background concentrations that should vary seasonally to be in line
with monitored observations. As a result, Cliffs concluded that the
NOX emission reductions that will accompany the installation
of BART are being improperly credited with visibility improvements that
will not occur in the Minnesota and Michigan Class I areas. Finally,
Cliffs cited real-world monitor studies as evidence that large sources
that curtailed or shut down operations had little effect on visibility
monitors. The first of these studies evaluated the changes in
visibility monitoring at the Boundary Waters during periods of low
operation at the taconite facilities during 2009. The second study
evaluated changes in visibility monitoring at the Grand Canyon after
shutdown of the Mohave Power Plant.
    Response: EPA disagrees with these purported flaws in our approach,
many of which have been raised in the context of other states' BART
determinations. Regarding the issue of natural background conditions,
similar issues were addressed in EPA's action on the North Dakota
regional haze SIP (77 FR 20909, April 6, 2012). EPA recognizes that
variability in natural sources of visibility impairment cause
variability in natural haze levels as described in the Agency's
``Guidance for Estimating Natural Visibility Conditions under the
Regional Haze Rule.'' \24\ Progress toward natural visibility in Class
I areas includes improvement toward natural conditions for the 20
percent worst days and no degradation of visibility on the 20 percent
best days. The use of the 20 percent worst days in the calculation of
the uniform rate of progress takes into consideration visibility
impairment from wild fires, windblown dust, and other natural sources
of haze. For the evaluation of visibility impacts for BART sources,
however, EPA recommends using the natural visibility baseline for the
20 percent best days for comparison to the ``cause or contribute''
applicability thresholds. This estimated baseline is reasonably
conservative and consistent with the goal of attaining natural
visibility conditions. While EPA recognizes that there are natural
sources of haze, the use of the 20 percent worst days is inappropriate
for the ``cause or contribute'' applicability thresholds. For example,
if visibility impacts were evaluated in comparison to days with very
poor natural visibility resulting from nearby wild fires or dust
storms, the impacts of BART sources would be significantly reduced
relative to these

poor natural visibility conditions and would not be protective of
natural visibility on the 20 percent best days.\25\
---------------------------------------------------------------------------

    \24\ Guidance for Estimating Natural Visibility Conditions Under
the Regional Haze Rule, U.S. Environmental Protection Agency
(September 2003), available at http://www.epa.gov/ttncaaa1/t1/memoranda/rh_envcurhr_gd.pdf. ``Natural visibility conditions
represent the long-term degree of visibility that is estimated to
exist in a given mandatory Federal Class I area in the absence of
human-caused impairment. It is recognized that natural visibility
conditions are not constant, but rather they vary with changing
natural processes (e.g., windblown dust, fire, volcanic activity,
biogenic emissions). Specific natural events can lead to high short-
term concentrations of particulate matter and its precursors.
However, for the purpose of this guidance and implementation of the
regional haze program, natural visibility conditions represents a
long-term average condition analogous to the 5-year average best-
and worst-day conditions that are tracked under the regional haze
program.'' Guidance at 1-1.
    \25\ As part of the settlement of a case brought by the Utility
Air Regulatory Group challenging the BART Guidelines, EPA agreed to
issue guidance clarifying that states may use either the 20 percent
best days or the annual average in estimating natural visibility in
the evaluation of a BART source's impacts. This guidance makes clear
that states have the flexibility to use either approach in
estimating natural background conditions. Here, the states were not
required to use the annual average and did not. Similarly, in
issuing a FIP, EPA is not required to use the annual average either
and chose not to in this case.
---------------------------------------------------------------------------

    In regards to Cliffs' comment on atmospheric chemistry, the
approach used by EPA in the proposed rule relied on regional-scale
modeling conducted by MPCA where ammonia values varied temporally and
spatially. This is in contrast to the approach used in the CALPUFF
modeling submitted by Cliffs where a constant 1 ppb monthly average
ammonia value was used. While ammonia data is not available for the
vicinity of the sources of interest, data is available for sites
located in the Class I areas (Fernberg, MN) as well as for sites to the
south more representative of northern Wisconsin and southern
Minnesota.\26\ The available Fernberg ammonia data includes several
years of information and has an overall two-week average value of about
0.5 ppb with several two-week periods over 1 ppb. The Perkinstown site
located in northern Wisconsin is in an area combining forest,
grassland, and agricultural uses and has an overall two-week average
ammonia concentration of about 1.5 ppb with several two-week periods
over 1.5 ppb. Consequently, the value of 1 ppb used in the modeling
submitted by Cliffs is most likely representative of the ammonia
concentration in the vicinity of the sources of interest. However, EPA
again reiterates that Cliffs' largely baseless criticism of CALPUFF
does not apply to the Agency's ratio approach, which relied on
regional-scale modeling conducted by the states that included temporal
and spatial variations in ammonia concentrations.
---------------------------------------------------------------------------

    \26\ National Atmospheric Deposition Program, http://nadp.sws.uiuc.edu/AMoN/sites/data/.
---------------------------------------------------------------------------

    Finally, regarding Cliffs' comment concerning the two monitoring
studies, EPA does not find either of the studies to be persuasive with
respect to the impacts of taconite sources on visibility. The first
study asserts that the 2009 decline in taconite production and a
negligible change in visibility are evidence that further controls are
not warranted. EPA believes that that it is very difficult to discern
any effect from a one-year study and points out that the production
decline (as shown in Table 6 below) occurred during the spring and
summer, seasons for which Cliffs recognized that nitrate formation is
less important.

           Table 6--Minnesota 2009 Pellet Production by Month
                               [Tons] \27\
------------------------------------------------------------------------
                                                              Pellet
                          Month                             production
                                                              (tons)
------------------------------------------------------------------------
January.................................................       2,205,578
February................................................       1,900,003
March...................................................       1,620,343
April...................................................         958,479
May.....................................................         181,739
June....................................................         340,707
July....................................................         849,363
August..................................................       1,158,447
September...............................................       1,723,336
October.................................................       2,008,864
November................................................       2,038,844
December................................................       2,093,403
------------------------------------------------------------------------

    The second study Cliffs cited, which reviewed visibility monitoring
before and after the shutdown of the Mohave Power Plant in Nevada, is a
paper by Terhorst and Berkman (Atmospheric Environment, 2010). This
paper was subsequently examined and commented on in a paper by White et
al. (Atmospheric Environment, January 2012). There, White et al. state:
``[Terhorst and Berkman]'s technical analysis is thoughtfully conceived
and executed, but is misleadingly presented as discrediting previous
studies and their interpretation by regulators. In reality the
Terhorste Berkman analysis validates a consensus on MPP's (Mohave Power
Project) visibility impact that was established years before its
closure, in a collaborative assessment undertaken jointly by Federal
regulators and MPP's owners.'' Additionally, EPA has responded to
similar comments regarding the Mohave Power Project study and EPA's
visibility modeling in our action on the North Dakota regional haze SIP
(77 FR 20894, April 6, 2012).\28\
---------------------------------------------------------------------------

    \27\ Source: Minnesota Department of Revenue, Minerals Tax
Division, Eveleth, MN.
    \28\ There, EPA stated: ``In addition, the study by Terhorst and
Berkman does not convince us that use of CALPUFF modeling is
inappropriate for this action or that the CALPUFF modeling results
should be ignored. A model such as CALPUFF essentially holds
constant a number of factors in order to isolate the impacts of a
single source. As acknowledged by the study's authors, it is
extremely difficult in observational analyses to sufficiently
control for all factors, including emissions from other sources, to
be able to isolate the impacts of closure of a facility, especially
one located over 100 km from the Class I area at issue. In fact, the
paper notes that coarse soil mass impacts are an omitted variable in
the analytical analysis and that changes in those emissions may have
counteracted the visibility improvements expected from the source
shutdown'' (77 FR 20894, 20910).
---------------------------------------------------------------------------

    Finally, EPA believes that Cliffs, while identifying purported
areas where EPA's models exaggerate visibility impacts, overlooks that
there are aspects of the models that have been suggested by commenters
on our regional haze actions as under-predicting impacts. Some examples
include use of 24-hour average emissions impacts. Some examples include
use of 24-hour average emissions rather than hourly emissions, use of
monthly average relative humidity rather than daily humidity, and use
of 98th percentile results to compare to the threshold instead of the
highest day.
    Commenter: Cliffs Natural Resources and ArcelorMittal Minorca Mine.
    Comment: Cliffs commented that certain control options should be
rejected because visibility modeling does not indicate the installation
of controls will result in a perceptible visibility improvement.
    Response: EPA's disagrees. As explained in the proposed rule, EPA
believes that the application of BART will result in perceptible
improvements in visibility. Nonetheless, the perceptibility of
visibility improvement is not a prerequisite to the selection of a
control option as BART. The preamble to the BART Guidelines state,
``Even though the visibility improvement from an individual source may
not be perceptible, it should still be considered in setting BART
because the contribution to haze may be significant relative to other
source contributions in the Class I area. Thus, we disagree that the
degree of improvement should be contingent upon perceptibility'' (70 FR
39104, 39129, July 6, 2005).
    Minnesota's regional haze SIP described the importance of the
contribution of sources in northeastern Minnesota to visibility
impairment in the Boundary Waters and Voyageurs national parks.
Accordingly, Minnesota developed a special plan for the northeast
region of the state. Minnesota explained:

    This area was targeted for controls under the long-term strategy
for several reasons. First, the MPCA's analysis of 2002 emissions
from the top 18 emitting point sources within Minnesota show that
sources from this region make up just \1/3\ of the total emissions
but provide \2/3\ of the total visibility impact. (See Chapter 8, on
modeling.) Therefore, they have a much larger impact on the Class I
areas than emissions from farther away. In addition, the taconite
facilities may be currently uncontrolled or under-controlled for
SO2 or NOX, and on the books control
strategies are projected to cause fewer

emission decreases in this region than in the remainder of the
state.\29\
---------------------------------------------------------------------------

    \29\ Minnesota's 2009 regional haze SIP submittal at 96 (Docket
 EPA-R05-OAR-2010-0037-0002).

Thus, Minnesota's assessment supports the determination that taconite
facilities contribute to regional haze even if individual impacts are
modeled below thresholds for human perceptibility.

K. Comments Concerning Requirements for Continuous Emissions Monitoring

1. Comments in Support of Continuous Emissions Monitoring Requirements
    Commenter: National Parks Conservation Association.
    Comment: EPA's proposed rule includes the use of CEMS as a part of
the monitoring, recordkeeping, and reporting necessary to ensure the
continuous application of BART. Such monitors provide more accurate
data about the emissions from taconite facilities than previous
methods. As such, they are essential for tracking emissions and
determining their impact on the surrounding communities. Moreover, CEMS
can be used as pollution control tools by helping to fine-tune
combustion and process controls in a way that periodic stack tests and
predictive monitoring cannot. As such, we fully support the required
application of CEMS on these sources.
    Commenter: National Park Service.
    Comment: NPS is especially pleased that EPA has proposed testing
and CEMS requirements for the subject taconite plants. Our discussions
with U.S. Steel, which has led the way in installation and operation of
CEMS on indurating furnaces, have led to the mutual agreement that CEMS
data is essential for the proper tuning and operation of combustion
controls to reduce NOX emissions. Minnesota's regional haze
SIP discussed the need for requiring CEMS for the taconite industry to
monitor NOX for a number of reasons. These included setting
BART limits, allowing facilities to efficiently manage combustion,
resulting in less fuel use and fewer emissions, and tracking progress
under the Northeast Minnesota Plan. CEMS data is also essential for
assessing the effectiveness of SO2 controls and should
provide an indication of changes in fuel use or sulfur content for use
in future regional haze planning.
    Commenter: Leech Lake Band of Ojibwe.
    Comment: The Band agreed with the implementation of CEMS. CEMS will
provide the facility and regulators with real time data to ensure that
the controls in place are operating at optimum levels, thus saving
money for the facility and achieving the required control requirements.
    Commenter: National Tribal Air Association.
    Comment: The Association found requiring CEMS to be a good
complement to the NOX and SO2 controls at
taconite ore processing facilities. CEMS will provide these facilities
with an accurate and timely emissions count of NOX and
SO2 and will immediately alert owners to any deviations from
such emissions that might require correction.
    Response: EPA acknowledges the comments in support of the proposed
CEMS requirements. EPA is finalizing the CEMS requirements as proposed.
2. Comments Questioning EPA's Continuous Emissions Monitoring
Requirements
    Commenter: U.S. Forest Service.
    Comment: In the Minnesota regional haze SIP, a statement is made
that CEMS ``would apply to NOX emissions at the facilities
burning natural gas and to SO2 emissions at facilities
burning high sulfur fuels.'' We do not understand why the
NOX CEMs are only being required at natural gas-fired
furnaces. Those furnaces burning fuels other than natural gas will also
investigate NOX control strategies and therefore will need
the CEMs.
    Response: EPA is requiring CEMS for all seven subject-to-BART
taconite facilities. Each taconite facility must monitor its
NOX and SO2 emissions with CEMS.
    Commenter: U. S. Steel and Cliffs Natural Resources.
    Comment: Cliffs and U.S. Steel stated that it is inappropriate to
require the use of a diluent monitor as part of the monitoring
requirements under the proposed rule.
    Response: The need to install a diluent monitor is source-specific
and depends on a variety of factors, including the choice of monitors
installed. While some subject-to-BART facilities may not need to
install a diluent monitor, other facilities may because of their stack
characteristics, operating conditions, and monitors chosen. Because the
final rule covers a variety of facilities, EPA feels it is appropriate
to require a diluent monitor only for those facilities needing such a
unit. Therefore, the final rule has been revised to provide the
facilities with an option to demonstrate in their monitoring plans
whether a diluent monitor is needed or not.
    Commenter: Cliffs Natural Resources and ArcelorMittal Minorca Mine.
    Comment: Cliffs commented that EPA failed to adequately support its
CEMS requirements and that EPA should allow flexibility in the
monitoring requirements. More specifically, EPA should require ``a
comparable method of emission estimation,'' such as parametric
emissions monitors, for each subject-to-BART source. Cliffs stated that
EPA's unsupported generalized statements do not provide adequate
justification for the Agency's burdensome monitoring determination.
    Response: EPA clearly states in its technical support for the
proposed rule that CEMS are the best method for demonstrating
compliance because of the variability in furnace operations and
variable fuel usage across the furnaces. The variable fuel feeds and
feed material content can impact overall emissions from the process and
thereby create the need for continuous monitoring of emissions that
impact visibility. Parametric emissions monitor systems are an option
for processes that operate at stable, non-variable conditions, but are
not appropriate for taconite units. CEMS provide a continuous record of
data that can also be used by the facility owner or operator to monitor
emissions on a real-time basis. The installation and operation of CEMS
and the real-time evaluation of the CEMS data provide several benefits
to a facility that can directly lead to practices that reduce emissions
during all periods of operation.
    Commenter: Cliffs Natural Resources and ArcelorMittal Minorca Mine.
    Comment: Cliffs commented that CEMS do not constitute proven
monitoring technology with respect to taconite furnaces.
    Response: EPA disagrees. CEMS technology for NOX and
SO2 is proven in multiple industries, including the taconite
industry. U.S. Steel is successfully using CEMS at its Minntac and
Keetac facilities currently, and any problems experienced with the
initial installation of CEMS have been resolved. EPA expects facilities
will need some time to learn CEMS operation and how it impacts process
operations. EPA has incorporated additional time into the final rule
before certification is required to allow each facility to learn how
CEMS operates.
    Commenter: Cliffs Natural Resources and ArcelorMittal Minorca Mine.
    Comment: Cliffs asserted that the requirement to install CEMS
should be limited to waste stacks. Cliffs proposed to use stack testing
data to determine the percent distribution of NOX between
the hood-exhaust header and the waste-gas header to determine
compliance. Cliffs also stated that the use of a single

CEMS per furnace is consistent with Minntac, which currently utilizes
NOX and SO2 CEMS only.
    Response: EPA disagrees with Cliffs that the use of CEMS should be
limited to waste stacks only. Available information shows that
emissions from hood-exhaust stacks can equal about 29 percent of total
furnace emissions. Given that nearly one-third of the furnace emissions
are from hood exhausts (and can vary), EPA believes that it is
appropriate to require CEMS on both waste stacks and hood-exhaust
stacks.
    Cliffs incorrectly assumed that CEMS are required at each stack
venting to the atmosphere. EPA feels it is important to obtain
continuous and representative measurements of emissions from subject-
to-BART units. If representative measurements of total emissions from
subject-to-BART units can be obtained by installing CEMS in a single
vent just prior to the common header for the waste-gas stacks and hood-
exhaust stacks, then this final rule requires only two CEMS on each
stack (one NOX CEMS and one SO2 CEMS) for a total
of four CEMS, not ten. The initial monitoring plans required by this
final rule will be prepared by the facilities and will provide a means
through which an effective monitoring program will be put into place.
These plans should include proposals for CEMS types, CEMS numbers, CEMS
installation locations, QA/QC procedures, and any other topics and are
submitted to EPA for review and approval or disapproval. The
installation locations provided in these plans shall be determined
based on the requirements of 40 CFR part 60, appendices B and F.
    Commenters: Cliffs Natural Resources and ArcelorMittal Minorca
Mine.
    Comment: Cliffs commented that requiring CEMS on emergency stacks
is inappropriate.
    Response: The requirement to install CEMS on emergency stacks
depends on the frequency and duration of the use of the emergency
stacks during emergency events. If emergency stacks are used on a daily
or weekly basis, then emissions from those stacks could have an impact
on annual emissions (and visibility) and should be tracked and
recorded. If emergency stacks are truly used infrequently for quick
releases, then a CEMS may not be necessary. This can be addressed by
each facility on a case-by-case basis in its monitoring plan.
    Commenters: Cliffs Natural Resources and ArcelorMittal Minorca Mine
    Comment: Cliffs stated that the subject-to-BART facilities should
be exempt from the applicable emission limits during startup, shutdown
and malfunction events.
    Response: EPA disagrees. The CAA requires sources to comply with
applicable emission limits at all times, including during startup,
shutdown and malfunction. See, e.g., Sierra Club v. EPA, 551 F.3d 1019,
1021 (DC Cir. 2008); US Magnesium, LLC v. EPA, 690 F.3d 1157, 1170
(10th Cir. 2012).
    Commenter: Cliffs Natural Resources and ArcelorMittal Minorca Mine
and U.S. Steel.
    Comment: Cliffs commented that the requirement to develop and
implement a corrective action program for excess emission events should
be directed toward the emissions unit and not be part of the CEMS
requirement.
    Response: EPA agrees that the corrective action plan for excess
emission events should be directed toward the emissions unit. The
corrective action plan should establish procedures that operators will
follow each time an excess emission event occurs (as identified through
the use of real-time CEMS data). These procedures should outline steps
to adequately identify causes of excess emissions, actions to be taken
to minimize or eliminate those emissions, and evaluate and implement
practices to prevent the causes of such excess emissions from
reoccurring. The corrective action plan can be an independently
developed plan or the procedures can be incorporated into an existing
Quality Control Program Plan, corrective action plan, or other existing
standard operating plan.
    Commenter: Cliffs Natural Resources and ArcelorMittal Minorca Mine.
    Comment: Cliffs commented that the dates proposed for installing
CEMS are infeasible and suggested an alternative compliance period of
18 months.
    Response: EPA disagrees with the length of time Cliffs asserted is
needed to design and install CEMS. EPA recognizes that a certain period
of time will be needed if significant upgrades to stacks are necessary.
However, the design and installation of a CEMS can be completed far
more rapidly than the 18-month period suggested by Cliffs. EPA also
believes it is inappropriate to consider the time needed for CEMS
installation in a cumulative sequential manner as suggested by Cliffs.
Design, engineering requirements, and upgrades to data acquisition
systems can be performed at the same time as other activities required
by the proposed rule.
    EPA also recognizes that once CEMS are installed and operating,
there will be a short period of time needed to optimize and become
familiar with the system in order to certify the units. EPA believes
that the entire process for CEMS installation can be successfully met
within the time periods outlined in the proposed rule. However, in
response to the comments received, the final rule provides an
additional 30 days to certify the CEMS and perform the initial Relative
Accuracy Test Audit of the CEMS. The anticipated dates for initial
certification and the Relative Accuracy Test Audit must be included in
the monitoring plan required by the rule.
    Commenter: U.S. Steel.
    Comment: U.S. Steel commented that it is overly burdensome to
require redundant or backup monitoring systems to obtain emissions data
during periods of primary CEMS breakdown, repair, calibration check, or
zero span adjustment. U.S. Steel proposed to use data gap-filling
procedures during those periods when data are not available from the
CEMS due to these types of events.
    Response: The purpose of including the requirement to use ``other
monitoring systems approved by EPA'' is to obtain real-time emissions
data during periods of primary CEMS breakdown, repair, calibration
check, or zero span adjustment. The secondary data can be used to
assure data availability and compliance on a continuous basis. However,
the requirement for ``other monitoring systems'' does not mean that a
second CEMS system is necessarily needed. Because the duration of these
CEMS downtime events is typically short, each subject-to-BART facility
can submit proposals for using parametric monitoring or engineering
estimates as a surrogate for actual emissions monitoring during these
CEMS events. EPA expects that CEMS will be operated at all times,
including periods of process unit startup, shutdown and malfunction,
except during the events identified above as described at 40 CFR
60.13(e).
    EPA also disagrees with the suggestion that gap-filling procedures
(i.e., data substitution) should be used for periods of CEMS downtime.
Gap-filling procedures are appropriate under 40 CFR part 75 because it
is a cap-and-trade program. This final rule is more appropriately
related to regulations at 40 CFR part 60, where compliance with an
emission limit (rather than annual caps) is required. 40 CFR part 60
prohibits the use of ``data substitution'' (i.e., gap-filling) because
it does not provide accurate emission rates during the CEMS downtime.
    Commenter: U.S. Steel.
    Comment: U.S. Steel commented that it is not appropriate to require
initial performance testing of subject-to-BART

facilities or units if the facility is operating a certified CEMS
system on the affected units.
    Response: EPA has re-evaluated the need for initial performance
testing and agrees with U.S. Steel that it is not necessary to require
such testing, for purposes of this rule, at facilities that are or will
be operating CEMS when those CEMS will be used to determine compliance.
The requirement for initial performance testing has been removed from
the final rule. It is important to note that while initial performance
testing is being removed for purposes of demonstrating compliance,
subject-to-BART units must still be tested as part of the CEMS
certification process, although this the certification process will
typically not require a 30-day test.

L. Comments Concerning Compliance Schedules

    Commenter: Leech Lake Band of Ojibwe.
    Comment: The Band supported the installation of low NOX
burners and felt that the 1.5 years allowed for the initial
installation, with additional burner installations to follow one year
later, is a fair and progressive approach to control NOX
emissions.
    Response: EPA agrees with the commenter that installing low
NOX burners is the appropriate approach. In response to
additional information submitted by other commenters, however, EPA
reviewed the proposed installation schedule has extended it by a number
of months in the final rule, as discussed in more detail below.
    Commenter: Cliffs Natural Resources and ArcelorMittal Minorca Mine.
    Comment: Cliffs commented that the BART Guidelines require the
states, or EPA when promulgating a FIP, to establish deadlines for
compliance with BART emission limits no later than five years from the
date of approval or promulgation. EPA's proposed rule, however,
contains arbitrary compliance deadlines that are unreasonably short.
Cliffs stated that it would take at least four and a half years for it
to complete the required engineering, installation, and commissioning
of low NOX burners for a single furnace. ArcelorMittal
stated that ``a minimum of 48 months would be necessary to complete
this onerous process'' for its Minorca Mine facility.
    Response: CAA section 169A(b)(2)(A) requires subject-to-BART
sources to install BART and comply with any applicable emission limits
``as expeditiously as practicable.'' The Act defines this term to mean
``as expeditiously as practicable but in no event later than five years
after * * * the date of promulgation.'' CAA section 169A(g)(4). This
language does not indicate that a compliance schedule of five years is
to be assumed. Rather, BART must be installed ``as expeditiously as
practicable,'' meaning as soon as the source is capable of installing
the controls and meeting the applicable emission limits.
    In response to EPA's request for a detailed timeline of the steps
required to install low NOX burners on a taconite furnace,
U.S. Steel provided the following information based on its actual
experience with a previous install:

           Table 7--U.S. Steel's Estimate Compliance Schedule
------------------------------------------------------------------------
                Task                                 Time
------------------------------------------------------------------------
Detailed low NOX burner engineering.  6 months.
Prepare permit applicability          2 months.
 determination.
Procure and manufacture low NOX       8 months.
 burner.
Install low NOX burner..............  3 weeks.
                                     -----------------------------------
Shakedown of low NOX burner.........  6 months.
    Total time......................  22 months, 3 weeks.
------------------------------------------------------------------------

    In addition to this information, ArcelorMittal included an
attachment to its comments of a September 27, 2012 report by Fives
North American titled ``Retrofitting Low NOX Burners on the
ArcelorMittal Minorca Straight-Grate Pelletizing Furnace.'' In that
report, Fives states that to develop an engineering solution that
complies with environmental requirements, it is important to allow
sufficient time (approximately four to eight months) for engineering
analysis and (possibly) testing. The schedule should allow for an
additional seven months for fabrication and delivery, followed by an
additional two months for installation and commissioning. This amounts
to an estimated time of 17 months to achieve compliance.
    Based on the timeline provided by U.S. Steel, the vendor estimate
from Fives, and concerns from the commenters, EPA is allowing 26 months
for a company's first indurating furnace to comply with the final rule.
This will allow each source sufficient time to perform an engineering
analysis, prepare a permit applicability determination, manufacture and
install the low NOX burner, and allow for a shakedown period
to achieve compliance after the low NOX burner has been
installed. This is eight months longer than the proposed compliance
schedule, allowing for the additional time needed for a shakedown
period.
    The compliance schedule for additional indurating furnaces is being
finalized as proposed. Specifically, a second line has an additional
year to comply, for a total of 38 months from the effective date of the
rule. A third line has two additional years to comply, for a total of
50 months from the effective date of the rule. This staggered
installation schedule will minimize any potential impacts on
production. EPA notes that U.S. Steel Minntac is following a shorter
schedule consistent with the proposed rule. U.S. Steel Keetac will also
follow a modified schedule. For more detail, see the comment below.
    Commenter: U.S. Steel.
    Comment: Due to the lead time associated with acquiring process
fans at Keetac, which is estimated to be 52 weeks according to a third-
party engineering firm working on the project, and the timing of the
major outage schedule, which only occurs once per year, the potential
exists to miss the timing window where the two sync up to meet the
proposed schedule. Therefore, U.S. Steel requests an additional 12
months to the proposed schedule for installation. In addition, because
this will be the first installation of this technology at Keetac, U.S.
Steel requests an additional 6 months prior to compliance with the
proposed emission limit to allow for a shakedown period to optimize the
burner for NOX reductions.
    Response: EPA agrees with U.S. Steel that additional time is needed
to procure new pre-heat fans and to achieve compliance after
installation. In the final rule, Keetac has three years (36 months from
the effective date of the

rule) for its single line to comply with the rule.
    Commenter: U.S. Steel.
    Comment: Due to timing of major outage schedules, U.S. Steel
requests flexibility in the order of installation for Line 4 and Line 5
at Minntac. U.S. Steel agrees with the overall intent of the proposed
schedule, but requests the option to select the order of installation
of low NOX burners at Lines 4 and 5.
    Response: EPA agrees with the U.S. Steel's request to leave to the
discretion of U.S. Steel the order of installation of low
NOX burners at Lines 4 and 5 at Minntac.

M. Comments Asserting That EPA Must Conduct Government-to-Government
Consultation With the Tribes

    Commenter: National Tribal Air Association (NTAA).
    Comment: The Association understands that at the request of the
Fond du Lac Band, EPA held a June 28, 2012 conference call with the
region's Tribes to discuss the FIP. We appreciate EPA for doing this
and highly recommend that the Agency hold similar calls with Tribes for
other such actions. However, EPA must also honor its commitment to
conduct formal government-to-government consultation in accordance with
Executive Order (EO) 13175.
    The Association disagrees with EPA's statement that the FIP ``does
not have tribal implications, as specified in EO 13175. It will not
have substantial direct effects on tribal governments. Thus, EO 13175
does not apply to this rule.'' The application of BART to taconite ore
processing facilities that either are in close proximity to Tribes and
their communities or are within Treaty-ceded territory areas
maintaining Tribes' usufructary functions is a regulatory action that
has Tribal implications. As such, EPA must conduct formal government-
to-government consultation with Tribes.
    There are also clear purposes for EPA to conduct formal government-
to-government consultation with Tribes. First, it provides for more
candid conversations between individual Tribes and EPA than would occur
otherwise in a group meeting involving other Tribes. Second, each
Tribe's circumstances are unique and must be treated as such by EPA.
Group meetings would only give short shrift to these circumstances.
Third, most cultural resources information is protected from release
under statutory exemptions to the Freedom of Information Act.
Discussion of such information as part of a group meeting risks its
release to the general public and potentially endangers Tribal cultural
sites and practices. Finally, the subject matter may be so unique, such
as a dispute between an individual Tribe about whose cultural resources
might be located within or near a taconite ore processing facility,
that government-to-government consultation between the Tribe and EPA
could provide the best opportunity for a resolution to the situation
versus a group meeting where any number of issues might be discussed in
a finite period of time.
    Response: EPA acknowledges that this action may have tribal
implications. EPA recognizes that Tribes may have significant interests
in regulatory programs even if the potential Tribal impacts are not the
types specifically identified in the Executive Order. In this case, EPA
initiated consultation with Tribal officials early in the process of
developing this regulation to permit them to have meaningful and timely
input into its development. While the Tribes ultimately chose not to
engage in individual consultation, EPA did communicate with Tribal
representatives to ensure that information was made available and that
there was sufficient opportunity for questions and discussion. This
effort is described in further detail in Section IV of this final rule.
EPA appreciates the comments provided by the Tribes and NTAA on this
rule, which will benefit Tribes through reduced pollution and improved
visibility.

N. Comments Concerning Non-Air Quality Impacts of the Proposed Rule

    Commenter: Cliffs Natural Resources.
    Comment: Cliffs commented that significant environmental impacts
will result if the rule is finalized as proposed. Cliffs stated that
increased fuel combustion resulting from low NOX burner
application will result in increased emissions of the products of
combustion. Cliffs added that EPA's proposed SO2 controls
also carry ancillary environmental consequences.
    Response: EPA disagrees. The BART Guidelines recognize that
environmental concerns become important when sensitive site-specific
receptors exist and are impacted by byproducts of the control device.
However, the fact that a control device creates liquid and solid waste
that must be disposed of does not necessarily argue against that
technology as BART. In this case, there are no such sensitive, site-
specific issues. To avoid any such issues, EPA rejected the use of wet
SO2 scrubbing at taconite plants in Minnesota because
wastewater from wet scrubbing had the potential to interfere with the
production of wild rice.
    Commenter: National Tribal Air Association.
    Comment: The Association commented that Tribal traditional
practices will benefit by controlling NOX and SO2
emissions from taconite ore processing facilities. Such benefits
specifically relate to visibility, health, and acid deposition.
    Not only does regional haze, which the FIP addresses, reduce the
clarity, color, and visible distance that one can see, it marginalizes
Tribal traditional practices that have existed since time immemorial.
Many Tribes engage in traditional practices associated with sacred
mountains, lakes, or other places that hold significance to them. Some
of these practices are dependent on Tribal members being able to view
and honor such icons that may be located many miles from a Tribe's
lands.
    A corresponding effect of NOX and SO2
emissions on Tribal traditional practices is on the health of Tribal
members. Tribes are not immune from the health effects of
NOX and SO2, such as asthma, bronchitis, and
heart disease. In fact, they are more susceptible to these effects
based on lifestyles. Many Tribes and their members spend considerable
time outdoors engaged in Tribal traditional practices. Time-honored
practice precludes Tribal members from simply moving indoors during
high or moderate NOX or SO2 emission episodes.
Hence, they experience increased health effects due to their long-term
exposure to NOX and SO2. However, the FIP does
much to reduce their exposures to such emissions from taconite ore
processing facilities.
    Tribal traditional practices are also affected by acid deposition
for which NOX and SO2 serve as precursors. Upon
being emitted into the atmosphere, NOX and SO2
return to the Earth's surface is one of two ways. The first occurs when
these pollutants mix with water vapor in the atmosphere and are
subsequently converted into acids. This is known as wet deposition. The
second way occurs when NOX and SO2 form gases and
salts. These gases and salts can cling to basically anything, including
the ground, trees, and buildings. After they attach to an object, they
are converted into acids at the point where moisture in the air mixes
with them. Tribal foods, such as wild rice, can be contaminated by acid
deposition. Forest ecosystems, which are an integral part to Tribal
life, are susceptible to oxidation damage due to acid deposition and
ozone exposure. Acid deposition adversely affects everything in the
forest ecosystem, and the plants and animals on which a number of
Tribes subsist. The

petroglyphs (rock images) and other sacred sites of Tribes are also
susceptible to acid deposition and decay. The FIP helps to control acid
deposition that would otherwise occur due to the emissions of taconite
ore processing facilities. Undeniably, this will benefit the region's
Tribes.
    Response: While the focus of the regional haze program is to
improve visibility at Class I areas, the EPA agrees with the
Association that emission reductions made to improve visibility have
additional benefits. EPA agrees that Midwestern Tribes will benefit as
the regional haze program is implemented and emission reductions occur.
    Commenter: Leech Lake Band of Ojibwe.
    Comment: The Band commented about concerns related to the damage of
wild rice. Wild rice is extremely susceptible to sulfides where impacts
from these emissions can be currently observed. The effects of sulfide
degradation can have detrimental effects on Tribal Lifeways for this
important cultural and subsistence food source.
    Commenter: Red Cliff Band of Lake Superior Chippewas.
    Comment: Sulfur dioxide is a pollutant of special concern to the
Red Cliff Tribe due to its negative impacts on sensitive aquatic
organisms such as wild rice and its interaction with atmospherically
deposited mercury in aquatic systems. Reductions in SO2
could help to decrease the methylation of mercury in waters fished by
Red Cliff and reduce limitations on how much locally harvested fish
tribal members can safely consume.
    Response: EPA did consider the energy and non-air quality
environmental impacts as part of its BART determinations. EPA is aware
of the concerns regarding sulfur oxides in wastewater and the resulting
effect on wild rice. Accordingly, EPA considered the significance of
the potential impacts of wastewater releases while evaluating the
control technology options for the taconite facilities.
    Commenter: National Tribal Air Association.
    Comment: Tribes shoulder a disproportionate burden of the negative
environmental consequences caused by the operation of commercial and
industrial facilities. Most of these facilities are not located in
Tribal communities, but their emissions often find their way onto
Reservations and Ceded Territories. Such is the case for the taconite
ore processing facilities whose current emissions not only affect the
region's Tribes, but whose conversion to ozone could impact these
Tribes even further. The Association finds that the NOX
reductions required under the FIP will help address the problem of
ozone levels rising with respect to the taconite ore processing
facilities and will inhibit climate change albeit a small amount.
    Response: While emission reductions being required of the taconite
industry are solely to improve visibility at mandatory Class I areas,
EPA agrees that collateral benefits may also be achieved due to the
emission reductions. EPA did not attempt to identify or quantify these
additional potential benefits in this final rule.

O. Miscellaneous Comments

    Commenter: Red Cliff Band of Lake Superior Chippewas.
    Comment: The Northeast Minnesota Plan calls for a 30 percent
reduction in emissions of SO2 and NOX (regional
haze causing pollutants) from large emitters in this region by the year
2018, with an interim goal of a 20 percent reduction by the year 2012.
Minnesota's regional haze SIP states that these facilities are well on-
track for meeting these goals. However, over the past several years
there have been numerous applications for new mining projects in the
area. The Band is very concerned with maintaining the progress that has
already been achieved, so that Voyageurs National Park and the Boundary
Waters Canoe and Wilderness Area can meet their regional haze
Reasonable Progress Goals, as required in the Regional Haze Rule.
    Response: EPA gave final approval to many elements of the Minnesota
regional haze plan on June 12, 2012 (77 FR 34801). This approval
included the Northeast Minnesota Plan. EPA expects Minnesota to meet
the pollution reductions goals in the Plan, which may include needing
to offset any emission increases from new and expanding facilities with
deeper emission reductions from other facilities.
    Commenter: Fond du Lac Band of Lake Superior Chippewa.
    Comment: The Band commented that it was concerned how the taconite
facilities will meet the new hourly SO2 and NO2
National Ambient Air Quality Standards (NAAQS) that have recently been
issued by EPA. It is likely that at least some of these facilities will
need to install additional control equipment in order to be able to
demonstrate attainment with these new standards. The installation of
low NOX burners on the BART-eligible taconite sources
promises to be a good solution, both for achieving the one-hour
NO2 NAAQS and for reducing regional haze. Given the current
state of uncertainty as to how modeling for this one-hour standard
should be approached, it may be years before controls are required on
taconite furnaces as a solution to any modeled exceedances of the
NAAQS. The Band is concerned that this will cause delay in achieving
regional haze goals in this area. It is also possible that litigation
against or revocation of the NAAQS could further delay the area in
achieving these goals.
    Response: EPA agrees that control technology installed to meet BART
requirements for regional haze may also contribute to improvements in
ambient air quality.
    Commenter: Cliffs Natural Resources and ArcelorMittal Minorca Mine.
    Comment: Cliffs noted that it could not duplicate some of the delta
DV and delta days values listed in Tables V-C.10, V-C.11, and V-C.14 of
the proposed FIP.
    Response: Upon review of the values, EPA agrees with the Cliffs
that some of the delta DV and delta days values were incorrect in the
proposed rule. Specifically, some of the values listed in Tables V-C.5,
V-C.8, and V.C.9 were incorrect. Cliffs also noted that it could not
reproduce values in Tables V-C.10, V-C.11, and V-C.14. These values
were linked to values in the previous tables and also were listed
incorrectly. EPA regrets the errors, but overall, the corrections were
minor and did not change the conclusions reached. Corrected tables are
listed below.

  Table V-C.5--BART NOX and SO2 Emission Reductions and Modeled Visibility Impact/Emission Reduction Ratios for
                             Fine Particulates at Class I Areas for United Taconite
----------------------------------------------------------------------------------------------------------------
                                                                     Boundary
                            Parameter                                 waters         Voyageurs      Isle Royale
----------------------------------------------------------------------------------------------------------------
NOX Emissions Decrease ([Delta] NOX)............................                    0 tons/year
                                                                 -----------------------------------------------

SO2 Emissions Decrease ([Delta] SO2)............................                  1,837 tons/year
                                                                 -----------------------------------------------
[Delta] dv PM2.5................................................            -1.2            -0.8            -0.3
[Delta] dv PM2.5/[Delta] SO2....................................        -0.00065        -0.00043       -0.000016
[Delta] Days PM2.5..............................................             -10              -8              -3
[Delta] Days PM2.5/[Delta] SO2..................................         -0.0054         -0.0044         -0.0016
----------------------------------------------------------------------------------------------------------------

  Table V-C.8--BART NOX and SO2 Emission Reductions and Modeled Visibility Impact/Emission Reduction Ratios for
                       Fine Particulates at Class I Areas for Northshore Mining-Silver Bay
----------------------------------------------------------------------------------------------------------------
                                                                     Boundary
                            Parameter                                 waters         Voyageurs      Isle Royale
----------------------------------------------------------------------------------------------------------------
NOX Emissions Decrease ([Delta] NOX)............................                   678 tons/year
                                                                 -----------------------------------------------
SO2 Emissions Decrease ([Delta] SO2)............................                   444 tons/year
                                                                 -----------------------------------------------
[Delta] dv PM2.5................................................            -0.2            -0.1            -0.2
[Delta] dv PM2.5/[Delta] NOX....................................        -0.00029        -0.00015        -0.00029
[Delta] DV PM2.5/[Delta] SO2....................................        -0.00045        -0.00023        -0.00045
[Delta] Days PM2.5..............................................              -5              -1              -3
[Delta] Days PM2.5/[Delta] NOX..................................         -0.0074         -0.0015         -0.0044
[Delta] Days PM2.5/[Delta] SO2..................................          -0.011         -0.0023         -0.0068
----------------------------------------------------------------------------------------------------------------

       Table V-C.9--Averaged Visibility Impact/Emission Change Ratios for Analyzed/Impacted Class I Areas
----------------------------------------------------------------------------------------------------------------
                                                                     Boundary
                         Parameter ratio                              waters         Voyageurs      Isle Royale
----------------------------------------------------------------------------------------------------------------
[Delta] DV PM2.5/[Delta] NOX....................................        -0.00061        -0.00030        -0.00042
[Delta] DV PM2.5/[Delta] SO2....................................        -0.00050        -0.00025        -0.00030
[Delta] Days/[Delta] NOX........................................         -0.0083          -0.004        -0.00524
[Delta] Days/[Delta] SO2........................................         -0.0067         -0.0030         -0.0037
----------------------------------------------------------------------------------------------------------------

    Table V-C.10--Estimated Emission Reductions and Resulting Changes in Visibility Factors for ArcelorMittal
----------------------------------------------------------------------------------------------------------------
                                                                     Boundary
       Visibility factor or pollutant emissions reduction             waters         Voyageurs      Isle Royale
----------------------------------------------------------------------------------------------------------------
NOX Emissions Reduction.........................................                  2,859 tons/year
                                                                 -----------------------------------------------
[Delta] DV......................................................            -1.7            -0.9            -1.2
[Delta] Days > 0.5 DV...........................................             -24             -11             -15
----------------------------------------------------------------------------------------------------------------

  Table V-C.11--Estimated Emission Reductions and Resulting Changes in Visibility Factors for Hibbing Taconite
----------------------------------------------------------------------------------------------------------------
                                                                     Boundary
       Visibility factor or pollutant emissions reduction             waters         Voyageurs      Isle Royale
----------------------------------------------------------------------------------------------------------------
NOX Emissions Reduction.........................................                  5,259 tons/year
                                                                 -----------------------------------------------
[Delta] DV......................................................            -3.2            -1.6            -2.2
[Delta] Days > 0.5 DV...........................................             -44             -21             -28
----------------------------------------------------------------------------------------------------------------

  Table V-C.12--Estimated Emission Reductions and Resulting Changes in Visibility Factors for U.S. Steel-Keetac
----------------------------------------------------------------------------------------------------------------
                                                                     Boundary
       Visibility factor or pollutant emissions reduction             waters         Voyageurs      Isle Royale
----------------------------------------------------------------------------------------------------------------
NOX Emissions Reduction.........................................                  2,908 tons/year
                                                                 -----------------------------------------------
[Delta] DV......................................................            -1.8            -0.9            -1.2

[Delta] Days > 0.5 DV...........................................             -24             -11             -15
----------------------------------------------------------------------------------------------------------------

    Commenter: Cliffs Natural Resources and ArcelorMittal Minorca Mine.
    Comment: References to the optional use of Part 75 recordkeeping
requirements should be removed from the proposed rule because taconite
furnaces are not Acid Rain subject units.
    Response: EPA intended to provide the Part 75 recordkeeping
requirements as an option for facilities electing to use those
recordkeeping requirements. If a subject-to-BART facility is not
subject to the Acid Rain requirements, then recordkeeping requirements
of either 40 CFR part 60 or 40 CFR part 63 may be used.
    Commenter: Cliffs Natural Resources, ArcelorMittal Minorca Mine,
and U.S. Steel.
    Comment: Cliffs and U.S. Steel noted that the reference to 40 CFR
163.3 is incorrect and should be revised to 40 CFR 136.3.
    Response: A correct citation is provided in the final rule.
    Commenter: Cliffs Natural Resources and ArcelorMittal Minorca Mine.
    Comment: Cliffs noted that the reference to 40 CFR part 60,
appendix B, Performance Specification 2, Procedure 1, is incorrect.
Procedure 1 should be associated with 40 CFR part 60, appendix F.
    Response: A correct citation is provided in the final rule.
    Commenter: Cliffs Natural Resources, ArcelorMittal Minorca Mine,
and U.S. Steel.
    Comment: Cliffs and U.S. Steel stated that the inclusion of
references to the General Provisions of 40 CFR part 63 is inappropriate
and overly burdensome. The references to 40 CFR part 63 should be
removed.
    Response: EPA included references to 40 CFR part 63 because many of
those requirements (including the development of a startup, shutdown
and malfunction plan and monitoring plan) should have already been
developed for the subject-to-BART facilities for purposes of the
Taconite MACT rule. Additionally, the requirements associated with the
installation, certification, maintenance, and operation of the CEMS are
similar. However, in response to the comments received, references to
40 CFR part 63 will be removed. References to 40 CFR part 60,
appendices B and F will be retained where appropriate. The rule has
also been revised to specifically identify requirements that we
intended to include (for example notifications or reporting), but which
were previously incorporated through citing to either 40 CFR part 60 or
40 CFR part 63.

III. What action is EPA taking?

    The emission sources discussed below are indurating furnaces at
seven taconite facilities. Six of the taconite facilities,
ArcelorMittal, Hibbing Taconite, Northshore Mining, U.S. Steel Keetac,
U.S. Steel Minntac, and United Taconite, are located in Minnesota,
while Tilden is located in Michigan. EPA has adopted the terminology
used by the companies and states to identify the indurating furnaces to
ensure consistency with permits and other enforceable documents.
However, regardless of whether the emission sources are referred to as
furnaces, kilns, or lines, all terms refer to indurating furnaces,
which involve a high temperature process for hardening taconite pellets
for subsequent use in blast furnaces.

A. NOX Limits

    EPA is revising its proposed limit of 1.2 lbs NOX/MMBTU,
on a 30-day rolling average, to a limit of 1.2 lbs NOX/MMBTU
when only natural gas is used and a limit of 1.5 lbs NOX/
MMBTU for all other fuels, on a 30-day rolling average, for all
indurating furnaces. These revised limits are based upon test data
submitted by U.S. Steel for Lines 6 and 7 at Minntac while using low
NOX burners. This revision affects U.S. Steel Keetac, U.S.
Steel Minntac, and United Taconite, which use solid fuel. The other
four facilities will be subject to the natural gas limit of 1.2 lbs
NOX/MMBTU. To meet these limits, the sources will
essentially be required to install low NOX burners on each
indurating furnace. Based upon information received during the comment
period, EPA believes that 26 months is a reasonable time for a
company's first indurating furnace to comply with the limit. This will
allow each company sufficient time to perform an engineering analysis,
prepare a permit applicability determination, manufacture and install
the low NOX burner(s), and provide for a shakedown period to
achieve compliance after the low NOX burner(s) have been
installed. While this compliance schedule is six months longer than the
proposal, EPA believes that the additional time is necessary for a
shakedown period.
    As specified in the proposal, a second line will have an additional
year to comply with the emission limit, while a third line will have
two additional years to comply. This approach will stagger the
installation and minimize impacts on production. EPA notes, however,
that U.S. Steel Minntac is on a shorter schedule consistent with what
was proposed, while U.S. Steel Keetac has been given three years to
comply with its only line. The additional time afforded to U.S. Steel
Keetac is primarily due to the lead time associated with acquiring
process fans.

B. SO2 Limits

    EPA is revising all of the proposed SO2 limits as
follows. Unless otherwise stated, these limits are based on the 95th
percentile UPL.
Tilden Mining Company
    Tilden's Grate Kiln Line 1 is required to convert to 100 percent
natural gas and install CEMS within one year of the effective date of
this rule. Within 26 months of the effective date of this rule, an
emission limit must be established, in terms of lbs SO2/hr,
on a 30-day rolling average, based on the 95th percentile UPL. This
compliance schedule allows two months to process 12 months of CEMS
data. This is a change from the proposed requirement to install an add-
on control system, achieving either 5 ppmv SO2 or 95 percent
removal efficiency, because such a control system is not economically
feasible when a furnace is using only natural gas.
U.S. Steel Keetac
    An emission limit of 225 lbs SO2/hr, based on a 30-day
rolling average, shall apply to U.S. Steel Keetac's Grate Kiln
pelletizing furnace beginning three months from the effective date of
the rule. This numerical limit and compliance schedule are the same as
those contained in the proposed rulemaking and reflect existing
controls. However, redundant control efficiency and pH limits have been
eliminated.

EPA has clarified in the final rule that, in addition to this
SO2 limit, any coal burned at Keetac must have a sulfur
content no greater than 0.60 percent sulfur by weight based on a
monthly block average.
Hibbing Taconite
    An aggregate emission limit of 247.8 lbs SO2/hr, based
on a 30-day rolling average, shall apply to the pelletizing furnaces at
Hibbing's three lines beginning six months from the effective date of
this rule. This limit reflects existing controls. This is an increase
from the proposed limit, which totaled 183 lbs SO2/hr, based
on a 30-day rolling average. This increase is a result of more accurate
emission data that was obtained subsequent to the proposal.
U.S. Steel Minntac
    An aggregate emission limit of 498 lbs SO2/hr shall
apply to indurating furnace Lines 3-7 when all lines are producing flux
pellets. An aggregate emission limit of 630 lbs SO2/hr shall
apply to Lines 3-7 when Lines 3-5 are producing acid pellets and Lines
6 and 7 are producing flux pellets. An aggregate emission limit of 800
lbs SO2/hr shall apply to Lines 3-7 when all lines are
producing acid pellets. These limits reflect existing controls. These
SO2 emission limits are based on a 30-day rolling average
and apply three months from the effective date of this rule. This is an
increase from the proposed limits, which totaled 327 lbs
SO2/hr, based on a 30-day rolling average. This increase is
a result of more accurate emission data that was obtained subsequent to
the proposal. EPA has clarified in the final rule that, in addition to
these SO2 limits, any coal burned at Minntac must have a
sulfur content no greater than 0.60 percent sulfur by weight based on a
monthly block average.
United Taconite
    An aggregate emission limit of 529 lbs SO2/hr, based on
a 30-day rolling average, shall apply to the Line 1 and Line 2 pellet
furnaces beginning 54 months from the effective date of this rule. In
addition to this limit, United Taconite is required to burn either
natural gas or a blend of natural gas and coal. Any coaled burned must
have a sulfur content no greater than 0.60 percent sulfur by weight
based on a monthly block average. This limit represents a change from
the proposed requirement to install an add-on control system, achieving
either 5 ppmv SO2 or 95 percent removal efficiency. Because
this federally enforceable operational change in fuel mixture will
achieve approximately a 50 percent reduction in the facility's baseline
and actual emissions, the proposed add-on control system is no longer
cost effective.
ArcelorMittal Minorca Mine
    An emission limit of 38.16 lbs SO2/hr, based on a 30-day
rolling average, shall apply to ArcelorMittal's indurating furnace
beginning six months from the effective date of this rule. This is an
increase from the proposed limit of 23 lbs SO2/hr, based
upon a 30-day rolling average. This increase is a result of more
accurate emission data that was obtained subsequent to the proposal.
Northshore Mining Company
    An aggregate emission limit of 39 lbs SO2/hr, based on a
30-day rolling, shall apply to Furnace 11 and Furnace 12, beginning six
months from the effective date of this rule. This limit will stay
effective for one year. This is an increase from the proposed limit of
33.4 lbs SO2/hr, based upon a 30-day rolling average. The
proposed control efficiency requirement has been eliminated because it
is a redundant requirement. Within 20 months of the effective date of
this rule, a revised SO2 limit must be established based on
one year of hourly CEMS data using the 95th percentile UPL.

C. CEMS

    As required in the proposal, installation and operation of CEMS is
required no later than the applicable compliance date for each limit.
This represents no change from the proposed rulemaking. However, as
indicated above, some compliance dates have been extended, and some
indurating furnaces are now subject to status-quo SO2
limits. Based upon comments received, as well as additional information
regarding the amount of time needed to install CEMS, we have increased
the compliance schedule from three months to six months for those
sources that are maintaining status quo controls and do not currently
have CEMS.

D. Visibility Benefits and Cost Effectiveness

    EPA estimates that this action will improve visibility at four
Class I areas by reducing about 22,000 tons per year of NOX
emissions and 2,000 tons per year of SO2 emissions from
seven taconite facilities. The reductions in NOX emissions
will result from the installation of low NOX burners, a
relatively inexpensive control device that does not involve significant
retrofit costs as the process consists primarily of switching out
burners. U.S. Steel Minntac is the only facility at which low
NOX burners have been installed and the only one for which
detailed cost information is available.

                       Table 8--Low NOX Burner Cost Analysis at U.S. Steel Minntac Line 6
----------------------------------------------------------------------------------------------------------------
                                                    Annualized                         Total           Cost-
           Fuel blend              Capital cost    capital cost   Annual O&M ($/    annualized     effectiveness
                                        ($)           ($/yr)            yr)         cost ($/yr)       ($/ton)
----------------------------------------------------------------------------------------------------------------
60% Coal/40% Natural Gas........      $2,846,422        $536,754        $228,293        $765,048            $441
100% Natural Gas................       2,846,422         536,754         228,293         765,048             210
----------------------------------------------------------------------------------------------------------------

    EPA believes that the costs cited by U.S. Steel are generally
applicable across the industry based on discussions the Agency had with
vendors. As a result, a figure of $500/ton was ultimately selected as a
conservative upper bound for the cost effectiveness of installations at
the other taconite facilities.
    Reductions in SO2 emissions will result from fuel
switching and new emission limits that properly reflect existing
SO2 controls. EPA did not have sufficient information to
estimate the costs of fuel switching.
Proposed Disapproval of the States' BART Determinations for Taconite
Facilities
    EPA reiterates that the Agency is not taking action today on its
proposed disapproval of Minnesota and Michigan's BART determinations
for the taconite industry. EPA is issuing a separate supplemental
notice of

proposed rulemaking that provides additional explanation of the
Agency's rationale for the proposed disapproval and solicits additional
comments. EPA will publish a separate final rulemaking regarding the
proposed disapproval once the Agency has completed review of any
additional public comments received.

IV. Statutory and Executive Order Reviews

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

    This action finalizes BART requirements for seven taconite
facilities in Minnesota and Michigan. Therefore, it is not a rule of
general applicability, and not a ``significant regulatory action''
under the terms of Executive Order 12866 (58 FR 51753, October 4,
1993). Because this type of action is exempt from review under EO
12866, it is also not subject to review under Executive Order 13563 (76
FR 3821, January 21, 2011).

B. Paperwork Reduction Act

    This action does not impose an information collection burden under
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq.
Burden is defined at 5 CFR 1320.3(b). Because this FIP only applies to
seven facilities in Minnesota and Michigan, the Paperwork Reduction Act
does not apply. See 5 CFR 1320.3(c).

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an Agency
to prepare a regulatory flexibility analysis of any rule subject to
notice and comment rulemaking requirements under the Administrative
Procedure Act or any other statute unless the Agency certifies that the
rule will not have a significant economic impact on a substantial
number of small entities. Small entities include small businesses,
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impacts of today's rule on small
entities, small entity is defined as: (1) A small business as defined
by the Small Business Administration's (SBA) regulations at 13 CFR
121.201; (2) a small governmental jurisdiction that is a government of
a city, county, town, school district or special district with a
population of less than 50,000; and (3) a small organization that is
any not-for-profit enterprise which is independently owned and operated
and is not dominant in its field.
    After considering the economic impacts of this action on small
entities, I certify that this action will not have a significant
economic impact on a substantial number of small entities. The net
result of this final action is that EPA is promulgating emission
controls on selected units at seven large taconite facilities that are
not owned by small entities, and therefore are not themselves small
entities.

D. Unfunded Mandates Reform Act (UMRA)

    This rule does not contain a Federal mandate that may result in
expenditures of $100 million or more for State, local, and tribal
governments, in the aggregate, or the private sector in any one year.
It is a rule of particular applicability that affects only seven
facilities in Michigan and Minnesota. Thus, this rule is not subject to
the requirements of sections 202 or 205 of UMRA.
    This rule is also not subject to the requirements of section 203 of
UMRA because it contains no regulatory requirements that might
significantly or uniquely affect small governments. This rule only
applies to seven facilities in Michigan and Minnesota.

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, as
specified in Executive Order 13132. This action addresses Michigan and
Minnesota's failure to submit SIPs by the applicable deadline that meet
the regional haze requirements under the Clean Air Act. Thus, Executive
Order 13132 does not apply to this action. Although section 6 of
Executive Order 13132 does not apply to this action, EPA did consult
with Michigan and Minnesota in developing this action.

F. Executive Order 13175

    Subject to Executive Order 13175 (65 FR 67249, November 9, 2000),
EPA may not issue a regulation that has Tribal implication, that
imposes substantial direct compliance costs, and that is not required
by statute, unless the Federal government provides the funds necessary
to pay the direct compliance costs incurred by Tribal governments, or
EPA consults with Tribal officials early in the process of developing
the proposed regulation and develops a Tribal summary impact statement.
    EPA has concluded that this action may have Tribal implications.
For example, although the FIP does not apply to sources in Indian
country, controls and emission reductions arising from the program may
affect Indian country or other Tribal interests. However, the
regulations arising under this action will neither impose substantial
direct compliance costs on Tribal governments, nor preempt Tribal law.
    EPA initiated consultation with Tribal officials early in the
process of developing this regulation to permit them to have meaningful
and timely input into its development. EPA sent an invitation to
consult to each Region 5 Tribe on August 15, 2012, along with a copy of
the proposed taconite FIP Federal Register notice. Conference calls
were held on the taconite FIP proposal on August 22, 2012 and September
12, 2012 to provide all Region 5 Tribes with more information on the
proposed rulemaking and an opportunity to ask questions of EPA
technical staff and request individual consultation if desired. Four
Region 5 Tribes participated in the August 22, 2012 call. Two Region 5
Tribes participated in the September 12, 2012 discussion. One Region 5
Tribe provided verbal testimony at the public hearing held on the
proposed taconite FIP rulemaking on August 29, 2012. One Region 5
Tribal Chair expressed appreciation for the discussions held with the
Tribes and gratitude for EPA's careful consideration of the regional
haze situation in northeast Minnesota.

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

    EPA interprets Executive Order 13045 (62 FR 19885, April 23, 1997)
as applying only to those regulatory actions that concern health or
safety risks, such that the analysis required under section 5-501 of
the executive order has the potential to influence the regulation. This
action is not subject to Executive Order 13045 because it implements
specific standards established by Congress in statutes. However, to the
extent this rule will limit emissions, the rule will have a beneficial
effect on children's health by reducing air pollution.

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

    This action is not subject to Executive Order 13211 (66 FR 28355,
May 22, 2001) because it is not a significant regulatory action under
Executive Order 12866.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (``NTTAA''), Public Law 104-113, 12(d) (15 U.S.C. 272 note)
directs EPA to use voluntary consensus standards in its regulatory
activities unless to do so would be inconsistent with applicable law or
otherwise impractical. Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
voluntary consensus standards bodies. NTTAA directs EPA to provide
Congress, through OMB, explanations when the Agency decides not to use
available and applicable voluntary consensus standards.
    This action does not involve technical standards. Today's action
does not require the public to perform activities conducive to the use
of voluntary consensus standards. Therefore, EPA did not consider the
use of any voluntary consensus standards.

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) establishes
federal executive policy on environmental justice. Its main provision
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 and low-income
populations in the United States.
    We have determined that this rule will not have disproportionately
high and adverse human health or environmental effects on minority or
low-income populations because it increases the level of environmental
protection for all affected populations without having any
disproportionately high and adverse human health or environmental
effects on any population, including any minority or low-income
population. This rule limits emissions from seven facilities.

K. Congressional Review Act

    The Congressional Review Act, 5 U.S.C 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. Section 804 exempts from section 801 the following types
of rules: (1) Rules of particular applicability; (2) rules relating to
agency management or personnel; and (3) rules of agency organization,
procedure, or practice that do not substantially affect the rights or
obligations of non-agency parties. 5 U.S.C. 804(3). EPA is not required
to submit a rule report regarding today's action under section 801
because this is a rule of particular applicability.

L. Judicial Review

    Under section 307(b)(1) of the Clean Air Act, petitions for
judicial review of this action must be filed in the United States Court
of Appeals for the appropriate circuit by April 8, 2013. Pursuant to
Clean Air Act section 307(d)(1)(B), this action is subject to the
requirements of Clean Air Act section 307(d) because it promulgates a
FIP under Clean Air Act section 110(c). Filing a petition for
reconsideration by the Administrator of this final rule does not affect
the finality of this action for the purposes of judicial review, nor
does it extend the time within which a petition for judicial review may
be filed, and shall not postpone the effectiveness of such rule or
action. This action may not be challenged later in proceedings to
enforce its requirements. See Clean Air Act section 307(b)(2).

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Nitrogen dioxide, Particulate
matter, Reporting and recordkeeping requirements, Sulfur oxides,
Volatile organic compounds.

    Dated: January 15, 2013.
Lisa P. Jackson,
Administrator.

    40 CFR part 52 is amended as follows:

PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

0
1. The authority citation for part 52 continues to read as follows:

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

Subpart X--Michigan

0
2. Section 52.1183 is amended by adding and reserving paragraph (j),
and adding paragraphs (k), (l), (m), and (n) to read as follows:

Sec.  52.1183  Visibility protection.

* * * * *
    (j) [Reserved]
    (k) Tilden Mining Company, or any subsequent owner/operator of the
Tilden Mining Company facility in Ishpeming, Michigan, shall meet the
following requirements:
    (1) NOX Emission Limits. An emission limit of 1.5 lbs
NOX/MMBtu, based on a 30-day rolling average, shall apply to
the indurating furnace, Grate Kiln Line 1 (EUKILN1), beginning 26
months from March 8, 2013. However, for any 30, or more, consecutive
days when only natural gas is used a limit of 1.2 lbs NOX/
MMBtu, based on a 30-day rolling average, shall apply.
    (2) SO2 Emission Limits. A fuel sulfur content limit of no greater
than 1.20 percent sulfur content by weight shall apply to fuel
combusted in Process Boiler 1 (EUBOILER1) and Process Boiler
2 (EUBOILER2) beginning 3 months from March 8, 2013. A fuel
sulfur content limit of no greater than 1.50 percent sulfur content by
weight shall apply to fuel combusted in the Line 1 Dryer (EUDRYER1)
beginning 3 months from March 8, 2013. The sampling and calculation
methodology for determining the sulfur content of fuel must be
described in the monitoring plan required at paragraph (n)(8)(x) of
this section.
    (3) The owner or operator of the facility must switch Grate Kiln
Line 1 (EUKILN1) to 100 percent natural gas beginning 1 year from March
8, 2013. For the purposes of CEMS requirements, the compliance date by
which the CEMS must be installed and operated for Tilden is one year
from March 8, 2013. Within 26 months of March 8, 2013, the owner or
operator must calculate and comply with an SO2 limit based
on one year of hourly CEMS emissions data reported in lbs
SO2/hr and submit such limit, calculations and CEMS data to
EPA. This limit shall be calculated in terms of lbs SO2/hr,
based on the following equations, with compliance to be determined on a
30-day rolling average.

m - (n + 1) * [alpha]

m = the rank of the ordered data point, when data is sorted smallest
to largest
n = number of data points
[alpha] = 0.95, to reflect the 95th percentile

    If m is a whole number, then the limit, UPL, shall be computed
as:

UPL = Xm,
Where:

xm - value of the mth data point in terms of lbs SO2/hr,
when the data is sorted smallest to largest

    If m is not a whole number, the limit shall be computed by linear

interpolation according to the following equation.
[GRAPHIC] [TIFF OMITTED] TR06FE13.003

Where:

mt = the integer portion of m, i.e., m truncated at zero decimal
places, and
md = the decimal portion of m

    (4) Starting 26 months from March 8, 2013, records shall be kept
for any day during which fuel oil is burned as fuel (either alone or
blended with other fuels) in Grate Kiln Line 1. These records must
include, at a minimum, the gallons of fuel oil burned per hour, the
sulfur content of the fuel oil, and the SO2 emissions in
pounds per hour.
    (5) Starting 26 months from March 8, 2013 for Grate Kiln Line 1,
the SO2 limit does not apply for any hour in which it is
documented that there is a natural gas curtailment, beyond Cliffs'
control, necessitating that the supply of natural gas to Tilden's Line
1 indurating furnace is restricted or eliminated. Records must be kept
of the cause of the curtailment and duration of such curtailment.
During such curtailment, the use of backup coal is restricted to coal
with no greater than 0.60 percent sulfur by weight.
    (l) Testing and monitoring. (1) The owner or operator shall
install, certify, calibrate, maintain and operate a Continuous
Emissions Monitoring System (CEMS) for NOX on Tilden Mining
Company unit EUKILN1. Compliance with the emission limits for
NOX shall be determined using data from the CEMS.
    (2) The owner or operator shall install, certify, calibrate,
maintain and operate a CEMS for SO2 on Tilden Mining Company
unit EUKILN1. Compliance with the emission standard selected for
SO2 shall be determined using data from the CEMS.
    (3) The owner or operator shall install, certify, calibrate,
maintain and operate one or more continuous diluent monitor(s)
(O2 or CO2) and continuous flow rate monitor(s)
on Tilden Mining Company unit EUKILN1 to allow conversion of the
NOX and SO2 concentrations to units of the
standard (lbs/MMBtu and lbs/hr, respectively) unless a demonstration is
made that a diluent monitor and continuous flow rate monitor are not
needed for the owner or operator to demonstrate compliance with
applicable emission limits in units of the standards.
    (4) For purposes of this section, all CEMS required by this section
must meet the requirements of paragraphs (l)(4)(i)-(xiv) of this
section.
    (i) All CEMS must be installed, certified, calibrated, maintained,
and operated in accordance with 40 CFR Part 60, Appendix B, Performance
Specification 2 (PS-2) and Appendix F, Procedure 1.
    (ii) All CEMS associated with monitoring NOX (including
the NOX monitor and necessary diluent and flow rate
monitors) must be installed and operational no later than the
compliance date for the emission limit identified at (k)(1). All CEMS
associated with monitoring SO2 must be installed and
operational no later than twelve months after March 8, 2013.
Verification of the CEMS operational status shall, as a minimum,
include completion of the manufacturer's written requirements or
recommendations for installation, operation, and calibration of the
devices.
    (iii) The owner or operator must conduct a performance evaluation
of each CEMS in accordance with 40 CFR Part 60, Appendix B, PS-2. The
performance evaluations must be completed no later than 60 days after
the respective CEMS installation.
    (iv) The owner or operator of each CEMS must conduct periodic
Quality Assurance, Quality Control (QA/QC) checks of each CEMS in
accordance with 40 CFR Part 60, Appendix F, Procedure 1. The first CEMS
accuracy test will be a relative accuracy test audit (RATA) and must be
completed no later than 60 days after the respective CEMS installation.
    (v) The owner or operator of each CEMS must furnish the Regional
Administrator two, or upon request, more copies of a written report of
the results of each performance evaluation and QA/QC check within 60
days of completion.
    (vi) The owner or operator of each CEMS must check, record, and
quantify the zero and span calibration drifts at least once daily
(every 24 hours) in accordance with 40 CFR Part 60, Appendix F,
Procedure 1, Section 4.
    (vii) Except for CEMS breakdowns, repairs, calibration checks, and
zero and span adjustments, all CEMS required by this section shall be
in continuous operation during all periods of process operation of the
indurating furnaces, including periods of process unit startup,
shutdown, and malfunction.
    (viii) All CEMS required by this section must meet the minimum data
requirements at paragraphs (l)(4)(viii)(A)-(C) of this section.
    (A) Complete a minimum of one cycle of operation (sampling,
analyzing, and data recording) for each successive 15-minute quadrant
of an hour.
    (B) Sample, analyze and record emissions data for all periods of
process operation except as described in paragraph (l)(4)(viii)(C) of
this section.
    (C) When emission data from CEMS are not available due to
continuous monitoring system breakdowns, repairs, calibration checks,
or zero and span adjustments, emission data must be obtained using
other monitoring systems or emission estimation methods approved by the
EPA. The other monitoring systems or emission estimation methods to be
used must be incorporated into the monitoring plan required by this
section and provide information such that emissions data are available
for a minimum of 18 hours in each 24 hour period and at least 22 out of
30 successive unit operating days.
    (ix) Owners or operators of each CEMS required by this section must
reduce all data to 1-hour averages. Hourly averages shall be computed
using all valid data obtained within the hour but no less than one data
point in each fifteen-minute quadrant of an hour. Notwithstanding this
requirement, an hourly average may be computed from at least two data
points separated by a minimum of 15 minutes (where the unit operates
for more than one quadrant in an hour) if data are unavailable as a
result of performance of calibration, quality assurance, preventive
maintenance activities, or backups of data from data acquisition and
handling systems, and recertification events.
    (x) The 30-day rolling average emission rate determined from data
derived from the CEMS required by this section (in lbs/MMBtu or lbs/hr
depending on the emission standard selected) must be calculated in
accordance with paragraphs (l)(4)(x)(A)-(F) of this section.
    (A) Sum the total pounds of the pollutant in question emitted from
the Unit during an operating day and the previous twenty-nine operating
days.
    (B) Sum the total heat input to the unit (in MMBtu) or the total
actual hours of operation (in hours) during an

operating day and the previous twenty-nine operating days.
    (C) Divide the total number of pounds of the pollutant in question
emitted during the thirty operating days by the total heat input (or
actual hours of operation depending on the emission limit selected)
during the thirty operating days.
    (D) For purposes of this calculation, an operating day is any day
during which fuel is combusted in the BART affected Unit regardless of
whether pellets are produced. Actual hours of operation are the total
hours a unit is firing fuel regardless of whether a complete 24-hour
operational cycle occurs (i.e. if the furnace is firing fuel for only 5
hours during a 24-hour period, then the actual operating hours for that
day are 5. Similarly, total number of pounds of the pollutant in
question for that day is determined only from the CEMS data for the
five hours during which fuel is combusted.)
    (E) If the owner or operator of the CEMS required by this section
uses an alternative method to determine 30-day rolling averages, that
method must be described in detail in the monitoring plan required by
this section. The alternative method will only be applicable if the
final monitoring plan and the alternative method are approved by EPA.
    (F) A new 30-day rolling average emission rate must be calculated
for the period ending each new operating day.
    (xi) The 30-day rolling average removal efficiency determined from
data derived from the CEMS required by this section must be calculated
in accordance with paragraphs (l)(4)(xi)(A)-(G) of this section.
    (A) Calculate the 30-day rolling average emission rate described in
paragraphs (l)(4)(x)(A)-(F) of this section at the inlet of the control
device.
    (B) Calculate the 30-day rolling average emission rate described in
paragraphs (l)(4)(x)(A)-(F) of this section at the outlet of the
control device.
    (C) Subtract the 30-day rolling average emission rate determined at
the outlet of the control device from the 30-day rolling average
emission rate determined at the inlet of the control device.
    (D) Divide the result of paragraph (l)(4)(xi)(C) of this section by
the 30-day rolling average emission rate determined at the inlet.
    (E) Multiply the result of paragraph (l)(4)(xi)(D) of this section
by 100 to determine the 3-day rolling average percent removal
efficiency.
    (F) If the owner or operator of the CEMS required by this section
uses an alternative method to determine the 30-day rolling average
removal efficiency, that method must be described in detail in the
monitoring plan required by this section. The alternative method will
only be applicable if the final monitoring plan and the alternative
method are approved by EPA.
    (G) A new 30-day rolling average removal efficiency must be
calculated for each new operating day.
    (xii) Data substitution must not be used for purposes of
determining compliance under this section.
    (xiii) All CEMS data shall be reduced and reported in units of the
applicable standard.
    (xiv) A Quality Control Program must be developed and implemented
for all CEMS required by this section in accordance with 40 CFR Part
60, Appendix F, Procedure 1, Section 3. The program will include, at a
minimum, written procedures and operations for calibration checks,
calibration drift adjustments, preventative maintenance, data
collection, recording and reporting, accuracy audits/procedures,
periodic performance evaluations, and a corrective action program for
malfunctioning CEMS.
    (m) Recordkeeping requirements. (1)(i) Records required by this
section must be kept in a form suitable and readily available for
expeditious review.
    (ii) Records required by this section must be kept for a minimum of
5 years following the date of creation.
    (iii) Records must be kept on site for at least 2 years following
the date of creation and may be kept offsite, but readily accessible,
for the remaining 3 years.
    (2) The owner or operator of the BART affected unit must maintain
the records identified in paragraphs (m)(2)(i)-(xi) of this section.
    (i) A copy of each notification and report developed for and
submitted to comply with this section including all documentation
supporting any initial notification or notification of compliance
status submitted, according to the requirements of this section.
    (ii) Records of the occurrence and duration of each startup,
shutdown, and malfunction of the BART affected unit, air pollution
control equipment, and CEMS required by this section.
    (iii) Records of activities taken during each startup, shutdown,
and malfunction of the BART affected unit, air pollution control
equipment, and CEMS required by this section.
    (iv) Records of the occurrence and duration of all major
maintenance conducted on the BART affected unit, air pollution control
equipment, and CEMS required by this section.
    (v) Records of each excess emission report, including all
documentation supporting the reports, dates and times when excess
emissions occurred, investigations into the causes of excess emissions,
actions taken to minimize or eliminate the excess emissions, and
preventative measures to avoid the cause of excess emissions from
occurring again.
    (vi) Records of all CEMS data including, as a minimum, the date,
location, and time of sampling or measurement, parameters sampled or
measured, and results.
    (vii) All records associated with quality assurance and quality
control activities on each CEMS as well as other records required by 40
CFR Part 60, Appendix F, Procedure 1 including, but not limited to, the
quality control program, audit results, and reports submitted as
required by this section.
    (viii) Records of the NOX emissions during all periods
of BART affected unit operation, including startup, shutdown and
malfunction, in the units of the standard. The owner or operator shall
convert the monitored data into the appropriate unit of the emission
limitation using appropriate conversion factors and F-factors. F-
factors used for purposes of this section shall be documented in the
monitoring plan and developed in accordance with 40 CFR Part 60,
Appendix A, Method 19. The owner or operator may use an alternate
method to calculate the NOX emissions upon written approval
from EPA.
    (ix) Records of the SO2 emissions or records of the
removal efficiency (based on CEMS data), depending on the emission
standard selected, during all periods of operation, including periods
of startup, shutdown and malfunction, in the units of the standard.
    (x) Records associated with the CEMS unit including type of CEMS,
CEMS model number, CEMS serial number, and initial certification of
each CEMS conducted in accordance with 40 CFR Part 60, Appendix B,
Performance Specification 2 must be kept for the life of the CEMS unit.
    (xi) Records of all periods of fuel oil usage as required at
paragraph (k)(4) of this section.
    (n) Reporting requirements. (1) All requests, reports, submittals,
notifications, and other communications to the Regional Administrator
required by this section shall be submitted, unless instructed
otherwise, to the Air and Radiation Division, U.S. Environmental
Protection Agency, Region 5 (A-18J) at 77 West Jackson Boulevard,
Chicago, Illinois 60604.

References in this section to the Regional Administrator shall mean the
EPA Regional Administrator for Region 5.
    (2) The owner or operator of each BART affected unit identified in
this section and CEMS required by this section must provide to the
Regional Administrator the written notifications, reports and plans
identified at paragraphs (n)(2)(i)-(viii) of this section. If
acceptable to both the Regional Administrator and the owner or operator
of each BART affected unit identified in this section and CEMS required
by this section the owner or operator may provide electronic
notifications, reports and plans.
    (i) A notification of the date construction of control devices and
installation of burners required by this section commences postmarked
no later than 30 days after the commencement date.
    (ii) A notification of the date the installation of each CEMS
required by this section commences postmarked no later than 30 days
after the commencement date.
    (iii) A notification of the date the construction of control
devices and installation of burners required by this section is
complete postmarked no later than 30 days after the completion date.
    (iv) A notification of the date the installation of each CEMS
required by this section is complete postmarked no later than 30 days
after the completion date.
    (v) A notification of the date control devices and burners
installed by this section startup postmarked no later than 30 days
after the startup date.
    (vi) A notification of the date CEMS required by this section
startup postmarked no later than 30 days after the startup date.
    (vii) A notification of the date upon which the initial CEMS
performance evaluations are planned. This notification must be
submitted at least 60 days before the performance evaluation is
scheduled to begin.
    (viii) A notification of initial compliance, signed by the
responsible official who shall certify its accuracy, attesting to
whether the source has complied with the requirements of this section,
including, but not limited to, applicable emission standards, control
device and burner installations, CEMS installation and certification.
This notification must be submitted before the close of business on the
60th calendar day following the completion of the compliance
demonstration and must include, at a minimum, the information at
paragraphs (n)(2)(viii)(A)-(F) of this section.
    (A) The methods used to determine compliance.
    (B) The results of any CEMS performance evaluations, and other
monitoring procedures or methods that were conducted.
    (C) The methods that will be used for determining continuing
compliance, including a description of monitoring and reporting
requirements and test methods.
    (D) The type and quantity of air pollutants emitted by the source,
reported in units of the standard.
    (E) A description of the air pollution control equipment and
burners installed as required by this section, for each emission point.
    (F) A statement by the owner or operator as to whether the source
has complied with the relevant standards and other requirements.
    (3) The owner or operator must develop and implement a written
startup, shutdown, and malfunction plan for NOX and
SO2. The plan must include, at a minimum, procedures for
operating and maintaining the source during periods of startup,
shutdown, and malfunction; and a program of corrective action for a
malfunctioning process and air pollution control and monitoring
equipment used to comply with the relevant standard. The plan must
ensure that, at all times, the owner or operator operates and maintains
each affected source, including associated air pollution control and
monitoring equipment, in a manner which satisfies the general duty to
minimize or eliminate emissions using good air pollution control
practices. The plan must ensure that owners or operators are prepared
to correct malfunctions as soon as practicable after their occurrence.
    (4) The written reports of the results of each performance
evaluation and QA/QC check in accordance with and as required by
paragraph (l)(4)(v) of this section.
    (5) Compliance Reports. The owner or operator of each BART affected
unit must submit semiannual compliance reports. The semiannual
compliance reports must be submitted in accordance with paragraphs
(n)(5)(i) through (iv) of this section, unless the Regional
Administrator has approved a different schedule.
    (i) The first compliance report must cover the period beginning on
the compliance date that is specified for the affected source through
June 30 or December 31, whichever date comes first after the compliance
date that is specified for the affected source.
    (ii) The first compliance report must be postmarked no later than
30 calendar days after the reporting period covered by that report
(July 30 or January 30), whichever comes first.
    (iii) Each subsequent compliance report must cover the semiannual
reporting period from January 1 through June 30 or the semiannual
reporting period from July 1 through December 31.
    (iv) Each subsequent compliance report must be postmarked no later
than 30 calendar days after the reporting period covered by that report
(July 30 or January 30).
    (6) Compliance report contents. Each compliance report must include
the information in paragraphs (n)(6)(i) through (vi) of this section.
    (i) Company name and address.
    (ii) Statement by a responsible official, with the official's name,
title, and signature, certifying the truth, accuracy, and completeness
of the content of the report.
    (iii) Date of report and beginning and ending dates of the
reporting period.
    (iv) Identification of the process unit, control devices, and CEMS
covered by the compliance report.
    (v) A record of each period of a startup, shutdown, or malfunction
during the reporting period and a description of the actions the owner
or operator took to minimize or eliminate emissions arising as a result
of the startup, shutdown or malfunction and whether those actions were
or were not consistent with the source's startup, shutdown, and
malfunction plan.
    (vi) A statement identifying whether there were or were not any
deviations from the requirements of this section during the reporting
period. If there were deviations from the requirements of this section
during the reporting period, then the compliance report must describe
in detail the deviations which occurred, the causes of the deviations,
actions taken to address the deviations, and procedures put in place to
avoid such deviations in the future. If there were no deviations from
the requirements of this section during the reporting period, then the
compliance report must include a statement that there were no
deviations. For purposes of this section, deviations include, but are
not limited to, emissions in excess of applicable emission standards
established by this section, failure to continuously operate an air
pollution control device in accordance with operating requirements
designed to assure compliance with emission standards, failure to
continuously operate CEMS required by this section, and failure to
maintain records or submit reports required by this section.

    (7) Each owner or operator of a CEMS required by this section must
submit quarterly excess emissions and monitoring system performance
reports to the Regional Administrator for each pollutant monitored for
each BART affected unit monitored. All reports must be postmarked by
the 30th day following the end of each three-month period of a calendar
year (January-March, April-June, July-September, October-December) and
must include, at a minimum, the requirements at paragraphs (n)(7)(i)-
(xv).
    (i) Company name and address.
    (ii) Identification and description of the process unit being
monitored.
    (iii) The dates covered by the reporting period.
    (iv) Total source operating hours for the reporting period.
    (v) Monitor manufacturer, monitor model number and monitor serial
number.
    (vi) Pollutant monitored.
    (vii) Emission limitation for the monitored pollutant.
    (viii) Date of latest CEMS certification or audit.
    (ix) A description of any changes in continuous monitoring systems,
processes, or controls since the last reporting period.
    (x) A table summarizing the total duration of excess emissions, as
defined at paragraphs (n)(7)(x)(A)-(B) of this section, for the
reporting period broken down by the cause of those excess emissions
(startup/shutdown, control equipment problems, process problems, other
known causes, unknown causes), and the total percent of excess
emissions (for all causes) for the reporting period calculated as
described at paragraph (n)(7)(x)(C) of this section.
    (A) For purposes of this section, an excess emission is defined as
any 30-day rolling average period, including periods of startup,
shutdown and malfunction, during which the 30-day rolling average
emissions of either regulated pollutant (SO2 and
NOX), as measured by a CEMS, exceeds the applicable emission
standards in this section.
    (B) For purposes of this section, if a facility calculates a 30-day
rolling average emission rate in accordance with this section which
exceeds the applicable emission standards of this section, then it will
be considered 30 days of excess emissions. If the following 30-day
rolling average emission rate is calculated and found to exceed the
applicable emission standards of this section as well, then it will add
one more day to the total days of excess emissions (i.e. 31 days).
Similarly, if an excess emission is calculated for a 30-day rolling
average period and no additional excess emissions are calculated until
15 days after the first, then that new excess emission will add 15 days
to the total days of excess emissions (i.e. 30 + 15 = 45). For purposes
of this section, if an excess emission is calculated for any period of
time within a reporting period, there will be no fewer than 30 days of
excess emissions but there should be no more than 121 days of excess
emissions for a reporting period.
    (C) For purposes of this section, the total percent of excess
emissions will be determined by summing all periods of excess emissions
(in days) for the reporting period, dividing that number by the total
BART affected unit operating days for the reporting period, and then
multiplying by 100 to get the total percent of excess emissions for the
reporting period. An operating day, as defined previously, is any day
during which fuel is fired in the BART affected unit for any period of
time. Because of the possible overlap of 30-day rolling average excess
emissions across quarters, there are some situations where the total
percent of excess emissions could exceed 100 percent. This extreme
situation would only result from serious excess emissions problems
where excess emissions occur for nearly every day during a reporting
period.
    (xi) A table summarizing the total duration of monitor downtime, as
defined at paragraph (n)(7)(xi)(A) of this section, for the reporting
period broken down by the cause of the monitor downtime (monitor
equipment malfunctions, non-monitor equipment malfunctions, quality
assurance calibration, other known causes, unknown causes), and the
total percent of monitor downtime (for all causes) for the reporting
period calculated as described at paragraph (n)(7)(xi)(B) of this
section.
    (A) For purposes of this section, monitor downtime is defined as
any period of time (in hours) during which the required monitoring
system was not measuring emissions from the BART affected unit. This
includes any period of CEMS QA/QC, daily zero and span checks, and
similar activities.
    (B) For purposes of this section, the total percent of monitor
downtime will be determined by summing all periods of monitor downtime
(in hours) for the reporting period, dividing that number by the total
number of BART affected unit operating hours for the reporting period,
and then multiplying by 100 to get the total percent of excess
emissions for the reporting period.
    (xii) A table which identifies each period of excess emissions for
the reporting period and includes, at a minimum, the information in
paragraphs (n)(7)(xii)(A)-(F) of this section.
    (A) The date of each excess emission.
    (B) The beginning and end time of each excess emission.
    (C) The pollutant for which an excess emission occurred.
    (D) The magnitude of the excess emission.
    (E) The cause of the excess emission.
    (F) The corrective action taken or preventative measures adopted to
minimize or eliminate the excess emissions and prevent such excess
emission from occurring again.
    (xiii) A table which identifies each period of monitor downtime for
the reporting period and includes, at a minimum, the information in
paragraphs (n)(7)(xiii)(A)-(D) of this section.
    (A) The date of each period of monitor downtime.
    (B) The beginning and end time of each period of monitor downtime.
    (C) The cause of the period of monitor downtime.
    (D) The corrective action taken or preventative measures adopted
for system repairs or adjustments to minimize or eliminate monitor
downtime and prevent such downtime from occurring again.
    (xiv) If there were no periods of excess emissions during the
reporting period, then the excess emission report must include a
statement which says there were no periods of excess emissions during
this reporting period.
    (xv) If there were no periods of monitor downtime, except for daily
zero and span checks, during the reporting period, then the excess
emission report must include a statement which says there were no
periods of monitor downtime during this reporting period except for the
daily zero and span checks.
    (8) The owner or operator of each CEMS required by this section
must develop and submit for review and approval by the Regional
Administrator a site specific monitoring plan. The purpose of this
monitoring plan is to establish procedures and practices which will be
implemented by the owner or operator in its effort to comply with the
monitoring, recordkeeping and reporting requirements of this section.
The monitoring plan must include, at a minimum, the information at
paragraphs (n)(8)(i)-(x) of this section.
    (i) Site specific information including the company name, address,
and contact information.

    (ii) The objectives of the monitoring program implemented and
information describing how those objectives will be met.
    (iii) Information on any emission factors used in conjunction with
the CEMS required by this section to calculate emission rates and a
description of how those emission factors were determined.
    (iv) A description of methods to be used to calculate emission
rates when CEMS data is not available due to downtime associated with
QA/QC events.
    (v) A description of the QA/QC program to be implemented by the
owner or operator of CEMS required by this section. This can be the QA/
QC program developed in accordance with 40 CFR Part 60, Appendix F,
Procedure 1, Section 3.
    (vi) A list of spare parts for CEMS maintained on site for system
maintenance and repairs.
    (vii) A description of the procedures to be used to calculate 30-
day rolling averages and an example calculation which shows the
algorithms used by the CEMS to calculate 30-day rolling averages.
    (viii) A sample of the document to be used for the quarterly excess
emission reports required by this section.
    (ix) A description of the procedures to be implemented to
investigate root causes of excess emissions and monitor downtime and
the proposed corrective actions to address potential root causes of
excess emissions and monitor downtime.
    (x) A description of the sampling and calculation methodology for
determining the percent sulfur by weight as a monthly block average for
coal used during that month.

Subpart Y--Minnesota

0
3. Section 52.1235 is added to read as follows:

Sec.  52.1235  Regional haze.

    (a) [Reserved]
    (b)(1) NOX emission limits. (i) United States Steel Corporation,
Keetac: An emission limit of 1.5 lbs NOX/MMBtu, based on a
30-day rolling average, shall apply to the Grate Kiln pelletizing
furnace (EU030), beginning 3 years from March 8, 2013. However, for any
30, or more, consecutive days when only natural gas is used a limit of
1.2 lbs NOX/MMBtu, based on a 30-day rolling average, shall
apply.
    (ii) Hibbing Taconite Company: An emission limit of 1.5 lbs
NOX/MMBtu, based on a 30-day rolling average, shall apply to
the Line 1 pelletizing furnace (EU020) beginning 26 months from March
8, 2013. An emission limit of 1.5 lbs NOX/MMBtu, based on a
30-day rolling average, shall apply to the Line 2 pelletizing furnace
(EU021) beginning 38 months from March 8, 2013. An emission limit of
1.5 lbs NOX/MMBtu, based on a 30-day rolling average, shall
apply to the Line 3 pelletizing furnace (EU022) beginning 50 months
from March 8, 2013. However, for any 30, or more, consecutive days when
only natural gas is used at any Hibbing Taconite pelletizing furnace, a
limit of 1.2 lbs NOX/MMBtu, based on a 30-day rolling
average, shall apply to that furnace.
    (iii) United States Steel Corporation, Minntac: An emission limit
of 1.5 lbs NOX/MMBtu, based on a 30-day rolling average,
shall apply to each of the five indurating furnaces (EU225, EU261,
EU282, EU315, and EU334). The owner or operator shall comply with this
NOX emission limit beginning 12 months from March 8, 2013
for the Line 6 indurating furnace (EU315); 24 months from March 8, 2013
for the Line 7 indurating furnace (EU334); 36 months from March 8, 2013
for the Line 4 or Line 5 indurating furnace (EU261) or (EU282); 48
months from March 8, 2013 for the Line 5 or Line 4 indurating furnace
(EU282) or (EU261); and 59 months from March 8, 2013 for the Line 3
indurating furnace (EU225). However, for any 30 or more consecutive
days when only natural gas is used at any of Minntac's indurating
furnaces, a limit of 1.2 lbs NOX/MMBtu, based on a 30-day
rolling average, shall apply to that furnace.
    (iv) United Taconite: An emission limit of 1.5 lbs NOX/
MMBtu, based on a 30-day rolling average, shall apply to the Line 1
pellet furnace (EU040) beginning 38 months from March 8, 2013. An
emission limit of 1.5 lbs NOX/MMBtu, based on a 30-day
rolling average, shall apply to the Line 2 pellet furnace (EU042)
beginning 26 months from March 8, 2013. However, for any 30, or more,
consecutive days when only natural gas is used at either of United
Taconites' Line 1 or Line 2 pellet furnaces, a limit of 1.2 lbs
NOX/MMBtu, based on a 30-day rolling average, shall apply to
that furnace.
    (v) ArcelorMittal Minorca Mine: An emission limit of 1.5 lbs
NOX/MMBtu, based on a 30-day rolling average, shall apply to
the indurating furnace (EU026) beginning 26 months from March 8, 2013.
However, for any 30, or more, consecutive days when only natural gas is
used, a limit of 1.2 lbs NOX/MMBtu, based on a 30-day
rolling average, shall apply.
    (vi) Northshore Mining Company- Silver Bay: An emission limit of
1.5 lbs NOX/MMBtu, based on a 30-day rolling average, shall
apply to Furnace 11 (EU100/EU104) beginning 26 months from March 8,
2013. An emission limit of 1.5 lbs NOX/MMBtu, based on a 30-
day rolling average, shall apply to Furnace 12 (EU110/114) beginning 38
months from March 8, 2013. However, for any 30, or more, consecutive
days when only natural gas is used at either Northshore Mining Furnace
11 or Furnace 12, a limit of 1.2 lbs NOX/MMBtu, based on a
30-day rolling average, shall apply. An emission limit of 0.085 lbs/
MMBtu, based on a 30-day rolling average, shall apply to Process Boiler
1 (EU003) and Process Boiler 2 (EU004) beginning 5
years from March 8, 2013. The 0.085 lbs/MMBtu emission limit for each
process boiler applies at all times a unit is operating, including
periods of start-up, shut-down and malfunction.
    (2) SO2 emission limits. (i) United States Steel
Corporation, Keetac: An emission limit of 225 lbs SO2/hr,
based on a 30-day rolling average, shall apply to the Grate Kiln
pelletizing furnace (EU030). Any coal burned at Keetac shall have a
sulfur content of 0.60 percent sulfur by weight or less based on a
monthly block average. The sampling and calculation methodology for
determining the sulfur content of fuel must be described in the
monitoring plan required at paragraph (e)(8)(x) of this section.
Compliance with these requirements for EU030 is required beginning 3
months from March 8, 2013.
    (ii) Hibbing Taconite Company: An aggregate emission limit of 247.8
lbs SO2/hr shall apply to the three affected lines, EU020,
EU021, and EU022. The SO2 emission limits for these three
pelletizing furnaces are based on a 30-day rolling average. Emissions
resulting from the combustion of fuel oil are not included in the
calculation of the 30-day rolling average. However, if any fuel oil is
burned after the first day that SO2 CEMS are required to be
operational, then the information specified in (b)(2)(vii) must be
submitted, for each calendar year, to the Regional Administrator no
later than 30 days after the end of each calendar year so that a limit
can be set. Compliance with the emission limits is required beginning 6
months from March 8, 2013. Within 20 months of March 8, 2013, the owner
or operator may calculate a revised SO2 limit based on one
year of hourly CEMS emissions data reported in lbs SO2/hr
and submit such limit, calculations and CEMS data to EPA. This limit
shall be set in terms of lbs

SO2/hr, based on the following equations, with compliance to
be determined on a 30-day rolling average.

m=(n+1)*[alpha]

m = the rank of the ordered data point, when data is sorted smallest
to largest
n=[alpha] number of data points
[alpha] = 0.95, to reflect the 95\th\ percentile

    If m is a whole number, then the limit, UPL, shall be computed
as:

UPL = Xm,

Where:

X=m value of the m\th\ data point in terms of lbs
SO2/hr, when the data is sorted smallest to largest.

    If m is not a whole number, the limit shall be computed by linear
interpolation according to the following equation.
[GRAPHIC] [TIFF OMITTED] TR06FE13.004

Where:

m=[igr] the integer portion of m, i.e., m truncated at
zero decimal places, and
m=d the decimal portion of m

    (iii) United States Steel Corporation, Minntac: An aggregate
emission limit for indurating furnace Lines 3-7 (EU225, EU261, EU282,
EU315, and EU334) of 498 lbs SO2/hr shall apply when all
lines are producing flux pellets. An aggregate emission limit of 630
lbs SO2/hr shall apply to Lines 3-7 when Line 3-5 are
producing acid pellets and Lines 6 and 7 are producing flux pellets. An
aggregate emission limit of 800 lbs SO2/hr shall apply to
Lines 3-7 when all lines are producing acid pellets. The SO2
emission limits are based on a 30-day rolling average and apply
beginning 3 months from March 8, 2013. The emission limit for a given
30-day rolling average period is calculated using a weighted average as
follows:
[GRAPHIC] [TIFF OMITTED] TR06FE13.005

Where:

L30 = the limit for a given 30 day averaging period
nf = the number of days in the 30 day period that the facility is
producing flux pellets on lines 3-7
naf = the number of days in the 30 day period that the facility is
producing acid pellets on lines 3-5 and flux pellets on lines 6 and
7
na = the number of days in the 30 day period that the facility is
producing acid pellets on lines 3-7

    Also, beginning 3 months from March 8, 2013, any coal burned at
Minntac's Lines 3-7 shall have a sulfur content of 0.60 percent sulfur
by weight or less based on a monthly block average. The sampling and
calculation methodology for determining the sulfur content of fuel must
be described in the monitoring plan required at paragraph (e)(8)(x) of
this section.
    (iv) United Taconite: An aggregate emission limit of 529.0 lbs
SO2/hr, based on a 30-day rolling average, shall apply to
the Line 1 pellet furnace (EU040) and Line 2 pellet furnace (EU042)
beginning 54 months from March 8, 2013. Also, beginning 54 months from
March 8, 2013, any coal burned in the Line 1 or Line 2 pellet furnace
shall have a sulfur content of 0.60 percent sulfur by weight or less
based on a monthly block average. The sampling and calculation
methodology for determining the sulfur content of fuel must be
described in the monitoring plan required at paragraph (e)(8)(x) of
this section.
    (v) ArcelorMittal Minorca Mine: An emission limit of 38.16 lbs
SO2/hr, based on a 30-day rolling average, shall apply to
the indurating furnace (EU026) beginning 6 months from March 8, 2013.
This limit shall not apply when the unit is combusting fuel oil.
However, if any fuel oil is burned after the first day that
SO2 CEMS are required to be operational, then the
information specified in paragraph (b)(2)(vii) of this section must be
submitted, for each calendar year, to the Regional Administrator no
later than 30 days after the end of each calendar year so that a limit
can be set. Within 20 months of March 8, 2013, the owner or operator
may calculate a revised SO2 limit based on one year of
hourly CEMS emissions data reported in lbs SO2/hr and submit
such limit, calculations, and CEMS data to EPA. This limit shall be set
in terms of lbs SO2/hr, based on the following equations,
with compliance to be determined on a 30-day rolling average.

m = (n + 1) * [alpha]

m = the rank of the ordered data point, when data is sorted smallest
to largest
n = number of data points
[alpha] = 0.95, to reflect the 95\th\ percentile

    If m is a whole number, then the limit, UPL, shall be computed
as:

UPL = Xm,

Where:

xm = value of the mth data point in terms of lbs
SO2/hr, when the data is sorted smallest to largest

    If m is not a whole number, the limit shall be computed by linear
interpolation according to the following equation.
[GRAPHIC] [TIFF OMITTED] TR06FE13.006

Where:

mi = the integer portion of m, i.e., m truncated at zero decimal
places, and
m[alpha] = the decimal portion of m

    (vi) Northshore Mining Company--Silver Bay: An aggregate emission
limit of 39.0 lbs SO2/hr, based on a 30-day rolling average,
shall apply to Furnace 11 (EU100/EU104) and Furnace 12 (EU110/EU114).
Compliance with this limit is required within 6 months. Emissions
resulting from the combustion of fuel oil are not included in the
calculation of the 30-day rolling average. However, if any fuel oil is
burned after the first day that SO2 CEMS are required to be
operational, then the information specified in paragraph (b)(2)(vii) of
this section must be submitted, for each calendar year, to the Regional
Administrator no later than 30 days after the end of each calendar year
so that a limit can be set. Within 20 months of March 8, 2013, the
owner or operator must calculate a revised SO2 limit based
on one year of hourly CEMS emissions data reported in lbs
SO2/hr and submit such limit, calculations and CEMS data to
EPA. This limit shall be set in terms of lbs SO2/hr, based
on the following equations, with compliance to be determined on a 30-
day rolling average.

m = (n + 1) * [alpha]

m = the rank of the ordered data point, when data is sorted smallest
to largest
n = number of data points
[alpha] = 0.95, to reflect the 95th percentile

    If m is a whole number, then the limit, UPL, shall be computed
as:

UPL = Xm,

Where:

xm = value of the mth data point in terms of lbs
SO2/hr, when the data is sorted smallest to largest

    If m is not a whole number, the limit shall be computed by linear
interpolation according to the following equation.
[GRAPHIC] [TIFF OMITTED] TR06FE13.007

Where:

mi = the integer portion of m, i.e., m truncated at zero decimal
places, and
m[alpha] = the decimal portion of m

    (vii) Starting with the first day that SO2 CEMS are
required to be operational, for the facilities listed in paragraphs
(b)(2)(i)-(b)(2)(vi) of this section, records shall be kept for any day
during which fuel oil is burned (either alone or blended with other
fuels) in one or more of a facility's indurating furnaces. These
records must include, at a minimum, the gallons of fuel oil burned per
hour, the sulfur content of the fuel oil, and the SO2
emissions in pounds per hour. If any fuel oil is burned after the first
day that SO2 CEMS are required to be operational, then the
records must be submitted, for each calendar year, to the Regional
Administrator no later than 30 days after the end of each calendar
year.
    (c) Testing and monitoring. (1) The owner or operator of the
respective facility shall install, certify, calibrate, maintain and
operate Continuous Emissions Monitoring Systems (CEMS) for
NOX on United States Steel Corporation, Keetac unit EU030;
Hibbing Taconite Company units EU020, EU021, and EU022; United States
Steel Corporation, Minntac units EU225, EU261, EU282, EU315, and EU334;
United Taconite units EU040 and EU042; ArcelorMittal Minorca Mine unit
EU026; and Northshore Mining Company--Silver Bay units Furnace 11
(EU100/EU104) and Furnace 12 (EU110/EU114). Compliance with the
emission limits for NOX shall be determined using data from
the CEMS.
    (2) The owner or operator shall install, certify, calibrate,
maintain and operate CEMS for SO2 on United States Steel
Corporation, Keetac unit EU030; Hibbing Taconite Company units EU020,
EU021, and EU022; United States Steel Corporation, Minntac units EU225,
EU261, EU282, EU315, and EU334; United Taconite units EU040 and EU042;
ArcelorMittal Minorca Mine unit EU026; and Northshore Mining Company--
Silver Bay units Furnace 11 (EU100/EU104) and Furnace 12 (EU110/EU114).
    (3) The owner or operator shall install, certify, calibrate,
maintain and operate one or more continuous diluent monitor(s)
(O2 or CO2) and continuous flow rate monitor(s)
on the BART affected units to allow conversion of the NOX
and SO2 concentrations to units of the standard (lbs/MMBtu
and lbs/hr, respectively) unless a demonstration is made that a diluent
monitor and continuous flow rate monitor are not needed for the owner