total estimated cost: The annual recordkeeping and reporting burden 
for facilities to comply with all of the requirements in the NESHAP is 
estimated to be $1,973 (per year).
    There are no annualized capital or operation and maintenance costs.

[[Page 41689]]

    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 Agency 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 contained in this final rule.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. This 
action will not impose any requirements on small entities. Based on the 
Small Business Administration size category for this source category, 
no small entities are subject to this action.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate as described in 
UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect 
small governments. The action imposes no enforceable duty on any State, 
local, or Tribal governments or the private sector.

E. Executive Order 13132: Federalism

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

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

    This action does not have Tribal implications as specified in 
Executive Order 13175. The Executive order defines Tribal implications 
as ``actions that have substantial direct effects on one or more Indian 
tribes, on the relationship between the Federal Government and Indian 
tribes, or on the distribution of power and responsibilities between 
the Federal Government and Indian tribes''. Based on all of our 
analyses, we conclude that the amendments in this action will not have 
a substantial direct effect on one or more Tribes, change the 
relationship between the Federal Government and Tribes, or affect the 
distribution of power and responsibilities between the Federal 
Government and Indian Tribes. Thus, Executive Order 13175 does not 
apply to this action.
    Although this action does not have Tribal implications as defined 
by Executive Order 13175, consistent with the EPA policy on 
coordination and consultation with Indian Tribes, the EPA offered 
government-to-government consultation with Tribes during the rulemaking 
process. The EPA held a consultation with the San Carlos Apache Tribe 
on June 7, 2022, to discuss the 2022 proposal (Docket ID No. EPA-HQ-
OAR-2020-0430-0185) and ensure that the views of the San Carlos Apache 
Tribe were taken into consideration in the rulemaking process in 
accordance with the EPA Policy on Consultation with Indian Tribes 
(December 2023). The EPA Policy on Consultation with Indian Tribes is 
available in the docket for this action. The topics discussed during 
the consultation are described in the consultation request letter, 
dated April 4, 2022 (Docket ID No. EPA-HQ-OAR-2020-0430-0139). In 
addition, the EPA also received letters from representatives of the San 
Carlos Apache Tribe expressing their concerns due to emissions of lead 
and arsenic from the primary copper smelting facilities, which are 
available in the docket for this action. In the letter, dated September 
21, 2023 (which is available in the docket for this action), the Tribe 
requested consultation. We reached out to the Tribe on several 
occasions to schedule consultation but did not receive a response.

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

    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. This action's health and risk 
assessments are contained in sections III. and IV. of this preamble and 
further documented in the document titled Freeport Baseline and Control 
Options Re-model Risk Analysis Memo, which is available in the docket 
for this rule (Docket ID No. EPA-HQ-OAR-2020-0430).

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

    This action is not a ``significant energy action'' because it is 
not likely to have a significant adverse effect on the supply, 
distribution, or use of energy. We have concluded that this action is 
not likely to have any adverse energy effects because it contains no 
regulatory requirements that will have an adverse impact on 
productivity, competition, or prices in the energy sector.

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

    This rulemaking involves technical standards. Therefore, the EPA 
conducted searches for the 2022 proposal and 2023 supplemental proposal 
through the Enhanced NSSN Database managed by the American National 
Standards Institute (ANSI). The Agency also contacted VCS organizations 
and accessed and searched their databases. Searches were conducted for 
the EPA Methods 1, 1A, 2, 2A, 2C, 2D, 2F, 2G, 3, 3A, 3B, 4, 5, 5B, 5D, 
9, 17, 18, 22, 23, 26A, 29, 30A, and 30B of 40 CFR part 60, appendix A, 
and EPA Method 201A of 40 CFR part 51, appendix M. No applicable VCS 
were identified for EPA Method 1A, 2A, 2D, 2F, 2G, 5B, 5D, 22, 30A, 
30B, or 201A. During the searches, 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 
considered it as a potential equivalent method. All potential standards 
were reviewed to determine the practicality of the VCS for this rule. 
This review requires significant method validation data which meets the 
requirements of the 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. Four VCS were identified as an acceptable alternative to the EPA 
test methods for the purposes of this rule.
    The VCS ANSI/ASME PTC 19.10-1981 Part 10, Flue and Exhaust Gas 
Analyses, is an acceptable alternative to the EPA Method 3B manual 
portion only and not the instrumental portion. The ANSI/ASME PTC 19.10-
1981 Part 10 method incorporates both manual and instrumental 
methodologies for the determination of O2 content. The 
manual method segment of the O2 determination is performed 
through the absorption of O2. This VCS may be obtained from https://webstore.ansi.org/ or from the ANSI Headquarters at 1899 L Street NW, 
11th Floor, Washington, DC 20036.
    The VCS ASTM D7520-16, Standard Test Method for Determining the 
Opacity of a Plume in the Outdoor

[[Page 41690]]

Ambient Atmosphere, is an instrumental method to determine plume 
opacity in the outdoor ambient environment as an alternative to visual 
measurements made by certified smoke readers in accordance with EPA 
Method 9. The concept of ASTM D7520-16, also known as the Digital 
Camera Opacity Technique or DCOT, is a test protocol to determine the 
opacity of visible emissions using a digital camera. It was based on 
previous method development using digital still cameras and field 
testing of those methods. The purpose of ASTM D7520-16 is to set a 
minimum level of performance for products that use DCOT to determine 
plume opacity in ambient environments. The ASTM D7520-16 is an 
acceptable alternative to the EPA Method 9 with the following 
conditions:
    1. During the digital camera opacity technique (DCOT) certification 
procedure outlined in section 9.2 of ASTM D7520-16, you or the DCOT 
vendor must present the plumes in front of various backgrounds of color 
and contrast representing conditions anticipated during field use such 
as blue sky, trees, and mixed backgrounds (clouds and/or a sparse tree 
stand).
    2. You must also have standard operating procedures in place 
including daily or other frequency quality checks to ensure the 
equipment is within manufacturing specifications as outlined in section 
8.1 of ASTM D7520-16.
    3. You must follow the record keeping procedures outlined in 40 CFR 
63.10(b)(1) for the DCOT certification, compliance report, data sheets, 
and all raw unaltered Joint Photographic Experts Group (JPEG) files 
used for opacity and certification determination.
    4. You or the DCOT vendor must have a minimum of four (4) 
independent technology users apply the software to determine the 
visible opacity of the 300 certification plumes. For each set of 25 
plumes, the user may not exceed 15 percent opacity of anyone reading 
and the average error must not exceed 7.5 percent opacity.
    5. This approval does not provide or imply a certification or 
validation of any vendor's hardware or software. The onus to maintain 
and verify the certification and/or training of the DCOT camera, 
software and operator in accordance with ASTM D7520-16 and this letter 
is on the facility, DCOT operator, and DCOT vendor.
    The voluntary consensus standard ASTM D6420-99 (Reapproved 2010), 
Test Method for Determination of Gaseous Organic Compounds by Direct 
Interface Gas Chromatography/Mass Spectrometry, employs a direct 
interface gas chromatograph/mass spectrometer (GCMS) to identify and 
quantify the 36 volatile organic compounds (or sub-set of these 
compounds). This ASTM procedure has been approved by the EPA as an 
alternative to EPA Method 18 only when the target compounds are all 
known and the target compounds are all listed in ASTM D6420 as 
measurable.
    The VCS ASTM D6784-16, Standard Test Method for Elemental, 
Oxidized, Particle-Bound and Total Mercury Gas Generated from Coal-
Fired Stationary Sources (Ontario Hydro Method), is an acceptable 
alternative to the EPA Methods 101A and 29 (portion for mercury only) 
as a method for measuring mercury. This method applies to 
concentrations approximately 0.5-100 [mu]g/Nm3. This test method 
describes equipment and procedures for obtaining samples from effluent 
ducts and stacks, equipment and procedures for laboratory analysis, and 
procedures for calculating results.
    The ASTM standards are available from ASTM at https://www.astm.org 
or 1100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, telephone 
number: (610) 832-9500, fax number: (610) 832-9555 email address: 
[email protected].
    The searches conducted for the 2022 proposal and 2023 supplemental 
proposal identified 26 VCS that were potentially applicable for these 
rules in lieu of the EPA reference methods. After reviewing the 
available standards, the EPA determined that 26 candidate VCS (ASTM 
D3154-00 (2014), ASTM D3464-96 (2014), ASTM 3796-09 (2016), ASTM D3796-
90 (2004) ISO 10780:1994 (2016), ASME B133.9-1994 (2001), ISO 
10396:(2007), ANSI/ASME PTC 19-10-1981--Part 10 (2010) Flue and Exhaust 
Gas Analyses--Instrumental Procedure Only, ISO 12039:2001 (2012), ASTM 
D5835-95 (2013), ASTM D6522-11, CAN/CSA Z223.2-M86 (R1999), ISO 
9096:1992 (2003), ANSI/ASME PTC-38-1980 (1985), ASTM D3685/D3685M- 98-
13, CAN/CSA Z223.1-M1977, National Institute of Occupational Safety and 
Health (NIOSH) Method 2010 ``Amines, Aliphatic'', ASTM D6060-96 (2009), 
EN 1948-3 (2006), EN 1911-1,2,3 (1998), ASTM D6735-01 (2009), ISO 
10397:1993, ASTM D6331 (2014), EN13211:2001, CAN/CSA Z223.26-M1987, 
ASTM E1979-21, ASTM D4358-05) identified for measuring emissions of 
pollutants or their surrogates subject to emission standards in the 
rule would not be practical due to lack of equivalency, documentation, 
validation data and other important technical and policy 
considerations. Additional information for the VCS search and 
determinations can be found in the memorandums Voluntary Consensus 
Standard Results for National Emission Standards for Hazardous Air 
Pollutants: Primary Copper Smelting Residual Risk and Technology Review 
and Primary Copper Smelting Area Source Technology Review (Docket ID 
No. EPA-HQ-OAR-2020-0430-0065) and Voluntary Consensus Standard Results 
for National Emission Standards for Hazardous Air Pollutants: Primary 
Copper Smelting Residual Risk and Technology Review and Primary Copper 
Smelting Area Source Technology Review and Voluntary Consensus Standard 
Results for National Emission Standards of Hazardous Air Pollutants: 
Primary Copper Smelting Supplemental Proposal (Docket ID No. EPA-HQ-
OAR-2020-0430-0150), which are available in the docket for this action. 
Under 40 CFR 63.7(f) and 63.8(f), a source may apply to the EPA to use 
alternative test methods or alternative monitoring requirements in 
place of any required testing methods, performance specifications or 
procedures in the final rule or any amendments.
    The EPA is also incorporating by reference EPA/100/R-10/005, 
Recommended Toxicity Equivalence Factors (TEFs) for Human Health Risk 
Assessments of 2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin and Dioxin-Like 
Compounds, December 2010. This is the international method of 
expressing toxicity equivalents for dioxins/furans where a recommended 
toxicity equivalent factor (TEF) is multiplied by each individual 
compound's (congener) emission concentration to calculate the toxic 
equivalent quotient (TEQ). To estimate risk associated with the 
mixture, the dose-response function for the index chemical is evaluated 
at this sum, which is an estimate of the total index chemical 
equivalent dose for the mixture components being considered. This 
method may be obtained from https://www.epa.gov/sites/default/files/2013-09/documents/tefs-for-dioxin-epa-00-r-10-005-final.pdf. or U.S. 
Environmental Protection Agency, 1200 Pennsylvania Avenue NW, 
Washington, DC 20460, (202) 272-0167, https://www.epa.gov.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations and 
Executive Order 14096: Revitalizing Our Nation's Commitment to 
Environmental Justice for All

    The EPA believes that the human health or environmental conditions 
that

[[Page 41691]]

exist prior to this action result in or have the potential to result in 
disproportionate and adverse human health or environmental effects on 
communities with environmental justice concerns. The EPA evaluated the 
demographic characteristics of communities located near the major 
source facilities and determined that elevated cancer risks associated 
with emissions from these facilities disproportionately affect Native 
American, Hispanic, populations Below Poverty Level and Over 25 without 
High School Diploma individuals living nearby. As part of its 
environmental justice analysis, EPA evaluated whether the final action 
for the Primary Copper Smelting Major Source Category would address the 
existing disproportionately high and adverse human health effect on 
these individuals and EPA further evaluated the projected distribution 
of reductions in risk resulting from this action.
    The EPA believes that this action is likely to reduce existing 
disproportionate and adverse effects on communities with environmental 
justice concerns. The agency estimated the MIR at Freeport will be 
reduced from 70-in-1 million to 20-in-1 million and the population with 
cancer risks greater than or equal to 1-in-1 million will be reduced 
from 21,875 to 16,962 because of this action. We estimate that the 
maximum chronic noncancer inhalation TOSHI will be reduced from 1 to 
less than 1 (0.3), and the acute HQ will be reduced from a value of 7 
to 2 at Freeport. Given the uncertainties in the emissions data at 
Asarco and the short timeframe to complete the final rule, we did not 
evaluate the impact of the final standards on the population living in 
the vicinity of the Asarco facility. The standards in this final rule 
are estimated to reduce metal HAP emissions, primarily lead and 
arsenic, from this source category by 8.0 tpy.
    The methodology and the results of the demographic analysis are 
presented in section V.F. of this preamble and in the technical report 
Risk and Technology Review--Analysis of Demographic Factors for 
Populations Living Near Primary Copper Smelting Source Category 
Operations--Final Rule (Docket ID No. EPA-HQ-OAR-2020-0430). The 
information supporting this Executive order review is contained in 
section V.F. of this preamble.

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.

Michael S. Regan,
Administrator.

    For the reasons stated in the preamble, title 40, chapter I of the 
Code of Federal Regulations is amended 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 revising paragraphs (f)(1) and (i)(95), (105), 
and (110) and adding paragraph (o)(30) to read as follows:


Sec.  63.14  Incorporations by reference.

* * * * *
    (f) * * *
    (1) ANSI/ASME PTC 19.10-1981, Flue and Exhaust Gas Analyses [Part 
10, Instruments and Apparatus], issued August 31, 1981, IBR approved 
for Sec. Sec.  63.309(k); 63.365(b); 63.457(k); 63.772(e) and (h); 
63.865(b); 63.997(e); 63.1282(d) and (g); 63.1450(a), (b), (d), and (e) 
through (g); 63.1625(b); table 5 to subpart EEEE; Sec. Sec.  
63.3166(a); 63.3360(e); 63.3545(a); 63.3555(a); 63.4166(a); 63.4362(a); 
63.4766(a); 63.4965(a);63.5160(d); table 4 to subpart UUUU; table 3 to 
subpart YYYY; Sec. Sec.  63.7822(b); 63.7824(e); 63.7825(b); 
63.8000(d); 63.9307(c); 63.9323(a); 63.9621(b) and (c); 63.11148(e); 
63.11155(e); 63.11162(f); 63.11163(g); 63.11410(j); 63.11551(a); 
63.11646(a); 63.11945; table 4 to subpart AAAAA; table 5 to subpart 
DDDDD; table 4 to subpart JJJJJ; table 4 to subpart KKKKK; table 4 to 
subpart SSSSS; tables 4 and 5 to subpart UUUUU; table 1 to subpart 
ZZZZZ; table 4 to subpart JJJJJJ.
* * * * *
    (i) * * *
    (95) ASTM D6420-99 (Reapproved 2010), Standard Test Method for 
Determination of Gaseous Organic Compounds by Direct Interface Gas 
Chromatography-Mass Spectrometry, Approved October 1, 2010, IBR 
approved for Sec. Sec.  63.670(j); table 4 to subpart UUUU; 63.1450(f); 
63.7142(b); appendix A to this part.
* * * * *
    (105) ASTM D6784-16, Standard Test Method for Elemental, Oxidized, 
Particle-Bound and Total Mercury in Flue Gas Generated from Coal-Fired 
Stationary Sources (Ontario Hydro Method), Approved March 1, 2016; IBR 
approved for Sec. Sec.  63.1450(d); 63.9621; table 5 to subpart UUUUU; 
appendix A to subpart UUUUU.
* * * * *
    (110) ASTM D7520-16, Standard Test Method for Determining the 
Opacity of a Plume in the Outdoor Ambient Atmosphere, approved April 1, 
2016; IBR approved for Sec. Sec.  63.1450(c), (e), and (g); 63.1453(h); 
63.1625(b); table 3 to subpart LLLLL; Sec. Sec.  63.7823(c) through 
(e); 63.7833(g); 63.11423(c).
* * * * *
    (o) * * *
    (30) EPA/100/R-10/005, Recommended Toxicity Equivalence Factors 
(TEFs) for Human Health Risk Assessments of 2, 3, 7, 8-
Tetrachlorodibenzo-p-dioxin and Dioxin-Like Compounds, December 2010; 
IBR approved for Sec.  63.1459 and table 2 to subpart QQQ. (Available 
at https://www.epa.gov/sites/default/files/2013-09/documents/tefs-for-dioxin-epa-00-r-10-005-final.pdf.)
* * * * *

0
3. Effective July 15, 2024, further amend Sec.  63.14 by:
0
a. Revising paragraphs (f)(1) and (i)(110);
0
b. Redesignating paragraphs (o)(1) through (30) as paragraphs (o)(2) 
through (31); and
0
c. Adding new paragraph (o)(1).
    The revisions and addition read as follows:


Sec.  63.14  Incorporations by reference.

* * * * *
    (f) * * *
    (1) ANSI/ASME PTC 19.10-1981, Flue and Exhaust Gas Analyses [Part 
10, Instruments and Apparatus], issued August 31, 1981, IBR approved 
for Sec. Sec.  63.116(c); 63.116 and (h); 63.128(a); 63.145(i); 
63.309(k); 63.365(b); 63.457(k); 63.490(g); 63.772(e) and (h); 
63.865(b); 63.997(e); 63.1282(d) and (g); 63.1450(a), (b), and (e) 
through (g); 63.1625(b); table 5 to subpart EEEE; Sec. Sec.  
63.3166(a); 63.3360(e); 63.3545(a); 63.3555(a); 63.4166(a); 63.4362(a); 
63.4766(a); 63.4965(a); 63.5160(d); table 4 to subpart UUUU; table 3 to 
subpart YYYY; Sec. Sec.  63.7822(b); 63.7824(e); 63.7825(b); 
63.8000(d); 63.9307(c); 63.9323(a); 63.9621(b) and (c); 63.11148(e); 
63.11155(e); 63.11162(f);

[[Page 41692]]

63.11163(g); 63.11410(j); 63.11551(a); 63.11646(a); 63.11945; table 4 
to subpart AAAAA; table 5 to subpart DDDDD; table 4 to subpart JJJJJ; 
table 4 to subpart KKKKK; table 4 to subpart SSSSS; tables 4 and 5 to 
subpart UUUUU; table 1 to subpart ZZZZZ; table 4 to subpart JJJJJJ.
* * * * *
    (i) * * *
    (110) ASTM D7520-16, Standard Test Method for Determining the 
Opacity of a Plume in the Outdoor Ambient Atmosphere, approved April 1, 
2016; IBR approved for Sec. Sec.  63.1450(c), (e), and (g); 63.1453(h); 
63.1625(b); table 3 to subpart LLLLL; Sec. Sec.  63.7823(c) through 
(f), 63.7833(g); 63.11423(c).
* * * * *
    (o) * * *
    (1) EPA/100/R-10/005, Recommended Toxicity Equivalence Factors 
(TEFs) for Human Health Risk Assessments of 2, 3, 7, 8-
Tetrachlorodibenzo-p-dioxin and Dioxin-Like Compounds, December 2010; 
IBR approved for Sec.  63.1459 and table 2 to subpart QQQ. (Available 
at https://www.epa.gov/sites/default/files/2013-09/documents/tefs-for-dioxin-epa-00-r-10-005-final.pdf).
* * * * *

0
4. Revise subpart QQQ, consisting of Sec. Sec.  63.1440 through 
63.1459, to read as follows:
Subpart QQQ--National Emission Standards for Hazardous Air Pollutants 
for Primary Copper Smelting
Sec.
63.1440 What is the purpose of this subpart?
63.1441 Am I subject to this subpart?
63.1442 What parts of my plant does this subpart cover?
63.1443 When do I have to comply with this subpart?
63.1444 What emissions limitations, work practice standards, and 
design standards must I meet for my copper concentrate dryers, 
smelting vessels, slag cleaning vessels, copper converter 
departments, anode refining departments, process fugitive emissions 
from roofline vents, and bypass stacks?
63.1445 What work practice standards must I meet for my fugitive 
dust sources?
63.1446 What alternative emission limitation may I meet for my 
combined gas streams?
63.1447 What are my operation and maintenance requirements?
63.1448 What are my general requirements for complying with this 
subpart?
63.1449 By what dates must I conduct performance tests or other 
initial compliance demonstrations?
63.1450 What test methods and other procedures must I use to 
demonstrate initial compliance with the emission limitations and 
design standards?
63.1451 How do I demonstrate initial compliance with the emission 
limitations, work practice standards, design standards, and 
operation and maintenance requirements that apply to me?
63.1452 What are my monitoring requirements?
63.1453 How do I demonstrate continuous compliance with the emission 
limitations, work practice standards, design standards, and 
operation and maintenance requirements that apply to me?
63.1454 What notifications must I submit and when?
63.1455 What reports must I submit and when?
63.1456 What records must I keep and how long must I keep my 
records?
63.1457 What part of the general provisions apply to me?
63.1458 Who implements and enforces this subpart?
63.1459 What definitions apply to this subpart?
Table 1 to Subpart QQQ of Part 63--Applicability of General 
Provisions to This Subpart
Table 2 to Subpart QQQ of Part 63--Non-Mercury HAP Emission Limits
Table 3 to Subpart QQQ of Part 63--2010 Toxic Equivalency Factors 
(TEFs)
Table 4 to Subpart QQQ of Part 63--Compliance Dates for Amendments 
Being Promulgated on May 13, 2024
Figure 1 to Subpart QQQ of Part 63--Data Summary Sheet for 
Determination of Average Opacity

Subpart QQQ--National Emission Standards for Hazardous Air 
Pollutants for Primary Copper Smelting


Sec.  63.1440  What is the purpose of this subpart?

    This subpart establishes national emission standards for hazardous 
air pollutants (NESHAP) for primary copper smelters. This subpart also 
establishes requirements to demonstrate initial and continuous 
compliance with all applicable emission limitations, work practice 
standards, design standards, and operation and maintenance requirements 
in this subpart.


Sec.  63.1441  Am I subject to this subpart?

    You are subject to this subpart if you own or operate a primary 
copper smelter that is (or is part of) a major source of hazardous air 
pollutant (HAP) emissions on the first compliance date that applies to 
you (see Sec.  63.1443). Your primary copper smelter is a major source 
of HAP if it emits or has the potential to emit any single HAP at the 
rate of 10 tons or more per year or any combination of HAP at a rate of 
25 tons or more per year.


Sec.  63.1442  What parts of my plant does this subpart cover?

    (a) This subpart applies to each new and existing affected source 
at your primary copper smelter. The affected sources are each copper 
concentrate dryer, each smelting vessel, each slag cleaning vessel, 
each copper converter department, each anode refining department, 
process fugitive emission sources (i.e., roofline vents) from smelting 
vessels, slag cleaning vessels, copper converter department and anode 
refining department, each bypass stack, and the entire group of 
fugitive dust sources, as defined in Sec.  63.1459.
    (b) The following affected sources: each copper concentrate dryer, 
each smelting vessel, each slag cleaning vessel, each copper converter 
department, and the entire group of fugitive dust sources at your 
primary copper smelter are existing if you commenced construction or 
reconstruction of the affected source before April 20, 1998.
    (c) The following affected sources: each copper concentrate dryer, 
each smelting vessel, each slag cleaning vessel, each copper converter 
department and the entire group of fugitive dust sources at your 
primary copper smelter are new if you commenced construction or 
reconstruction of the affected source on or after April 20, 1998. An 
affected source is reconstructed if it meets the definition of 
``reconstruction'' in Sec.  63.2.
    (d) The following affected sources: each anode refining department 
and process fugitive emission sources (i.e., roofline vents) from 
smelting vessels, slag cleaning vessels, copper converter department 
and anode refining department are existing if you commenced 
construction or reconstruction of the affected source before January 
11, 2022.
    (e) The following affected sources: each anode refining department 
and process fugitive emission sources (i.e., roofline vents) from 
smelting vessels, slag cleaning vessels, copper converter department 
and anode refining department at your primary copper smelter are new if 
you commenced construction or reconstruction of the affected source on 
or after January 11, 2022. An affected source is reconstructed if it 
meets the definition of ``reconstruction'' in Sec.  63.2.
    (f) The bypass stack is existing if you commenced construction or 
reconstruction of the affected source before July 24, 2023.
    (g) The bypass stack is new if you commenced construction or 
reconstruction of the affected source on or after July 24, 2023. An 
affected source is reconstructed if it meets the definition of 
``reconstruction'' in Sec.  63.2.

[[Page 41693]]

Sec.  63.1443  When do I have to comply with this subpart?

    (a) If you have an existing affected source, you must comply with 
each emission limitation, work practice standard, design standard, and 
operation and maintenance requirement in this subpart that applies to 
you no later than June 13, 2005, except as specified in table 4 to this 
subpart.
    (b) If you have a new affected source and its initial startup date 
is on or before June 12, 2002, you must comply with each emission 
limitation, work practice standard, design standard, and operation and 
maintenance requirement in this subpart that applies to you by June 12, 
2002, except as specified in table 4 to this subpart.
    (c) If you have a new affected source and its initial startup date 
is after June 12, 2002, you must comply with each emission limitation, 
work practice standard, design standard, and operation and maintenance 
requirement in this subpart that applies to you upon initial startup, 
except as specified in in table 4 to this subpart.
    (d) If your primary copper smelter is an area source that becomes a 
major source of HAP (see Sec.  63.1441), the compliance dates listed in 
paragraphs (d)(1) and (2) of this section apply to you.
    (1) Any portion of the existing primary copper smelter that is a 
new affected source or a new reconstructed source must be in compliance 
with this subpart upon startup.
    (2) All other parts of the primary copper smelter must be in 
compliance with this subpart no later than 3 years after it becomes a 
major source (see Sec.  63.1441).
    (e) You must meet the notification and schedule requirements in 
Sec.  63.1454. Several of these notifications must be submitted before 
the compliance date for your affected source.


Sec.  63.1444  What emissions limitations, work practice standards, and 
design standards must I meet for my copper concentrate dryers, smelting 
vessels, slag cleaning vessels, copper converter departments, anode 
refining departments, process fugitive emissions from roofline vents, 
and bypass stacks?

    (a) Copper concentrate dryers. For each copper concentrate dryer, 
you must comply with the emission limitation in paragraph (a)(1) or (2) 
of this section that applies to you.
    (1) For each existing copper concentrate dryer, you must not cause 
to be discharged to the atmosphere from the dryer vent any gases that 
contain filterable particulate matter in excess of 50 milligrams per 
dry standard cubic meter (mg/dscm) as measured using the test methods 
specified in Sec.  63.1450(a).
    (2) For each new copper concentrate dryer, you must not cause to be 
discharged to the atmosphere from the dryer vent any gases that contain 
filterable particulate matter in excess of 23 mg/dscm as measured using 
the test methods specified in Sec.  63.1450(a).
    (b) Smelting vessels. For each smelting vessel, you must comply 
with the emission limitations and work practice standards in paragraphs 
(b)(1) and (2) of this section.
    (1) For each smelting vessel, you must not cause to be discharged 
to the atmosphere any process off-gas that contains nonsulfuric acid 
particulate matter in excess of 6.2 mg/dscm as measured using the test 
methods specified in Sec.  63.1450(b). Process off-gas from a smelting 
vessel is generated when copper ore concentrates and fluxes are being 
smelted to form molten copper matte and slag layers.
    (2) For each smelting vessel, you must control the process fugitive 
emissions released when tapping copper matte or slag from the smelting 
vessel according to paragraphs (b)(2)(i) and (ii) of this section.
    (i) At all times when copper matte or slag is tapped from the 
smelting vessel, you must operate a capture system that collects the 
gases and fumes released from the tapping port in use. The design and 
placement of this capture system must be such that the tapping port 
opening, launder, and receiving vessel (e.g., ladle, slag pot) are 
positioned within the confines or influence of the capture system's 
ventilation draft during those times when the copper matte or slag is 
flowing from the tapping port opening.
    (ii) You must not cause to be discharged to the atmosphere from the 
capture system used to comply with paragraph (b)(2)(i) of this section 
any gases that contain filterable particulate matter in excess of 23 
mg/dscm as measured using the test methods specified in Sec.  
63.1450(a).
    (c) Slag cleaning vessels. For each slag cleaning vessel, you must 
comply with the emission limitations and work practice standards in 
paragraphs (c)(1) through (3) of this section that apply to you.
    (1) For each slag cleaning vessel, except as provided for in 
paragraph (c)(2) of this section, you must not cause to be discharged 
to the atmosphere any process off-gas that contains nonsulfuric acid 
particulate matter in excess of 6.2 mg/dscm as measured using the test 
methods specified in Sec.  63.1450(b).
    (2) As an alternative to complying with the emission limit for 
nonsulfuric acid particulate matter in paragraph (c)(1) of this 
section, for each existing slag cleaning vessel you may choose to 
comply with the emission limit for filterable particulate matter 
specified in this paragraph (c)(2). You must not cause to be discharged 
to the atmosphere any process off-gas that contains filterable 
particulate matter in excess of 46 mg/dscm as measured using the test 
methods specified in Sec.  63.1450(a).
    (3) For each slag cleaning vessel, you must control process 
fugitive emissions released when tapping copper matte or slag from the 
slag cleaning vessel according to paragraphs (c)(3)(i) and (ii) of this 
section.
    (i) At all times when copper matte or slag is tapped from the slag 
cleaning vessel, you must operate a capture system that collects the 
gases and fumes released from the tapping port in use. The design and 
placement of this capture system must be such that the tapping port 
opening, launder, and receiving vessel (e.g., ladle, slag pot) are 
positioned within the confines or influence of the capture system's 
ventilation draft during those times when the copper matte or slag is 
flowing from the tapping port opening.
    (ii) You must not cause to be discharged to the atmosphere from the 
capture system used to comply with paragraph (c)(3)(i) of this section 
any gases that contain filterable particulate matter in excess of 23 
mg/dscm as measured using the test methods specified in Sec.  
63.1450(a).
    (d) Existing copper converter departments. For each existing copper 
converter department, you must comply with the emission limitations and 
work practice standards in paragraphs (d)(1) through (6) of this 
section that apply to you.
    (1) You must operate a capture system that collects the process off 
gas vented from each batch copper converter. At all times when one or 
more batch copper converters are blowing, you must operate the capture 
system according to the written operation and maintenance plan that has 
been prepared according to the requirements in Sec.  63.1447(b).
    (2) If your copper converter department uses Peirce-Smith 
converters, the capture system design must include use of a primary 
hood that covers the entire mouth of the converter vessel when the 
copper converter is positioned for blowing. Additional hoods (e.g., 
secondary hoods) or other capture devices must be included in the 
capture system design as needed to achieve the opacity limit in 
paragraph (d)(4) of this section. The capture system design may use 
multiple intake

[[Page 41694]]

and duct segments through which the ventilation rates are controlled 
independently of each other, and individual duct segments may be 
connected to separate control devices.
    (3) If your copper converter department uses Hoboken converters, 
the capture system must collect all process off-gas vented during 
blowing through the side-flue intake on each converter vessel.
    (4) You must operate the capture system such that any visible 
emissions exiting the roof monitors or roof exhaust fans on the 
building housing the copper converter department meet the opacity limit 
as specified in paragraphs (d)(4)(i) and (ii) of this section.
    (i) The opacity of any visible emissions exiting the roof monitors 
or roof exhaust fans on the building housing the copper converter 
department must not exceed 4 percent as determined by a performance 
test conducted according to Sec.  63.1450(c).
    (ii) The opacity limit in paragraph (d)(4)(i) of this section 
applies only at those times when a performance test is conducted 
according to Sec.  63.1450(c). The requirements for compliance with 
opacity and visible emission standards specified in Sec.  63.6(h) do 
not apply to this opacity limit.
    (5) You must not cause to be discharged to the atmosphere from any 
Peirce-Smith converter primary hood capture system or Hoboken converter 
side-flue intake capture system any process off-gas that contains 
nonsulfuric acid particulate matter in excess of 6.2 mg/dscm as 
measured using the test methods specified in Sec.  63.1450(b).
    (6) You must not cause to be discharged to the atmosphere from any 
secondary capture system any gases that contain filterable particulate 
matter in excess of 23 mg/dscm as measured using the test methods 
specified in Sec.  63.1450(a).
    (e) New copper converter departments. For each new copper converter 
department for which construction commenced on or after April 20, 1998, 
the use of batch copper converters is prohibited. For each new copper 
converter department which will contain a copper converter other than a 
batch converter (such as a continuous converter), you must comply with 
the emission limitation and work practice standards in paragraphs 
(e)(1) and (2) of this section.
    (1) You must not cause to be discharged to the atmosphere from any 
combination of stacks or other vents any captured process off-gas that 
contains filterable particulate matter greater than a daily (24-hour) 
average of 0.031 pounds of particulate matter per ton of copper 
concentrate feed charged to the smelting vessel as measured using the 
test methods specified in Sec.  63.1450(a).
    (2) You must operate a capture system that collects the gases and 
fumes released from converting vessels and conveys the collected gas 
stream to a control device.
    (f) New and existing anode refining departments. Except as provided 
in paragraph (f)(1) of this section, for each new and existing anode 
refining department, you must comply with the emission limitation and 
work practice standards in paragraphs (f)(2) and (3) of this section.
    (1) If the anode refining department process exhaust gases are 
combined with the Hoboken converter process fugitive capture system, 
you must demonstrate compliance with the emission limitation and work 
practice standards in paragraph (g) of this section.
    (2) For each new and existing anode refining department, you must 
not discharge to the atmosphere captured process exhaust gases from the 
anode refining furnaces containing filterable particulate matter 
emissions in excess of 5.8 mg/dscm as measured using the test methods 
specified in Sec.  63.1450(a).
    (3) You must operate a capture system that collects the process 
off-gases and fumes released from the anode refining department and 
convey the collected gas stream to a control device.
    (g) Existing combined anode refining department and Hoboken 
converter process fugitive capture system. For each new and existing 
anode refining department and Hoboken converter process fugitive 
capture system, you must comply with the emission limitation and work 
practice standards in paragraphs (g)(1) through (3) of this section.
    (1) You must not discharge to the atmosphere gases from the 
combination of the anode refining department and Hoboken converter 
process fugitive capture system filterable particulate matter emissions 
in excess of 4.1 mg/dscm as measured using the test methods specified 
in Sec.  63.1450(a).
    (2) You must operate a Hoboken converter process fugitive capture 
system that collects the process off-gases and fumes released from the 
copper converter department.
    (3) You must operate a capture system that collects the process 
off-gases and fumes released from the anode refining department and 
convey the collected gas stream to a control device.
    (h) New and existing sources of process fugitive gases from the 
roofline vents associated with the smelting vessels, the slag cleaning 
vessels, copper converter department, and the anode refining 
department. You must not discharge to the atmosphere process fugitive 
gases from any combination of new and existing roofline vents 
associated with the smelting vessels, slag cleaning vessels, copper 
converter departments and the anode refining departments containing 
filterable particulate matter emissions in excess of 6.3 lb/hr as 
measured using the test methods specified in Sec.  63.1450(e).
    (i) Baghouses. For each baghouse applied to meet any filterable 
particulate matter emission limit in paragraphs (a) through (h) of this 
section, you must operate the baghouse such that the bag leak detection 
system does not alarm for more than 5 percent of the total operating 
time in any semiannual reporting period.
    (j) Venturi wet scrubbers. For each venturi wet scrubber applied to 
meet any filterable particulate matter emission limit in paragraphs (a) 
through (h) of this section, you must comply with the site-specific 
operating limit(s) of maintaining the hourly average pressure drop and 
scrubber water flow rate established during the initial or subsequent 
performance test in accordance with Sec.  63.1450(a)(4).
    (k) Other control devices. For each control device other than a 
baghouse or venturi wet scrubber applied to meet any filterable 
particulate matter emission limit in paragraphs (a) through (h) of this 
section, you must operate the control device as specified in paragraphs 
(k)(1) and (2) of this section.
    (1) You must select one or more operating parameters, as 
appropriate for the control device design, that can be used as 
representative and reliable indicators of the control device operation.
    (2) You must maintain the hourly average value for each of the 
selected parameters at or above the minimum level or at or below the 
maximum level, as appropriate for the selected parameter, established 
during the initial or subsequent performance test in accordance with 
Sec.  63.1450(a)(5).
    (l) Existing source mercury emissions. You must not discharge 
exhaust gases to the atmosphere through any combination of stacks or 
other vents from copper concentrate dryers, copper converter 
department, the anode refining department, slag cleaning vessel and 
smelting vessels containing mercury emissions in excess of 0.033 lb/hr 
for existing sources as measured by the test methods in Sec.  
63.1450(d).
    (m) New source mercury emissions. You must not discharge exhaust 
gases to the atmosphere through any combination of stacks or other 
vents

[[Page 41695]]

from the copper concentrate dryers, copper converter department, the 
anode refining department, slag cleaning vessel and smelting vessels 
containing mercury emissions in excess of 0.00097 lb/hr for new sources 
as measured by the test methods in Sec.  63.1450(d).
    (n) Control devices for mercury. For each control device applied to 
meet the mercury emission limit in paragraph (l) or (m) of this 
section, you must operate the control device as specified in paragraphs 
(n)(1) and (2) of this section.
    (1) You must select one or more operating parameters, as 
appropriate for the control device design, that can be used as 
representative and reliable indicators of the control device operation.
    (2) You must maintain the hourly average value for each of the 
selected parameters at or above the minimum level or at or below the 
maximum level, as appropriate for the selected parameter, established 
during the initial or subsequent performance test in accordance with 
Sec.  63.1450(d)(3).
    (o) New and existing sources of benzene, toluene, chlorine, 
hydrogen chloride, polycyclic aromatic hydrocarbons excluding 
naphthalene, naphthalene, and dioxins/furans emissions. You must not 
discharge exhaust gases to the atmosphere through any combination of 
stacks or other vents from the copper concentrate dryers, copper 
converter department, the anode refining department, slag cleaning 
vessels and the smelting vessels in excess the emission limits in table 
2 to this subpart as measured by the test methods in Sec.  63.1450(f).
    (p) Existing sources of process fugitive gases from the combination 
of roofline vents associated with the Peirce-Smith converter 
department, Inco flash furnace, and anode refining department. For any 
combination of new and existing roofline vents associated with the 
Peirce-Smith converter department, Inco flash furnace, and anode 
refining department, you must comply with the emission limitation and 
design standards in paragraph (p)(1) and (2) of this section.
    (1) Roofline emission limit for the Peirce-Smith converter 
department, Inco flash furnace, and anode refining department. You must 
not discharge to the atmosphere process fugitive gases from any 
combination of existing roofline vents associated with the Peirce-Smith 
copper converter department, Inco flash furnace, and the anode refining 
department containing lead emissions in excess of 0.326 lb/hr as 
measured using the test methods specified in Sec.  63.1450(g).
    (2) Design standards for the Peirce-Smith converter department, 
Inco flash furnace, and anode refining department. You must comply with 
design standards in paragraphs (p)(2)(i) through (iii) of this section 
at all times when the primary copper smelter is operating, except as 
provided herein.
    (i) Flash furnace area capture system. Operate hooding and 
interceptor walls with a design evacuation rate of at least 50,000 cfm 
hourly average to capture fugitive emissions from the flash furnace 
area, matte tapping and slag skimming areas, and route emissions to a 
control device whenever the flash furnace is in operation except for 
brief periods when slag is being returned to the flash furnace using 
the slag return launder.
    (ii) Fuming ladle capture system. Operate hood and interceptor 
walls with a design evacuation rate of at least 40,000 cfm to capture 
fugitive emissions from fuming ladles in the converter aisle and 
material transfer areas, and route emissions to a control device 
whenever a fuming ladle is detected.
    (iii) Anode furnace secondary hood capture and control system. 
Operate a secondary hood around each in-use anode furnace to capture 
process fugitive emissions and route emissions to a control device. The 
design evacuation rate for the total system of all anode furnace 
secondary hoods shall be at least 150,000 cfm hourly average.
    (q) Bypass stack work practice standards. When using the bypass 
stack for planned maintenance of control devices and processes, the 
work practice standard is applicable for the bypass stack for the 
duration of the planned maintenance. You must comply with work practice 
standards in paragraphs (q)(1) through (3) of this section.
    (1) In the case of planned control device or process maintenance, 
feed to the smelting vessel must cease; power to the electric furnace 
must be lowered, and a crust allowed to form on the surface of the 
slag; the operation of the converters must cease and the converters 
rolled out; and the operation of the anode vessels must cease.
    (2) If the fan to the anode refining point source baghouse is 
functioning, then the residual process gases must be redirected to the 
control device. If the process gas from a device being maintenanced can 
be rerouted to a different control device instead of the bypass stack, 
it must be redirected to the control device. Control devices must be 
used until emissions are minimized.
    (3) If there is a shutdown or emergency shutdown event, the control 
devices should continue to run until process emissions cease. If the 
control devices are shut down before the process emissions cease and 
the bypass stack is used to vent the process gas to the atmosphere, 
there will be a violation of the emission and work practice standards.


Sec.  63.1445  What work practice standards must I meet for my fugitive 
dust sources?

    (a) You must control particulate matter emissions from fugitive 
dust sources at your primary copper smelter by operating according to a 
written fugitive dust control plan that has been approved by the 
Administrator or approved authority under 40 CFR part 70 or 71. For the 
purpose of complying with this paragraph (a) you must submit a fugitive 
dust control plan which addresses the fugitive dust sources specified 
in paragraph (b) of this section and includes the information specified 
in paragraph (c) of this section on the schedule provided in paragraphs 
(e) and (f) of this section.
    (b) Before November 12, 2024, your fugitive dust control plan must 
address each of the fugitive dust emission sources listed in paragraphs 
(b)(1) through (6), except paragraphs (b)(1)(i) and (ii), of this 
section that are located at your primary copper smelter. On or after 
November 12, 2024, your fugitive dust control plan must address each of 
the fugitive dust emission sources listed in paragraphs (b)(1) through 
(7) of this section that are located at your primary copper smelter.
    (1) On-site roadways used by trucks or other motor vehicles (e.g., 
front-end loaders) when transporting bulk quantities of fugitive dust 
materials. Paved roads and parking areas that are not used by these 
vehicles do not need to be included in the plan (e.g., employee and 
visitor parking lots).
    (i) You must conduct routine cleaning of paved roads with a 
sweeper, vacuum or wet broom (in accordance with applicable 
recommendations by the manufacturer of the street sweeper, vacuum, or 
wet broom), with such cleaning to occur no less frequently than on a 
daily basis unless the roads have sufficient surface moisture such that 
fugitive dust is not generated.
    (ii) Chemical dust suppressants will be applied not less frequently 
than once per month at slag haul roads and not less frequently than 
every 6 weeks on all other unpaved roads unless the roads have 
sufficient surface moisture such that fugitive dust is not generated.
    (2) Unloading of fugitive dust materials from trucks or railcars.
    (3) Outdoor piles used for storage of fugitive dust materials.

[[Page 41696]]

    (4) Bedding areas used for blending copper concentrate and other 
feed constituents.
    (5) Each transfer point in conveying systems used to transport 
fugitive dust materials. These points include, but are not limited to, 
transfer of material from one conveyor belt to another and transfer of 
material to a hopper or bin.
    (6) Other site-specific sources of fugitive dust emissions that the 
Administrator or delegated authority under 40 CFR part 70 or 71 
designate to be included in your fugitive dust control plan.
    (7) The cargo compartment of all trucks or other motor vehicles 
(e.g., front-end loaders) when transporting bulk quantities of fugitive 
dust materials must be maintained to ensure:
    (i) The floor, sides, and/or tailgate(s) are free of holes or other 
openings.
    (ii) All loads of trucks containing copper concentrate arriving at 
the facility are covered with a tarp to prevent spills and fugitive 
emissions.
    (iii) Trucks are loaded only to such a level as to prevent spillage 
over the side.
    (iv) A speed limit of 15 mph is required.
    (v) All dust producing material internally transferred or moved by 
truck at the facility is covered with a tarp to prevent spills and 
fugitive emissions.
    (c) Your fugitive dust control plan must describe the control 
measures you use to control fugitive dust emissions from each source 
addressed in the plan, as applicable and appropriate for your site 
conditions. Examples of control measures include, but are not limited 
to, locating the source inside a building or other enclosure, 
installing and operating a local hood capture system over the source 
and venting the captured gas stream to a control device, placing 
material stockpiles below grade, installing wind screens or wind fences 
around the source, spraying water on the source as weather conditions 
require, applying appropriate dust suppression agents on the source, or 
combinations of these control measures.
    (d) The requirement for you to operate according to a written 
fugitive dust control plan must be incorporated in your operating 
permit that is issued by the approved authority under 40 CFR part 70 or 
71. A copy of your fugitive dust control plan must be sent to the 
approved authority under 40 CFR part 70 or 71 on or before the 
compliance date for your primary copper smelter, as specified in Sec.  
63.1443 or paragraph (b) of this section.
    (e) For any element of the fugitive dust control plan that requires 
new construction at the facility, the owner or operator shall complete 
such construction, in accordance with the specifications and schedule 
set forth in the approved fugitive dust control plan.
    (f) The fugitive dust control plan must be reviewed, updated (if 
necessary), and then submitted to the approved permitting authority 
under 40 CFR part 70 or 71 with each application for the title V 
operating permit renewal and with each permit application for the 
construction or modification of lead-bearing fugitive dust generating 
sources. On or after November 12, 2024, the owner or operator must 
submit a copy fugitive dust plan in PDF format to the EPA via 
Compliance and Emissions Data Reporting Interface (CEDRI), which can be 
accessed through EPA's Central Data Exchange (CDX) (https://cdx.epa.gov) following the procedure specified in Sec. Sec.  63.1455(e) 
and 63.9(k).


Sec.  63.1446  What alternative emission limitation may I meet for my 
combined gas streams?

    (a) For situations where you combine gas streams from two or more 
affected sources for discharge to the atmosphere through a single vent, 
you may choose to meet the requirements in paragraph (b) of this 
section as an alternative to complying with the individual filterable 
particulate matter emission limits specified in Sec.  63.1444 that 
apply to you. This alternative emission limit for a combined gas stream 
may be used for any combination of the affected source gas steams 
specified in paragraphs (a)(1) through (6) of this section.
    (1) Gas stream discharged from a copper concentrate dryer vent that 
would otherwise be subject to Sec.  63.1444(a)(1) or (2);
    (2) Gas stream discharged from a smelting vessel capture system 
that would otherwise be subject to Sec.  63.1444(b)(2)(ii);
    (3) Process off-gas stream discharged from a slag cleaning vessel 
that would otherwise be subject to Sec.  63.1444(c)(2);
    (4) Gas stream discharged from a slag cleaning vessel capture 
system that would otherwise be subject to Sec.  63.1444(c)(3)(ii);
    (5) Gas stream discharged from an existing batch copper converter 
secondary capture system that would otherwise be subject to Sec.  
63.1444(d)(6); and
    (6) Gas stream discharged from anode refining departments that 
would otherwise be subject to Sec.  63.1444(f)(2).
    (b) You must meet the requirements specified in paragraphs (b)(1) 
and (2) of this section for the combined gas stream discharged through 
a single vent.
    (1) For each combined gas stream discharged through a single vent, 
you must not cause to be discharged to the atmosphere any gases that 
contain filterable particulate matter in excess of the emission limit 
calculated using the procedure in paragraph (b)(2) of this section and 
measured using the test methods specified in Sec.  63.1450(a).
    (2) You must calculate the alternative filterable particulate 
matter emission limit for your combined gas stream using equation 1 to 
this paragraph (b)(2). The volumetric flow rate value for each of the 
individual affected source gas streams that you use for equation 1 
(i.e., the flow rate of the gas stream discharged from the affected 
source but before this gas stream is combined with the other gas 
streams) is to be the average of the volumetric flow rates measured 
using the test method specified in Sec.  63.1450(a)(1)(ii):

Equation 1 to Paragraph (b)(2)
[GRAPHIC] [TIFF OMITTED] TR13MY24.109


Where:
EAlt = Alternative filterable particulate matter emission 
limit for the combined gas stream discharged to atmosphere through a 
single vent (mg/dscm);
Ed = Filterable particulate matter emission limit 
applicable to copper concentrate dryer as specified in Sec.  
63.1444(a)(1) or (2) (mg/dscm);
Qd = Copper concentrate dryer exhaust gas stream 
volumetric flow rate before being combined with other gas streams 
(dscm/hr);
Esv = Filterable particulate matter emission limit for smelting 
vessel capture system as specified in Sec.  63.1444(b)(2)(ii) (mg/
dscm);
Qsv = Smelting vessel capture system exhaust gas stream volumetric 
flow rate before being combined with other gas streams (dscm/hr);
Escvp = Filterable particulate matter emission limit for slag 
cleaning vessel process off-gas as specified in Sec.  63.1444(c)(2) 
(mg/dscm);

[[Page 41697]]

Qscvp = Slag cleaning vessel process off-gas volumetric flow rate 
before being combined with other gas streams (dscm/hr);
Escvf = Filterable particulate matter emission limit for slag 
cleaning vessel capture system as specified in Sec.  
63.1444(c)(3)(ii) (mg/dscm);
Qscvf = Slag cleaning vessel capture system exhaust gas stream 
volumetric flow rate before being combined with other gas streams 
(dscm/hr);
Ecc = Filterable particulate emission limit for the existing batch 
copper converter secondary capture system as specified in Sec.  
63.1444(d)(6) (mg/dscm);
Qcc = Batch copper converter capture system exhaust gas stream 
volumetric flow rate before being combined with other gas streams 
(dscm/hr);
Eard = Filterable particulate matter emission limit for 
the anode refining department as specified in Sec.  63.1444(f)(2); 
and
Qard = Anode refining department exhaust gas stream 
volumetric flow rate before being combined with other gas streams 
(dscm/hr).

    (c) For each baghouse applied to meet any filterable particulate 
matter emission limit in paragraph (b) of this section, you must 
operate the baghouse such that the bag leak detection system does not 
alarm for more than 5 percent of the total operating time in any 
semiannual reporting period.
    (d) For each venturi wet scrubber applied to meet any filterable 
particulate matter emission limit in paragraph (b) of this section, you 
must maintain the hourly average pressure drop and scrubber water flow 
rate at or above the minimum levels established during the initial or 
subsequent performance test in accordance with Sec.  63.1450(a)(4).
    (e) For each control device other than a baghouse or venturi wet 
scrubber applied to meet any filterable particulate matter emission 
limit in paragraph (b) of this section, you must operate the control 
device as specified in paragraphs (e)(1) and (2) of this section.
    (1) You must select one or more operating parameters, as 
appropriate for the control device design, that can be used as 
representative and reliable indicators of the control device operation.
    (2) You must maintain the hourly average value for each of the 
selected parameters at or above the minimum level or at or below the 
maximum level, as appropriate for the selected parameter, established 
during the initial or subsequent performance test in accordance with 
Sec.  63.1450(a)(5).


Sec.  63.1447  What are my operation and maintenance requirements?

    (a) Before November 12, 2024, as required by Sec.  63.6(e)(1)(i), 
you must always operate and maintain your affected source, including 
air pollution control and monitoring equipment, in a manner consistent 
with good air pollution control practices for minimizing emissions at 
least to the levels required by this subpart. On or after November 12, 
2024, at all times, you must maintain and operate any affected source, 
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 a 
source is operating in compliance with operation and maintenance 
requirements 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 source.
    (b) You must prepare and operate at all times according to a 
written operation and maintenance plan for each capture system and 
control device subject to standards in Sec.  63.1444 or Sec.  63.1446. 
The plan must address the requirements in paragraphs (b)(1) through (4) 
of this section as applicable to the capture system or control device.
    (1) Preventative maintenance. You must perform preventative 
maintenance for each capture system and control device according to 
written procedures specified in your operation and maintenance plan. 
The procedures must include a preventative maintenance schedule that is 
consistent with the manufacturer's instructions for routine and long-
term maintenance.
    (2) Capture system inspections. You must conduct monthly 
inspections of the equipment components of the capture system that can 
affect the performance of the system to collect the gases and fumes 
emitted from the affected source (e.g., hoods, exposed ductwork, 
dampers, fans) according to written procedures specified in your 
operation and maintenance plan. The inspection procedure must include 
the requirements in paragraphs (b)(2)(i) through (iii) of this section 
as applicable to the capture system or control device.
    (i) Observations of the physical appearance of the equipment to 
confirm the physical integrity of the equipment (e.g., verify by visual 
inspection no holes in ductwork or hoods, no flow constrictions caused 
by dents, or accumulated dust in ductwork).
    (ii) Inspection, and if necessary testing, of equipment components 
to confirm that the component is operating as intended (e.g., verify by 
appropriate measures that flow or pressure sensors, damper plates, 
automated damper switches and motors are operating according to 
manufacture or engineering design specifications).
    (iii) In the event that a defective or damaged component is 
detected during an inspection, you must initiate corrective action 
according to written procedures specified in your operation and 
maintenance plan to correct the defect or deficiency as soon as 
practicable.
    (3) Copper converter department capture system operating limits. 
You must establish, according to the requirements in paragraph 
(b)(3)(i) through (iii) of this section, operating limits for the 
capture system that are representative and reliable indicators of the 
performance of capture system when it is used to collect the process 
off-gas vented from batch copper converters during blowing.
    (i) Select operating limit parameters appropriate for the capture 
system design that are representative and reliable indicators of the 
performance of the capture system when it is used to collect the 
process off-gas vented from batch copper converters during blowing. At 
a minimum, you must use appropriate operating limit parameters that 
indicate the level of the ventilation draft and the damper position 
settings for the capture system when operating to collect the process 
off-gas from the batch copper converters during blowing. Appropriate 
operating limit parameters for ventilation draft include, but are not 
limited to, volumetric flow rate through each separately ducted hood, 
total volumetric flow rate at the inlet to control device to which the 
capture system is vented, fan motor amperage, or static pressure. Any 
parameter for damper position setting may be used that indicates the 
duct damper position relative to the fully open setting.
    (ii) For each operating limit parameter selected in paragraph 
(b)(3)(i) of this section, designate the value or setting for the 
parameter at which the capture system operates during batch copper 
converter blowing. If your blister copper production operations allow 
for more than one batch copper converter to be operating simultaneously 
in the blowing mode, designate the value or setting for the parameter 
at which the capture system operates during each possible batch copper 
converter blowing configuration that you may operate at

[[Page 41698]]

your smelter (i.e., the operating limits with one converter blowing, 
with two converters blowing, with three converters blowing, as 
applicable to your smelter).
    (iii) Include documentation in the plan to support your selection 
of the operating limits established for the capture system. This 
documentation must include a description of the capture system design, 
a description of the capture system operation during blister copper 
production, a description of each selected operating limit parameter, a 
rationale for why you chose the parameter, a description of the method 
used to monitor the parameter according to the requirements in Sec.  
63.1452(a), and the data used to set the value or setting for the 
parameter for each of your batch copper converter configurations.
    (4) Baghouse leak detection corrective actions. In the event a bag 
leak detection system alarm is triggered, you must initiate corrective 
action according to written procedures specified in your operation and 
maintenance plan to determine the cause of the alarm within 1 hour of 
the alarm, initiate corrective action to correct the cause of the 
problem within 24 hours of the alarm, and complete the corrective 
action as soon as practicable. Corrective actions may include, but are 
not limited to, the activities listed in paragraphs (b)(3)(i) through 
(vi) of this section.
    (i) Inspecting the baghouse for air leaks, torn or broken bags or 
filter media, or any other condition that may cause an increase in 
emissions.
    (ii) Sealing off defective bags or filter media.
    (iii) Replacing defective bags or filter media or otherwise 
repairing the control device.
    (iv) Sealing off a defective baghouse compartment.
    (v) Cleaning the bag leak detection system probe, or otherwise 
repair the bag leak detection system.
    (vi) Shutting down the process producing the particulate emissions.


Sec.  63.1448  What are my general requirements for complying with this 
subpart?

    (a) Before November 12, 2024, you must be in compliance with the 
emission limitations, work practice standards, and operation and 
maintenance requirements in this subpart at all times, except during 
periods of startup, shutdown, and malfunction as defined in Sec.  63.2. 
On or after November 12, 2024, you must be in compliance with the 
emission limitations, work practice standards, design standards, and 
operation and maintenance requirements in this subpart at all times.
    (b) During the period between the compliance date specified for 
your affected source in Sec.  63.1443, and the date upon which 
continuous monitoring systems have been installed and certified and any 
applicable operating limits have been set, you must maintain a log 
detailing the operation and maintenance of the process and emissions 
control equipment.
    (c) Before November 12, 2024, you must develop a written startup, 
shutdown, and malfunction plan according to the provisions in Sec.  
63.6(e)(3). For affected sources, a startup, shutdown, and malfunction 
plan is not required on or after November 12, 2024.


Sec.  63.1449  By what dates must I conduct performance tests or other 
initial compliance demonstrations?

    (a) As required in Sec.  63.7(a)(2), you must conduct a performance 
test within 180 calendar days of the compliance date that is specified 
in Sec.  63.1443 for your affected source to demonstrate initial 
compliance with each emission and opacity limit in Sec. Sec.  63.1444 
and 63.1446 that applies to you.
    (b) For each work practice standard and operation and maintenance 
requirement that applies to you where initial compliance is not 
demonstrated using a performance test or opacity observation, you must 
demonstrate initial compliance within 30 calendar days after the 
compliance date that is specified for your affected source in Sec.  
63.1443.


Sec.  63.1450  What test methods and other procedures must I use to 
demonstrate initial compliance with the emission limitations and design 
standards?

    (a) Filterable particulate matter emission limits. Before November 
12, 2024, you must conduct each performance test to determine 
compliance with the filterable particulate matter emission limits in 
Sec.  63.1444 or Sec.  63.1446 that apply to you according to the 
requirements for representative test conditions specified in Sec.  
63.7(e)(1) and using the test methods and procedures in paragraphs 
(a)(1) through (5) of this section. On or after November 12, 2024, you 
must conduct each performance test to determine compliance with the 
filterable particulate matter emission limits in Sec.  63.1444 or Sec.  
63.1446 that apply to you according to the requirements for 
representative test conditions specified in paragraph (a)(6) of this 
section and using the test methods and procedures in paragraphs (a)(1) 
through (5) of this section.
    (1) Determine the concentration of filterable particulate matter 
according to the test methods in appendices A-1 through A-8 to 40 CFR 
part 60 as specified in paragraphs (a)(1)(i) through (v) of this 
section.
    (i) Method 1 to select sampling port locations and the number of 
traverse points. Sampling ports must be located at the outlet of the 
control device and prior to any releases to the atmosphere.
    (ii) Method 2, 2F, or 2G to determine the volumetric flow rate of 
the stack gas.
    (iii) Method 3, 3A, or 3B to determine the dry molecular weight of 
the stack gas. The ANSI/ASME PTC 19-10-1981 Part 10 (incorporated by 
reference, see Sec.  63.14) is an acceptable alternative to EPA Method 
3B manual portion only but not the instrumental portion.
    (iv) Method 4 to determine the moisture content of the stack gas.
    (v) Method 5, 5D, or 17, as applicable, to determine the 
concentration of filterable particulate matter.
    (2) As an alternative to using the applicable method specified in 
paragraph (a)(1)(v) of this section, you may determine filterable 
particulate matter emissions from the control device using Method 29 in 
appendix A-8 to 40 CFR part 60 provided that you follow the procedures 
and precautions prescribed in Method 29. If the control device is a 
positive pressure baghouse, you must also follow the measurement 
procedure specified in sections 8.1 through 8.3 of Method 5D in 
appendix A-3 to 40 CFR part 60.
    (3) You must conduct three separate test runs for each performance 
test. Each test run must have a minimum sampling time of 60 minutes and 
a minimum sampling volume of 0.85 dscm. For the purpose of determining 
compliance with the applicable filterable particulate matter emission 
limit, the arithmetic mean of the results for the three separate test 
runs is used.
    (4) For a venturi wet scrubber applied to emissions from an 
affected source and subject to emission limits and work practice 
standards in Sec.  63.1444(j) or Sec.  63.1446(d) for pressure drop and 
scrubber water flow rate, you must establish site-specific operating 
limits according to the procedures in paragraphs (a)(4)(i) and (ii) of 
this section.
    (i) Using the continuous parameter monitoring system (CPMS) 
required in Sec.  63.1452, measure and record the pressure drop and 
scrubber water flow rate during each run of the particulate matter 
performance test.
    (ii) Compute and record the hourly average pressure drop and 
scrubber water flow rate for each individual test run. Your operating 
limits are the lowest

[[Page 41699]]

average pressure drop and scrubber water flow rate value in any of the 
three runs that meet the applicable emission limit.
    (5) For a control device other than a baghouse or venturi wet 
scrubber applied to emissions from an affected source and subject to 
work practice standards and emission limit(s) in Sec.  63.1444(k) or 
Sec.  63.1446(e) for appropriate, site-specific operating parameters 
that are representative and reliable indicators of the control device 
performance, you must establish a site-specific operating limit(s) 
according to the procedures in paragraphs (a)(5)(i) through (iv) of 
this section.
    (i) Select one or more operating parameters, as appropriate for the 
control device design, that can be used as representative and reliable 
indicators of the control device operation.
    (ii) Using the CPMS required in Sec.  63.1452, measure and record 
the selected operating parameters for the control device during each 
run of the filterable particulate matter performance test.
    (iii) Compute and record the hourly average value for each of the 
selected operating parameters for each individual test run. Your 
operating limits are the lowest value or the highest value, as 
appropriate for the selected operating parameter, measured in any of 
the three runs that meet the applicable emission limit.
    (iv) You must prepare written documentation to support your 
selection of the operating parameters used for the control device. This 
documentation must include a description of each selected parameter, a 
rationale for why you chose the parameter, a description of the method 
used to monitor the parameter, and the data recorded during the 
performance test and used to set the operating limit(s).
    (6) You must conduct each performance test that applies to your 
affected source under normal operating conditions of the affected 
source. The owner or operator may not conduct performance tests during 
periods of malfunction. The use of the bypass stack during a 
performance test of the process shall invalidate the performance test. 
The owner or operator 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 shall make available to the 
Administrator such records as may be necessary to determine the 
conditions of performance tests.
    (b) Nonsulfuric acid particulate matter emission limits. Before 
November 12, 2024, you must conduct each performance test to determine 
compliance with the nonsulfuric acid particulate matter emission limits 
in Sec.  63.1444 that apply to you according to the requirements for 
representative test conditions specified in Sec.  63.7(e)(1) and using 
the test methods and procedures in paragraphs (b)(1) and (2) of this 
section. On or after November 12, 2024, you must conduct each 
performance test to determine compliance with the nonsulfuric acid 
particulate matter emission limits in Sec.  63.1444 that apply to you 
according to the requirements for representative test conditions 
specified in paragraph (b)(4) of this section and using the test 
methods and procedures in paragraphs (b)(1) through (3) of this 
section.
    (1) Determine the concentration of nonsulfuric acid particulate 
matter according to the test methods in appendices A-1 through A-8 to 
40 CFR part 60 as specified in paragraphs (b)(1)(i) through (v) of this 
section.
    (i) Method 1 to select sampling port locations and the number of 
traverse points. Sampling ports must be located at the outlet of the 
control device and prior to any releases to the atmosphere.
    (ii) Method 2, 2F, or 2G to determine the volumetric flow rate of 
the stack gas.
    (iii) Method 3, 3A, or 3B to determine the dry molecular weight of 
the stack gas. The ANSI/ASME PTC 19-10-1981 Part 10 (incorporated by 
reference, see Sec.  63.14) is an acceptable alternative to EPA Method 
3B manual portion only but not the instrumental portion.
    (iv) Method 4 to determine the moisture content of the stack gas.
    (v) Method 5B to determine the nonsulfuric acid particulate matter 
emissions.
    (2) You must conduct three separate test runs for each performance 
test. Each test run must have a minimum sampling time of 240 minutes 
and a minimum sampling volume of 3.4 dscm. For the purpose of 
determining compliance with the nonsulfuric acid particulate matter 
emission limit, the arithmetic mean of the results for the three 
separate test runs is used.
    (3) For a control device applied to emissions from an affected 
source and subject to work practice standards and emission limit(s) in 
Sec.  63.1444(i), (j), or (k) or Sec.  63.1446(e) for appropriate, 
site-specific operating parameters that are representative and reliable 
indicators of the control device performance, you must establish a 
site-specific operating limit(s) according to the procedures in 
paragraphs (a)(5)(i) through (iv) of this section.
    (4) You must conduct each performance test that applies to your 
affected source under normal operating conditions of the affected 
source. The owner or operator may not conduct performance tests during 
periods of malfunction. The use of the bypass stack during a 
performance test of the process shall invalidate the performance test. 
The owner or operator 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 shall make available to the 
Administrator such records as may be necessary to determine the 
conditions of performance tests.
    (c) Copper converter department capture system opacity limit. You 
must conduct each performance test to determine compliance with the 
opacity limit in Sec.  63.1444 using the test methods and procedures in 
paragraphs (c)(1) through (9) of this section and during the 
particulate matter performance test.
    (1) You must conduct the performance test during the period when 
the primary copper smelter is operating under conditions representative 
of the smelter's normal blister copper production rate. You may not 
conduct a performance test during a malfunction. Before conducting the 
performance test, you must prepare a written test plan specifying the 
copper production conditions to be maintained throughout the opacity 
observation period and including a copy of the written documentation 
you have prepared according to paragraph (a)(3) of this section to 
support the established operating limits for the copper converter 
department capture system. You must submit a copy of the test plan for 
review and approval by the Administrator or delegated authority. During 
the observation period, you must collect appropriate process 
information and copper converter department capture system operating 
information to prepare documentation sufficient to verify that all 
opacity observations were made during the copper production and capture 
system operating conditions specified in the approved test plan.
    (2) You must notify the Administrator or delegated authority before 
conducting the opacity observations to allow the Administrator or 
delegated authority the opportunity to have authorized

[[Page 41700]]

representatives attend the test. Written notification of the location 
and scheduled date for conducting the opacity observations must be 
received by the Administrator on or before 30 calendar days before this 
scheduled date.
    (3) You must gather the data needed for determining compliance with 
the opacity limit using qualified visible emission observers and 
process monitors as described in paragraphs (c)(3)(i) and (ii) of this 
section.
    (i) Opacity observations must be performed by a sufficient number 
of qualified visible emission observers to obtain two complete 
concurrent sets of opacity readings for the required observation 
period. Each visible emission observer must be certified as a qualified 
observer by the procedure specified in section 3 of Method 9 in 
appendix A-4 to 40 CFR part 60. The entire set of readings during the 
required observation period does not need to be made by the same two 
observers. More than two observers may be used to allow for 
substitutions and provide for observer rest breaks. The owner or 
operator must obtain proof of current visible emission reading 
certification for each observer. ASTM D7520-16 (incorporated by 
reference, see Sec.  63.14) is an acceptable alternative to EPA Method 
9 with the specified conditions in paragraphs (c)(3)(i)(A) through (E) 
of this section.
    (A) During the digital camera opacity technique (DCOT) 
certification procedure outlined in section 9.2 of ASTM D7520-16, you 
or the DCOT vendor must present the plumes in front of various 
backgrounds of color and contrast representing conditions anticipated 
during field use such as blue sky, trees, and mixed backgrounds (clouds 
and/or a sparse tree stand).
    (B) You must also have standard operating procedures in place 
including daily or other frequency quality checks to ensure the 
equipment is within manufacturing specifications as outlined in section 
8.1 of ASTM D7520-16.
    (C) You must follow the record keeping procedures outlined in Sec.  
63.10(b)(1) for the DCOT certification, compliance report, data sheets, 
and all raw unaltered JPEGs used for opacity and certification 
determination.
    (D) You or the DCOT vendor must have a minimum of four (4) 
independent technology users apply the software to determine the 
visible opacity of the 300 certification plumes. For each set of 25 
plumes, the user may not exceed 15% opacity of anyone reading and the 
average error must not exceed 7.5% opacity.
    (E) This approval does not provide or imply a certification or 
validation of any vendor's hardware or software. The onus to maintain 
and verify the certification and/or training of the DCOT camera, 
software and operator in accordance with ASTM D7520-16 and this letter 
is on the facility, DCOT operator, and DCOT vendor.
    (ii) A person (or persons) familiar with the copper production 
operations conducted at the smelter must serve as the indoor process 
monitor. The indoor process monitor is stationed at a location inside 
the building housing the batch copper converters such that he or she 
can visually observe and record operations that occur in the batch 
copper converter aisle during the times that the visible emission 
observers are making opacity readings. More than one indoor process 
monitor may be used to allow for substitutions and provide for rest 
breaks.
    (4) You must make all opacity observations using Method 9 in 
appendix A-4 to 40 CFR part 60 and following the procedures described 
in paragraphs (c)(4)(i) and (ii) of this section. ASTM D7520-16 
(incorporated by reference, see Sec.  63.14) is an acceptable 
alternative to EPA Method 9 with the specified conditions in paragraphs 
(c)(3)(i)(A) through (E) of this section.
    (i) Each visible emission observer must make his or her readings at 
a position from the outside of the building that houses the copper 
converter department such that the observer's line-of-sight is 
approximately perpendicular to the longer axis of the converter 
building, and the observer has an unobstructed view of the building 
roof monitor sections or roof exhaust fan outlets that are positioned 
over each of the batch copper converters inside the building. Opacity 
readings can only be made during those times when the observer's 
position meets the sun orientation and other conditions specified in 
section 2.1 of Method 9 in appendix A-4 to 40 CFR part 60.
    (ii) At 15-second intervals, each visible emission observer views 
the building roof monitor sections or roof exhaust fan outlets that are 
positioned over each of the batch copper converters inside the building 
and reads the opacity of the visible plumes. If no plume is visible, 
the observer records zero as the opacity value for the 15-second 
interval. In situations when it is possible for an observer to 
distinguish two or more visible emission plumes from the building roof 
monitor sections or roof exhaust fan outlets, the observer must 
identify, to the extent feasible, the plume having the highest opacity 
and record his or her opacity reading for that plume as the opacity 
value for the 15-second interval.
    (5) You must make opacity observations for a period of sufficient 
duration to obtain a minimum of 120 1-minute intervals during which at 
least one copper converter is blowing and no interferences have 
occurred from other copper production events, as specified in paragraph 
(c)(7) of this section, which generate visible emissions inside the 
building that potentially can interfere with the visible emissions from 
the converter capture systems as seen by the outside observers. To 
obtain the required number of 1-minute intervals, the observation 
period may be divided into two or more segments performed on the same 
day or on different days if conditions prevent the required number of 
opacity readings from being obtained during one continuous time period. 
Examples of these conditions include, but are not limited to, changes 
in the sun's orientation relative to visible emission observers' 
positions such that the conditions in Method 9 in appendix A-4 to 40 
CFR part 60 are no longer met or an unexpected thunderstorm. If the 
total observation period is divided into two or more segments, all 
opacity observations must be made during the same set of copper 
production conditions described in your approved test plan as required 
by paragraph (c)(1) of this section.
    (6) You must gather indoor process information during all times 
that the visible emission observers are making opacity readings outside 
the building housing the copper converter department. The indoor 
process monitor must continually observe the operations occurring in 
the copper converter department and prepare a written record of his or 
her observations using the procedure specified in paragraphs (c)(6)(i) 
through (iv) of this section.
    (i) At the beginning of each observation period or segment, the 
clock time setting on the watch or clock to be used by the indoor 
process monitor must be synchronized with the clock time settings for 
the timepieces to be used by the outdoor opacity observers.
    (ii) During each period or segment when opacity readings are being 
made by the visible emission observers, the indoor process monitor must 
continuously observe the operations occurring in the copper converter 
department and record his or her observations in a log book, on data 
sheets, or other type of permanent written format.
    (iii) When a batch copper converter is blowing, a record must be 
prepared for the converter that includes, but is not

[[Page 41701]]

limited to, the clock times for when blowing begins and when blowing 
ends and the converter blowing rate. This information may be recorded 
by the indoor process monitor or by a separate, automated computer data 
system.
    (iv) The process monitor must record each event other than 
converter blowing that occurs in or nearby the converter aisle that he 
or she observes to generate visible emissions inside the building. The 
recorded entry for each event must include, but is not limited to, a 
description of the event and the clock times when the event begins and 
when the event ends.
    (7) You must prepare a summary of the data for the entire 
observation period using the information recorded during the 
observation period by the outdoor visible emission observers and the 
indoor process monitor and the procedure specified in paragraphs 
(c)(7)(i) through (iv) of this section.
    (i) Using the field data sheets, identify the 1-minute clock times 
for which a total of eight opacity readings were made and recorded by 
both observers at 15-second intervals according to the test procedures 
(i.e., a total of four opacity values have been recorded for the 1-
minute interval by each of the two observers). Calculate the average of 
the eight 15-second interval readings recorded on the field data sheets 
by the two observers during the clock time minute interval (add the 
four consecutive 15-second interval opacity readings made by Observer A 
during the specified clock time minute, plus the four consecutive 15-
second interval opacity readings made by Observer B during the same 
clock time minute, and divide the resulting total by eight). Record the 
clock time and the opacity average for the 1-minute interval on a data 
summary sheet. Figure 1 to this subpart shows an example of the format 
for the data summary sheet you may use, but are not required to use.
    (ii) Using the data summary sheets prepared according to paragraph 
(c)(7)(i) of this section and the process information recorded 
according to paragraph (c)(6)(iii) of this section, identify those 1-
minute intervals for which at least one of the batch copper converters 
was blowing.
    (iii) Using the data summary sheets prepared according to paragraph 
(c)(7)(ii) of this section and the process information recorded 
according to paragraph (c)(6)(iv) of this section, identify the 1-
minute intervals during which at least one copper converter was blowing 
but none of the interference events listed in paragraphs (c)(7)(iii)(A) 
through (F) of this section occurred. Other ancillary activities not 
listed but conducted in or adjacent to the converter aisle during the 
opacity observations are not considered to be interference events 
(e.g., converter aisle cleaning, placement of smoking ladles or skulls 
on the converter aisle floor).
    (A) Charging of copper matte, reverts, or other materials to a 
batch copper converter;
    (B) Skimming slag or other molten materials from a batch copper 
converter;
    (C) Pouring of blister copper or other molten materials from a 
batch copper converter;
    (D) Return of slag or other molten materials to the flash smelting 
vessel or slag cleaning vessel;
    (E) Roll-out or roll-in of the batch copper converter; or
    (F) Smoke and fumes generated inside the converter building by 
operation of the smelting vessel, the slag cleaning vessel (if used), 
anode refining and casting processes that drift into the copper 
converter department.
    (iv) Using the data summary sheets prepared according to paragraph 
(c)(7)(iii) of this section, up to five 1-minute intervals following an 
interference event may be eliminated from data used for the compliance 
determination calculation specified in paragraph (c)(8) of this section 
by applying a time delay factor. The time delay factor must be a 
constant number of minutes not to exceed 5 minutes that is added to the 
clock time recorded when cessation of the interference event occurs. 
The same time delay factor must be used for all interference events 
(i.e., a constant time delay factor for the smelter of 1 minute, 2 
minutes, 3 minutes, 4 minutes, or 5 minutes). The number of minutes to 
be used for the time delay factor is determined based on the site-
specific equipment and converter building configuration. An explanation 
of the rationale for selecting the value used for the time delay factor 
must be prepared and included in the test report.
    (8) You must use the data summary prepared in paragraph (c)(7) of 
this section to calculate the average opacity value for a minimum of 
120 1-minute intervals during which at least one copper converter was 
blowing with no interference events as determined according to 
paragraphs (c)(7)(iii) and (iv) of this section. Average opacity is 
calculated using equation 1 to this paragraph (c)(8):
Equation 1 to paragraph (c)(8)
[GRAPHIC] [TIFF OMITTED] TR13MY24.110


Where:
VEave = Average opacity to be used for compliance determination 
(percent);
n = Total number of 1-minute intervals during which at least one 
copper converter was blowing with no interference events as 
determined according to paragraphs (c)(7)(iii) and (iv) of this 
section (at least 120 1-minute intervals);
i = 1-minute interval ``i'' during which at least one copper 
converter was blowing with no interference events as determined 
according to paragraphs (c)(7)(iii) and (iv) of this section; and
VEi = Average opacity value calculated for the eight 
opacity readings recorded during 1-minute interval ``i'' (percent).

    (9) You must certify that the copper converter department capture 
system operated during the performance test at the operating limits 
established in your capture system operation and maintenance plan using 
the procedure specified in paragraphs (c)(9)(i) through (iv) of this 
section.
    (i) Concurrent with all opacity observations, measure and record 
values for each of the operating limit parameters in your capture 
system operation and maintenance plan according to the monitoring 
requirements specified in Sec.  63.1452(a).
    (ii) For any dampers that are manually set and remain in the same 
position at all times the capture system is operating, the damper 
position must be visually checked and recorded at the beginning and end 
of each opacity observation period segment.
    (iii) Review the recorded monitoring data. Identify and explain any 
times during batch copper converter blowing when the capture system 
operated outside the applicable operating limits.
    (iv) Certify in your performance test report that during all 
observation period segments, the copper converter department capture 
system was

[[Page 41702]]

operating at the values or settings established in your capture system 
operation and maintenance plan.
    (d) Mercury emissions. You must conduct each performance test to 
determine compliance with the mercury emission limits in Sec.  63.1444 
that apply to you according to the requirements for representative test 
conditions specified in paragraph (d)(4) of this section and using the 
test methods and procedures in paragraphs (d)(1) through (3) of this 
section.
    (1) Determine the concentration of mercury according to the test 
methods in appendices A-1 through A-8 to 40 CFR part 60 as specified in 
paragraphs (d)(1)(i) through (v) of this section.
    (i) Method 1 to select sampling port locations and the number of 
traverse points. Sampling ports must be located at the outlet of the 
control device and prior to any releases to the atmosphere.
    (ii) Method 2, 2F, or 2G to determine the volumetric flow rate of 
the stack gas.
    (iii) Method 3, 3A, or 3B to determine the dry molecular weight of 
the stack gas. The ANSI/ASME PTC 19-10-1981 Part 10 (incorporated by 
reference, see Sec.  63.14) is an acceptable alternative to EPA Method 
3B manual portion only but not the instrumental portion.
    (iv) Method 4 to determine the moisture content of the stack gas.
    (v) Method 29, 30A, or 30B, as applicable, to determine the 
concentration of mercury. You can also use ASTM D6784-16 (incorporated 
by reference, see Sec.  63.14) or equivalent.
    (2) You must conduct three separate test runs for each performance 
test. Duration of sampling is at least two hours per run. If performing 
measurements using Method 29 in appendix A-8 to 40 CFR part 60, you 
must collect a minimum sample volume of 1.7 dscm (60 dscf). For the 
purpose of determining compliance with the applicable mercury emission 
limit, the arithmetic mean of the results for the three separate test 
runs is used.
    (3) For a control device or process operating parameter applied to 
emissions from an affected source and subject to site-specific 
operating limit(s) in Sec.  63.1444(n) for appropriate, site-specific 
operating parameters that are representative and reliable indicators of 
the control device performance, you must establish a site-specific 
operating limit(s) according to the procedures in paragraphs (d)(3)(i) 
through (iv) of this section.
    (i) Select one or more operating parameters, as appropriate for the 
control device design or process parameter (i.e., mercury content of 
concentrate feed), that can be used as representative and reliable 
indicators of the control device or process operation.
    (ii) Using the CPMS required in Sec.  63.1452, measure and record 
the selected operating parameters for the control device during each 
run of the mercury performance test.
    (iii) Compute and record the hourly average value for each of the 
selected operating parameters for each individual test run. Your 
operating limits are the lowest value or the highest value, as 
appropriate for the selected operating parameter, measured in any of 
the three runs that meet the applicable emission limit.
    (iv) You must prepare written documentation to support your 
selection of the operating parameters used for the control device. This 
documentation must include a description of each selected parameter, a 
rationale for why you chose the parameter, a description of the method 
used to monitor the parameter, and the data recorded during the 
performance test and used to set the operating limit(s).
    (4) You must conduct each performance test that applies to your 
affected source under normal operating conditions of the affected 
source. The owner or operator may not conduct performance tests during 
periods of malfunction. The use of the bypass stack during a 
performance test of the process shall invalidate the performance test. 
The owner or operator 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 shall make available to the 
Administrator such records as may be necessary to determine the 
conditions of performance tests.
    (e) Anode refining department, copper converter department, slag 
cleaning vessels, and smelting vessels process fugitive roofline vent 
filterable particulate matter emission limit. You must conduct each 
performance test to determine compliance with the roofline vent process 
fugitive filterable particulate matter emission limits in Sec.  63.1444 
that apply to you according to the requirements for representative test 
conditions specified in paragraph (e)(3) of this section and using the 
test methods and procedures in paragraphs (e)(1) and (2) of this 
section.
    (1) Determine the concentration of anode refining department, 
copper converter department, slag cleaning vessels, and smelting 
vessels process fugitive roofline vent filterable particulate matter 
according to the test methods in appendices A-1 through A-8 to 40 CFR 
part 60 as specified in paragraphs (e)(1)(i) through (vi) of this 
section.
    (i) Method 1 to select sampling port locations and the number of 
traverse points. Sampling ports must be located at the outlet of the 
control device and prior to any releases to the atmosphere. Use Method 
5D, section 8.1.3, Roof Monitor or Monovent, or approved sample 
locations by EPA Office of Air and Radiation (OAR), OAQPS, Measurement 
Technology Group or delegated authority.
    (ii) Method 2, 2F, or 2G to determine the volumetric flow rate of 
the stack gas or calibrated anemometer.
    (iii) Method 3, 3A, or 3B to determine the dry molecular weight of 
the stack gas.
    The ANSI/ASME PTC 19-10-1981 Part 10 (incorporated by reference, 
see Sec.  63.14) is an acceptable alternative to EPA Method 3B manual 
portion only but not the instrumental portion.
    (iv) Method 4 to determine the moisture content of the stack gas.
    (v) Method 17 to determine in-stack mass volume of the anode 
refining, converter and smelting process fugitive roof vent filterable 
particulate matter emissions. Isokinetic calculations are waived due to 
low flow rates and high variability. Use the filter specified in 
section 7.2.1 of Method 29. An approved Federal reference method (FRM)/
Federal equivalent method (FEM) may be used if it can tolerate the 150 
[deg]F temperatures on the roof vents. Tapered element oscillating 
microbalances (TEOMs) are not appropriate for this sampling. An 
alternative test method may be requested to EPA OAR, OAQPS, Measurement 
Technology Group.
    (vi) Method 9 to establish opacity as an operating parameter, if 
appropriate. ASTM D7520-16 (incorporated by reference, see Sec.  63.14) 
is an acceptable alternative to EPA Method 9 with the specified 
conditions in paragraphs (c)(3)(i)(A) through (E) of this section.
    (2) You must conduct three separate test runs for each performance 
test. Each test run must have a minimum sampling time of 12 hours. For 
the purpose of determining compliance with the filterable particulate 
matter emission limit, the arithmetic mean of the results for the three 
separate test runs for each roofline vent (i.e., anode refining 
department, copper converter department, smelting vessels, slag 
cleaning vessels) is used. The three test run average of the filterable 
particulate

[[Page 41703]]

matter emission rates from each vent should be summed to compare to the 
emission limit in Sec.  63.1444.
    (3) You must conduct each performance test that applies to your 
affected source under normal operating conditions of the affected 
source. The owner or operator may not conduct performance tests during 
periods of malfunction. The use of the bypass stack during a 
performance test of the process shall invalidate the performance test. 
The owner or operator 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 shall make available to the 
Administrator such records as may be necessary to determine the 
conditions of performance tests.
    (f) Benzene, toluene, chlorine, hydrogen chloride, polycyclic 
aromatic hydrocarbons excluding naphthalene, naphthalene, and dioxins/
furans emissions. You must conduct each performance test to determine 
compliance with the benzene, toluene, chlorine, hydrogen chloride, 
polycyclic aromatic hydrocarbons excluding naphthalene, naphthalene, 
and dioxins/furans emission limits in table 2 to this subpart that 
apply to you according to the requirements for representative test 
conditions specified in paragraph (f)(8) of this section and using the 
test methods and procedures in paragraphs (f)(1) through (7) of this 
section.
    (1) Use the test methods in appendices A-1 through A-8 to 40 CFR 
part 60 as specified in paragraphs (f)(1)(i) through (iv) of this 
section to select sampling port locations and the number of traverse 
points and to determine the volumetric flow rate, dry molecular weight, 
and moisture content of the stack gas.
    (i) Method 1 to select sampling port locations and the number of 
traverse points. Sampling ports must be located at the outlet of the 
control device and prior to any releases to the atmosphere.
    (ii) Method 2, 2F, or 2G to determine the volumetric flow rate of 
the stack gas.
    (iii) Method 3, 3A, or 3B to determine the dry molecular weight of 
the stack gas. The ANSI/ASME PTC 19-10-1981 Part 10 (incorporated by 
reference, see Sec.  63.14) is an acceptable alternative to EPA Method 
3B manual portion only but not the instrumental portion.
    (iv) Method 4 to determine the moisture content of the stack gas.
    (2) Determine the concentration of benzene and toluene for each 
stack using Method 18 in to appendix A-6 to 40 CFR part 60 to determine 
the concentration of benzene and toluene; or as an alternative ASTM 
D6420-99 (Reapproved 2010) (incorporated by reference, see Sec.  
63.14), may be used provided that the target compound(s) are those 
listed in section 1.1 of ASTM D6420-99 (Reapproved 2010) as measurable; 
the target compounds do not include methane and ethane because their 
atomic mass is less than 35; and the test results are not a total VOC 
method. Each test must consist of three separate runs. The duration of 
sampling must be at least two hours per run.
    (3) Determine the concentration of chlorine and hydrogen chloride 
for each stack using Method 26A in appendix A-8 to 40 CFR part 60. Each 
test must consist of three separate runs. The minimum sample volume 
must be at least 2 dry cubic meters per run. Each run must be conducted 
for a minimum of 1 hour.
    (4) Determine the concentration of polycyclic aromatic hydrocarbons 
excluding naphthalene, naphthalene, and dioxins/furans for each stack 
using Method 23 in appendix A-7 to 40 CFR part 60. Each test must 
consist of three separate runs. The test duration must be at least 3 
hours and the must be at least 3 dscm (106 dscf). Method 23 complete 
list of PAHs and dioxin and furan congeners must be analyzed and 
reported.
    (5) During each stack test run, measure the weight of copper 
concentrate feed charged to the smelting vessel and calculate the 
emissions rate in pounds of pollutant per ton of copper concentrate 
feed charged to the smelting vessel (lb/ton), except for dioxins/furans 
which should be calculated in nanograms of pollutant Toxicity 
Equivalent Quotient (TEQ) per megagram of copper concentrate feed 
charged to the smelting vessel (ng/Mg) for each test run. To calculate 
the TEQ, multiply each D/F congener emission concentration times the 
appropriate Toxicity Equivalent Factor (TEF) in table 3 to this 
subpart. If any measurement result is reported as below the method 
detection limit, use the method detection limit for that value when 
calculating the emission rate. Calculate the total emissions rate for 
each test run by summing the emissions across all stacks, as shown in 
equation 2 to this paragraph (f)(5).
Equation 2 to Paragraph (f)(5)
[GRAPHIC] [TIFF OMITTED] TR13MY24.111

Where:

Ef,i = Emissions rate for test run ``i'' for all emission 
stacks at the facility ``f'', lb/ton or ng/Mg, as applicable of 
copper concentrate feed charged to the smelting vessel;
Cs = Emission rate for stack ``s'' measured during test 
run ``i'' on at facility ``f'', lb/dscf;
Qs = Average volumetric flow rate of stack gas measured 
at stack ``s'' during test run ``i'' at facility ``f'', dscf/hour;
P = Copper concentrate feed charged to the smelting vessel during 
the stack test, ton/hour or Mg/hour, as applicable; and
n = Number of emissions stacks at facility ``f''.

    (6) Calculate the average emissions rate for each facility using 
the three test runs, as shown in equation 3 to this paragraph (f)(6). 
For the purposes of determining compliance with the applicable emission 
limits in table 2 to this subpart, the arithmetic mean of the results 
for the three separate test runs is used as calculated using equation 
3.
Equation 3 to paragraph (f)(6)
[GRAPHIC] [TIFF OMITTED] TR13MY24.112



[[Page 41704]]


Where:

Ef = Average emission rate for facility ``f'', lb/ton or 
ng/Mg of copper concentrate feed charged to the smelting vessel, as 
applicable.
E1 = Emissions rate for run 1 for facility ``f'', lb/ton 
or ng/Mg of copper concentrate feed charged to the smelting vessel, 
as applicable.
E2 = Emissions rate for run 2 for facility ``f'', lb/ton 
or ng/Mg of copper concentrate feed charged to the smelting vessel, 
as applicable.
E3 = Emissions rate for run 3 for facility ``f'', lb/ton 
or ng/Mg of copper concentrate feed charged to the smelting vessel, 
as applicable.
* * * * *
    (7) For a control device applied to emissions from an affected 
source and subject to work practice standards and emission limit(s) in 
Sec.  63.1444(o) for appropriate, site-specific operating parameters 
that are representative and reliable indicators of the control device 
performance, you must establish a site-specific operating limit(s) 
according to the procedures in paragraphs (f)(7)(i) through (iv) of 
this section.
    (i) Select one or more operating parameters, as appropriate for the 
control device design, that can be used as representative and reliable 
indicators of the control device operation.
    (ii) Using the CPMS required in Sec.  63.1452, measure and record 
the selected operating parameters for the control device during each 
run of the benzene, toluene, chlorine, hydrogen chloride, polycyclic 
aromatic hydrocarbons excluding naphthalene, naphthalene and dioxins/
furans performance test.
    (iii) Compute and record the hourly average value for each of the 
selected operating parameters for each individual test run. Your 
operating limits are the lowest value or the highest value, as 
appropriate for the selected operating parameter, measured in any of 
the three runs that meet the applicable emission limit.
    (iv) You must prepare written documentation to support your 
selection of the operating parameters used for the control device. This 
documentation must include a description of each selected parameter, a 
rationale for why you chose the parameter, a description of the method 
used to monitor the parameter, and the data recorded during the 
performance test and used to set the operating limit(s).
    (8) You must conduct each performance test that applies to your 
affected source under normal operating conditions of the affected 
source. You may not conduct a performance test during a malfunction. 
The use of the bypass stack during a performance test of the process 
shall invalidate the performance test. The owner or operator 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 shall make available to the Administrator such records as may 
be necessary to determine the conditions of performance tests.
    (g) Peirce-Smith converter department, Inco flash furnace, and 
anode refining department process fugitive roofline vent lead. For 
facilities using a combination of Peirce-Smith converter department, 
Inco flash furnace, and anode refining department, you must conduct 
each performance test to determine compliance with the roofline vent 
process fugitive lead emission limits in Sec.  63.1444(p)(1) that apply 
to you according to the requirements for representative test conditions 
specified in paragraph (g)(3) of this section and using the test 
methods and procedures in paragraphs (g)(1) and (2) of this section. 
You must also comply with establishing operating parameters in 
paragraphs (g)(4) through (7) of this section.
    (1) Determine the concentration of Peirce-Smith converter 
department, Inco flash furnace, and anode refining department process 
fugitive roofline vent lead according to the test methods in appendices 
A-1 through A-8 to 40 CFR part 60 as specified in paragraphs (g)(1)(i) 
through (vii) of this section.
    (i) Method 1 to select sampling port locations and the number of 
traverse points. Sampling ports must be located at the outlet of the 
control device and prior to any releases to the atmosphere. Use Method 
5D section 8.1.3 Roof Monitor or Monovent or approved sample locations 
by MTG or delegated authority.
    (ii) Method 2, 2F, or 2G to determine the volumetric flow rate of 
the stack gas or calibrated anemometer.
    (iii) Method 3, 3A, or 3B to determine the dry molecular weight of 
the stack gas. The ANSI/ASME PTC 19-10-1981 Part 10 (incorporated by 
reference, see Sec.  63.14) is an acceptable alternative to EPA Method 
3B manual portion only but not the instrumental portion.
    (iv) Method 4 to determine the moisture content of the stack gas.
    (v) Method 17 to determine in-stack mass volume of the anode 
refining, converter and smelting process fugitive roof vent lead 
emissions. Isokinetic calculations are waived due to low flow rates and 
high variability. Use the filter specified in section 7.2.1 of Method 
29. An approved FRM/FEM may be used if it can tolerate the 150 F 
temperatures on the roof vents. TEOMs are not appropriate for this 
sampling. An alternative test method may be requested to EPA OAR, 
OAQPS, Measurement Technology Group.
    (vi) Method 29 filter analysis by inductively coupled plasma mass 
spectrometry (ICP-MS) for lead.
    (vii) Method 9 to establish opacity as an operating parameter, if 
appropriate. ASTM D7520-16 (incorporated by reference, see Sec.  63.14) 
is an acceptable alternative to EPA Method 9 with the specified 
conditions in paragraphs (c)(3)(i)(A) through (E) of this section.
    (2) You must conduct three separate test runs for each performance 
test. Each test run must have a minimum sampling time of 12 hours. For 
the purpose of determining compliance with the lead emission limit, the 
arithmetic mean of the results for the three separate test runs for 
each roofline vent (i.e., anode refining department, copper converter 
department, smelting vessels, slag cleaning vessels) is used. The three 
test run average of the lead emission rates from each vent should be 
summed to compare to the emission limit in Sec.  63.1444.
    (3) You must conduct each performance test that applies to your 
affected source under normal operating conditions of the affected 
source. The owner or operator may not conduct performance tests during 
periods of malfunction. The use of the bypass stack during a 
performance test of the process shall invalidate the performance test. 
The owner or operator 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 shall make available to the 
Administrator such records as may be necessary to determine the 
conditions of performance tests.
    (4) Establish a site-specific operating limit for a parameter, like 
opacity, based on values measured during the performance test.
    (5) For your flash furnace capture system you must establish site 
specific operating parameters as specified in Sec.  63.1444(p)(2)(i).
    (6) For your fuming ladle capture system, you must establish site 
specific

[[Page 41705]]

operating parameters as specified in Sec.  63.1444(p)(2)(ii).
    (7) For your anode furnace secondary capture and control system, 
you must establish site specific operating parameters as specified in 
Sec.  63.1444(p)(2)(iii).


Sec.  63.1451  How do I demonstrate initial compliance with the 
emission limitations, work practice standards, design standards, and 
operation and maintenance requirements that apply to me?

    (a) Filterable particulate matter emission limits. For each copper 
concentrate dryer, smelting vessel, slag cleaning vessel, copper 
converter department, anode refining department, and combination of 
anode refining department and Hoboken converter process fugitive 
capture system subject to a filterable particulate matter emission 
limit in Sec.  63.1444 or Sec.  63.1446, you have demonstrated initial 
compliance if you meet both of the conditions in paragraphs (a)(1) and 
(2) of this section.
    (1) The average concentration of filterable particulate matter from 
the affected source, any capture system, or control device applied to 
emissions from the affected source, measured according to the 
performance test procedures in Sec.  63.1450(a), did not exceed the 
applicable emission limit, and establishes operating parameter.
    (2) You have submitted a notification of compliance status 
according to the requirements in Sec.  63.1454(e) and performance test 
results according to the requirements in Sec.  63.1455(e).
    (b) Nonsulfuric acid particulate matter emissions limits. For each 
smelting vessel, slag cleaning vessel, and copper converter departments 
subject to the nonsulfuric acid particulate matter emissions limit in 
Sec.  63.1444 as applies to you, you have demonstrated initial 
compliance if you meet both of the conditions in paragraphs (b)(1) and 
(2) of this section.
    (1) The average concentration of nonsulfuric acid particulate 
matter in the process off-gas discharged from the affected source, 
measured according to the performance test procedures in Sec.  
63.1450(b), did not exceed 6.2 mg/dscm.
    (2) You have submitted a notification of compliance status 
according to the requirements in Sec.  63.1454(e) and performance test 
results according to the requirements in Sec.  63.1455(e).
    (c) Copper converter department visible emissions. For each 
existing copper converter department subject to the opacity limit in 
Sec.  63.1444, you have demonstrated initial compliance if you meet 
both of the conditions in paragraphs (c)(1) and (2) of this section.
    (1) The opacity of visible emissions exiting the roof monitors or 
roof exhaust fans on the building housing the copper converter 
department measured according to the performance test procedures in 
Sec.  63.1450(c), did not exceed 4 percent opacity.
    (2) You have submitted a notification of compliance status 
according to the requirements in Sec.  63.1454(e).
    (d) Copper converter department capture systems. You have 
demonstrated initial compliance of the copper converter department 
capture system if you meet all of the conditions in paragraphs (d)(1) 
through (4) of this section.
    (1) Prepared the capture system operation and maintenance plan 
according to the requirements in Sec.  63.1447(b);
    (2) Conducted an initial performance test according to the 
procedures of Sec.  63.1450(c) demonstrating the opacity of any visible 
emissions exiting the roof monitors or roof exhaust fans on the 
building housing the copper converter department does not exceed 4 
percent opacity;
    (3) Included in your notification of compliance status a copy of 
your written capture system operation and maintenance plan and have 
certified in your notification of compliance status that you will 
operate the copper converter department capture system at all times 
during blowing at the values or settings established for the operating 
limits in that plan; and
    (4) Submitted a notification of compliance status according to the 
requirements in Sec.  63.1454(e) and performance test results according 
to the requirements in Sec.  63.1455(e).
    (e) Baghouses. For each baghouse subject to operating limits in 
Sec.  63.1444(i) or Sec.  63.1446(c), you have demonstrated initial 
compliance if you meet all of the conditions in paragraphs (e)(1) 
through (3) of this section.
    (1) You have included in your written operation and maintenance 
plan required under Sec.  63.1447(b) detailed descriptions of the 
procedures you use for inspection, maintenance, bag leak detection, and 
corrective action for the baghouse.
    (2) You have certified in your notification of compliance status 
that you will operate the baghouse according to your written operation 
and maintenance plan.
    (3) You have submitted the notification of compliance status 
according to the requirements in Sec.  63.1454(e).
    (f) Venturi wet scrubbers. For each venturi wet scrubber subject to 
operating limits in Sec.  63.1444(j) or Sec.  63.1446(d), you have 
demonstrated initial compliance if you meet all of the conditions in 
paragraphs (f)(1) through (3) of this section.
    (1) Established site-specific operating limits for pressure drop 
and scrubber water flow rate and have a record of the pressure drop and 
scrubber water flow rate measured during the performance test you 
conduct to demonstrate initial compliance with paragraph (a) or (k) of 
this section.
    (2) Certified in your notification of compliance status that you 
will operate the venturi wet scrubber within the established operating 
limits for pressure drop and scrubber water flow rate.
    (3) Submitted a notification of compliance status according to the 
requirements in Sec.  63.1454(e).
    (g) Other control devices. For each control device other than a 
baghouse or venturi wet scrubber subject to operating limits in Sec.  
63.1444(k) or (n) or Sec.  63.1446(e), you have demonstrated initial 
compliance if you meet all of the conditions in paragraphs (g)(1) 
through (4) of this section.
    (1) Selected one or more operating parameters, as appropriate for 
the control device design, that can be used as representative and 
reliable indicators of the control device operation.
    (2) Established site-specific operating limits for each of the 
selected operating parameters based on values measured during the 
performance test you conduct to demonstrate initial compliance with 
paragraph (a) of this section and have prepared written documentation 
according to the requirements in Sec.  63.1450(a)(5)(iv).
    (3) Included in your notification of compliance status a copy of 
the written documentation you have prepared to demonstrate compliance 
with paragraph (g)(2) of this section and have certified in your 
notification of compliance status that you will operate the control 
device within the established operating limits.
    (4) Submitted a notification of compliance status according to the 
requirements in Sec.  63.1454(e).
    (h) Fugitive dust sources. For all fugitive dust sources subject to 
work practice standards in Sec.  63.1445, you have demonstrated initial 
compliance if you meet all of the conditions in paragraphs (h)(1) 
through (3) of this section.
    (1) Prepared a written fugitive dust control plan according to the 
requirements in Sec.  63.1445 and it has been approved by the delegated 
authority.
    (2) Certified in your notification of compliance status that you 
will control emissions from the fugitive dust sources

[[Page 41706]]

according to the procedures in the approved plan.
    (3) Submitted the notification of compliance status according to 
the requirements in Sec.  63.1454(e).
    (i) Operation and maintenance requirements. You have demonstrated 
initial compliance with the operation and maintenance requirements that 
apply to you if you meet all of the conditions in paragraphs (i)(1) 
through (3) of this section.
    (1) Prepared an operation and maintenance plan according to the 
requirements in Sec.  63.1447(b).
    (2) Certified in your notification of compliance status that you 
will operate each capture system and control device according to the 
procedures in the plan.
    (3) Submitted the notification of compliance status according to 
the requirements in Sec.  63.1454(e).
    (j) Mercury emissions. For any combination of copper concentrate 
dryers, smelting vessel, copper converter department, slag cleaning 
vessel and anode refining department subject to a mercury emission 
limit in Sec.  63.1444, you have demonstrated initial compliance if you 
meet the conditions in paragraphs (j)(1) through (3) of this section.
    (1) The sum of the mercury emissions (lb/hr) from the affected 
sources measured according to the performance test procedures in Sec.  
63.1450(d), did not exceed the applicable emission limit.
    (2) Established a site-specific operating limit for a parameter 
based on values measured during the performance test you conduct to 
demonstrate initial compliance with this paragraph (j) and have 
prepared written documentation according to the requirements in Sec.  
63.1450(d)(3)(iv).
    (3) You have submitted a notification of compliance status 
according to the requirements in Sec.  63.1454(e) and performance test 
results according to the requirements in Sec.  63.1455(e).
    (k) Process fugitive filterable particulate matter from roofline 
vents. For emissions from roofline vents associated with the smelting 
vessels, slag cleaning vessels, copper converter department, and anode 
refining department subject to a filterable particulate matter emission 
limit in Sec.  63.1444(h), you have demonstrated initial compliance if 
you meet the conditions in paragraphs (k)(1) through (3) of this 
section.
    (1) The sum of filterable particulate matter emissions from the 
combination of roofline vents as measured according to the performance 
test procedures in Sec.  63.1450(e), did not exceed 6.3 lb/hr.
    (2) Established a site-specific operating limit for a parameter, 
like opacity, based on values measured during the performance test you 
conduct to demonstrate initial compliance with this paragraph (k) and 
have prepared written documentation according to the requirements in 
Sec.  63.1450(e).
    (3) You have submitted a notification of compliance status 
according to the requirements in Sec.  63.1454(e) and performance test 
results according to the requirements in Sec.  63.1455(e).
    (l) Benzene, toluene, chlorine, hydrogen chloride, polycyclic 
aromatic hydrocarbons excluding naphthalene, naphthalene, and dioxins/
furans emissions. For any combination of copper concentrate dryer, 
smelting vessel, slag cleaning vessel, copper converter department, and 
anode refining department subject to the benzene, toluene, chlorine, 
hydrogen chloride, polycyclic aromatic hydrocarbons excluding 
naphthalene, naphthalene, and dioxins/furans emission limits in table 2 
to this subpart, you have demonstrated initial compliance if you meet 
both of the conditions in paragraphs (l)(1) and (2) to this section.
    (1) The emissions of benzene, toluene, chlorine, hydrogen chloride, 
polycyclic aromatic hydrocarbons excluding naphthalene, naphthalene, 
and dioxins/furans emissions per mass of copper concentrate feed to the 
smelting vessel from the affected sources measured according to the 
performance test procedures in Sec.  63.1450(f), did not exceed the 
applicable emission limit.
    (2) You have submitted a notification of compliance status 
according to the requirements in Sec.  63.1454(e) and performance test 
results according to the requirements in Sec.  63.1455(e).
    (m) Process fugitive lead from roofline vents. For emissions from 
the combination of roofline vents associated with the Peirce-Smith 
converter department, Inco flash furnace, and anode refining department 
subject to a lead emission limit and design standards in Sec.  
63.1444(p), you have demonstrated initial compliance if you meet the 
conditions in paragraphs (m)(1) through (5) of this section.
    (1) The sum of lead emissions from the combination of roofline 
vents as measured according to the performance test procedures in Sec.  
63.1450(g), did not exceed 0.326 lb/hr.
    (2) You have submitted a notification of compliance status and 
performance test results according to requirements of Sec. Sec.  
63.1454(e), 63.1455(e)(1), and 63.9(k)
    (3) For your flash furnace capture system, you have established 
timed interlock on the slag return launder.
    (4) For your fuming ladle capture system, you have determined flow 
rate by a calibrated flowmeter or test.
    (5) For your anode furnace secondary hood capture and control 
system, you have determined flow rate by a calibrated flowmeter or 
test.


Sec.  63.1452  What are my monitoring requirements?

    (a) Copper converter department capture systems. For each operating 
limit established under your capture system operation and maintenance 
plan, you must install, operate, and maintain an appropriate monitoring 
device according to the requirements in paragraphs (a)(1) through (6) 
of this section to measure and record the operating limit value or 
setting at all times the copper converter department capture system is 
operating during batch copper converter blowing. Dampers that are 
manually set and remain in the same position at all times the capture 
system is operating are exempted from the requirements of this 
paragraph (a).
    (1) Install the monitoring device, associated sensor(s), and 
recording equipment according to the manufacturers' specifications. 
Locate the sensor(s) used for monitoring in or as close to a position 
that provides a representative measurement of the parameter being 
monitored.
    (2) If a flow measurement device is used to monitor the operating 
limit parameter, you must meet the requirements in paragraphs (a)(2)(i) 
through (iv) of this section.
    (i) Locate the flow sensor and other necessary equipment such as 
straightening vanes in a position that provides a representative flow.
    (ii) Use a flow sensor with a minimum tolerance of 2 percent of the 
flow rate.
    (iii) Reduce swirling flow or abnormal velocity distributions due 
to upstream and downstream disturbances.
    (iv) Conduct a flow sensor calibration check at least semiannually.
    (3) If a pressure measurement device is used to monitor the 
operating limit parameter, you must meet the requirements in paragraphs 
(a)(3)(i) through (v) of this section.
    (i) Locate the pressure sensor(s) in or as close to a position that 
provides a representative measurement of the pressure.
    (ii) Minimize or eliminate pulsating pressure, vibration, and 
internal and external corrosion.
    (iii) Use a gauge with a minimum tolerance of 0.5 inch of water or 
a transducer with a minimum tolerance of 1 percent of the pressure 
range.
    (iv) Check pressure tap pluggage daily.

[[Page 41707]]

    (v) Using a manometer, check gauge calibration quarterly and 
transducer calibration monthly.
    (4) Conduct calibration and validation checks any time the sensor 
exceeds the manufacturer's specifications or you install a new sensor.
    (5) At least monthly, inspect all components for integrity, all 
electrical connections for continuity, and all mechanical connections 
for leakage.
    (6) Record the results of each inspection, calibration, and 
validation check.
    (b) Baghouses. For each baghouse subject to the operating limit in 
Sec.  63.1444(i) or Sec.  63.1446(c) for the bag leak detection system 
alarm, you must at all times monitor the relative change in particulate 
matter loadings using a bag leak detection system according to the 
requirements in paragraph (b)(1) of this section and conduct regular 
inspections according to the requirements in paragraph (b)(2) of this 
section.
    (1) You must install, operate, and maintain each bag leak detection 
system according to the requirements in paragraphs (b)(1)(i) through 
(vii) of this section.
    (i) The system must be certified by the manufacturer to be capable 
of detecting emissions of particulate matter at concentrations of 10 
milligrams per actual cubic meter (0.0044 grains per actual cubic foot) 
or less.
    (ii) The system must provide output of relative changes in 
particulate matter loadings.
    (iii) The system must be equipped with an alarm that will sound 
when an increase in relative particulate loadings is detected over a 
preset level. The alarm must be located such that it can be heard by 
the appropriate plant personnel.
    (iv) Each system that works based on the triboelectric effect must 
be installed, operated, and maintained in a manner consistent with the 
guidance document ``Fabric Filter Bag Leak Detection Guidance,'' EPA-
454/R-98-015, September 1997. You may obtain a copy of this guidance 
document by contacting the National Technical Information Service 
(NTIS) at 800-553-6847. You may install, operate, and maintain other 
types of bag leak detection systems in a manner consistent with the 
manufacturer's written specifications and recommendations.
    (v) To make the initial adjustment of the system, establish the 
baseline output by adjusting the sensitivity (range) and the averaging 
period of the device. Then, establish the alarm set points and the 
alarm delay time.
    (vi) Following the initial adjustment, do not adjust the 
sensitivity or range, averaging period, alarm set points, or alarm 
delay time, except as detailed in your operation and maintenance plan. 
Do not increase the sensitivity by more than 100 percent or decrease 
the sensitivity by more than 50 percent over a 365-day period unless a 
responsible official certifies, in writing, that the baghouse has been 
inspected and found to be in good operating condition.
    (vii) Where multiple detectors are required, the system's 
instrumentation and alarm may be shared among detectors.
    (2) You must conduct baghouse inspections at their specified 
frequencies according to the requirements in paragraphs (b)(2)(i) 
through (viii) of this section.
    (i) Monitor the pressure drop across each baghouse cell each day to 
ensure pressure drop is within the normal operating range identified in 
the manual.
    (ii) Confirm that dust is being removed from hoppers through weekly 
visual inspections or other means of ensuring the proper functioning of 
removal mechanisms.
    (iii) Check the compressed air supply for pulse-jet baghouses each 
day.
    (iv) Monitor cleaning cycles to ensure proper operation using an 
appropriate methodology.
    (v) Check bag cleaning mechanisms for proper functioning through 
monthly visual inspection or equivalent means.
    (vi) Make monthly visual checks of bag tension on reverse air and 
shaker-type baghouses to ensure that bags are not kinked (kneed or 
bent) or laying on their sides. You do not have to make this check for 
shaker-type baghouses using self-tensioning (spring-loaded) devices.
    (vii) Confirm the physical integrity of the baghouse through 
quarterly visual inspections of the baghouse interior for air leaks.
    (viii) Inspect fans for wear, material buildup, and corrosion 
through quarterly visual inspections, vibration detectors, or 
equivalent means.
    (c) Venturi wet scrubbers. For each venturi wet scrubber subject to 
the operating limits for pressure drop and scrubber water flow rate in 
Sec.  63.1444(j) or Sec.  63.1446(d), you must at all times monitor the 
hourly average pressure drop and water flow rate using a CPMS. You must 
install, operate, and maintain each CPMS according to the requirements 
in paragraphs (c)(1) and (2) of this section.
    (1) For the pressure drop CPMS, you must meet the requirements in 
paragraphs (c)(1)(i) through (vi) of this section.
    (i) Locate the pressure sensor(s) in or as close to a position that 
provides a representative measurement of the pressure and that 
minimizes or eliminates pulsating pressure, vibration, and internal and 
external corrosion.
    (ii) Use a gauge with a minimum measurement sensitivity of 0.5 inch 
of water or a transducer with a minimum measurement sensitivity of 1 
percent of the pressure range.
    (iii) Check the pressure tap for pluggage daily.
    (iv) Using a manometer, check gauge calibration quarterly and 
transducer calibration monthly.
    (v) Conduct calibration checks any time the sensor exceeds the 
manufacturer's specified maximum operating pressure range, or install a 
new pressure sensor.
    (vi) At least monthly, inspect all components for integrity, all 
electrical connections for continuity, and all mechanical connections 
for leakage.
    (2) For the scrubber water flow rate CPMS, you must meet the 
requirements in paragraphs (c)(2)(i) through (iv) of this section.
    (i) Locate the flow sensor and other necessary equipment in a 
position that provides a representative flow and that reduces swirling 
flow or abnormal velocity distributions due to upstream and downstream 
disturbances.
    (ii) Use a flow sensor with a minimum measurement sensitivity of 2 
percent of the flow rate.
    (iii) Conduct a flow sensor calibration check at least semiannually 
according to the manufacturer's instructions.
    (iv) At least monthly, inspect all components for integrity, all 
electrical connections for continuity, and all mechanical connections 
for leakage.
    (d) Other control devices and operating parameters. For each 
control device other than a baghouse or venturi wet scrubber subject to 
the operating limits for appropriate parameters in Sec.  63.1444(k) or 
Sec.  63.1446(e), or a control device for mercury subject to Sec.  
63.1444(n), you must at all times monitor each of your selected 
parameters using an appropriate CPMS. You must install, operate, and 
maintain each CPMS according to the equipment manufacturer's 
specifications and the requirements in paragraphs (d)(1) though (5) of 
this section.
    (1) Locate the sensor(s) used for monitoring in or as close to a 
position that provides a representative measurement of the parameter 
being monitored.
    (2) Determine the hourly average of all recorded readings.

[[Page 41708]]

    (3) Conduct calibration and validation checks any time the sensor 
exceeds the manufacturer's specifications or you install a new sensor.
    (4) At least monthly, inspect all components for integrity, all 
electrical connections for continuity, and all mechanical connections 
for leakage.
    (5) Record the results of each inspection, calibration, and 
validation check.
    (e) Continuous monitoring. Except for monitoring malfunctions, 
associated repairs, and required quality assurance or control 
activities (including as applicable, calibration checks and required 
zero and span adjustments), you must monitor continuously (or collect 
data at all required intervals) at all times an affected source is 
operating.
    (f) Data collection for assessing compliance. You may not use data 
recorded during monitoring malfunctions, associated repairs, and 
required quality assurance or control activities in data averages and 
calculations used to report emission or operating levels or to fulfill 
a minimum data availability requirement, if applicable. You must use 
all the data collected during all other periods in assessing 
compliance.
    (g) Monitoring malfunctions. A monitoring malfunction is any 
sudden, infrequent, not reasonably preventable failure of the monitor 
to provide valid data. Monitoring failures that are caused in part by 
poor maintenance or careless operation are not malfunctions.
    (h) Bypass stacks. You must maintain an appropriate monitoring 
device according to the requirements in paragraph (h)(1) or (2) of this 
section to demonstrate the work practice standards are limiting the 
emissions at all times the bypass stack is in use.
    (1) If a SO2 continuous emissions monitoring system 
(CEMS) is utilized as a continuous monitor during planned maintenance 
events, a cylinder gas audit (CGA) and daily calibration or a 3-point 
linearity test must be conducted prior to the performance test 
according to Procedure 1, section 5.1.2, in appendix F to 40 CFR part 
60 to conduct the CGA.
    (2) If a particulate matter (PM) detector is CPMS, you must 
install, operate, and maintain each PM detector according to the 
equipment manufacturer's specifications and the requirements in 
paragraphs (h)(2)(i) through (v) of this section.
    (i) Locate the detector(s) used for monitoring in or as close to a 
position that provides a representative measurement of the parameter 
being monitored.
    (ii) Determine the hourly average of all recorded readings.
    (iii) Conduct calibration and validation checks any time the 
detector exceeds the manufacturer's specifications or you install a new 
detector.
    (iv) At least monthly, inspect all components for integrity, all 
electrical connections for continuity, and all mechanical connections 
for leakage.
    (v) Record the results of each inspection, calibration, and 
validation check.


Sec.  63.1453  How do I demonstrate continuous compliance with the 
emission limitations, work practice standards, design standards, and 
operation and maintenance requirements that apply to me?

    (a) Filterable particulate matter emission limits. For each 
affected source subject to a particulate matter emission limit in Sec.  
63.1444 or Sec.  63.1446 as applies to you, you must demonstrate 
continuous compliance according to the requirements in paragraphs 
(a)(1) and (2) of this section.
    (1) For each copper concentrate dryer, smelting vessel, slag 
cleaning vessel, copper converter department, anode refining 
department, and combination of anode refining department and Hoboken 
converter process fugitive capture system subject to a filterable 
particulate matter emission limit in Sec.  63.1444 or Sec.  63.1446 as 
applies to you, you must demonstrate continuous compliance by meeting 
the conditions in paragraphs (a)(1)(i) through (iii) or paragraphs 
(a)(1)(i) and (iv) through (vii) of this section.
    (i) Maintain the average concentration of filterable particulate 
matter in the gases discharged from the affected source at or below the 
applicable emission limit. If a particulate matter continuous emissions 
monitoring system (PM CEMS) is used, you must demonstrate continued 
compliance according to the requirements in paragraphs (a)(1)(iv) 
through (vii) of this section.
    (ii) Monitor the operating parameter(s) established during the 
performance test according to the requirements in Sec. Sec.  63.1450(a) 
and 63.1452 and collect, reduce, and record the monitoring data for 
each of the operating limit parameters according to the applicable 
requirements of this subpart.
    (iii) Conduct subsequent performance tests following your initial 
performance test no less frequently than once per year according to the 
performance test procedures in Sec.  63.1450(a). New operating limits 
may be established during subsequent performance tests as long as the 
performance tests demonstrate compliance with the emission limits.
    (iv) Install, operate, and maintain a PM CEMS to measure and record 
PM concentrations and gas stream flow rates for the exhaust gases 
discharged to the atmosphere from each affected source subject to the 
emissions limit in this paragraph (a)(1). A single PM CEMS may be used 
for the combined exhaust gas streams from multiple affected sources at 
a point before the gases are discharged to the atmosphere. For each PM 
CEMS used to comply with this paragraph (a)(1), you must meet the 
requirements in this paragraph (a)(1)(iv) and paragraphs (a)(1)(v) 
through (vii) of this section.
    (v) You must install, certify, operate, and maintain the PM CEMS 
according to EPA Performance Specification 11 in appendix B to 40 CFR 
part 60, and the quality assurance requirements of Procedure 2 in 
appendix F to 40 CFR part 60.
    (vi) You must conduct an initial performance evaluation of the PM 
CEMS according to the requirements of Performance Specification 11 in 
appendix B to 40 CFR part 60. Thereafter, you must perform the 
performance evaluations as required by Procedure 2 in appendix F to 40 
CFR part 60.
    (vii) You must perform quarterly accuracy determinations and daily 
calibration drift tests for the PM CEMS according to Procedure 2 in 
appendix F to 40 CFR part 60.
    (2) For each smelting vessel, slag cleaning vessel, and copper 
converter department subject to the nonsulfuric acid particulate matter 
emission limit in Sec.  63.1444 as applies to you, you must demonstrate 
continuous compliance by meeting the conditions in paragraphs (a)(2)(i) 
through (iii) of this section.
    (i) Maintain the average concentration of nonsulfuric acid 
particulate matter in the process off-gas discharged from the affected 
source at or below 6.2 mg/dscm.
    (ii) Monitor the operating parameter established during the 
performance tests according to the requirements in Sec. Sec.  
63.1450(b) and 63.1452 and collect, reduce, and record the monitoring 
data for each of the operating limit parameters according to the 
applicable requirements of this subpart.
    (iii) Conduct subsequent performance tests following your initial 
performance test no less frequently than once per year according to the 
performance test procedures in Sec.  63.1450(b). New operating limits 
may be established during subsequent performance tests as long as the 
performance tests demonstrate compliance with the emission limits.

[[Page 41709]]

    (b) Copper converter department capture systems. You must 
demonstrate continuous compliance of the copper converter department 
capture system by meeting the requirements in paragraphs (b)(1) through 
(4) of this section.
    (1) Operate the copper converter department capture system at all 
times during blowing at or above the lowest values or settings 
established for the operating limits and demonstrated to achieve the 
opacity limit according to the applicable requirements of this subpart;
    (2) Inspect and maintain the copper converter department capture 
system according to the applicable requirements in Sec.  63.1447 and 
recording all information needed to document conformance with these 
requirements;
    (3) Monitor the copper converter department capture system 
according to the requirements in Sec.  63.1452(a) and collecting, 
reducing, and recording the monitoring data for each of the operating 
limit parameters according to the applicable requirements of this 
subpart; and
    (4) Conduct subsequent performance tests according to the 
requirements of Sec.  63.1450(c) following your initial performance 
test no less frequently than once per year to demonstrate that the 
opacity of any visible emissions exiting the roof monitors or roof 
exhaust fans on the building housing the copper converter department 
does not exceed 4 percent opacity.
    (c) Baghouses. For each baghouse subject to the operating limit for 
the bag leak detection system alarm in Sec.  63.1444(i) or Sec.  
63.1446(c), you must demonstrate continuous compliance by meeting the 
requirements in paragraphs (c)(1) through (3) of this section.
    (1) Maintain the baghouse such that the bag leak detection system 
alarm does not sound for more than 5 percent of the operating time 
during any semiannual reporting period. To determine the percent of 
time the alarm sounded use the procedures in paragraphs (c)(1)(i) 
through (v) of this section.
    (i) Alarms that occur due solely to a malfunction of the bag leak 
detection system are not included in the calculation.
    (ii) Before November 12, 2024, alarms that occur during startup, 
shutdown, or malfunction are not included in the calculation if the 
condition is described in the startup, shutdown, and malfunction plan, 
and you operated the source during such periods in accordance with 
Sec.  63.6(e)(1). On or after November 12, 2024, alarms that occur due 
solely to a malfunction of the bag leak detection system are not 
included in the calculation.
    (iii) Count 1 hour of alarm time for each alarm when you initiated 
procedures to determine the cause of the alarm within 1 hour.
    (iv) Count the actual amount of time you took to initiate 
procedures to determine the cause of the alarm if you did not initiate 
procedures to determine the cause of the alarm within 1 hour of the 
alarm.
    (v) Calculate the percentage of time the alarm on the bag leak 
detection system sounds as the ratio of the sum of alarm times to the 
total operating time multiplied by 100.
    (2) Maintain records of the times the bag leak detection system 
alarm sounded, and for each valid alarm, the time you initiated 
corrective action, the corrective action(s) taken, and the date on 
which corrective action was completed.
    (3) Inspect and maintain each baghouse according to the 
requirements in Sec.  63.1452(b)(2) and recording all information 
needed to document conformance with these requirements. If you increase 
or decrease the sensitivity of the bag leak detection system beyond the 
limits specified in Sec.  63.1452(b)(1)(vi), you must include a copy of 
the required written certification by a responsible official in the 
next semiannual compliance report.
    (d) Venturi wet scrubbers. For each venturi wet scrubber subject to 
the operating limits for pressure drop and scrubber water flow rate in 
Sec.  63.1444(j) or Sec.  63.1446(d), you must demonstrate continuous 
compliance by meeting the requirements of paragraphs (d)(1) through (3) 
of this section.
    (1) Maintain the hourly average pressure drop and scrubber water 
flow rate at levels no lower than those established during the initial 
or subsequent performance test;
    (2) Inspect and maintain each venturi wet scrubber CPMS according 
to Sec.  63.1452(c) and recording all information needed to document 
conformance with these requirements; and
    (3) Collect and reduce monitoring data for pressure drop and 
scrubber water flow rate according to Sec.  63.1452(e) and recording 
all information needed to document conformance with these requirements.
    (e) Other control devices. For each control device other than a 
baghouse or venturi wet scrubber subject to the operating limits for 
site-specific operating parameters in Sec.  63.1444(k) or Sec.  
63.1446(e), you must demonstrate continuous compliance by meeting the 
requirements of paragraphs (e)(1) through (3) of this section:
    (1) Maintain the hourly average rate at levels no lower than those 
established during the initial or subsequent performance test;
    (2) Inspect and maintain each CPMS operated according to Sec.  
63.1452(d) and record all information needed to document conformance 
with these requirements; and
    (3) Collect and reduce monitoring data for selected parameters 
according to Sec.  63.1452(e) and recording all information needed to 
document conformance with these requirements.
    (f) Fugitive dust sources. For each fugitive dust source subject to 
work practice standards in Sec.  63.1445, you must demonstrate 
continuous compliance by implementing all of fugitive control measures 
specified for the source in your written fugitive dust control plan.
    (g) Mercury emissions. For each affected source subject to mercury 
emissions limit in Sec.  63.1444 as applies to you must demonstrate 
continuous compliance according to the requirements in paragraph (g)(1) 
or paragraphs (g)(2) and (3) of this section.
    (1) Maintain the average concentration of mercury discharged from 
the facility at or below the emission limit in Sec.  63.1444 monitored 
by a mercury continuous emissions monitoring system (Hg CEMS). If the 
Hg CEMS is used, you must demonstrate continuous compliance according 
to the requirements in paragraphs (g)(1)(i) through (v) of this 
section.
    (i) Install and operate a Hg CEMS in accordance with Performance 
Specification 12A (PS 12A) of appendix B to 40 CFR part 60.
    (ii) Maintain each Hg CEMS according to the quality assurance 
requirements in Procedure 5 of appendix F to 40 CFR part 60. The 
relative accuracy testing of Hg CEMS must be conducted at normal 
operating conditions.
    (iii) Use a span value for any Hg CEMS that represents the mercury 
concentration corresponding to approximately two times the emissions 
standard and may be rounded up to the nearest multiple of 5 [mu]g/m3 of 
total mercury or higher level if necessary to include Hg concentrations 
which may occur.
    (iv) Determine the average on a 6-hour rolling basis.
    (v) Install, operate, calibrate, and maintain an instrument for 
continuously measuring and recording the exhaust gas flow rate to the 
atmosphere.
    (2) Monitor the operating parameter established during the 
performance tests

[[Page 41710]]

according to the requirements in Sec. Sec.  63.1450(d) and 63.1452 and 
collecting, reducing, and recording the monitoring data for each of the 
operating limit parameters according to the applicable requirements of 
this subpart.
    (3) Conduct subsequent performance tests following your initial 
performance test no less frequently than once per year according to the 
performance test procedures in Sec.  63.1450(d). New operating limits 
may be established during subsequent performance tests as long as the 
performance tests demonstrate compliance with the emission limits.
    (h) Process fugitive filterable particulate matter and lead from 
roofline vents. For emissions from roofline vents associated with the 
smelting vessels, slag cleaning vessels, copper converter department, 
and anode refining department subject to a filterable particulate 
matter emission limit in Sec.  63.1444(h), and for emissions from the 
combination of roofline vents associated with the Peirce-Smith 
converter department, Inco flash furnace, and anode refining department 
subject to a lead emission limit in Sec.  63.1444(p), you must 
demonstrate continuous compliance according to the requirements in 
paragraph (h)(1) or (2) and paragraph (h)(3) of this section. For the 
applicable design standards in Sec.  63.1444(p), you must demonstrate 
continuous compliance according to the requirements in paragraphs 
(h)(4) through (6) of this section.
    (1) Operating parameter. You must demonstrate continuous compliance 
with the established site-specific operating limit for a parameter, 
like opacity, based on values measured during the performance test you 
conduct to demonstrate initial compliance. If the operating parameter 
is visible emissions (VE) at each roofline vent, you must meet the 
requirements in paragraphs (h)(1)(i) through (v) of this section.
    (i) Perform daily VE observations of each roofline vent according 
to the procedures of Method 22 of appendix A-7 to 40 CFR part 60. You 
must conduct the Method 22 test while the affected source is operating 
under normal conditions. The duration of each Method 22 test must be at 
least 15 minutes.
    (ii) If VE are observed during any daily test conducted using 
Method 22 of appendix A-7 to 40 CFR part 60, you must promptly conduct 
an opacity test, according to the procedures of Method 9 of appendix A-
4 to 40 CFR part 60. ASTM D7520-16 (incorporated by reference, see 
Sec.  63.14) is an acceptable alternative to EPA Method 9 with the 
specified conditions in Sec.  63.1450(c)(3)(i)(A) through (E).
    (iii) You may decrease the frequency of Method 22 testing from 
daily to weekly for a roofline vent if one of the conditions in 
paragraph (h)(1)(iii)(A) or (B) of this section is met.
    (A) No VE are observed in 30 consecutive daily Method 22 tests for 
any roofline vent; or
    (B) No opacity greater than the site-specific operating limit is 
observed during any of the tests under Method 9 of appendix A-4 to 40 
CFR part 60 for any roofline vent.
    (iv) If VE are observed during any weekly test and opacity greater 
than the site-specific operating limit is observed in the subsequent 
test under Method 9 of appendix A-4 to 40 CFR part 60, you must 
promptly initiate and complete corrective actions according to your 
operation, maintenance, and monitoring plan (OM&M) plan, resume testing 
of that roof vent following Method 22 of appendix A-7 to 40 CFR part 
60, on a daily basis, as described in paragraph (h)(1)(i) of this 
section, and maintain that schedule until one of the conditions in 
paragraph (h)(1)(iii)(A) or (B) of this section is met, at which time 
you may again decrease the frequency of Method 22 testing to a weekly 
basis.
    (v) If greater than the site-specific opacity operating limit is 
observed during any test conducted using Method 9 of appendix A-4 to 40 
CFR part 60, you must report these deviations by following the 
requirements in Sec.  63.1455.
    (2) Monitor the site-specific operating parameter established 
during the performance tests according to the requirements in Sec.  
63.1450(e) for filterable particulate matter and Sec.  63.1450(g) for 
lead if applicable, and Sec.  63.1452, collect, reduce, and record the 
monitoring data for each of the operating limit parameters according to 
the applicable requirements of this subpart.
    (3) Conduct subsequent performance tests following your initial 
performance test no less frequently than once per year according to the 
performance test procedures in Sec.  63.1450(e) for filterable 
particulate matter and Sec.  63.1450(g) for lead if applicable. New 
operating limits may be established during subsequent performance tests 
as long as the performance tests demonstrate compliance with the 
emission limits.
    (4) For your flash furnace capture system, you must inspect the 
hooding, walls, and damper quarterly.
    (5) For your fuming ladle capture system, you must inspect the 
hooding, walls, and ladle during maintenance periods.
    (6) For your anode furnace secondary hood capture and control 
system, you must inspect the hood, walls, and damper during maintenance 
periods, and operate anode furnace secondary hood system at all times 
the anode furnaces are operating.
    (i) Benzene, toluene, chlorine, hydrogen chloride, polycyclic 
aromatic hydrocarbons excluding naphthalene, naphthalene, and dioxins/
furans emissions. For each affected source subject to the benzene, 
toluene, chlorine, hydrogen chloride, polycyclic aromatic hydrocarbons 
excluding naphthalene, naphthalene, and dioxins/furans emission limits 
in table 2 to this subpart, you must demonstrate continuous compliance 
according to paragraphs (i)(1) and (2) to this section.
    (1) You must monitor the site-specific operating parameter 
established during the performance tests according to the requirements 
in Sec.  63.1450(f) and collect, reduce, and record the monitoring data 
for each of the operating limit parameters according to the applicable 
requirements of this subpart.
    (2) You must demonstrate continuous compliance by conducting 
subsequent performance tests following your initial performance test at 
least once every five years according to the performance test 
procedures in Sec.  63.1450(f). New operating limits may be established 
during subsequent performance tests as long as the performance tests 
demonstrate compliance with the emission limits.


Sec.  63.1454  What notifications must I submit and when?

    (a) You must submit all of the notifications in Sec. Sec.  
63.6(h)(4) and (5), 63.7(b) and (c), 63.8(f)(4), and 63.9(b) through 
(h) that apply to you by the specified dates.
    (b) As specified in Sec.  63.9(b)(2), if you start your affected 
source before June 12, 2002, you must submit your initial notification 
not later than October 10, 2002, or no later than 120 days after the 
source becomes subject to this subpart (see Sec.  63.1441), whichever 
is later.
    (c) As specified in Sec.  63.9(b)(3), if you start your new 
affected source on or after June 12, 2002, you must submit your initial 
notification not later than 120 calendar days after you become subject 
to this subpart (see Sec.  63.1441).
    (d) If you are required to conduct a performance test, you must 
submit a notification of intent to conduct a performance test at least 
60 calendar days before the performance test is scheduled to begin as 
required in Sec.  63.7(b)(1).
    (e) If you are required to conduct a performance test, opacity 
observation,

[[Page 41711]]

or other initial compliance demonstration, you must submit a 
notification of compliance status according to Sec.  63.9(h)(2)(ii) by 
the date specified in paragraph (e)(1) or (2) of this section as 
applies to you.
    (1) For each initial compliance demonstration that does not include 
a performance test, you must submit the notification of compliance 
status before the close of business on the 30th calendar day following 
the completion of the initial compliance demonstration.
    (2) For each initial compliance demonstration that includes a 
performance test, you must submit the notification of compliance 
status, including the performance test results, before the close of 
business on the 60th calendar day following the completion of the 
performance test according to Sec.  63.10(d)(2).


Sec.  63.1455  What reports must I submit and when?

    (a) You must submit each report in paragraphs (a)(1) and (2) of 
this section that applies to you.
    (1) You must submit a compliance report semiannually according to 
the requirements in paragraph (b) of this section and containing the 
information in paragraph (c) of this section.
    (2) Before November 12, 2024, you must submit an immediate startup, 
shutdown, and malfunction report if you had a startup, shutdown, or 
malfunction during the reporting period that is not consistent with 
your startup, shutdown, and malfunction plan. You must report the 
actions taken for the event by fax or telephone within 2 working days 
after starting actions inconsistent with the plan. You must submit the 
information in Sec.  63.10(d)(5)(ii) by letter within 7 working days 
after the end of the event unless you have made alternative 
arrangements with the delegated authority. On or after November 12, 
2024, you must report any deviation from an applicable standard in 
Sec. Sec.  63.1444, 63.1445, and 63.1446 as part of your semiannual 
compliance report and include the information required in paragraph (c) 
of this section. In an event of an emergency situation, you must report 
the emergency and the actions taken for the event by email or telephone 
within 2 working days of the time when emissions limitations were 
exceeded due to the emergency (or an alternate timeframe acceptable to 
the delegated authority). For the purposes of complying with this 
paragraph (a)(2), an emergency situation is any situation arising from 
sudden and reasonably unforeseeable events beyond the control of the 
facility owner or operator that requires immediate corrective action to 
restore normal operation, and that causes the affected source to exceed 
an applicable emissions limitation under this subpart, due to 
unavoidable increases in emissions attributable to the emergency. An 
emergency must not include noncompliance to the extent it is caused by 
improperly designed equipment, lack of preventive maintenance, careless 
or improper operation, or operator error. You must submit the report 
within 7 working days after the end of the event unless you have made 
alternative arrangements with the delegated authority. This report must 
contain a description of the emergency, any steps take to mitigate the 
emissions and corrective actions taken.
    (b) Unless the Administrator has approved a different schedule 
under Sec.  63.10(a), you must submit each compliance report required 
in paragraph (a) of this section according to the applicable 
requirements in paragraphs (b)(1) through (5) of this section following 
the procedures in Sec.  63.9(k).
    (1) The first compliance report must cover the period beginning on 
the compliance date that is specified for your affected source in Sec.  
63.1443 and ending on June 30 or December 31, whichever date comes 
first after the compliance date that is specified for your source in 
Sec.  63.1443.
    (2) The first compliance report must be delivered no later than 
July 31 or January 31, whichever date comes first after your first 
compliance report is due.
    (3) Each subsequent compliance report must cover the semiannual 
reporting period from January 1 through June 30 or the semiannual 
reporting period from July 1 through December 31.
    (4) Each subsequent compliance report must be delivered no later 
than July 31 or January 31, whichever date comes first after the end of 
the semiannual reporting period.
    (5) For each affected source that is subject to permitting 
regulations pursuant to 40 CFR part 70 or 71, and if the delegated 
authority has established dates for submitting semiannual reports 
pursuant to 40 CFR 70.6(a)(3)(iii)(A) or 71.6(a)(3)(iii)(A), you may 
submit the first and subsequent compliance reports according to the 
dates the delegated authority has established instead of according to 
the dates in paragraphs (b)(1) through (4) of this section.
    (c) Each compliance report must contain the information in 
paragraphs (c)(1) through (3) of this section and, as applicable, 
paragraphs (c)(4) through (8) of this section.
    (1) Company name and address.
    (2) Statement by a responsible official, as defined in Sec.  63.2, 
with that official's name, title, and signature, certifying the 
accuracy and completeness of the content of the report.
    (3) Date of report and beginning and ending dates of the reporting 
period.
    (4) Before November 12, 2024, if you had a startup, shutdown or 
malfunction during the reporting period and you took actions consistent 
with your startup, shutdown, and malfunction plan, the compliance 
report must include the information in Sec.  63.10(d)(5)(i). On or 
after November 12, 2024, you are not required to have a startup, 
shutdown, and malfunction plan and you are not required to include in 
your report the information in Sec.  63.10(d)(5)(i).
    (5) If there are no deviations from any emission limitations 
(emission limit, operating limit, opacity limit) that applies to you 
and there are no deviations from the requirements for work practice 
standards in this subpart, a statement that there were no deviations 
from the emission limitations, work practice standards, or operation 
and maintenance requirements during the reporting period.
    (6) If there were no periods during which an operating parameter 
monitoring system was out-of-control as specified in Sec.  63.8(c)(7), 
a statement that there were no periods during which the monitoring 
system was out-of-control during the reporting period.
    (7) For each deviation from an emission limitation (emission limit, 
operating limit, opacity limit) and for each deviation from the 
requirements for work practice standards that occurs at an affected 
source where you are not using a continuous monitoring system to comply 
with the emission limitations or work practice standards in this 
subpart, the compliance report must contain the information in 
paragraphs (c)(1) through (4) of this section and the information in 
paragraphs (c)(7)(i) and (ii) of this section.
    (i) The total operating time of each affected source during the 
reporting period.
    (ii) Information on the number, date, time, duration, and cause of 
deviations (including unknown cause, if applicable), as applicable, the 
corrective action taken, 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.
    (8) For each deviation from an emission limitation (emission limit,

[[Page 41712]]

operating limit, opacity limit, and visible emission limit) occurring 
at an affected source where you are using an operating parameter 
monitoring system to comply with the emission limitation in this 
subpart, you must include the information in paragraphs (c)(1) through 
(4) of this section and the information in paragraphs (c)(8)(i) through 
(xi) of this section.
    (i) The cause of each deviations (including unknown cause, if 
applicable), the corrective action taken, 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.
    (ii) If the monitoring system was inoperative, the date and time 
that each monitoring system was inoperative, except for zero (low-
level) and high-level checks.
    (iii) If the monitoring system was inoperative, the date, time and 
duration that each monitoring system was out-of-control, including the 
information in Sec.  63.8(c)(8).
    (iv) The number, date and time that each deviation started and 
stopped.
    (v) A summary of the total duration of the deviation during the 
reporting period and the total duration as a percent of the total 
source operating time during that reporting period.
    (vi) A breakdown of the total duration of the deviations during the 
reporting period into those that are due to control equipment problems, 
process problems, other known causes, and other unknown causes.
    (vii) A summary of the total duration of monitoring system downtime 
during the reporting period and the total duration of monitoring system 
downtime as a percent of the total source operating time during that 
reporting period.
    (viii) A brief description of the process units.
    (ix) A brief description of the monitoring system.
    (x) The date of the latest monitoring system certification or 
audit.
    (xi) A description of any changes in continuous monitoring systems, 
processes, or controls since the last reporting period.
    (d) If you have obtained a title V operating permit pursuant to 40 
CFR part 70 or 71 must report all deviations as defined in this subpart 
in the semiannual monitoring report required by 40 CFR 
70.6(a)(3)(iii)(A) or 71.6(a)(3)(iii)(A). If you submit a compliance 
report pursuant to paragraph (a) of this section along with, or as part 
of, the semiannual monitoring report required by 40 CFR 
70.6(a)(3)(iii)(A) or 71.6(a)(3)(iii)(A), and the compliance report 
includes all required information concerning deviations from any 
emission limitation (including any operating limit), or work practice 
requirement in this subpart, submission of the compliance report is 
deemed to satisfy any obligation to report the same deviations in the 
semiannual monitoring report. However, submission of a compliance 
report does not otherwise affect any obligation you may have to report 
deviations from permit requirements to the permit authority.
    (e) Within 60 days after the date of completing each performance 
test or continuous monitoring system (CMS) performance evaluation (as 
defined in Sec.  63.2) required by this subpart, the owner or operator 
must submit the results of the performance test or performance 
evaluation following the procedures specified in Sec.  63.9(k).
    (1) Data collected using test methods supported by the EPA's 
Electronic Reporting Tool (ERT) as listed on the EPA's ERT website 
(https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert) at the time of the test. Submit the results of the 
performance test or the performance evaluation of CMS measuring 
relative accuracy test audit (RATA) pollutants to the EPA via the 
Compliance and Emissions Data Reporting Interface (CEDRI), which can be 
accessed through the EPA's Central Data Exchange (CDX) (https://cdx.epa.gov/). The data must be submitted in a file format generated 
through the use of the EPA's ERT. Alternatively, you may submit an 
electronic file consistent with the extensible markup language (XML) 
schema listed on the EPA's ERT website.
    (2) Data collected using test methods that are not supported by the 
EPA's ERT as listed on the EPA's ERT website at the time of the test. 
The results of the performance test or the performance evaluation of 
CMS measuring RATA pollutants by methods that are not supported by the 
ERT, must be included as an attachment in the ERT or an alternate 
electronic file consistent with the XML schema listed on the EPA's ERT 
website. Submit the ERT generated package or alternative file to the 
EPA via CEDRI.


Sec.  63.1456  What records must I keep and how long must I keep my 
records?

    (a) You must keep the records listed in paragraphs (a)(1) through 
(8) of this section.
    (1) A copy of each notification and report that you submitted to 
comply with this subpart, including all documentation supporting any 
initial notification or notification of compliance status that you 
submitted, according to the requirements in Sec.  63.10(b)(2)(xiv).
    (2) Before November 12, 2024, the records in Sec.  63.6(e)(3)(iii) 
through (v) related to startup, shutdown, and malfunction. On or after 
November 12, 2024, you are not required to keep the records required in 
Sec.  63.6(e)(3)(iii) through (v) related to compliance with a startup, 
shutdown, and malfunction plan.
    (3) Records of performance tests and performance evaluations as 
required in Sec.  63.10(b)(2)(viii).
    (4) For each monitoring system, you must keep the records specified 
in paragraphs (a)(4)(i) through (iv) of this section.
    (i) Records described in Sec.  63.10(b)(2)(vi) through (xi).
    (ii) Monitoring data recorded by the monitoring system during a 
performance evaluation as required in Sec.  63.6(h)(7)(i) and (ii).
    (iii) Before November 12, 2024, previous (i.e., superseded) 
versions of the performance evaluation plan as required in Sec.  
63.8(d)(3). On or after November 12, 2024, you must comply with the 
requirements in Sec.  63.8(d)(1) and (2). The owner or operator shall 
keep the written procedures required in Sec.  63.8(d)(1) and (2) on 
record for the life of the affected source or until the affected source 
is no longer subject to the provisions of this part, to be made 
available for inspection, upon request, by the Administrator. If the 
performance evaluation plan is revised, the owner or operator shall 
keep previous (i.e., superseded) versions of the performance evaluation 
plan on record to be made available for inspection, upon request, by 
the Administrator, for a period of 5 years after each revision to the 
plan. The program of corrective action should be included in the plan 
required under Sec.  63.8(d)(2).
    (iv) Before November 12, 2024, records of the date and time that 
each deviation started and stopped, and whether the deviation occurred 
during a period of startup, shutdown, or malfunction or during another 
period. On or after November 12, 2024, for each failure to meet an 
applicable standard, you must record the information in paragraphs 
(a)(4)(iv)(A) through (D) of this section. Examples of such methods to 
estimate emissions include product-loss calculations, mass balance 
calculations, measurements, or

[[Page 41713]]

engineering judgment based on known process parameters.
    (A) The occurrence and duration of each startup, shutdown, or 
malfunction of process, air pollution control, and monitoring 
equipment.
    (B) In the event that an affected unit fails to meet an applicable 
standard, record the number of failures. For each failure record the 
date, time, cause and duration of each failure.
    (C) For each failure to meet an applicable standard, record and 
retain a list of the affected sources or equipment, whether the failure 
occurred during a period of startup, shutdown or malfunction, actions 
taken to minimize emissions, 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.
    (D) Record actions taken to minimize emissions in accordance with 
Sec.  63.1447(a), and any corrective actions taken to return the 
affected unit to its normal or usual manner of operation.
    (5) For each performance test you conduct to demonstrate compliance 
with an opacity limit according to Sec.  63.1450(c), you must keep the 
records specified in paragraphs (a)(5)(i) through (ix) of this section.
    (i) Dates and time intervals of all opacity observation period 
segments;
    (ii) Description of overall smelter operating conditions during 
each observation period. Identify, if any, the smelter copper 
production process equipment that was out-of-service during the 
performance test and explain why this equipment was not in operation;
    (iii) Name, affiliation, and copy of current visible emission 
reading certification for each visible emission observer participating 
in the performance test;
    (iv) Name, title, and affiliation for each indoor process monitor 
participating in the performance test;
    (v) Copies of all visible emission observer opacity field data 
sheets;
    (vi) Copies of all indoor process monitor operating log sheets;
    (vii) Copies of all data summary sheets used for data reduction;
    (viii) Copy of calculation sheets of the average opacity value used 
to demonstrate compliance with the opacity limit; and
    (ix) Documentation according to the requirements in Sec.  
63.1450(c)(9)(iv) to support your selection of the site-specific 
capture system operating limits used for each batch copper converter 
capture system when blowing.
    (6) For each baghouse subject to the operating limit in Sec.  
63.1444(i) or Sec.  63.1446(c), you must keep the records specified in 
paragraphs (a)(6)(i) and (ii) of this section.
    (i) Records of alarms for each bag leak detection system.
    (ii) Description of the corrective actions taken following each bag 
leak detection alarm.
    (7) For each control device other than a baghouse or venturi wet 
scrubber subject to site-specific operating limits in Sec.  63.1444(k) 
or Sec.  63.1446(e), you must keep documentation according to the 
requirements in Sec.  63.1450(a)(5)(iv) to support your selection of 
the site-specific operating limits for the control device.
    (8) You must keep records of bypass stack usage, including the flow 
rate and operating parameter(s).
    (b) Your records must be in a form suitable and readily available 
for expeditious review, according to Sec.  63.10(b)(1).
    (c) As specified in Sec.  63.10(b)(1), you must keep each record 
for 5 years following the date of each occurrence, measurement, 
maintenance, corrective action, report, or record.
    (d) You must keep each record on site for at least 2 years after 
the date of each occurrence, measurement, maintenance, corrective 
action, report, or record, according to Sec.  63.10(b)(1). You can keep 
the records off site for the remaining 3 years.


Sec.  63.1457  What part of the general provisions apply to me?

    Table 1 to this subpart shows which parts of the general provisions 
in Sec. Sec.  63.1 through 63.15 apply to you.


Sec.  63.1458  Who implements and enforces this subpart?

    (a) This subpart can be implemented and enforced by us, the United 
States Environmental Protection Agency (U.S. EPA), or a delegated 
authority such as your State, local, or tribal agency. If the U.S. EPA 
Administrator has delegated authority to your State, local, or tribal 
agency, then that agency has the authority to implement and enforce 
this subpart. You should contact your U.S. EPA Regional Office to find 
out if this subpart is delegated to your State, local, or tribal 
agency.
    (b) In delegating implementation and enforcement authority of this 
subpart to a State, local, or tribal agency under subpart E of this 
part, the authorities listed in paragraph (c) of this section are 
retained by the U.S. EPA Administrator and are not transferred to the 
State, local, or tribal agency.
    (c) The authorities that will not be delegated to State, local, or 
tribal agencies are as listed in paragraphs (c)(1) through (5) of this 
section.
    (1) Approval of alternatives to the emission limitations and work 
practice standards in Sec. Sec.  63.1444 through 63.1446 under Sec.  
63.6(g).
    (2) Approval of major alternatives to test methods under Sec.  
63.7(f) and as defined in Sec.  63.90.
    (3) Approval of major alternatives to monitoring under Sec.  
63.8(f) and as defined in Sec.  63.90.
    (4) Approval of major alternatives to recordkeeping and reporting 
under Sec.  63.10(f) and as defined in Sec.  63.90.
    (5) Approval of an alternative to any electronic reporting to the 
EPA required by this subpart.


Sec.  63.1459  What definitions apply to this subpart?

    Terms used in this subpart are defined in the Clean Air Act, in 
Sec.  63.2, and in this section as follows:
    Anode refining department means the area at a primary copper 
smelter in which anode copper refining operations are performed. 
Emission sources in the anode refining department include anode 
refining furnaces and utility vessels.
    Baghouse means a control device that collects particulate matter by 
filtering the gas stream through bags. A baghouse is also referred to 
as a ``fabric filter.''
    Bag leak detection system means a system that is capable of 
continuously monitoring relative particulate matter (dust) loadings in 
the exhaust of a baghouse in order to detect bag leaks and other upset 
conditions. A bag leak detection system includes, but is not limited 
to, an instrument that operates on triboelectric, light scattering, 
transmittance or other effect to continuously monitor relative 
particulate matter loadings.
    Batch copper converter means a Peirce-Smith converter or Hoboken 
converter in which copper matte is oxidized to form blister copper by a 
process that is performed in discrete batches using a sequence of 
charging, blowing, skimming, and pouring.
    Blowing means the operating mode for a batch copper converter 
during which air or oxygen-enriched air is injected into the molten 
converter bath.
    Bypass stack means a device used for discharging combustion gases 
to avoid severe damage to the air pollution control device or other 
equipment and conduct planned maintenance safely in accordance with the 
work practice standard in Sec.  63.1444(q). The use of a bypass stack 
during a performance test of a process or control device will 
invalidate the test.
    Capture system means the collection of components used to capture 
gases and fumes released from one or more

[[Page 41714]]

emission points, and to convey the captured gases and fumes to a 
control device. A capture system may include, but is not limited to, 
the following components as applicable to a given capture system 
design: duct intake devices, hoods, enclosures, ductwork, dampers, 
manifolds, plenums, and fans.
    Charging means the operating mode for a batch copper converter 
during which molten or solid material is added into the vessel.
    Control device means the air pollution control equipment used to 
collect particulate matter and other emissions from a gas stream.
    Converting vessel means a furnace, reactor, or other type of vessel 
in which copper matte is oxidized to form blister copper.
    Copper concentrate dryer means a vessel in which copper 
concentrates are heated in the presence of air to reduce the moisture 
content of the material. Supplemental copper-bearing feed materials and 
fluxes may be added or mixed with the copper concentrates fed to a 
copper concentrate dryer.
    Copper concentrate feed means the mixture of copper concentrate, 
secondary copper-bearing materials, recycled slags and dusts, fluxes, 
and other materials blended together for feeding to the smelting 
vessel.
    Copper converter department means the area at a primary copper 
smelter in which the copper converters are located. This could include 
a batch copper converter or other type of copper converter, such as a 
continuous copper converter.
    Copper matte means a material predominately composed of copper and 
iron sulfides produced by smelting copper ore concentrates.
    Deviation means any instance in which an affected source subject to 
this subpart, or an owner or operator of such a source:
    (1) Fails to meet any requirement or obligation established by this 
subpart including, but not limited to, any emission limitation 
(including any operating limit) or work practice standard;
    (2) Fails to meet any term or condition that is adopted to 
implement an applicable requirement in this subpart and that is 
included in the operating permit for any affected source required to 
obtain such a permit; or
    (3) Fails to meet any emission limitation (including any operating 
limit) or work practice standard in this subpart during startup, 
shutdown, or malfunction, regardless of whether or not such failure is 
permitted by this subpart.
    Emission limitation means any emission limit, opacity limit, 
operating limit, or visible emission limit.
    Fugitive dust material means copper concentrate, dross, reverts, 
slag, speiss, or other solid copper-bearing materials.
    Fugitive dust source means a stationary source of particulate 
matter emissions resulting from the handling, storage, transfer, or 
other management of fugitive dust materials where the source is not 
associated with a specific process, process vent, or stack. Examples of 
a fugitive dust source include, but are not limited to, on-site 
roadways used by trucks transporting copper concentrate, unloading of 
materials from trucks or railcars, outdoor material storage piles, and 
transfer of material to hoppers and bins.
    Holding means the operating mode for a batch copper converter or a 
holding furnace associated with a smelting vessel during which the 
molten bath is maintained in the vessel but no blowing or smelting is 
performed nor is material added into or removed from the vessel.
    New copper converter system means the copper matte is oxidized and 
forms copper blister by a process that is performed continuously. This 
system may include a flash smelting furnace, flash converting furnace, 
secondary gas system, a rotary dryer, anode area, matte grinding plant, 
hydrometallurgical plant and possibly an acid plant.
    Opacity means the degree to which emissions reduce the transmission 
of light.
    Particulate matter means any finely divided solid or liquid 
material, other than uncombined water, as measured by the specific 
reference method.
    Pouring means the operating mode for a batch copper converter 
during which molten copper is removed from the vessel.
    Primary copper smelter means any installation or any intermediate 
process engaged in the production of copper from copper sulfide ore 
concentrates through the use of pyrometallurgical techniques.
    Responsible official means responsible official as defined in 40 
CFR 70.2.
    Roofline vents means an exhaust system designed to evacuate process 
fugitive emissions that collect in the roofline area of various process 
buildings (e.g., smelting building roof vents, converter building roof 
vents, etc.).
    Secondary gas system means a capture system that collects the gases 
and fumes released when removing and transferring molten materials from 
one or more vessels using tapping ports, launders, and other openings 
in the vessels. Examples of molten material include, but are not 
limited to: Copper matte, slag, and blister copper.
    Skimming means the batch copper converter operating mode during 
which molten slag is removed from the vessel.
    Slag cleaning vessel means a vessel that receives molten copper-
bearing material and the predominant use of the vessel is to separate 
this material into molten copper matte and slag layers.
    Smelting vessel means a furnace, reactor, or other type of vessel 
in which copper ore concentrate and fluxes are smelted to form a molten 
mass of material containing copper matte and slag. Other copper-bearing 
materials may also be charged to the smelting furnace.
    TEQ means the international method of expressing toxicity 
equivalents for dioxins/furans as defined in EPA/100/R-10/005 
(incorporated by reference, see Sec.  63.14). The Toxic Equivalency 49 
Factors (TEFs) used to determine the dioxin and furan TEQs are listed 
in table 3 to this subpart.
    Work practice standard means any design, equipment, work practice, 
or operational standard, or combination thereof, that is promulgated 
pursuant to section 112(h) of the Clean Air Act.

Table 1 to Subpart QQQ of Part 63--Applicability of General Provisions 
to This Subpart

    As required in Sec.  63.1457, you must comply with the requirements 
of the NESHAP General Provisions (subpart A of this part) shown in the 
following table:

----------------------------------------------------------------------------------------------------------------
               Citation                        Subject          Applies to this subpart        Explanation
----------------------------------------------------------------------------------------------------------------
Sec.   63.1..........................  Applicability..........  Yes....................
Sec.   63.2..........................  Definitions............  Yes....................
Sec.   63.3..........................  Units and Abbreviations  Yes....................
Sec.   63.4..........................  Prohibited Activities..  Yes....................
Sec.   63.5..........................  Construction and         Yes....................
                                        Reconstruction.

[[Page 41715]]

 
Sec.   63.6(a) through (d), (e)(iii),  Compliance with          Yes....................
 and (f)(2) and (3), (g).               Standards and
                                        Maintenance
                                        Requirements.
Sec.   63.6(e)(1)(i).................  Operation and            Yes before November 12,  General duty
                                        Maintenance              2024. No on or after     requirements to
                                        Requirements.            November 12, 2024.       minimize emissions at
                                                                                          all times are
                                                                                          contained in Sec.
                                                                                          63.1447(a).
Sec.   63.6(e)(1)(ii)................  Requirement to correct   Yes before November 12,  Malfunctions are no
                                        malfunctions as soon     2024. No on or after     longer exempt.
                                        as practicable.          November 12, 2024.
Sec.   63.6(e)(2)....................  Reserved...............  No.....................
Sec.   63.6(e)(3)....................  Requirement to develop   Yes before November 12,  Startup, shutdown, and
                                        a startup, shutdown,     2024. No on or after     malfunction (SSM)
                                        and malfunction plan.    November 12, 2024.       plans are no longer
                                                                                          necessary.
Sec.   63.6(f)(1)....................  Compliance with          Yes before November 12,  Source category rules
                                        nonopacity emission      2024. No on or after     apply at all times.
                                        standards during         November 12, 2024.
                                        periods of startup,
                                        shutdown, and
                                        malfunction.
Sec.   63.6(h).......................  Determining compliance   No.....................  This subpart specifies
                                        with Opacity and VE                               the requirements and
                                        standards.                                        test protocol used to
                                                                                          determine compliance
                                                                                          with the opacity
                                                                                          limits.
Sec.   63.6(i) and (j)...............  Extension of Compliance  Yes....................
                                        and Presidential
                                        Compliance Exemption.
Sec.   63.7(a)(1) and (2)............  Applicability and        No.....................  This subpart specifies
                                        Performance Test Dates.                           performance test
                                                                                          applicability and
                                                                                          dates.
Sec.   63.7(a)(3), (b) through (d),    Performance Testing      Yes....................
 (f) through (h).                       Requirements.
Sec.   63.7(e)(1)....................  Performance Testing....  Yes before November 12,  See Sec.  Sec.
                                                                 2024. No on or after     63.1450 and 63.1444.
                                                                 November 12, 2024.
Sec.   63.8 except for (a)(4),         Monitoring Requirements  Yes....................
 (c)(1)(i) and (iii), (c)(4), (d)(3),
 and (f)(6).
Sec.   63.8(a)(4)....................  Additional Monitoring    No.....................  This subpart does not
                                        Requirements for                                  require flares.
                                        Control devices in
                                        Sec.   63.11.
Sec.   63.8(c)(1)(i) and (iii).......  Operation and            Yes before November 12,  Cross references to the
                                        Maintenance of and SSM   2024. No on or after     general duty and SSM
                                        plan for Continuous      November 12, 2024.       plan requirements in
                                        Monitoring Systems.                               those paragraphs are
                                                                                          no longer necessary.
Sec.   63.8(c)(4)....................  Continuous Monitoring    No.....................  This subpart specifies
                                        System Requirements.                              requirements for
                                                                                          operation of CMS.
Sec.   63.8(d)(3)....................  Quality Control Program  Yes before November 12,  See Sec.
                                                                 2024. No on or after     63.1456(a)(4)(iii).
                                                                 November 12, 2024.
Sec.   63.8(f)(6)....................  RATA Alternative.......  No.....................  This subpart does not
                                                                                          require continuous
                                                                                          emission monitoring
                                                                                          systems.
Sec.   63.9..........................  Notification             Yes....................
                                        Requirements.
Sec.   63.9(g)(5)....................  DATA reduction.........  No.....................  This subpart specifies
                                                                                          data reduction
                                                                                          requirements.
Sec.   63.10 except for (b)(2)(i),     Recordkeeping and        Yes....................
 (ii), (iv), (v), and (xiii), (c)(7),   reporting Requirements.
 (8), and (15), and (d)(5).
Sec.   63.10(b)(2)(i)................  General Recordkeeping    Yes before November 12,  No longer necessary
                                        Requirements during      2024. No on or after     because recordkeeping
                                        Startup and Shutdown.    November 12, 2024.       and reporting
                                                                                          applicable to normal
                                                                                          operations will apply
                                                                                          to startup and
                                                                                          shutdown.
Sec.   63.10(b)(2)(ii)...............  General Recordkeeping    Yes before November 12,  See Sec.
                                        Requirements during      2024. No on or after     63.1456(a)(4)(iv) for
                                        Startup, Shutdown, and   November 12, 2024.       recordkeeping
                                        Malfunction and                                   requirements for a
                                        Failures to Meet                                  deviation from a
                                        Standards.                                        standard.
Sec.   63.10(b)(2)(iv)...............  Actions Taken to         Yes before November 12,  See Sec.   63.1456 for
                                        Minimize Emissions       2024. No on or after     the recordkeeping
                                        during Startup,          November 12, 2024.       requirements of
                                        Shutdown, and                                     actions taken to
                                        Malfunction.                                      minimize emissions and
                                                                                          record corrective
                                                                                          actions.
Sec.   63.10(b)(2)(v)................  Actions Taken to         Yes before November 12,  Requirements to
                                        Minimize Emissions       2024. No on or after     document that actions
                                        during Startup,          November 12, 2024.       taken during SSM
                                        Shutdown, and                                     events are consistent
                                        Malfunction.                                      with SSM plan are no
                                                                                          longer required.
Sec.   63.10(b)(2)(xiii).............  CMS Records for RATA     No.....................  This subpart does not
                                        Alternative.                                      require continuous
                                                                                          emission monitoring
                                                                                          systems.

[[Page 41716]]

 
Sec.   63.10(c)(7)-(8)...............  Records of Excess        No.....................  This subpart specifies
                                        Emissions and                                     record keeping
                                        Parameter Monitoring                              requirements.
                                        Exceedances for CMS.
Sec.   63.10(c)(15)..................  Use of SSM Plan........  Yes before November 12,  This provision would be
                                                                 2024. No on or after     eliminated because it
                                                                 November 12, 2024.       referenced the
                                                                                          source's SSM plan,
                                                                                          which is no longer
                                                                                          required.
Sec.   63.10(d)(5)...................  SSM Reporting and        Yes before November 12,  See Sec.  Sec.
                                        Recordkeeping            2024. No on or after     63.1455(c)(4) and
                                        Requirements.            November 12, 2024.       63.1456.
Sec.   63.11.........................  Control Device           No.....................  This subpart does not
                                        Requirements.                                     require flares.
Sec.   63.12.........................  State Authority and      Yes....................
                                        Delegations.
Sec.  Sec.   63.13 through 63.16.....  Addresses,               Yes....................
                                        Incorporation by
                                        Reference,
                                        Availability of
                                        Information,
                                        Performance Track
                                        Provisions.
----------------------------------------------------------------------------------------------------------------

Table 2 to Subpart QQQ of Part 63--Non-Mercury HAP Emission Limits

    As required in Sec.  63.1444(o), you must meet each emission limit 
in the following table that applies to you.

------------------------------------------------------------------------
                                            You must meet the following
                For. . .                          emission limit
------------------------------------------------------------------------
Each new and existing combination of      Benzene emissions must not
 stacks or other vents from the copper     exceed 1.7E-03 lb/ton copper
 concentrate dryers, converting            concentrate feed charged to
 department, the anode refining            the smelting vessel.
 department, and the smelting vessels.
Each new and existing combination of      Toluene emissions must not
 stacks or other vents from the copper     exceed 8.4E-04 lb/ton copper
 concentrate dryers, converting            concentrate feed charged to
 department, the anode refining            the smelting vessel.
 department, and the smelting vessels.
Each new and existing combination of      Chlorine emissions must not
 stacks or other vents from the copper     exceed 5.4E-03 lb/ton copper
 concentrate dryers, converting            concentrate feed charged to
 department, the anode refining            the smelting vessel.
 department, and the smelting vessels.
Each new and existing combination of      Hydrogen chloride emissions
 stacks or other vents from the copper     must not exceed 1.5E-03 lb/
 concentrate dryers, converting            ton copper concentrate feed
 department, the anode refining            charged to the smelting
 department, and the smelting vessels.     vessel.
Each new and existing combination of      Polycyclic aromatic
 stacks or other vents from the copper     hydrocarbons (excluding
 concentrate dryers, converting            naphthalene) emissions must
 department, the anode refining            not exceed 1.0E-04 lb/ton
 department, and the smelting vessels.     copper concentrate feed
                                           charged to the smelting
                                           vessel.
Each new and existing combination of      Naphthalene emissions must not
 stacks or other vents from the copper     exceed 2.8E-04 lb/ton copper
 concentrate dryers, converting            concentrate feed charged to
 department, the anode refining            the smelting vessel.
 department, and the smelting vessels.
Each new and existing combination of      Dioxins/Furans emissions \1\
 stacks or other vents from the copper     must not exceed 6.0E+01 ng
 concentrate dryers, converting            TEQ/Mg copper concentrate
 department, the anode refining            feed charged to the smelting
 department, and the smelting vessels.     vessel.
------------------------------------------------------------------------
\1\ Determined using the toxic equivalency factors listed in Table 2 of
  Recommended Toxicity Equivalence Factors (TEFs) for Human Health Risk
  Assessments of 2, 3, 7, 8- Tetrachlorodibenzo-p-dioxin and Dioxin-Like
  Compounds (incorporated by reference, see Sec.   63.14).


Table 3 to Subpart QQQ of Part 63--2010 Toxic Equivalency Factors (TEFs)
------------------------------------------------------------------------
                                                                  TEF
                          Congener                             (mammals)
------------------------------------------------------------------------
2,3,7,8-Te CDD..............................................           1
1,2,3,7,8-Pe CDD............................................           1
1,2,3,4,7,8-HxCDD...........................................         0.1
1,2,3,6,7,8-HxCDD...........................................         0.1
1,2,3,7,8,9-HxCDD...........................................         0.1
1,2,3,4,6,7,8-HpCDD.........................................        0.01
OCDD........................................................      0.0003
2,3,7,8-Te CDF..............................................         0.1
1,2,3,7,8-Pe CDF............................................        0.03
2,3,4,7,8-Pe CDF............................................         0.3
1,2,3,4,7,8-HxCDF...........................................         0.1
1,2,3,6,7,8-HxCDF...........................................         0.1
2,3,4,6,7,8-HxCDF...........................................         0.1
1,2,3,7,8,9-HxCDF...........................................         0.1
1,2,3,4,6,7,8-HpCDF.........................................        0.01
1,2,3,4,7,8,9-HpCDF.........................................        0.01
OCDF........................................................      0.0003
------------------------------------------------------------------------


[[Page 41717]]


      Table 4 to Subpart QQQ of Part 63--Compliance Dates for Amendments Being Promulgated on May 13, 2024
----------------------------------------------------------------------------------------------------------------
                                                                                       And the owner or operator
 If the construction/reconstruction date    Then the owner or operator must comply     must achieve compliance .
                is . . .                                  with . . .                              . .
----------------------------------------------------------------------------------------------------------------
On or before January 11, 2022...........  Requirements for existing sources in Sec.   On or before May 13, 2025.
                                           Sec.   63.1444(f)(2) and (3), (l);
                                           63.1446; 63.1449; \1\ 63.1450(a) and (d);
                                           and 63.1451 through 63.1456, as
                                           applicable.
                                          Requirements for existing sources in Sec.   On or before May 13, 2026.
                                           Sec.   63.1444(h); 63.1449; \1\
                                           63.1450(e); and 63.1451 through 63.1456,
                                           as applicable.
After January 11, 2022..................  Requirements for new sources in Sec.  Sec.  Upon initial startup or
                                             63.1444(e)(1) and (2), (f)(2) and (3),    May 13, 2024, whichever
                                           (h), (m); 63.1446; 63.1449; \1\             is later.
                                           63.1450(a), (d), (e); and 63.1451 through
                                           63.1456, as applicable.
On or before July 24, 2023..............  Requirements for existing sources in Sec.   On or before May 13, 2027.
                                           Sec.   63.1444(g); 63.1449; \1\
                                           63.1450(a); and 63.1451 through 63.1456,
                                           as applicable.
                                          Requirements for existing sources in Sec.   On or before May 13, 2025.
                                           Sec.   63.1444(o); 63.1449; \1\
                                           63.1450(f); and 63.1451 through 63.1456,
                                           as applicable.
                                          Requirements for existing sources in Sec.   On or before November 12,
                                           Sec.   63.1444(q); 63.1449; \1\             2024.
                                           63.1450(a), (g); and 63.1451 through
                                           63.1456, as applicable.
After July 24, 2023.....................  Requirements for new sources in Sec.  Sec.  Upon initial startup or
                                             63.1444(o), (q); 63.1449; \1\             May 13, 2024, whichever
                                           63.1450(a), (f), (g); and 63.1451 through   is later.
                                           63.1456, as applicable.
On or before May 13, 2024...............  Requirements for existing sources in Sec.   On or before May 13, 2027.
                                           Sec.   63.1444(p); 63.1449; \1\
                                           63.1450(g); and 63.1451 through 63.1456,
                                           as applicable.
----------------------------------------------------------------------------------------------------------------
\1\ Section 63.1449(a) provides that any necessary performance test is conducted within 180 days of the
  compliance date.


                               Figure 1 to Subpart QQQ of Part 63--Data Summary Sheet for Determination of Average Opacity
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                                                                                                                                   Average opacity for 1-
                                                                                                              Visible emissions       minute interval
                                      Number of converters       Converter aisle     Average opacity for 1- interference observed     blowing without
             Clock time                      blowing                activity            minute interval        during 1-minute        visible emission
                                                                                           (percent)        interval? (yes or no)      interferences
                                                                                                                                         (percent)
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Subpart EEEEEE--National Emission Standards for Hazardous Air 
Pollutants for Primary Copper Smelting Area Sources

0
5. Amend Sec.  63.11147 by revising paragraphs (b)(6), (c)(1) and (5), 
(d), and (e) to read as follows:


Sec.  63.11147  What are the standards and compliance requirements for 
existing sources not using batch copper converters?

* * * * *
    (b) * * *
    (6) You must submit to the permitting authority by the 20th day of 
each month a report summarizing the 24-hour average mass 
PM10 emissions rates for the previous month. Beginning 
November 12, 2024, the owner or operator must electronically submit all 
subsequent reports in PDF format to the EPA via CEDRI, which can be 
accessed through EPA's CDX (https://cdx.epa.gov/) following the 
procedures specified in Sec.  63.9(k).
* * * * *
    (c) * * *
    (1) At all times, you must maintain and operate any affected 
source,

[[Page 41718]]

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 a 
source is operating in compliance with operation and maintenance 
requirements will be based on information available to the permitting 
authority 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 source.
* * * * *
    (5) Before November 12, 2024, as an alternative to the requirements 
in paragraph (c)(4) of this section, you must comply with the startup, 
shutdown, and malfunction requirements in Sec.  63.6(e)(3). On or after 
November 12, 2024, you may not use the requirements in Sec.  63.6(e)(3) 
as an alternative to the requirements in paragraph (c)(4) of this 
section. You must comply with all emissions limitation or work practice 
standards in this subpart at all times.
    (d) Deviations. You must submit written notification to the 
permitting authority of any deviation from the requirements of this 
subpart, including the number, date, time, duration, and the cause of 
such events (including unknown cause, if applicable); 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; and the probable cause of 
such deviations and any corrective actions or preventative measures 
taken. You must submit this notification within 14 days of the date the 
deviation started.
    (e) Reports. (1) You must submit semiannual monitoring reports to 
your permitting authority. All instances of deviations from the 
requirements of this subpart must be clearly identified in the reports. 
The report must contain the number, date, time, duration, and the cause 
of each deviation (including unknown cause, if applicable); 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; and the probable cause of 
such deviations and any corrective actions or preventative measures 
taken. Examples of methods used to estimate the emissions would include 
product-loss calculations, mass balance calculations, measurements when 
available, or engineering judgment based on known process parameters.
    (2) Beginning November 13, 2024, the owner or operator must 
electronically submit all subsequent semiannual monitoring reports in 
PDF format to the EPA via CEDRI, which can be accessed through EPA's 
CDX (https://cdx.epa.gov/) following the procedures specified in Sec.  
63.9(k).
* * * * *

0
6. Amend Sec.  63.11148 by:
0
a. Revising paragraphs (a)(1), (a)(3)(ii), (a)(4)(iv), (b)(1), 
(b)(2)(i), (b)(4), (c)(2) and (4), (e)(3), (f)(1), (f)(4)(ii) and 
(iii), (f)(5), (g), and (h); and
0
b. Adding paragraph (i).
    The revisions and addition read as follows:


Sec.  63.11148  What are the standards and compliance requirements for 
existing sources using batch copper converters?

    (a) * * *
    (1) For each copper concentrate dryer, you must not discharge to 
the atmosphere from the dryer vent any gases that contain filterable 
particulate matter (PM) in excess of 0.022 grains per dry standard 
cubic foot (gr/dscf).
* * * * *
    (3) * * *
    (ii) You must not cause to be discharged to the atmosphere from the 
capture system used to comply with paragraph (a)(3)(i) of this section 
any gases that contain filterable PM in excess of 0.022 gr/dscf.
    (4) * * *
    (iv) For each secondary capture system that is used to comply with 
paragraph (a)(4)(ii) of this section and is not vented to a gas 
cleaning system controlling PM and a sulfuric acid plant, you must not 
cause to be discharged to the atmosphere any gases that contain 
filterable particulate matter in excess of 0.02 grains/dscf.
    (b) * * *
    (1) Each COMS must meet Performance Specification 1 in appendix B 
to 40 CFR part 60.
    (2) * * *
    (i) You must automatically (intrinsic to the opacity monitor) check 
the zero and upscale (span) calibration drifts at least once daily. For 
a particular COMS, the acceptable range of zero and upscale calibration 
materials is as defined in the applicable version of Performance 
Specification 1 in appendix B to 40 CFR part 60.
* * * * *
    (4) You must log in ink or electronic format and maintain a record 
of 24-hour opacity measurements performed in accordance with paragraph 
(b)(3) of this section and any corrective actions taken, if any. A 
record of corrective actions taken must include the start date, start 
time, and duration in hours during which the 24-hour rolling average 
opacity exceeded 15 percent and the start date, start time and type of 
the corrective action and the date and time the corrective action was 
completed.
    (c) * * *
    (2) The baghouse leak detection system must meet the specifications 
and requirements in paragraphs (c)(2)(i) through (vi) of this section.
    (i) The bag leak detection system must be certified by the 
manufacturer to be capable of detecting particulate matter emissions at 
concentrations that can effectively discern any dysfunctional leaks of 
the baghouse.
    (ii) The bag leak detection system sensor must provide output of 
relative or absolute particulate matter loadings.
    (iii) The bag leak detection system must be equipped with a device 
to continuously record the output signal from the sensor.
    (iv) The bag leak detection system must be equipped with an alarm 
system that will sound automatically when an increase in relative 
particulate emissions over a preset level is detected. The alarm must 
be located where it is easily heard by plant operating personnel.
    (v) The bag leak detection system must be installed downstream of 
the baghouse.
    (vi) The bag leak detection system must be installed, operated, 
calibrated, and maintained in a manner consistent with the 
manufacturer's written specifications and recommendations. The 
calibration of the system must, at a minimum, consist of establishing 
the relative baseline output level by adjusting the sensitivity and the 
averaging period of the device and establishing the alarm set points 
and the alarm delay time.
* * * * *
    (4) You must log in ink or electronic format and maintain a record 
of installation, calibration, maintenance, and operation of the bag 
leak detection system. If the bag leak detection system alarm sounds, 
the records must include an identification of the date and time of all 
bag leak detection alarms, their cause, the time you initiated 
corrective actions, and an explanation of the corrective actions taken, 
including the date corrective actions were completed, if any.
* * * * *
    (e) * * *

[[Page 41719]]

    (3) Before November 12, 2024, you must conduct each performance 
test according to Sec.  63.7(e)(1) using the test methods and 
procedures in paragraphs (e)(3)(i) through (v) of this section. On or 
after November 12, 2024, you must conduct each performance test using 
the test methods and procedures in paragraphs (e)(3)(i) through (vi) of 
this section.
    (i) Method 1 or 1A in appendix A-1 to 40 CFR part 60 to select 
sampling port locations and the number of traverse points in each stack 
or duct. Sampling sites must be located at the outlet of the control 
device (or at the outlet of the emissions source if no control device 
is present) prior to any releases to the atmosphere.
    (ii) Method 2, 2A, 2C, 2D, 2F, or 2G in appendices A-1 and A-2 to 
40 CFR part 60 to determine the volumetric flow rate of the stack gas.
    (iii) Method 3, 3A, or 3B in appendix A-2 to 40 CFR part 60 to 
determine the dry molecular weight of the stack gas. You may use ANSI/
ASME PTC 19.10-1981 (incorporated by reference--see Sec.  63.14) as an 
alternative to EPA Method 3B manual portion only and not the 
instrumental portion.
    (iv) Method 4 in appendix A-3 to 40 CFR part 60 to determine the 
moisture content of the stack gas.
    (v) Method 5 in appendix A-3 to 40 CFR part 60 to determine the PM 
concentration for negative pressure baghouses or Method 5D in appendix 
A-3 to 40 CFR part 60 for positive pressure baghouses. A minimum of 
three valid test runs are needed to comprise a PM performance test.
    (vi) You must conduct each performance test that applies to your 
affected source under normal operating conditions of the affected 
source. The owner or operator may not conduct performance tests during 
periods of malfunction. The owner or operator 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 shall make 
available to the Administrator such records as may be necessary to 
determine the conditions of performance tests.
    (f) * * *
    (1) At all times, you must maintain and operate any affected 
source, 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 a 
source is operating in compliance with operation and maintenance 
requirements will be based on information available to the permitting 
authority 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 source.
* * * * *
    (4) * * *
    (ii) You must document through signed contemporaneous logs or other 
relevant evidence that an emergency occurred, and you can identify the 
probable cause, your facility was being operated properly at the time 
the emergency occurred, and the corrective actions taken to minimize 
emissions as required by paragraph (f)(4)(i) of this section. 
Documentation must include the date, time, duration, of such events 
(including unknown cause, if applicable); a list of the affected 
sources or equipment; and 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.
    (iii) You must submit a notice of the emergency to the permitting 
authority within two working days of the time when emission limitations 
were exceeded due to the emergency (or an alternate timeframe 
acceptable to the permitting authority). This notice must contain the 
number, date, time, duration, and the cause of such events (including 
unknown cause, if applicable); 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; and the probable cause of such deviations and 
any corrective actions or preventative measures taken.
    (5) Before November 12, 2024, as an alternative to the requirements 
in paragraph (f)(4) of this section, you must comply with the startup, 
shutdown, and malfunction requirements in Sec.  63.6(e)(3). On or after 
November 12, 2024, you may not use the requirements in Sec.  63.6(e)(3) 
as an alternative to the requirements in paragraph (f)(4) of this 
section. Emissions limitation or work practice standards in this 
subpart apply at all times.
    (g) Recordkeeping requirements. (1) You must maintain records of 
the occurrence and duration in hours of each startup, shutdown, or 
malfunction of process, air pollution control, and monitoring 
equipment.
    (2) In the event that an affected unit fails to meet an applicable 
standard, record the number of failures. For each failure record the 
date, time, cause and duration of each failure.
    (3) For each failure to meet an applicable standard, record and 
retain a list of the affected sources or equipment, whether the failure 
occurred during a period of startup, shutdown or malfunction, actions 
taken to minimize emissions, 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.
    (4) Record actions taken to minimize emissions in accordance with 
Sec.  63.11147(c), paragraph (f) of this section, or Sec.  
63.11149(c)(3) as applicable, and any corrective actions taken to 
return the affected unit to its normal or usual manner of operation.
    (5) You must maintain a file of all measurements, including 
continuous monitoring system, monitoring device, and performance 
testing measurements; all continuous monitoring system performance 
evaluations; all continuous monitoring system or monitoring device 
calibration checks; adjustments and maintenance performed on these 
systems or devices; and all other information required by this section 
recorded in a permanent form suitable for inspection. The file must be 
retained for at least 5 years following the date of such measurements, 
maintenance, and reports.
    (6) Any records required to be maintained by this subpart that are 
submitted electronically via the EPA's CEDRI may be maintained in 
electronic format. This ability to maintain electronic copies does not 
affect the requirement for facilities to make records, data, and 
reports available upon request to a delegated air agency or the EPA as 
part of an on-site compliance evaluation.
    (h) Reporting requirements. (1) You must prepare and submit to the 
permitting authority an excess emissions and monitoring systems 
performance report and summary report every calendar quarter. A less 
frequent reporting interval may be used for either report as approved 
by the permitting authority.
    (2) The summary report must include the information in paragraphs 
(h)(2)(i) through (iv) of this section.

[[Page 41720]]

    (i) The magnitude of excess emissions computed, any conversion 
factor(s) used, and the date and time of commencement and completion of 
each time period of excess emissions. The process operating time during 
the reporting period. Examples of methods used to estimate the 
emissions would include product-loss calculations, mass balance 
calculations, measurements when available, or engineering judgment 
based on known process parameters.
    (ii) Specific identification of each period of excess emissions 
that occurs during startups, shutdowns, and malfunctions of the 
affected facility. The nature and cause of any malfunction (if known), 
the corrective action taken or preventative measures adopted.
    (iii) The date, time, and duration in hours identifying each period 
during which the continuous monitoring system was inoperative except 
for zero and span checks and the nature of the system repairs or 
adjustments.
    (iv) When no excess emissions have occurred or the continuous 
monitoring system(s) have not been inoperative, repaired, or adjusted, 
such information must be stated in the report.
    (i) Electronic reporting requirements. Beginning on November 13, 
2024, 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 procedures specified in Sec.  63.9(k).
    (1) Data collected using test methods supported by the EPA's 
Electronic Reporting Tool (ERT) as listed on the EPA's ERT website 
(https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert) at the time of the test. Submit the results of the 
performance test to the EPA via the Compliance and Emissions Data 
Reporting Interface (CEDRI), which can be accessed through the EPA's 
Central Data Exchange (CDX) (https://cdx.epa.gov/). The data must be 
submitted in a file format generated using the EPA's ERT. 
Alternatively, you may submit an electronic file consistent with the 
extensible markup language (XML) schema listed on the EPA's ERT 
website.
    (2) Data collected using test methods that are not supported by the 
EPA's ERT as listed on the EPA's ERT website at the time of the test. 
The results of the performance test must be included as an attachment 
in the ERT or an alternate electronic file consistent with the XML 
schema listed on the EPA's ERT website. Submit the ERT generated 
package or alternative file to the EPA via CEDRI.

0
7. Revise Sec.  63.11149 to read as follows:


Sec.  63.11149  What are the standards and compliance requirements for 
new sources?

    (a) Emissions limits and work practice standards. (1) You must not 
discharge to the atmosphere exhaust gases that contain filterable PM in 
excess of 0.6 pound per ton of copper concentrate feed charged on a 24-
hour average basis from any combination of stacks, vents, or other 
openings on furnaces, reactors, or other types of process vessels used 
for the production of anode copper from copper sulfide ore concentrates 
by pyrometallurgical techniques. Examples of such process equipment 
include, but are not limited to, copper concentrate dryers, smelting 
flash furnaces, smelting bath furnaces, converting vessels, combined 
smelting and converting reactors, anode refining furnaces, and anode 
shaft furnaces.
    (2) You must operate a capture system that collects the gases and 
fumes released during the transfer of molten materials from smelting 
vessels and converting vessels and conveys the collected gas stream to 
a baghouse or other PM control device.
    (3) You must operate one or more capture systems that collect the 
gases and fumes released from each vessel used to refine blister 
copper, remelt anode copper, or remelt anode scrap and convey each 
collected gas stream to a baghouse or other PM control device. One 
control device may be used for multiple collected gas streams.
    (b) Monitoring requirements. (1) You must install, operate, and 
maintain a PM continuous emissions monitoring system (CEMS) to measure 
and record PM concentrations and gas stream flow rates for the exhaust 
gases discharged to the atmosphere from each affected source subject to 
the emissions limit in paragraph (a)(1) of this section. A single PM 
CEMS may be used for the combined exhaust gas streams from multiple 
affected sources at a point before the gases are discharged to the 
atmosphere. For each PM CEMS used to comply with this paragraph (b)(1), 
you must meet the requirements in paragraphs (b)(1)(i) through (iii) of 
this section.
    (i) You must install, certify, operate, and maintain the PM CEMS 
according to EPA Performance Specification 11 in appendix B to 40 CFR 
part 60, and the quality assurance requirements of Procedure 2 in 
appendix F to 40 CFR part 60.
    (ii) You must conduct an initial performance evaluation of the PM 
CEMS according to the requirements of Performance Specification 11 in 
appendix B to 40 CFR part 60. Thereafter, you must perform the 
performance evaluations as required by Procedure 2 in appendix F to 40 
CFR part 60.
    (iii) You must perform quarterly accuracy determinations and daily 
calibration drift tests for the PM CEMS according to Procedure 2 in 
appendix F to 40 CFR part 60.
    (2) You must install, operate, and maintain a weight measurement 
system to measure and record the weight of the copper concentrate feed 
charged to the smelting vessel on a daily basis.
    (3)(i) You must comply with the requirements in Sec.  63.8(d)(1) 
and (2).
    (ii) The owner or operator shall keep the written procedures 
required in Sec.  63.8(d)(1) and (2) on record for the life of the 
affected source or until the affected source is no longer subject to 
the provisions of this part, to be made available for inspection, upon 
request, by the Administrator. If the performance evaluation plan is 
revised, the owner or operator shall keep previous (i.e., superseded) 
versions of the performance evaluation plan on record to be made 
available for inspection, upon request, by the Administrator, for a 
period of 5 years after each revision to the plan. The program of 
corrective action should be included in the plan required under Sec.  
63.8(d)(2).
    (c) Compliance requirements. (1) You must demonstrate initial 
compliance with the emissions limit in paragraph (a)(1) of this section 
using the procedures in paragraph (c)(2) this section within 180 days 
after startup and report the results in your notification of compliance 
status no later than 30 days after the end of the compliance 
demonstration.
    (2) You must demonstrate continuous compliance with the emissions 
limit in paragraph (a)(1) of this section using the procedures in 
paragraphs (c)(2)(i) through (iii) of this section whenever your 
facility is producing copper from copper concentrate.
    (i) You must continuously monitor and record PM emissions, 
determine and record the daily (24-hour) value for each day, and 
calculate and record the daily average pounds of filterable PM per ton 
of copper concentrate feed charged to the smelting vessel according to 
the requirements in paragraph (b) of this section.
    (ii) You must calculate the daily average at the end of each 
calendar day for the preceding 24-hour period.
    (iii) You must maintain records of the calculations of daily 
averages with supporting information and data, including measurements 
of the weight of copper concentrate feed charged to

[[Page 41721]]

the smelting vessel. Collected PM CEMS data must be made available for 
inspection.
    (3)(i) At all times, you must maintain and operate any affected 
source, 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 a 
source is operating in compliance with operation and maintenance 
requirements will be based on information available to the permitting 
authority 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 source.
    (ii) All pollution control equipment must be installed, maintained, 
and operated properly. Instructions from the vendor or established 
maintenance practices that maximize pollution control must be followed. 
All necessary equipment control and operating devices, such as pressure 
gauges, amp meters, volt meters, flow rate indicators, temperature 
gauges, continuous emissions monitor, etc., must be installed, operated 
properly and easily accessible to compliance inspectors. A copy of all 
manufacturers' operating instructions for pollution control equipment 
and pollution emitting equipment must be maintained at your facility 
site. These instructions must be available to all employees who operate 
the equipment and must be made available to the permitting authority 
upon request. Maintenance records must be made available to the 
permitting authority upon request.
    (iii) You must document the activities performed to assure proper 
operation and maintenance of the air pollution control equipment and 
monitoring systems or devices. Records of these activities must be 
maintained as required by the permitting authority.
    (4)(i) In the event that an affected unit fails to meet an 
applicable standard, record the number of failures. For each failure 
record the date, time, the cause and duration of each failure.
    (ii) For each failure to meet an applicable standard, record and 
retain 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.
    (iii) Record actions taken in accordance with the general duty 
requirements to minimize emissions in paragraph (c)(3) of this section 
and any corrective actions taken to return the affected unit to its 
normal or usual manner of operation.
    (d) Alternative startup, shutdown, and malfunction requirements. 
Before November 12, 2024, you must comply with the requirements 
specified in this paragraph (d) as an alternative to the requirements 
in Sec.  63.6(e)(3). On or after November 12, 2024, you may not use the 
requirements in Sec.  63.6(e)(3) as an alternative to the requirements 
in this paragraph (d). Emissions limitation or work practice standards 
in this subpart apply at all times. In the event of an emergency 
situation, you must comply with the requirements specified in 
paragraphs (d)(1) through (3) of this section. For the purpose of 
complying with this paragraph (d), an emergency situation is any 
situation arising from sudden and reasonably unforeseeable events 
beyond the control of the facility owner or operator that requires 
immediate corrective action to restore normal operation, and that 
causes the affected source to exceed an applicable emissions limitation 
under this subpart, due to unavoidable increases in emissions 
attributable to the emergency. An emergency must not include 
noncompliance to the extent it is caused by improperly designed 
equipment, lack of preventive maintenance, careless or improper 
operation, or operator error.
    (1) During the period of the emergency, you must implement all 
reasonable steps to minimize levels of emissions that exceeded the 
emission standards or other applicable requirements in this subpart.
    (2) You must document through signed contemporaneous logs or other 
relevant evidence that an emergency occurred and you can identify the 
probable cause, your facility was being operated properly at the time 
the emergency occurred, and the corrective actions taken to minimize 
emissions as required by paragraph (d)(1) of this section.
    (3) You must submit a notice of the emergency to the permitting 
authority within two working days of the time when emissions 
limitations were exceeded due to the emergency (or an alternate 
timeframe acceptable to the permitting authority). This notice must 
contain a description of the emergency, any steps taken to mitigate 
emissions, and corrective actions taken.
    (e) Reports. (1) You must submit to the permitting authority by the 
20th day of each month a summary of the daily average PM per ton of 
copper concentrate feed charged to the smelting vessel for the previous 
month.
    (2) Beginning November 12, 2024, the owner or operator must 
electronically submit all subsequent monthly PM emission reports and 
notification of compliance status in PDF format to the EPA via CEDRI, 
which can be accessed through EPA's CDX (https://cdx.epa.gov/) 
following the procedures specified in Sec.  63.9(k).
    (3) For each deviation from an emission limitation in paragraph 
(a)(1) of this section occurring at an affected source, you must 
include in your semiannual monitoring report the information in 
paragraphs (e)(3)(i) through (x) of this section.
    (i) The date and time that each malfunction started and stopped.
    (ii) The start date, and start time, and duration in hours (or 
minutes for CEMS) that each continuous monitoring system was 
inoperative, except for zero (low-level) and high-level checks.
    (iii) The start date, start time, and duration in hours (or minutes 
for CEMS) that each continuous monitoring system was out-of-control, 
including the information in Sec.  63.8(c)(8).
    (iv) The total duration in hours (or minutes for CEMS) of all 
deviations for each CMS during the reporting period, the total 
operating time in hours of the affected source during the reporting 
period, a summary of the total duration of the deviation during the 
reporting period and the total duration as a percent of the total 
source operating time during that reporting period.
    (v) A breakdown of the total duration in hours (or minutes for 
CEMS) of the deviations during the reporting period including those 
that are due to control equipment problems, process problems, other 
known causes, and other unknown causes.
    (vi) The total duration in hours (or minutes for CEMS) of 
continuous monitoring system downtime for each CMS during the reporting 
period, the total operating time in hours of the affected source during 
the reporting period, and the total duration of CMS downtime as a 
percent of the total source operating time during the reporting period.
    (vii) A brief description of the process units.
    (viii) The monitoring equipment manufacturer and model number and 
the pollutant or parameter monitored.
    (ix) The date of the latest continuous monitoring system 
certification or audit.
    (x) A description of any changes in continuous monitoring systems, 
processes, or controls since the last reporting period.

[[Page 41722]]


0
8. Amend Sec.  63.11151 by adding the definition ``Blowing'' in 
alphabetical order and revising the definition ``Capture system'' to 
read as follows:


Sec.  63.11151  What definitions apply to this subpart?

* * * * *
    Blowing means the operating mode for a batch copper converter 
during which air or oxygen-enriched air is injected into the molten 
converter bath.
    Capture system means the collection of components used to capture 
gases and fumes released from one or more emissions points and then 
convey the captured gas stream to a control device. A capture system 
may include, but is not limited to, the following components as 
applicable to a given capture system design: duct intake devices, 
hoods, enclosures, ductwork, dampers, manifolds, plenums, and fans.
* * * * *

0
9. Amend Sec.  63.11152 by:
0
a. Revising paragraph (c) introductory text;
0
b. Removing the undesignated paragraph after paragraph (c)(5); and
0
c. Adding paragraph (c)(6).
    The revision and addition read as follows:


Sec.  63.11152  Who implements and enforces this subpart?

* * * * *
    (c) The authorities that will not be delegated to State, local, or 
tribal agencies are listed in paragraphs (c)(1) through (6) of this 
section.
* * * * *
    (6) Approval of an alternative to any electronic reporting to the 
EPA required by this subpart.

0
10. Revise table 1 to subpart EEEEEE of part 63 to read as follows:

Table 1 to Subpart EEEEEE of Part 63--Applicability of General 
Provisions to This Subpart

    As required in Sec.  63.11150(a), you must comply with the 
requirements of the NESHAP General Provisions (subpart A of this part) 
as shown in the following table.

----------------------------------------------------------------------------------------------------------------
                                                                    Applies to this
               Citation                        Subject                  subpart?               Explanation
----------------------------------------------------------------------------------------------------------------
Sec.   63.1(a)(1) through (4), (6),    Applicability..........  Yes....................
 and (10) through (12), (b)(1) and
 (3), (c)(1), (2), and (5), (e).
Sec.   63.1(a)(5) and (7) through      Reserved...............  No.....................
 (9), (b)(2), (c)(3) and (4), (d).
Sec.   63.2..........................  Definitions............  Yes....................
Sec.   63.3..........................  Units and Abbreviations  Yes....................
Sec.   63.4..........................  Prohibited Activities    Yes....................
                                        and Circumvention.
Sec.   63.5..........................  Preconstruction Review   No.....................
                                        and Notification
                                        Requirements.
Sec.   63.6(a), (b)(1) through (5)     Compliance with          Yes....................
 and (7), (c)(1), (2), and (5).         Standards and
                                        Maintenance
                                        Requirements--Applicab
                                        ility and Compliance
                                        Dates.
Sec.   63.6(e)(1)(i).................  Operation and            Yes before November 12,  See Sec.  Sec.
                                        Maintenance              2024.                    63.11147(c) and
                                        Requirements--general   No on or after November   63.11148(f) for the
                                        duty to minimize         12, 2024.                general duty to
                                        emissions.                                        minimize emissions at
                                                                                          all times at existing
                                                                                          sources. See Sec.
                                                                                          63.11149(c)(3) for the
                                                                                          general duty to
                                                                                          minimize emissions at
                                                                                          all times at new
                                                                                          sources.
Sec.   63.6(e)(1)(ii)................  Requirement to correct   Yes before November 12,  Malfunctions are no
                                        malfunctions as soon     2024.                    longer exempt.
                                        as practicable..        No on or after November
                                                                 12, 2024.
Sec.   63.6(e)(1)(iii)...............  .......................  Yes....................
Sec.   63.6(e)(3)....................  Startup, Shutdown, and   Yes before November 12,  The requirements for
                                        Manufacturing Plan.      2024.                    emergency situations
                                                                No on or after November   for existing sources
                                                                 12, 2024.                are contained in Sec.
                                                                                          Sec.   63.11147(c)(5)
                                                                                          and 63.11148(f)(5).
                                                                                          See Sec.   63.11149(d)
                                                                                          for the emergency
                                                                                          requirements for new
                                                                                          sources.
Sec.   63.6(f)(1)....................  Compliance with          Yes before November 12,  Emission standards
                                        Nonopacity Emission      2024.                    apply at all times.
                                        Standards.              No on or after November   Some requirements of
                                                                 12, 2024.                Sec.   63.6(f)(1) are
                                                                                          no longer applicable.
Sec.   63.6(f)(2) through (3)........  .......................  Yes....................
Sec.   63.6(g), (i), (j).............  Compliance with          Yes....................
                                        Nonopacity Emission
                                        Standards.
Sec.   63.6(h)(1)....................  Compliance with Opacity  Yes before November 12,  Requirements apply to
                                        and Visible Emission     2024.                    new sources but not
                                        Standards.              No on or after November   existing sources.
                                                                 12, 2024.                Emission standards
                                                                                          apply at all times.
                                                                                          Some requirements of
                                                                                          Sec.   63.6(h)(1) are
                                                                                          no longer applicable.
Sec.   63.6(b)(6), (c)(3) and (4),     Reserved...............  No.....................
 (d), (e)(2), (e)(3)(ii), (h)(2)(ii),
 (h)(3), (h)(5)(iv), (i)(15).

[[Page 41723]]

 
Sec.   63.6(h)(2) through (4),         .......................  Yes/No.................  Requirements apply to
 (h)(5)(i) through (iii), (h)(6)                                                          new sources but not
 through (9).                                                                             existing sources.
Sec.   63.7(a), (e)(2) through (4),    Performance Testing      Yes....................
 (f), (g), (h).                         Requirements.
Sec.   63.7(e)(1)....................  Performance Testing      No.....................  See Sec.   63.11148(e)
                                        Requirements.                                     for performance
                                                                                          testing requirements.
Sec.   63.7(b), (c)..................  .......................  Yes/No.................  Notification of
                                                                                          performance tests and
                                                                                          quality assurance
                                                                                          program apply to new
                                                                                          sources but not
                                                                                          existing sources.
Sec.   63.8(a)(1) and (2), (b),        Monitoring Requirements  Yes....................
 (c)(1)(ii), (c)(2) through (8), (f),
 (g).
Sec.   63.8(c)(1)(i) and (iii).......  General Duty and SSM     Yes before November 12,
                                        Plan Requirements for    2024..
                                        Continuous Monitoring   No on or after November
                                        Systems.                 12, 2024..
Sec.   63.8(a)(3)....................  Reserved...............  No.....................
Sec.   63.8(a)(4)....................  .......................  No.....................  This subpart does not
                                                                                          require flares.
Sec.   63.8(d)(1) and (2), (e).......  Quality Control........  Yes/No.................  Requirements for
                                                                                          quality control
                                                                                          program and
                                                                                          performance
                                                                                          evaluations apply to
                                                                                          new sources but not
                                                                                          existing sources.
Sec.   63.8(d)(3)....................  Written Procedures for   Yes before November 12,  Requirements for
                                        Continuous Monitoring    2024.                    quality control
                                        Systems.                No on or after November   program and
                                                                 12, 2024.                performance
                                                                                          evaluations apply to
                                                                                          new sources but not
                                                                                          existing sources. See
                                                                                          Sec.   63.11149(b)(3).
Sec.   63.9(a), (b)(1), (2), and (5),  Notification             Yes....................
 (c), (d), (h)(1) through (3), (5),     Requirements.
 and (6), (i), (j).
Sec.   63.9(b)(3), (h)(4)............  Reserved...............  No.....................
Sec.   63.9(b)(4), (f)...............  .......................  No.....................
Sec.   63.9(e), (g)..................  .......................  Yes/No.................  Notification
                                                                                          requirements for
                                                                                          performance test and
                                                                                          use of continuous
                                                                                          monitoring systems
                                                                                          apply to new sources
                                                                                          but not existing
                                                                                          sources.
Sec.   63.9(k).......................  Electronic submission    Yes....................
                                        of notifications or
                                        reports.
Sec.   63.10(a), (b)(1), (d)(1), (2),  Recordkeeping and        Yes/No.................  Recordkeeping
 and (4), (f).                          Reporting Requirements.                           requirements apply to
                                                                                          new sources but not
                                                                                          existing sources.
Sec.   63.10(b)(2)(iii) and (vi)       .......................  Yes/No.................  Recordkeeping
 through (xiv), (b)(3), (c)(1), (5)                                                       requirements apply to
 through (8), and (10) through (14),                                                      new sources but not
 (e)(1) and (2).                                                                          existing sources.
Sec.   63.10(b)(2)(i) through (ii)     General Recordkeeping    Yes before November 12,  Recordkeeping
 and (iv) through (v).                  Requirements and         2024.                    requirements apply to
                                        Actions to Minimize     No on or after November   new sources but not
                                        Emissions During         12, 2024.                existing sources. See
                                        Startup, Shutdown, and                            Sec.   63.11149(c)(4).
                                        Malfunction.                                     Startup, Shutdown, and
                                                                                          Malfunction are no
                                                                                          longer exempt from
                                                                                          emission standards.
                                                                                          See Sec.
                                                                                          63.11148(g).
Sec.   63.10(c)(2) and (4) and (9)...  Reserved...............  No.....................
Sec.   63.10(c)(15)..................  Use of Startup,          For new sources, Yes     Recordkeeping
                                        Shutdown, and            before November 12,      requirements apply to
                                        Malfunction Plan.        2024.                    new sources but not
                                                                No on or after November   existing sources.
                                                                 12, 2024.               Startup, Shutdown, and
                                                                                          Malfunction Plans are
                                                                                          no longer required.
Sec.   63.10(d)(3), (e)(4)...........  .......................  No.....................  Reporting requirements
                                                                                          apply to new sources
                                                                                          but not existing
                                                                                          sources.
Sec.   63.10(d)(5)...................  Startup, Shutdown, and   For new sources, Yes     Reporting requirements
                                        Malfunction Reporting.   before November 12,      apply to new sources
                                                                 2024.                    but not existing
                                                                No on or after November   sources. See Sec.
                                                                 12, 2024.                Sec.   63.11147(e),
                                                                                          63.11148(h),
                                                                                          63.11149(e)(2).
Sec.   63.10(e)(3)...................  .......................  Yes/No.................  Reporting requirements
                                                                                          apply to new sources
                                                                                          but not existing
                                                                                          sources.
Sec.   63.11.........................  Control Device           No.....................  This subpart does not
                                        Requirements.                                     require flares.

[[Page 41724]]

 
Sec.   63.12.........................  State Authorities and    Yes....................
                                        Delegations.
Sec.   63.13.........................  Addresses..............  Yes....................
Sec.   63.14.........................  Incorporations by        Yes....................
                                        Reference.
Sec.   63.15.........................  Availability of          Yes....................
                                        Information and
                                        Confidentiality.
Sec.   63.16.........................  Performance Track        Yes....................
                                        Provisions.
----------------------------------------------------------------------------------------------------------------

[FR Doc. 2024-09883 Filed 5-10-24; 8:45 am]
 BILLING CODE 6560-50-P