observation concurrent with PM and/or PM less than 2.5 micrometers
(PM2.5) testing of EAF primary control devices.'' The
commenter stated that charging time is less than 1 minute to 3 minutes
per charge, and tapping is 4 to 6 minutes, so it is not surprising that
most of the time opacity was measured during melting and refining.
    However, we agree with the commenter that because the current EAF
NSPS rules in 40 CFR part 60, subparts AA and AAa only require opacity
measurements during melting and refining, the data obtained by the EPA
can be assumed to reflect only operation during melting and refining.
Therefore, while we are retaining 0 percent opacity during melting and
refining in the final rule as in the proposal, we are reverting back to
the opacity limit of 6 percent opacity for charging and tapping as in
the current rules in 40 CFR part 60, subparts AA, AAa.
    Additionally, opacity testing during charging, tapping, and
melting, and refining periods is required in the final rule. Opacity
tests during tapping, and melting and refining periods should be able
meet the minimum 6 minutes of total opacity testing required under EPA
Method 9 in 24 consecutive tests for 15 seconds each. However, we are
allowing a modification of EPA Method 9 for testing during charging
because of the potentially shorter time period that charging occurs. In
the final rule, we are allowing the EPA Method 9 testing during
charging to be determined from the average of 12 consecutive
observations recorded at 15-second intervals for a total of 3 minutes
of opacity testing.
    Comment: The commenter asserted that the EPA did not properly
evaluate the cost of compliance with 0 percent opacity for a source as
a result of modification.
    EPA Response: The commenter was not specific as to what type of
modification needed to be evaluated for its costs to comply with the
proposed opacity standards. A modification that triggers applicability
of an NSPS is a modification that increases emissions and meets the
requirements in 40 CFR 60.14. Without knowing which type of
modification is in question, it is difficult to compare the costs of
compliance and address the commenter's concern. A facility may be
adding another baghouse to accommodate increased production of the EAF.
In this case, the modification (additional baghouse) is outside of the
melt shop and, therefore, is not affected by the melt shop standard. If
a facility is modifying an EAF to increase production, pursuant to 40
CFR 60.14 (e), an increase in production rate of the existing EAF is
not considered a modification if that increase can be accomplished
without a capital expenditure on that facility. The partial roof canopy
determined to be BSER for the melt shop is a type of capture device
that can be added to any melt shop. However, the final rule does not
require that a partial roof canopy be installed to be in compliance
with the opacity standard. Affected sources can seek other methods to
achieve the melt shop opacity.
    Comment: In regard to canopy hood control costs, a commenter stated
the EPA did not examine advances in control technologies, process
operations, design or efficiency improvements, or other systems of
emission reduction, that are ``adequately demonstrated.'' Rather, the
EPA looked to a decades-old BID, concluded that ``[c]anopy hoods are a
common method of controlling fugitive EAF emissions,'' and assessed
costs for: adding a partial roof canopy (segmented canopy hood, closed
roof over furnace, open roof monitor elsewhere) to collect PM emissions
that might otherwise escape through the shops to achieve complete
control of melt shop fugitives.
    The commenter stated the EPA did not analyze whether canopy hoods
were used by the 19 facilities that recorded 0 percent opacity during
performance testing or were absent from the 9 facilities that recorded
the highest opacity during performance tests. The commenter claims that
this information was available to the EPA in the docket for the 40 CFR
part 63, subpart YYYYY NESHAP for EAF--the same docket that supplied
the majority of the performance test data the EPA used in this rule.
The commenter further asserted that the EPA's own review of

the survey responses in the 40 CFR part 60, subpart YYYYY docket in
June 2005 shows that the EPA knows that canopy hoods were used to
capture fugitive emissions from 32 of the 38 EAF described in the CAA
section 114 survey responses, and that the presence or absence of a
partial roof canopy did not determine whether the facilities responding
to the survey could achieve 0 percent opacity. Therefore, the EPA has
no basis to now conclude for purposes of demonstrating achievability
and cost effectiveness that the singular act of installing a partial
roof canopy will ``achieve complete control of melt shop fugitives.''
    A commenter stated the EPA's conclusion is also contradicted within
the Agency's cost analysis. In order to estimate how much PM is emitted
from a facility that emits 6 percent opacity, the EPA used the 1982 BID
[Electric Arc Furnaces and Argon-Oxygen Decarburization Vessels in
Steel Industry--Background Information for Proposed Standards.
Preliminary Draft. June 1982, Table 3-7 at 3-37; and the 1983 BID
(Electric Arc Furnaces and Argon-Oxygen Decarburization Vessels in
Steel Industry--Background Information for Proposed Standards. (EPA-
450/3-82-020a) July 1983; Table 3-7 at 3-37] to estimate that EAF emit
an average of 29 lb/ton of uncontrolled PM emissions. The EPA then
relied on the 1982 [and 1983] BID again to estimate that facilities
emitting 6 percent opacity captured 90 percent of those emissions using
a ``segmented canopy hood, closed roof over furnace, open roof monitor
elsewhere.'' This is the exact fugitive emission capture technology
that the EPA's Cost Analysis presumes facilities with greater than 0
percent opacity can install to achieve 0 percent opacity. In other
words, the EPA's Cost Analysis assumes that facilities with a
``segmented canopy hood, closed roof over furnace, open roof monitor
elsewhere'' are emitting 6 percent opacity and if those facilities
install a ``segmented canopy hood, closed roof over furnace, open roof
monitor elsewhere'' they will achieve 0 percent opacity. Commenter
stated because it is arbitrary and unreasonable to assume that
facilities will be able to achieve 0 percent opacity by doing nothing
more than install the same systems that facilities already have
installed without reaching 0 percent opacity, the EPA has failed to
provide a cost estimate rationally related to reduction of opacity from
6 percent to 0 percent.
    EPA Response: Canopy hoods have been in use for many years in many
industries and are still in use today. The costs to install a partial
roof canopy to enhance control of EAF melt shop fugitives was taken
from relatively recent rulemakings (2011 through 2018 \16\) for the
Ferroalloys industry, which also uses EAF. The 1984 EAF BID was used
only to estimate uncontrolled EAF shop emissions in the proposal
because there is no estimate available of uncontrolled emissions due to
the fact that most, if not all, EAF facilities, especially those
subject to the EAF NSPS subparts AA and AAa, have some type of control
of shop emissions, e.g., DEC systems; canopy hoods, side draft hoods,
and tapping hoods; partial or total enclosures; scavenger duct systems;
and building evacuation systems (72 FR 53818). Even if a total
uncontrolled melt shop could be found, it is not a typical source test
to measure emissions from a large opening such as a roof vent or an
industrial door, nor does the EPA generally have the resources to
perform such a test.
---------------------------------------------------------------------------

    \16\ See https://www.epa.gov/stationary-sources-air-pollution/ferromanganese-and-silicomanganese-production-national-emission for
information regarding Ferroalloys rules.
---------------------------------------------------------------------------

    If some EAF facilities with canopy hoods are not achieving 0
percent opacity, as the commenter alleges, it is likely because both
the NESHAP (40 CFR part 63, subpart YYYYY) and NSPS standards (40 CFR
part 60, subparts AA, AAa) currently only require 6 percent opacity
limits for EAF and AOD, and because the standard is higher, they are
only being designed to meet that standard. Regardless of the fact that
some EAF and AOD facilities may have been designed this way, they still
can be designed or modified to achieve 100 percent capture to ensure 0
percent opacity. The fact that some hoods have not been achieving 100
percent capture at some facilities is not proof that canopy hoods
cannot be used to do so for new, modified, or reconstructed sources.
The commenter fails to provide a technical basis for why canopy hoods
cannot be designed to achieve 0 percent melt shop opacity.
    Out of 31 EAF facilities in the EPA EAF dataset with opacity data,
13 facilities achieved 0.000 percent shop opacity. Two additional
facilities achieved 0.00 percent shop opacity, and another 4 facilities
achieved 0.0 percent, for a total of 19 facilities able to comply with
a 0 percent shop standard. Out of the total 31 facilities in the EPA
EAF data, only 1 facility had shop opacity greater than 1 percent as an
average of all runs in the test, with the average of all 31 facilities
at 0.14 percent opacity (a value that would round down to 0 percent
under the NSPS). See the ``Emissions Memorandum,'' discussed earlier in
this section, for more information about these data.
    The addition of a canopy hood or alteration of existing hoods to
achieve slightly better capture is within reach by a facility achieving
less than 1 percent opacity but greater than 0 percent. The scenario of
installation of a canopy hood in the melt shop is used in the cost
analysis to represent one method that is lower in cost and can be used
to achieve the standard of performance if an existing source that is
not currently achieving 0 percent melt shop opacity were to modify or
reconstruct and become an affected facility under 40 CFR 60, subpart
AAb.
    Comment: A commenter stated melt shop partitions of the size
necessary to meaningfully contain EAF emissions within the melt shop
are not feasible in many mills given other equipment and shop design,
including cranes. In particular, sizable partition walls are not
feasible at many EAF steel mills because they will interfere with
overhead cranes that transport scrap metal to the furnace. Similarly,
transfer ladles that are carried by crane to and from the furnace for
tapping molten metal would be blocked by partition walls.
    The commenter said for existing facilities that may trigger an NSPS
modification in the future, achieving 0 percent shop opacity would
require extensive re-engineering that would be costly and introduce
practical and worker safety concerns as well. For example, one [trade]
association member stated that 0 percent shop opacity could only be
achieved, if at all, with near total enclosure of the EAF and doubling
the flow rate of the emission control system. The commenter stated that
only very short (and therefore marginally effective) partition walls
could be installed above the crane because of the lack of space between
the crane and the roof. They also noted that such short partitions
deteriorated quickly due to the heat and other elements. Thus, to
increase the size and collection efficiency to meet a 0 percent opacity
requirement, the facility would have to raise the roof of the structure
at an undetermined cost (a cost that likely would trigger a ``major
modification''), and potentially enclose the entire monovent, which
would likely create worker safety and heat stress issues.
    The commenter added, facilities would have to increase the number
and volume of fans to the baghouse, as well as require new or
additional fans in the shop and additional baghouses because the
facility's current baghouses are operating at close to maximum
capacity. Moreover, for servicing, cranes have to

be moved to a different part of the melt shop due to the partitions
being so close to the top of the cranes. To achieve compliance,
existing facilities such as these also would have to enclose the large
openings in the casting area to prevent winds from blowing through the
shop or wall off the EAF operations. Neither option is feasible; melt
shops are typically long buildings with EAF, LMS, and casting in the
same structure.
    EPA Response: The cost analysis for new, modified, or reconstructed
EAF to achieve 0 percent opacity is based on a ``partial'' canopy hood
and not ``partition walls,'' as the commenter suggests, that would
interfere with overhead cranes. In regard to the comment that ``costly
and impractical re-engineering to achieve 0 percent shop opacity that
could only be achieved, if at all, with near total enclosure of the EAF
that doubles the flow rate of the emission control system,'' there are
19 EAF facilities in the EPA EAF dataset that demonstrated with data
from 2010 that they were capable of complying with a 0 percent melt
shop opacity standard (which we assumed was during melting and
refining) and, therefore, belie this concern. And because only 1
facility among the 31 facilities in the EPA EAF dataset had shop
opacity greater than 1 percent as an average of all runs in the test,
the addition of a canopy hood may be unnecessary and only alteration of
the operation of existing hoods may be needed to achieve slightly
better capture to achieve 0 percent melt shop opacity during melting
and refining. This shows that meeting a new NSPS standard of 0 percent
melt shop opacity during melting and refining is within reach by most
if not all existing EAF facilities, so is even more likely achievable
in any new facility.
    In actuality, it is not likely that all current EAF facilities in
the industry will need to comply with 40 CFR part 60, subpart AAb,
which would only be applicable to new EAF facilities or, for existing
facilities, if the result of any future modifications or reconstruction
increased emissions and met the provisions in 40 CFR 60.14 for
modifications and 40 CFR 60.15 for reconstruction, respectively.\17\
Whether or not the modification or reconstruction planned at the
facility would also trigger permitting requirements because it is a
``major'' modification under the permitting regulations is not relevant
to the EPA's determination of the BSER. Moreover, the EPA does not
agree that it is likely that the construction of the canopy will itself
be considered a major modification that triggers permitting
requirements. The issue here is whether to meet the revised limit an
existing source that modifies needs to raise the roof structure to
install equipment to meet the standard. The EPA response to this issue
is that it is not required to raise the roof structure so as to be able
to install equipment, and we have no knowledge (and the commenter has
not provided information showing) that raising the melt shop roof has
ever having been done to meet a lower opacity, such as 0 percent.
---------------------------------------------------------------------------

    \17\ Note that modifications pursuant to CAA section 111 need
not be ``major'' to trigger application of the NSPS. Rather, a
modification under CAA section 111(a)(4) is defined as a physical
change in, or change in the method of operation of, a stationary
source which results in any increase in emissions. See also 40 CFR
60.14.
---------------------------------------------------------------------------

3. What is the rationale for the final BSER determination and what is
the final standard of performance?
    We established in the proposal (87 FR 29717-29718) that the use of
a canopy hood above the crane rails, while not required to achieve 0
percent melt shop opacity during melting and refining, is a cost-
effective method that can be used to do so, with cost effectiveness
estimated at $1,700 per ton PM removed in $2022 for a medium-sized
facility, annual costs of the canopy, at $1.1 million per year, and
with PM reduction of 684 tpy at a medium facility achieving 0 percent
melt shop opacity during melting and refining and 6 percent during
charging and tapping, as compared to 6 percent opacity at all times.
Analyses performed for small and large EAF melt shops produced similar
cost-effectiveness values, at $1,800 per ton PM removed and $1,700 per
ton PM removed, respectively. The values of $1,800 per ton or less are
considered cost effective and, therefore, the use of additional canopy
hoods above the crane rails is considered BSER for melt shop opacity
for new EAF/AOD using this approach. (See section III.A.1.a of this
preamble).
    The performance data obtained by the EPA for 31 facilities show
that 13 facilities achieved 0 percent opacity during melting and
refining and the other 17 achieved very low values of opacity so that
the overall average melt shop opacity from all 31 facilities was 0.14
percent. Therefore, considering that the costs are achievable even
without the addition of a canopy hood, we conclude the 0 percent
opacity is the standard of performance that reflects the degree of
emission limitation achievable with application of the BSER for melting
and refining.
    We also concluded that full enclosure is not needed to achieve 0
percent melt shop opacity during melting and refining. The EPA
acknowledges that facilities need sufficient capture ventilation to
collect melt shop PM emitted as fugitives, but this does not
necessarily require a fully enclosed melt shop, as seen in the data
from EAF facilities in 2010 test reports obtained by the EPA where 0
percent opacity was achieved.
    Because we do not have sufficient data to show that 0 percent melt
shop opacity is achievable during charging and tapping to refute
industry's assertion that 0 percent melt shop opacity is not achievable
during charging and tapping, nor are these data likely available
anywhere else, the final rule retains the current 6 percent NSPS limit
for charging and tapping in 40 CFR part 60, subparts AA, AAa, and adds
to the final rule for 40 CFR part 60, subpart AAb a testing requirement
during these periods along with the requirement to test during melting
and refining that is already required for facilities in operation on or
before May 16, 2022. Note that the test method protocol for measuring
opacity during charging has been modified for the final rule, as
discussed in section V.B.1 of this preamble.
4. Are there any relevant energy impacts or nonair quality health and
environmental impacts of the selection of the final BSER for melt shop
opacity and, if so, how were the final emission limitations based on
the BSER affected?
    There are no relevant energy impacts or nonair quality health and
significant environmental impacts of the final BSER for melt shop
opacity. These issues are discussed in detail in sections V.A and V.B
of this preamble. No comments were received on these issues.

C. NSPS Requirements for Opacity From Control Devices and Dust Handling
for Electric Arc Furnaces and Argon-Oxygen Decarburization Vessels
Constructed After May 16, 2022

    We proposed to retain the BSER determinations for proper operation
of control devices and proper dust handling procedures from NSPS
subpart AAa in NSPS subpart AAb as well as the limitations of 3 percent
and 10 percent opacity limits from control devices and dust handling,
respectively. No comments were received on this subject. Similarly, we
are finalizing the requirement for opacity from control devices and
dust handling in NSPS subpart AAb, as proposed.

D. Startup, Shutdown, Malfunction Requirements for Electric Arc
Furnaces and Argon-Oxygen Decarburization Vessels Modified,
Reconstructed, or Constructed After May 16, 2022

    Consistent with Sierra Club v. EPA, 551 F.3d 1019 (D.C. Cir. 2008),
the EPA has established standards in 40 CFR 60 subpart AAb that apply
at all times. We also are finalizing in 40 CFR 60 subpart AAb specific
requirements at 40 CFR 60.272b(c) that override the general provisions
for SSM requirements. In finalizing the standards in this rule, the EPA
has taken into account startup and shutdown periods and, for the
reasons explained in section IV.D.2 of this preamble has not finalized
alternate standards for those periods.
    Periods of startup, normal operations, and shutdown are all
predictable and routine aspects of a source's operations. Malfunctions,
in contrast, are neither predictable nor routine. Instead, they are, by
definition, sudden, infrequent, and not reasonably preventable failures
of emissions control, process, or monitoring equipment (40 CFR 60.2).
The EPA interprets CAA section 111 as not requiring emissions that
occur during periods of malfunction to be factored into development of
CAA section 111 standards. Nothing in CAA section 111 or in case law
requires that the EPA consider malfunctions when determining what
standards of performance reflect the degree of emission limitation
achievable through ``the application of the best system of emission
reduction'' that the EPA determines is adequately demonstrated. While
the EPA accounts for variability in setting emissions standards,
nothing in CAA section 111 requires the Agency to consider malfunctions
as part of that analysis. The EPA is not required to treat a
malfunction in the same manner as the type of variation in performance
that occurs during routine operations of a source. A malfunction is a
failure of the source to perform in a ``normal or usual manner'' and no
statutory language compels the EPA to consider such events in setting
CAA section 111 standards of performance. The EPA's approach to
malfunctions in the analogous circumstances (setting ``achievable''
standards under CAA section 112) has been upheld as reasonable by the
D.C. Circuit in U.S. Sugar Corp. v. EPA, 830 F.3d 579, 606-610 (2016).
1. What did we propose as the BSER determination and standard of
performance?
    Consistent with Sierra Club v. EPA, 551 F.3d 1019 (D.C. Cir. 2008),
the EPA proposed that the PM and opacity standards in 40 CFR subpart
AAb apply at all times. We also proposed in 40 CFR part 60, subpart AAb
specific requirements at 40 CFR 60.272b(c) that override the general
provisions exemptions during SSM periods.
2. What significant comments did we receive and what are our responses?
    Comment: A commenter asserted that the EPA must provide work
practice standards if the EPA removes SSM exemptions. Subjecting SSM
periods to the same limit as those during normal operations was not
adequately demonstrated as required per CAA section 111(a)(1) and was
not provided in the docket prior to promulgation as per CAA section
307(d). The dataset of stack tests from 33 facilities did not include
adequate testing to demonstrate that SSM periods consistently met the
limits proposed in 40 CFR part 60, subpart AAb. These stack tests were
not conducted during SSM periods, and as such could not provide a basis
for concluding that emissions during shutdown and startup could comply
with the proposed limits. The commenter asserts that, if the EPA cannot
show that compliance with a numerical limit was adequately demonstrated
during periods of SSM, and provide that data in the record, then the
EPA does not have the legal authority under CAA section 111 to subject
those emissions to such a standard.
    EPA Response: Consistent with Sierra Club v. EPA, this action will
ensure that the PM and opacity standards in EAF NSPS 40 CFR 60, subpart
AAb apply at all times, including during periods of startup and
shutdown. Because Sierra Club v. EPA established that emissions
standards or limitations must be continuous in nature, the EPA must
determine what standard will apply during periods of SSM. Moreover, CAA
section 111(h)(1) provides that the EPA may only provide for work
practice standards when the Administrator determines that it is not
feasible to prescribe or enforce a numerical work practice standard. We
have determined that the numerical standards in EAF NSPS 40 CFR 60
subpart AAb are appropriate as EAF and AOD facilities can comply with
the standards during startup and shutdown because the control devices
are the same during startup and shutdown as in normal operation and
would provide the same protection to PM emissions, both for PM from the
control devices as well as opacity from melt shop, control devices, and
dust handling. In regard to the 0 percent melt shop opacity standard,
this standard in 40 CFR part 60, subpart AAb only applies during
melting and refining; startup or shutdown does not fall under the
operational description of melting and refining. A opacity standard of
6 percent would apply at all other times.
    While commenters argue that the EPA must provide work practice
standards, the commenters have not provided information showing that
compliance with the numerical emission limitations is not possible
during startup and shutdown events and that, therefore, the EPA's
determination to apply the PM and opacity standards at all times would
be inappropriate. In addition to the standards applying at all times,
sources will need to comply with the CAA section 111 general
provisions, which include ``general duty'' requirements in 40 CFR
60.11(d) to operate ``in a manner consistent with good air pollution
control practice for minimizing emissions.'' These provisions apply at
all times, including during startup and shutdown, as well as during
malfunctions.
    Comment: A commenter stated if a 0 percent opacity standard for
melt shop emissions at all times was implemented, the EPA must exclude
periods of malfunctions and upset conditions. The commenter explained
that malfunctions have occurred during the melting and casting
operations that required extraordinary measures for corrective action,
such as a ``breakout.'' In an extremely dangerous situation, breakouts
occurred when molten steel escaped from one or more mold strands at the
caster or during casting. The commenter stated after a breakout and
subsequent corrective action, emissions were generated and may exit the
melt shop, and those emissions should not be considered in determining
compliance with the 0 percent opacity melt shop requirement. The
commenter said the EPA's proposed approach lacked an understanding of
the significant dangers, risks, and related emissions associated with
``breakouts'' and other malfunction events that occur during the
steelmaking processes, and the EPA should reconsider the 0 percent melt
shop opacity standard.
    EPA Response: The EPA disagrees with the commenter that emissions
during a malfunction are not appropriately subject to the standard.
Malfunctions that cause exceedances of any part of a rule are
considered a violation under the NSPS and are a compliance issue that
is relegated to the EPA's enforcement office. Facilities should
document the circumstances of the malfunction so as to be able to
discuss the special circumstances of the

event with the EPA's enforcement officer. It is not the purpose of the
BSER to take into account unpredictable, sudden, infrequent events such
as what is described by the commenter. We also note that casting is not
part of the EAF NSPS source category.

E. Testing and Monitoring Requirements for Electric Arc Furnaces and
Argon-Oxygen Decarburization Vessels

1. What did we propose for testing and monitoring?
    From the EPA review of the current NSPS's testing and monitoring
requirements in 40 CFR part 60, subpart AAa, we evaluated and
determined the testing, monitoring, recordkeeping and reporting
requirements needed to be clarified and revised'' to ensure compliance
with the emission standards, considering that the NSPS reflect BSER
under conditions of proper operation and maintenance. Consequently, we
proposed changes to testing and monitoring in 40 CFR part 60, subparts
AA and AAa, and also incorporated some of these requirements along with
additional requirements into new 40 CFR part 60, subpart AAb.
    Specifically, we proposed amendments to clarify, correct, or refine
the rule requirements to enhance compliance and enforcement with 40 CFR
part 60, sections 60.271 and 60.271a ``Definitions'', 60.272 and
60.272a ``Standard for particulate matter'', 60.273 and 60.273a
``Emission monitoring'', 60.274a ``Monitoring of operations'', 60.275a
``Test methods and procedures'', and 60.276a ``Recordkeeping and
reporting requirements.''
    In addition, we proposed that sources complying with 40 CFR part
60, subpart AAb would be required to perform compliance testing every 5
years after the initial testing performed upon startup, as required
under 40 CFR 60.8. This requirement for periodic testing already is
required in many of the permits for existing EAF in both the EPA's EAF
dataset and in the industry, and is a standard requirement for testing
of other sources of PM emissions in many other industrial sectors.
    We also solicited in the proposal for comments or data and other
relevant information on whether the EPA should change the allotted time
to both find and fix the cause of a BLDS alarm from 3 hours to a longer
timeframe (e.g., 24 hours as in other rules), or some other duration.
2. What significant comments did we receive on testing and monitoring
and what are our responses?
    Comment: The commenter said facilities should be allowed 24 hours
to respond to BLDS alarms and to complete the response as soon as
practical in 40 CFR part 60, subparts AA, AAa, and AAb. The commenter
disagreed with the proposed 40 CFR part 60, subpart AAb provisions that
would require facilities to determine the cause of all BLDS alarms
within 1 hour and alleviate the cause of the alarm within 3 hours by
taking the necessary response action. The commenter recommended the EPA
adopt a 24-hour timeframe to initiate corrective action and to require
that response actions be completed as soon as practicable. This
approach would recognize the practical realities in identifying and
responding to BLDS alarms. The commenter added that this approach is
the same as that used in the Integrated Iron and Steel NESHAP, and is
consistent with 40 CFR part 63, subparts X (NESHAP for Secondary Lead
Smelting), DDD (NESHAP for Mineral Wool Production), EEE (NESHAP from
Hazardous Waste Combustors), MMM (NESHAP for Pesticide Active
Ingredient Production), RRR (NESHAP for Secondary Aluminum Production),
and TTT (NESHAP for Primary Lead Smelting). The commenter said there
was no justification for the proposal to be different from other
existing rules. The commenter added that the proposed 3-hour time
period was arbitrary and ignored the numerous scenarios in which it can
take longer than 3 hours to identify and fix the cause of an alarm.
Allowing facilities 24 hours to identify the cause and requiring
facilities to alleviate the cause of the alarm ``as soon as
practicable'' is more practical, particularly where many baghouse
compartments must be inspected to determine the cause of an alarm.
    The commenter noted that there are situations in which more than 3
hours is needed to respond to a BLDS alarm and address its cause.
Because many mills calibrate their BLDS to be very sensitive, the
likelihood that a BLDS alarm will be falsely triggered is increased.
The commenter included the following examples of situations in which
false alarms can occur:
     Weather. BLDS alarms will occasionally trigger during a
heavy downpour or when there are significant changes in temperature or
humidity.
     Bag Cleaning Cycle. BLDS alarm may trigger at the end of
the baghouse cleaning cycle due to the temporary absence of dust in the
bags.
     New Bag Start. BLDS alarms can be triggered following a
replacement of some or all of the bags in the baghouse.
     Systems Checks/Testing. Some facilities may run systems
checks on their BLDS that cause the system to alarm. For example, a
facility may check the sensitivity of a BLDS by introducing a handful
of flour into a port upstream from the probe. Facilities also evaluate
and optimize their BLDS performance through drift checks, response
tests, calibration exercises, and other quality assurance procedures.
Some of these procedures require the alarm to be triggered in order to
test performance, but in other instances the BLDS alarm may be
inadvertently triggered during testing.
     Electrical Malfunctions. As BLDS detection is based on
contact electrification, alarms can be triggered due to electrical
surges impacting the sensors, processing electronics, or the
connections between the sensor and processing electronics. These surges
can either be environmental (lightning) or from variations/malfunctions
in the BLDS system, its software, or its power source. Additionally,
the abrasive environment in the baghouse duct can deteriorate the BLDS
probe, probe housing, and housing insulation, which can cause an
increase in malfunctions. BLDS alarms may be triggered during temporary
power lapses or brief connectivity issues between the sensor and the
processing electrics, or between the processing electronics and the
system output/alarm. The BLDS can experience brief mechanical or
software glitches/errors, including with respect to the sensor's signal
amplification or with the configuration of the processing electronics.
     Repair/Maintenance. Some baghouse repair and maintenance
activities may be conducted while the baghouse is in operation. In some
of these cases, proper inspection and repair requires the baghouse to
be operating in order to observe and repair malfunctions/maintenance
issues. Often these activities are coordinated with a baghouse operator
observing the BLDS readout in real time in order to identify the cause
of an earlier alarm or to proactively identify maintenance or
performance issues. Baghouse repair and maintenance activities
sometimes must be conducted when the baghouse is operating because the
repair/maintenance is urgently needed, and it is infeasible to quickly
shut down the baghouse. These activities will cause BLDS alarms to
trigger. Work on baghouse compartments and conveyances can introduce
particulates into the system or dislodge caked or

accumulated dust which triggers alarms. Sounding of BLDS alarms also
can be caused by maintenance and repair activities conducted when the
baghouse is not operating. These activities can introduce foreign
material or dislodge accumulations of material from ducts, conveyances,
access panels, joints, and other components of the system upstream from
the probe. Then when the baghouse is restarted, the newly introduced or
dislodged material can cause the BLDS alarm to be triggered.
    The commenter pointed out that it is possible for a baghouse to
operate within its emission and opacity limits even if the cause of a
BLDS alarm is not identified and corrective measures taken. For
example, if a broken bag in a compartment causes an alarm, the
compartment can be isolated and shut down without affecting the rest of
the baghouse. The commenter noted that determining the cause of the
alarm often requires operators to undertake a multi-step
troubleshooting process of elimination requiring multiple rounds of
physical inspections and diagnostic efforts. This process of
elimination often requires more than 3 hours to complete. The process
can be very time-consuming, particularly when the BLDS alarm lasts only
a short time. Identifying the cause of a brief BLDS alarm, the
commenter said, can be very difficult and sometimes proves impossible.
Some baghouses in the EAF industry have 25 or more compartments housing
5,000 or more individual bags. Some mills do not have BLDS with
detection capability in each separate compartment because the baghouse
design does not allow for such monitoring (e.g., multiple compartments
sharing common exit plenum). In these instances, mills must continue
running and sequentially isolate compartments to determine which
compartment may have caused the BLDS alarm. Facilities must then
physically examine the compartment(s), which may contain 150 or more
individual bags. If a bag has a significant rupture or has been
dislodged, the cause of the alarm will likely be readily apparent.
However, some alarms can be triggered by extremely small holes in bags
and, in these cases, finding the leak by physical inspection can take a
long time.
    The commenter said that EAF mills can have difficulty responding to
multiple, intermittent alarms of short duration. The commenter noted
that EAF facilities record the alarm as resolved where investigation
shows no evidence of a bag leak. While the facility may be able to
respond to each separate alarm in under 3 hours, the commenter said
they are aware of one instance in which an enforcement authority
determined the company was in violation of the 3-hour response
requirement because the total time the facility spent responding to
each of the separate intermittent alarms exceeded 3 hours. The
commenter said the enforcement authority misinterpreted the 3-hour
response requirement. This example was provided to show how a 3-hour
response requirement presents a compliance risk even when individual
responses are completed within the 3-hour window. The commenter
recommended the following additions be made to 40 CFR 60.273(f) in all
three rules in regard to the leak monitors to clarify false alarm
situations.
    The commenter recommended adding to the requirements in 40 CFR
60.273(f)), 60.273a(f)), and 60.273b(f)) that begin with:
``Establishing to the extent acceptable by the delegated authority that
the alarm was a false alarm and not caused by a bag leak or other
malfunction that could reasonably result in excess PM emissions,'' the
phrase ``in which case alarms due to the monitor malfunctioning are not
subject to the [24-hour] response action requirement, as long as the
[leak] monitor malfunction is timely corrected.''
    The commenter recommended adding to the requirements in 40 CFR
60.273(f)), 60.273a(f)), and 60.273b(f)) that begin with: ``Shutting
down the process producing the PM emissions,'' the phrase ``provided
that shutting down the process unit is not required if an operator
reasonably believes repetitive alarms are the result of a [leak]
monitor malfunction, and the monitor malfunction is timely repaired.''
    EPA Response: We appreciate the details provided by the commenters
to explain the reasons why a 24-hour response to BLDS alarms is
warranted based on technical issues that EAF facility operators face
and also why a 24-hour response is justified based on other similar
rules that allow a 24-hour response. In light of the rationale
provided, we are including the 24-hour response in the revisions to 40
CFR part 60, subparts AA, AAa, and AAb, effective upon promulgation.
    In regard to the specific language the commenter suggests including
in the rules in 40 CFR 60.273(f)), 60.273a(f)), and 60.273b(f)), the
list of potential response actions are not to be taken as exclusive,
i.e., the responses listed have the caveat that ``response actions may
include, but are not limited to, the following, etc.'' The commenter's
suggested changes for 40 CFR 60.273(f) in all 3 rules are redundant
within the existing and proposed rules because the phrase ``not caused
by . . . . . other malfunction that could reasonably result in excess
PM emissions'' already covers leak monitor malfunction. This is the
same issue for 40 CFR 60.273(f) in all 3 rules, where a shutdown is
just one option for a response action and not a required action. In all
3 rules in 40 CFR 60.273(f), fixing the leak monitor is the appropriate
response action if that is determined to be the cause of the alarm.
However, along with changing the response time to 24 hours, we have
added a specific item in all three EAF rules in 40 CFR 60.273(f) to
make it clear that leak monitor malfunction could be the cause, as
follows: ``Establishing to the extent acceptable by the delegated
authority that the alarm was a false alarm caused by a malfunctioning
monitor and not caused by excess PM emissions.''
    Comment: A commenter asserted that the current compliance
demonstration requirements using the fan amperage and damper position
monitoring in 40 CFR part 60, subparts AA, AAa are the best methods for
assuring compliance with the melt shop NSPS standards. A commenter
asserted that the existing fan amperage and damper position monitoring
in combination with opacity observations are the best methods of
assuring compliance with the NSPS standards for the melt shop. The
commenter opposed the proposed new monitoring requirements for 40 CFR
part 60, subparts AA and AAa that included:
     Installation of BLDS on all baghouses, including multi-
stack baghouses;
     Monitoring and operational restriction for furnace static
pressure monitoring based on 15-minute averages on all EAF;
     Monitoring and operational restriction for volumetric flow
rate or static pressure at each separately-ducted hood, based on 15-
minute averages on all EAF;
     Removal of the option for monitoring and operational
restriction for fan amps;
     Adding inspections and maintenance requirements for holes
or other openings in the melt shop building; and
     Mandate for shop opacity observations to be made during
charging and tapping or during the period of the heat cycle that
generates the greatest uncaptured emissions.
    The commenter considered these new monitoring requirements to be
unnecessary, expensive, and, in some cases, impractical. The commenter
said the existing monitoring requirements in 40 CFR part 60, subparts
AA and AAa

are adequate for demonstrating compliance with the standards. The
commenter stated that the existing fan amperage and damper position
monitoring have worked efficiently and effectively for many years and
the proposed new monitoring would be less effective and would impose
``. . . extreme technical and engineering complications'' on EAF
plants.
    Similarly, the commenter urged the EPA to keep the current
requirement in 40 CFR part 60, subparts AA, AAa for monitoring fan
amperage in place, because they said this parameter directly correlates
to the air flow to the control device, via the fan curve, unique to
each site.
    EPA Response: The responses to BLDS monitoring requirements, damper
position, fan amperage, furnace static pressure, melt shop inspection,
melt shop opacity, and volumetric flow and static pressure follow here.
     BLDS Response. We proposed the BLDS monitoring requirement
for all baghouses in 40 CFR part 60, subparts AA, AAa, and AAb because
BLDS provides better information about EAF baghouse operation and
compliance assurance for the PM emission and stack opacity limits than
what is currently required in 40 CFR part 60, subparts AA and AAa, and
because BLDS monitoring at all baghouses is technically feasible.
Currently, as an alternative to COMs, single-stack baghouses are
required to install a BLDS and perform EPA Method 9 visible emissions
at the stack, whereas modular, multi-stack, negative-pressure or
positive-pressure fabric filters are only required to conduct EPA
Method 9 visible emissions monitoring. We agree with the commenter that
the proposed change to require all types of baghouses to have BLDS
should not be made as a correction in 40 CFR part 60, subparts AA and
AAa, nor included in 40 CFR part 60, subpart AAb for all types of
baghouses. Therefore, because using BLDS at all baghouses would involve
the purchase of equipment not currently installed at facilities not
using single-stack baghouses, this requirement is not included in the
final rules for 40 CFR part 60, subparts AA and AAa. For 40 CFR part
60, subpart AAb, because for existing facilities that modify or
reconstruct, requiring BLDS at baghouses other than those with single
stacks would involve the purchase of equipment not currently installed
at these facilities, the BLDS requirement is included in the final rule
for 40 CFR part 60, subpart AAb only for single stack baghouses. For
new sources, the BLDS requirement is included in the final rule for 40
CFR part 60, subpart AAb, only for single stack baghouses because using
BLDS on multi-stack baghouses is not demonstrated in the EAF industry
due to the high capital cost. Multi-stack baghouses in the EAF industry
have vents rather than stacks, are operated at positive pressure, and
not amenable to leak detection systems.
     Damper Position Response. We proposed changes to the
monitoring frequency of damper position in 40 CFR part 60, subparts AA
and AAa, and included these proposed changes in 40 CFR part 60, subpart
AAb, because of the variability of this parameter during a furnace
cycle. As damper position is expected to change during the heat cycle,
a once-per-shift monitoring and recordkeeping event fails to provide
both the facility and regulatory agencies with the ability to determine
if the emissions capture system is being properly operated. Damper
position records are intended to be used as a way to evaluate how the
total flow (using amperage as surrogate for flow) is partitioned
between the separately ducted hoods. Therefore, increasing the
recording of damper position provides a more accurate assessment of the
capture system throughout a heat cycle. Facilities are already required
to record all damper positions during performance testing to
demonstrate compliance pursuant to 40 CFR 60.274(c) and 60.274a(c). We
disagree with the commenter that this change should not be made as a
correction. Therefore, for the reasons explained at proposal, the final
rules for 40 CFR part 60, subparts AA, AAa, and AAb include the
requirement for damper position recording and frequency during
operation in a manner and frequency consistent with damper position
records during the initial or most recent performance test
demonstrating compliance with applicable PM standards; and for 40 CFR
part 60, subpart AAb, only if damper position data were recorded
throughout a complete heat cycle. See 40 CFR 60.274(c)(1) and (i)(5),
60. 274a(c)(1) and (h)(5), and 60.274b(c)(1) and (h)(5). Compliance
with this clarified aspect of the rule is required 180 days from the
effective date of the final rule amendments for facilities complying
with 40 CFR part 60, subparts AA and AAa, the same as the requirement
for electronic reporting; and no later than the effective date of the
final rule or upon startup, whichever is later, for facilities subject
to 40 CFR part 60, subpart AAb.
     Fan Amperage Response. The EPA proposed deleting the
monitoring of fan amps on a once-per-shift basis as a surrogate for
volumetric flow from at 40 CFR 60.274(b)/60.274a(b) for 40 CFR part 60,
subparts AA and AAa due to the increased use of variable speed fans in
the industry. Based on comments provided in response to the proposed
change, the EPA agrees with the commenter that fan amperage monitoring
should be able to be used as a surrogate for volumetric flow. However,
the EPA believes this surrogate can only be allowed under some
conditions. To maintain consistency with the original intent of the
requirement to record fan amperage in 40 CFR part 60, subpart AAa, in
the final rules for 40 CFR part 60, subparts AA, AAa, and AAb, fan
amperage monitoring can be used as a surrogate for volumetric flow when
recorded on a more frequent basis than once-per-shift. The EPA is
promulgating for 40 CFR part 60, subparts AA, AAa, and AAb, the
requirement for monitoring and recording of fan amperage as frequently
as damper position measurement, i.e., in a manner and frequency
consistent with damper position records during the initial or most
recent performance test demonstrating compliance with applicable PM
standards so that the amperage data provide information that is
proportional to volumetric flow in 40 CFR 60.274(c))1) and (i)(5);
60.274(c)(1) and (h)(5); and 60.274b(c)(1)(h)(5). Compliance with this
clarified aspect of the rule is required 180 days from the effective
date of the final rule amendments for facilities complying with 40 CFR
part 60, subparts AA and AAa, the same as the requirement for
electronic reporting and no later than the effective date of the final
rule or upon startup, whichever is later, for facilities subject to 40
CFR part 60, subpart AAb.
     Furnace Static Pressure Response. We proposed the
requirement for monitoring and operational restriction for furnace
static pressure monitoring for 40 CFR part 60, subparts AA, AAa, and
AAb based on 15-minute averages on all EAF because it provides better
information about emissions capture at the EAF and compliance assurance
with melt shop opacity requirements at 40 CFR 60.272(a)(3),
60.272a(a)(3), and 40 CFR 60.272b(a)(3) than what is currently required
in 40 CFR part 60, subparts AA and AAa. Currently, a furnace static
pressure monitoring device is not required if the facility conducts
daily shop opacity readings. If a facility elects to use furnace static
pressure monitoring for compliance, furnace static pressure is only
monitored once per shift in 40 CFR part 60, subparts AA and AAa (see 40
CFR 60.273(d)/60.273a(d) and 40 CFR 60.273(d)/60.274a(b)). The EPA
proposed

requiring continuous monitoring of furnace static pressure because it
would provide information about capture at the EAF on a more frequent
basis and because many facilities already use this equipment. Because
using this monitoring method/compliance option would involve the
purchase of equipment not currently available or installed at all
subject facilities, we agree with the commenter that this change should
not be made as a correction nor included in 40 CFR part 60, subparts
AA, AAa, and AAb. Therefore, this requirement for 40 CFR part 60,
subparts AA, AAa, and AAb is not included in the final rules.
    In response to comments regarding proposed averaging periods of 15
minutes for furnace static pressure, the EPA has modified the averaging
period language in the final rule for 40 CFR part 60, subparts AA, AAa,
and AAb (40 CFR 60.274(f), 60.274a(f), and 60.274b(f)) to be ``no
greater than 15 minutes.'' This modification allows greater flexibility
for establishing monitoring setpoints to capture the variability during
short periods that are much less than 15 minutes.
     Melt Shop Inspection Response. We proposed a clarification
that the melt shop be inspected for holes or other openings that would
allow particulate matter to escape for 40 CFR part 60, subparts AA,
AAa, and included in 40 CFR part 60, AAb, because this procedure
provides compliance assurance with melt shop opacity requirements, and
is better than what is currently required at 40 CFR 60.272(a)(3)/
60.272a(a)(3). Currently, inspections are required for equipment
important to the performance of the capture system at 40 CFR 60.274(e)/
60.274a(d), which specifies that inspections must include observations
of physical appearance of the equipment. We disagree with the commenter
that changes to 40 CFR part 60, subparts AA and AAa, should not be made
as a correction because we understand that the melt shop building
itself acts as a portion of the capture system particularly during
charging and tapping. Since this inspection would not involve the
purchase of equipment not currently available or installed at the
facility and arguably is already addressed under the current
requirement for inspections, the clarification that inspection for
holes or other openings in the melt shop building is part of the
capture system inspection is included in the final rules for 40 CFR
part 60, subparts AA, AAa, and AAb. Compliance with this clarified
aspect of the rule is required 180 days from the effective date of the
final rule amendments for facilities complying with 40 CFR part 60,
subparts AA and AAa, the same as the requirement for electronic
reporting and no later than the effective date of the final rule or
upon startup, whichever is later, for facilities subject to 40 CFR part
60, subpart AAb.
     Melt Shop Opacity Response. We proposed the clarification
that melt shop opacity observations for 40 CFR part 60, subparts AA and
AAa must be made during charging and tapping or during the period of
the heat cycle that generates the greatest uncaptured emissions for 40
CFR part 60, subparts AA and AAa because this requirement provides
better information about EAF and AOD capture system performance and
compliance assurance with melt shop opacity requirements at 40 CFR
60.272(a)(3)/60.272a(a)(3) beyond what is currently required. The NSPS
at 40 CFR part 60, subpart AA has a 6 percent opacity limit at the melt
shop except for during periods of charging and tapping, for which 20
percent and 40 percent are allowed, respectively (see 40 CFR
60.272(a)(3)). When 40 CFR part 60, subpart AAa was promulgated in
1984, the exceptions for periods of charging and tapping were removed,
and, instead, the opacity limit for the EAF melt shop was set at 6
percent at all times (see 40 CFR 60.272a(a)(3)). In 40 CFR part 60,
subpart AA, the EPA had allowed a higher opacity limit during charging
and tapping because those periods had greater potential for uncaptured
emissions than during melting and refining. Therefore, we agree with
the commenter that the clarification in the proposal that opacity
should be tested at the site with the greatest uncaptured emissions
should not be made for 40 CFR part 60, subpart AA. However, we disagree
with the commenter that the changes to 40 CFR part 60, subpart AAa
should not be made as clarifications or corrections because the
proposed rule edits clarify that the 6 percent opacity applies at all
times in all locations of the melt shop, as explained below. In 40 CFR
part 60, subpart, AAa, it was required that sources constructed,
modified, or reconstructed after 1983 achieve a greater level of
capture performance during charging and tapping than previously
required, and the exceptions during charging and tapping that were in
40 CFR part 60, subpart AA were removed. Therefore, the EPA is
including in the final rule for 40 CFR part 60, subpart AAa the
proposed clarification to the opacity testing option in 40 CFR
60.273a(d)(2), when a facility chooses to forgo using a furnace static
pressure monitoring device on an EAF equipped with a DEC system, to
test opacity no less than once per week from the tap of one EAF heat
cycle to the tap of the following heat cycle. This clarification along
with the test method and procedure requirements in 40 CFR 60.275a(e),
make it clear that the facility is required to demonstrate compliance
with melt shop opacity at all times, including the period of the
furnace cycle that provides the greatest challenge to the capture
system, which was originally intended when creating 40 CFR part 60,
subpart AAa. In addition, the proposed clarification in 40 CFR
60.272a(a)(3) is being finalized in this rulemaking for 40 CFR part 60,
subpart AAa, that where it is possible to determine that a number of
visible emission sites relate to only 1 incident of visible emissions,
only 1 observation of shop opacity is required, at the site of highest
opacity that directly relates to the cause (or location) of visible
emissions observed during the single incident. The comments concerning
the requirement in the proposed changes to 40 CFR part 60, subpart AAb,
for shop opacity observations to be made during charging and tapping or
during the period of the heat cycle that generates the greatest
uncaptured emissions, are no longer relevant due to changes made to the
proposed 40 CFR part 60, subpart AAb for the final rule, to allow 6
percent opacity during charging and tapping and to require testing
during all phases of operation, i.e., melting and refining, charging,
and tapping, Because monitoring opacity is already required in 40 CFR
part 60, subpart AAa in the various parts of the rule discussed in the
preceding paragraphs, the clarifications of measuring melt shop opacity
do not involve the purchase of equipment not currently used at the
facility and, therefore, are included in this final rule. Compliance
with these rule clarifications of 40 CFR part 60, subpart AAa are
required 180 days from the effective date of the final rule amendments,
the same as the requirement for electronic reporting.
     Volumetric Flow and Static Pressure Response. We proposed
the requirement to continuously monitor and have operational
restrictions for either volumetric flow rate or static pressure at each
separately ducted hood for 40 CFR part 60, subpart AA, AAa, and AAb
because it provides better information about emissions capture at the
EAF and AOD and compliance assurance with melt shop opacity
requirements at 40 CFR 60.272(a)(3), 60.272a(a)(3), and 60.272b(a)(3)
than what is currently required in 40 CFR

part 60, subparts AA and AAa. In 40 CFR part 60, subpart AA, AAa, and
AAb, there are multiple options for monitoring operations at a facility
(40 CFR 60.274(b),60.274a(b), and 60.274b(b)), which may include
monitoring of volumetric flow and static pressure at each separately
ducted hood. Continuous monitoring of volumetric flow rate or static
pressure at each separately ducted hood would provide better
information about capture at each separately ducted hood and a more
direct measure of capture at each separately ducted hood. However, we
agree with the commenter that this change should not be made as a
correction because using this monitoring method/compliance option would
involve the purchase of equipment not currently available or installed
at facilities. Therefore, this requirement is not included in the final
rule for 40 CFR part 60, subparts AA, AAa, and AAb.
    Comment: A commenter asserted that the CAA limits the EPA's NSPS
revision authority to only new sources. Commenter stated there is no
denying that the proposed monitoring and associated revisions to 40 CFR
part 60, subpart AA and AAa are materially substantive and are not
error corrections, clarifications, or clerical adjustments. These
changes far exceed the EPA's legal authority to revise a NSPS
applicable to existing sources. The commenter continued, the EPA's
legal authority under the CAA is very limited as it relates to
revisions to existing NSPSs. The 40 CFR part 60, subpart AA and AAa
proposed revisions (BLDS, furnace static pressure monitoring,
volumetric flow monitoring, etc.) all constitute an ``emission
limitation'' as defined by the CAA and, therefore, constitute a
``standard of performance.'' The EPA has no authority under the CAA to
make any such revisions to a ``standard of performance'' unless those
revisions are expressly applicable to ``new sources.'' The commenter
said the proposed changes to the melt shop monitoring requirements were
arbitrary and violate the basic premise of NSPS that revisions apply
only to facilities that qualify as new, modified, or reconstructed
after proposal of the NSPS requirements.
    The commenter also said the EPA does not have the authority to add
new monitoring requirements for charging and tapping operations. The
existing shop opacity monitoring in 40 CFR part 60, subpart AAa
verifies efficiency of the DEC during normal operations. By expanding
monitoring requirements to cover tapping and charging (a time period
the furnace roof is rolled back, and the DEC control is not engaged),
the EPA was creating new monitoring requirements designed to monitor a
standard that was not included in the original rule. The proposed
monitoring during charging and tapping cannot evaluate DEC capture
efficiency, as the shop opacity observations were originally designed
to do. Hence, the addition of the new monitoring, the commenter said,
represents an unlawful revision to the existing NSPS standard.
    The commenter was concerned the EPA was adding entirely new
installation, monitoring, and maintenance requirement for charging and
tapping furnace modes, including requirements for operators to install,
calibrate, and maintain monitoring devices that continuously record the
capture system damper position(s) and either the volumetric flow rate
through each separately ducted hood or the rolling 15-minute average
static pressure at each separately ducted hood. The commenter said
these requirements are unnecessary and that they ignore the 1999
rulemaking that provided alternative monitoring methods. The commenter
also argued the EPA failed to provide a reasonable explanation for
these changes, had not explained why the additional monitoring is
needed, had not explained the EPA's change in position from prior EAF
steel NSPS rulemakings, and had neglected to account for any costs
associated with the monitoring requirements.
    EPA Response: General Monitoring Response: We proposed various
monitoring changes in 40 CFR part 60, subparts AA and AAa for purposes
of providing better information about EAF baghouse operation and
compliance assurance for the PM emission limit at 40 CFR 60.272(a)(1)/
60.272a(a)(1), and EAF capture system performance and compliance
assurance with melt shop opacity requirements at 40 CFR 60.272(a)(3)
and 60.272a(a)(3) than what is currently required.
    We learned through public comments that some of the monitoring
changes would require significant capital investment through equipment
purchases; therefore, the changes requiring purchases of equipment are
not included in the final rule for 40 CFR part 60, subparts AA and AAa.
The requirements that we are finalizing do not make the standards more
stringent; therefore, these changes do not implicate the commenter's
concern that we have improperly revised the NSPS applicable to existing
sources. For these other monitoring changes that are included in the
final rule, either as proposed or with modification of proposed
requirement, the compliance date is 180 days from the effective date of
the final rule amendments for facilities complying with 40 CFR part 60,
subparts AA and AAa, which is the same as the requirement for
electronic reporting. This time period is to allow facilities to
prepare for any changes to reporting and recordkeeping.
    The 4 proposed monitoring requirements that are not included in the
final rule are for BLDS for multi-stack baghouses for 40 CFR part 60,
subparts AA, AAa, and AAb; melt shop opacity for 40 CFR part 60,
subpart AA only; furnace static pressure monitoring and operation for
40 CFR part 60, subparts AA, AAa, and AAb; and volumetric flow and
static pressure monitoring and operation for 40 CFR part 60, subparts
AA, AAa, and AAb. The 2 proposed monitoring requirements that have been
retained in the final rule, as proposed, are melt shop inspection (for
40 CFR part 60, subparts AA, AAa, and AAb) and melt shop opacity (for
40 CFR part 60, subparts AAa and AAb). The 2 proposed monitoring
requirements that have been retained with modification are for damper
position and for fan amperage (for 40 CFR part 60, subparts AA, AAa,
and AAb), where we are finalizing the requirement for facilities to
record damper positions and fan amperage in a manner and frequency
consistent with records made during the initial or most recent
performance test demonstrating compliance with applicable PM standards.
For additional explanation and rationale behind the 7 proposed
requirements and their disposition in the final rule, refer to the
discussions in this preamble under the following section headings
(listed alphabetically): BLDS Response; Damper Position Response; Fan
Amperage Response; Furnace Static Pressure Response; Melt Shop
Inspection Response; Melt Shop Opacity Response; and Volumetric Flow
and Static Pressure Response.
    Comment: A commenter asserted that the current compliance
demonstration requirements using the fan amperage and damper position
monitoring in 40 CFR part 60, subparts AA, AAa are the best methods for
assuring compliance with the melt shop NSPS standards and, therefore,
the commenter opposes the proposed new monitoring requirements for 40
CFR part 60 subpart AAb.
    The commenter opposed the following proposed new monitoring
requirements for 40 CFR part 60 subpart AAb:
     Installation of bag leak detection monitoring systems on
all baghouses, including multi-stack baghouses;
     Monitoring and operational restriction for furnace static
pressure

monitoring based on 15-minute averages on all EAF;
     Monitoring and operational restriction for volumetric flow
rate or static pressure at each separately-ducted hood, based on 15-
minute averages on all EAF;
     Removal of the option for monitoring and operational
restriction for fan amps;
     Adding inspections and maintenance requirements for holes
or other openings in the melt shop building; and
     Mandate for shop opacity observations to be made during
charging and tapping or during the period of the heat cycle that
generates the greatest uncaptured emissions.
    The commenter considered these new monitoring requirements to be
unnecessary, expensive, and, some cases, impractical. The commenter
said the existing monitoring requirements (in 40 CFR part 60, subparts
AA and AAa) are adequate for demonstrating compliance with the
standards. The commenter stated that the existing fan amperage and
damper position monitoring have worked efficiently and effectively for
many years and the proposed new monitoring would be less effective and
would impose extreme technical and engineering complications on EAF
plants. Similarly, a commenter urged the EPA to keep the current
requirement for monitoring fan amperage in place, because they said
this parameter directly correlates to the air flow to the control
device, via the fan curve, which is unique to each site.
    A commenter stated the EPA should clarify how the proposed new
monitoring requirements improve compliance demonstration. The commenter
said it was unclear how the additional monitoring requirements in the
proposed [40 CFR part 60,subpart AAb] rule will improve data or
accuracy in demonstrating compliance with applicable requirements. The
proposed NSPS 40 CFR part 60, subpart AAb requires monitoring of
parameters that are not required to be monitored under the existing
NSPS 40 CFR part 60, subparts AA and AAa standards. The commenter
recommended the EPA explain the benefits of new monitoring techniques
and additional monitoring parameters. The monitoring requirements
should provide enough data to accurately demonstrate compliance with
applicable requirements. The commenter added that the EPA must consider
the cost to air agencies and facilities and associated benefits to
compliance before requiring additional monitoring. Additional
monitoring with no clear benefit is burdensome for both regulated
facilities and delegated authorities due to additional equipment,
maintenance, and operator costs.
    EPA Response: We considered the comments submitted by the commenter
and have modified the final rule for 40 CFR part 60, subpart AAb for
certain proposed requirements to reflect this and other comments
received, and removed other requirements entirely. We included some
monitoring requirements in the final rules, as proposed. Our response
to each issue listed by the commenter are described in this section in
the EPA responses to the comments, as follows: BLDS Response; Damper
Position Response; Fan Amperage Response; Furnace Static Pressure
Response; Melt Shop Inspection Response (as well as the EPA's response
to the proposed requirements in 40 CFR 60.274b(d) for 40 CFR part 60,
subpart AAb in regard to allowing operators discretion in an inspection
as to what issues ``materially impact'' the capture system
performance); Melt Shop Opacity Response; Volumetric Flow and Static
Pressure Response; and General Monitoring Response.
    The comment concerning a proposed requirement in 40 CFR part 60,
subpart AAb for shop opacity observations to be made during charging
and tapping or during the period of the heat cycle that generates the
greatest uncaptured emissions is no longer relevant due to changes made
to the proposed 40 CFR part 60, subpart AAb for the final rule, to
allow 6 percent opacity during charging and tapping and to require
testing during all phases of operation, i.e., melting and refining,
charging, and tapping.
    Comment: A commenter asserted that the EPA should define the term
``material impact'' (40 CFR 60.274e, 60.274a(d), and 60.274b(d)) in
terms of opacity limits and only require repairs when holes result in
noncompliance with the opacity standards.
    A commenter recommended the EPA better define a ``material impact''
on the capture system because they said the phrase was too vague. Any
airflow changes, they said, may theoretically impact capture efficiency
to some extent, but fluctuations that do not affect the compliance of
the facility with the substantive emission and opacity standards should
not be prohibited. The EPA should define material impacts in terms of
opacity limits by revising 40 CFR part 60, subparts AA, AAa, and AAb to
only require repairs to openings that lead to noncompliance with the
opacity standards.
    EPA Response: The Melt Shop Inspection Response earlier in this
section provides part of the EPA response to this comment concerning
proposed requirements for 40 CFR part 60, subpart AAb (40 CFR
60.274b(d)), which is the same as the EPA response for the proposed
clarifications in 40 CFR part 60, subparts AA and AAa (40 CFR 60.274(e)
and 60.274a(d)) and explains why we disagree with the commenter and are
including the requirement to inspect for holes or other openings in the
melt shop in the final rules to ensure compliance with the opacity
standards in 40 CFR part 60, subparts AA, AAa, and AAb.
    In addition, for 40 CFR part 60, subpart AAb, we proposed the
requirement for monthly inspections to include the language to address
issues that are ``determined by the operator to materially impact the
efficacy of the capture system'' in 40 CFR 60.274b(d). This allows for
a determination by the operator as to whether an identified issue is to
be considered a true deficiency that is expected to impact capture
system performance, as opposed to the language in 40 CFR part 60,
subpart AAa that requires maintenance for ``any deficiency.''
Therefore, we agree with this aspect of the comment and are including
the proposed rule language for monthly inspections that allow for
operator discretion as to what issues ``materially impact'' the capture
system performance in the final rule for 40 CFR part 60, subpart AAb
(40 CFR 60.274b(d)).
    Comment: A commenter asserted that the EPA should clarify the
calculation for determining compliance with the opacity limits when
using EPA Method 9 for 40 CFR part 60, subpart AAb. The commenter asked
the EPA to clarify in the rule how facilities should determine
compliance with the opacity limits. The commenter noted that compliance
with the shop opacity limits will be determined based on the arithmetic
average of 24 consecutive 15-second opacity observations over a 6-
minute period. The commenter said that it is their understanding that
the proposed zero opacity standard does not require all 24 15-second
EPA Method 9 observation periods to be zero percent and that some of
the 24 readings may exceed 0 percent provided the arithmetic average
rounds down to 0. Similarly, in calculating compliance with the
existing 6 percent shop opacity standard, some readings can exceed 6
percent provided the arithmetic average rounded down is below 6
percent. The commenter asked the EPA to confirm their interpretation of
the rule is correct.

    The commenter noted that this approach is consistent with prior
NSPS rulemakings, including 40 CFR part 60, subpart KK (Lead-Acid
Battery Manufacturing) and 40 CFR part 60, subpart NN (Phosphate Rock
Plants). However, the commenter said the EPA specified in 40 CFR part
60, subparts KK and NN that compliance with the opacity standard is
determined by taking the average opacity over a 6-minute period,
according to EPA Method 9, and rounding the average to the nearest
whole percentage (45 FR 2790 and 2794; January 14, 1980 and 47 FR
16564, 16566, 16582, and 16586; April 16, 1982). The commenter
recommended the EPA add the same explanation provided in these earlier
NSPS in the final shop opacity limit.
    EPA Response: The method for calculating opacity has not changed
substantially for 40 CFR part 60, subpart AAb; the final rule
incorporates the current EPA Method 9 procedures for melting and
refining, and for tapping (see section IV.B.2 in this preamble for
changes to opacity measurement procedures with EPA Method 9 during
charging). When determining the final value for opacity in 40 CFR part
60, subpart AAb, facilities should round to the nearest whole number (0
percent). Therefore, an average opacity level calculated to be 0.49
percent would round (down) to 0 percent.
3. What is the rationale for the final requirements for testing and
monitoring?
    We are finalizing the proposed requirement in 40 CFR part 60,
subparts AA, AAa, and AAb that the melt shop be inspected for holes or
other openings that would allow PM to escape because it clarifies the
building inspection requirement already in the current NSPS. We are
also incorporating into the final rules for 40 CFR part 60, subparts
AA, AAa, and AAb the allowance of up to 24 hours to find and fix
baghouse leaks following a BLDS alarm event because it is commensurate
with many other EPA rules and no evidence exists for the specific need
for limiting the tie period to 3 hours for EAF. The reasons that more
than 3 hours and up to 24 hours is needed to respond to BLDS alarms
provided by the commenter are valid. We are finalizing that sources
complying with 40 CFR part 60, subpart AAb will be required to perform
compliance testing every 5 years after the initial testing performed
upon startup, as required under 40 CFR part 60.8. This requirement is
already required in many of the permits for existing EAF in the EAF
dataset and in the industry, and is a standard requirement for testing
for other sources of PM emissions for many other industrial sectors.
    We learned through public comments that some of the proposed
monitoring changes, BLDS monitoring, furnace static pressure monitoring
and operation, and volumetric flow and static pressure monitoring and
operation, would require significant capital investment through
equipment purchases. Therefore, these changes requiring purchases of
equipment are not being finalized for 40 CFR part 60, subparts AA, AAa,
and AAb.
    We are finalizing 2 proposed monitoring requirements for 40 CFR
part 60, subparts AA, AAa, and AAb, which are the requirements for melt
shop inspection and stipulation that the melt shop opacity limits apply
at all times during the designated periods of applicability under the
rules. We are also finalizing the proposed damper position and fan
amperage monitoring requirements with modifications. Other
miscellaneous monitoring requirements also are being finalized with
modifications resulting from comments on the proposed requirements, as
described in in this section.
    All testing and monitoring requirements proposed and finalized in
this action were evaluated to ensure compliance with the NSPS emission
standards under conditions of proper operation and maintenance.
However, because we learned through comments that some of the proposed
changes to monitoring in the existing NSPS rules would incur unintended
costs, these requirements were either not finalized in their entirety
or were finalized with modifications.

F. Electronic Reporting

    The EPA is finalizing the proposed requirement that owners and
operators of EAF and AOD subject to the current and new NSPS at 40 CFR
part 60, subparts AA, AAa, and AAb submit electronic copies of required
performance test reports and any semiannual excess emissions and
continuous monitoring system performance and summary reports, through
the EPA's CDX using the CEDRI. A description of the electronic data
submission process is provided in the memorandum Electronic Reporting
Requirements for New Source Performance Standards (NSPS) and National
Emission Standards for Hazardous Air Pollutants (NESHAP) Rules,\18\
available in the docket for this action, and hereafter referred to as
the ``Electronic Reporting Memorandum.'' The finalized rule requires
that performance test/demonstration of compliance results collected
using test methods that are supported by the EPA's ERT as listed on the
ERT website \19\ at the time of the test be submitted in the format
generated through the use of the ERT or an electronic file consistent
with the xml schema on the ERT website, and other performance test/
demonstration of compliance results be submitted in PDF using the
attachment module of the ERT.
---------------------------------------------------------------------------

    \18\ Electronic Reporting Requirements for New Source
Performance Standards (NSPS) and National Emission Standards for
Hazardous Air Pollutants (NESHAP) Rules. Memorandum, Measurement
Policy Group, U.S. Environmental Protection Agency, Research
Triangle Park, NC. August 19, 2020.
    \19\ https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert.
---------------------------------------------------------------------------

    For semiannual reports, the finalized rule requires that owners and
operators use the appropriate spreadsheet template to submit
information to CEDRI. The final versions of the templates for these
reports are included in the docket for this action.\20\
---------------------------------------------------------------------------

    \20\ See 40 CFR part 60, subpart AA, AAa, and AAb, Standards of
Performance for Steel Plants: Electric Arc Furnaces and Argon-Oxygen
Decarburization Vessels, 40 CFR part 60.276(g) Semiannual Compliance
Report Spreadsheet Template, available at Docket ID No. EPA-HQ-OAR-
2002-0049-0064.
---------------------------------------------------------------------------

    Additionally, the EPA has identified 2 broad circumstances in which
electronic reporting extensions may be provided. These circumstances
are: (1) Outages of the EPA's CDX or CEDRI which preclude an owner and
operator from accessing the system and submitting required reports; and
(2) force majeure events, which are defined as events that will be or
have been caused by circumstances beyond the control of the affected
facility, its contractors, or any entity controlled by the affected
facility that prevent an owner and operator from complying with the
requirement to submit a report electronically. Examples of force
majeure events are acts of nature, acts of war or terrorism, equipment
failure, or safety hazards beyond the control of the facility. The EPA
is providing these potential extensions to protect owners and operators
from noncompliance in cases where they cannot successfully submit a
report by the reporting deadline for reasons outside of their control.
In both circumstances, the decision to accept the claim of needing
additional time to report is within the discretion of the
Administrator, and reporting should occur as soon as possible.
    The electronic submittal of the reports addressed in this final
rulemaking increase the usefulness of the data

contained in those reports and is keeping with current trends in data
availability and transparency. Electronic submittal would further
assist in the protection of public health and the environment by
improving compliance, facilitating the ability of regulated facilities
to demonstrate compliance with requirements, and by facilitating the
ability of delegated state, local, Tribal, and territorial air agencies
and the EPA to assess and determine compliance. Ultimately, electronic
reporting would reduce the burden on regulated facilities, delegated
air agencies, and the EPA by making the data easy to record and read.
Electronic reporting also eliminates paper waste and redundancies and
minimizes data reporting errors. The resulting electronic data are more
quickly and accurately accessible to the affected facilities, air
agencies, the EPA, and the public. Moreover, electronic reporting is
consistent with the EPA's plan \21\ to implement Executive Order 13563
and is in keeping with the EPA's agency-wide policy \22\ developed in
response to the White House's Digital Government Strategy.\23\ For more
information on the benefits of electronic reporting, see the
``Electronic Reporting Memorandum'' discussed earlier in this section.
---------------------------------------------------------------------------

    \21\ EPA's Final Plan for Periodic Retrospective Reviews (August
2011). Available at: https://www.regulations.gov/document?D=EPA-HQ-OA-2011-0156-0154.
    \22\ E-Reporting Policy Statement for EPA Regulations (September
2013). Available at: https://www.epa.gov/sites/default/files/2016-03/documents/epa-ereporting-policy-statement-2013-09-30.pdf.
    \23\ Digital Government: Building a 21st Century Platform to
Better Serve the American People (May 2012). Available at: https://obamawhitehouse.archives.gov/sites/default/files/omb/egov/digital-government/digital-government.html.
---------------------------------------------------------------------------

    No comments were received on electronic reporting. Therefore, we
are finalizing the requirements for electronic reporting as proposed.

G. Effective Date and Compliance Dates

    Pursuant to CAA section 111(b)(1)(B), affected sources that
commence construction, reconstruction, or modification after May 16,
2022, must comply with all requirements of 40 CFR part 60, subpart AAb,
no later than August 25, 2023 or upon startup, whichever is later.
    The date for complying with the ERT submission requirements is
February 21, 2024. The date for complying with the changes in the
current rules, 40 CFR part 60, subparts AA and AAa is February 21, 2024
publication of the final rule.

V. Summary of Cost, Environmental, and Economic Impacts

A. What are the air quality impacts?

    For 40 CFR part 60, subpart AAb, reductions in PM and
PM2.5 potentially emitted from new, modified, and
reconstructed EAF compared to these emissions allowed under the current
NSPS subpart AAa with 6 percent melt shop opacity will have a
beneficial air impact.
    Based on the actual emissions emitted by 31 facilities in the EAF
dataset, where the actual average opacity was 0.14 percent, the
emissions impact for PM from 9 new, modified, or reconstructed EAF
facilities projected in the next 10 years (estimated to reflect 3
small, 4 medium, and 2 large) is estimated to be an emissions reduction
of 134 tons PM that would otherwise be emitted in 2032. Using an
estimate of 0.218 \24\ for the ratio of PM2.5 to PM the
emissions impact for PM2.5 from nine new facilities
projected in the next 10 years, as above, there would be an emissions
reduction of 28 tons of PM2.5 in 2032. Details of these
emissions estimates can be found in the ``Emissions Memorandum''
discussed in section IV.A.2.
---------------------------------------------------------------------------

    \24\ The PM2.5 to PM ratio is an average of similar
uncontrolled sources, as cited in Evaluation of PM2.5
Emissions and Controls at Two Michigan Steel Mills and a Coke Oven
Battery. Final Report. Work Assignment 4-12 under EPA Contract No.
68-D-01-073 by RTI International, Research Triangle Park, NC. U.S.
Environmental Protection Agency, Research Triangle Park, NC.
February 2006.
---------------------------------------------------------------------------

    No actual PM emission reductions are estimated for the new PM limit
for facility-wide total baghouse emissions in lb/ton. The EPA did not
estimate PM emission reductions from new, modified, and reconstructed
sources under the facility-wide total baghouse limit because based the
2010 EAF dataset, all facilities in the dataset are already achieving
an emission level comparable to the limit being finalized in this
action.

B. What are the secondary impacts?

    A secondary impact as a result of this rule is that solid wastes
may increase slightly, with an estimated 15 tons per facility per year
based on 2010 EAF performance, with the potential additional waste from
PM collected to meet the 0 percent melting and refining opacity limit
under NSPS subpart AAb. The small increase in solid wastes would be the
same for both the carbon and specialty steel shops. However, most PM
collected from EAF is recycled to reclaim zinc, which also defrays some
of the disposal costs.25 26
---------------------------------------------------------------------------

    \25\ Proven Waelz Kiln Technology. Accessed 2/18/22. http://www.globalsteeldust.com/waelz_kiln_technology.
    \26\ R[uuml]tten, J. Application of the Waelz Technology on
Resource Recycling of Steel Mill Dust. D[uuml]sseldorf: GmbH. D-
40225, 2006.
---------------------------------------------------------------------------

    Additionally, a relatively small increase in energy may result from
the use of electricity to power fans that draw EAF and AOD exhaust air
into the canopy hood that captures the PM and sends PM-laden air to the
baghouse, at 66, 940, 4,700 MW-hr per year for small, medium, and large
facilities, respectively. However, if the A/C ratio of the fabric
filters is lowered to meet the facility baghouse standard due to an
increase in number of bags, some decrease in energy use may occur.
    Finally, there will be no water or noise impacts with the
promulgated NSPS subpart AAb.

C. What are the cost impacts?

    Costs were estimated for regular testing every 5 years for 9 new
facilities projected in the 10 years after May 16, 2022. The estimated
annual testing costs for each facility are $10,625 per year ($2022) for
conducting EPA Method 5 for PM emissions at each baghouse's exhaust
over a 5-year period, using an estimate of 1.64 baghouses per facility
based on the EAF data. While new, modified, or reconstructed sources
that start up after May 16, 2022, are subject to testing every 5 years
under the finalized NSPS subpart AAb, EPA Method 5 testing is required
upon initial startup under 40 CFR 60.8. Therefore, in the first 5 years
after startup, there will be no testing costs as a result of the
finalized rule. Then, in the sixth through the tenth year after initial
startup after May16, 2022, the estimated new, modified, or
reconstructed sources will incur costs of approximately $9,562 per year
($2022) per facility for testing, based on an estimate of 0.9 new,
modified, or reconstructed facilities per year (0.9 x $10,625). Due to
the estimated staggered startup of these new, modified, or
reconstructed facilities, with 0.9 new, modified, or reconstructed
facilities starting each year after the proposal (May 16, 2022), the
total costs for testing for all new, modified, or reconstructed
facilities under this rule after the initial testing required under 40
CFR part 60.8 will range from approximately $523,000 ($2022) in the
sixth year after May 16, 2022 (corresponding to 5.4 new facilities), to
a total of approximately $900,000 in the tenth year after May 16, 2022
(reflecting costs for 9 facilities, with testing costs of approximately

$100,000 per facility per year), where the testing costs that would
occur in years 6 through 10 are for the new, modified, or reconstructed
facilities that start up in years 1 through 5 after May 16, 2022.
    Based on information from 2010 through 2017 obtained by the EPA for
31 EAF facilities, the EPA found the average opacity to be 0.14
percent, with about half of the units achieving 0 percent opacity in
the tests. Because opacity in the baseline is already low, the EPA
expects any new, modified, or reconstructed facility would be able to
meet the promulgated opacity and PM limits without any additional
control devices beyond those already required by the NSR program,
applicable state requirements or by minor process changes to improve
capture of exhaust flows or other process parameters, if needed. While
the actual cost impacts of the promulgated 0 percent opacity for
melting and refining and 6 percent opacity for charging and tapping
would likely be substantially lower, the EPA developed an upper bound
estimate of potential compliance costs based upon the assumption that
affected units would install a partial roof canopy above the crane
rails to ensure 0 percent opacity during melting and refining and 6
percent opacity during charging and tapping compared to a hypothetical
baseline model facility meeting 6 percent opacity at all times. These
costs to achieve the opacity requirements are estimated to be $86,000,
$1,140,000, $5,700,000 ($2022) per year per facility for small, medium,
and large model facilities, respectively.
    Total annual costs for NSPS subpart AAb, based on nine new,
modified, or reconstructed facilities in the first 10 years after May
16, 2022, are $560,000 per year ($2022) for 3 small facilities, $4.9M
per year for 4 medium facilities, and $11.5M per year for 2 large
facilities, for a total of $17M per year ($2022) for 9 new facilities
in the tenth year after May 16, 2022, using the same staggered startup
rate described for testing costs. Details of the cost estimates for the
final rule can be found in the ``Cost Memorandum'' discussed in section
IV.A.2 (with proposal costs updated to 2022 \27\) which can be found in
the docket for this rule.
---------------------------------------------------------------------------

    \27\ In the time since the proposal costs were assessed in 2020,
inflation has increased with a subsequent increase in the gross
national product (GNP), which is the basis for the U.S. dollars used
in the costs estimates. In addition, interest rates, which affect
capital costs, increased from 3.5 percent to 7.5 percent from
proposal cost preparation (in 2021) to final rule cost preparation
(in 2022).
---------------------------------------------------------------------------

    For the promulgated mass-based PM standard in lb/ton for facility-
wide total baghouse PM emissions, we estimated the capital and annual
costs between a baseline scenario based on the current NSPS individual
baghouse concentration limit (in gr/dscf) in 40 CFR part 60, subparts
AA and AAa and a scenario based on a lower total facility-wide baghouse
PM emissions in a mass-based limit (in lb/ton), which is the format for
the standard of performance we are promulgating. Because data from the
31 existing EAF facilities in the 2010 dataset used by the EPA to
develop the facility-wide PM limit show these facilities could already
meet the 0.16 lb/ton total facility baghouse PM limit, we expect the
promulgated mass-based standard applied to future new, modified, and
reconstructed EAF facilities would be feasible and pose minimal cost
impacts, if any.
    Additional cost analysis, including calculation of costs using the
upper bound cost estimates for the installation of partial roof
canopies, can be found in the Economic Impact Analysis (EIA) associated
with this final rule, which is available in the docket for this rule.
The EIA additionally presents costs in terms of the present value and
equivalent annual value of projected compliance costs over the 2023 to
2032 period discounted at 3 and 7 percent.

D. What are the economic impacts?

    Economic impact analyses focus on changes in market prices and
output levels. If changes in market prices and output levels in the
primary markets are significant enough, impacts on other markets may
also be examined. Both the magnitude of costs associated with the
promulgated requirements and the distribution of these costs among
affected facilities can have a role in determining how the market will
change in response to a regulatory requirement. As discussed in section
IV.B. of this preamble, the cost analysis incorporates the assumption
that units affected by the new NSPS subpart AAb would install a partial
roof canopy above the crane rails to ensure 0 percent melt shop opacity
compared to a hypothetical baseline model facility meeting 6 percent
opacity. The costs should be viewed as upper bound estimates on the
potential compliance costs as the EPA expects any new, modified or
reconstructed facility would be able to meet the promulgated opacity
and PM limits without any additional control devices beyond those
already required by the NSR program, applicable state requirements, or
by minor process changes to improve capture of exhaust flows or other
process parameters, if needed. As discussed in the EIA, even under the
upper bound cost assumptions described, the EPA expects the potential
economic impacts of this final rule will be small.
    As required by the Regulatory Flexibility Act (RFA), we performed
an analysis to determine if any small entities might be
disproportionately impacted by the promulgated requirements. The EPA
does not know what firms will construct new facilities in the future
and, as a result, cannot perform a cost-to-sales analysis with the same
confidence as we do with firms owning existing facilities. However,
based on an assessment of the new units built during the 2011 to 2020
period and the units that have been announced, which are all owned by
firms that are not considered to be small businesses, the EPA does not
believe it is likely that any future facilities will be built by a
small business. See the EIA in the docket for this action for
additional information on the analysis presented in this section.

E. What are the benefits?

    The new requirements being finalized in 40 CFR subpart AAb are
expected to reduce PM emissions, including PM2.5. In
addition, the revisions to 40 CFR part 60, subparts AA and AAa will
clarify the rules, enhance compliance and enforcement, and is expected
to reduce PM emissions, including PM2.5. As explained in
section IV.A of this preamble, the requirements are projected to reduce
28 tons of PM2.5 in 2032. These emissions reductions are
expected to produce health benefits in the affected locations. The
Integrated Science Assessment for Particulate Matter (ISA) \28\
contains synthesized toxicological, clinical, and epidemiological
evidence that the EPA uses to determine whether each pollutant is
causally related to an array of adverse human health outcomes
associated with either acute (i.e., hours or days-long) or chronic
(i.e., years-long) exposure. For each outcome, the ISA includes the EPA
conclusions as to whether this relationship is causal, likely to be
causal, suggestive of a causal relationship, inadequate to infer a
causal relationship, or not likely to be a causal relationship.
---------------------------------------------------------------------------

    \28\ Integrated Science Assessment for Particulate Matter (Final
Report, 2019). EPA/600/R19/188. U.S. Environmental Protection
Agency, Washington, DC. 2019.
---------------------------------------------------------------------------

    In the ISA, it was found that acute exposure to PM2.5
was causally related to cardiovascular effects and mortality (i.e.,
premature death), and respiratory

effects as likely-to-be-causally related. Further, the EPA identified
cardiovascular effects and total mortality as causally related to long-
term exposure to PM2.5 and respiratory effects as likely-to-
be-causal; the evidence was suggestive of a causal relationship for
reproductive and developmental effects as well as cancer, mutagenicity,
and genotoxicity.
    The benefits per ton (BPT) of the PM2.5 emissions
reductions cited earlier in this preamble for years 2025 and 2030 and
at 3 percent and 7 percent discount rates are presented in Table 7
below in 2022 dollars. The BPT of the PM2.5 emissions
reductions for year 2025, at a 3 percent discount rate translates to a
low projection of $417,000 per ton emission reduction, to a high
projection of $891,000 per ton emission reduction (in 2022 dollars).
Information regarding the process by which these BPTs were calculated
is available in the technical support document Estimating the Benefit
per Ton of Reducing Directly-Emitted PM2.5, PM2.5 Precursors, and Ozone
Precursors from 21 Sectors.

                                   Table 7--Benefits per Ton of PM2.5 Reduced
----------------------------------------------------------------------------------------------------------------
                                                               $/ton PM2.5 emission reductions $2022
                                                 ---------------------------------------------------------------
                      Year                            3 Percent discount rate         7 Percent discount rate
                                                 ---------------------------------------------------------------
                                                        Low            High             Low            High
----------------------------------------------------------------------------------------------------------------
2025............................................        $417,000        $891,000        $375,000        $803,000
2030............................................         451,000         933,000         405,000         839,000
----------------------------------------------------------------------------------------------------------------
Note: The range reported here reflects the use of risk estimates from two alternative long-term exposure PM-
  mortality studies.\29\

F. What analysis of environmental justice did we conduct?

    Executive Order 12898 directs the EPA to identify the populations
of concern that are most likely to experience unequal burdens from
environmental harms, which are specifically minority populations
(people of color), low-income populations, and Indigenous peoples (59
FR 7629; February 16, 1994). Additionally, Executive Order 13985 is
intended to advance racial equity and support underserved communities
through Federal government actions (86 FR 7009; January 20, 2021). 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.'' \30\ 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.'' In recognizing that people of color and low-income
populations often bear an unequal burden of environmental harms and
risks, the EPA continues to consider ways of protecting them from
adverse public health and environmental effects of air pollution. For
purposes of analyzing regulatory impacts, the EPA relies upon its June
2016 ``Technical Guidance for Assessing Environmental Justice in
Regulatory Analysis,'' \31\ which provides recommendations that
encourage analysts to conduct the highest quality analysis feasible,
recognizing that data limitations, time, resource constraints, and
analytical challenges will vary by media and circumstance. The
Technical Guidance states that a regulatory action may involve
potential EJ concerns if it could: (1) Create new disproportionate
impacts on minority populations, low-income populations, and/or
Indigenous peoples; (2) exacerbate existing disproportionate impacts on
minority populations, low-income populations, and/or Indigenous
peoples; or (3) present opportunities to address existing
disproportionate impacts on minority populations, low-income
populations, and/or Indigenous peoples through this action under
development.
---------------------------------------------------------------------------

    \29\ Estimating the Benefit per Ton of Reducing Directly-emitted
PM2.5, PM2.5 Precursors and Ozone Precursors
from 21 Sectors. U.S. Environmental Protection Agency, Office of Air
and Radiation, Office of Air Quality Planning and Standards,
Research Triangle Park, NC 27711. 2022. Available at: https://www.epa.gov/system/files/documents/2021-10/source-apportionment-tsd-oct-2021_0.pdf.
    \30\ See https://www.epa.gov/environmentaljustice.
    \31\ See https://www.epa.gov/environmentaljustice/technical-guidance-assessing-environmental-justice-regulatory-analysis.
---------------------------------------------------------------------------

    The Agency has conducted an analysis of the demographics of the
populations living near existing facilities in the EAF population in
the U.S. Because this action finalizes standards of performance for
new, modified, and reconstructed EAF sources that commence construction
after May 16, 2022, the locations of the construction of new EAF
facilities are not known. In addition, it is not known which of the
existing facilities will be modified or reconstructed in the future.
Therefore, the demographic analysis was conducted for the 88 existing
EAF facilities as a characterization of the demographics in areas where
these facilities are now located.
    The full results of the demographic analysis can be found in
section E, ``What are the environmental justice impacts?,'' of the
preamble to the proposed rule (87 FR 29724). The analysis included an
assessment of individual demographic groups of the populations living
within 5 km and within 50 km of the existing facilities. We then
compared the data from the analysis to the national average for each of
the demographic groups. The results show that for populations within 5
km of the 87 existing EAF facilities (we identified one additional
existing facility since the proposed rule was published for a total of
88 facilities, but the overall results did not change). The percent of
the population that is African American is above the national average
(17 percent versus 12 percent). The percent of people living below the
poverty level is also above the national average (17 percent versus 13
percent). The percent of the population that is Native American,
Hispanic or Latino, or Other/Multiracial are below the national
averages. The percent of the population over 25 without a high school
diploma and the percent of the population in linguistic isolation are
similar to the national averages. The results of the analysis of
populations within 50 km of the 88 EAF facilities is similar to the 5
km analysis.
    The methodology and the results of the demographic analysis for the
final rule are presented in a technical report, Analysis of Demographic
Factors for Populations Living Near Electric Arc Furnace Facilities,
available in the docket for this action (Docket ID No. EPA-HQ-OAR-2002-
0049).

    The EPA expects that the Standards of Performance for Steel Plants:
Electric Arc Furnaces and Argon-Oxygen Decarburization Vessels
Constructed after May 16, 2022, will ensure compliance via frequent
testing and reduce emissions via a lower opacity limit for melt shops
and with the standards at all times (including periods of SSM). The
rule will also increase data transparency through electronic reporting.
Therefore, effects of emissions on populations in proximity to any
future affected sources, including in communities potentially
overburdened by pollution, which are often people of color, and low-
income and Indigenous communities will be reduced due to compliance
with the standards of performance being finalized in this action.

VI. Statutory and Executive Order Reviews

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

A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 14094: Modernizing Regulatory Review

    This action is not a significant regulatory action as defined in
Executive Order 12866, as amended by Executive Order 14094, and was,
therefore, not subject to a requirement for Executive Order 12866
review.

B. Paperwork Reduction Act (PRA)

    The information collection activities in this final rule have been
submitted for approval to OMB under the PRA. The information collection
request (ICR) document that the EPA prepared has been assigned the EPA
ICR number 1060.21. You can find a copy of the ICR in the docket for
this rule, and it is briefly summarized here. The information
collection requirements are not enforceable until OMB approves them.
    These amendments to 40 CFR part 60, subparts AA and AAa to require
electronic reporting, and implement editorial and clarifying changes to
rule language are estimated to reduce time spent and paperwork for
rule. We are promulgating a new subpart for new, modified, or
reconstructed facilities that start up after May 16, 2022, under 40 CFR
part 60, subpart AAb with similar reporting, recordkeeping, and
compliance requirements as 40 CFR part 60, subparts AA and AAa.
    Respondents/affected entities: EAF and AOD facilities.
    Respondent's obligation to respond: Mandatory (40 CFR part 60,
subparts AA; AAa; and AAb).
    Estimated number of respondents: 90, includes 88 estimated current
facilities subject to 40 CFR part 60, subparts AA and AAa, and 3 new
facilities that would be subject to 40 CFR part 60, subpart AAb in the
3 years after proposal (May 16, 2022).
    Frequency of Response: One time.
    Total estimated burden: The annual recordkeeping and reporting
burden for facilities to comply with all the requirements in the NSPS
is estimated to be 57,100 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 of the requirements in the NSPS
is estimated to be $7,400,000 (per year), of which $65,686 (per year)
is for this final rule ($60,000 for EPA Method 5 compliance and $696
for electronic reporting), and $7,130,000 for other costs related to
continued compliance with the NSPS, including $198,000 for paperwork
associated with operation and maintenance requirements. The total rule
costs reflect an increase/decrease cost of $450,000 (per year) from the
previous ICR that reflects savings due to electronic reporting and an
increase to the labor rates.
    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 the three identified small
entities among the approximately 90 EAF facilities (36 companies),
because most facilities are likely to be performing regular compliance
tests as part of their permit renewal process. Additionally, no
facilities are expected to be built by small entities over the next 10
years based on past industry growth and small business starts. The 3
current facilities owned by small businesses were started in 1912,
1968, and 1994, respectively. Further discussion is included in the EIA
for this final rule.

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. While this action
creates an enforceable duty on the private sector, the cost does not
exceed $100 million or more.

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. This rule will implement improvements in air
quality due to new EAF in all locations of new EAF facilities,
including any new EAF which are in proximity to Tribal grounds. It
would not have substantial direct effects on Tribal governments, 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. No Tribal governments own facilities that
are the subject of this rulemaking. Thus, Executive Order 13175 does
not apply to this action.
    Consistent with the EPA Policy on Consultation and Coordination
with Indian Tribes, the EPA consulted with Tribal officials during the
development of this action. A copy of the memorandum dated May 17,
2022, sent to Tribal leaders concerning the EAF NSPS is provided in the
docket to this rule.

G. 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 economically

significant as defined in Executive Order 12866, and because the EPA
does not believe the environmental health or safety risks addressed by
this action present a disproportionate risk to children. The EPA does
not believe there are disproportionate risks to children because the
new subpart AAb lowers emissions from the melt shop during melting and
refining, which will benefit children's health; and other changes made
to all subparts, AA, AAa, and AAb, increase compliance with emission
limits, which also benefits children's health. However, EPA's Policy on
Children's Health applies to this action. Information on how the Policy
was applied is available under ``Children's Environmental Health'' in
the Supplementary Information section of this preamble.

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

    This action is not subject to Executive Order 13211, because it is
not a significant regulatory action under Executive Order 12866.

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

    This action involves technical standards. Therefore, the EPA
conducted searches for the EAF NSPS through the Enhanced National
Standards Systems Network Database managed by the American National
Standards Institute (ANSI). We also contacted voluntary consensus
standards (VCS) organizations and accessed and searched their
databases. We conducted searches for EPA Methods 1, 2, 3, 3A, 3B, 4, 5,
5D, and 22 of 40 CFR part 60, appendix A. During the EPA's VCS search,
if the title or abstract (if provided) of the VCS described technical
sampling and analytical procedures that are similar to the EPA's
reference method, the EPA 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 reference methods. The EPA may
reconsider determinations of impracticality when additional information
is available for a particular VCS. No applicable VCS were identified
for EPA Methods 5D and 22.
    The EPA is incorporating by reference the VCS ANSI/ASME PTC 19.10-
1981, ``Flue and Exhaust Gas Analyses,'' to provide that the manual
procedures (but not instrumental procedures) of VCS ANSI/ASME PTC
19.10-1981--Part 10 may be used as an alternative to EPA Method 3B. The
manual procedures (but not instrumental procedures) of VCS ANSI/ASME
PTC 19.10-1981--Part 10 may be used as an alternative to EPA Method 3B
for measuring the oxygen or carbon dioxide content of the exhaust gas.
This standard is acceptable as an alternative to EPA Method 3B and is
available from ASME at www.asme.org; by mail at Three Park Avenue, New
York, NY 10016-5990; or by telephone at<PHONE_NUMBER>. This method
determines quantitatively the gaseous constituents of exhausts
resulting from stationary combustion sources. The gases covered in
ANSI/ASME PTC 19.10-1981 are oxygen, carbon dioxide, carbon monoxide,
nitrogen, sulfur dioxide, sulfur trioxide, nitric oxide, nitrogen
dioxide, hydrogen sulfide, and hydrocarbons. However, the use in this
rule is only applicable to oxygen and carbon dioxide.
    In the final rule, the EPA is incorporating by reference the VCS
ASTM D7520-16, Standard Test Method for Determining the Opacity of a
Plume in the Outdoor Ambient Atmosphere, which is an instrumental
method to determine plume opacity in the outdoor ambient environment as
an alternative to visual measurements made by certified smoke readers
in accordance with EPA Method 9. The concept of ASTM D7520-16, also
known as the Digital Camera Opacity Technique or DCOT, is a test
protocol to determine the opacity of visible emissions using a digital
camera. It was based on previous method development using digital still
cameras and field testing of those methods. The purpose of ASTM D7520-
16 is to set a minimum level of performance for products that use DCOT
to determine plume opacity in ambient environments. The DCOT method is
an acceptable alternative to EPA Method 9 with the following caveats:
     During the DCOT certification procedure outlined in
Section 9.2 of ASTM D7520-16, the facility or the DCOT vendor must
present the plumes in front of various backgrounds of color and
contrast representing conditions anticipated during field use such as
blue sky, trees, and mixed backgrounds (clouds or a sparse tree stand).
     The facility must also have standard operating procedures
in place including daily or other frequency quality checks to ensure
the equipment is within manufacturing specifications as outlined in
Section 8.1 of ASTM D7520-16.
     The facility must follow the recordkeeping procedures
outlined in 40 CFR 63.10(b)(1) for the DCOT certification, compliance
report, data sheets, and all raw unaltered JPEGs used for opacity and
certification determination.
     The facility or the DCOT vendor must have a minimum of 4
independent technology users apply the software to determine the
visible opacity of the 300 certification plumes. For each set of 25
plumes, the user may not exceed 15 percent opacity of any one anyone
reading, and the average error must not exceed 7.5 percent opacity.
     This approval does not provide or imply a certification or
validation of any vendor's hardware or software. The onus to maintain
and verify the certification or training of the DCOT camera, software,
and operator in accordance with ASTM D7520-16 is on the facility, DCOT
operator, and DCOT vendor. This method describes procedures to
determine the opacity of a plume, using digital imagery and associated
hardware and software, where opacity is caused by PM emitted from a
stationary point source in the outdoor ambient environment. The opacity
of emissions is determined by the application of a DCOT that consists
of a digital still camera, analysis software, and the output function's
content to obtain and interpret digital images to determine and report
plume opacity. The ASTM D7520-16 document is available from ASTM at
www.astm.org or 1100 Barr Harbor Drive, West Conshohocken, PA 19428-
2959, telephone number:<PHONE_NUMBER>, fax number:<PHONE_NUMBER> at
[email protected].
    The EPA is finalizing the use of the guidance document, Fabric
Filter Bag Leak Detection Guidance, EPA-454/R-98-015, Office of Air
Quality Planning and Standards (OAQPS), U.S. Environmental Protection
Agency, Research Triangle Park, North Carolina, September 1997. This
document provides guidance on the use of triboelectric monitors as
fabric filter bag leak detectors. The document includes fabric filter
and monitoring system descriptions; guidance on monitor selection,
installation, setup, adjustment, and operation; and quality assurance
procedures. The document is available at https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=2000D5T6.PDF.
    Additional information for the VCS search and determinations can be
found in the three memoranda titled Voluntary Consensus Standard
Results for Standards of Performance for Steel Plants: Electric Arc
Furnaces Constructed After October 21, 1974, and

On or Before August 17, 1983; Voluntary Consensus Standard Results for
Standards of Performance for Steel Plants: Electric Arc Furnaces and
Argon-Oxygen Decarburization Vessels Constructed After August 17, 1983,
and On or Before May 16, 2022; and Voluntary Consensus Standard Results
for Standards of Performance for Steel Plants: Electric Arc Furnaces
and Argon-Oxygen Decarburization Vessels Constructed After May 16,
2022, available in the docket for this final rule.

J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898 (59 FR 7629; February 16, 1994) directs
Federal agencies, to the greatest extent practicable and permitted by
law, to make environmental justice part of their mission by identifying
and addressing, as appropriate, disproportionately high and adverse
human health or environmental effects of their programs, policies, and
activities on minority populations (people of color and/or Indigenous
peoples) and low-income populations.
    The EPA believes that the human health and environmental conditions
that exist prior to this action do not result in disproportionate and
adverse effects on people of color, low-income populations, and/or
indigenous peoples if a modified or reconstructed EAF facility becomes
subject to the final rule for 40 CFR part 60, subpart AAb, considering
the demographics analysis for the existing EAF facilities described in
section V.F of this preamble. However, it is unknown where new EAF
facilities will be located so it is not possible to predict the impacts
of these facilities on people of color, low-income populations, and/or
indigenous peoples.
    The EPA believes that this action is not likely to result in new
disproportionate and adverse effects on people of color, low-income
populations and/or indigenous peoples. The impacts of these final rules
are beneficial to all demographic groups, and include requirements to
clarify current rules in 40 CFR part 60, subparts AA, AAa and, for new
sources built after publication of this final rule (in 40 CFR part 60,
subpart AAb), to ensure compliance via frequent testing, to meet a
lower opacity limit for melt shops during melting and refining, to meet
a baghouse emissions limit as a facility-wide total in lb/ton, and to
meet all the promulgated standards at all times, including periods of
SSM.
    The information supporting this Executive Order review is contained
in section V.F of this preamble and in a technical report, Analysis of
Demographic Factors For Populations Living Near Steel Plants Using
Electric Arc Furnaces, located in the docket for this rule. Because the
EPA does not know where new facilities will be located that will become
subject to this new 40 CFR part 60, subpart AAb, a demographic analysis
was performed on the existing EAF/AOD population, which could become
subject to 40 CFR part 60, subpart AAb if a modification or
reconstruction increases emissions.

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 60

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

Michael S. Regan,
Administrator.
    For the reasons set forth in the preamble, the EPA amends 40 CFR
part 60 as follows:

PART 60--STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES

0
1. The authority citation for part 60 continues to read as follows:

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

Subpart A--General Provisions.

0
2. Section 60.17 is amended by revising paragraphs (g)(14), (h)(206),
and (j)(2) to read as follows:

Sec.  60.17  Incorporation by reference.

* * * * *
    (g) * * *
    (14) ASME/ANSI PTC 19.10-1981, Flue and Exhaust Gas Analyses [Part
10, Instruments and Apparatus], (Issued August 31, 1981), IBR approved
for Sec. Sec.  60.56c(b); 60.63(f); 60.106(e); 60.104a(d), (h), (i),
and (j); 60.105a(b), (d), (f), and (g); 60.106a(a); 60.107a(a), (c),
and (d); 60.275(e); 60.275a(e); 60.275b(e); tables 1 and 3 to subpart
EEEE; tables 2 and 4 to subpart FFFF; table 2 to subpart JJJJ;
Sec. Sec.  60.285a(f); 60.396(a); 60.2145(s) and (t); 60.2710(s) and
(t); 60.2730(q); 60.4415(a); 60.4900(b); 60.5220(b); tables 1 and 2 to
subpart LLLL; tables 2 and 3 to subpart MMMM; Sec. Sec.  60.5406(c);
60.5406a(c); 60.5407a(g); 60.5413(b); 60.5413a(b); and (d).
* * * * *
    (h) * * *
    (206) ASTM D7520-16, Standard Test Method for Determining the
Opacity of a Plume in the Outdoor Ambient Atmosphere, approved April 1,
2016; IBR approved for Sec. Sec.  60.271(k); 60.272(a) and (b);
60.273(c) and (d); 60.274(h); 60.275(e); 60.276(c); 60.271a; 60.272a(a)
and (b); 60.273a(c) and (d); 60.274a(h); 60.275a(e); 60.276a(f);
60.271b; 60.272b(a) and (b); 60.273b(c) and (d); 60.274b(h);
60.275b(e); 60.276b(f); 60.374a(d).
* * * * *
    (j) * * *
    (2) EPA-454/R-98-015, Office of Air Quality Planning and Standards
(OAQPS), Fabric Filter Bag Leak Detection Guidance, September 1997,
https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=2000D5T6.PDF; IBR approved
for Sec. Sec.  60.273(e); 60.273a(e); 60.273b(e); 60.373a(b);
60.2145(r); 60.2710(r); 60.4905(b); 60.5225(b).
* * * * *

Subpart AA--Standards of Performance for Steel Plants: Electric Arc
Furnaces Constructed After October 21, 1974, and On or Before
August 17, 1983

0
3. Section 60.270 is amended by revising paragraph (b) to read as
follows:

Sec.  60.270  Applicability and designation of affected facility.

* * * * *
    (b) The provisions of this subpart apply to each affected facility
identified in paragraph (a) of this section that commenced
construction, modification, or reconstruction after October 21, 1974,
and on or before August 17, 1983, where a modification is any physical
change in, or change in the method of operation of, an existing
facility which increases the amount of any air pollutant (to which this
standard applies) emitted into the atmosphere by that facility or which
results in the emission of any air pollutant (to which this standard
applies) into the atmosphere not previously emitted.

0
4. Section 60.271 is amended by:
0
a. Revising paragraphs (a), (d) through (f), (i) through (k), (m), and
(n); and
0
b. Adding new paragraphs (p) through (r).
    The revisions and additions read as follows:

Sec.  60.271  Definitions.

* * * * *

    (a) Electric arc furnace (EAF) means a furnace that produces molten
steel and heats the charge materials with electricity using carbon
electrodes. Furnaces that continuously feed direct-reduced iron ore
pellets as the primary source of iron are not affected facilities
within the scope of this definition.
* * * * *
    (d) Capture system means the equipment (including ducts, hoods,
fans, dampers, etc.) used to capture particulate matter generated by
the operation of an EAF and transport captured particulate matter to
the air pollution control device.
    (e) Charge means the addition of iron and steel scrap or other
materials into the shell of an electric arc furnace.
    (f) Charging period means the time period when iron and steel scrap
or other materials are added into the top of an EAF until the melting
and refining period commences.
* * * * *
    (i) Melting and refining means that phase of the steel production
cycle when charge material is melted and undesirable elements are
removed from the metal.
    (j) Melting and refining period means the time period commencing at
the initial energizing of the electrode to begin the melting process
and ending at the initiation of the tapping period, excluding any
intermediate times when the electrodes are not energized as part of the
melting process.
    (k) Shop opacity means the arithmetic average of 24 or more opacity
observations of any EAF emissions emanating from, and not within, the
shop, taken in accordance with EPA Method 9 of appendix A of this part.
Alternatively, ASTM D7520-16 (incorporated by reference, see Sec.
60.17), may be used with the following five conditions: (1) During the
digital camera opacity technique (DCOT) certification procedure
outlined in Section 9.2 of ASTM D7520-16 (incorporated by reference,
see Sec.  60.17), the owner or operator or the DCOT vendor must present
the plumes in front of various backgrounds of color and contrast
representing conditions anticipated during field use such as blue sky,
trees, and mixed backgrounds (clouds and/or a sparse tree stand);
    (2) The owner or operator must also have standard operating
procedures in place including daily or other frequency quality checks
to ensure the equipment is within manufacturing specifications as
outlined in Section 8.1 of ASTM D7520-16 (incorporated by reference,
see Sec.  60.17);
    (3) The owner or operator must follow the recordkeeping procedures
outlined in Sec.  60.7(f) for the DCOT certification, compliance