[Federal Register Volume 89, Number 45 (Wednesday, March 6, 2024)]
[Rules and Regulations]
[Pages 16408-16441]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-02305]



[[Page 16407]]

Vol. 89

Wednesday,

No. 45

March 6, 2024

Part IV





Environmental Protection Agency





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40 CFR Part 63





National Emission Standards for Hazardous Air Pollutants: Taconite Iron 
Ore Processing; Final Rule

Federal Register / Vol. 89 , No. 45 / Wednesday, March 6, 2024 / 
Rules and Regulations

[[Page 16408]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2017-0664; FRL-5925.1-01-OAR]
RIN 2060-AV58


National Emission Standards for Hazardous Air Pollutants: 
Taconite Iron Ore Processing

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The U.S. Environmental Protection Agency (EPA) is finalizing 
amendments to the National Emission Standards for Hazardous Air 
Pollutants (NESHAP) for Taconite Iron Ore Processing. Specifically, the 
EPA is finalizing maximum achievable control technology (MACT) 
standards for mercury (Hg) and establishing revised emission standards 
for hydrogen chloride (HCl) and hydrogen fluoride (HF). This final 
action ensures that emissions of all hazardous air pollutants (HAP) 
emitted from the Taconite Iron Ore Processing source category are 
regulated.

DATES: This final rule is effective March 6, 2024. The incorporation by 
reference (IBR) of certain publications listed in the rule is approved 
by the Director of the Federal Register (FR) as of March 6, 2024. The 
incorporation by reference of certain other material listed in the rule 
was approved by the Director of the Federal Register as of October 26, 
2020.

ADDRESSES: The EPA established a docket for this action under Docket ID 
No. EPA-HQ-OAR-2017-0664. 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 
(CBI) or other information whose disclosure is restricted by statute. 
Certain other material, such as copyrighted material, is not placed on 
the internet and is publicly available only in hard copy. With the 
exception of such material, publicly available docket materials are 
available electronically in https://www.regulations.gov/or in hard copy 
at the EPA Docket Center, Room 3334, WJC West Building, 1301 
Constitution Avenue NW, Washington, DC. The Public Reading Room is open 
from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal 
holidays. 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 David Putney, Sector Policies and Programs Division (D243-02), 
Office of Air Quality Planning and Standards, U.S. Environmental 
Protection Agency, 109 T.W. Alexander Drive, P.O. Box 12055, Research 
Triangle Park, North Carolina, 27711; telephone number: (919) 541-2016; 
email address: <a href="/cdn-cgi/l/email-protection#a5d5d0d1cbc0dc8bc1c4d3ccc1e5c0d5c48bc2cad3"><span class="__cf_email__" data-cfemail="b1c1c4c5dfd4c89fd5d0c7d8d5f1d4c1d09fd6dec7">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION: 
    Preamble acronyms and abbreviations. Throughout this document the 
use of ``we,'' ``us,'' or ``our'' is intended to refer to the EPA. We 
use multiple acronyms and terms in this preamble. While this list may 
not be exhaustive, to ease the reading of this preamble and for 
reference purposes, the EPA defines the following terms and acronyms 
here:

ACI activated carbon injection
BTF beyond-the-floor
CAA Clean Air Act
CBI Confidential Business Information
CEMS continuous emission monitoring system
CFR Code of Federal Regulations
D.C. Circuit United States Court of Appeals for the District of 
Columbia Circuit
DSI dry sorbent injection
EJ environmental justice
EPA Environmental Protection Agency
ESP electrostatic precipitator
FR Federal Register
HAP hazardous air pollutant(s)
HCl hydrochloric acid
HF hydrogen fluoride
Hg mercury
ICR information collection request
km kilometer
LEAN Louisiana Environmental Action Network
lb/LT pounds of HAP (i.e., Hg, HCl, or HF) emitted per long ton of 
pellets produced
MACT maximum achievable control technology
MWh/yr megawatt-hours per year
MPCA Minnesota Pollution Control Agency
NAICS North American Industry Classification System
NESHAP National Emission Standards for Hazardous Air Pollutants
ng/g nanograms per gram
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management and Budget
PM particulate matter
PRA Paperwork Reduction Act
RFA Regulatory Flexibility Act
RTR residual risk and technology review
tpy tons per year
UPL upper prediction limit
[mu]g/Nm3 microgram per normal cubic meter
UMRA Unfunded Mandates Reform Act
VCS voluntary consensus standards

    Organization of this document. The information in this preamble is 
organized as follows:

I. General Information
    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related 
information?
    C. Judicial Review and Administrative Reconsideration
II. Background
    A. What is the statutory authority for this action?
    B. What is the source category and how does the current NESHAP 
regulate its HAP emissions?
    C. What changes did we propose for the Taconite Iron Ore 
Processing source category?
III. What is the rationale for our final decisions and amendments 
for the Taconite Iron Ore Processing source category?
    A. MACT Standards for Mercury
    B. Revised Emission Standards for HCl and HF
    C. What other amendments are we finalizing?
    D. What are the effective and compliance dates for the mercury, 
HCl, and HF emission standards?
IV. Summary of Cost, Environmental, and Economical Impacts
    A. What are the affected sources?
    B. What are the air quality impacts?
    C. What are the cost impacts?
    D. What are the economic impacts?
    E. What analysis of environmental justice did we conduct?
V. Statutory and Executive Order Reviews
    A. Executive Order 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. National Technology Transfer and Advancement Act (NTTAA) and 
1 CFR Part 51
    H. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations and Executive Order 14096: Revitalizing Our Nation's 
Commitment to Environmental Justice for All
    I. Executive Order 13045: Protection of Children From 
Environmental Health Risks and Safety Risks
    J. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    K. Congressional Review Act (CRA)

I. General Information

A. Does this action apply to me?

    Table 1 of this preamble lists the NESHAP and associated regulated 
industrial source category that is the

[[Page 16409]]

subject of this final rule. Table 1 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 are directly 
applicable to the affected sources. Federal, state, local, and Tribal 
government entities are not 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 Taconite Iron Ore 
Processing source category includes any facility engaged in separating 
and concentrating iron ore from taconite, a low-grade iron ore to 
produce taconite pellets. The source category includes, but is not 
limited to, the following processes: liberation of the iron ore by wet 
or dry crushing and grinding in gyratory crushers, cone crushers, rod 
mills, and ball mills; pelletizing by wet tumbling with a balling drum 
or balling disc; induration using a straight grate or grate kiln 
indurating furnace; and finished pellet handling.

   Table 1--NESHAP and Source Categories Affected by This Final Action
------------------------------------------------------------------------
          Source category                  NESHAP         NAICS code \1\
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Taconite Iron Ore Processing......  40 CFR part 63,                21221
                                     subpart RRRRR.
------------------------------------------------------------------------
\1\ North American Industry Classification System.

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

    In addition to being available in the docket, an electronic copy of 
this action is available on the internet. 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/taconite-iron-ore-processing-national-emission-standards-hazardous. Following publication 
in the Federal Register, the EPA will post the Federal Register version 
of the final rule and key technical documents at this same website.

C. 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 
(D.C. Circuit) by May 6, 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 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?

    In the Louisiana Environmental Action Network v. EPA (``LEAN'') 
decision issued on April 21, 2020, the D.C. Circuit held that the EPA 
has an obligation to address regulatory gaps, such as missing standards 
for HAP known to be emitted from a major source category, when the 
Agency conducts the 8-year technology review required by CAA section 
112(d)(6).\1\ Emissions data collected from the exhaust stacks of 
existing taconite indurating furnaces indicate that Hg is emitted from 
the source category. However, Hg emissions from the Taconite Iron Ore 
Processing source category are not regulated under the existing 
Taconite Iron Ore Processing NESHAP. To meet the EPA's obligations 
under CAA section 112(d)(6), in this action, the EPA is establishing 
new standards for Hg emissions from the Taconite Iron Ore Processing 
source category that reflect MACT for Hg emitted from taconite 
indurating furnaces, pursuant to CAA sections 112(d)(2) and (3).
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    \1\ Louisiana Environmental Action Network v. EPA, 955 F.3d 1088 
(D.C. Cir. 2020) (``LEAN'').
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    The EPA is also finalizing revised standards for HCl and HF 
pursuant to CAA section 112(d)(6). CAA section 112(d)(6) requires the 
EPA to review standards promulgated under CAA section 112 and revise 
them ``as necessary (taking into account developments in practices, 
processes, and control technologies)'' no less often than every 8 
years.

B. What is the source category and how does the current NESHAP regulate 
its HAP emissions?

    The Taconite Iron Ore Processing NESHAP (codified at 40 Code of 
Federal Regulations (CFR) part 63, subpart RRRRR) applies to each new 
or existing ore crushing and handling operation, ore dryer, pellet 
indurating furnace, and finished pellet handling operation at a 
taconite iron ore processing plant that is (or is part of) a major 
source of HAP emissions. Taconite iron ore processing plants separate 
and concentrate iron ore from taconite, a low-grade iron ore containing 
20- to 25-percent iron, and produce taconite pellets, which are 60- to 
65-percent iron. The current NESHAP includes particulate matter (PM) 
limits that, prior to this final action, served as a surrogate for 
particulate metal HAP, HCl, and HF emissions. The existing PM emissions 
limits were summarized in table 2 of the proposal (see 88 FR 30917; May 
15, 2023). The current NESHAP does not presently include standards for 
Hg emissions.
    There are currently eight taconite iron ore processing plants in 
the United States: six plants are located in Minnesota and two are 
located in Michigan. This includes the Empire Mining facility in 
Michigan, which maintains an air quality permit to operate, but has 
been indefinitely idled since 2016 and is therefore not included

[[Page 16410]]

in any analyses (e.g., estimates of emissions or cost impacts) 
associated with this final rulemaking.

C. What changes did we propose for the Taconite Iron Ore Processing 
source category?

    On May 15, 2023, the EPA published a proposal in the Federal 
Register to set MACT standards for Hg emissions from indurating 
furnaces in the source category and to revise the existing emission 
standards for HCl and HF for indurating furnaces. The PM emission 
limits in the current NESHAP will continue to serve as surrogate for 
particulate metal HAP (e.g., nickel and arsenic). The EPA proposed that 
compliance with the emission standards for Hg, HCl, and HF be 
demonstrated through operating limits, monitoring, and performance 
testing. We also proposed minor changes to the electronic reporting 
requirements found in 40 CFR 63.9641(c) and 40 CFR 63.9641(f)(3) to 
reflect new procedures for reporting CBI that included an email address 
for owners and operators to electronically submit compliance reports 
containing CBI to the Office of Air Quality Planning and Standards 
(OAQPS) CBI Office. Finally, we requested comment on our evaluation 
that the addition of 1-bromopropane (1-BP) to the CAA section 112 HAP 
list would not impact the Taconite Iron Ore Processing NESHAP because, 
based on our knowledge of the source category and available emissions 
data, 1-BP is not emitted from this source category.

III. What is the rationale for our final decisions and amendments for 
the Taconite Iron Ore Processing source category?

    For each issue, this section provides a description of what we 
proposed and what we are finalizing, a summary of key comments and 
responses, and the EPA's rationale for the final decisions and 
amendments. For all comments not discussed in this preamble, comment 
summaries and the EPA's responses can be found in the document, Summary 
of Public Comments and Responses for Proposed Amendments to the 
National Emission Standards for Hazardous Air Pollutants for Taconite 
Iron Ore Processing, which is available in the docket for this action.

A. MACT Standards for Mercury

1. What did we propose for the Taconite Iron Ore Processing source 
category?
    As described in the May 15, 2023, proposal (88 FR 30917), we 
proposed MACT standards for Hg for new and existing indurating furnaces 
that reflected the MACT floor level of control, based on the 99-percent 
upper prediction limit (UPL), of 1.4 x 10<SUP>-5</SUP> pounds of Hg 
emitted per long ton of taconite pellets produced (lb/LT) for existing 
sources and 3.1 x 10<SUP>-6</SUP> lb/LT for new sources. We also 
proposed an emissions averaging compliance alternative that would allow 
taconite iron ore processing facilities with more than one existing 
indurating furnace to comply with a Hg emissions limit of 1.26 x 
10<SUP>-5</SUP> lb/LT by averaging emissions on a production-weighted 
basis for two or more existing indurating furnaces located at the same 
facility. In the proposal, we explained that the emissions averaging 
compliance alternative reflected a 10 percent adjustment factor to the 
proposed MACT floor standard and that we expected this 10 percent 
adjustment factor would result in Hg reductions greater than those 
achieved by compliance with the MACT floor on a unit-by-unit basis. We 
proposed that compliance with the Hg MACT standards would be 
demonstrated through initial and periodic performance testing 
(completed at least twice per 5-year permit term), establishing 
operating limits for each control device used to comply with the Hg 
standards, and installing and operating continuous parameter monitoring 
systems (CPMS) to ensure continuous compliance with the Hg standards.
    For the proposal, in addition to calculating the MACT floor, 
pursuant to CAA section 112(d)(2), we also assessed more stringent 
``beyond-the-floor'' (BTF) regulatory options for the Hg MACT 
standards. As discussed in the proposal (88 FR 30923), unlike the MACT 
floor's minimum stringency requirements, the EPA must examine various 
impacts of the more stringent BTF regulatory options in determining 
whether MACT standards are to reflect BTF requirements. These impacts 
include the cost of achieving additional emissions reductions beyond 
those achieved by the MACT floor level of control, any non-air quality 
health and environmental impacts that would result from imposing 
controls BTF, and energy requirements of such BTF measures. If the EPA 
concludes that the more stringent regulatory options have unreasonable 
impacts, the EPA selects the MACT floor level of control as MACT. 
However, if the EPA concludes that impacts associated with BTF levels 
of control are reasonable in light of additional HAP emissions 
reductions achieved, then the EPA selects those BTF levels as MACT.
    We considered BTF regulatory options that were 10, 20, 30, and 40 
percent more stringent than the MACT floor and calculated the capital 
and annual costs as well as secondary impacts associated with each 
option. For a detailed discussion of our analysis of emissions 
reductions and potential secondary impacts developed for the proposal, 
please see the memorandum, Development of Impacts for the Proposed 
Amendments to the NESHAP for Taconite Iron Ore Processing, which is 
available in the docket for this action. We proposed that requiring new 
or existing furnaces to meet BTF emission limits was not reasonable 
based on the estimated capital and operating costs and cost-
effectiveness.
2. What comments did we receive on the proposed Hg MACT standards, and 
what are our responses?
    Comment: Industry commenters provided data that they indicated 
corrected the Hg stack test data submitted in response to the CAA 
section 114 Information Collection Request (ICR) sent to the taconite 
facilities in 2022 for the Tilden, UTAC, Keetac, and Hibbing facilities 
that were used when calculating the baseline emissions, the MACT floor 
standards, and the emission reductions. The commenters indicated that 
the error in the Keetac emissions data resulted in an overestimate of 
both the baseline emissions and the estimated emission reductions that 
could be achieved if the proposed Hg standards were adopted.
    Response: In response to these comments and revised data provided, 
the EPA reviewed the Hg emissions data that we used in the proposal to 
calculate baseline Hg emissions. At proposal we estimated total 
baseline Hg emissions were 1,010 pounds per year. The EPA confirmed 
that errors were present in the Hg emissions data used to calculate the 
baseline emissions. We revised the emissions data as appropriate based 
on the emissions data provided by industry commenters and recalculated 
the baseline emissions, MACT floor emission limits, emission 
reductions, and estimated capital and annual costs accordingly for the 
final rule. The updates to the emissions data did not impact the MACT 
floor limit for existing sources but did decrease the baseline 
emissions and the expected Hg emissions reductions for existing 
sources. The updates to the emissions data changed the Hg standard for 
new sources from 3.1 x 10<SUP>-6</SUP> lb/LT to 2.6 x 10<SUP>-6</SUP> 
lb/LT. The updated baseline Hg emissions for the final rule are 
estimated to be 751 pounds per year (0.38 tons per year (tpy)). We 
estimate

[[Page 16411]]

that unit-by-unit compliance with the final MACT floor limit will 
result in a reduction of 232 pounds of Hg emissions per year and a 
reduction of 247 pounds per year of Hg emissions if all facilities with 
more than one existing taconite furnace elect to demonstrate compliance 
through the emissions averaging compliance alternative. Our analysis is 
presented in detail in the memorandum, Development of Impacts for the 
Final Amendments to the NESHAP for Taconite Iron Ore Processing. The 
updated emissions data used in the revised calculations for the final 
rule are summarized in a separate memorandum, Final Emissions Data 
Collected in 2022 for Indurating Furnaces Located at Taconite Iron Ore 
Processing Plants. These documents are available in the docket for this 
action.
    Comment: One commenter recommended the proposed limit for the 
emissions averaging compliance alternative for existing sources should 
have the same number of significant figures as the MACT floor limit. 
Instead of 1.26 x 10<SUP>-5</SUP> lb/LT, the limit for the emissions 
averaging compliance alternative for existing sources would be rounded 
up to 1.3 x 10<SUP>-5</SUP> lb/LT.
    Response: The EPA agrees with the commenter that the Hg emission 
limit for the emissions averaging compliance option should have only 
two significant figures. The limit cannot have more significant figures 
than Hg MACT floor from which it was derived, which has only two 
significant figures. As recommended by commenters, the Hg emission 
limit in the final rule is revised to 1.3 x 10<SUP>-5</SUP> lb/LT so 
that the limit for the emissions averaging compliance alternative has 
the same number of significant figures as the other Hg limits finalized 
in this rulemaking.
    We estimate that the final Hg emissions averaging compliance 
alternative will reduce Hg emissions by 247 pounds per year, if Hibbing 
and Minntac elect to demonstrate compliance through the emissions 
averaging compliance alternative by each facility installing mercury 
controls on two furnaces and averaging the emissions across all 
furnaces located at their facility. We expect that, should Hibbing and 
Minntac elect to demonstrate compliance through the emissions averaging 
compliance alternative, the Hg reductions would still be greater than 
the reductions we anticipate would be achieved through unit-by-unit 
compliance with the MACT floor level of control. For additional 
details, please refer to section IV.A.1 of the proposal preamble (88 FR 
30925). More information on the final Hg standards, including the 
detailed cost estimates for the Hg emissions averaging compliance 
alternative, may be found in the memorandum, Development of Impacts for 
the Final Amendments to the NESHAP for Taconite Iron Ore Processing, 
which is available in the docket for this action.
    Comment: Commenters recommended that the proposed 40 CFR 
63.9621(d)(4) and 63.9631(j) be revised to allow the mass of taconite 
pellets produced to be determined indirectly through calculation based 
on industry standards. They noted that pellet mass is measured prior to 
offsite shipment and later ``trued-up'' at the end of each month.
    Response: The EPA agrees that taconite pellet production can be 
determined indirectly through calculation using bulk density and volume 
measurements. We have revised the language in 40 CFR 63.9621(d)(4) and 
63.9631(j) to allow the weight of taconite pellets produced to be 
determined either by direct measurement using weigh hoppers, belt weigh 
feeders, or weighed quantities in shipments, or calculated using the 
bulk density and volume measurements.
    Comment: Industry commenters stated that the capital and operating 
costs for Hg controls were underestimated in the proposal and that the 
estimated capital costs were significantly below cost estimates 
developed by industry. The commenters thought the retrofit factor of 
1.2 used by the EPA failed to adequately account for the additional 
costs incurred when retrofitting an existing emission unit with new 
controls. They recommended the EPA use the capital costs prepared by 
industry and apply a retrofit factor of 1.5 or 1.6 with a contingency 
factor of 30 percent to account for the higher costs for retrofit 
projects. The commenters also stated that the total annual costs were 
underestimated because the EPA had underestimated costs for activated 
carbon, electricity, and waste disposal and used an interest rate that 
was too low. Industry commenters also stated that currently, some 
plants recycle iron particles collected by their particulate emission 
control device, but that the presence of activated carbon would create 
product quality issues and make recycling no longer possible. The 
commenters stated the EPA had not accounted for the loss of product and 
increased waste disposal costs in the cost estimates prepared for the 
proposal. The commenters provided cost estimates for the Keetac, 
Minorca, Minntac and UTAC facilities that included estimates of the 
amount of product they assert would be lost if scrubber solids are not 
recycled back through the process and the estimated price for the lost 
product. The commenters also disagreed with the estimated labor costs, 
arguing that both the number of operator hours and hourly labor rates 
were too low.
    Response: For the final rule, the EPA has updated the capital and 
annual costs to reflect the costs in 2023 dollars using an interest 
rate of 8.5 percent and updated unit prices for activated carbon, 
utilities, and labor. The EPA also assessed the commenters concerns 
that ACI would prevent plants from recovering iron particles collected 
with other solids by their particulate emission control device. Based 
on the information provided by industry, ten indurating furnaces 
currently collect the solids from their particulate control devices and 
recycle the solids back to the production process, thereby recovering 
valuable iron product. Commenters said plants using ACI would not be 
able to continue to recover iron in this way because carbon would 
impact the quality of their product. Commenters said EPA should account 
for costs due to the loss of product and increased cost of waste 
disposal of the unrecoverable product. Industry provided estimates of 
the amount of iron that would be lost for the furnaces located at the 
UTAC, Minorca, and Minntac plants. We used this data to estimate iron 
losses for the Hibbing plant and multiplied the estimated iron losses 
for each furnace by the current market price of iron to estimate the 
costs associated with the loss iron product. The updated cost estimates 
that we are using for the final rule, including the basis for the 8.5 
percent interest rate, are documented in the memorandum, Development of 
Impacts for the Final Amendments to the NESHAP for Taconite Iron Ore 
Processing, which is available in the docket for this action.
    The EPA reviewed the capital cost information submitted by industry 
during the comment period and found the information submitted consisted 
of a total capital cost for equipment. However, no breakdown was 
provided from which we could ascertain what was included in the cost 
and little information was provided on how the costs were derived. The 
lack of detail in the cost estimates combined with little supporting 
documentation made it impossible for the EPA to assess the accuracy of 
the cost estimates submitted by industry. Industry commenters indicated 
that the estimated equipment costs for the air pollution control 
equipment for the Minorca and UTAC facilities they submitted were 
estimated using cost data from another project at a different facility 
and scaled using the

[[Page 16412]]

`rule of six-tenths.' The `rule of six-tenths' is a method by which 
equipment costs are estimated as the cost of a known project multiplied 
by a capacity factor raised to the power of six-tenths. The `rule of 
six-tenths' can provide a reasonable order of magnitude estimate of 
equipment costs where the capacities of the two systems are reasonably 
similar. However, the commenters did not identify the facility or 
provide a detailed description of the project to which they are 
applying the rule of six-tenths. Commenters also failed to provide a 
detailed breakdown of the equipment costs used in the `rule of six-
tenths' estimate. Without additional information, the EPA was unable to 
assess the accuracy of the equipment costs provided by commenters. 
Therefore, we are not making any changes based on this information.
    We disagree with the commenters' recommendations that a retrofit 
factor of 1.5 or 1.6 should be applied to the capital costs with a 30-
percent contingency factor. Retrofit factors account for costs directly 
related to the demolition, fabrication, and installation of the control 
system. For the venturi scrubbers we included the 3-percent contingency 
factor and applied a retrofit factor of 1.2 to the estimate of the 
total capital investment for new construction. The EPA's Air Pollution 
Control Cost Manual indicates a 3-percent contingency factor is 
considered appropriate for a mature air pollution control technology 
and states that retrofit costs are ``generally minimal'' for venturi 
scrubbers because of their small footprint.\2\ While we agree with the 
commenters that retrofits may, in some cases, be more expensive than 
new construction, the 1.2 retrofit factor used in the cost estimates 
provides a reasonable increase to account for the higher cost 
associated with retrofit projects that involve replacing an existing 
venturi scrubber with a high-efficiency venturi scrubber, where 
infrastructure (e.g., water and power supply) already exist. The 
retrofit factor applied does not have a significant impact on the total 
annual costs. If a retrofit factor of 1.6 is applied, as recommended by 
the commenters, the total annual costs would increase by about 2 
percent (less than $2 million for replacing the venturi scrubbers on 
all 11 furnaces with mercury emissions currently exceeding the MACT 
floor. We did not apply a retrofit factor to the capital costs for the 
activated carbon injection (ACI) system because the costs were 
estimated using a methodology developed by Sargent & Lundy for the 
EPA's Integrated Planning Model (IPM).\3\ The IPM methodology is based 
on costs for retrofitting ACI on utility boilers and therefore already 
represents the average or typical costs for ACI retrofits.
---------------------------------------------------------------------------

    \2\ EPA's Control Cost Manual provides guidance for the 
development of capital and annual costs for air pollution control 
devices. The Control Cost Manual focuses on point source and 
stationary area source air pollution controls. A copy of the manual 
is available at https://www.epa.gov/economic-and-cost-analysis-air-pollution-regulations/cost-reports-and-guidance-air-pollution.
    \3\ Sargent & Lundy, LLC, IPM Model--Updates to Cost and 
Performance for APC Technologies Mercury Control Cost Development 
Methodology, January 2017. A copy of this document is available at 
https://www.epa.gov/sites/default/files/2018-05/documents/attachment_5-6_hg_control_cost_development_methodology.pdf.
---------------------------------------------------------------------------

    A contingency factor is reserved for costs that could incur a 
reasonable but unanticipated increase but are not directly related to 
the demolition, fabrication, and installation of the system. Retrofit 
and contingency factors can be difficult to assess as they vary based 
on site-specific characteristics. Nevertheless, the EPA considers the 
methodology used to calculate capital and total annual costs to be a 
reasonable approach to estimating costs for the purposes of this 
rulemaking. We note that the EPA may not consider costs in determining 
the MACT floor, and that the cost estimates for the BTF control options 
identified for Hg emissions were determined to be greater than the 
level historically found to be cost-effective for controlling Hg 
emissions.
    Comment: Industry commenters noted that the Hg concentrations in 
taconite ore deposits vary widely both within each mine and between 
mines, which in turn affects Hg emissions. The commenters said the 
primary source of Hg emissions from indurating furnaces is from the Hg 
contained in the greenballs (i.e., unfired taconite iron ore pellets). 
The commenters provided Hg concentration data for greenballs from each 
taconite iron ore processing facility and recommended that the EPA 
revise the proposed Hg limits for new and existing furnaces to address 
the variability inherent in the Hg concentration of greenballs. They 
suggested the EPA use the data to develop a raw material variability 
factor that could be used when calculating the MACT floor limits for 
Hg. The commenters noted that the EPA had accounted for variability in 
the Hg concentration of raw materials when calculating the MACT floor 
limits for other NESHAP.
    Response: The EPA reviewed the Hg data submitted by industry and 
determined the data were not adequate for us to calculate a variability 
factor for use in deriving the MACT floor limits. This decision was 
based on several factors. First, the number of measurements submitted 
for each facility varied considerably--from as few as three 
measurements for the best performing furnace at Northshore (including 
two measurements on the same day) to as many as 948 measurements for 
the UTAC plant. The very limited data provided for Northshore is a 
concern because Northshore's stack test data showed that their furnace 
was the best performing (i.e., had the lowest emissions of Hg). The 
data provided for Northshore are insufficient to evaluate temporal 
variability in the Hg content of the greenballs at Northshore because 
the data consist of measurements made during only two greenball 
sampling episodes: one in January 1997 and the other in November 2001. 
Second, much of the data submitted could not be validated because the 
commenters did not provide the laboratory reports for the test results. 
For example, the UTAC facility provided 948 measurements of the Hg 
concentration of the greenballs at their plant but submitted none of 
the laboratory reports needed to corroborate their data. Laboratory 
reports are needed to determine whether appropriate methods were used 
for sample collection and analysis, to confirm appropriate quality 
assurance and quality control measures were taken, and to check that 
the values submitted are accurate. In total, we were unable to confirm 
the concentration values for over 87 percent of the measurements 
submitted because we lacked the laboratory reports. Third, the samples 
were collected at irregularly spaced intervals, often with large gaps 
in time during which no samples were collected. These sampling 
intervals varied from as little as a few days to multiple years. In 
cases where samples were collected over a period of several consecutive 
months, the measurements were not collected at consistent intervals. 
Ideally, the samples would be collected at representative intervals 
with supporting documentation of the sample collection and analysis, to 
avoid bias in the dataset. Finally, the data submitted for some 
facilities included measurements that we determined to be statistical 
outliers. For example, we identified two statistical outliers in the 
Tilden dataset, where in one case the Hg content of greenballs 
increased from 1.4 nanograms per gram (ng/g) on July 6, 2022, to 15.0 
ng/g on July 15, 2022, before decreasing to 1.2 ng/g on July 22, 2022. 
The presence of statistical outliers does not necessarily mean the

[[Page 16413]]

measurements are incorrect. However, statistical outliers raise 
concerns over the accuracy and representativeness of the measurements, 
particularly where no explanation for the anomaly is available.
    Comment: Some commenters requested EPA Method 30B be included as an 
acceptable alternative test method for measuring Hg emissions from 
indurating furnaces.
    Response: In response to the commenters' request, we reviewed EPA 
Method 30B and determined that this method is appropriate for measuring 
Hg emissions from indurating furnaces. In the final rule, we have 
updated the list of approved methods for Hg measurement to include EPA 
Method 30B, in addition to the proposed methods. The final rule allows 
owners and operators to use EPA Methods 29 or 30B in 40 CFR part 60, 
appendix A-8, and the voluntary consensus standard (VCS), 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).
    Comment: Industry commenters expressed concern that the proposed Hg 
stack testing volumes for performance testing to demonstrate compliance 
with the proposed Hg standards were too large such that each test run 
would require too much time to complete. They recommended that smaller 
test volumes would be appropriate and suggested that the test volume be 
small enough to allow each test run to be completed within 60 minutes.
    Response: In response to the commenters' concerns regarding the 
stack testing volumes and duration of each test run, the EPA 
reconsidered the proposed sample volume requirements and revised the 
performance testing requirements in the final rule to require a minimum 
sample volume of 1.7 dry standard cubic meters (dscm) (60 dry standard 
cubic feet (dscf)) for EPA Method 29 and ASTM D6784-16, instead of the 
3 dscm sample volume we proposed. The 1.7 dscm sample volume will allow 
test runs to be completed in approximately 2 hours while still ensuring 
that the required sample volume is sufficient for analysis and that a 
non-detect test result indicates compliance with the final Hg limits.
    Comment: We received multiple comments recommending continuous 
emission monitoring systems (CEMS) for Hg be included either as a 
requirement for all indurating furnaces or as an optional alternative 
to conducting performance testing and establishing operating limits. 
The commenters stated that CEMS would ensure continuous compliance with 
the Hg standard and could help lower compliance costs by making it 
possible for facilities to vary the ACI rate based on the Hg emissions 
data collected by CEMS. Some commenters said facilities would be more 
likely to use CEMS if the CEMS provisions were incorporated into the 
rule because facilities would not have to apply for approval of an 
alternative monitoring method.
    Response: The EPA agrees with recommendations made by commenters 
that suggested CEMS be included as an optional alternative to the 
proposed compliance monitoring and performance testing requirements. We 
agree that CEMS are an acceptable alternative monitoring method for 
assuring compliance with the Hg emissions standards. In the final rule, 
we have included provisions that provide owners and operators the 
option of using Hg CEMS in lieu of establishing operating limits and 
performing periodic performance testing. These provisions will provide 
more options for the methods that facilities can use to demonstrate 
compliance with the new Hg standards and reduce the burden associated 
with applying for Administrator approval of an alternative monitoring 
plan. However, we are not requiring installation of CEMS due to 
compliance cost considerations, as explained in the memorandum, 
Development of Impacts for the Final Amendments to the NESHAP for 
Taconite Iron Ore Processing, which is available in the docket for this 
action.
    Comment: Industry commenters were concerned that the proposed 
approach to setting operating limits for ACI would not allow facilities 
flexibility to adjust the carbon injection rates when production 
decreases. These commenters suggested the EPA allow flexibility to 
adjust the average ACI rate and average carrier flow rate based on 
taconite pellet production rates during stack testing to provide 
facilities with the operational flexibility needed at lower production 
rates.
    Response: We agree with the industry commenters that lower ACI and 
carrier gas flow rates would achieve compliance with the emission limit 
when production rates are lower than the production rates during the 
performance test used to establish operating limits. We have included 
provisions in the final rule that allow a facility to adjust the 
operating limits based on taconite pellet production. Under the 
requirements of the final rule, a facility has the option of 
establishing operating limits for different production rates by 
conducting performance tests at the maximum, minimum, and median 
taconite pellet production rates of an indurating furnace to develop a 
relationship between the carbon injection rate and taconite pellet 
production rate. An owner or operator would monitor the taconite pellet 
production rate and adjust the ACI rate in accordance with the 
relationship between these parameters developed during the performance 
testing. If the taconite pellet production rate falls below the minimum 
rate measured during performance testing, the owners and operators must 
maintain a carbon injection rate that is equal to, or above, the rate 
determined during the performance testing completed at the minimum 
taconite production rate.
    As an alternative, an owner or operator may adjust the ACI rate 
based on the direct measurement of Hg emitted to the atmosphere. An 
owner or operator must install, calibrate, maintain, and operate CEMS 
to measure Hg emissions from each emission stack associated with the 
indurating furnace to use this alternative.
    Comment: Industry commenters supported the EPA's decision to set 
the Hg emissions standards at the MACT floor rather than setting a BTF 
standard. Industry commenters stated that the capital and annual costs 
required to comply with the MACT floor are too high and setting BTF 
standards would not be cost-effective. One commenter asserted that any 
standard beyond the MACT floor must be justified by a ``thorough and 
robust analysis of the costs and benefits.'' The commenter agreed with 
the EPA's proposed determination that the cost-effectiveness of the BTF 
options identified for Hg control were above the level historically 
found to be reasonable.
    Several other commenters recommended the EPA set a BTF Hg standard 
and recommended the standard be at least 30-40 percent more stringent 
than the MACT floor. The commenters stated that additional Hg 
reductions can be achieved and that a more stringent Hg standard is 
warranted due to the bioaccumulative nature of Hg. The commenter noted 
that many water bodies located near taconite facilities already have 
fish consumption advisories, which commenters noted impact the rights 
of tribes to exercise their traditional life practices. One commenter 
noted that tribes have a particular interest in Hg emissions due to the 
Hg-related fish consumption advisories that have been issued by 
Minnesota since the 1970s and by the Fond du Lac Tribe beginning in 
2000. One commenter stated that the 30

[[Page 16414]]

percent BTF option would reduce Hg emissions to a level that would help 
address public health concerns associated with high concentrations of 
Hg in water, fish tissues, and other subsistence resources. Commenters 
from several tribes located near taconite facilities stated that the 
EPA's Tribal trust and treaty responsibilities justified adoption of a 
BTF option. They added that the EPA should consider its trust 
responsibility to protect the interests of tribes and the tribes' 
treaty rights and quoted from two EPA policy documents: EPA Policy for 
the Administration of Environmental Programs on Indian Reservations 
(issued November 1984) and Guidance for Discussing Tribal Treaty Rights 
(issued February 2016). Both documents support consideration of Tribal 
rights and protections in Agency decision making. Commenters noted that 
the areas impacted by taconite iron ore processing plants are in the 
areas covered by a series of treaties. These commenters disagreed with 
the EPA's determination that BTF options were not cost-effective.
    Response: The EPA agrees with the commenters that said the Hg 
standard should be set at the MACT floor. In our analysis, the BTF 
options were above the numbers we have found cost effective for Hg 
controls in prior CAA section 112 rulemakings.
    The EPA recognizes the Federal government's trust responsibility, 
which derives from the historical relationship between the Federal 
government and Indian Tribes. The EPA acts consistently with the 
Federal government trust responsibility by implementing the statutes it 
administers and consulting with and considering the interests of tribes 
when taking actions that may affect them. As we noted in the proposal, 
the EPA consulted with Tribal government officials during the 
development of this rule. The EPA's Office of Air and Radiation held a 
meeting with the Fond du Lac Band of Lake Superior Chippewa Reservation 
and the Leech Lake Band of Ojibwe Reservation on January 12, 2022, to 
discuss the EPA's CAA section 114 information request, and to ensure 
that the views of affected tribes were taken into consideration in the 
rulemaking process in accordance with the EPA Policy on Consultation 
and Coordination with Indian Tribes. A summary of that consultation is 
provided in the document, Consultation with the Fond du Lac Band of 
Lake Superior Chippewa and the Leech Lake Band of Ojibwe regarding 
Notice of Proposed Rulemaking for the National Emission Standards for 
Hazardous Air Pollutants for Taconite Iron Ore Processing Amendments on 
January 12, 2022, which is available in the docket for this action.
    The Agency recognizes the concerns raised by numerous Tribal 
commenters regarding impacts to treaty fishing and other resource 
rights. However, for the reasons explained below, the EPA is declining 
to set BTF standards for Hg, based on the statutory factors that we are 
required to consider pursuant to CAA section 112(d)(2) when assessing 
whether to set MACT standards more stringent than the MACT floor level 
of control. These statutory factors include the cost of achieving such 
emission reduction, and any non-air quality health and environmental 
impacts and energy requirements. As discussed in paragraphs later in 
this section, the cost-effectiveness values associated with BTF 
standards for this Taconite Iron Ore Processing rule are well above the 
cost-effectiveness values that EPA has historically accepted when 
considering BTF options for regulating mercury emissions. We note that 
the historic acceptable cost-effectiveness values for mercury (e.g., up 
to $22,400 per pound [in 2007 dollars] in the 2011 final MATS rule, 
which equates to about $32,000 per pound in current dollars) are much 
higher than the cost-effectiveness values we have accepted for all 
other HAPs (except for maybe a few exceptions such as dioxins and 
furans) and is based, at least in part, on the fact that mercury is a 
persistent, bioaccumulative, toxic (PBT) HAP. Nevertheless, we conclude 
that setting BTF Hg standards in this rule would be inconsistent with 
the values found to be cost-effective for Hg controls in prior 
rulemakings. We are declining to set BTF standards in this rule based 
on cost and other statutory factors.
    Section 112(d) of the CAA requires the EPA to set emissions 
standards for HAP emitted by sources in each source category and 
subcategory listed under CAA section 112(c). The MACT standards for 
existing sources must be at least as stringent as the average emissions 
limitation achieved by the best performing 12 percent of existing 
sources (for which the Administrator has emissions information) or the 
best performing five sources for source categories with less than 30 
sources (CAA sections 112(d)(3)(A) and (B)). This level of minimum 
stringency is called the MACT floor. For new sources, MACT standards 
must be at least as stringent as the control level achieved in practice 
by the best controlled similar source (CAA section 112(d)(3)). The EPA 
may not consider costs or other impacts in determining the MACT floor.
    Section 112(d)(2) of the CAA also requires the EPA to examine 
emission standards more stringent than the MACT floor, which the EPA 
refers to as BTF control options. Unlike standards set at the MACT 
floor level of control, when assessing whether to require emission 
standards more stringent than the MACT floor, the EPA must consider the 
cost of achieving such emission reduction, and any non-air quality 
health and environmental impacts and energy requirements. The EPA's BTF 
analysis evaluated these factors in determining whether to establish Hg 
standards more stringent than the MACT floor. In developing this final 
rule, we evaluated Hg emission limits more stringent than the MACT 
floor after adjusting estimates of Hg emissions, Hg emission 
reductions, and control costs as discussed above, including those BTF 
limits suggested by commenters, to assess whether a BTF option was 
technically achievable and cost-effective. We estimate that the total 
capital costs and total annual costs would range from a low of $137 
million and $92 million, respectively, for a limit that is 10 percent 
more stringent than the floor to a high of $148 million and $102 
million, respectively, for a limit that is 40 percent more stringent 
than the floor. The incremental cost effectiveness for the BTF options 
examined varied from a low of $46,266 per pound of Hg reduced for 30 
percent more stringent than the floor to a high of $91,140 per pound of 
Hg reduced for 40 percent more stringent than the floor. These values 
are well above the $/pound of Hg reduced that we have historically 
found to be cost-effective when considering BTF options for regulating 
Hg emissions. Where EPA has taken costs into account, the Agency has 
finalized standards for mercury with cost effectiveness estimates of up 
to $32,000/lb Hg reduced (adjusted to 2024 dollars). See Mercury Cell 
Chlor-Alkali Plants Residual Risk and Technology Review (87 FR 27002, 
May 6, 2022); 2011 Mercury and Air Toxics (MATS) final rule. To date, 
these are the highest cost-effectiveness values that we have accepted 
in the air toxics program for any HAP (except for maybe a few 
exceptions such as dioxins and furans), largely because of the toxicity 
and nature of Hg. While we conclude that mercury standards more 
stringent than the MACT floor are not cost-effective, we note that as a 
result of the revisions to the rule being finalized in this rulemaking, 
we will receive compliance test information that will allow us to 
evaluate our conclusions and potentially inform appropriate future

[[Page 16415]]

regulatory activities including the next statutorily required 
technology review. Mercury is one of the high concern HAPs because it 
is environmentally persistent, it bioaccumulates in humans and food 
chains--including in fish, which is a concern for subsistence needs, 
uses and cultural practices as noted in multiple comments from Tribes--
and is a neurotoxin that is especially of concern for developing 
fetuses and young children. For these reasons, mercury is one of the 
few HAPs for which we use the expression of $ per pound and consider 
higher cost-effectiveness values. We also estimated the secondary 
impacts of the BTF options would range between 155,000 megawatt-hours 
per year (MWh/yr) and 160,000 MWh/yr of electricity (with associated 
secondary air emissions), generate between 4.7 million and 7.4 million 
gallons of wastewater per year, and produce between 110,000 tons and 
112,000 tons of solid waste of per year. Based on our assessment of Hg 
emission standards 10 percent, 20 percent, 30 percent, and 40 percent 
more stringent than the MACT floor, including consideration of cost and 
other statutory factors of setting BTF Hg standards for indurating 
furnaces in the source category as specified in CAA section 112(d)(2), 
in the final rule, we are declining to adopt BTF emission standards for 
Hg and are finalizing Hg standards at the MACT floor as discussed in 
section III.A.3 of this preamble. For more information on our analysis 
of the BTF control options for Hg, please see the memorandum, Final 
Maximum Achievable Control Technology (MACT) Analysis for Mercury 
Standards for Taconite Iron Ore Indurating Furnaces, which is available 
in the docket for this action.
    Comment: Several commenters, including the National Park Service, 
several local tribes, and environmental organizations said Hg standards 
for the taconite industry were important because of the benefits lower 
Hg emissions will have on public health and the environment. One 
commenter cited several studies, such as the Dragonfly Mercury Project, 
that document elevated levels of Hg and higher risks of Hg exposure to 
humans and wildlife in the Great Lakes Region. This commenter stated 
that the upper Great Lakes Region is particularly sensitive to Hg 
pollution due to the abundance of wetlands and peatlands, low-pH lakes, 
high dissolved organic matter, low biological productivity, and other 
factors that provide conditions suitable for the conversion of Hg to 
the bioavailable form methylmercury. The commenter also stated the 
impacts of Hg on wildlife include reduced foraging efficiency, lower 
reproductive success, impaired endocrine modulation, and damage to 
kidney and other tissues. The commenters expressed concern over the 
number of fish with Hg levels exceeding the human and wildlife health 
thresholds. The commenter cited data from a 1998-2016 study that 
measured Hg concentrations in fish from the upper Great Lakes at 0.12 
ppm wet weight, with 24 percent of the fish sampled exceeding the EPA 
human health criterion of 0.3 ppm wet weight, 27 percent of the fish 
exceeding fish-eating wildlife health threshold of 0.2 ppm whole-body, 
and 17 percent exceeding the fish toxicity benchmark of 0.3 ppm whole-
body. This commenter cited studies linking Hg deposition with 
bioaccumulation, including a study of Hg concentration in moose teeth 
from Isle Royale National Park, Michigan from 1952 to 2002. The 
commenter noted that Hg decreased by about two-thirds during the early 
1980s but remained constant for the following 2 decades. The commenter 
cited an additional six studies that analyzed the concentrations and 
trends of Hg in bald eagle nestlings in the upper Midwest from 2006-
2015 and long-term trends at two Lake Superior sites between 1989-2015. 
These studies show concentrations of Hg in nestling breast feathers 
were highest at the Saint Croix National Scenic Riverway (6.66 
[micro]g/g wet weight) and that Hg concentrations have increased at two 
other study area sites.
    The commenters said the new Hg standards will help reduce Hg 
deposition in the Great Lakes Region and improve public health. The 
commenters asserted that taconite iron ore processing plants in 
Minnesota and Michigan have a significant impact on the natural 
resources of the upper Great Lakes Region and the elevated Hg levels in 
fish and bird populations. Several commenters mentioned the statewide 
fish consumption advisories for Hg in Minnesota, Michigan, and 
Wisconsin and noted several water bodies in these states are listed as 
impaired for aquatic consumption due to Hg. The commenters asserted 
that the new Hg standards will reduce the impact of Hg on public health 
and the environment, provide additional protection to recreational and 
subsistence fish consumers in national parks and surrounding 
communities, and protect natural resources that are of cultural 
significance to many local communities.
    Response: The EPA acknowledges the independent research conducted 
by the National Park Service and others on the impacts of Hg on the 
communities and wildlife of the upper Great Lakes Region. We share the 
commenters' concern about the elevated Hg levels in fish and other 
wildlife in Minnesota, Wisconsin, and Michigan, and the critical impact 
these Hg levels have on tribes and low-income populations that rely on 
the fish and wildlife from the Great Lakes region. By controlling Hg 
emissions, the Hg MACT standards EPA is finalizing in this action for 
taconite iron ore processing plants will achieve an estimated reduction 
of 247 pounds per year of mercury emissions from the Taconite 
facilities, which we expect will also achieve an unquantified reduction 
of Hg deposition in the Great Lakes Region and therefore improve public 
health of local communities, including local tribes and low-income 
populations.
3. What are the final MACT standards for Hg and how will compliance be 
demonstrated?
    We are finalizing MACT standards for Hg for new and existing 
indurating furnaces that reflect the MACT floor level of control, based 
on the 99-percent UPL, of 1.4 x 10<SUP>-5</SUP> lb/LT for existing 
sources and 2.6 x 10<SUP>-6</SUP> lb/LT for new sources. We are also 
finalizing the emissions averaging compliance alternative that allows 
taconite iron ore processing facilities with more than one existing 
indurating furnace to comply with a Hg emissions limit of 1.3 x 
10<SUP>-5</SUP> lb/LT by averaging emissions on a production-weighted 
basis for two or more existing indurating furnaces located at the same 
facility.
    Owners and operators may demonstrate compliance with the new Hg 
standards in one of two ways. Under the first option, an owner or 
operator may demonstrate compliance by completing performance testing 
and establishing operating limits for each control device used to 
comply with the Hg standard. The final rule clarifies that performance 
testing must be performed when the production rate is equal to or 
greater than 90 percent of the capacity of the indurating furnace. If 
the performance testing cannot be performed when the production rate is 
equal to or greater than 90 percent of the production rate capacity of 
the furnace, the owner or operator may complete testing at a lower 
production rate if they receive approval from the delegated authority. 
An owner or operator selecting this option must install and operate 
continuous parameter monitoring systems (CPMS) to monitor the 
parameters specified in 40 CFR 63.9631(g). An owner or operator must 
take corrective action when an established operating limit is exceeded.

[[Page 16416]]

The initial performance testing must be completed within 180 calendar 
days of the compliance date specified in 40 CFR 63.9583(f) for existing 
sources or within 180 calendar days of startup for new sources, using 
EPA Methods 29 or 30B in 40 CFR part 60, appendix A-8 or the VCS 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). The performance tests must be repeated 
at least twice per 5-year permit term.
    The second option by which an owner or operator may demonstrate 
compliance is through the installation and operation of CEMS for Hg. 
The CEMS must be installed, calibrated, maintained, and operated in 
accordance with the procedures specified in 40 CFR 63.9631(j). An owner 
or operator selecting this approach is not required to establish 
operating limits, install and operate CPMS, or complete the initial and 
periodic performance testing for Hg emissions.
    As discussed in section III.A.2 of this preamble, the final rule 
includes an option for adjusting the carbon injection rate based on the 
taconite pellet production level. The facility has the option of 
establishing operating limits for different production rates by 
conducting performance tests at the maximum, minimum and median 
taconite pellet production rates to develop a relationship between 
carbon injection rate and taconite pellet production rate or by 
adjusting the ACI rate based on Hg emissions data collected by CEMS. 
Facilities that elect to adjust the carbon injection rate based on 
taconite production levels will have lower compliance costs due to 
lower annual consumption of activated carbon.
    Each owner or operator must prepare a preventive maintenance plan 
and keep records of calibration and accuracy checks of the CPMS or CEMS 
to document proper operation and maintenance of all monitoring systems 
used to demonstrate compliance with the applicable Hg standard.

B. Revised Emission Standards for HCl and HF

1. What did we propose for the Taconite Iron Ore Processing source 
category?
    As described in the May 15, 2023, proposal (88 FR 30917), we 
proposed to revise the numerical emission limits for HCl and HF, 
pursuant to CAA section 112(d)(6). CAA section 112(d)(6) requires the 
EPA to review standards promulgated under CAA section 112 and revise 
them ``as necessary (taking into account developments in practices, 
processes, and control technologies)'' no less often than every 8 
years; we refer to such action under CAA section 112(d)(6) as a 
``technology review.'' The EPA previously completed a technology review 
for the Taconite Iron Ore Processing source category in 2020 (85 FR 
45476; July 28, 2020). In the May 15, 2023, proposal, we proposed to 
revise the HCl and HF standards based on new information we obtained in 
response to the 2022 information collection concerning emissions of 
these pollutants from the source category. For existing indurating 
furnaces, we proposed emissions standards of 4.4 x 10<SUP>-2</SUP> lb/
LT for HCl and 1.2 x 10<SUP>-2</SUP> lb/LT for HF. For new indurating 
furnaces, we proposed emission standards of 4.4 x 10<SUP>-4</SUP> lb/LT 
for HCl and 3.3 x 10<SUP>-4</SUP> lb/LT for HF. We proposed to require 
that owners or operators demonstrate compliance through initial and 
periodic performance testing (completed at least twice per 5-year 
permit term), establishing operating limits for each control device 
used to comply with the HCl and HF standards, and installing and 
operating continuous parameter monitoring systems (CPMS) to ensure 
continuous compliance with the standards.
2. What comments did we receive on the proposed revised HCl and HF 
emission standards, and what are our responses?
    Comment: We received comments and data from industry identifying 
errors in the emissions data for the Tilden and Hibbing indurating 
furnaces submitted to the EPA in response to the CAA section 114 
information request sent to the taconite facilities in 2022. For the 
Tilden stack test report, industry confirmed the units of measure were 
incorrectly listed in the stack test report submitted by industry as 
``pounds per ton'' instead of ``pounds per long ton'' of taconite 
pellets produced. Commenters confirmed the units of measure should be 
``pounds per long ton.'' For Hibbing, the commenters identified one 
transcription error in the HCl emissions data for one of the four 
emission stacks.
    Response: In response to these comments, the EPA reviewed all stack 
test runs for the seven furnaces that completed HCl and HF stack 
testing pursuant to the 2022 CAA section 114 information request. We 
confirmed there was a transcription error in HCl emissions for the 
first run of the stack testing completed on the Hibbing furnace. Since 
the emissions data for Hibbing were included in the dataset used to 
calculate the proposed HCl emission limit, we recalculated the emission 
limit for HCl using the revised data. As a result of the changes to the 
Hibbing emissions data, the numerical emission standard for HCl for 
existing sources was revised from the proposed 4.4 x 10<SUP>-2</SUP> 
lb/LT to the 4.6 x 10<SUP>-2</SUP> lb/LT limit we are finalizing in 
this action. The revisions to the emissions data do not impact the 
numerical limit for HCl for new sources or the numerical limits for HF 
for new and existing sources. Therefore, the proposed HCl standard for 
new sources of 4.4 x 10<SUP>-4</SUP> lb/LT and the HF standards for new 
and existing sources of 3.3 x 10<SUP>-4</SUP> lb/LT and 1.2 x 
10<SUP>-2</SUP> lb/LT, respectively, are finalized without change.
    The EPA revised the units of measure for the Tilden HCl and HF 
emission data based on the comments we received from industry. As we 
explained in the proposal, the HCl and HF emissions data for the Tilden 
furnace are not used to calculate the emission limits for HCl and HF 
because Tilden's furnaces use dry electrostatic precipitators (ESP). In 
the proposal, we stated that we expect Tilden's two indurating furnaces 
would be able to meet the HF limit for existing furnaces without adding 
any air pollution control devices but that we expect Tilden would be 
required to add air pollution control devices to meet the proposed HCl 
emission standard. Although the revised emission rates for Tilden are 
slightly lower than the emissions rates used for the proposal, we 
expect that Tilden's furnaces would still need to add air pollution 
controls to meet the HCl emission standard we are finalizing for 
existing furnaces. As explained in the previous paragraph, the EPA is 
finalizing the HCl emission standard of 4.6 x 10<SUP>-2</SUP> lb/LT for 
existing sources. To comply with the HCl emission standard, Tilden must 
reduce HCl emissions by 76 percent (compared to 79 percent HCl 
reduction we estimated at proposal) and the HCl emissions reduction for 
the final rule is 683 tpy (compared to a 713 tpy reduction we estimated 
at proposal). Our revised total capital cost estimate for HCl controls 
(dry sorbent injection) is $1.1 million and our revised annual cost 
estimate is $1.4 million. The revised cost effectiveness is $2,040 per 
ton of HCl removed, which is a level of cost effectiveness that is 
acceptable for HCl and would also likely be acceptable for any other 
HAP. The revised emissions data, numerical limits, and cost estimates 
prepared for the final rule are documented in the memorandum, Final 
Revised Technology Review of Acid Gas Controls for Indurating

[[Page 16417]]

Furnaces in the Taconite Iron Ore Processing Source Category, which is 
available in the docket for this action.
    Comment: Multiple commenters were supportive of replacing PM as a 
surrogate for HCl and HF emissions and supported the proposed numerical 
emission limits for HCl and HF. One commenter said the PM limit was not 
a valid surrogate for emissions of HCl and HF and argued the EPA should 
set HCl and HF limits under the provisions of CAA section 112(d)(2) and 
(3). However, other commenters from industry disagreed with our 
proposal and said the existing standards based on PM as a surrogate for 
acid gases should not be changed. These commenters asserted that the 
EPA lacked the authority to revise the existing HCl and HF standards 
because the EPA had not shown that technological developments have 
occurred that would lower emissions of acid gases nor shown that 
revisions are necessary, as required by CAA section 112(d)(6). The 
commenters stated that new emissions data does not qualify as a 
development under CAA section 112(d)(6) and that the language in CAA 
section 112(d)(6) focuses on actual control measures and requires the 
EPA to update an existing emissions standard only if improvements in 
control measures occur and the improvements in control measures warrant 
a revision. The commenters added that PM is still recognized as a 
proper surrogate for HAP emissions and the revised standards are 
unnecessary because they impose a significant financial burden on 
taconite iron ore processing plants without reducing risks to the 
public health and the environment.
    Response: The EPA agrees that revising the emission limits for HCl 
and HF is appropriate for the reasons explained in this discussion, 
below, and in the proposal preamble (88 FR 30926). We disagree that the 
EPA lacks authority to revise the existing standards for HCl and HF. 
When the NESHAP for the Taconite Iron Ore Processing source category 
was first developed, PM emission limits were used as a surrogate for 
HCl and HF. The decision to use the PM standards as a surrogate for HCl 
and HF emissions was based on an analysis of the HCl, HF, and PM 
emissions data that the EPA possessed at the time of promulgation of 
the initial NESHAP for the Taconite Iron Ore Processing source category 
in 2003 (68 FR 61868; October 30, 2003). That data indicated there was 
a correlation between acid gas and PM emissions. We note, however, that 
the use of PM as a surrogate for HCl and HF and the corresponding PM 
emission limit were based on a limited dataset because only three 
furnaces conducted PM emissions tests concurrently with the HCl and HF 
tests. As part of the 2022 CAA section 114 information request, the EPA 
sought emissions data from Taconite Iron Ore Processing facilities, 
including stack testing for PM, HCl, and HF emissions from seven 
indurating furnaces located at six taconite facilities. The data 
received in response to the 2022 CAA section 114 information request 
are presented in the memorandum, Final Emissions Data Collected in 2022 
for Indurating Furnaces Located at Taconite Iron Ore Processing Plants, 
which is available in the docket for this action. The 2022 dataset is 
not only more robust than the limited dataset available in 2003 but 
also more representative of current conditions since some of the 
control devices used on the furnaces at the time of the 2003 rulemaking 
have changed since that time. For example, the Keetac plant has since 
replaced the multicyclones on their indurating furnace with venturi 
scrubbers and the Tilden plant replaced a wet ESP on one stack with a 
dry ESP. Based on this new data, we determined it was more appropriate 
to directly regulate the HAP of concern than to use a surrogate. Our 
analysis of the 2022 data and our review of available air pollution 
controls for acid gases indicates that the controls we expect will be 
necessary to meet the numerical standards for HCl and HF are available 
and cost-effective. As we explained in the proposal (88 FR 30926), the 
new data received in response to the 2022 CAA section 114 information 
request showed that indurating furnaces using wet scrubbers achieve 
better control of HCl and HF than furnaces using dry ESP.
    We disagree with commenter that we lack the authority to revise 
standards pursuant to CAA section 112(d)(6) absent a showing that the 
revisions would reduce risk. CAA section 112(d)(6) requires the EPA to 
review and revise as necessary emission standards taking into account 
developments in practices, processes, and control technologies. This 
provision does not require the EPA to consider risk. We agree that the 
EPA has the discretion to consider cost when considering the 
appropriate level of control under CAA section 112(d)(6). The EPA 
identified dry sorbent injection (DSI) and wet scrubbers as a feasible 
control options and estimated the associated costs. We concluded that 
DSI is the lowest cost option for the indurating furnaces located at 
the Tilden plant. Based on this analysis, the EPA concluded the costs 
to comply with the numerical limits for HCl were justified and cost-
effective and do not impose a significant financial burden on industry. 
The cost effectiveness was estimated to be $2,040 per ton of HCl 
removed, which is within the range the EPA has previously considered to 
be a cost-effective level of control for many HAP. Based on the 2022 
emissions data, add on air pollution controls are not required to meet 
the HF emission limit. The standards we are finalizing in this action 
ensure HCl and HF emissions from all indurating furnaces in the source 
category are controlled to the same extent as the best performing 
indurating furnaces in the source category.
    Comment: Industry commenters stated there is no basis for changing 
the way HCl and HF emissions are regulated, that the EPA did not 
explain why PM cannot be used as a surrogate for HCl and HF emissions, 
and that if revised standards were needed, they should be based on the 
subcategories established in the Taconite Iron Ore Processing NESHAP in 
2003. The commenters stated that the EPA should make determinations on 
whether new standards are necessary for each subcategory and then 
should base any new standards for each subcategory on emission data for 
the furnaces within that subcategory. The commenters acknowledged that 
CAA section 112(d)(6) authorizes the EPA to review and revise as 
necessary the emission standards every 8 years, but they said the 
statute does not permit the EPA to develop new standards ignoring the 
existing subcategories. The commenters argued the Tilden facility 
processes a different type of taconite ore (i.e., hematite instead of 
magnetite) than the other facilities and therefore the furnaces at this 
facility should remain in a separate subcategory from the furnaces at 
the other facilities (as was the case when the EPA established the PM 
standards in the 2003 NESHAP). The commenters noted that a subcategory 
was established for grate kilns processing hematite ore because of 
differences in the ore and furnace, including different air flow 
direction and rates, the perpetual motion of the pellets inside the 
kiln, fineness of the hematite ore, tendency for the hematite pellets 
to break, and production of fluxed pellets that use limestone/dolomite 
containing chloride. For furnaces that process magnetite, the 
commenters argued that limits for HCl and HF are not needed and would 
result in unnecessary compliance costs

[[Page 16418]]

without health and environmental benefits.
    Response: We disagree with the industry commenters' assertion that 
the EPA should extend the subcategorization for PM standards used in 
the 2003 rulemaking and set HCl and HF limits only for grate kilns 
processing hematite ore. When the NESHAP for the Taconite Iron Ore 
Processing source category was initially developed, indurating furnaces 
were identified as significant sources of HCl and HF emissions. The 
NESHAP promulgated in 2003 established limits, as required under CAA 
section 112(d), for all indurating furnaces. The decision to use the PM 
standards as a surrogate for HCl and HF emissions was based on very 
limited HCl, HF, and PM emissions data available and evaluated for the 
2003 rulemaking. As we explained in the response to the previous 
comment, in this action, we have determined it is more appropriate to 
directly regulate the HAP of concern (i.e., HCl and HF) than to use a 
surrogate, using the more robust 2022 dataset now available to us. The 
data collected for this rulemaking are presented in the memorandum, 
Final Emissions Data Collected in 2022 for Indurating Furnaces Located 
at Taconite Iron Ore Processing Plants, which is available in the 
docket for this action.
    We disagree with commenters' assertion that emission limits for 
acid gases should be established using the existing subcategories for 
PM and that HCl and HF standards are not necessary for furnaces that 
process magnetite ore. The EPA found in the 2003 NESHAP final rule that 
HCl and HF are emitted by all indurating furnaces and established 
standards for all types of indurating furnaces in the Taconite Iron Ore 
Processing source category, including those indurating furnaces that 
process magnetite ore. Indeed, the emissions data collected in response 
to the 2022 CAA section 114 information request demonstrate that 
indurating furnaces processing magnetite ore emit measurable levels of 
HCl and HF even after control by wet scrubbers. HCl and HF are formed 
in indurating furnaces due to the presence of chlorides and fluorides 
in the raw materials used to form the greenballs (i.e., unfired 
taconite pellets) that are fed into the indurating furnaces. While some 
of the chlorides and fluorides in the raw materials come from the ore, 
pellet additives, such as dolomite and limestone, are also a source of 
HCl and HF emissions. These additives are routinely used by all 
taconite plants, including those that process magnetite ore. Although 
the commenters suggested plants processing hematite ore using grate-
kilns should be considered a separate subcategory when considering acid 
gas emissions, the commenters provided no data demonstrating a 
significant difference in the chloride and fluoride content of the two 
types of ores. Nor did they provide any explanation or data to support 
their assertion that differences in the design of the indurating 
furnace impact HCl and HF emissions. The data pertaining to indurating 
furnaces processing magnetite ore that was collected in response to the 
2022 CAA section 114 information request does not show a significant 
difference in acid gas emissions between straight-grate and grate kiln 
indurating furnaces.
    Pursuant to CAA section 112(d)(1), the Administrator ``may 
distinguish among classes, types, and sizes of sources within a 
category or subcategory in establishing'' standards. However, as we 
have discussed in previous Agency actions, the CAA does not mandate 
that the EPA create subcategories. See, e.g., National Emission 
Standards for Hazardous Air Pollutants From Coal- and Oil-Fired 
Electric Utility Steam Generating Units and Standards of Performance 
for Fossil-Fuel-Fired Electric Utility, Industrial-Commercial-
Institutional, and Small Industrial-Commercial-Institutional Steam 
Generating Units (77 FR 9304, 9378; February 16, 2012) (``2012 Mercury 
and Air Toxics Final Rule''). In addition, the Agency may create 
subcategories for the purpose of regulating specific HAP, while 
declining to create subcategories more broadly. In the 2012 Mercury and 
Air Toxics Final Rule, we explained the Agency's position that any 
basis for subcategorization (i.e., class, type, or size) typically must 
be related to an effect on HAP emissions that is due to the difference 
in class, type, or size of the sources. We further explained that 
``[e]ven if we determine that emissions characteristics are different 
for units that differ in class, type, or size, the Agency may still 
decline to subcategorize if there are compelling policy justifications 
that suggest subcategorization is not appropriate'' (77 FR 9378). In 
the 2012 Mercury and Air Toxics Final Rule, we determined it was 
appropriate to subcategorize coal-fired boilers for purposes of 
regulating Hg emissions based on differences in Hg emissions between 
two types of coal-fired boiler subcategories. We also determined that 
for all other HAP, the data did not show any difference in HAP emission 
levels, and we declined to set separate emission standards for the two 
types of coal-fired boilers for other HAP.
    In this final rule, we are retaining the separate PM emission 
limits established in the 2003 final rule for indurating furnaces 
processing magnetite and hematite. Based on the data available, we 
continue to believe it is appropriate to retain these separate PM 
emission standards because hematite is a finer grained ore than 
magnetite, and processing of hematite in an indurating furnace results 
in higher PM emissions than processing magnetite. However, we are 
declining to subcategorize taconite indurating furnaces for purposes of 
regulating Hg or acid gas emissions. As explained previously, pursuant 
to CAA section 112(d)(1), the EPA has the discretion to subcategorize 
sources for the purpose of setting emission standards under CAA section 
112, but is not required to do so. As we also explained, where the EPA 
elects to subcategorize sources, we typically do so for the purpose of 
setting standards for specific HAP where the basis for the 
subcategorization is related to an effect on HAP emissions that is due 
to a difference in class, type, or size of the sources. The differences 
in emissions of HCl and HF among taconite indurating furnaces are 
largely the result of differing controls utilized by sources rather 
than a result of the class, type, or size of the indurating furnaces 
themselves. Therefore, we conclude that the differences in HCl and HF 
emissions are not due to differences in the class, type, of size of 
taconite indurating furnaces. As a result, we do not believe it is 
appropriate to subcategorize taconite indurating furnaces for the 
purpose of regulating Hg, HCl, or HF emissions and are declining to do 
so in this final rule.
    Based on the data available, the EPA proposed to set HCl and HF 
emission standards that apply to all indurating furnaces. In this 
action, we are finalizing emission standards for HCl and HF as 
discussed in section III.B.1 of this preamble. While the HCl emission 
standard for existing furnaces differs from what we proposed for the 
reasons explained in section III.B.2 of this preamble, we continue to 
believe it is appropriate to set numerical emission standards for HCl 
and HF based on the 2022 ICR data rather than to continue to rely on PM 
standards as a surrogate for these pollutants. While we expect that 
most indurating furnaces will be able to meet the revised HCl and HF 
limits using existing air pollution controls, the new performance 
testing and parametric monitoring requirements are necessary to ensure 
continuous compliance with the HCl and HF emission standards. The

[[Page 16419]]

PM testing and monitoring requirements in the current NESHAP designed 
to ensure compliance with the PM emission standards, which will remain 
in place as surrogates for non-Hg metal HAP, are not sufficient to 
demonstrate compliance with the HCl and HF emission standards. Each 
owner and operator must complete performance testing, establish 
operating limits for each control device used to control HCl and HF, 
and monitor the appropriate parameters to demonstrate the control 
device is operating in a manner that ensures compliance with the HCl 
and HF emission standards. Performance testing must be completed at 
least twice per 5-year permit term and within 180 days of startup of 
new furnaces.
    Comment: Industry commenters asserted the data used to develop the 
numerical standards for HCl and HF was too limited to reflect the 
operational and seasonal variability in the HCl and HF emissions. They 
stated that several factors influence the HCl and HF emissions and that 
the emissions data received in response to the 2022 CAA section 114 
information request covers too short of a time period to be 
representative of the acid gas emissions from indurating furnaces. The 
commenters noted that HCl and HF emissions are driven by the chloride 
or fluoride content in the iron ore and that the limited dataset does 
not account for the full range of variability in the chlorine and 
fluorine content of raw materials. They stated that the raw materials 
vary throughout a taconite mine, producing raw materials with different 
compositions and characteristics that are not reflected in the 2022 CAA 
section 114 information request data. The commenters recommended the 
HCl and HF limits be based on a more representative dataset collected 
over a longer period of time that accounts for raw material variation 
as well as seasonal and operational variation. The commenters stated 
that because the proposed limits are based on a limited dataset that 
does not fully account for operational variability, the proposed HCl 
and HF emission limits should not be finalized and they recommended 
that the PM standards in the current NESHAP continue to be used as a 
surrogate for acid gas emissions.
    Response: The method used to calculate the proposed numeric 
emission limits for HCl and HF for new and existing taconite indurating 
furnaces has been used for several years to set numerical limits for 
other source categories and is an appropriate methodology that accounts 
for variability in the emissions between different furnaces and 
different plants and accounts for some variability in the chloride and 
fluoride content of the ore and pellet additives used at different 
facilities because it includes data from two different types of 
indurating furnaces (straight grate furnaces and grate kiln furnaces) 
at five different taconite facilities. We used the emissions data from 
the six indurating furnaces currently using wet scrubbers to calculate 
a UPL. The UPL approach encompasses all the data point-to-data point 
variability within the sample set (i.e., all of the emissions data from 
the six indurating furnaces equipped with wet venturi scrubbers), which 
consisted of 21 individual data points. The UPL was calculated as the 
mean of the 21 data points plus a factor that accounts for the 
variability within the dataset. The UPL represents the value which one 
can expect the mean of a specified number of future observations (e.g., 
3-run average) to fall below at a specified level of confidence based 
upon the results of an independent sample from the same population. We 
used a 99-percent level of confidence to calculate the UPL, which means 
that a facility that uses the same or similar type of air pollution 
control device(s) has one chance in 100 of exceeding the emission 
limit. A prediction interval for a single future observation (or an 
average of several test observations) is an interval that will, with a 
specified degree of confidence, contain the next (or the average of 
some other pre-specified number of) randomly selected observation(s) 
from a population. The UPL estimates what the upper bound of future 
values will be based upon present or past background samples taken. 
While larger datasets are always preferable, numerical emission limits 
are often based on data from a single stack test event. For additional 
information on the methodology used to develop the numerical emission 
standards for HCl and HF for the final rule, please see the memorandum, 
Final Revised Technology Review of Acid Gas Controls for Indurating 
Furnaces in the Taconite Iron Ore Processing Source Category. A copy of 
this document is available in the docket for this action.
3. What are the revised standards for HCl and HF and how will 
compliance be demonstrated?
    We are finalizing numerical emission limits for HCl and HF, 
pursuant to CAA section 112(d)(6). We are finalizing as proposed the 
numerical emission limit for HCl for new indurating furnaces. We are 
finalizing a numerical emission limit for HCl for existing indurating 
furnaces which differs from the limit proposed because the final limit 
reflects a revision to the emissions data for the Hibbing facility, as 
discussed in section III.B.2 of this preamble. We are finalizing as 
proposed the numerical emission limits for HF for new and existing 
indurating furnaces. For existing indurating furnaces, we are 
finalizing an HCl emission limit of 4.6 x 10<SUP>-2</SUP> lb/LT and are 
finalizing an HF emission limit of 1.2 x 10<SUP>-2</SUP> lb/LT. For new 
indurating furnaces, we are finalizing an HCl emission limit of 4.4 x 
10<SUP>-4</SUP> lb/LT and are finalizing an HF emission limit of 3.3 x 
10<SUP>-4</SUP> lb/LT. Further discussion of the HCl and HF emission 
standards and the methodology used to develop the emission standards, 
as well as a discussion of costs, may be found in the memorandum, Final 
Revised Technology Review of Acid Gas Controls for Indurating Furnaces 
in the Taconite Iron Ore Processing Source Category, which is available 
in the docket for this action.
    We are also finalizing as proposed the requirement to complete 
performance testing for HCl and HF using EPA Method 26A and to 
establish operating limits for each control device used to comply with 
the HCl and HF standards, in accordance with the amended provisions of 
40 CFR 63.9622. The final rule clarifies that the owner or operator 
must perform performance testing when the pellet production rate is 
equal to or greater than 90 percent of the capacity of the indurating 
furnace. If the performance testing cannot be performed at or above 90 
percent of capacity of the indurating furnace, the owner or operator 
may complete testing at a lower production rate if they receive 
approval from the delegated authority. The owner or operator must 
install and operate CPMS in accordance with the requirements of 40 CFR 
63.9633 and must prepare a preventive maintenance plan and keep records 
of calibration and accuracy checks of the CPMS to document proper 
operation and maintenance of each monitoring system. An owner or 
operator must take corrective action when an established operating 
limit is exceeded. The owner or operator must complete the initial 
performance tests within 180 calendar days of the compliance date for 
existing furnaces, or within 180 calendar days of startup for new 
furnaces. The performance tests must be repeated at least twice per 5-
year permit term.

[[Page 16420]]

C. What other amendments are we finalizing?

1. Requirement To Complete Performance Testing Within 7 Calendar Days
    The EPA proposed amendments to the performance testing provisions 
that would require the owner or operator to complete a performance test 
on a source within 7 calendar days of initiating that performance test. 
This provision was included for the existing performance testing for 
PM, as well as for the proposed new performance testing for Hg, HCl, 
and HF. We received one comment that resulted in changes to the 
proposed requirements. The comment and our response are summarized 
below.
    Comments: Industry commenters opposed the proposed requirement that 
all performance testing be completed within 7 calendar days because 
some emission sources have multiple stacks and testing of multiple 
stacks could require more than 7 days to complete. They also stated 
that unanticipated shutdowns due to process upsets may prevent tests 
from being completed within 7 days. The commenters recommended that the 
EPA allow facilities to notify the Administrator when a longer time 
frame is needed but asserted that facilities should not be required to 
obtain approval if more than 7 calendar days are needed to complete 
performance testing.
    Response: We consider the 7 calendar day period to complete all 
performance testing to be reasonable based on our previous experience 
with performance testing at industrial facilities. We believe it is 
unlikely that a facility would be unable to complete the required 
performance testing within a 7 calendar day timeframe. However, we 
acknowledge the commenters' concerns that unanticipated shutdowns can 
occur due to equipment failures or process upsets. To address such 
circumstances, we included the phrase ``to the extent practicable'' in 
the final rule. We have finalized the proposed requirement that 
performance tests be completed within 7 calendar days of the date on 
which the first test run was started. However, we agree with the 
commenters' suggestion that owners and operators be required to notify 
the Administrator when a performance test cannot be completed within 7 
calendar days. In the final rule, we revised the proposed language in 
40 CFR 63.9620(b)(2), 63.9620(k)(2), and 63.9630(b) to require 
facilities that will not be able to complete performance tests within 7 
calendar days to notify the Administrator within 24 hours of making the 
determination that they will not be able to do so.
2. Amendments to the Electronic Reporting Requirements
    We are also finalizing as proposed changes to the electronic 
reporting requirements found in 40 CFR 63.9641(c) and 40 CFR 
63.9641(f)(3) to reflect new procedures for reporting CBI, including 
adding an email address that an owner or operator may use to 
electronically submit compliance reports containing CBI to the OAQPS 
CBI Office. We received no comments on these proposed amendments.

D. What are the effective and compliance dates for the mercury, HCl, 
and HF emission standards?

    The revisions to the MACT standards promulgated in this action are 
effective on March 6, 2024. For all affected sources that commence 
construction or reconstruction before May 15, 2023, we are finalizing, 
as proposed, that an owner or operator must comply with the new Hg 
emission standard and revised HCl and HF standards no later than 3 
years after the effective date of the final rule. For all affected 
sources that commenced construction or reconstruction on or after May 
15, 2023, we are finalizing, as proposed, that owners and operators 
comply with provisions by the effective date of the final rule or upon 
startup, whichever is later. For existing sources, CAA section 
112(i)(3) requires compliance ``as expeditiously as practicable, but in 
no event later than 3 years after the effective date of such standard'' 
subject to certain exemptions further detailed in the statute.\4\ In 
determining what compliance period is as ``expeditious as 
practicable,'' we examine the amount of time needed to plan and 
construct projects and change operating procedures. Since some existing 
sources may need to install new add-on controls to comply with the Hg, 
HCl, and/or HF standards, we determined that a period of 3 years is 
appropriate to allow owners and operators time to plan, design, 
construct, begin operating the new add-on controls, and conduct 
performance testing.
---------------------------------------------------------------------------

    \4\ Association of Battery Recyclers v. EPA, 716 F.3d 667, 672 
(D.C. Cir. 2013) (``Section 112(i)(3)'s 3-year maximum compliance 
period applies generally to any emission standard . . . promulgated 
under [section 112]'' (brackets in original)).
---------------------------------------------------------------------------

IV. Summary of Cost, Environmental, and Economic Impacts

A. What are the affected sources?

    The Taconite Iron Ore Processing NESHAP applies to the owner or 
operator of a taconite iron ore processing plant that is (or is part 
of) a major source of HAP emissions. A taconite iron ore processing 
plant is any facility engaged in separating and concentrating iron ore 
from taconite ore to produce taconite pellets. Taconite iron ore 
processing includes the following processes: liberation of the iron ore 
by wet or dry crushing and grinding in gyratory crushers, cone 
crushers, rod mills, and ball mills; concentration of the iron ore by 
magnetic separation or flotation; pelletizing by wet tumbling with a 
balling drum or balling disc; induration using a straight grate or 
grate kiln indurating furnace; and finished pellet handling. A major 
source of HAP is a plant site that emits, or has the potential to emit, 
any single HAP at a rate of 9.07 megagrams (10 tons) or more, or any 
combination of HAP at a rate of 22.68 megagrams (25 tons) or more per 
year from all emission sources at the plant site. There are currently 
seven major sources subject to the Taconite Iron Ore Processing NESHAP 
that are operating in the United States with six located in Minnesota 
and one located in Michigan. One additional major source located in 
Michigan, Empire Mining, is subject to the Taconite Iron Ore Processing 
NESHAP and has a permit to operate but has been indefinitely idled 
since 2016.

B. What are the air quality impacts?

    To meet the Hg emission limits we anticipate that five of the 
taconite iron ore processing plants would likely need to install 
additional controls on their indurating furnaces. To meet the HCl and 
HF emission limits, we anticipate that one additional taconite iron ore 
processing plant would likely need to install additional controls on 
their indurating furnaces. We estimate that the installation of such 
controls will reduce Hg emissions by 247 pounds per year (0.12 tpy) and 
HCl and HF emissions by 683 tpy and 36 tpy, respectively.
    Indirect or secondary air emissions impacts are impacts that would 
result from the increased electricity usage associated with the 
operation of control devices (e.g., increased secondary emissions of 
criteria pollutants from power plants). Energy impacts consist of the 
electricity and steam needed to operate control devices and other 
equipment. As explained in the memorandum, Development of Impacts for 
the Final Amendments to the NESHAP for Taconite Iron Ore Processing, 
which is available in the docket for this action, we find that the 
secondary air emissions impacts of this

[[Page 16421]]

action are minimal. The memorandum includes a detailed discussion of 
our analysis of emissions reductions and potential secondary impacts.
    This rule is expected to limit emissions of directly emitted 
PM<INF>2.5</INF>, which will in turn reduce ambient concentrations of 
PM<INF>2.5</INF> and in turn benefit public health. Though EPA neither 
quantified nor monetized these benefits, we anticipate reducing 
PM<INF>2.5</INF> concentrations will reduce the incidence or premature 
death, non-fatal heart attacks, cases of aggravated asthma, lost days 
of work and school and other adverse effects (U.S. EPA, 2022).\5\ EPA 
has generated benefit per ton estimates for directly emitted 
PM<INF>2.5</INF> reductions from the taconite sector valued at $60,600/
ton (2016$).\6\ In addition, there are estimates for secondarily-formed 
PM<INF>2.5</INF> from reductions in SO<INF>2</INF> emissions valued at 
$32,800/ton (2016$). However, EPA did not conduct a comprehensive 
benefit-cost analysis for this rulemaking. This rule is also expected 
to reduce emissions of Hg. Methylmercury (MeHg), which is formed by 
microbial action in the top layers of sediment and soils, after mercury 
has precipitated from the air and deposited into waterbodies or land, 
is known to cause a number of adverse effects. Though not quantified 
here, these effects include IQ loss measured by performance on 
neurobehavioral tests, particularly on tests of attention, fine motor-
function, language, and visual spatial ability.
---------------------------------------------------------------------------

    \5\ U.S. EPA, 2022. Estimating PM<INF>2.5</INF>- and Ozone-
Attributable Health Benefits. Office of Air and Radiation, Research 
Triangle Park, NC.
    \6\ U.S. EPA (2023). Technical Support Document Estimating the 
Benefit per Ton of Reducing Directly-Emitted PM<INF>2.5</INF>, 
PM<INF>2.5</INF> Precursors and Ozone Precursors from 21 Sectors. 
Research Triangle Park, NC: U.S. Environmental Protection Agency, 
Office of Air Quality Planning and Standards, Health and 
Environmental Impact Division. Available at: https://www.epa.gov/system/files/documents/2021-10/source-apportionment-tsd-oct-222021_0.pdf.
---------------------------------------------------------------------------

C. What are the cost impacts?

    We estimate the total capital and annualized costs of this final 
rule for existing sources in the Taconite Iron Ore Processing source 
category will be approximately $106 million and $68 million per year, 
respectively. The annual costs are based on operation and maintenance 
of added control systems. Although this action also finalizes standards 
for new sources, we are not aware of any new sources being constructed 
now or planned for the future. No new indurating furnaces have been 
constructed, reconstructed or modified in more than a decade and the 
domestic demand for taconite pellets has decreased over the past 
several decades caused by the increasing use of electric arc 
furnaces.\7\ Consequently, we did not estimate any cost impacts for new 
sources. The memorandum, Development of Impacts for the Final 
Amendments to the NESHAP for Taconite Iron Ore Processing, includes 
details of our cost assessment, expected emission reductions and 
estimated secondary impacts. A copy of this memorandum is available in 
the docket for this action.
---------------------------------------------------------------------------

    \7\ U.S. EPA, 2024. Economic Impact Analysis for the Final 
National Emission Standards for Hazardous Air Pollutants: Taconite 
Iron Ore Processing Amendments. Office of Air and Radiation, 
Research Triangle Park, NC.
---------------------------------------------------------------------------

D. What are the economic impacts?

    The EPA assessed the potential economic impacts of this action by 
comparing the expected annual cost for operating the air pollution 
control devices to the total sales revenue for the ultimate owners of 
affected facilities. The expected annual cost is $10.2 million (on 
average) for each facility that needs air pollution controls to comply 
with the standards, with an estimated nationwide annual cost of $61 
million per year. The six affected facilities are owned by two parent 
companies (U.S. Steel and Cleveland-Cliffs, Inc.). Neither parent 
company qualifies as a small business, and the total costs associated 
with this final rule are expected to be less than 1 percent of annual 
sales revenue per ultimate owner.
    The EPA also modeled the economic impacts of the final rule using 
two standard partial equilibrium economic models: one for taconite iron 
ore pellets and one for steel mill products. The EPA linked these two 
partial equilibrium models by specifying interactions between supply 
and demand in both markets and solving for changes in prices and 
quantity across both markets simultaneously. These models use baseline 
economic data from 2019 to project the impact of the final rule on the 
market for taconite iron ore pellets and steel mill products. The 
models allow the EPA to project facility- and market-level price and 
quantity changes for taconite iron ore pellets and market-level price 
and quantity changes for steel mill products, including changes in 
imports and exports in both markets. The models project a 0.28 percent 
fall in the quantity of domestically produced taconite iron ore pellets 
along with a 0.63 percent increase in their price. The models also 
project a 0.02 percent fall in the quantity of domestically produced 
steel mill products along with an 0.01 percent increase in their price. 
Details of our economic impact estimates for sources in the Taconite 
Iron Ore Processing source category may be found in the document, 
Economic Impact Analysis for the Final National Emission Standards for 
Hazardous Air Pollutants: Taconite Iron Ore Processing Amendments 
(EIA), which is available in the docket for this action.

E. What analysis of environmental justice did we conduct?

    Consistent with the EPA's commitment to integrating environmental 
justice (EJ) into the Agency's actions, and following the directives 
set forth in multiple executive orders, the EPA evaluated the impacts 
of this action on communities with EJ concerns. Overall, we found that 
in the population living in close proximity (within 10 kilometers (km)) 
of facilities, the following demographic groups were above the national 
average: White, Native American, and people living below the poverty 
level. The EPA defines EJ as ``the fair treatment and meaningful 
involvement of all people regardless of race, color, national origin, 
or income, with respect to the development, implementation, and 
enforcement of environmental laws, regulations, and policies.'' \8\ The 
EPA further defines fair treatment to mean that ``no group of people 
should bear a disproportionate burden of environmental harms and risks, 
including those resulting from the negative environmental consequences 
of industrial, governmental, and commercial operations or programs and 
policies.''
---------------------------------------------------------------------------

    \8\ https://www.epa.gov/environmentaljustice.
---------------------------------------------------------------------------

    For the Taconite Iron Ore Processing source category, the EPA 
examined the potential for EJ concerns by conducting a proximity 
demographic analysis for the eight existing taconite iron ore 
processing plants (seven operating plants and one indefinitely idled). 
The proximity demographic analysis is an assessment of individual 
demographic groups in the total population living within 10 km and 50 
km of the facilities. The EPA compared the data from this analysis to 
the national average for each of the demographic groups. Since the 
taconite iron ore processing facilities are very large, a radius of 10 
km was used as the near facility distance for the proximity analysis. A 
distance closer than 10 km does not yield adequate population size for 
the results. A summary of the proximity demographic assessment was 
included in Table 5 in the proposal for this rulemaking (88 FR 30931; 
May 15, 2023). The results show that for the population living within 
10

[[Page 16422]]

km of the eight facilities, the following demographic groups were above 
the national average: White (93 percent versus 60 percent nationally), 
Native American (0.8 percent versus 0.7 percent nationally), and people 
living below the poverty level (15 percent versus 13 percent 
nationally). For two facilities (the UTAC and Minntac facilities), the 
percentage of the population living within 10 km that is Native 
American (1.9 percent and 2.3 percent) was more than double the 
national average (0.7 percent). For four facilities (Keetac, Hibbing, 
Minorca, and Minntac) the percentage of the population living within 10 
km that is low-income is above the national average. The results of the 
proximity analysis are in the technical report, Analysis of Demographic 
Factors For Populations Living Near Taconite Iron Ore Processing Source 
Category Operations, which is available in the docket for this action.
    This action sets new standards for Hg and revised standards for HCl 
and HF that will reduce the annual emissions of these HAP from taconite 
facilities. The Hg standards will reduce the health, environmental and 
cultural impacts of Hg identified by tribes in their comments by 
requiring the five taconite facilities (UTAC, Keetac, Hibbing, Minorca, 
and Minntac) that have nearby Native American populations and low-
income populations above the national averages to reduce Hg emissions 
by up to 247 pounds per year (0.12 tpy). The emission limits must be 
met at all times (including periods of startup, shutdown, and 
malfunctions) and compliance must be demonstrated through monitoring of 
control device operating parameters and either periodic testing or 
CEMS.

V. Statutory and Executive Order Reviews

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

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

    This action is a ``significant regulatory action'' 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 is 
summarized in section IV.D of this preamble and in the document 
Economic Impact Analysis for the Final National Emission Standards for 
Hazardous Air Pollutants: Taconite Iron Ore Processing Amendments, 
available in Docket ID No. EPA-HQ-OAR-2017-0664.

B. Paperwork Reduction Act (PRA)

    The information collection activities in this rule have been 
submitted for approval to the OMB under the PRA. The ICR document that 
the EPA prepared has been assigned EPA ICR number 2050.10, OMB Control 
Number 2060-0538. 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 changes to the reporting and 
recordkeeping requirements for the Taconite Iron Ore Processing NESHAP 
by incorporating reporting and recordkeeping requirements for the new 
MACT standards for Hg and the revised emission standards for HCl and 
HF.
    Respondents/affected entities: Owners or operators of taconite iron 
ore plants that are major sources, or that are located at, or are part 
of, major sources of HAP emissions.
    Respondent's obligation to respond: Mandatory (40 CFR part 63, 
subpart RRRRR).
    Estimated number of respondents: On average over the next 3 years, 
approximately seven existing major sources will be subject to these 
standards. It is also estimated that no additional respondent will 
become subject to the emission standards over the 3-year period.
    Frequency of response: The frequency of responses varies depending 
on the burden item.
    Total estimated burden: The average annual burden to industry over 
the next 3 years from the new recordkeeping and reporting requirements 
is estimated to be 1,580 hours per year. Burden is defined at 5 CFR 
1320.3(b).
    Total estimated cost: The annual recordkeeping and reporting costs 
for all facilities to comply with all the requirements in the NESHAP is 
estimated to be $185,000 per year. The average annual recordkeeping and 
reporting cost for this rulemaking is estimated to be $26,500 per 
facility per year. The operation and maintenance costs are estimated to 
be $18 million per year.
    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. The Agency 
confirmed through responses to a CAA section 114 information request 
that there are only seven taconite iron ore processing plants currently 
operating in the United States and that these plants are owned by two 
parent companies that do not meet the definition of small businesses, 
as defined by the U.S. Small Business Administration.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain an unfunded mandate of $100 million or 
more as described in UMRA, 2 U.S.C. 1531-1538, and does not 
significantly or uniquely affect small governments. This action imposes 
no enforceable duty on any state, local, or Tribal governments or the 
private sector.

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.'' The amendments in this 
action would 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

[[Page 16423]]

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 
Consultation and Coordination with Indian Tribes, the EPA consulted 
with Tribal officials during the development of this action. On January 
12, 2022, the EPA's Office of Air and Radiation held a Tribal 
consultation meeting with the Fond du Lac Band of Lake Superior 
Chippewa Reservation and the Leech Lake Band of Ojibwe Reservation to 
discuss the EPA's 2022 CAA section 114 information request and to 
ensure that the views of tribes were taken into consideration in the 
rulemaking process in accordance with the EPA Policy on Consultation 
and Coordination with Indian Tribes (May 4, 2011) and the EPA Policy on 
Consultation and Coordination with Indian Tribes: Guidance for 
Discussing Tribal Treaty Rights (February 2016). A summary of the 
meeting may be found in the document, Consultation with the Fond du Lac 
Band of Lake Superior Chippewa and the Leech Lake Band of Ojibwe 
regarding Notice of Proposed Rulemaking for the National Emission 
Standards for Hazardous Air Pollutants for Taconite Iron Ore Processing 
Amendments on January 12, 2022, which is available in the docket for 
this action. In addition, the EPA's staff attended several meetings 
hosted by the Minnesota Pollution Control Agency (MPCA), along with 
representatives from Tribal Nations, MPCA, the Michigan Attorney 
General's Office, the Minnesota Attorney General's Office, 
Earthjustice, and the Michigan Department of Environment, Great Lakes, 
and Energy, to discuss concerns related to HAP emissions from taconite 
iron ore processing facilities. The EPA also received letters from 
representatives of the Leech Lake Band of Ojibwe and the Fond du Lac 
Band of Lake Superior Chippewa expressing concerns of these Tribal 
Nations due to HAP emissions from the taconite iron ore processing 
facilities. Copies of these letters, as well as the EPA's responses to 
them, are available in the docket for this action.

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

    This action involves technical standards. Therefore, the EPA 
conducted searches for the Taconite Iron Ore Processing NESHAP through 
the Enhanced National Standards Systems Network (NSSN) Database managed 
by the American National Standards Institute (ANSI). We also conducted 
a review of VCS organizations and accessed and searched their 
databases. We conducted searches for EPA Methods 1, 1A, 2, 2A, 2C, 2D, 
2F, 2G, 3, 3A, 3B, 4, 5, 5D, 17, 26A, 29 and 30B. During the VCS 
search, if the title or abstract (if provided) of the VCS described 
technical sampling and analytical procedures that are similar to the 
EPA's reference method, the EPA ordered a copy of the standard and 
reviewed it as a potential equivalent method. We reviewed all potential 
standards to determine the practicality of the VCS for this rule. This 
review requires significant method validation data that meet the 
requirements of EPA Method 301 for accepting alternative methods or 
scientific, engineering, and policy equivalence to procedures in the 
EPA referenced methods. The EPA may reconsider determinations of 
impracticality when additional information is available for any 
particular VCS.
    No VCS were identified for EPA Methods 1, 1A, 2, 2A, 2C, 2D, 2F, 
2G, 3, 3A, 4, 5, 5D, 17 or 26A. One VCS was identified as an acceptable 
alternative to EPA Methods 3B, 29 and 30B.
    The EPA is allowing use of the VCS 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)'' as an acceptable alternative to EPA Method 29 (Hg portion 
only) as a method for measuring Hg concentrations ranging from 
approximately 0.5 to 100 micrograms per normal cubic meter ([micro]g/
Nm\3\). 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. VCS ASTM D6784-16 allows for additional flexibility in the 
sampling and analytical procedures from the earlier version of the same 
standard VCS ASTM D6784-02 (Reapproved 2008). VCS ASTM D6784-16 allows 
for the use of either an EPA Method 17 sampling configuration with a 
fixed (single) point where the flue gas is not stratified, or an EPA 
Method 5 sampling configuration with a multi-point traverse. For this 
action, only the EPA Method 5 sampling configuration with a multi-point 
traverse can be used. This method is available at ASTM International, 
100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959. 
See https://www.astm.org/. The standard is available to everyone at a 
cost determined by ASTM ($82). The cost of obtaining this method is not 
a significant financial burden, making the method reasonably available. 
Additional detailed information on the VCS search and determination can 
be found in the memorandum, Voluntary Consensus Standard Results for 
National Emission Standards for Hazardous Air Pollutants: Taconite Iron 
Ore Processing, which is available in the docket for this action. The 
EPA solicited comment on potentially applicable VCS in the proposal for 
this rule. However, no other VCS were identified. The EPA is finalizing 
as proposed incorporating by reference the VCS 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),'' as an acceptable alternative to EPA Method 29 
(Hg portion only).

H. 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 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 EJ concerns. The assessment of populations 
in close proximity of taconite iron ore processing plants shows Native 
American and low-income populations are higher than the national 
average (see section IV.E of this preamble). The higher percentages of 
Native American populations are near the UTAC and Minntac facilities. 
The higher percentages of low-income populations are near the Keetac, 
Hibbing, Minorca, and Minntac facilities. The EPA believes that this 
action is likely to reduce existing disproportionate and adverse 
effects on low-income populations and/or indigenous peoples. The EPA is 
finalizing new MACT standards for Hg and revised standards for HCl and 
HF. The EPA expects that at least five facilities would have to 
implement control measures to reduce Hg emissions to comply with the 
new Hg MACT standard (including the UTAC, Keetac, Hibbing, Minorca and 
Minntac facilities) and one facility would need to implement control 
measures to reduce HCl emissions to comply with the revised standard 
for HCl (the Tilden facility). HAP exposures for indigenous peoples and 
low-income individuals

[[Page 16424]]

living near these six facilities would decrease. The methodology and 
the results of the demographic analysis are available in the docket for 
this action in the technical report Analysis of Demographic Factors For 
Populations Living Near Taconite Iron Ore Processing Source Category 
Operations.

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

    Executive Order 13045 (62 FR 19885; April 23, 1997) directs Federal 
agencies to include an evaluation of the health and safety effects of 
the planned regulation on children in Federal health and safety 
standards and explain why the regulation is preferable to potentially 
effective and reasonably feasible alternatives. This action is not 
subject to Executive Order 13045 because it is not significant as 
defined in Executive Order 12866(3)(f)(1), and because the EPA does not 
believe the environmental health or safety risks addressed by this 
action present a disproportionate risk to children. In 2020, the EPA 
conducted a residual risk assessment and determined that risk from the 
Taconite Iron Ore Processing source category was acceptable, and the 
standards provided an ample margin of safety to protect public health 
(see 85 FR 45476 and Docket ID No. EPA-HQ-OAR-2017-0664-0163). For this 
rulemaking, we updated that risk analysis using new emissions data that 
the EPA received for some HAP emissions sources at the taconite 
facilities. We determined that these new HAP emissions estimates would 
not significantly change our previous estimates of the human health 
risk posed by the Taconite Iron Ore Processing source category. In this 
action the EPA is promulgating new emission standards for one 
previously unregulated pollutant (Hg) and revised emissions standards 
for two currently regulated pollutants (HCl and HF). These emissions 
standards will reduce Hg, HCl and HF emissions and thereby reduce 
children's exposure to these harmful HAP. We estimate that the 
installation of controls will reduce HCl and HF emissions by 683 tpy 
and 36 tpy, respectively, and will reduce Hg emissions by up to 247 
pounds per year (0.12 tpy).
    This action's health and risk assessments are protective of the 
most vulnerable populations, including children, due to how we 
determine exposure and through the health benchmarks that we use. 
Specifically, the risk assessments we perform assume a lifetime of 
exposure, in which populations are conservatively presumed to be 
exposed to airborne concentrations at their residence continuously, 24 
hours per day for a 70-year lifetime, including childhood. With regards 
to children's potentially greater susceptibility to noncancer 
toxicants, the assessments rely on the EPA's (or comparable) hazard 
identification and dose-response values that have been developed to be 
protective for all subgroups of the general population, including 
children. For more information on the risk assessment methods, see the 
risk report for the July 28, 2020, final Taconite residual risk and 
technology review (RTR) rule (85 FR 45476), which is available in the 
docket. Therefore, the rulemaking finalizes actions that will result in 
health benefits to children by reducing the level of HAP emissions 
emitted from taconite iron ore processing plants.

J. 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.

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, air pollution control, hazardous 
substances, incorporation by reference, mercury, hydrogen chloride, 
hydrogen fluoride, 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. Section 63.14 is amended by revising paragraph (i)(104) to read as 
follows:


Sec.  63.14  Incorporation by reference

* * * * *
    (i) * * *
    (104) 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.  63.9621(d); table 5 to subpart UUUUU; appendix 
A to subpart UUUUU.

Subpart RRRRR--National Emission Standards for Hazardous Air 
Pollutants: Taconite Iron Ore Processing

0
3. Section 63.9583 is revised and republished to read as follows:


Sec.  63.9583  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, and operation and 
maintenance requirement in this subpart that applies to you no later 
than October 30, 2006, except as specified in paragraph (f) of this 
section.
    (b) If you have a new affected source and its initial startup date 
is on or before October 30, 2003, you must comply with each emission 
limitation, work practice standard, and operation and maintenance 
requirement in this subpart that applies to you by October 30, 2003, 
except as specified in paragraph (f) of this section.
    (c) If you have a new affected source and its initial startup date 
is after October 30, 2003, you must comply with each emission 
limitation, work practice standard, and operation and maintenance 
requirement in this subpart that applies to you upon initial startup, 
except as specified in paragraph (f) of this section.
    (d) If your taconite iron ore processing plant is an area source 
that becomes a major source of HAP, the compliance dates in paragraphs 
(d)(1) and (2) of this section apply to you.
    (1) Any portion of the taconite iron ore processing plant 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 taconite iron ore processing plant must 
be in compliance with this subpart no later than 3 years after the 
plant becomes a major source.

[[Page 16425]]

    (e) You must meet the notification and schedule requirements in 
Sec.  63.9640. Several of these notifications must be submitted before 
the compliance date for your affected source.
    (f) If you have an affected indurating furnace that commenced 
construction before May 15, 2023, you must comply with the requirements 
in paragraphs (f)(1) through (7) of this section by March 8, 2027. If 
you have an affected indurating furnace that commenced construction or 
reconstruction on or after May 15, 2023, you must comply with the 
requirements in paragraphs (f)(1) through (7) of this section by March 
6, 2024 or the date of initial startup, whichever is later.
    (1) All applicable emission limits for mercury, hydrogen chloride, 
and hydrogen fluoride in tables 2 and 3 to this subpart.
    (2) All applicable operating limits in Sec.  63.9590(b)(5) through 
(8), established in accordance with Sec.  63.9622(g) through (i), for 
each control device used to comply with the mercury, hydrogen chloride, 
and hydrogen fluoride emission limits.
    (3) All applicable compliance requirements in Sec. Sec.  63.9600, 
63.9610, 63.9623, 63.9625, and 63.9637(a).
    (4) The applicable performance testing or continuous emissions 
monitoring system (CEMS) requirements for mercury in Sec. Sec.  
63.9620(k), 63.9621(d), and 63.9630.
    (5) All applicable performance testing requirements in Sec. Sec.  
63.9620(l), 63.9621(d), and 63.9630.
    (6) The requirements to install and maintain monitoring equipment 
in Sec.  63.6332(g) through (i) and the monitoring requirements in 
Sec. Sec.  63.9631, 63.9633, and 63.9634 for each control device used 
to comply with the mercury, hydrogen chloride and hydrogen fluoride 
emission limits.
    (7) The notification, reporting and recordkeeping requirements in 
Sec. Sec.  63.9640, 63.9641, 63.9642, and 63.9643 applicable to the 
mercury, hydrogen chloride, and hydrogen fluoride emission standards.

0
4. Section 63.9590 is revised and republished to read as follows:


Sec.  63.9590  What emission limitations and operating limits must I 
meet?

    (a) You must meet each emission limit in tables 1 through 3 to this 
subpart that applies to you by the applicable compliance date specified 
in Sec.  63.9583.
    (b) You must meet each applicable operating limit for control 
devices in paragraphs (b)(1) through (8) of this section that applies 
to you by the applicable compliance date specified in Sec.  63.9583. 
You are not required to establish and comply with operating limits for 
control devices used to reduce mercury emissions when you are using a 
CEMS to monitor and demonstrate compliance with the mercury emission 
limit in table 2 to this subpart.
    (1) Except as provided in paragraph (b)(2) of this section, for 
each wet scrubber applied to meet any particulate matter emission limit 
in table 1 to this subpart, you must maintain the daily average 
pressure drop and daily average scrubber water flow rate at or above 
the minimum levels established in Sec.  63.9622.
    (2) On or before January 28, 2022, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, for each dynamic wet scrubber applied to meet any particulate 
matter emission limit in table 1 to this subpart, you must maintain the 
daily average scrubber water flow rate and either the daily average fan 
amperage (a surrogate for fan speed as revolutions per minute) or the 
daily average pressure drop at or above the minimum levels established 
during the initial performance test. After January 28, 2022, for 
affected sources that commenced construction or reconstruction on or 
before September 25, 2019, and after July 28, 2020, or upon start-up, 
which ever date is later, for affected sources that commenced 
construction or reconstruction after September 25, 2019, for each 
dynamic wet scrubber applied to meet any particulate matter emission 
limit in table 1 to this subpart, you must maintain the daily average 
scrubber water flow rate and the daily average fan amperage (a 
surrogate for fan speed as revolutions per minute) at or above the 
minimum levels established in Sec.  63.9622.
    (3) For each dry electrostatic precipitator (ESP) applied to meet 
any particulate matter emission limit in Table 1 to this subpart, you 
must meet the operating limits in paragraph (b)(3)(i) or (ii) of this 
section.
    (i) Maintain the 6-minute average opacity of emissions exiting the 
control device stack at or below the level established during the 
initial performance test.
    (ii) Maintain the daily average secondary voltage and daily average 
secondary current for each field at or above the minimum levels 
established during the initial performance test.
    (4) For each wet ESP applied to meet any particulate matter 
emission limit in table 1 to this subpart, you must meet the operating 
limits in paragraphs (b)(4)(i) through (iii) of this section.
    (i) Maintain the daily average secondary voltage for each field at 
or above the minimum levels established during the initial performance 
test.
    (ii) Maintain the daily average stack outlet temperature at or 
below the maximum levels established during the initial performance 
test.
    (iii) Maintain the daily average water flow rate at or above the 
minimum levels established during the initial performance test.
    (5) For each wet scrubber and wet ESP used to meet the hydrogen 
chloride and hydrogen fluoride emission limits in table 3 to this 
subpart, you must maintain the daily average scrubber water flow rate 
and pH greater than or equal to the operating limits established for 
these parameters established in Sec.  63.9622.
    (6) For each activated carbon injection (ACI) system used to meet 
the mercury emission limit in table 2 to this subpart, you must 
maintain the daily average activated carbon injection rate greater than 
or equal to the average activated carbon injection rate established 
during the most recent performance test demonstrating compliance with 
the applicable emission limit. In addition, you must maintain the daily 
average carrier gas flow rate greater than or equal to the average 
carrier gas flow rate established during the most recent performance 
test demonstrating compliance with the applicable emission limit.
    (7) For each dry sorbent injection (DSI) system used to meet the 
hydrogen chloride and hydrogen fluoride emission limits in table 3 to 
this subpart, you must maintain the daily average dry sorbent injection 
rate greater than or equal to the average dry sorbent injection rate 
established during the most recent performance test. demonstrating 
compliance with the applicable emission limit. In addition, you must 
maintain the daily average carrier gas flow rate greater than or equal 
to the average carrier gas flow rate established during the most recent 
performance test demonstrating compliance with the applicable emission 
limit.
    (8) If you use any air pollution control device other than a 
baghouse, wet scrubber, dynamic scrubber, dry ESP, wet ESP, ACI, or 
DSI, you must submit a site-specific monitoring plan in accordance with 
Sec.  63.9631(f).
    (c) You may petition the Administrator for approval of alternatives 
to the monitoring requirements in paragraphs (b)(1) through (7) of this 
section as allowed under Sec.  63.8(f) and as defined in Sec.  63.90.

0
5. Section 63.9600 is amended by revising paragraph (b) introductory 
text to read as follows:

[[Page 16426]]

Sec.  63.9600  What are my operation and maintenance requirements?

* * * * *
    (b) You must prepare, and at all times, operate according to, a 
written operation and maintenance plan for each control device applied 
to meet any particulate matter emission limit in table 1 to this 
subpart, mercury emission limit in table 2 to this subpart, hydrogen 
chloride and hydrogen fluoride emission limit in table 3 to this 
subpart, and to meet the requirement of each indurating furnace subject 
to good combustion practices (GCP). Each site-specific operation and 
maintenance plan must be submitted to the Administrator on or before 
the compliance date that is specified in Sec.  63.9583 for your 
affected source. The plan you submit must explain why the chosen 
practices (i.e., quantified objectives) are effective in performing 
corrective actions or GCP in minimizing the formation of formaldehyde 
(and other products of incomplete combustion). The Administrator will 
review the adequacy of the site-specific practices and objectives you 
will follow and the records you will keep to demonstrate compliance 
with your Plan. If the Administrator determines that any portion of 
your operation and maintenance plan is not adequate, we can reject 
those portions of the plan, and request that you provide additional 
information addressing the relevant issues. In the interim of this 
process, you will continue to follow your current site-specific 
practices and objectives, as submitted, until your revisions are 
accepted as adequate by the Administrator. You must maintain a current 
copy of the operation and maintenance plan onsite, and it must be 
available for inspection upon request. You must keep the plan for the 
life of the affected source or until the affected source is no longer 
subject to the requirements of this subpart. Each operation and 
maintenance plan must address the elements in paragraphs (b)(1) through 
(4) of this section.
* * * * *

0
6. Section 63.9610 is amended by revising paragraph (a) introductory 
text and adding paragraph (d) to read as follows:


Sec.  63.9610  What are my general requirements for complying with this 
subpart?

    (a) On or before January 25, 2021, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, you must be in compliance with the requirements in paragraphs 
(a)(1) through (6) of this section at all times, except during periods 
of startup, shutdown, and malfunction. After January 25, 2021, for 
affected sources that commenced construction or reconstruction on or 
before September 25, 2019, and after July 28, 2020, for affected 
sources that commenced construction or reconstruction after September 
25, 2019, you must be in compliance with the emission limitations, 
standards, and operation and maintenance requirements for the 
particulate matter emission standards in this subpart at all times.
* * * * *
    (d) On and after the applicable compliance date specified in Sec.  
63.9583(f), you must be in compliance with all applicable emission 
limitations for mercury, hydrogen chloride and hydrogen fluoride in 
tables 2 and 3 to this subpart and with the requirements in paragraphs 
(d)(1) through (6) of this section at all times.
    (1) All applicable operating limits in Sec.  63.9590(b)(5) through 
(8).
    (2) All applicable operation and maintenance requirements in Sec.  
63.9600 for control devices and monitoring equipment used to comply 
with the emissions limits.
    (3) The requirements in Sec.  63.9631(j), if you use emissions 
averaging to demonstrate compliance with the mercury standards.
    (4) The requirements in Sec.  63.9631(k), if you use continuous 
emissions monitoring system(s) (CEMS) to demonstrate compliance with 
the mercury standards.
    (5) The requirements in Sec.  63.9634(n), if you elect to adjust 
the activated carbon injection rate based on the taconite pellet 
production rate.
    (6) The notification, reporting and recordkeeping requirements in 
Sec. Sec.  63.9640 through 63.9643.

0
7. Section 63.9620 is amended by:
0
a. Revising paragraphs (b)(2) and (f)(2); and
0
b. Adding paragraphs (k) and (l).
    The revisions and addition read as follows:


Sec.  63.9620  On which units and by what date must I conduct 
performance tests or other initial compliance demonstrations?

* * * * *
    (b) * * *
    (2) Initial performance tests must be completed no later than 180 
calendar days after the compliance date specified in Sec.  63.9583. 
Performance tests conducted between October 30, 2003, and no later than 
180 days after the corresponding compliance date can be used for 
initial compliance demonstration, provided the tests meet the initial 
performance testing requirements of this subpart. For an indurating 
furnace with multiple stacks, the performance tests for all stacks must 
be completed within 7 calendar days of commencement of the performance 
tests, to the extent practicable, and the indurating furnace and 
associated control device (where applicable) operating characteristics 
must remain representative and consistent for the duration of the stack 
tests. If you determine that the performance tests cannot be completed 
within 7 calendar days, the Administrator must be notified within 24 
hours of making that determination.
* * * * *
    (f) * * *
    (2) All emission units within a group must also have the same type 
of air pollution control device (e.g., wet scrubbers, dynamic wet 
scrubbers, rotoclones, multiclones, wet and dry ESP, and baghouses). 
You cannot group emission units with different air pollution control 
device types together for the purposes of this section.
* * * * *
    (k) For each indurating furnace, you must demonstrate initial 
compliance with the mercury emission limits in table 2 to this subpart 
in accordance with the procedures specified in either paragraph (k)(1) 
or (2) of this section.
    (1) Complete an initial performance test on all stacks associated 
with each indurating furnace no later than 180 calendar days after the 
compliance date specified in Sec.  63.9583(f). Performance tests 
conducted between March 6, 2024 and 180 days after the corresponding 
compliance date can be used for initial compliance demonstration, 
provided the tests meet the initial performance testing requirements of 
this subpart. For an indurating furnace with multiple stacks, the 
performance tests for all stacks must be completed within 7 calendar 
days of commencement of the performance tests, to the extent 
practicable, and the indurating furnace and associated control device 
(where applicable) operating characteristics must remain representative 
and consistent for the duration of the stack tests. If you determine 
that the performance tests cannot be completed within 7 calendar days, 
the Administrator must be notified within 24 hours of making that 
determination.
    (2) You may use a 30-day rolling average of the 1-hour arithmetic 
average CEMS data. You must conduct a performance evaluation of each 
CEMS within 180 days of installation of the monitoring system. The 
initial performance evaluation must be conducted prior to collecting 
CEMS data

[[Page 16427]]

that will be used for the initial compliance demonstration.
    (l) For each indurating furnace, you must demonstrate initial 
compliance with the emission limits in table 3 to this subpart by 
conducting initial performance tests for hydrogen chloride and hydrogen 
fluoride on all stacks associated with each indurating furnace. Initial 
performance tests must be completed no later than 180 calendar days 
after the compliance date specified in Sec.  63.9583(f). Performance 
tests conducted between March 6, 2024 and 180 days after the 
corresponding compliance date can be used for initial compliance 
demonstration, provided the tests meet the initial performance testing 
requirements of this subpart. For an indurating furnace with multiple 
stacks, the performance tests for all stacks must be completed within 7 
calendar days of commencement of the performance tests, to the extent 
practicable, and the indurating furnace and associated control device 
(where applicable) operating characteristics must remain representative 
and consistent for the duration of the stack tests. If you determine 
that the performance tests cannot be conducted within 7 calendar days, 
the Administrator must be notified within 24 hours of making that 
determination.

0
8. Section 63.9621 is amended by:
0
a. Revising the section heading;
0
b. Revising paragraphs (a) and (c) introductory text; and
0
c. Adding paragraphs (d) and (e).
    The revisions and additions read as follows:


Sec.  63.9621  What test methods and other procedures must I use to 
demonstrate initial compliance with the emission limits?

    (a) On or before January 25, 2021, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, you must conduct each performance test that applies to your 
affected source according to the requirements in Sec.  63.7(e)(1) and 
paragraphs (b) and (c) of this section. After January 25, 2021, for 
affected sources that commenced construction or reconstruction on or 
before September 25, 2019, and after July 28, 2020, or upon start-up, 
which ever date is later, for affected sources that commenced 
construction or reconstruction after September 25, 2019, you must 
conduct each performance test that applies to your affected source, 
including the initial performance tests for mercury required in Sec.  
63.9620(k)(1) and the initial performance tests for hydrogen chloride 
and hydrogen fluoride required in Sec.  63.9620(l), 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 normal 
operation. Upon request, the owner or operator shall make available to 
the Administrator such records as may be necessary to determine the 
conditions of performance tests. You must also conduct each performance 
test that applies to your affected source according to the requirements 
in paragraphs (b) and (c) of this section.
* * * * *
    (c) For each ore dryer affected source and each indurating furnace 
affected source, you must determine compliance with the applicable 
emission limit for particulate matter in table 1 to this subpart by 
following the test methods and procedures in paragraphs (c)(1) through 
(2) of this section.
* * * * *
    (d) For each indurating furnace subject to the initial performance 
testing under Sec.  63.9620(k)(1) or (l), you must determine compliance 
with the applicable emission limits for mercury, hydrogen chloride and 
hydrogen fluoride in tables 2 and 3 to this subpart by following the 
test methods and procedures in paragraphs (d)(1) through (9) of this 
section. You are not required to complete the initial performance test 
for mercury emissions when you are using a CEMS in accordance with 
paragraph (e) of this section.
    (1) The furnace must be operated at or above 90 percent of capacity 
throughout the duration of the performance testing. If testing cannot 
be performed at or above 90 percent of capacity, you must provide an 
explanation for the lower production rate in your performance test 
plan. The lower production rate must be approved by the Administrator 
prior to beginning performance testing. For indurating furnaces that 
comply with the mercury emissions limit in table 2 to this subpart by 
adjusting the activated carbon injection rate based on the taconite 
pellet production rate, you must complete the performance testing for 
mercury in accordance with the provisions in Sec.  63.9634(n).
    (2) Use the methods specified in paragraphs (c)(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.
    (3) Determine the concentration of mercury for each stack using 
Method 29 or Method 30B in 40 CFR part 60, appendix A, or the voluntary 
consensus standard ASTM D6784-16 (incorporated by reference, see Sec.  
63.14). For Method 29 and ASTM D6784-16, the sample volume must be at 
least 1.7 dry standard cubic meters (dscm) (60 dry standard cubic feet) 
per run. For Method 30B, each test run must be at least one hour in 
duration.
    (4) Determine the concentration of hydrogen chloride and hydrogen 
fluoride for each stack using Method 26A in 40 CFR part 60, appendix A. 
Each test must consist of three separate runs. The minimum sample 
volume must be at least 2 dscm per run.
    (5) During each stack test run, determine the weight of taconite 
pellets produced and calculate the emissions rate of each pollutant in 
pounds of pollutant per long ton (lb/LT) of pellets produced for each 
test run. The weight of taconite pellets produced must be determined by 
measurement using weigh hoppers, belt weigh feeders, or weighed 
quantities in shipments, or calculated using the bulk density and 
volume measurements. If any measurement result for any pollutant is 
reported as below the method detection limit, use the method detection 
limit as the measured emissions level for that pollutant when 
calculating the emission rate. If the furnace has more than one stack, 
calculate the total emissions rate for each test run by summing the 
emissions across all stacks, as shown in Equation 4.
[GRAPHIC] [TIFF OMITTED] TR06MR24.052

38Where:

E<INF>f,i</INF> = Emissions rate for test run ``i'' for all emission 
stacks on indurating furnace ``f'', lb/LT of pellets produced,
C<INF>s</INF> = Emission rate for stack ``s'' measured during test 
run ``i'' on indurating furnace ``f'', lb/dscf,
Q<INF>s</INF> = Average volumetric flow rate of stack gas measured 
at stack ``s'' during test run ``i'' on indurating furnace ``f'', 
dscf/hour;
P<INF>f</INF> = Pellets produced in indurating furnace ``f'' during 
the stack test, LT; and
n = Number of emissions stacks on furnace ``f''.

    (6) Calculate the average emissions rate for each furnace using the 
three test runs, as show in Equation 5 of this section.

[GRAPHIC] [TIFF OMITTED] TR06MR24.053

Where:


[[Page 16428]]


E<INF>f</INF> = Average emission rate for indurating furnace ``f'', 
lb/LT of pellets produced,
E<INF>1</INF> = Emissions rate for run 1 for indurating furnace 
``f'', lb/LT of pellets produced,
E<INF>2</INF> = Emissions rate for run 2 for indurating furnace 
``f'', lb/LT of pellets produced, and
E<INF>3</INF> = Emissions rate for run 3 for indurating furnace 
``f'', lb/LT of pellets produced.

    (7) For each indurating furnace constructed or reconstructed on or 
after May 15, 2023, determine compliance with the applicable mercury 
emission limit in table 2 to this subpart by calculating the average 
emissions rate from the three test runs performed on the furnace using 
Equations 4 and 5 of this section.
    (8) For each indurating furnace constructed or reconstructed before 
May 15, 2023, you must determine compliance with the applicable mercury 
emission limit in accordance with the procedures specified in either 
paragraph (d)(8)(i) or (ii) of this section.
    (i) Determine compliance with the mercury limit for individual 
furnaces in table 2 to this subpart by calculating the average mercury 
emissions rate for each affected indurating furnace using Equations 4 
and 5 of this section, or
    (ii) Determine compliance with the mercury limit for groups of 
indurating furnaces in table 2 to this subpart in accordance with the 
method in Sec.  63.9623(d).
    (9) Determine compliance with the applicable hydrogen chloride and 
hydrogen fluoride emission limits in table 3 to this subpart by 
calculating the average emissions rate for each indurating furnace for 
the three test runs performed on the furnace using Equations 4 and 5 of 
this section.
    (e) For each indurating furnace using mercury CEMS to demonstrate 
compliance with the applicable emission limits for mercury, you must 
determine compliance with the applicable mercury limit in table 2 to 
this subpart by using a 30-day rolling average of the 1-hour arithmetic 
average CEMS data, including CEMS data during startup and shutdown as 
defined in this subpart. The mercury CEMS must be installed, 
calibrated, maintained, and operated as accordance with the 
requirements in Sec.  63.9631(j).

0
9. Section 63.9622 is revised and republished to read as follows:


Sec.  63.9622  What test methods and other procedures must I use to 
establish and demonstrate initial compliance with the operating limits?

    (a) For wet scrubbers subject to performance testing in Sec.  
63.9620 and operating limits for pressure drop and scrubber water flow 
rate in Sec.  63.9590(b)(1), you must establish site-specific operating 
limits according to the procedures in paragraphs (a)(1) through (3) of 
this section.
    (1) Using the CPMS required in Sec.  63.9631(b), measure and record 
the pressure drop and scrubber water flow rate every 15 minutes during 
each run of the particulate matter performance test.
    (2) Calculate and record the average pressure drop and scrubber 
water flow rate for each individual test run. Your operating limits are 
established as the lowest average pressure drop and the lowest average 
scrubber water flow rate corresponding to any of the three test runs, 
except as specified in paragraph (g)(2) of this section.
    (3) If a rod-deck venturi scrubber is applied to an indurating 
furnace to meet any particulate matter emission limit in table 1 to 
this subpart, you may establish a lower average pressure drop operating 
limit by using historical average pressure drop data from a certified 
performance test completed on or after December 18, 2002 instead of 
using the average pressure drop value determined during the initial 
performance test, as specified in paragraph (a)(2) of this section. If 
historical average pressure drop data are used to establish an 
operating limit (i.e., using data from a certified performance test 
conducted prior to the promulgation date of the final rule), then the 
average particulate matter concentration corresponding to the 
historical performance test must be at or below the applicable 
indurating furnace emission limit, as listed in table 1 to this 
subpart.
    (b) On or before January 28, 2022, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, for dynamic wet scrubbers subject to performance testing in Sec.  
63.9620 and operating limits for scrubber water flow rate and either 
fan amperage or pressure drop in Sec.  63.9590(b)(2), you must 
establish site-specific operating limits according to the procedures in 
paragraphs (b)(1) and (2) of this section. After January 28, 2022, for 
affected sources that commenced construction or reconstruction on or 
before September 25, 2019, and after July 28, 2020, or upon start-up, 
which ever date is later, for affected sources that commenced 
construction or reconstruction after September 25, 2019, for dynamic 
wet scrubbers subject to performance testing in Sec.  63.9620 and 
operating limits for scrubber water flow rate and fan amperage in Sec.  
63.9590(b)(2), you must establish site-specific operating limits 
according to the procedures in paragraphs (b)(1) and (2) of this 
section.
    (1) On or before January 28, 2022, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, using the CPMS required in Sec.  63.9631(b), measure and record 
the scrubber water flow rate and either the fan amperage or pressure 
drop every 15 minutes during each run of the particulate matter 
performance test. After January 28, 2022, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, and after July 28, 2020, or upon start-up, which ever date is 
later, for affected sources that commenced construction or 
reconstruction after September 25, 2019, using the CPMS required in 
Sec.  63.9631(b), measure and record the scrubber water flow rate and 
the fan amperage every 15 minutes during each run of the particulate 
matter performance test.
    (2) On or before January 28, 2022, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, calculate and record the average scrubber water flow rate and 
either the average fan amperage or the average pressure drop for each 
individual test run. Your operating limits are established as the 
lowest average scrubber water flow rate and either the lowest average 
fan amperage or pressure drop value corresponding to any of the three 
test runs. After January 28, 2022, for affected sources that commenced 
construction or reconstruction on or before September 25, 2019, and 
after July 28, 2020, or upon start-up, which ever date is later, for 
affected sources that commenced construction or reconstruction after 
September 25, 2019, calculate and record the average scrubber water 
flow rate and the average fan amperage for each individual test run. 
Your operating limits are established as the lowest average scrubber 
water flow rate and the lowest average fan amperage value corresponding 
to any of the three test runs, except as specified in paragraph (g)(2) 
of this section.
    (c) For a dry ESP subject to performance testing in Sec.  63.9620 
and operating limits in Sec.  63.9590(b)(3), you must establish a site-
specific operating limit according to the procedures in paragraphs 
(c)(1) or (2) of this section.
    (1) If the operating limit for your dry ESP is a 6-minute average 
opacity of emissions value, then you must follow the requirements in 
paragraphs (c)(1)(i) through (iii) of this section.
    (i) Using the continuous opacity monitoring system (COMS) required 
in Sec.  63.9631(d)(1), measure and record the opacity of emissions 
from each control device stack during the particulate matter 
performance test.

[[Page 16429]]

    (ii) Compute and record the 6-minute opacity averages from 24 or 
more data points equally spaced over each 6-minute period (e.g., at 15-
second intervals) during the test runs.
    (iii) Using the opacity measurements from a performance test that 
meets the emission limit, determine the opacity value corresponding to 
the 99 percent upper confidence level of a normal distribution of the 
6-minute opacity averages.
    (2) If the operating limit for your dry ESP is the daily average 
secondary voltage and daily average secondary current for each field, 
then you must follow the requirements in paragraphs (c)(2)(i) and (ii) 
of this section.
    (i) Using the CPMS required in Sec.  63.9631(d)(2), measure and 
record the secondary voltage and secondary current for each dry ESP 
field every 15 minutes during each run of the particulate matter 
performance test.
    (ii) Calculate and record the average secondary voltage and 
secondary current for each dry ESP field for each individual test run. 
Your operating limits are established as the lowest average secondary 
voltage and secondary current value for each dry ESP field 
corresponding to any of the three test runs.
    (d) For a wet ESP subject to performance testing in Sec.  63.9620 
and operating limit in Sec.  63.9590(b)(4), you must establish a site-
specific operating limit according to the procedures in paragraphs 
(d)(1) and (2) of this section.
    (1) Using the CPMS required in Sec.  63.9631(e), measure and record 
the parametric values in paragraphs (d)(1)(i) through (iii) of this 
section for each wet ESP field every 15 minutes during each run of the 
particulate matter performance test.
    (i) Secondary voltage;
    (ii) Water flow rate; and
    (iii) Stack outlet temperature.
    (2) For each individual test run, calculate and record the average 
value for each operating parameter in paragraphs (d)(1)(i) through 
(iii) of this section for each wet ESP field. Your operating limits are 
established as the lowest average value for each operating parameter of 
secondary voltage and water flow rate corresponding to any of the three 
test runs, and the highest average value for each stack outlet 
temperature corresponding to any of the three test runs.
    (e) If you use an air pollution control device other than a wet 
scrubber, dynamic wet scrubber, dry ESP, wet ESP, or baghouse, and it 
is subject to performance testing in Sec.  63.9620, you must submit a 
site-specific monitoring plan in accordance with Sec.  63.9631(f). The 
site-specific monitoring plan must include the site-specific procedures 
for demonstrating initial and continuous compliance with the 
corresponding operating limits.
    (f) You may change the operating limits for any air pollution 
control device as long as you meet the requirements in paragraphs 
(f)(1) through (3) of this section.
    (1) Submit a written notification to the Administrator of your 
request to conduct a new performance test to revise the operating 
limit.
    (2) Conduct a performance test to demonstrate compliance with the 
applicable emission limitation in table 1 to this subpart.
    (3) Establish revised operating limits according to the applicable 
procedures in paragraphs (a) through (e) of this section.
    (g) For wet scrubbers and wet ESPs subject to performance testing 
in Sec.  63.9620(l) and operating limits for scrubber water flow rate 
and pH in Sec.  63.9590(b)(5), you must establish site-specific 
operating limits according to the procedures in paragraphs (g)(1) and 
(2) of this section.
    (1) Using the CPMS required in Sec.  63.9631(b), measure and record 
the scrubber water flow rate and pH of the scrubber water effluent 
every 15 minutes during each run of the performance test for hydrogen 
chloride and hydrogen fluoride.
    (2) Calculate and record the average scrubber water flow rate and 
average pH of the scrubber water effluent for each individual test run. 
Your operating limit must be established as the average scrubber water 
flow rate and average pH of the scrubber water of the three test runs. 
If a higher average flow rate is measured during the most recent PM 
performance test, the operating limit for the daily average scrubber 
water flow rate is the average scrubber water flow rate measured during 
the most recent PM performance test. If a higher average flow rate is 
measured during the most recent HCl and HF performance test, the 
operating limit for the daily average scrubber water flow rate is the 
average scrubber water flow rate measured during the most recent HCl 
and HF performance test.
    (h) For ACI systems subject to performance testing in Sec.  
63.9620(k)(1) and operating limits for activated carbon sorbent 
injection rate and carrier gas flow rate in Sec.  63.9590(b)(6), you 
must establish site-specific operating limits according to the 
procedures in paragraphs (h)(1) and (2) of this section.
    (1) Using the CPMS required in Sec.  63.9631(b), measure and record 
the activated carbon injection rate and carrier gas flow rate every 15 
minutes during each run of the performance test for mercury.
    (2) Calculate and record the average activated carbon injection 
rate and carrier gas flow rate for each individual test run. Your 
operating limit must be established as the highest activated carbon 
injection rate and carrier gas flow rate of the three test runs.
    (i) For DSI systems subject to performance testing in Sec.  
63.9620(l) and operating limits for sorbent injection rate and carrier 
gas flow rate in Sec.  63.9590(b)(7), you must establish site-specific 
operating limits according to the procedures in paragraphs (i)(1) and 
(2) of this section.
    (1) Using the CPMS required in Sec.  63.9631(b), measure and record 
the sorbent injection rate and carrier gas flow rate every 15 minutes 
during each run of the performance test for hydrogen chloride and 
hydrogen fluoride.
    (2) Calculate and record the average sorbent injection rate and 
carrier gas flow rate for each individual test run. Your operating 
limit must be established as the highest average sorbent injection rate 
and carrier gas flow rate of the three test runs.

0
10. Section 63.9623 is revised and republished to read as follows:


Sec.  63.9623  How do I demonstrate initial compliance with the 
emission limitations that apply to me?

    (a) For each affected source subject to an emission limit in tables 
1 through 3 to this subpart, you must demonstrate initial compliance by 
meeting the emission limit requirements in paragraphs (a)(1) through 
(8) of this section by the compliance date specified in Sec.  63.9583.
    (1) For ore crushing and handling, the flow-weighted mean 
concentration of particulate matter, determined according to the 
procedures in Sec. Sec.  63.9620(a) and 63.9621(b), must not exceed the 
emission limits in table 1 to this subpart.
    (2) For indurating furnaces, the flow-weighted mean concentration 
of particulate matter, determined according to the procedures in 
Sec. Sec.  63.9620(b) and 63.9621(c), must not exceed the emission 
limits in table 1 to this subpart.
    (3) For finished pellet handling, the flow-weighted mean 
concentration of particulate matter, determined according to the 
procedures in Sec. Sec.  63.9620(c) and 63.9621(b), must not exceed the 
emission limits in table 1 to this subpart.
    (4) For ore dryers, the flow-weighted mean concentration of 
particulate matter, determined according to the

[[Page 16430]]

procedures in Sec. Sec.  63.9620(d) and 63.9621(c), must not exceed the 
emission limits in table 1 to this subpart.
    (5) For indurating furnaces not using emissions averaging, the 
mercury emissions determined according to the procedures in Sec. Sec.  
63.9620(k)(1) or (2) and 63.9621(d), must not exceed the applicable 
emission limit in table 2 to this subpart.
    (6) For indurating furnaces that comply with the mercury emissions 
limit using emissions averaging, the average mercury emissions 
determined according to the procedures in Sec. Sec.  63.9620(k)(1) or 
(2), 63.9621(d) and 63.9634(m), must not exceed the applicable emission 
limit in table 2 to this subpart.
    (7) For indurating furnaces that comply with the mercury emissions 
limit by adjusting the activated carbon injection rate based on the 
taconite pellet production rate, the mercury emissions determined 
according to the procedures in Sec. Sec.  63.9620(k)(1) or (2), 
63.9621(d) or (e), and 63.9634(n), must not exceed the applicable 
emission limit in table 2 to this subpart.
    (8) For indurating furnaces, the hydrogen chloride and hydrogen 
fluoride emissions determined according to the procedures in Sec. Sec.  
63.9620(l) and 63.9621(d), must not exceed the applicable emission 
limit in table 3 to this subpart.
    (b) For each affected source subject to an emission limit in table 
1 to this subpart, you must demonstrate initial compliance by meeting 
the operating limit requirements in paragraphs (b)(1) through (5) of 
this section.
    (1) For each wet scrubber subject to performance testing in Sec.  
63.9620 and operating limits for pressure drop and scrubber water flow 
rate in Sec.  63.9590(b)(1), you have established appropriate site-
specific operating limits and have a record of the pressure drop and 
scrubber water flow rate measured during the performance test in 
accordance with Sec.  63.9622(a).
    (2) On or before January 28, 2022, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, for each dynamic wet scrubber subject to performance testing in 
Sec.  63.9620 and operating limits for scrubber water flow rate and 
either fan amperage or pressure drop in Sec.  63.9590(b)(2), you have 
established appropriate site-specific operating limits and have a 
record of the scrubber water flow rate and either the fan amperage or 
pressure drop value, measured during the performance test in accordance 
with Sec.  63.9622(b). After January 28, 2022, for affected sources 
that commenced construction or reconstruction on or before September 
25, 2019, and after July 28, 2020, or upon start-up, which ever date is 
later, for affected sources that commenced construction or 
reconstruction after September 25, 2019, for each dynamic wet scrubber 
subject to performance testing in Sec.  63.9620 and operating limits 
for scrubber water flow rate and fan amperage in Sec.  63.9590(b)(2), 
you have established appropriate site-specific operating limits and 
have a record of the scrubber water flow rate and the fan amperage 
value, measured during the performance test in accordance with Sec.  
63.9622(b).
    (3) For each dry ESP subject to performance testing in Sec.  
63.9620 and one of the operating limits in Sec.  63.9590(b)(3), you 
must meet the requirements in paragraph (b)(3)(i) or (ii) of this 
section.
    (i) If you are subject to the operating limit for opacity in Sec.  
63.9590(b)(3)(i), you have established appropriate site-specific 
operating limits and have a record of the opacity measured during the 
performance test in accordance with Sec.  63.9622(c)(1).
    (ii) If you are subject to the operating limit for secondary 
voltage and secondary current in Sec.  63.9590(b)(3)(ii), you have 
established appropriate site-specific operating limits and have a 
record of the secondary voltage and secondary current measured during 
the performance test in accordance with Sec.  63.9622(c)(2).
    (4) For each wet ESP subject to performance testing in Sec.  
63.9620 and operating limits for secondary voltage, water flow rate, 
and stack outlet temperature in Sec.  63.9590(b)(4), you have 
established appropriate site-specific operating limits and have a 
record of the secondary voltage, water flow rate, and stack outlet 
temperature measured during the performance test in accordance with 
Sec.  63.9622(d).
    (5) For other air pollution control devices subject to performance 
testing in Sec.  63.9620 and operating limits in accordance with Sec.  
63.9590(b)(8), you have submitted a site-specific monitoring plan in 
accordance with Sec.  63.9631(f) and have a record of the site-specific 
operating limits as measured during the performance test in accordance 
with Sec.  63.9622(e).
    (c) Except as specified in paragraph (e) of this section, you must 
demonstrate initial compliance with the emission limits in tables 2 and 
3 to this subpart, by meeting the operating limit requirements in 
paragraphs (c)(1) through (3) of this section.
    (1) For each wet scrubber and wet ESP subject to performance 
testing in Sec.  63.9620(k) and operating limits for scrubber water 
flow rate and pH in Sec.  63.9590(b)(5), you have established 
appropriate site-specific operating limits and have a record of the 
scrubber water flow rate and pH measured during the performance test in 
accordance with Sec.  63.9622(g).
    (2) For each ACI subject to performance testing in Sec.  63.9620(k) 
and operating limits for activated carbon injection rate and carrier 
gas flow rate in Sec.  63.9590(b)(6), you have established appropriate 
site-specific operating limits and have a record of the activated 
carbon injection rate and carrier gas flow rate measured during the 
performance test in accordance with Sec.  63.9622(i).(3) For each DSI 
subject to performance testing in Sec.  63.9620(k) and operating limits 
for sorbent injection rate and carrier gas flow rate in Sec.  
63.9590(b)(7), you have established appropriate site-specific operating 
limit and have a record of the sorbent injection rate and carrier gas 
flow rate measured during the performance test in accordance with Sec.  
63.9622(h).
    (d) If you elect to comply with the mercury limit in table 2 to 
this subpart using emissions averaging for indurating furnaces 
constructed or reconstructed before May 15, 2023, you must comply with 
the requirements in paragraphs (d)(1) through (4) of this section.
    (1) Before submitting the implementation plan required in paragraph 
(d)(3) of this section, you must complete the mercury stack testing 
required in Sec.  63.9620(k)(1) or install, calibrate, and operate a 
mercury CEMS pursuant to Sec.  63.9620(k)(2) and paragraph (e) of this 
section for all indurating furnaces you wish to include in the mercury 
emission average.
    (2) You must develop and submit to the applicable regulatory 
authority for review and approval, an implementation plan for mercury 
emission averaging no later than 180 days before the date you intend to 
demonstrate compliance using the emission averaging option. You must 
include the information contained in paragraphs (d)(2)(i) through (iii) 
of this section in your implementation plan.
    (i) Identification of all indurating furnaces in the averaging 
group, including the typical taconite pellet production rate, control 
technology installed, and types of fuel(s) that will be burned.
    (ii) The mercury emission rate for each furnace for each of the 
fuels identified in paragraph (d)(2)(i) of this section.
    (iii) The date on which you are requesting emission averaging to 
commence.

[[Page 16431]]

    (3) The regulatory authority shall review and approve or disapprove 
the plan according to the following criteria:
    (i) Whether the content of the plan includes all the information 
specified in paragraph (d)(2) of this section, and
    (ii) Whether the plan presents sufficient information to determine 
that compliance will be achieved and maintained.
    (4) The applicable regulatory authority shall not approve an 
emission averaging implementation plan containing any of the following 
provisions:
    (i) Averaging that includes indurating furnaces constructed or 
reconstructed on or after May 15, 2023, or
    (ii) Averaging between indurating furnaces located at different 
facilities.
    (e) If you elect to demonstrate compliance with the mercury limit 
in table 2 to this subpart using a mercury CEMS, you must calculate the 
30-day rolling average of 1-hour arithmetic average emission 
concentrations, including CEMS data during startup and shutdown, 
calculated using equation 19-19 in section 12.4.1 of EPA Reference 
Method 19 at appendix A-7 of 40 CFR part 60. The 1-hour arithmetic 
averages for CEMS must be calculated using the data points required 
under Sec.  63.8(c)(4)(ii).
    (f) For each emission limitation and operating limit that applies 
to you, you must submit a notification of compliance status according 
to Sec.  63.9640(e)

0
11. Section 63.9630 is amended by revising paragraphs (b) and (e)(2) to 
read as follows:


Sec.  63.9630  When must I conduct subsequent performance tests?

* * * * *
    (b) You must conduct subsequent performance tests on all stacks 
associated with indurating furnaces to demonstrate continued compliance 
with the indurating furnace emission limits in tables 1 through 3 to 
this subpart according to the schedule developed by your permitting 
authority and shown in your title V permit, but no less frequent than 
twice per 5-year permit term. If a title V permit has not been issued, 
you must submit a testing plan and schedule, containing the information 
specified in paragraph (e) of this section, to the permitting authority 
for approval. For an indurating furnace with multiple stacks, the 
performance tests for all stacks must be conducted within 7 calendar 
days of commencement of the performance tests, to the extent 
practicable, and the indurating furnace and associated control device 
(where applicable) operating characteristics must remain representative 
and consistent for the duration of the stack tests. If you determine 
that the performance tests cannot be completed within 7 calendar days, 
the Administrator must be notified within 24 hours of making that 
determination. Performance testing for mercury is not required for 
furnaces using CEMS to demonstrate compliance with the mercury emission 
limits in table 2 to this subpart.
* * * * *
    (e) * * *
    (2) A schedule indicating when you will conduct subsequent 
performance tests for particulate matter, mercury, hydrogen chloride 
and hydrogen fluoride for each of the emission units.

0
12. Section 63.9631 is amended by:
0
a. Revising and republishing paragraphs (d) through (f); and
0
b. Adding paragraphs (g) through (k).
    The revisions and additions read as follows:


Sec.  63.9631  What are my monitoring requirements?

* * * * *
    (d) For each dry ESP subject to the operating limits in Sec.  
63.9590(b)(3), you must follow the monitoring requirements in paragraph 
(d)(1) or (2) of this section.
    (1) If the operating limit you choose to monitor is the 6-minute 
average opacity of emissions in accordance with Sec.  63.9590(b)(3)(i), 
you must install, operate, and maintain a COMS according to the 
requirements in Sec.  63.9632(f) and monitor the 6-minute average 
opacity of emissions exiting each control device stack according to the 
requirements in Sec.  63.9633.
    (2) If the operating limit you choose to monitor is average 
secondary voltage and average secondary current for each dry ESP field 
in accordance with Sec.  63.9590(b)(3)(ii), you must install, operate, 
and maintain a CPMS according to the requirements in Sec.  63.9632(b) 
through (e) and monitor the daily average secondary voltage and daily 
average secondary current according to the requirements in Sec.  
63.9633.
    (e) For each wet ESP subject to the operating limits in Sec.  
63.9590(b)(4), you must install, operate, and maintain a CPMS according 
to the requirements in Sec.  63.9632(b) through (e) and monitor the 
daily average secondary voltage, daily average stack outlet 
temperature, and daily average water flow rate according to the 
requirements in Sec.  63.9633.
    (f) For each wet scrubber and wet ESP subject to the operating 
limits in Sec.  63.9590(b)(5), you must install, operate, and maintain 
a CPMS according to the requirements in Sec.  63.9632(g) and monitor 
the daily average scrubber water flow rate and pH of the scrubber water 
effluent.
    (g) For each ACI system subject to the operating limits in Sec.  
63.9590(b)(6), you must install, operate, and maintain a CPMS according 
to the requirements in Sec.  63.9632(h) and (i) and monitor the daily 
average activated carbon injection rate and carrier gas flow rate.
    (h) For each DSI system subject to the operating limits in Sec.  
63.9590(b)(7), you must install, operate, and maintain a CPMS according 
to the requirements in Sec.  63.9632(h) and (i) and monitor the daily 
average sorbent injection rate and carrier gas flow rate.
    (i) If you use any air pollution control device other than a 
baghouse, wet scrubber, dry ESP, wet ESP, DSI, or ACI, you must submit 
a site-specific monitoring plan that includes the information in 
paragraphs (i)(1) through (4) of this section. The monitoring plan is 
subject to approval by the Administrator. You must maintain a current 
copy of the monitoring plan onsite, and it must be available for 
inspection upon request. You must keep the plan for the life of the 
affected source or until the affected source is no longer subject to 
the requirements of this subpart.
    (1) A description of the device.
    (2) Test results collected in accordance with Sec.  63.9621 
verifying the performance of the device for reducing emissions of 
particulate matter, mercury, hydrogen chloride, and hydrogen fluoride 
to the atmosphere to the levels required by this subpart.
    (3) A copy of the operation and maintenance plan required in Sec.  
63.9600(b).
    (4) Appropriate operating parameters that will be monitored to 
maintain continuous compliance with the applicable emission 
limitation(s).
    (j) If you elect to comply with the mercury limit in table 2 to 
this subpart using emissions averaging in accordance with an 
implementation plan approved under the provisions in Sec.  63.9623(d) 
or you elect to adjust the activated carbon injection rate based on the 
taconite pellet production rate in accordance with the procedures in 
Sec.  63.9634(n), you must determine and record the mass of taconite 
pellets produced each month by each furnace included in the emissions 
averaging group. The weight of taconite pellets produced must be 
determined by measurement using weigh hoppers, belt weigh feeders, or 
weighed quantities in shipments, or calculated using the bulk density 
and volume measurements.

[[Page 16432]]

    (k) If you elect to demonstrate compliance with the mercury 
emissions limits in table 2 to this subpart using a CEMS to measure 
mercury emissions, you must comply with the requirements in (k)(1) 
through (5).
    (1) Notify the Administrator one month before starting use of the 
CEMS and notify the Administrator 180-days before ceasing use of the 
CEMS.
    (2) Each CEMS must be installed, certified, calibrated, and 
maintained according to the requirements of performance specifications 
6 and 12A of 40 CFR part 60, appendix B, and quality assurance 
procedure 6 of 40 CFR part 60, appendix F.
    (3) Operate the mercury CEMS in accordance with performance 
specification 12A of 40 CFR part 60, appendix B. The duration of the 
performance test must be 30 operating days. For each day in which the 
unit operates, you must obtain hourly mercury concentration data, and 
stack gas volumetric flow rate data.
    (4) You must complete the initial performance evaluation of the 
CEMS within 180 days after notifying the Administrator and before 
starting to use the CEMS data in lieu of performance testing and 
monitoring operating parameters to demonstrate compliance.
    (5) Collect CEMS hourly averages for all operating hours on a 30-
day rolling average basis. The one-hour arithmetic averages, expressed 
in units of lb/LT, must be used to calculate 30-day rolling average 
emissions to determine compliance with the applicable emission limit in 
table 2 to this subpart.

0
13. Section 63.9632 is amended by:
0
a. Revising paragraphs (f) introductory text and (f)(2); and
0
b. Adding paragraphs (g) through (i).
    The revisions and additions read as follows:


Sec.  63.9632  What are the installation, operation, and maintenance 
requirements for my monitoring equipment?

* * * * *
    (f) For each dry ESP subject to the opacity operating limit in 
Sec.  63.9590(b)(3)(i), you must install, operate, and maintain each 
COMS according to the requirements in paragraphs (f)(1) through (4) of 
this section.
* * * * *
    (2) On or before January 25, 2021, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, you must develop and implement a quality control program for 
operating and maintaining each COMS according to Sec.  63.8. At a 
minimum, the quality control program must include a daily calibration 
drift assessment, quarterly performance audit, and annual zero 
alignment of each COMS. After January 25, 2021, for affected sources 
that commenced construction or reconstruction on or before September 
25, 2019, and after July 28, 2020, or upon start-up, which ever date is 
later, for affected sources that commenced construction or 
reconstruction after September 25, 2019, you must develop and implement 
a quality control program for operating and maintaining each COMS 
according to Sec.  63.8(a) and (b), (c)(1)(ii), (c)(2) through (8), 
(d)(1) and (2), and (e) through (g) and Procedure 3 in appendix F to 40 
CFR part 60. At a minimum, the quality control program must include a 
daily calibration drift assessment, quarterly performance audit, and 
annual zero alignment of each COMS.
* * * * *
    (g) For each pH measurement device, in addition to the requirements 
in paragraphs (b) through (e) of this section, you must meet the 
requirements in paragraphs (g)(1) through (4) of this section.
    (1) The minimum accuracy of the pH measurement device must be 
<plus-minus>0.2 pH units.
    (2) Locate the pH sensor in a position that provides a 
representative measurement of scrubber effluent pH.
    (3) Ensure the sample is properly mixed and representative of the 
fluid to be measured.
    (4) Check the pH meter's calibration on at least two points every 8 
hours of process operation.
    (h) For each mass flow rate monitor used for measuring the sorbent 
or activated carbon injection rate, in addition to the requirements in 
paragraphs (b) through (e) of this section, you must meet the 
requirements of (h)(1) through (4) of this section.
    (1) The minimum accuracy of the mass flow rate monitor must be 
<plus-minus>5 percent over the normal range of flow measured.
    (2) Locate the device in a position(s) that provides a 
representative measurement of the total sorbent injection rate.
    (3) Install and calibrate the device in accordance with 
manufacturer's procedures and specifications.
    (4) At least annually, conduct a performance evaluation of the 
injection rate monitoring system in accordance with your monitoring 
plan.
    (i) For each carrier gas flow rate monitor, in addition to the 
requirements in paragraphs (b) through (e) of this section, you must 
meet the requirements of (i)(1) through (4) of this section.
    (1) The minimum accuracy of the gas flow rate monitor must be 
<plus-minus>5 percent over the normal range of flow measured or 280 
liters per minute (10 cubic feet per minute), whichever is greater.
    (2) Locate the device in a position(s) that provides a 
representative measurement of the carrier gas flow rate.
    (3) Install and calibrate the device in accordance with 
manufacturer's procedures and specifications.
    (4) At least annually, conduct a performance evaluation of the 
carrier gas flow rate monitoring system in accordance with your 
monitoring plan.

0
14. Section 63.9634 is amended by revising paragraphs (a), (e)(4), 
(f)(4), (g) through (j) and adding paragraphs (k) through (n) to read 
as follows:


Sec.  63.9634  How do I demonstrate continuous compliance with the 
emission limitations that apply to me?

    (a) For each affected source subject to an emission limit in table 
1 to this subpart, you must demonstrate continuous compliance by 
meeting the requirements in paragraphs (b) through (h) of this section.
* * * * *
    (e) * * *
    (4) If the daily average pressure drop or daily average scrubber 
water flow rate is below the operating limits established for a 
corresponding emission unit or group of similar emission units, you 
must then follow the corrective action procedures in paragraph (l) of 
this section.
    (f) * * *
    (4) On or before January 28, 2022, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, if the daily average scrubber water flow rate, daily average fan 
amperage, or daily average pressure drop is below the operating limits 
established for a corresponding emission unit or group of similar 
emission units, you must then follow the corrective action procedures 
in paragraph (l) of this section. After January 28, 2022, for affected 
sources that commenced construction or reconstruction on or before 
September 25, 2019, and after July 28, 2020, or upon start-up, which 
ever date is later, for affected sources that commenced construction or 
reconstruction after September 25, 2019, if the daily average scrubber 
water flow rate or daily average fan amperage, is below the operating 
limits established for a corresponding emission unit or group of 
similar emission units, you must then follow the corrective action 
procedures in paragraph (l) of this section.
    (g) For each dry ESP subject to operating limits in Sec.  
63.9590(b)(3), you

[[Page 16433]]

must demonstrate continuous compliance by completing the requirements 
of paragraph (g)(1) or (2) of this section.
    (1) If the operating limit for your dry ESP is a 6-minute average 
opacity of emissions value, then you must follow the requirements in 
paragraphs (g)(1)(i) through (iii) of this section.
    (i) Maintaining the 6-minute average opacity of emissions at or 
below the maximum level established during the initial or subsequent 
performance test.
    (ii) Operating and maintaining each COMS and reducing the COMS data 
according to Sec.  63.9632(f).
    (iii) If the 6-minute average opacity of emissions is above the 
operating limits established for a corresponding emission unit, you 
must then follow the corrective action procedures in paragraph (l) of 
this section.
    (2) If the operating limit for your dry ESP is the daily average 
secondary voltage and daily average secondary current for each field, 
then you must follow the requirements in paragraphs (g)(2)(i) through 
(iv) of this section.
    (i) Maintaining the daily average secondary voltage or daily 
average secondary current for each field at or above the minimum levels 
established during the initial or subsequent performance test.
    (ii) Operating and maintaining each dry ESP CPMS according to Sec.  
63.9632(b) and recording all information needed to document conformance 
with these requirements.
    (iii) Collecting and reducing monitoring data for secondary voltage 
or secondary current for each field according to Sec.  63.9632(c) and 
recording all information needed to document conformance with these 
requirements.
    (iv) If the daily average secondary voltage or daily average 
secondary current for each field is below the operating limits 
established for a corresponding emission unit, you must then follow the 
corrective action procedures in paragraph (l) of this section.
    (h) For each wet ESP subject to the operating limits for secondary 
voltage, stack outlet temperature, and water flow rate in Sec.  
63.9590(b)(4), you must demonstrate continuous compliance by completing 
the requirements of paragraphs (h)(1) through (4) of this section.
    (1) Maintaining the daily average secondary voltage and daily 
average scrubber water flow rate for each field at or above the minimum 
levels established during the initial or subsequent performance test. 
Maintaining the daily average stack outlet temperature at or below the 
maximum levels established during the initial or subsequent performance 
test.
    (2) Operating and maintaining each wet ESP CPMS according to Sec.  
63.9632(b) and recording all information needed to document conformance 
with these requirements.
    (3) Collecting and reducing monitoring data for secondary voltage, 
stack outlet temperature, and water flow rate according to Sec.  
63.9632(c) and recording all information needed to document conformance 
with these requirements.
    (4) If the daily average secondary voltage, stack outlet 
temperature, or water flow rate does not meet the operating limits 
established for a corresponding emission unit, you must then follow the 
corrective action procedures in paragraph (l) of this section.
    (i) For each affected indurating furnace subject to a hydrogen 
chloride and hydrogen fluoride emission limit in table 3 to this 
subpart, you must demonstrate continuous compliance by meeting the 
requirements in paragraphs (i)(1) and (2) of this section.
    (1) For each wet scrubber and wet ESP subject to the operating 
limits for scrubber water flow rate and pH in Sec.  63.9590(b)(5), you 
must demonstrate continuous compliance by completing the requirements 
of paragraphs (i)(1)(i) through (iv) of this section.
    (i) Maintaining the daily average scrubber water flow rate and 
daily average pH of the scrubber water effluent at or above the minimum 
level established during the most recent performance test. If a higher 
average flow rate is measured during the last PM performance test, the 
operating limit for daily average scrubber water flow rate is the 
highest average scrubber water flow rate measured during the last PM 
performance test.
    (ii) Operating and maintaining each of the CPMS used to measure 
scrubber water flow rate and pH according to Sec.  63.9632(g) and 
recording all information needed to document conformance with these 
requirements.
    (iii) Collecting and reducing monitoring data for scrubber water 
flow rate and pH according to Sec.  63.9632(c) and recording all 
information needed to document conformance with these requirements.
    (iv) If the daily average scrubber water flow rate or daily average 
pH is below the operating limits established for control device, you 
must follow the corrective action procedures in paragraph (l) of this 
section.
    (2) For each DSI subject to the operating limits for sorbent 
injection rate and carrier gas flow rate in Sec.  63.9590(b)(7), you 
must demonstrate continuous compliance by completing the requirements 
of paragraphs (i)(2)(i) through (iv) of this section.
    (i) Maintain the daily average sorbent injection rate and carrier 
gas flow rate at or above the minimum level established during the most 
recent performance test.
    (ii) Operate and maintain each CPMS used to measure the sorbent 
injection rate according to Sec.  63.9632(h) and the carrier gas flow 
rate according to Sec.  63.9632(i) and recording all information needed 
to document compliance with these requirements.
    (iii) Collect and reduce monitoring data for the sorbent injection 
rate and carrier gas flow rate according to Sec.  63.9632(c) and 
recording all information needed to document compliance with these 
requirements.
    (iv) If the daily average the sorbent injection rate or carrier gas 
flow rate is below the operating limit established for the control 
device, you must follow the corrective action procedures in paragraph 
(l) of this section.
    (j) For each affected indurating furnace using ACI to comply with 
the mercury emission limit in table 2 to this subpart, you must 
demonstrate continuous compliance by meeting the requirements of 
paragraphs (j)(1) or (2) of this section.
    (1) If you use CEMS to demonstrate compliance, you must comply with 
the requirements in paragraphs (j)(1)(i) and (ii) of this section.
    (i) You must operate a mercury CEMS in accordance with performance 
specification 12A at 40 CFR part 60, appendix B; these monitoring 
systems must be quality assured according to procedure 5 of 40 CFR 60, 
appendix F. You must demonstrate compliance with the mercury emissions 
limit using a 30-day rolling average of these 1-hour mercury 
concentrations or mass emissions rates, including CEMS data during 
startup and shutdown as defined in this subpart, calculated using 
equation 19-19 in section 12.4.1 of EPA Reference Method 19 at 40 CFR 
part 60, appendix A-7 of this part.
    (ii) Owners or operators using a mercury CEMS to determine mass 
emission rate must install, operate, calibrate and maintain an 
instrument for continuously measuring and recording the mercury mass 
emissions rate to the atmosphere according to the requirements of 
performance specification 6 at 40 CFR part 60, appendix B and 
conducting an annual relative accuracy test of the continuous emission 
rate monitoring system according to section 8.2 of performance 
specification 6.

[[Page 16434]]

    (2) If you do not use CEMS to demonstrate compliance, you must 
demonstrate continuous compliance by meeting the requirements of 
paragraphs (j)(2)(i) through (iv) of this section.
    (i) Maintain the daily average activated carbon injection rate and 
carrier gas flow rate at or above the minimum level established during 
the most recent performance test.
    (ii) Operate and maintain each CPMS used to measure the activated 
carbon injection rate according to Sec.  63.9632(h) and the carrier gas 
flow rate according to Sec.  63.9632(i), and record all information 
needed to document compliance with these requirements.
    (iii) Collect and reduce monitoring data for the activated carbon 
injection rate and carrier gas flow rate according to Sec.  63.9632(c) 
and record all information needed to document conformance with these 
requirements.
    (iv) If the daily average of the activated carbon injection rate or 
carrier gas flow rate is below the operating limit established for the 
control device, you must follow the corrective action procedures in 
paragraph (l) of this section.
    (k) If you use an air pollution control device other than a wet 
scrubber, dynamic wet scrubber, dry ESP, wet ESP, DSI, ACI, or 
baghouse, you must submit a site-specific monitoring plan in accordance 
with Sec.  63.9631(f). The site-specific monitoring plan must include 
the site-specific procedures for demonstrating initial and continuous 
compliance with the corresponding operating limits.
    (l) If the daily average operating parameter value for an emission 
unit or group of similar emission units does not meet the corresponding 
established operating limit, you must then follow the procedures in 
paragraphs (l)(1) through (4) of this section.
    (1) You must initiate and complete initial corrective action within 
10 calendar days and demonstrate that the initial corrective action was 
successful. During any period of corrective action, you must continue 
to monitor, and record all required operating parameters for equipment 
that remains in operation. After the initial corrective action, if the 
daily average operating parameter value for the emission unit or group 
of similar emission units meets the operating limit established for the 
corresponding unit or group, then the corrective action was successful 
and the emission unit or group of similar emission units is in 
compliance with the established operating limits.
    (2) If the initial corrective action required in paragraph (l)(1) 
of this section was not successful, then you must complete additional 
corrective action within 10 calendar days and demonstrate that the 
subsequent corrective action was successful. During any period of 
corrective action, you must continue to monitor, and record all 
required operating parameters for equipment that remains in operation. 
If the daily average operating parameter value for the emission unit or 
group of similar emission units meets the operating limit established 
for the corresponding unit or group, then the corrective action was 
successful, and the emission unit or group of similar emission units is 
in compliance with the established operating limits.
    (3) If the second attempt at corrective action required in 
paragraph (l)(2) of this section was not successful, then you must 
repeat the procedures of paragraph (l)(2) of this section until the 
corrective action is successful. If the third attempt at corrective 
action is unsuccessful, you must conduct another performance test in 
accordance with the procedures in Sec.  63.9622(f) and report to the 
Administrator as a deviation the third unsuccessful attempt at 
corrective action.
    (4) After the third unsuccessful attempt at corrective action, you 
must submit to the Administrator the written report required in 
paragraph (l)(3) of this section within 5 calendar days after the third 
unsuccessful attempt at corrective action. This report must notify the 
Administrator that a deviation has occurred and document the types of 
corrective measures taken to address the problem that resulted in the 
deviation of established operating parameters and the resulting 
operating limits.
    (m) If you elect to comply with the mercury limit in table 2 to 
this subpart using emissions averaging in accordance with an 
implementation plan approved under the provisions in Sec.  63.9623(d), 
you must comply with the requirements in paragraphs (m)(1) through (5) 
of this section.
    (1) For furnaces included in the emissions averaging group that do 
not use mercury CEMS, you must comply with the requirements in 
paragraph (m)(1)(i) or (ii) as applicable.
    (i) For furnaces equipped with ACI systems, you must comply with 
the requirements in paragraph (j) of this section.
    (ii) For furnaces equipped with a mercury control device or method 
other than ACI, you must comply with your site-specific monitoring plan 
in accordance with the requirements in paragraph (k) of this section.
    (2) For furnaces included in the emissions averaging group that use 
mercury CEMS, you must comply with the requirements in paragraph (i)(1) 
of this section.
    (3) Calculate the monthly production-weighted average emission rate 
using either the mercury CEMS data or mercury emission rate determined 
during the last performance test and the actual taconite pellet 
production data for each furnace included in the emissions averaging 
option, as shown in Equation 6 of this section.
[GRAPHIC] [TIFF OMITTED] TR06MR24.054

Where:

E<INF>g</INF> = Monthly production-weighted average mercury emission 
rate for month ``g'' for the group of indurating furnaces, lb/LT of 
pellets produced,
E<INF>f</INF> = Average mercury emission rate for furnace ``f'', as 
determined using either mercury CEMS data or the emission rate 
determined during the last compliance stack test and calculated 
using Equation 5 of Sec.  63.9621(d)(7)(i), lb/LT of pellets 
produced,
P<INF>f</INF> = Total monthly production of finished taconite 
pellets for furnace ``f'', in LT, and
n = Number of furnaces in the averaging group.

    (4) Until 12 monthly weighted average emission rates have been 
accumulated, the monthly weighted average emissions rate, calculated as 
shown in paragraph (m)(3) of this section, must not exceed the mercury 
emission limit in table 3 of this subpart in any calendar month.
    (5) After 12 monthly weighted average emission rates have been 
accumulated, for each subsequent calendar month, you must use Equation 
7 of this section to calculate the 12-month rolling average of the 
monthly weighted average emission rates for the current month and the 
previous 11 months. The 12-month rolling weighted average emissions 
rate for the furnaces included in the group must not exceed the mercury 
emission limit in table 3 of this subpart.
[GRAPHIC] [TIFF OMITTED] TR06MR24.055

Where:

E<INF>avg</INF> = 12-month rolling average emission rate, lb/LT.
E<INF>i</INF> = Monthly weighted average for month ``i'' calculated 
as shown in Equation 6 of this section.

    (n) You may elect to demonstrate continuous compliance with the 
mercury limit in table 2 to this subpart by adjusting the activated 
carbon injection rate based on the taconite pellet production rate. You 
must comply with the requirements in

[[Page 16435]]

paragraphs (n)(1) through (7) of this section.
    (1) Measure the activated carbon injection and mercury emissions 
rate at a minimum of three different production levels corresponding to 
the maximum, minimum and median finished taconite pellet production 
rates, using the methods specified in Sec.  63.9620(k).
    (2) Develop a correlation curve by plotting the production rate and 
corresponding carbon injection rate for the maximum, median and minimum 
production rates. Use only data where the mercury emission rate is 
below the applicable mercury emissions standard in table 2 to this 
subpart. Plot the production rates as the independent (or x) variable 
and the activated carbon injection rate as the dependent (or y) 
variable for each pellet production rate. Construct the graph by 
drawing straight line segments between each point plotted.
    (3) You must develop and submit to the applicable regulatory 
authority for review and approval, an implementation plan no later than 
180 days before the date you intend to demonstrate compliance by 
adjusting the activated carbon injection rate based on the taconite 
pellet production. You must include the information listed in 
paragraphs (n)(3)(i) through (iv) of this section in your 
implementation plan.
    (i) Identification of the indurating furnace, including the typical 
maximum and minimum taconite pellet production rate, mercury control 
technology installed, and types of fuel(s) that will be burned.
    (ii) The mercury emissions and activated carbon injection rates at 
maximum, median and minimum taconite pellet production rates, and the 
methods used to measure the mercury emissions, activated carbon 
injection rate and taconite pellet production.
    (iii) The correlation curve developed in paragraph (n)(2) of this 
section.
    (iv) The date on which you are requesting to commence adjusting the 
activated carbon rate based on the taconite production rate.
    (4) Install, calibrate, maintain, and operate a CPMS to monitor and 
record the activated carbon injection rate and taconite pellet 
production rate.
    (5) Maintain the carbon injection rate at or above the rate 
established by the correlation curve corresponding to the taconite 
pellet production rate. If the taconite pellet production rate drops 
below the minimum rate established in paragraph (n)(3) of this section, 
you must maintain the activated carbon injection rate at or above the 
rate established for the minimum taconite pellet production rate.
    (6) Keep records of the activated carbon injection rate and 
taconite pellet production rate for each hour of operation in order to 
demonstrate that the activated carbon injection rate remains in 
compliance with paragraph (n)(5) of this section.
    (7) Establish a new correlation curve at least twice per 5-year 
permit term.
0
15. Section 63.9636 is amended by revising paragraph (a) introductory 
text to read as follows:


Sec.  63.9636  How do I demonstrate continuous compliance with the 
operation and maintenance requirements that apply to me?

    (a) For each control device used to comply with an emission 
standard in Sec.  63.9590(a), you must demonstrate continuous 
compliance with the operation and maintenance requirements in Sec.  
63.9600(b) by completing the requirements of paragraphs (a)(1) through 
(4) of this section.
* * * * *


0
16. Section 63.9637 is amended by revising paragraph (a) to read as 
follows:


Sec.  63.9637  What other requirements must I meet to demonstrate 
continuous compliance?

    (a) Deviations. You must report each instance in which you did not 
meet each emission limitation in tables 1 through 3 to this subpart 
that applies to you. You also must report each instance in which you 
did not meet the work practice standards in Sec.  63.9591 and each 
instance in which you did not meet each operation and maintenance 
requirement in Sec.  63.9600 that applies to you. These instances are 
deviations from the emission limitations, work practice standards, and 
operation and maintenance requirements in this subpart. These 
deviations must be reported in accordance with the requirements in 
Sec.  63.9641.
* * * * *


0
17. Section 63.9640 is amended by adding paragraphs (f) and (g) to read 
as follows:


Sec.  63.9640  What notifications must I submit and when?

* * * * *
    (f) If you elect to use CEMS to demonstrate compliance with the 
mercury standards in table 2 to this subpart, you must submit a 
notification of intent to use CEMS at least one month prior to making 
the change. If you are currently using CEMS to demonstrate compliance 
with the mercury standards, you must submit a notification of intent to 
cease using CEMS to demonstrate compliance at least 180 days prior to 
making the change.
    (g) If you elect to use the mercury emissions averaging compliance 
option, you must submit a notification of intent at least 180 days 
prior to making the change. If you are currently using the mercury 
emissions averaging compliance option, you must submit a notification 
of intent to cease using emissions averaging at least 30 days prior to 
making the change.


0
18. Section 63.9641 is amended by:
0
a. Revising paragraph (b)(6);
0
b. Revising and republishing paragraph (b)(8);
0
c. Revising paragraphs (c), (e) and (f)(3); and
0
d. Adding paragraph (i).
    The revisions and additions read as follows:


Sec.  63.9641  What reports must I submit and when?

* * * * *
    (b) * * *
    (6) If there were no periods during which a continuous monitoring 
system (including a CPMS, COMS, or CEMS) was out-of-control as 
specified in Sec.  63.8(c)(7), then provide a statement that there were 
no periods during which a continuous monitoring system was out-of-
control during the reporting period.
* * * * *
    (8) On or before January 25, 2021, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, for each deviation from an emission limitation occurring at an 
affected source where you are using a continuous monitoring system 
(including a CPMS or COMS) to comply with the emission limitation in 
this subpart, you must include the information in paragraphs (b)(1) 
through (4) of this section and the information in paragraphs (b)(8)(i) 
through (xi) of this section. This includes periods of startup, 
shutdown, and malfunction. After January 25, 2021, for affected sources 
that commenced construction or reconstruction on or before September 
25, 2019, and after July 28, 2020, or upon start-up, which ever date is 
later, for affected sources that commenced construction or 
reconstruction after September 25, 2019, for each deviation from an 
emission limitation occurring at an affected source where you are using 
a continuous monitoring system (including a CPMS, COMS, or CEMS) to 
comply with the emission limitation in this subpart, you must include 
the information in paragraphs (b)(1) through

[[Page 16436]]

(4) of this section and the information in paragraphs (b)(8)(i) through 
(xi) of this section.
    (i) The date and time that each malfunction started and stopped.
    (ii) The start date, start time, and duration in hours (or minutes 
for COMS) that each continuous monitoring system was inoperative, 
except for zero (low-level) and high-level checks.
    (iii) The start date, start time, and duration that each continuous 
monitoring system was out-of-control, including the information in 
Sec.  63.8(c)(8).
    (iv) On or before January 25, 2021, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, for each affected source or equipment, the date and time that 
each deviation started and stopped, the cause of the deviation, and 
whether each deviation occurred during a period of startup, shutdown, 
or malfunction or during another period. After January 25, 2021, for 
affected sources that commenced construction or reconstruction on or 
before September 25, 2019, and after July 28, 2020, or upon start-up, 
which ever date is later, for affected sources that commenced 
construction or reconstruction after September 25, 2019, for each 
affected source or equipment, the date and time that each deviation 
started and stopped, the cause of the deviation, and whether each 
deviation occurred during a period of malfunction or during another 
period
    (v) The total duration of all deviations for each Continuous 
Monitoring System (CMS) during the reporting period, the total 
operating time in hours of the affected source during the reporting 
period, and the total duration as a percent of the total source 
operating time during that reporting period.
    (vi) On or before January 25, 2021, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, a breakdown of the total duration of the deviations during the 
reporting period including those that are due to startup, shutdown, 
control equipment problems, process problems, other known causes, and 
other unknown causes. After January 25, 2021, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, and after July 28, 2020, or upon start-up, which ever date is 
later, for affected sources that commenced construction or 
reconstruction after September 25, 2019, a breakdown of the total 
duration 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.
    (vii) The total duration of continuous monitoring system downtime 
for each continuous monitoring system during the reporting period, the 
total operating time in hours of the affected source during the 
reporting period, and the total duration of continuous monitoring 
system downtime as a percent of the total source operating time during 
the reporting period.
    (viii) A brief description of the process units.
    (ix) The monitoring equipment manufacturer and model number and the 
pollutant or parameter monitored.
    (x) The date of the latest continuous monitoring system 
certification or audit.
    (xi) A description of any changes in continuous monitoring systems, 
processes, or controls since the last reporting period.
    (c) Submitting compliance reports electronically. Beginning on 
January 25, 2021, submit all subsequent compliance reports to the EPA 
via CEDRI, which can be accessed through the EPA's Central Data 
Exchange (CDX) (https://cdx.epa.gov/). The EPA will make all the 
information submitted through CEDRI available to the public without 
further notice to you. Do not use CEDRI to submit information you claim 
as confidential business information (CBI). Anything submitted using 
CEDRI cannot later be claimed to be CBI. You must use the appropriate 
electronic report template on the CEDRI website (https://www.epa.gov/electronic-reporting-air-emissions/compliance-and-emissions-data-reporting-interface-cedri) for this subpart. The report must be 
submitted by the deadline specified in this subpart, regardless of the 
method in which the report is submitted. Although we do not expect 
persons to assert a claim of CBI, if persons wish to assert a CBI 
claim, submit a complete report, including information claimed to be 
CBI, to the EPA. The report must be generated using the appropriate 
form on the CEDRI website. Clearly mark the part or all of the 
information that you claim to be CBI. Information not marked as CBI may 
be authorized for public release without prior notice. Information 
marked as CBI will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2. Submit the file following the 
procedures in paragraph (c)(1) or (2) of this section. The same file 
with the CBI omitted must be submitted to the EPA via the EPA's CDX as 
described earlier in this paragraph (c). All CBI claims must be 
asserted at the time of submission. Furthermore, under CAA section 
114(c) emissions data is not entitled to confidential treatment, and 
EPA is required to make emissions data available to the public. Thus, 
emissions data will not be protected as CBI and will be made publicly 
available. On or before January 25, 2021, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, 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 submit an immediate startup, shutdown and 
malfunction report according to the requirements in Sec.  
63.10(d)(5)(ii). After January 25, 2021, for affected sources that 
commenced construction or reconstruction on or before September 25, 
2019, and after July 28, 2020, or upon start-up, which ever date is 
later, for affected sources that commenced construction or 
reconstruction after September 25, 2019, an immediate startup, 
shutdown, and malfunction report is not required.
    (1) The preferred method to receive CBI is for it to be transmitted 
electronically using email attachments, File Transfer Protocol, or 
other online file sharing services. Electronic submissions must be 
transmitted directly to the OAQPS CBI Office at the email address 
<a href="/cdn-cgi/l/email-protection#0f606e7e7f7c6c6d664f6a7f6e21686079"><span class="__cf_email__" data-cfemail="caa5abbbbab9a9a8a38aafbaabe4ada5bc">[email protected]</span></a>, and as described above, should include clear CBI 
markings and be flagged to the attention of the Taconite Iron Ore 
Processing Sector Lead. If assistance is needed with submitting large 
electronic files that exceed the file size limit for email attachments, 
and if you do not have your own file sharing service, please email 
<a href="/cdn-cgi/l/email-protection#2e414f5f5e5d4d4c476e4b5e4f00494158"><span class="__cf_email__" data-cfemail="315e50404142525358715441501f565e47">[email protected]</span></a> to request a file transfer link.
    (2) If you cannot transmit the file electronically, you may send 
CBI information through the postal service to the following address: 
U.S. EPA, Attn: OAQPS Document Control Officer and Taconite Iron Ore 
Processing Sector Lead, Mail Drop: C404-02, 109 T.W. Alexander Drive, 
P.O. Box 12055, RTP, NC 27711. The mailed CBI material should be double 
wrapped and clearly marked. Any CBI markings should not show through 
the outer envelope.
* * * * *
    (e) Immediate corrective action report. If you had three 
unsuccessful attempts of applying corrective action as described in 
Sec.  63.9634(l) on an emission unit or group of emission units, then 
you must submit an immediate corrective action report. Within 5 
calendar days after the third unsuccessful attempt at corrective 
action, you must submit to the Administrator a written report in

[[Page 16437]]

accordance with Sec.  63.9634(l)(3) and (4). This report must notify 
the Administrator that a deviation has occurred and document the types 
of corrective measures taken to address the problem that resulted in 
the deviation of established operating parameters and the resulting 
operating limits.
    (f) * * *
    (3) Confidential business information (CBI).
    (i) The EPA will make all the information submitted through CEDRI 
available to the public without further notice to you. Do not use CEDRI 
to submit information you claim as CBI. Although we do not expect 
persons to assert a claim of CBI, if you wish to assert a CBI claim for 
some of the information submitted under paragraph (f)(1) or (2) of this 
section, you must submit a complete file, including information claimed 
to be CBI, to the EPA.
    (ii) The file must be generated using the EPA's ERT or an alternate 
electronic file consistent with the XML schema listed on the EPA's ERT 
website.
    (iii) Clearly mark the part or all of the information that you 
claim to be CBI. Information not marked as CBI may be authorized for 
public release without prior notice. Information marked as CBI will not 
be disclosed except in accordance with procedures set forth in 40 CFR 
part 2.
    (iv) The preferred method to receive CBI is for it to be 
transmitted electronically using email attachments, File Transfer 
Protocol, or other online file sharing services. Electronic submissions 
must be transmitted directly to the OAQPS CBI Office at the email 
address <a href="/cdn-cgi/l/email-protection#234c4252535040414a634653420d444c55"><span class="__cf_email__" data-cfemail="f59a9484858696979cb5908594db929a83">[email protected]</span></a>, and as described above, should include clear 
CBI markings and be flagged to the attention of the Group Leader, 
Measurement Policy Group. If assistance is needed with submitting large 
electronic files that exceed the file size limit for email attachments, 
and if you do not have your own file sharing service, please email 
<a href="/cdn-cgi/l/email-protection#84ebe5f5f4f7e7e6edc4e1f4e5aae3ebf2"><span class="__cf_email__" data-cfemail="ddb2bcacadaebebfb49db8adbcf3bab2ab">[email protected]</span></a> to request a file transfer link.
    (v) If you cannot transmit the file electronically, you may send 
CBI information through the postal service to the following address: 
U.S. EPA, Attn: OAQPS Document Control Officer and Measurement Policy 
Group Lead, Mail Drop: C404-02, 109 T.W. Alexander Drive, P.O. Box 
12055, RTP, NC 27711. The mailed CBI material should be double wrapped 
and clearly marked. Any CBI markings should not show through the outer 
envelope.
    (vi) All CBI claims must be asserted at the time of submission. 
Anything submitted using CEDRI cannot later be claimed CBI. 
Furthermore, under CAA section 114(c), emissions data is not entitled 
to confidential treatment, and the EPA is required to make emissions 
data available to the public. Thus, emissions data will not be 
protected as CBI and will be made publicly available.
    (vii) You must submit the same file submitted to the CBI office 
with the CBI omitted to the EPA via the EPA's CDX as described in Sec.  
63.9(k).
* * * * *
    (i) Use of CEMS for mercury. If you use CEMS to demonstrate 
compliance with the mercury emissions limits in table 2 to this 
subpart, you must submit the results of the performance evaluation 
following the procedure specified in either paragraph (i)(1) or (2) of 
this section within 60 days after the date of completing each CEMS 
performance evaluation (as defined in Sec.  63.2).
    (1) For performance evaluations of continuous monitoring systems 
measuring relative accuracy test audit (RATA) pollutants that are 
supported by the EPA's ERT as listed on the EPA's ERT website at the 
time of the evaluation, you must submit the results of the performance 
evaluation to the EPA via the CEDRI. Performance evaluation data must 
be submitted in a file format generated through the use of the EPA's 
ERT or an alternate file format consistent with the XML schema listed 
on the EPA's ERT website. If you claim that some of the performance 
evaluation information being transmitted is CBI, you must submit a 
complete file generated through the use of the EPA's ERT or an 
alternate electronic file consistent with the XML schema listed on the 
EPA's ERT website, including information claimed to be CBI, on a 
compact disc, flash drive, or other commonly used electronic storage 
media to the EPA. The electronic media must be clearly marked as CBI 
and mailed to U.S. EPA/OAQPS/CORE CBI Office, Attention: Group Leader, 
Measurement Policy Group, MD C404-02, 4930 Old Page Rd., Durham, NC 
27703. The same ERT or alternate file with the CBI omitted must be 
submitted to the EPA via the EPA's CDX as described earlier in this 
section.
    (2) For any performance evaluations of continuous monitoring 
systems measuring RATA pollutants that are not supported by the EPA's 
ERT as listed on the ERT website at the time of the evaluation, you 
must submit the results of the performance evaluation to the 
Administrator at the appropriate address listed in Sec.  63.13.

0
19. Section 63.9642 is amended by:
0
a. Revising paragraph (b) introductory text; and
0
b. Adding paragraphs (b)(5), (d), (e) and (f).
    The revisions and additions read as follows:


Sec.  63.9642  What records must I keep?

* * * * *
    (b) For each COMS and CEMS, you must keep the records specified in 
paragraphs (b)(1) through (5) of this section.
* * * * *
    (5) If you use mercury CEMS to demonstrate compliance with the 
mercury emission standard in table 2 of the subpart in accordance with 
Sec.  63.9623(e), records of requests for alternatives to the relative 
accuracy test for CEMS as required in Sec.  63.8(f)(6)(i).
* * * * *
    (d) If you elect the mercury emissions averaging compliance 
alternative pursuant to Sec.  63.9623(d), you must keep a copy of the 
emission averaging implementation plan required in Sec.  63.9623(d)(2), 
records of the taconite pellet production rate for each furnace 
included in the averaging, and all calculations required under Sec.  
63.9634(m).
    (e) If you elect to adjust the activated carbon injection rate 
based on the taconite pellet production rate in accordance with the 
provisions in Sec.  63.9634(n), you must keep a copy of the activated 
carbon injection implementation plan and records of the taconite pellet 
production rate and activated carbon injection rate.
    (f) If you use CEMS to demonstrate compliance with the mercury 
emissions limits in table 2 to this subpart, you must keep records of 
the notifications required in Sec.  63.9642(f).

0
20. Section 63.9650 is revised to read as follows:


Sec.  63.9650  What parts of the General Provisions apply to me?

    Table 4 to this subpart shows which parts of the General Provisions 
in Sec. Sec.  63.1 through 63.16 apply to you.

0
21. Section 63.9652 is amended by adding definitions in alphabetical 
order for ``Activated carbon injection (ACI) system'', ``Dry sorbent 
injection (DSI) system'', and ``Electrostatic precipitator (ESP)'' to 
read as follows:


Sec.  63.9652  What definitions apply to this subpart?

* * * * *
    Activated carbon injection (ACI) system means an add-on air 
pollution control system in which activated carbon or brominated 
activated carbon is injected into the flue gas steam

[[Page 16438]]

upstream of a particulate matter control device to adsorb mercury in 
the exhaust stream. The absorbed mercury remains absorbed to the 
activated carbon and is collected in a primary or secondary particulate 
matter control device.
* * * * *
    Dry sorbent injection (DSI) system means an add-on air pollution 
control system that injects dry alkaline sorbent (dry injection) or 
sprays an alkaline sorbent (spray dryer) to react with and neutralize 
acid gas in the exhaust stream forming a dry powder material that is 
collected by a primary or secondary particulate matter control device.
* * * * *
    Electrostatic Precipitator (ESP) means a device that removes 
suspended particulate matter from flue exhaust by applying a high-
voltage electrostatic charge to the particles, which are then attracted 
to and collected on a grounded plate. In a dry ESP, the particles are 
dislodged from the plate by rapping and are collected in a hopper 
positioned below the plate. In a wet ESP, particulates are removed from 
the plate by washing with water.
* * * * *

0
22. Revise the table heading and introductory paragraph for table 1 to 
subpart RRRRR of part 63 to read as follows:

Table 1 to Subpart RRRRR of Part 63--Particulate Matter Emission Limits

    As required in Sec.  63.9590(a), you must comply with each 
applicable particulate matter emission limit in the following table:
* * * * *

0
22. Table 2 to subpart RRRRR is redesignated as table 4 to subpart 
RRRRR.

0
23. Add a new table 2 to subpart RRRRR to read as follows:

    Table 2 to Subpart RRRRR of Part 63--Mercury Emission Limits for
                           Indurating Furnaces
 [As required in Sec.   63.9590(a), you must comply with each applicable
             mercury emission limit in the following table:]
------------------------------------------------------------------------
                                    You must meet the following emission
             For . . .                          limits . . .
------------------------------------------------------------------------
1. Indurating furnaces constructed  Either:
 or reconstructed before May 15,    (1) Mercury emissions from each
 2023.                               furnace must not exceed 1.4 x 10-5
                                     lb/LT of taconite pellets produced,
                                     or
                                    (2) Production-weighted average
                                     mercury emissions for a group of
                                     indurating furnaces, calculated
                                     according to Equation 6 in Sec.
                                     63.9634(m)(3), must not exceed 1.3
                                     x 10-5 lb/LT.
2. Indurating furnaces constructed  Mercury emissions from each furnace
 or reconstructed on or after May    must not exceed 2.6 x 10-6 lb/LT.
 15, 2023.
------------------------------------------------------------------------


0
24. Add Table 3 to Subpart RRRRR to read as follows:

   Table 3 to Subpart RRRRR of Part 63--Hydrogen Chloride and Hydrogen
            Fluoride Emission Limits for Indurating Furnaces
 [As required in Sec.   63.9590(a), you must comply with each applicable
 hydrogen chloride and hydrogen fluoride emission limit in the following
                                 table:]
------------------------------------------------------------------------
                                    You must meet the following emission
             For . . .                          limits . . .
------------------------------------------------------------------------
1. Indurating furnaces constructed  Hydrogen chloride emissions must not
 or reconstructed before May 15,     exceed 4.6 x 10-2 lb/Long Ton of
 2023.                               taconite pellets produced.
                                    Hydrogen fluoride emissions must not
                                     exceed 1.2 x 10-2 lb/Long Ton of
                                     taconite pellets produced.
2. Indurating furnaces constructed  Hydrogen chloride emissions must not
 or reconstructed on or after May    exceed 4.4 x 10-4 lb/Long Ton of
 15, 2023.                           taconite pellets produced
                                    Hydrogen fluoride emissions must not
                                     exceed 3.3 x 10-4 lb/Long Ton of
                                     taconite pellets produced.
------------------------------------------------------------------------


0
25. Revise newly redesignated table 4 to subpart RRRRR to read as 
follows:

      Table 4 to Subpart RRRRR of Part 63--Applicability of General Provisions to Subpart RRRRR of Part 63
 [As required in Sec.   63.9650, you must comply with the requirements of the NESHAP General Provisions (40 CFR
                               part 63, subpart A) shown in the following table:]
----------------------------------------------------------------------------------------------------------------
                                                                Am I subject to this
             Citation                Summary of requirement         requirement?              Explanations
----------------------------------------------------------------------------------------------------------------
Sec.   63.1(a)(1)-(4)............  Applicability............  Yes.....................
Sec.   63.1(a)(5)................  [Reserved]...............  No......................
Sec.   63.1(a)(6)................  Applicability............  Yes.....................
Sec.   63.1(a)(7)-(9)............  [Reserved]...............  No......................
Sec.   63.1(a)(10)-(14)..........  Applicability............  Yes.....................
Sec.   63.1(b)(1)................  Initial Applicability      Yes.....................
                                    Determination.
Sec.   63.1(b)(2)................  [Reserved]...............  No......................
Sec.   63.1(b)(3)................  Initial Applicability      Yes.....................
                                    Determination.
Sec.   63.1(c)(1)-(2)............  Applicability After        Yes.....................
                                    Standard Established,
                                    Permit Requirements.

[[Page 16439]]

 
Sec.   63.1(c)(3)-(4)............  [Reserved]...............  No......................
Sec.   63.1(c)(5)................  Area Source Becomes Major  Yes.....................
Sec.   63.1(c)(6)................  Reclassification.........  Yes.....................
Sec.   63.1(d)...................  [Reserved]...............  No......................
Sec.   63.1(e)...................  Equivalency of Permit      Yes.....................
                                    Limits.
Sec.   63.2......................  Definitions..............  Yes.....................
Sec.   63.3(a)-(c)...............  Units and Abbreviations..  Yes.....................
Sec.   63.4(a)(1)-(2)............  Prohibited Activities....  Yes.....................
Sec.   63.4(a)(3)-(5)............  [Reserved]...............  No......................
Sec.   63.4(b)-(c)...............  Circumvention,             Yes.....................
                                    Fragmentation.
Sec.   63.5(a)(1)-(2)............  Construction/              Yes.....................
                                    Reconstruction,
                                    Applicability.
Sec.   63.5(b)(1)................  Construction/              Yes.....................
                                    Reconstruction,
                                    Applicability.
Sec.   63.5(b)(2)................  [Reserved]...............  No......................
Sec.   63.5(b)(3)-(4)............  Construction/              Yes.....................
                                    Reconstruction,
                                    Applicability.
Sec.   63.5(b)(5)................  [Reserved]...............  No......................
Sec.   63.5(b)(6)................  Applicability............  Yes.....................
Sec.   63.5(c)...................  [Reserved]...............  No......................
Sec.   63.5(d)(1)-(4)............  Application for Approval   Yes.....................
                                    of Construction or
                                    Reconstruction.
Sec.   63.5(e)...................  Approval of Construction   Yes.....................
                                    or Reconstruction.
Sec.   63.5(f)...................  Approval Based on State    Yes.....................
                                    Review.
Sec.   63.6(a)...................  Compliance with Standards  Yes.....................
                                    and Maintenance
                                    Requirements.
Sec.   63.6(b)(1)-(5)............  Compliance Dates for New/  Yes.....................
                                    Reconstructed Sources.
Sec.   63.6(b)(6)................  [Reserved]...............  No......................
Sec.   63.6(b)(7)................  Compliance Dates for New/  Yes.....................
                                    Reconstructed Sources.
Sec.   63.6(c)(1)-(2)............  Compliance Dates for       Yes.....................
                                    Existing Sources.
Sec.   63.6(c)(3)-(4)............  [Reserved]...............  No......................
Sec.   63.6(c)(5)................  Compliance Dates for       Yes.....................
                                    Existing Sources.
Sec.   63.6(d)...................  [Reserved]...............  No......................
Sec.   63.6(e)(1)(i).............  Operation and Maintenance  Yes, on or before the     See Sec.   63.9600(a)
                                    Requirements--General      compliance date           for general duty
                                    Duty to Minimize           specified in Sec.         requirement.
                                    Emissions.                 63.9600(a). No, after
                                                               the compliance date
                                                               specified in Sec.
                                                               63.9600(a).
Sec.   63.6(e)(1)(ii)............  Operation and Maintenance  No......................
                                    Requirements--Requiremen
                                    t to Correct Malfunction
                                    as Soon as Possible.
Sec.   63.6(e)(1)(iii)...........  Operation and Maintenance  Yes.....................
                                    Requirements--Enforceabi
                                    lity.
Sec.   63.6(e)(2)................  [Reserved]...............  No......................
Sec.   63.6(e)(3)................  Startup, Shutdown,         Yes, on or before the
                                    Malfunction (SSM) Plan.    compliance date
                                                               specified in Sec.
                                                               63.9610(c). No, after
                                                               the compliance date
                                                               specified in Sec.
                                                               63.9610(c).
Sec.   63.6(f)(1)................  SSM exemption............  No......................  See Sec.   63.9600(a).
Sec.   63.6(f)(2)-(3)............  Methods for Determining    Yes.....................
                                    Compliance.
Sec.   63.6(g)(1)-(3)............  Alternative Nonopacity     Yes.....................
                                    Standard.
Sec.   63.6(h), except (h)(1)....  Compliance with Opacity    No......................  Opacity limits in
                                    and Visible Emission                                 subpart RRRRR are
                                    (VE) Standards.                                      established as part of
                                                                                         performance testing in
                                                                                         order to set operating
                                                                                         limits for ESPs.
Sec.   63.6(h)(1)................  Compliance except during   No......................  See Sec.   63.9600(a).
                                    SSM.
Sec.   63.6(i)(1)-(14)...........  Extension of Compliance..  Yes.....................
Sec.   63.6(i)(15)...............  [Reserved]...............  No......................
Sec.   63.6(i)(16)...............  Extension of Compliance..  Yes.....................
Sec.   63.6(j)...................  Presidential Compliance    Yes.....................
                                    Exemption.
Sec.   63.7(a)(1)-(2)............  Applicability and          No......................  Subpart RRRRR specifies
                                    Performance Test Dates.                              performance test
                                                                                         applicability and
                                                                                         dates.
Sec.   63.7(a)(3)-(4)............  Performance Testing        Yes.....................
                                    Requirements.
Sec.   63.7(b)...................  Notification.............  Yes.....................
Sec.   63.7(c)...................  Quality Assurance/Test     Yes.....................
                                    Plan.

[[Page 16440]]

 
Sec.   63.7(d)...................  Testing Facilities.......  Yes.....................
Sec.   63.7(e)(1)................  Conduct of Performance     No......................  See Sec.   63.9621.
                                    Tests.
Sec.   63.7(e)(2)-(4)............  Conduct of Performance     Yes.....................
                                    Tests.
Sec.   63.7(f)...................  Alternative Test Method..  Yes.....................
Sec.   63.7(g)...................  Data Analysis............  Yes.....................  Except this subpart
                                                                                         specifies how and when
                                                                                         the performance test
                                                                                         results are reported.
Sec.   63.7(h)...................  Waiver of Tests..........  Yes.....................
Sec.   63.8(a)(1)-(2)............  Monitoring Requirements..  Yes.....................
Sec.   63.8(a)(3)................  [Reserved]...............  No......................
Sec.   63.8(a)(4)................  Additional Monitoring      No......................  Subpart RRRRR does not
                                    Requirements for Control                             require flares.
                                    Devices in Sec.   63.11.
Sec.   63.8(b)(1)-(3)............  Conduct of Monitoring....  Yes.....................
Sec.   63.8(c)(1)(i).............  Operation and Maintenance  Yes, on or before the     See Sec.   63.9632 for
                                    of CMS.                    compliance date           operation and
                                                               specified in Sec.         maintenance
                                                               63.9632(b)(4). No,        requirements for
                                                               after the compliance      monitoring. See Sec.
                                                               date specified in Sec.    63.9600(a) for general
                                                                63.9632(b)(4).           duty requirement.
Sec.   63.8(c)(1)(ii)............  Spare parts for CMS        Yes.....................
                                    Equipment.
Sec.   63.8(c)(1)(iii)...........  SSM Plan for CMS.........  Yes, on or before the
                                                               compliance date
                                                               specified in Sec.
                                                               63.9632(b)(4). No,
                                                               after the compliance
                                                               date specified in Sec.
                                                                63.9632(b)(4).
Sec.   63.8(c)(2)-(3)............  CMS Operation/Maintenance  Yes.....................
Sec.   63.8(c)(4)................  Frequency of Operation     No......................  Subpart RRRRR specifies
                                    for CMS.                                             requirements for
                                                                                         operation of CMS.
Sec.   63.8(c)(5)-(8)............  CMS Requirements.........  Yes.....................  CMS requirements in Sec.
                                                                                           63.8(c)(5) and (6)
                                                                                         apply only to COMS for
                                                                                         dry ESPs.
Sec.   63.8(d)(1)-(2)............  Monitoring Quality         Yes.....................
                                    Control.
Sec.   63.8(d)(3)................  Monitoring Quality         No......................  See Sec.
                                    Control.                                             63.9632(b)(5).
Sec.   63.8(e)...................  Performance Evaluation     Yes.....................
                                    for CMS.
Sec.   63.8(f)(1)-(5)............  Alternative Monitoring     Yes.....................
                                    Method.
Sec.   63.8(f)(6)................  Relative Accuracy Test     Yes.....................  Only if using continuous
                                    Alternative (RATA).                                  emission monitoring
                                                                                         systems to demonstrate
                                                                                         compliance with Table 2
                                                                                         to this subpart.
Sec.   63.8(g)(1)-(g)(4).........  Data Reduction...........  Yes.....................
Sec.   63.8(g)(5)................  Data That Cannot Be Used.  No......................  Subpart RRRRR specifies
                                                                                         data reduction
                                                                                         requirements.
Sec.   63.9......................  Notification Requirements  Yes.....................  Additional notifications
                                                                                         for CMS in Sec.
                                                                                         63.9(g) apply to COMS
                                                                                         for dry ESPs.
Sec.   63.9(k)...................  Electronic reporting       Yes.....................  Only as specified in
                                    procedures.                                          Sec.   63.9(j)
Sec.   63.10(a)..................  Recordkeeping and          Yes.....................
                                    Reporting, Applicability
                                    and General Information.
Sec.   63.10(b)(1)...............  General Recordkeeping      Yes.....................
                                    Requirements.
Sec.   63.10(b)(2)(i)............  Records of SSM...........  No......................  See Sec.   63.9642 for
                                                                                         recordkeeping when
                                                                                         there is a deviation
                                                                                         from a standard.
Sec.   63.10(b)(2)(ii)...........  Recordkeeping of Failures  No......................  See Sec.   63.9642 for
                                    to Meet a Standard.                                  recordkeeping of (1)
                                                                                         date, time and
                                                                                         duration; (2) listing
                                                                                         of affected source or
                                                                                         equipment, and an
                                                                                         estimate of the
                                                                                         quantity of each
                                                                                         regulated pollutant
                                                                                         emitted over the
                                                                                         standard; and (3)
                                                                                         actions to minimize
                                                                                         emissions and correct
                                                                                         the failure.
Sec.   63.10(b)(2)(iii)..........  Maintenance Records......  Yes.....................
Sec.   63.10(b)(2)(iv)...........  Actions Taken to Minimize  No......................
                                    Emissions During SSM.
Sec.   63.10(b)(2)(v)............  Actions Taken to Minimize  No......................
                                    Emissions During SSM.
Sec.   63.10(b)(2)(vi)...........  Recordkeeping for CMS      Yes.....................
                                    Malfunctions.
Sec.   63.10(b)(2)(vii)-(xii)....  Recordkeeping for CMS....  Yes.....................
Sec.   63.10(b)(2)(xiii).........  Records for Relative       No......................
                                    Accuracy Test.
Sec.   63.10(b)(2)(xiv)..........  Records for Notification.  Yes.....................
Sec.   63.10(b)(3)...............  Applicability              Yes.....................
                                    Determinations.

[[Page 16441]]

 
Sec.   63.10(c)(1)-(6)...........  Additional Recordkeeping   Yes.....................
                                    Requirements for Sources
                                    with CMS.
Sec.   63.10(c)(7)-(8)...........  Records of Excess          ........................  Subpart RRRRR specifies
                                    Emissions and Parameter                              recordkeeping
                                    Monitoring Exceedances                               requirements.
                                    for CMS.
Sec.   63.10(c)(9)...............  [Reserved]...............  No......................
Sec.   63.10(c)(10)-(14).........  CMS Recordkeeping........  Yes.....................
Sec.   63.10(c)(15)..............  Use of SSM Plan..........  No......................
Sec.   63.10(d)(1)-(2)...........  General Reporting          Yes.....................  Except this subpart
                                    Requirements.                                        specifies how and when
                                                                                         the performance test
                                                                                         results are reported.
Sec.   63.10(d)(3)...............  Reporting opacity or VE    No......................  Subpart RRRRR does not
                                    observations.                                        have opacity and VE
                                                                                         standards that require
                                                                                         the use of EPA Method 9
                                                                                         of appendix A-4 to 40
                                                                                         CFR part 60 or EPA
                                                                                         Method 22 of appendix A-
                                                                                         7 to 40 CFR part 60.
Sec.   63.10(d)(5)...............  SSM Reports..............  Yes, on or before the     See Sec.   63.9641 for
                                                               compliance date           malfunction reporting
                                                               specified in Sec.         requirements.
                                                               63.9641(b)(4). No,
                                                               after the compliance
                                                               date specified in Sec.
                                                                63.9641(b)(4).
Sec.   63.10(e)..................  Additional Reporting       Yes, except a breakdown   The electronic reporting
                                    Requirements.              of the total duration     template combines the
                                                               of excess emissions due   information from the
                                                               to startup/shutdown       summary report and
                                                               in63.10(e)(3)(vi)(I) is   excess emission report
                                                               not required and when     with the Subpart RRRRR
                                                               the summary report is     compliance report.
                                                               submitted through
                                                               CEDRI, the report is
                                                               not required to be
                                                               titled ``Summary Report-
                                                               Gaseous and Opacity
                                                               Excess Emission and
                                                               Continuous Monitoring
                                                               System Performance.''.
Sec.   63.10(f)..................  Waiver for Recordkeeping   Yes.....................
                                    or Reporting.
Sec.   63.11.....................  Control Device and Work    No......................  Subpart RRRRR does not
                                    Practice Requirements.                               require flares.
Sec.   63.12(a)-(c)..............  State Authority and        Yes.....................
                                    Delegations.
Sec.   63.13(a)-(c)..............  State/Regional Addresses.  Yes.....................
Sec.   63.14(a)-(t)..............  Incorporation by           Yes.....................
                                    Reference.
Sec.   63.15(a)-(b)..............  Availability of            Yes.....................
                                    Information and
                                    Confidentiality.
Sec.   63.16.....................  Performance Track          Yes.....................
                                    Provisions.
----------------------------------------------------------------------------------------------------------------


[FR Doc. 2024-02305 Filed 3-5-24; 8:45 am]
BILLING CODE 6560-50-P


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