assessments show the EPA recognizes the need to use multipliers in
assessing health risks from short-term emissions. The commenter stated
that it is unlawful and arbitrary for the EPA not to use an emissions
multiplier for estimating risk for this rulemaking.
---------------------------------------------------------------------------

    \98\ See, e.g., National Emission Standards for Hazardous Air
Pollutant Emissions: Group IV Polymers and Resins; Pesticide
Ingredient Production; and Polyether Polyols Production; Proposed
Rule, 77 FR 1268, 1279 (Jan. 9, 2012) (finalized at 79 FR 17340
(Mar. 27, 2014); see also National Emission Standards for Hazardous
Air Pollutants: Ferroalloys Production, 79 FR 60238, 60252 (Oct. 6,
2014) (applying ``an emission adjustment factor'' to ``average
annual hourly emission rates . . . to account for emission
fluctuations due to normal facility operations''); National
Emissions Standards for Hazardous Air Pollutants Residual Risk and
Technology Review for Flexible Polyurethane Foam Production, 78 FR
66108, 66122 (Nov. 4, 2013) (applying ``a conservative default
emissions multiplier of 10 to estimate the peak hourly emission
rates from the average rates'' as part of EPA's screening of
``worst-case acute impacts''); National Emissions Standards for
Hazardous Air Pollutants: Mineral Wool Production and Wool
Fiberglass Manufacturing, 76 FR 72770, 72785 (Nov. 25, 2011)
(applying an ``emissions multiplier of 3 to estimate the peak hourly
emission rates from the average rates'').
---------------------------------------------------------------------------

    The commenter also stated that the EPA's calculation of 1-hour
emissions assumed plants are operating (and generating emissions) 24
hours per day, 365 days per year. The commenter noted that averaging
hourly emissions over the full calendar year produces lower hourly
emissions than if the EPA had used each plant's actual operating hours.
The EPA has information about each plant's operating hours and these
data show many units are not operating over the full calendar year. By
calculating the 1-hour emissions based on 8,760 operating hours, the
commenter asserted the EPA underestimated the risks of acute exposures
over shorter spans of time.
    The commenter stated that because the EPA used short-term emissions
that are neither conservative nor realistic, the EPA cannot conclude
the standard assures ``an ample margin of safety.'' The commenter
stated that in two other recent rulemakings, the EPA found information
on short-term HCl emissions was insufficient to allow the EPA to
evaluate ``whether a chronic health-based emission standard for HCl
would ensure that acute exposures will not pose any health concerns.''
(75 FR 32031; 76 FR 25050). In these rulemakings, the commenter stated,
the EPA did not proceed with risk-based standards due to the lack of
this information. The commenter stated that the EPA is incorrectly
proceeding with the proposed health-based standards without accounting
for or quantifying peak short-term emissions.
    Response: The use of an emissions multiplier to convert annual
emissions to peak 1-hour emissions (determination of peak emissions for
comparison with 1-hour health benchmarks) for acute (short-term) risk
calculations was not necessary for this analysis, because the HBEL
determined for the category is being promulgated as a mass of HCl-
equivalent emitted per hour. Similarly, plant hours of operation need
not be considered because the HBEL determined for the category is an
hourly limit. As noted in the preamble to the proposed rule for BSCP,
``To assure that no source emits more than the 250 tpy HCl-equivalent
limit in a single hour, we propose setting the emissions limit at the
hourly equivalent of 250 tpy (57 lb/hr of HCl-equivalent emissions)''
(79 FR 75644). Similarly, for clay ceramics manufacturing, ``to assure
that no source emits more than the 600 tpy HCl-equivalent limit in a
single hour, we propose setting the emissions limit at the hourly
equivalent of 600 tpy (140 lb/hr of HCl-equivalent emissions)'' (79 FR
75661).
    The EPA concludes the risk analysis and subsequent standard meet an
``ample margin of safety'' in accordance with the CAA. The proposed
HBEL for the entire source category is based on an emissions level
corresponding to a maximum noncancer HI of one at the highest impacted
facility. All other facilities would have a lower risk than the highest
risk facility. Further, as the standard is based on a 1-hour emission
limit, in determining chronic impacts, the analysis conservatively
assumes that each plant emits at the 1-hour HBEL for an entire year
(8,760 hours).
    Comment: One commenter disagreed with the EPA's evaluation of acute
health risks, stating that the approach is inadequate and does not
assure standards are based on a safe health threshold and include ``an
ample margin of safety.'' Specifically, the commenter expressed concern
that the proposed HBEL are based on the chronic dose-response
information and not on thresholds for acute health risks. The commenter
noted the EPA approximated exposures, used those estimates to develop
HQ values, and concluded ``there is low potential for acute risk'' when
the HQ values are less than or equal to one. If values above one were
identified, then the EPA examined additional information to determine
whether there was a potential for ``significant acute risks'' for those
living near the facility. The commenter noted that the EPA did not
explain why this method satisfies the CAA section 112(d)(4) requirement
that health-based standards be set at a level that ensures ``an amply
margin of safety'' for people living near the facility. The EPA's
evaluation is designed to determine whether any facilities pose
``significant acute risks''; however, the commenter stated that this is
not the statutory standard, and such a determination would not signify
that an ``ample margin of safety'' is included.
    The commenter stated that for HF, the EPA's evaluation identified
numerous plants at which there were potential acute health risks.
Specifically, the EPA found 23 BSCP facilities exceeded the HQ value
for HF, with nearly half of those facilities exceeding the value by
four- or five-fold. For the clay ceramics category, the EPA found that
eight facilities exceeded the HQ value for HF. The additional analysis
the EPA performed to determine whether these facilities posed
``significant acute risks'' did not rule out the possibility of such
``significant acute risks.'' For these facilities, the EPA focused its
analysis on maximum offsite HQ values; however, the commenter noted
that many of the maximum offsite HQ values exceed one, thereby
indicating the potential for ``significant acute risks'' remained. The
commenter asserted that the EPA provided no support for why values
above one means there is no potential for ``significant acute risks.''
    The commenter disagreed with the EPA's assertion that there is no
potential for ``significant acute risks'' because the risk assessment
assumes there is a person present at the location and time where the
maximum HQ value occurs and stated that relaxing conservative
assumptions about exposure in individual instances is arbitrary and
defeats the purpose of the evaluation. The EPA cannot pretend that the
person is not present and ignore the potential for harm. The EPA's
statement that a facility is not likely to emit only HF similarly
provides no assurance of safety. According to the commenter, the EPA
relaxed an assumption in the model because the model predicted an
outcome the EPA did not like. The

commenter stated the EPA provided no basis for its assertion that a
facility is unlikely to emit only HF or explain why a combination of HF
(for which the EPA found a potential for ``significant acute risks''),
HCl, and Cl2 emissions would not still pose ``significant
acute risks.''
    The commenter stated that the EPA's use of acute exposure guideline
levels (AEGLs) and emergency response planning guidelines (ERPGs) to
assess acute risks cannot assure that exposure presents ``no risk'' of
health effects at those concentrations. The AEGL and ERPG values were
created for emergency exposure scenarios. The commenter stated that
levels defined for ``once-in-a-lifetime, short-term exposures'' and
``emergency'' chemical releases or accidents are not appropriate for
measuring acute exposure risk. According to the SAB, indicated ``AEGL-2
and ERPG-2 values should never be used in residual risk assessments
because they represent levels that if exceeded could cause serious or
irreversible health effects.'' \99\
---------------------------------------------------------------------------

    \99\ Memorandum from Science Advisory Board re: Review of EPA's
Draft at 6.
---------------------------------------------------------------------------

    The commenter stated that because the AEGL and ERPG numbers would
underestimate risk to the maximum exposed individual, AEGL and ERPG
values do not indicate ``safe'' thresholds that protect health with
``an ample margin of safety.'' For these reasons, the commenter
contends AEGL and ERPG values should not be used to set CAA section
112(d)(4) standards.
    Response: The EPA disagrees with the commenter that the EPA's acute
assessment includes arbitrary decision-making and does not reflect an
ample margin of safety. The EPA is not required to regulate based
solely on the results of a conservative acute screening scenario which
assumes that a person will be present at a specific location and during
worst-case meteorological conditions. Rather, this initial screening
scenario is used as a starting point in the assessment of the potential
for acute effects.
    For HCl and Cl2, the acute REL values for the pollutants
are not estimated to be exceeded even when using the screening
scenario, and the acute REL for HF is estimated to be exceeded only by
a factor of two for seven facilities using the screening scenario. The
other cases of higher exceedances mentioned by the commenter are
situations where the locations of the exceedances are on facility
property and, therefore, not considered for public health. The acute
REL is defined by CalEPA as ``the concentration level at or below which
no adverse health effects are anticipated for a specified exposure
duration. RELs are based on the most sensitive, relevant, adverse
health effect reported in the medical and toxicological literature.
RELs are designed to protect the most sensitive individuals in the
population by the inclusion of uncertainty factors which are
incorporated to address data gaps and uncertainties.
    Regarding the use of AEGL and ERPG values, the EPA does not rely
exclusively upon these values for assessment of acute exposures.
Rather, the EPA's approach is to consider various acute health effect
reference values, including the California REL, in assessing the
potential for risks from acute exposures. To better characterize the
potential health risks associated with estimated acute exposures to
HAP, and in response to a key recommendation from the SAB's peer review
of the EPA's RTR risk assessment methodologies, we generally examine a
wider range of available acute health metrics (e.g., RELs, AEGLs) than
we do for our chronic risk assessments. This is in response to the
SAB's acknowledgement that there are generally more data gaps and
inconsistencies in acute reference values than there are in chronic
reference values. In some cases, when Reference Value Arrays \100\ for
HAP have been developed, we consider additional acute values (i.e.,
occupational and international values) to provide a more complete risk
characterization. Because HCl, HF, and Cl2 all have 1-hour
REL values, the maximum estimated 1-hour concentrations were compared
to these values to assess the potential for acute health effects.
---------------------------------------------------------------------------

    \100\ U.S. EPA. (2009) Chapter 2.9 Chemical Specific Reference
Values for Formaldehyde in Graphical Arrays of Chemical-Specific
Health Effect Reference Values for Inhalation Exposures (Final
Report). U.S. Environmental Protection Agency, Washington, DC, EPA/
600/R-09/061, and available on-line at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=211003.
---------------------------------------------------------------------------

    Comment: One commenter expressed concern that the EPA's risk
analysis ignored exposures from emissions of HCl, HF, Cl2,
and other pollutants with similar biological endpoints from units
subject to the proposed work practice standards, including emissions
during startup and shutdown, and emissions from BSCP periodic kilns and
sanitaryware shuttle kilns. The commenter asserted that even though the
EPA stated that the work practice standards are intended to minimize
emissions, these sources are not included in the calculation of the CAA
section 112(d)(4) standards, and exposures to emissions from these
other sources will contribute to an individual's cumulative health
risks. The commenter asserted that the EPA does not know whether the
proposed HBEL will provide ``an ample margin of safety'' once emissions
from periods of startup and shutdown and emissions from BSCP periodic
kilns and sanitaryware shuttle kilns are added to the levels of
pollution permitted by the proposed standards. For this reason, the
commenter stated that the proposed CAA section 112(d)(4) standards are
unlawful and arbitrary.
    The commenter also stated that emissions during startup and
shutdown are expected to be uncontrolled, because the EPA did not
propose to require that BSCP and clay ceramics plants use APCD or other
methods to reduce emissions (such as mandating the use of clean fuels)
during these periods. The proposed work practice standards for periodic
and shuttle kilns do not require control technology and, according to
the commenter, are not anticipated to reduce emissions.
    Finally, the commenter stated that the only reason startup and
shutdown periods and periodic and shuttle kilns are not subject to the
proposed CAA section 112(d)(4) limits is because the EPA exempted them
from CAA section 112(d). The commenter stated that it is arbitrary to
exclude those emissions from the health analysis solely because the EPA
proposed to regulate those sources of emissions under a different
subsection of the CAA. The commenter argued all exposures contribute to
the risk of harm, regardless of whether they are CAA section 112(d)-
regulated emissions or section CAA 112(h)-regulated emissions.
    Response: The EPA disagrees that emissions during periods of
startup and shutdown and emissions from BSCP periodic kilns and
sanitaryware shuttle kilns will exceed the numerical HBEL. Regarding
the standards for periods of startup and shutdown, as noted in the
preamble to the proposed rule and further documented in Docket ID No.
EPA-HQ-OAR-2013-0291,\101\ temperature is the main factor affecting
full production at BSCP plants. The kiln cars should be introduced into
the kiln at a steadily increasing push rate to facilitate development
of that specific kiln's firing temperature profile. Since emissions are
generated from the firing of the bricks and the fuel combusted, the EPA
has concluded that the maximum magnitude of emissions will occur when
all kiln cars have been

loaded with the maximum number of bricks and the maximum amount of fuel
is used. During startup, kiln operators will limit production until the
kiln has heated enough to begin normal operation. This is the point
whereby the standard transitions from a work practice to a numeric
limit. The opposite process occurs during shutdown. Fuel use will
decrease significantly so as to cool the kiln, and kiln operators will
slow production to a stop. Since emissions will be lower below this
point of maximum loading and fuel use, emissions will not rise above
the emission limit for all pollutants, including the acid gas limits.
---------------------------------------------------------------------------

    \101\ Email from Susan Miller, BIA, to Sharon Nizich and Keith
Barnett, EPA. ``Additional documents.'' Dated June 25, 2015.
---------------------------------------------------------------------------

    The owner or operator of each kiln will be required to determine
the startup production rate for the kiln. For kilns with an APCD, the
owner or operator will determine the minimum inlet temperature for the
APCD. For kilns that, through compliance testing once the compliance
date has been reached, have shown they are emitting under the emission
limits and thus do not have an APCD, the owner or operator will
determine the product-specific kiln temperature profile that must be
achieved before the kiln can reach full production. The startup
standards will be tied to the startup production rate never being
exceeded until the kiln reaches the minimum inlet temperature for the
APCD or the product-specific kiln temperature profile, whichever is
applicable. During shutdown, once the kiln falls below the minimum
inlet temperature for the APCD or the product-specific kiln temperature
profile, whichever is applicable, no additional product can be
introduced. These temperature limits will be required to be included in
the facility's records and kept on site. Thus, for periods of startup
and shutdown, the HBEL set for HCl, HF, and Cl2 will not be
surpassed during startup and shutdown.
    In the case of sanitaryware shuttle kilns, the commenter is
mistaken that we did not mandate the use of clean fuels. The rule does
limit the fuels used to natural gas or equivalent, and also outlines
work practice standards relative to temperature cycles and maintenance
procedures designed to minimize HAP emissions (see Table 3 to subpart
KKKKK). The use of clean fuels applies for all times the kiln is
running, not just startup and shutdown. Therefore, the commenter is
incorrect that we are not requiring the use of clean fuels for startup
and shutdown relative to the operation of shuttle kilns.
    The EPA also disagrees that just because the proposed work practice
standards for periodic and shuttle kilns do not reflect the use of any
control technology, they are not anticipated to reduce emissions. As
the commenter has stated elsewhere, control technologies are not the
only means of limiting emissions. Control of parameters such as fuel,
operating temperature, combustion conditions, and throughput are also
effective means of limiting emissions, and these are the types of
parameters the EPA considered when finalizing the work practice
standards for periodic and shuttle kilns.
    As discussed in the proposal at 79 FR 75662, CAA section 112(h)(1)
states that the Administrator may prescribe a work practice standard or
other requirements, consistent with the provisions of CAA sections
112(d) or (f), in those cases where, in the judgment of the
Administrator, it is not feasible to enforce an emission standard.
Section 112(h)(2)(B) of the CAA further defines the term ``not
feasible'' in this context to apply when ``the application of
measurement technology to a particular class of sources is not
practicable due to technological and economic limitations,'' which is
the case here. There are fewer BSCP periodic kilns and first-fire
sanitaryware shuttle kilns compared to tunnel kilns, and they tend to
be low-emitting sources compared to tunnel kilns,\102\ so their
emissions will not cause an exceedance of the health threshold. The
work practice standards we are finalizing will serve to ensure that
emissions from these sources continue to remain low.
---------------------------------------------------------------------------

    \102\ For example, even assuming that lb/ton emissions are
similar for BSCP periodic and tunnel kilns, a comparison of annual
kiln design capacities (ton product/yr) for model BSCP periodic
kilns and tunnel kilns indicates that annual capacities for periodic
kilns are on average only 5 percent of annual capacities for tunnel
kilns. (For the basis of this calculation, see the memorandum
``Updated Inventory Database and Documentation for Brick and
Structural Clay Products Manufacturing Final Rule'' in Docket ID No.
EPA-HQ-OAR-2013-0291 and the memorandum ``Final Rule: Documentation
of Database and Responses to the 1997 Information Collection Request
for Brick and Structural Clay Products'' in Docket ID No. A-99-30.)
In addition, in the BSCP industry, there are currently 120 periodic
kilns located at 15 facilities, compared to 168 tunnel kilns at 84
facilities. In the sanitaryware industry sector, there are currently
five first-fire shuttle kilns, compared to 11 first-fire tunnel
kilns.
---------------------------------------------------------------------------

    Comment: One commenter stated that, to create standards that assure
``an ample margin of safety,'' the EPA is required to build a margin
into the HBEL for exposures to HCl, HF, Cl2, and other
pollutants with similar biological endpoints resulting from (a)
exceedances of the HCl, HF, and Cl2 standards, (b)
violations of the work practice standards applicable during startup and
shutdown, and (c) exceedances of other standards (e.g., MACT standards
for non-Hg HAP metals) that restrict pollutants with similar biological
endpoints. The commenter also stated that estimating short-term
emissions by averaging annual emissions does not reflect emissions
spikes that occur during plant malfunctions or upsets. The commenter
stated that malfunctions and upsets increase emissions and thereby pose
increased health risks that the EPA must consider.
    The commenter stated that relevant chronic exposures include
exposures from exceedances and violations and noted that many
exceedances, such as those from malfunctions and upsets, are likely to
contribute significant emissions that can elevate an individual's total
exposures over time. The commenter also stated that the EPA explains
malfunction events can be significantly higher than emissions at any
other time of source operation (79 FR 75626). The commenter stated that
these emissions pose much higher short-term risks and can accumulate
and combine to increase public health impacts and risk and that
guarding against the health risks of releases of large amounts of HF
(for example) must be built into the HBEL through the margin of safety.
The commenter stated that HF exhibits characteristics in some
circumstances that can make it uniquely hazardous over large areas. For
example, HF molecules may associate with one another (i.e., form larger
molecules like H4F4, H6F6,
H8F8) via hydrogen bonding and such molecules may
form a cloud that is heavier than air, therefore less likely to
disperse.
    The commenter stated that, by not accounting for exposures from
exceedances, the EPA assumed that such exceedances will be zero and
built in no additional protections in case exceedances do occur. The
commenter claimed that there is no factual basis for assuming that 100
percent of BSCP and clay ceramics facilities will comply with each of
the relevant emissions limits 100 percent of the time. Over the long
term and across the population of regulated facilities, the commenter
noted that it is predictable that a number of exceedances will occur at
facilities. The commenter stated it is unlawful to ignore emissions and
the resulting health risks from those exceedances and argued the
additional risk from exceedances should not be ignored in risk
assessments.
    The commenter stated that EPA regularly uses statistical methods
and probability factors to assess health risk due to exceedances and to
set clean air standards, and the EPA has data available to calculate
representative factors to assess the health risk from

malfunctions or can collect information on major sources' malfunction
and violation histories.\103\ If the EPA needs more refined data
regarding these emissions, the commenter suggested the EPA may request
additional data from sources.
---------------------------------------------------------------------------

    \103\ See, e.g., EPA, Enforcement and Compliance History Online
(ECHO), www.epa.gov/echo.
---------------------------------------------------------------------------

    The commenter stated that it is irrelevant that exceedances are a
result of a failure to comply with the law when the EPA is setting CAA
section 112(d)(4) standards, which must be set at a level that protects
health. It does not matter to a person whether the pollution he or she
is breathing is a result of a permitted or unpermitted release; the
commenter argued the EPA cannot turn a blind eye to the reality that
compliance with its standards is not perfect.
    Response: The HBEL was determined based on the assessment of acute
affects at the worst-case facility with respect to meteorology and
distance to receptor and is protective of most facilities even if they
had SSM event emissions. Even for the worst-case facility, the SSM
emissions event would need to be coincident with the worst-case
meteorological conditions, which is not likely if SSM events are not
frequent. For chronic risk, SSM emissions are not significant compared
to the HBEL level, and most facilities are well below an HI of one with
emissions at the HBEL level.
    The commenter is correct that the EPA did not include malfunctions
and upsets emissions in setting emissions limits. As noted in the
preamble to the proposed rule (79 FR 75626), malfunctions ``are, by
definition sudden, infrequent and not reasonably preventable failures
of emissions control, process or monitoring equipment.'' The preamble
also stated that ``accounting for malfunctions in setting emission
standards would be difficult, if not impossible, given the myriad
different types of malfunctions that can occur across all sources in
the category and given the difficulties associated with predicting or
accounting for the frequency, degree and duration of various
malfunctions that might occur. For these reasons, the performance of
units that are malfunctioning is not `reasonably' foreseeable.'' It
should also be noted that sources cannot conduct performance tests
during periods of malfunction (40 CFR 63.8445(e) and 40 CFR 63.8595(d))
and there are no continuous emissions monitoring systems (CEMS) in
place in the BSCP industry.
    The EPA disagrees that it is required to evaluate the ample margin
of safety provided by a CAA section 112(d)(4) standard based on the
level of emissions that could occur during an exceedance of the
standard caused by a malfunction or any other cause. When the EPA
establishes a standard under CAA section 112(d)(4), the EPA evaluates
the ample margin of safety based on what sources will emit when they
are meeting the standard (which applies at all times including periods
of malfunction) and does not include some additional margin of safety
to compensate for periods of time that sources may violate the
standard. This is consistent with how the EPA evaluates standards under
CAA section 112(f)(2) (in that the EPA's evaluation of the ample margin
of safety under that review looks at the emissions allowed under the
standard, not emissions that might occur when the standard is
exceeded).
    Regarding the comment that the standard is not health protective
for emissions of HF, the proposed rule determined the HCl equivalent
emissions for HF by the ratio of the RfC value for each pollutant, such
that a 250 tpy emission of HCl is equivalent to 175 tpy emissions of
HF. By performing a risk analysis for each facility/kiln, the EPA
demonstrated that these emissions limits are protective of both chronic
and acute risks.
    Regarding the comment that HF exhibits release characteristics that
may make it uniquely hazardous over large areas, the EPA notes that the
commenter did not include data or information supporting their
assertion that plumes of acid gases from BSCP facilities could become
heavier than air. The commenter's example case of the formation of
dense clouds of acid gases is from studies performed on the
vaporization of liquefied gaseous fuels from spills, and the commenter
did not explain how this scenario is relevant to the emission of acid
gases formed in BSCP kilns. In the absence of evidence suggesting that
clouds of dense gases are formed from BSCP facilities, and without a
suggested alternate modeling methodology, the EPA used its preferred
model AERMOD for dispersion for BSCP facilities.
7. Other Issues
    Comment: One commenter stated that the EPA must account for the
variability in emissions measured by compliance testing to measure
whether each plant's emissions meet the HBEL because that testing does
not capture a source's variance in emissions performance over time. The
commenter noted that the EPA already recognizes this fact for stack
tests for technology-based standards. The EPA has stated that it lacks
a high degree of confidence that stack tests capture variation in
emissions over time, and the commenter noted that as a result of this
variance, it can be expected that the compliance tests would not be
accurate. The commenter asserted that if the EPA believes that
measurement variability needs to be corrected for, then it is
irrational and arbitrary to correct for it with one set of standards
(MACT standards) and not another (health-based standards), when they
both rely upon emissions data from stack tests. The commenter noted
that the EPA's proposal to account for variability for MACT standards
but not for compliance with the HBEL would result in weaker and less-
protective standards in both cases.
    Response: Variability in emissions would not have a significant
impact on the estimated risks associated with the HBEL. For chronic
exposures and risks, the estimates are based on long-term (annual)
emissions, so short-term emissions variability would not impact the
estimates of chronic risks as long as the annual emissions, on average,
do not exceed the limit. For acute exposures and risks, short-term
emissions variability that causes emissions to exceed the 1-hour HBEL
would increase the potential for acute health effects, but the
likelihood of such effects is low because the emissions variability
would have to occur at the small number of facilities we estimated as
having the highest acute HQs based on the emissions limits, and the
emissions variability would have to coincide with worst-case
meteorological conditions even at those facilities to result in acute
HQs higher than those we estimated based on the HBEL. Most facilities
have acute HQ estimates significantly below one, so short-term
emissions variability would have to be high (approximately 60 percent
higher for the median facility) for the estimated HQs to approach a
value of one.
    The EPA also notes that the HBEL was not established using
emissions data from stack tests. Therefore, there was no need to
account for variability in setting the HBEL as was done for the Hg and
non-Hg HAP metals standards. Instead, the standard was established at a
conservative level to ensure that the HQs remain below one for all
facilities. The EPA agrees that there would be variability in the test
results used to demonstrate compliance with the rule, but as already
noted in this response, short-term emissions variability would have to
be high for the estimated HQs to approach a value of one. In addition,

variability is not considered when comparing compliance testing results
to any other emissions limit, so it would be inconsistent for the EPA
to require owners and operators to adjust their test results before
comparing those results to the HBEL.
    Comment: One commenter suggested that the EPA should require fence-
line ambient air quality monitoring that measures multiple pollutants
in real-time or near real-time to ensure that people are not being
exposed to ambient pollutant concentrations that exceed the proposed
HBEL. The commenter recommended the EPA also require real-time public
reporting of the monitoring data.
    In addition, the commenter suggested that the EPA should require
facilities to submit monitoring plans, data, and corrective action
plans for agency review and public comment. These requirements would
ensure concerned community members have the ability to review and
recommend improvements to monitoring plans before they are implemented
and would enable the EPA to consider community concerns when deciding
whether to approve a plan.
    Response: The EPA disagrees with the commenter. Because stack
emissions can travel for long distances and are at heights above where
a fence-line monitors would measure, it is inappropriate to use fence-
line monitoring for stack emissions. Fence-line monitoring is performed
for fugitive emissions (see discussion of fence-line monitoring use on
fugitive emissions at 79 FR 36919, Petroleum Refinery Sector Risk and
Technology Review and New Source Performance Standards; Proposed Rule).
In response to the comment that the EPA should require all facilities
to submit monitoring plans, data, and corrective action plans for
agency review and public comment, the EPA notes that these requirements
are indeed in the rule, as facilities are required to submit monitoring
plans, data and corrective actions for the regulatory agency review.
However, in most cases, these submissions are required to be sent to
the delegated authority, and the follow-up to that review, is left to
the discretion of the delegated authority.

B. BSCP Manufacturing NESHAP

1. MACT Floors
a. Sources in MACT Floor Pool
    One commenter stated that the DC Circuit held that the BSCP
Manufacturing NESHAP published on May 16, 2003 (68 FR 26690) violated
the CAA in a number of ways (Sierra Club v. EPA, 479 F.3d 875 (D.C.
Cir. 2007)). The court held that, in setting MACT floors for brick
tunnel kilns, the EPA's exclusion of kilns employing non-DLA controls
from its ranking and identification of the best performing sources was
unlawful because CAA section 112(d)(3) ``requires floors based on the
emission level actually achieved by the best performers (those with the
lowest emission levels).'' Id. In addition, the court recognized that
factors other than pollution control technology affect performance
(e.g., clay type), and the EPA cannot ignore such factors, even where
the EPA finds that floors based on those factors would be unachievable.
    The commenter noted that the EPA is once again excluding best
performing sources from its floor analysis and basing floors on a group
of kilns using the EPA's preferred control technologies, in
contravention of the holding of Sierra Club, which is the decision to
which this rulemaking is intended to be a response. In the proposed
rule, prior to ranking the best performing sources for the BSCP tunnel
kiln floors for PM (as a surrogate for non-Hg HAP metals) for existing
and new sources, the EPA removed all kilns without a FF-based APCD.
Once removed, those kilns were not included in the ranking of best
performing sources, and hence they were not considered for inclusion
among the best performing 12 percent of sources (for the existing
source floor) or the best controlled similar source (for the new source
floor). The commenter asserted that the agency's reprisal of a floor
approach that the DC Circuit has already rejected repeatedly is not
just unlawful, but amounts to contempt for the court's authority.
    Response: The EPA disagrees with the commenter's assertion that the
EPA's proposed approach to calculating PM surrogate MACT floors for
kilns was illegal in that it impermissibly excluded certain kilns.
However, at proposal, we asked for comment on this approach and
requested additional data to support this approach, and we did not
receive any such additional data. In addition, some of the test data
for sources with FF-based APCD could not be used in the final
rulemaking because it was discovered that the testing was not carried
out in accordance with the appropriate test method. Therefore, we can
no longer assert that we have emissions data for all BSCP kilns with
FF-based APCD. Thus, the EPA did not use the approach challenged by the
commenter to establish the MACT floors in the final rule.
    The EPA has amended the approach to developing PM surrogate MACT
floors for reasons explained in section IV.A.1 of this preamble, so
these comments are now moot. However, the EPA still believes the
approach to identify the best performing sources has merit. When the
EPA has data on every single controlled source in the category, and
these data support that these sources are the best performing, then
basing the MACT floor on the top 12 percent of the total number of
sources is appropriate.
b. Equivalent Limits
    Comment: One commenter stated that, in addition to the lb/ton MACT
floors for emissions of Hg and PM (as a surrogate for non-Hg HAP
metals), the EPA developed two ``equivalent limits.'' The EPA used its
ranking of the sources based on their ``average'' lb/ton emissions to
identify the best performing source or sources for the floor pool. To
develop the PM and Hg ``equivalent'' limits, the EPA took the best
performing source or sources the EPA had selected and retrieved data on
those sources' emission performance as measured by gr/dscf at 7-percent
O2 for PM and Hg and lb/hr for Hg. For non-Hg HAP metals,
the EPA proposed to set an additional standard that would limit the
pounds of non-Hg HAP metals emitted per hour. For this additional
limit, the EPA again used the ranking of the sources based on their
``average'' lb/ton emissions and also (without any explanation) no
longer used PM as a surrogate for non-Hg HAP metals, but instead set
the limit in terms of total non-Hg HAP metals. The commenter stated
that the EPA acknowledged that the available data on non-Hg HAP metals
is incomplete, so to develop this proposed limit, the EPA simply took
the final pounds of PM per ton of fired product floor limit that it had
derived and applied a set of ``conversion factors'' it invented to put
that standard in terms of pounds of non-Hg HAP metal emissions per
hour. The commenter stated the EPA used completely different
``conversion'' methodologies for the new and existing standards because
the EPA lacks even the limited data it used for the existing source
methodology on new sources.
    The commenter stated the ``equivalent'' limits the EPA proposed are
not ``equivalent'' and Congress did not give the EPA the authority to
set multiple limits and allow sources to comply with whichever limit
they choose. The commenter stated the EPA's use of different measures
of performance to identify the top sources on the one hand and to
evaluate their performance on the other is inconsistent, irrational,
and unexplained; the same metric should

apply for purposes of identifying the best performers and identifying
those sources' actual performance. The commenter also stated the EPA
did not use the best performing 12 percent of existing sources ``for
which the Administrator has emissions information'' for the non-Hg HAP
metals lb/hr limit.
    Another commenter supported the EPA's inclusion of multiple formats
for both PM/non-Hg HAP metals and Hg. The commenter stated that the
inclusion of each of these formats, as well as the inclusion of small
and large kiln subcategories, provides needed flexibility to numerous
BSCP facilities, including a large number of small businesses, to find
that standard that best suits their operations while still ensuring
that the CAA requirements are met. The commenter asserted that the
inclusion of three alternate compliance formats is so critical to the
development of this standard that the EPA must re-propose this rule if
it maintains numeric limits but deletes any of these alternative
formats for the final rule.
    Response: The EPA appreciates all comments regarding the
alternative limits. The EPA is retaining the alternative limits in the
final rule but is revising the ranking methodology as described in
section IV.A.2 of this preamble. For the final rule, the concentration
floor is based on the ranking of the concentration data, and the lb/hr
floor is based on the ranking of the lb/hr data. Each floor is based on
the best performing units for that unit of measurement.
c. Oxygen Correction
    Comment: One commenter stated, regarding the concentration
compliance limits, that the use of the equation to correct measured
concentrations to 7-percent O2 could be problematic when
used to correct concentrations measured in stacks with high
O2 content, which is typical of the brick industry. The
commenter stated because the correction term is in the denominator of
the equation for the correction to 7-percent O2, the overall
correction factor increases exponentially as O2
concentrations approach 20.9 percent. As a result, any variances in the
O2 measurement are greatly magnified in the correction
factor for kilns with high stack O2 content. The commenter
suggested that the correction factor should be the average
O2 content represented in the respective floors, 17- percent
O2 (based on a range of O2 stack contents for
BSCP kilns from 13 to 20 percent). The commenter asserted that the
correction to an average of 17-percent will minimize the artificial
inflation of the results for the industry.
    Response: The EPA evaluated the O2 content of the run-
by-run datasets of PM and Hg for BSCP tunnel kilns as described in
section IV.A.1 of this preamble and agrees that correcting
concentration data to 17-percent O2 rather than 7-percent,
as proposed, provides more representative values of kilns' operating
conditions and would not artificially inflate the values. For the final
rule, the EPA has taken the O2 percent analysis into
consideration and revised the equivalent concentration based limits to
be developed from 17-percent O2-corrected concentration
data.
2. Startup and Shutdown
    Comment: Numerous commenters supported the use of work practice
standards for periods of startup and shutdown but asserted that the
startup and shutdown procedures listed in the proposed rule cannot be
met by all BSCP kilns and must be modified. Commenters requested that
the final language allow a more basic construct for the work practice
requirements in the final rule and require facilities to develop site-
specific temperatures as part of their permitting process.
    Multiple commenters specifically stated that the requirement for an
exhaust temperature of 400[emsp14][deg]F at startup is not workable
because the kiln exhaust temperature in some kilns never reaches
400[emsp14][deg]F. Commenters also noted that kilns must have product
at startup. Therefore, commenters requested that the startup provisions
apply to the introduction, or charging, of new brick or structural clay
product through a kiln and not impact the initial staging of kiln cars
in a kiln before start-up. Commenters suggested revisions to the
proposed language to ``not put any bricks into the kiln'' below
specified temperatures.
    Multiple commenters agreed with the language that requires a kiln
to vent to an APCD before the exhaust gas reaches 400[emsp14][deg]F,
because it can vent at any time up to that temperature. Multiple
commenters stated that for a controlled kiln, it is acceptable to
require that no new product is allowed to be introduced to the
controlled kiln until the kiln is vented to an APCD. One commenter
stated that a feasible work practice standard would be for the exhaust
gases to be vented through the APCD during the startup process, with
the reagent feed started on an intermittent basis during this period
and then brought up to full feed rate once the exhaust temperature has
reached the normal operating temperature range.
    A few commenters also requested specific revisions to the
production requirements for periods of shutdown. One commenter stated
that during shutdown, a kiln operator would not be pushing any cars in
the kiln after reaching a range of 250 to 300[emsp14][deg]F in the
exhaust stack (depending on the type of kiln and its operating
parameters). The commenter asked that a minimum operating range be
allowed during a shutdown cycle. Another commenter noted that a
limitation for a kiln to cease charging in new product before a kiln
stops venting to an APCD may be a reasonable alternative to temperature
requirements.
    Response: The EPA evaluated the comments and additional information
received following proposal as described in section IV.A.4 of this
preamble. As a result, the EPA has revised the work practice standards
for periods of startup and shutdown for BSCP tunnel kilns to provide
requirements that are more representative of the best performing kilns.
Specifically, instead of defining the minimum inlet APCD temperature as
400 [deg]F, the EPA is requiring the owner or operator to determine the
minimum inlet temperature for each APCD. If a kiln does not have an
APCD, the owner or operator is required to determine the product-
specific kiln temperature profile that must be achieved before the kiln
can reach full production. In addition, instead of specifying that no
product can be introduced to the kiln during startup, the EPA is
requiring the owner or operator to determine the production rate needed
to start up the kiln. The final startup standards specify that this
startup production rate cannot be exceeded until the kiln exhaust
reaches the APCD minimum inlet temperature or the product-specific kiln
temperature profile, whichever is applicable. The final shutdown
standards specify that no additional product can be introduced once the
kiln exhaust falls below the APCD minimum inlet temperature or the
product-specific kiln temperature profile, whichever is applicable.

C. Clay Ceramics Manufacturing NESHAP

1. Authority
    Comment: Two commenters argued that the EPA has no legal authority
to finalize major source NESHAP for the ceramic tile manufacturing
industry \104\

because there are currently no existing major sources in that industry
sector that will be subject to the standards. Specifically, they argued
that CAA section 112(d)(1) only provides the EPA authority to regulate
a category or subcategory if it has major sources. Commenters contended
that, here, ceramic tile manufacturing facilities that emit HAP have
all become synthetic area sources and so are subject to the ``area
source'' NESHAP regulation. Thus, they argue, the law does not allow
the EPA to proceed with a major source standard for these
subcategories. Both commenters also stated that the CAA does not give
the EPA the authority to regulate ``just-in-case'' there is a major
source in the future, and the EPA may only regulate categories and
subcategories that currently have major sources in them.
---------------------------------------------------------------------------

    \104\ There are three distinct sectors within the clay ceramics
manufacturing industry: ceramic floor tile manufacturing, ceramic
wall tile manufacturing, and sanitaryware manufacturing. These
comments address the regulation of HAP emissions from ceramic floor
tile manufacturing and ceramic wall tile manufacturing.
---------------------------------------------------------------------------

    One commenter stated that the EPA should not devote resources to
finalizing these regulations when those regulations would apply to no
one, and, thus, will have no environmental benefits. The commenter
stated that it is the EPA's duty to responsibly steward the public
resources with which it has been entrusted to use in fulfillment of its
mission, and using these resources to issue regulations that will
regulate no one fails to satisfy that responsibility. Issuing such
regulations is expensive for the regulated community and has the real
potential to create unintended, inaccurate impressions of the industry,
its emissions and its products. It serves no public purpose, and will
impose short and long term costs on the EPA, and long term costs on
delegated states as an unfunded mandate and on the tile manufacturing
industry, 79 FR 75671 (Dec. 18, 2014).
    The commenter argued that, because the EPA's promulgation of
standards for the ceramic tile industry is not authorized by the CAA,
finalizing such standards would violate Articles I and II of the U.S.
Constitution because it is an attempt by the EPA to rewrite portions of
the CAA when the power to enact laws is reserved to Congress. The
commenter stated that Congress provided clear instructions to the EPA,
in the unambiguous numerical definition of ``major source,'' as to
which industry categories or subcategories could be regulated by major
source NESHAP standards. The commenter noted that the Supreme Court
very recently stated: ``An agency may not rewrite clear statutory terms
to suit its own sense of how the statute should operate.'' Util. Air
Regulatory Grp. v. EPA, 134 S.Ct. 2427, 2446 (2014). Further, the Court
stated: ``We are not willing to stand on the dock and wave goodbye as
EPA embarks on a multiyear voyage of discovery.'' 134 S.Ct. at 2446.
The commenter asserted that the Supreme Court's concerns in the UARG
case are instructive here because, as in the UARG case, the statute
creates unambiguous numeric thresholds defining a major source: the
emission of 10 tpy any one HAP or the emission of 25 tpy in the
aggregate of all HAP, 42 U.S.C. 9612(a)(l). The commenter contended
that the Supreme Court supported the commenter's position when it
stated that ``[i]t is hard to imagine a statutory term less ambiguous
than the precise numerical thresholds . . .'' Id. at 2445.
    The commenter argued that the Sierra Club consent decree is
irrelevant to the EPA's statutory authority and its limitations. The
consent decree entered in the case of Sierra Club v. EPA, 850 F.2d 300
(D.D.C. 2012) (hereafter the ``consent decree'') is germane to the
timing of this rulemaking, but it does not, and legally could not,
expand CAA section 112(d) to grant the EPA legal authority to regulate
on the just-in-case basis the EPA has proposed. The withdrawal of the
proposed NESHAP does not preclude the EPA from meeting its statutory
obligations, fulfilling the requirements of the consent decree, and
continuing its existing precedent. The EPA may issue final NESHAP for
those subcategories within this category in which a major source
exists. The ceramic tile manufacturing industry is not among them.
    The commenter argued that the proposed NESHAP would, if finalized
as proposed, be arbitrary and capricious because the proposed NESHAP is
based on hypothetical or imaginary manufacturing and air emissions
control strategies, flawed data from an invalidated stack test method,
and on statistically created emissions data. The EPA even proposed in
places not to use actual emissions data.
    According to the commenter, the EPA's proposal, if finalized, would
create an economic hurdle so high that no one in the industry would
expand their business to the point of becoming a NESHAP major source.
Further, a substantial number of these entities meet the definition of
a ``small business'' as defined by the U.S. Small Business
Administration (SBA). The result of this regulation, if finalized,
would be to hand non-market-based economic advantages to foreign
producers to grow their presence in the U.S. market by importing their
competing ceramic tile. Financing of capital projects will be adversely
affected by the costs imposed by the NESHAP, further raising the
economic hurdle. Major source domestic manufacturing capacity will not
be built, and the jobs and tax base that go along with that capacity
will not be created.
    Response: Under CAA section 112(c)(1), the EPA first lists all
categories and subcategories of major sources. It is at this first step
that the EPA determines that a given category or subcategory contains
major sources of HAP. Then, the EPA sets standards for those listed
categories and source categories. Both CAA section 112(c)(2) and CAA
section 112(d)(1) make clear that the EPA is to regulate all listed
categories and subcategories. As CAA section 112(c)(2) states: ``For
the categories and subcategories the Administrator lists, the
Administrator shall establish standards . . .'' As CAA section
112(d)(1) states: ``The Administrator shall promulgate regulations
establishing emissions standards for each category and subcategory of
major sources and area sources of hazardous air pollutants listed for
regulation pursuant to subsection (c) of this section . . .'' In short,
once a category or subcategory of major sources is listed under CAA
section 112(c), it must be regulated. If commenters believe that the
major source ceramic tile subcategories should not be regulated, they
may seek to delete these subcategories from the list, which is a
process that Congress established in CAA section 112(c)(9) and which
the DC Circuit has held is the EPA's sole authority for removing a
listed category or subcategory from the list. New Jersey v. EPA, 517
F.3d 574, 581-583 (D.C. Cir. 2008).
    In interpreting the relevant provisions here, the EPA is mindful of
the recent and longstanding instructions from the Supreme Court that
statutory provisions must be read to further rather than undermine
Congress's statutory intent. King v. Burwell, 2015 U.S. Lexis 4248, *29
(2015)(``We cannot interpret federal statutes to negate their own
stated purposes.'')(citing and quoting New York State Dept. of Social
Servs. v. Dublino, 413 U. S. 405, 419-420, 93 S. Ct. 2507, 37 L. Ed. 2d
688 (1973)); E.I. Du Pont De Nemours v. Train, 430 U.S. 112, 132
(1977)(``We cannot, in these circumstances, conclude that Congress has
given authority inadequate to achieve with reasonable effectiveness the
purposes for which it has acted.'')(quoting Permian Basin Area Rate
Cases, 390 U.S. 747, 777 (1968)). In this context, it is unreasonable
to read

CAA section 112(d)(1) as limiting the EPA's authority to set standards
that will be applicable to the highest emitting sources in a category
or subcategory and creating a loophole by which major sources can evade
regulation. Without suggesting that the following is the commenters'
intent, the effect of the commenters' interpretation of CAA section 112
would be that major sources would be able to evade regulation by,
first, becoming synthetic area sources during the rulemaking process
(which, under the commenters' view, would preclude the EPA from
finalizing standards for major sources) and then, after the EPA
withdraws the proposed standards, reconverting to be major sources and
thus not subject to any standard. Consideration of this scenario is
particularly appropriate in the circumstances here, because there are
standards in place for area sources in the ceramic tile subcategories.
It is not reasonable to interpret CAA section 112 to create a structure
where an area source (whether a natural area source or a synthetic area
source) has an incentive to increase emissions to become a major
source, and by doing so is no longer subject to emissions limitations.
    Further, the issue of whether there are major sources in the
ceramic tile subcategories is not as clear as the commenters presume.
Even if, as the commenters contend, all of the existing major sources
in these subcategories have successfully completed the process of
becoming synthetic area sources, then these sources are not subject to
the requirements imposed on major sources but that does not equate to a
conclusion that they are no longer major sources in any respect. The
EPA's view is that synthetic area sources, though subject to area
source requirements rather than major source requirements, are still
major sources in certain respects. For example, synthetic area sources
are considered to be major sources when the EPA identifies the best
performing major sources as part of a MACT floor calculation under CAA
section 112(d). Further, CAA section 112(a)(1) defines a major source
as ``any stationary source or group of stationary sources located
within a contiguous area and under common control that emits or has the
potential to emit considering controls, in the aggregate, 10 tons per
year or more of any hazardous air pollutant or 25 tons per year or more
of any combination of hazardous air pollutants.'' The reference to a
source's ``potential to emit considering controls'' in this definition
allows the interpretation that a source's potential to emit before and
after controls is relevant, such that synthetic area sources may be
considered within the meaning of this definition.
    With respect to the commenter's argument that CAA section 112 does
not authorize ``just in case'' regulation, that is both not correct and
off point. First, CAA section 112 clearly provides that the EPA will
set standards for new sources in the listed categories and
subcategories notwithstanding that the EPA can never know whether there
will actually be any new sources. As required under CAA section 112,
the EPA establishes new source standards ``just in case'' (to use
commenter's phrasing) new sources come into existence. Second, as
discussed above, it is reasonable for the EPA to promulgate major
source standards where, as here, there are synthetic area sources that
could revert to major sources just in case that happens.
    With respect to the commenters' argument that it is a poor use of
agency resources for the EPA to finalize standards for the ceramic tile
subcategories, the EPA has considered whether it is better to complete
the current rulemaking with respect to the ceramic tile subcategories
(and have them in place in the event that there are new major sources
or a synthetic area source reverts to major source status) or to take
no action now and re-do this rulemaking with respect to these
subcategories in the event that there are major sources in the future.
The EPA's conclusion is that, having gotten this far along in the
rulemaking process, it is a better use of agency resources to finalize
requirements for the ceramic tile subcategories now. Given the options,
finalizing these requirements in this rulemaking requires only a modest
amount of additional resources, and is a much more efficient use of
agency resources than restarting and repeating the rulemaking process
at some point in the future. Even if one considers that there may not
be any major sources that become subject to these requirements and that
such a rulemaking might not ever be done, the EPA's judgment is still
that it is more efficient and a more cost-effective use of agency
resources to finalize these requirements now. Finally, on the issue of
how likely it is that major sources will be built in the future, the
EPA notes that the commenters' own arguments suggest they will be.
Specifically, the commenters stated that having a major source standard
in place will dissuade companies from expanding small facilities into
major sources and will impede financing for new major sources. The
premise of such a comment is that, in the absence of a standard, there
will be such expansions and new major sources.
    The document ``National Emission Standards for Hazardous Air
Pollutants for Clay Ceramics Manufacturing: Background Information for
Final Rule--Summary of Public Comments and Responses'' in Docket ID No.
EPA-HQ-OAR-2013-0290 addresses additional comments on this topic.
    Comment: According to one commenter, the EPA failed to demonstrate
that the benefits of this proposed arbitrary and capricious NESHAP
justify the costs. As stated in Executive Order 13563, ``Improving
Regulation and Regulatory Review,'' issued by President Obama on
January 18, 2011 to reaffirm Executive Order 12866, ``[e]ach agency
must . . . propose or adopt a regulation only upon a reasoned
determination that its benefits justify its costs.'' The preamble to
the proposed NESHAP provides cost information (which the commenter
noted elsewhere is erroneous) but did not discuss the benefits. The EPA
only articulated the benefits of the BSCP Manufacturing NESHAP. With
respect to costs, the EPA's cost analysis failed to account for costs
to the agency and delegated states to promulgate and implement the
regulations. There are no benefits to justify any of these costs.
Further, ``[i]n deciding whether and how to regulate, agencies should
assess all costs and benefits of available regulatory alternatives,
including the alternative of not regulating.'' The EPA did not assess
the alternative of not regulating--a path that would have exactly the
same result, as there are no major sources to be regulated or not
regulated. Therefore, the commenter stated that the EPA failed to meet
its burden; the proposed NESHAP does not have benefits justifying its
costs, and therefore such a regulation cannot be adopted.
    Response: We disagree with the commenter. First, CAA section 112
clearly states that the EPA is obligated to regulate emissions of HAP
from listed source categories. There is no benefits test in the
statutory requirement. The language in Executive Order 12866 does not
supersede a clear legal requirement in the CAA. Second, because there
are no major sources that will be regulated by this rule at the present
time, there will be no implementation costs for the rule. If at a later
date a major source is constructed, or a non-major source becomes
major, then there will be implementation costs, but this rule will
result in emission reduction requirements compared to the emissions
that would be expected to occur in the absence of a rule. Therefore, at
the point

where this rule actually results in costs, it will also have
corresponding benefits. In the absence of any current major sources
that will be covered by this rule, we simply cannot calculate the
benefits.
2. MACT Floors
    Comment: One commenter disagreed with the inclusion of emissions
data from Kohler's South Carolina facility tunnel kiln with the wet
scrubber in the sanitaryware tunnel kiln existing source data pool for
MACT floor determination. The commenter stated that Kohler installed a
new tunnel kiln at the South Carolina facility in 2005 under the Clay
Ceramics Manufacturing NESHAP promulgated in 2003, which, according to
the commenter, required the installation of APCD on any new first-fire
tunnel kilns to meet the HF and HCl emission limitations. The APCD that
Kohler installed, a wet scrubber, was written into the facility's air
permit at the time, and so its use at that time was federally
enforceable. The court vacated the Clay Ceramics Manufacturing NESHAP
in 2007, and the South Carolina Department of Health and Environmental
Control revised the facility's air permit in March 2009, removing any
reference to the Clay Ceramics Manufacturing NESHAP and any requirement
to operate the scrubber. Kohler then permanently shut down the scrubber
in March 2009, though they continued to operate the tunnel kiln per
permit requirements. Due to cost considerations, the scrubber was
abandoned in place and not demolished/removed.
    The commenter noted that, when the EPA issued the information
collection request (ICR) for clay ceramics emissions test data in 2010,
the EPA required that Kohler make operational that wet scrubber for
emissions testing of that tunnel kiln, even though the APCD was not
listed in any permit nor required under any rule and had not been
operated in 17 months. Initially, Kohler agreed to test the kiln as an
existing source per operational requirements in the facility's air
permit (i.e., without the wet scrubber). However, the EPA demanded that
Kohler restart and operate the abandoned scrubber during the kiln's
emissions testing. The commenter noted that Kohler cooperated with the
EPA and tested emissions with the scrubber operating, but the scrubber
was immediately shut down after testing. This scrubber has operated for
a total of 1 week in the past 6 years, and that short period of
operation was only to comply with the EPA's ICR testing demand.
    The commenter acknowledged that the EPA has the authority require
operation of any permitted source for emissions testing under
rulemaking and ICR protocol. The commenter agreed with the EPA that the
``kiln'' in question is an existing source but disagreed that the non-
operating wet scrubber qualifies as part of an existing source. The
commenter contended that the EPA is arbitrarily penalizing Kohler for
not spending the money to demolish and remove the wet scrubber back in
2009 when it was removed from the facility's air permit. The commenter
asserted that the test data from the wet scrubber are not
representative of any existing source and were not actually achieved in
practice over time. Therefore, using the test data in the MACT floor
analysis is inconsistent with the EPA's expressed intent to determine
MACT floors for existing sources based on the average emissions
actually achieved in practice by the best performing sources with
consideration for variability in emissions over time. The commenter
asserted that all emissions data from the wet scrubber should be
excluded from the existing source data pool for MACT floor analysis,
and the existing source floors should be recalculated for the remaining
existing sources.
    Response: Data from the APCD the commenter refers to was considered
in developing both the new and existing MACT floors for sanitaryware
kilns. As stated by the commenter, the APCD was installed to comply
with the previously promulgated Clay Ceramics Manufacturing NESHAP and
thus was an available data point for collection through the CAA section
114 data collection process for this rulemaking. Because this source
had an operational APCD (even though it was not being operated), we
believe that testing with the APCD operating would be most
representative of the source's best performance as defined in the CAA.
Having collected the emissions data for the source with the APCD
operating, the EPA considered the data consistent with section
112(d)(3)(B) of the CAA, under which the Administrator is required to
calculate ``the average emission limitation achieved by the best
performing 5 sources (for which the Administrator has or could
reasonably obtain emissions information) in the category or subcategory
for categories or subcategories with fewer than 30 sources.'' Since it
is appropriate to include the data in the database available to
determine MACT floors, it is appropriate to use these data in floor
calculations, if it is actually part of the best performing facilities.
We note, however, that the data from this device was only significant
for the existing source dioxin/furan MACT floor, for reasons that are
dependent on each regulated pollutant and discussed as follows.
    For both new and existing PM MACT floors, the final limit was
unaffected by use of these data, since the data from the APCD was not
ranked in the top five sources with data.
    For both new and existing Hg MACT floors, the data from the APCD
were not ranked because the data were invalidated. The data were
removed from the dataset because of errors in the analytical procedures
surrounding the digestion process as dictated by Method 29. See Section
4.1: Analytical discrepancy of the Test Report ``Kohler Co.,
Spartanburg, SC: Tunnel Kilns and Glaze Spray Booths 08/11-17/2010
Stack Test,'' Docket Item No. EPA-HQ-OAR-2013-0290-0069.
    For dioxin/furan, the data from the APCD are in the top five but is
not the best performing unit based on the dioxin/furan ng/kg ranking.
(Note the units of measure for dioxin/furan ranking have changed from
the proposed ng/dscm at 7-percent O2 to ng/kg.) For the
existing source floor, the result of the calculation of the best
performing five sources is 3.3 ng/kg with the data point, and would
have been 4.0 ng/kg without the data point, which we consider a nominal
difference. The difference does not result in any source having to add
controls. The calculation of the new source floor was not affected by
the data from the APCD because, as stated above, the source was not the
best performing unit, and the new source floor is based on the best
performing unit.
    Comment: Three commenters questioned EPA's decision to propose the
dioxin/furan emission limits for ceramic tile manufacturing and
sanitaryware manufacturing in concentration format only. Two commenters
stated that the final dioxin/furan standards should provide the option
to comply with a limitation expressed in units of nanograms per
milligram of tile produced, in addition to or in lieu of the proposed
standard stated in ng/dscm. A mass-based production-related standard
effectively removed the issues around O2 correction created
by use of a standard based only on concentration. Further, the
commenters asserted that it is a more universally appropriate
adjustment for comparison of emissions from large kilns having high air
flow rates to emissions from small kilns with low air volumes. The
third commenter agreed and noted that the proposed

limits for PM and Hg are expressed as lb/ton fired product. The
commenter asked EPA to explain how the concentration format for the
emission limit is more appropriate for dioxins/furans than a mass
throughput limit. If it is not, the commenter suggested using a mass
throughput format for the dioxin/furan emission limit.
    Response: The dioxin/furan limits provided in the final rule for
clay ceramics are in units of ng TEQ/kg of throughput fired or
processed. The EPA agrees that this change in format eliminates the
questions surrounding the O2 correction for concentration
values and is more consistent with the other units of measure provided
in the Clay Ceramics Manufacturing NESHAP. To demonstrate compliance
with the limits, the owner or operator will determine the mass TEQ for
each test run (using the toxic equivalency factors in Table 5 to
subpart KKKKK), divide the mass TEQ by the production rate during the
test run, and average the test runs.
    The production-based dioxin/furan limits are provided in lieu of
the proposed concentration limits. The compliance flexibility provided
to the BSCP Manufacturing source category (including alternative
compliance options for PM and Hg) was solely related to concerns under
the Small Business Regulatory Enforcement Fairness Act (SBREFA),
specifically reducing the regulatory burden of the numerous small
entities in the BSCP category. There are no small businesses expected
to be subject to the Clay Ceramics Manufacturing NESHAP, so the EPA
determined that no additional compliance flexibility was necessary or
warranted for the Clay Ceramics Manufacturing source category.
3. Startup and Shutdown
    Comment: One commenter challenged the proposed startup and shutdown
regulations for ceramic tile manufacturing. The commenter asserted that
these standards are based conceptually on the desire to minimize the
time during which ceramic tile manufacturing process units operate in a
temperature range that is ``conducive'' to the formation of new
dioxins/furans (i.e., 200-450 degrees Celsius). The commenter stated
that this concern is moot because there are no new dioxins/furans
formed in the ceramic tile industry sector, based on the emissions data
the EPA proposed to use to set MACT floors for ceramic tile sources and
on the fact that ceramic tile dioxin/furan congener profiles are
different from the profile of the dioxins/furans created as a product
of combustion.
    The commenter also challenged the EPA's startup and shutdown
proposal for spray dryers relative to dioxins/furans. The input to the
spray dryer experiences no more than 212[emsp14][deg]F because the
operational purpose of the spray dryer is to cause the excess moisture
suspended or attached to the ball clay matrix to evaporate. If any
spray dryer operating temperature is relevant to the EPA's concern
about temperatures in a spray dryer conducive to dioxin/furan
formation, this is the correct focus.
    For ceramic tile floor tile and wall tile roller kilns, the
commenter stated that the proposed temperature requirements for startup
and shutdown reflect good kiln production practices; therefore, the
proposed startup and shutdown standards are unnecessary.
    The commenter noted that the standards are based only on data from
the BSCP subcategory, and the proposed temperatures are not appropriate
for all sources. For example, ceramic tile dryers uniformly operate
below 400[emsp14][deg]F, so product could never be introduced to a tile
dryer. The commenter also noted that the startup provisions require
startup of APCD at 400[emsp14][deg]F. However, ceramic tile dryers do
not have APCD because they burn only natural gas, their normal
operating temperature is less than 400[emsp14][deg]F, and their
resulting emissions are minimal. For these reasons, the proposal
effectively constitutes a ban on the operation of tile dryers. If tile
dryers are not an available manufacturing process, ceramic tile
manufacturing as it is currently conducted in the United States would
effectively cease at major sources. The commenter stated that the EPA
lacks the legal authority to implement a de facto shut down of major
sources, or to bar the possibility of the proposal of a major source,
in this industry.
    For all the above reasons, the commenter asserted that the EPA must
withdraw the startup and shutdown proposal from any final NESHAP for
this subcategory. The commenter contended that, as proposed, these
standards are arbitrary and capricious.
    Response: The CAA requires that NESHAP emissions limitations under
section 112 must apply continuously, including during periods of
startup and shutdown. As noted in the preamble to the proposed rule, we
recognize that it is not feasible to conduct emission testing during
periods of startup and shutdown; therefore, owners and operators would
be unable to demonstrate compliance with the final numeric MACT
standards during those periods. Therefore, the EPA is finalizing work
practice standards for periods of startup or shutdown to ensure that
the Clay Ceramics Manufacturing NESHAP includes continuous CAA section
112-compliant standards.
    The commenter is correct that the specific startup and shutdown
work practice standards proposed were based on information from the
BSCP industry. In absence of any data on specific startup and shutdown
procedures from the clay ceramics CAA section 114 survey, the EPA used
the only data available for a similar industry. The EPA has not
received any additional information from clay ceramics manufacturers on
specific procedures, and in light of that lack of data, the EPA
maintains that the less prescriptive startup and shutdown work
practices being finalized for the BSCP industry are appropriate for the
clay ceramics industry. First, one of the commenter's main points is
that the specific temperatures that were proposed are not appropriate
for all the types of units to which the standards were proposed to
apply, which is consistent with comments received on the BSCP proposal.
Second, the commenter did note that the proposed standards reflect good
kiln production practices for one type of process unit for which the
specific temperature was appropriate. Therefore, the EPA is finalizing
work practice standards that are based on best practices but are less
prescriptive than the proposed standards.
    As a final note, the EPA is clarifying in this response that the
startup and shutdown standards are not intended to minimize only
emissions of dioxins/furans. Instead, the standards are intended to
minimize emissions of all pollutants by limiting the amount of
throughput being processed before the unit reaches full production and
limiting the amount of time the exhaust is not being routed to the
APCD, if applicable. In addition, the proposed startup and shutdown
work practice requirements did not require the use of an APCD, nor do
the final standards. The standards only specify the requirements for
routing exhaust to an APCD if one is present. The EPA has reviewed the
language in the final rule to ensure the standards are clear.

VI. Summary of the Cost, Environmental, Energy and Economic Impacts

A. What are the cost and emissions reduction impacts?

    Table 8 of this preamble illustrates the costs and emissions
reductions for existing sources under the final BSCP Manufacturing
NESHAP and final Clay Ceramics Manufacturing NESHAP. The

costs include the costs of installing APCD as well as the costs for the
testing and monitoring needed to demonstrate compliance.

                           Table 8--Summary of Costs and Emissions Reductions for BSCP and Clay Ceramics Existing Sources \a\
                                                                     [2011 dollars]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                               Cost (million)                                   Emissions reductions (tpy)
                                           -------------------------------------------------------------------------------------------------------------
                                                                                Non-Hg
                 Industry                                                                             HAP
                                             Capital     Annual       HF        HCl        Cl2       metals       Hg         PM     PM2.5 \c\     SO2
                                                                                \b\
--------------------------------------------------------------------------------------------------------------------------------------------------------
BSCP......................................      $64.6      $24.6        344       22.1       2.04       7.08     0.0733        643        309        205
Clay Ceramics.............................      0.267     0.0924          0          0          0          0          0          0          0          0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Includes costs for APCD, testing and monitoring.
\b\ Includes antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, nickel and selenium.
\c\ PM2.5 = particulate matter with particles less than 2.5 micrometers in diameter.

    The nationwide capital and annual costs of the APCD, testing, and
monitoring needed to comply with the final BSCP Manufacturing NESHAP
are expected to total $64.6 million and $24.6 million, respectively
(2011 dollars). The nationwide HAP emissions reductions achieved under
the final BSCP Manufacturing NESHAP are expected to total 375 tpy. The
methodology used to estimate the nationwide costs and emissions
reductions of the final BSCP Manufacturing NESHAP is presented in the
technical memoranda titled ``Development of Cost and Emission Reduction
Impacts for the Final BSCP Manufacturing NESHAP'' and ``Monitoring and
Testing Requirements and Costs for the Final BSCP Manufacturing
NESHAP'' in Docket ID No. EPA-HQ-OAR-2013-0291.
    It is anticipated that all sanitaryware emission points will meet
the MACT floor emission limits in the final Clay Ceramics Manufacturing
NESHAP, so no emission control costs or emissions reductions are
expected for these sources. However, these facilities are expected to
incur $92,400 annually in monitoring and testing costs to demonstrate
compliance with the final Clay Ceramics Manufacturing NESHAP. These
costs are documented in the technical memorandum titled, ``Monitoring
and Testing Requirements and Costs for the Final Clay Ceramics
Manufacturing NESHAP'' in Docket ID No. EPA-HQ-OAR-2013-0290.
    There are no major sources producing ceramic floor tile or ceramic
wall tile. The five facilities that were major sources at the time of
the 2008 and 2010 EPA surveys have already taken the necessary steps to
become synthetic area sources. Consequently, none of the known tile
facilities will be subject to the provisions of the Clay Ceramics
Manufacturing NESHAP, which means that no costs or emissions reductions
are expected for tile affected sources under the final Clay Ceramics
Manufacturing NESHAP.

B. What are the secondary impacts?

    Table 9 of this preamble illustrates the secondary impacts for
existing sources under the BSCP Manufacturing NESHAP and Clay Ceramics
Manufacturing NESHAP.

                                                      Table 9--Summary of Secondary Impacts for BSCP and Clay Ceramics Existing Sources \a\
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Secondary air emissions (tpy)                                      Energy
                            Industry                             ------------------------------------------------------------------------------------------------     impacts       Solid waste
                                                                        PM             PM2.5            CO              NOX             SO2             CO2         (MMBtu/yr)    impacts  (tpy)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
BSCP............................................................            3.40            1.14            5.74            45.6             133          27,900         461,000           5,210
Clay Ceramics...................................................               0               0               0               0               0               0               0               0
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ CO = carbon monoxide; CO2 = carbon dioxide; MMBtu/yr = million British thermal units per year.

    The relevant secondary impacts that were evaluated for the BSCP
Manufacturing NESHAP and Clay Ceramics Manufacturing NESHAP include
secondary air emissions, energy impacts and solid waste impacts.
Indirect or secondary air emissions are impacts that result from the
increased electricity usage associated with the operation of APCD to
meet the promulgated limits (i.e., increased secondary emissions of
criteria pollutants from power plants). Energy impacts consist of the
electricity needed to operate the APCD, and solid waste impacts consist
of the particulate captured by the APCD that is disposed of as waste
(not reused or recycled).
    Under the final BSCP Manufacturing NESHAP, the nationwide secondary
emissions of the criteria pollutants PM, CO, NOX and
SO2 are expected to total 188 tpy, and secondary emissions
of the greenhouse gas pollutant CO2 are expected to total
27,900 tpy, with energy impacts of 461,000 MMBtu/yr and solid waste
impacts of 5,210 tpy. The methodology used to estimate the nationwide
secondary impacts of the final BSCP Manufacturing NESHAP is presented
in the technical memorandum, ``Development of Cost and Emission
Reduction Impacts for the Final BSCP Manufacturing NESHAP'' in Docket
ID No. EPA-HQ-OAR-2013-0291.
    As noted in the previous section, it is anticipated that all
sanitaryware emission points will meet the MACT floor emission limits
in the Clay Ceramics Manufacturing final rule, so there are no
secondary impacts expected for these sources. There are no major
sources producing ceramic floor tile or ceramic wall tile. The five
facilities that were major sources at the time of the 2008 and 2010 EPA
surveys have already taken the necessary steps to become synthetic area
sources. Consequently, none of the known ceramic tile facilities are
expected to be subject to the provisions of the Clay Ceramics
Manufacturing NESHAP, which means that no secondary impacts are
expected for ceramic tile affected sources under the final Clay
Ceramics Manufacturing NESHAP.

C. What are the economic impacts?

    For the BSCP Manufacturing source category, the average national
brick price under the promulgated standards increases by 1.8 percent or
$4.37 per

1,000 Standard Brick Equivalent (SBE) (2011 dollars), while overall
domestic production falls by 1.5 percent or 52 million bricks per year.
Under the promulgated standards, the EPA estimated that two to four
BSCP manufacturing facilities are at significant risk of closure.
    Based on the results of the small entity screening analysis for
BSCP Manufacturing, the EPA concluded that it is not able to certify
that the BSCP Manufacturing NESHAP will not have a significant impact
on a substantial number of small entities. As a result, the EPA
initiated a Small Business Advocacy Review (SBAR) Panel and undertook
an Initial Regulatory Flexibility Analysis (IRFA).
    For Clay Ceramics Manufacturing, one sanitaryware company owns
major sources and will incur costs (for testing, monitoring,
recordkeeping and reporting). That affected company is not a small
business. The compliance costs are less than 0.002 percent of sales for
the affected company. Hence, the economic impact for compliance is
minimal. As noted above, there are no major sources producing ceramic
floor tile or ceramic wall tile. Because no small firms face
significant control costs, there is no significant impact on small
entities. Thus, the Clay Ceramics Manufacturing regulation is not
expected to have significant impact on a substantial number of small
entities.
    For more information on the benefits analysis and market analyses,
please refer to the Regulatory Impact Analysis (RIA) for the BSCP
Manufacturing NESHAP, ``Regulatory Impact Analysis: Final Brick and
Structural Clay Products NESHAP,'' which is available in Docket ID No.
EPA-HQ-OAR-2013-0291.

D. What are the benefits?

    Emission controls installed to meet the requirements of this rule
will generate benefits by reducing emissions of HAP as well as criteria
pollutants and their precursors, NOX and SO2.
Sulfur dioxide and NOX are precursors to PM2.5,
and NOX is a precursor to ozone. The criteria pollutant
benefits are considered co-benefits for this rule. For this rule, we
were only able to quantify the health co-benefits associated with
reduced exposure to PM2.5 from changes in emissions directly
emitted PM2.5, SO2, and NOX. We
estimate the monetized co-benefits of the BSCP Manufacturing NESHAP in
2018 to be $83 million to $190 million (2011 dollars) at a 3-percent
discount rate and $75 million to $170 million (2011 dollars) at a 7-
percent discount rate, not including consideration of energy
disbenefits. Using alternate relationships between PM2.5 and
premature mortality supplied by experts, higher and lower co-benefits
estimates are plausible, but most of the expert-based estimates fall
between these two estimates.\105\ A summary of the emission reduction
and monetized co-benefits estimates for this BSCP Manufacturing NESHAP
at discount rates of 3 percent and 7 percent is illustrated in Table 10
of this preamble.
---------------------------------------------------------------------------

    \105\ Roman, et al., 2008. ``Expert Judgment Assessment of the
Mortality Impact of Changes in Ambient Fine Particulate Matter in
the U.S.,'' Environ. Sci. Technol., 42, 7, 2268-2274.

    Table 10--Summary of the Monetized PM[bdi2].[bdi5] Co-Benefits for the BSCP Manufacturing NESHAP in 2018
                                       [Millions of 2011 dollars] \a\ \b\
----------------------------------------------------------------------------------------------------------------
                                             Emission         Total monetized co-         Total monetized co-
                Pollutant                   reductions        benefits (3 percent         benefits (7 percent
                                               (tpy)               discount)                   discount)
----------------------------------------------------------------------------------------------------------------
Directly emitted PM[bdi2].[bdi5]........             308  $83 to $190...............  $75 to $170.
PM[bdi2].[bdi5] precursors
    SO[bdi2]............................              72  $2.9 to $6.6..............  $2.6 to $6.0.
    NOX \c\.............................             -46  -$0.29 to -$0.66..........  -$0.26 to -$0.59.
                                         -----------------------------------------------------------------------
        Total monetized benefits........  ..............  $84 to $190...............  $76 to $170.
----------------------------------------------------------------------------------------------------------------
\a\ All estimates are for the analysis year and are rounded to two significant figures so numbers may not sum
  across rows. The total monetized co-benefits reflect the human health benefits associated with reducing
  exposure to PM[bdi2].[bdi5] through reductions of PM[bdi2].[bdi5] precursors, such as SO[bdi2] and directly
  emitted PM[bdi2].[bdi5]. It is important to note that the monetized co-benefits do not include reduced health
  effects from exposure to HAP, direct exposure to nitrogen dioxide (NO[bdi2]), exposure to ozone, ecosystem
  effects or visibility impairment.
\b\ PM co-benefits are shown as a range from Krewski, et al. (2009) to Lepeule, et al. (2012). These models
  assume that all fine particles, regardless of their chemical composition, are equally potent in causing
  premature mortality because the scientific evidence is not yet sufficient to allow differentiation of effects
  estimates by particle type.
\c\ These emission reductions are the net emission reductions from the rule after subtracting out secondary
  emission increases due to additional energy requirements to run the control equipment. These estimates do not
  include monetized CO2 disbenefits, which range from $0.3 to $3 million depending on the discount rate. See the
  RIA for more information about how the EPA monetized these disbenefits.

    These co-benefits estimates represent the total monetized human
health benefits for populations exposed to less PM2.5 from
controls installed to reduce air pollutants in order to meet this rule.
Due to analytical limitations, it was not possible to conduct air
quality modeling for this rule. Instead, we used a ``benefit-per-ton''
approach to estimate the benefits of this rulemaking. To create the
benefit-per-ton estimates, this approach uses a model to convert
emissions of PM2.5 precursors into changes in ambient
PM2.5 levels and another model to estimate the changes in
human health associated with that change in air quality, which are then
divided by the emissions in specific sectors. These benefit-per-ton
estimates were derived using the approach published in Fann, et al.
(2012),\106\ but they have since been updated to reflect the studies
and population data in the 2012 p.m. National Ambient Air Quality
Standards (NAAQS) RIA.\107\ Specifically, we multiplied the benefit-
per-ton estimates from the ``Non-EGU Point other'' category by the
corresponding emission reductions.\108\ All national-average benefit-
per-ton estimates reflect the geographic distribution of the modeled
emissions, which may not exactly match the

emission reductions in this rulemaking and, thus, they may not reflect
the local variability in population density, meteorology, exposure,
baseline health incidence rates or other local factors for any specific
location. More information regarding the derivation of the benefit-per-
ton estimates for this category is available in the technical support
document, which is available as Docket Item No. EPA-HQ-OAR-2013-0291-
0089.
---------------------------------------------------------------------------

    \106\ Fann, N., K.R. Bakerand C.M. Fulcher. 2012.
``Characterizing the PM2.5-related health benefits of
emission reductions for 17 industrial, area and mobile emission
sectors across the U.S.'' Environment International 49 41-151.
    \107\ U.S. Environmental Protection Agency (U.S. EPA). 2012.
Regulatory Impact Analysis for the Final Revisions to the National
Ambient Air Quality Standards for Particulate Matter. EPA-452/R-12-
003. Office of Air Quality Planning and Standards, Health and
Environmental Impacts Division. December. Available at http://www.epa.gov/pm/2012/finalria.pdf.
    \108\ U.S. Environmental Protection Agency. 2013. Technical
support document: Estimating the benefit per ton of reducing PM2.5
precursors from 17 sectors. Research Triangle Park, NC. January.
---------------------------------------------------------------------------

    These models assume that all fine particles, regardless of their
chemical composition, are equally potent in causing premature mortality
because the scientific evidence is not yet sufficient to allow
differentiation of effects estimates by particle type. Even though we
assume that all fine particles have equivalent health effects, the
benefit-per-ton estimates vary between precursors depending on the
location and magnitude of their impact on PM2.5 levels,
which drive population exposure.
    It is important to note that the magnitude of the PM2.5
co-benefits is largely driven by the concentration response function
for premature mortality. We cite two key empirical studies, one based
on the American Cancer Society cohort study \109\ and the extended Six
Cities cohort study.\110\ In the RIA for the final rule, which is
available in Docket ID No. EPA-HQ-OAR-2013-0291, we also include
benefits estimates derived from expert judgments (Roman, et al., 2008)
as a characterization of uncertainty regarding the PM2.5-
mortality relationship.
---------------------------------------------------------------------------

    \109\ Krewski, C.A., III, R.T. Burnett, M.J. Thun, E.E. Calle,
D. Krewski, K. Itoand G.D. Thurston. 2002. ``Lung Cancer,
Cardiopulmonary Mortalityand Long-term Exposure to Fine Particulate
Air Pollution.'' Journal of the American Medical Association
287:1132-1141.
    \110\ Lepeule J, Laden F, Dockery D, Schwartz J. 2012. ``Chronic
Exposure to Fine Particles and Mortality: An Extended Follow-Up of
the Harvard Six Cities Study from 1974 to 2009.'' Environ Health
Perspect. July; 120(7):965-70.
---------------------------------------------------------------------------

    Considering a substantial body of published scientific literature,
reflecting thousands of epidemiology, toxicology and clinical studies,
the EPA's Integrated Science Assessment for Particulate Matter \111\
documents the association between elevated PM2.5
concentrations and adverse health effects, including increased
premature mortality. This assessment, which was twice reviewed by the
EPA's independent SAB, concluded that the scientific literature
consistently finds that a no-threshold model most adequately portrays
the PM-mortality concentration-response relationship. Therefore, in
this analysis, the EPA assumes that the health impact function for fine
particles is without a threshold.
---------------------------------------------------------------------------

    \111\ U.S. Environmental Protection Agency (U.S. EPA). 2009.
Integrated Science Assessment for Particulate Matter (Final Report).
EPA-600-R-08-139F. National Center for Environmental Assessment--RTP
Division. December. Available on the Internet at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=216546.
---------------------------------------------------------------------------

    In general, we are more confident in the magnitude of the risks we
estimate from simulated PM2.5 concentrations that coincide
with the bulk of the observed PM concentrations in the epidemiological
studies that are used to estimate the benefits. Likewise, we are less
confident in the risk we estimate from simulated PM2.5
concentrations that fall below the bulk of the observed data in these
studies. Concentration benchmark analyses (e.g., lowest measured level
(LML) or one standard deviation below the mean of the air quality data
in the study) allow readers to determine the portion of population
exposed to annual mean PM2.5 levels at or above different
concentrations, which provides some insight into the level of
uncertainty in the estimated PM2.5 mortality benefits. There
are uncertainties inherent in identifying any particular point at which
our confidence in reported associations becomes appreciably less and
the scientific evidence provides no clear dividing line. However, the
EPA does not view these concentration benchmarks as a concentration
threshold below which we would not quantify health benefits of air
quality improvements.
    For this analysis, policy-specific air quality data are not
available due to time and resource limitations and, thus, we are unable
to estimate the percentage of premature mortality associated with this
specific rule's emission reductions at each PM2.5 level. As
a surrogate measure of mortality impacts, we provide the percentage of
the population exposed at each PM2.5 level using the source
apportionment modeling used to calculate the benefit-per-ton estimates
for this sector. Using the Krewski, et al. (2009) study, 93 percent of
the population is exposed to annual mean PM2.5 levels at or
above the LML of 5.8 [micro]g/m \3\. Using the Lepeule, et al. (2012)
study, 67 percent of the population is exposed above the LML of 8
[micro]g/m\3\. It is important to note that baseline exposure is only
one parameter in the health impact function, along with baseline
incidence rates, population and change in air quality. Therefore,
caution is warranted when interpreting the LML assessment for this rule
because these results are not consistent with results from rules that
model changes in air quality.
    Every benefit analysis examining the potential effects of a change
in environmental protection requirements is limited, to some extent, by
data gaps, model capabilities (such as geographic coverage) and
uncertainties in the underlying scientific and economic studies used to
configure the benefit and cost models. Despite these uncertainties, we
believe the benefit analysis for this rule provides a reasonable
indication of the expected health benefits of the rulemaking under a
set of reasonable assumptions. This analysis does not include the type
of detailed uncertainty assessment found in the 2012 PM2.5
NAAQS RIA \112\ because we lack the necessary air quality input and
monitoring data to run the benefits model. In addition, we have not
conducted air quality modeling for this rule, and using a benefit-per-
ton approach adds another important source of uncertainty to the
benefits estimates. The 2012 PM2.5 NAAQS benefits analysis
provides an indication of the sensitivity of our results to various
assumptions.
---------------------------------------------------------------------------

    \112\ U.S. Environmental Protection Agency (U.S. EPA). 2012.
Regulatory Impact Analysis for the Final Revisions to the National
Ambient Air Quality Standards for Particulate Matter. EPA-452/R-12-
003. Office of Air Quality Planning and Standards, Health and
Environmental Impacts Division. December. Docket Item No. EPA-HQ-
OAR-2013-0291-0087.
---------------------------------------------------------------------------

    It should be noted that the monetized co-benefits estimates
provided above do not include benefits from several important benefit
categories, including exposure to HAP, NOX and ozone
exposure, as well as ecosystem effects and visibility impairment.
Although we do not have sufficient information or modeling available to
provide monetized estimates for this rule, we include a qualitative
assessment of these unquantified benefits in the RIA for these
promulgated standards.
    The specific control technologies for this rule are anticipated to
have minor secondary disbenefits, including an increase of 41 tons of
NOX, about 3 tons of PM, less than 6 tons of CO and 121 tons
of SO2 each year. Because we do not currently have methods
to monetize emission changes of CO, only secondary effects of PM,
SO2, and NOX were included in the monetary
evaluation of the actual benefits.
    For more information on the benefits analysis, please refer to the
RIA for this rule, ``Regulatory Impact Analysis: Final Brick and
Structural Clay Products NESHAP,'' which is available in Docket ID No.
EPA-HQ-OAR-2013-0291.

VII. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders
can be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders.

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

    This action is an economically significant regulatory action that
was submitted to the Office of Management and Budget (OMB) for review.
Any changes made in response to OMB recommendations have been
documented in the dockets for this action. The EPA prepared an analysis
of the potential costs and benefits associated with this action. This
analysis is contained in ``Regulatory Impact Analysis: Final Brick and
Structural Clay Products NESHAP.'' A copy of the analysis is available
in the docket for the BSCP Manufacturing NESHAP (Docket ID No. EPA-HQ-
OAR-2013-0291) and the analysis is briefly summarized here.
    The EPA's study estimates that affected BSCP facilities will incur
total annualized costs of $24.6 million (2011 dollars) under the BSCP
Manufacturing NESHAP, including costs of emission controls, testing and
monitoring, along with recordkeeping and reporting costs for facilities
that have testing and monitoring. The EPA gathered information on firm
sales and overall industry profitability for firms owning affected BSCP
facilities. The EPA estimated that two to four BSCP manufacturing
facilities are at significant risk of closure under the final
standards.
    The EPA also conducted an assessment of the benefits of the final
rule, as described in section VI of this preamble. These estimates
reflect the monetized human health benefits of reducing cases of
morbidity and premature mortality among populations exposed to
PM2.5 reduced by this rule. Data, resource and
methodological limitations prevented the EPA from monetizing the
benefits from several important benefit categories, including benefits
from reducing exposure to 375 tons of HAP each year for the promulgated
standards, as well as ecosystem effects and visibility impairment. In
addition to reducing emissions of PM precursors such as SO2,
this rule will reduce several non-Hg HAP metals emissions (i.e.,
arsenic, cadmium, chromium, lead, manganese, nickel, and selenium) each
year. The EPA estimates the total monetized co-benefits to be $83
million to $190 million (2011 dollars) at a 3-percent discount rate and
$75 million to $170 million (2011 dollars) at a 7-percent discount rate
on a yearly average in 2018 for the promulgated standards.
    Based on the EPA's examination of costs and benefits of the final
BSCP Manufacturing NESHAP, the EPA believes that the benefits of the
BSCP Manufacturing NESHAP will exceed the costs.
    The EPA also examined the costs and economic impacts associated
with the Clay Ceramics Manufacturing NESHAP. The remaining firm with
major sources is estimated to incur costs as a result of the Clay
Ceramics Manufacturing final rule and the firm only incurs costs
associated with testing, monitoring, recordkeeping and reporting. Total
annualized costs are only $92,400 (2011 dollars) and the firm's
estimated costs of complying with the Clay Ceramics Manufacturing
NESHAP are less than 0.002 percent of sales.

B. Paperwork Reduction Act (PRA)

    The information collection activities in the BSCP Manufacturing
NESHAP and Clay Ceramics Manufacturing NESHAP have been submitted for
approval to OMB under the PRA. The ICR document that the EPA prepared
for the BSCP Manufacturing NESHAP has been assigned EPA ICR number
2509.01. The ICR document that the EPA prepared for the Clay Ceramics
Manufacturing NESHAP has been assigned EPA ICR number 2510.01. You can
find copies of the ICRs in the dockets for the BSCP Manufacturing
NESHAP and Clay Ceramics Manufacturing NESHAP, and they are briefly
summarized here. The information collection requirements are not
enforceable until OMB approves them.
    The information collected from respondents will be used by EPA
enforcement personnel to: (1) identify new, modified, reconstructed and
existing sources subject to the standards; (2) ensure that MACT is
being properly applied; and (3) ensure that the APCD are being properly
operated and maintained on a continuous basis. In addition, records and
reports are necessary to enable the EPA to identify facilities that may
not be in compliance with the standards. Based on the reported
information, the EPA can decide which facilities should be inspected
and what records or processes should be inspected at these facilities.
The records that facilities maintain will indicate to the EPA whether
the owners and operators are in compliance with the emission
limitations (including emission limits, operating limits) and work
practice standards. Much of the information the EPA would need to
determine compliance would be recorded and retained onsite at the
facility. Such information would be reviewed by enforcement personnel
during an inspection and would not need to be routinely reported to the
EPA.
    All information submitted to the EPA for which a claim of
confidentiality is made will be safeguarded according to EPA policies
set forth in title 40, chapter 1, part 2, subpart B--Confidentiality of
Business Information. (See 40 CFR 2; 41 FR 36902, September 1, 1976;
amended by 43 FR 39999, September 28, 1978; 43 FR 42251, September 28,
1978; and 44 FR 17674, March 23, 1979.)
    Potential respondents to the information collection requirements in
the BSCP Manufacturing NESHAP are owners and operators of new and
existing sources at BSCP manufacturing facilities. A BSCP facility
manufactures brick, including face brick, structural brick, brick
pavers, or other brick and/or structural clay products including clay
pipe; roof tile; extruded floor and wall tile; or other extruded,
dimensional clay products. The BSCP facilities typically form, dry and
fire bricks and shapes that are composed primarily of clay and shale.
Kilns are used to fire BSCP. The rule applies to all new and existing
tunnel and periodic kilns at BSCP facilities.
    Potential respondents to the information collection requirements in
the Clay Ceramics Manufacturing NESHAP are owners and operators of new
and existing sources at clay ceramics manufacturing facilities. A clay
ceramics facility manufactures pressed floor tile, pressed wall tile,
or sanitaryware (e.g., sinks and toilets). Clay ceramics facilities
typically form, dry and fire tile or sanitaryware products that are
composed of clay, shale and various additives. Spray dryers are used
during the forming process at tile facilities to process the ceramic
mix into a powder to allow tile pressing. Dryers are used to reduce the
moisture content of the ceramic products prior to firing. Glazes are
applied to some tile and sanitaryware products, with glaze spraying
accounting for all glazing emissions. Kilns are used to fire the
ceramic products and include ceramic tile roller kilns and sanitaryware
tunnel and shuttle kilns. The rule applies to all existing, new and
reconstructed affected sources, which include the kilns, glaze spray
operations, ceramic tile spray dryers and floor tile press dryers.
(Wall tile press dryers and sanitaryware ware

dryers, with no measurable emissions, are not covered.)
    The information requirements are based on notification,
recordkeeping and reporting requirements in the NESHAP General
Provisions (40 CFR part 63, subpart A), which are mandatory for all
operators subject to national emissions standards. These recordkeeping
and reporting requirements are specifically authorized by CAA section
114 (42 U.S.C. 7414). All information submitted to the EPA pursuant to
the recordkeeping and reporting requirements for which a claim of
confidentiality is made is safeguarded according to the EPA policies
set forth in 40 CFR part 2, subpart B.
    In addition to the notification, recordkeeping and reporting
requirements in the NESHAP General Provisions, the final rule includes
paperwork requirements associated with initial and 5-year repeat
testing for selected process equipment, electronic reporting of
performance test results, parameter monitoring, preparation of an OM&M
plan, maintenance and inspection of process and control equipment,
compliance with work practice standards and periods of malfunction.
    Collection of data will begin after the effective date of the final
BSCP Manufacturing NESHAP and Clay Ceramics Manufacturing NESHAP. The
compliance date for existing sources is 3 years after the effective
date. The compliance date for new or reconstructed sources is the
effective date if the source startup date is before the effective date,
or upon startup if the startup date is on or after the effective date.
The schedule for notifications and reports required by the rule is
summarized below.
    For BSCP and clay ceramics facilities with existing affected
sources, the initial notification stating that the facility is subject
to the rule must be submitted no later than 120 calendar days after the
effective date of the rule. Facilities with new or reconstructed
affected sources for which startup occurs on or after the effective
date must submit the initial notification no later than 120 calendar
days after the source becomes subject to the rule (although we are
projecting no new affected sources in the short term). Facilities may
choose to submit a request to use the routine control device
maintenance alternative standard no later than 120 calendar days prior
to the compliance date. Facilities required to conduct a performance
test must submit a notification of intent to conduct a performance test
at least 60 calendar days before the performance test is scheduled to
begin. For each initial compliance demonstration that includes a
performance test, facilities must submit an initial notification of
compliance status no later than 60 calendar days following the
completion of the performance test. For each initial compliance
demonstration that does not involve a performance test, facilities must
submit an initial notification within 30 calendar days of completing
the initial compliance demonstration. Records necessary to determine
compliance with the emission limitations and work practice standards
must be compiled on a daily basis, and compliance reports must be
submitted to the Administrator on a semiannual basis. Repeat
performance tests are to be conducted every 5 years to ensure ongoing
compliance.
    There are 90 BSCP facilities that are currently major sources of
HAP, 84 of which have at least one tunnel kiln. An estimated 21 of
these facilities are projected to become synthetic area sources by
promulgation rather than comply with the BSCP standards. The remaining
69 facilities (63 of which have a tunnel kiln) are expected to be
subject to the BSCP Manufacturing NESHAP. For these 69 facilities, the
annual recordkeeping and reporting burden associated with the BSCP
standards (averaged over the first 3 years after the effective date of
the standards) is estimated to be 20,963 labor hours per year, at a
cost of $1,113,105 per year (yr). Burden is defined at 5 CFR 1320.3(b).
    No capital costs associated with monitoring, testing, recordkeeping
or reporting are expected to be incurred during this period. The annual
operation and maintenance costs are estimated to be $682/yr.
    The total burden for the federal government (averaged over the
first 3 years after the effective date of the standards) is estimated
to be 71 labor hours per year, at a total labor cost of $3,698/yr. (All
costs are in 2011 dollars.)
    There are three clay ceramics facilities that are currently major
sources of HAP and are expected to be subject to the Clay Ceramics
Manufacturing NESHAP. For these three facilities, the annual
recordkeeping and reporting burden associated with the Clay Ceramics
standards (averaged over the first 3 years after the effective date of
the standards) is estimated to total 996 labor hours per year at a cost
of $52,674/yr.
    As with the BSCP standards, no capital costs associated with
monitoring, testing, recordkeeping or reporting are expected to be
incurred during this period. The annual operation and maintenance costs
are estimated to be $44/yr.
    The total burden for the federal government (averaged over the
first 3 years after the effective date of the standards) is estimated
to be 4.6 labor hours per year, at a total labor cost of $239/yr. (All
costs are in 2011 dollars.)
    Because BSCP and clay ceramics facilities are not required to come
into full compliance with the standards until 3 years after
promulgation, much of the respondent burden (e.g., performance tests,
inspections, notification of compliance status, compliance reports,
records of compliance data and malfunctions) does not occur until the
fourth year following promulgation.
    For the BSCP Manufacturing NESHAP, we estimate an average annual
recordkeeping and reporting burden of 48,674 labor hours per year, at a
cost of $2,702,447/yr, for years 4 through 6. We also estimate
annualized capital costs of $606,760/yr and annual operating and
maintenance costs of $206,872/yr over this period, for a total
annualized cost of $813,632/yr. The average annual burden for the
federal government for years 4 through 6 is estimated to be 3,891 labor
hours per year, at a total labor cost of $204,550/yr. (All costs are in
2011 dollars.)
    For the Clay Ceramics Manufacturing NESHAP, we estimate an average
annual recordkeeping and reporting burden of 2,323 labor hours per
year, at a cost of $122,786/yr, for years 4 through 6. We also estimate
annualized capital costs of $72,050/yr and annual operating and
maintenance costs of $27,069/yr over this period, for a total
annualized cost of $99,119/yr. The average annual burden for the
federal government for years 4 through 6 is estimated to be 180 labor
hours per year, at a total labor cost of $9,448 per year. (All costs
are in 2011 dollars.)
    An agency may not conduct or sponsor, and a person is not required
to respond to, a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for the
EPA's regulations in 40 CFR are listed in 40 CFR part 9. When OMB
approves this ICR, the agency will announce that approval in the
Federal Register and publish a technical amendment to 40 CFR part 9 to
display the OMB control number for the approved information collection
activities contained in this final rule.

C. Regulatory Flexibility Act (RFA)

    Pursuant to sections 603 and 609(b) of the RFA, the EPA prepared an
IRFA that examines the impact of the proposed rule on small entities
along with regulatory alternatives that could

minimize that impact. The complete IRFA is available for review in the
docket and is summarized here. We convened a SBAR Panel to obtain
advice and recommendations from small entity representatives that
potentially would be subject to the rule's requirements. Summaries of
the IRFA and Panel recommendations are included at 79 FR 75669-75671.
    As required by section 604 of the RFA, the EPA prepared a final
regulatory flexibility analysis (FRFA) for this action. The FRFA
addresses the issues raised by public comments on the IRFA for the
proposed rule. The complete FRFA is included in Section 5 of
``Regulatory Impact Analysis: Final Brick and Structural Clay Products
NESHAP,'' available for review in the docket (Docket ID No. EPA-HQ-OAR-
2013-0291), and is summarized here.
1. Need for the Rule
    The EPA is required under CAA section 112(d) to establish emission
standards for each category or subcategory of major and area sources of
HAP listed for regulation in section 112(b). These standards are
applicable to new or existing sources of HAP and shall require the
maximum degree of emission reduction. In the Administrator's judgment,
the pollutants emitted from BSCP manufacturing facilities cause or
contribute significantly to air pollution that may reasonably be
anticipated to endanger public health. Consequently, NESHAP for the
BSCP source category are being finalized.
2. Objectives and Legal Basis for the Rule
    Section 112(d) of the CAA requires the EPA to set emissions
standards for HAP emitted by major stationary sources based on the
performance of the MACT. The MACT standards for existing sources must
be at least as stringent as the average emissions limitation achieved
by the best performing 12 percent of existing sources (for which the
Administrator has emissions information) or the best performing five
sources for source categories with less than 30 sources (CAA section
112(d)(3)(A) and (B)). For new sources, MACT standards must be at least
as stringent as the control level achieved in practice by the best
controlled similar source (CAA section 112(d)(3)). The EPA also must
consider more stringent ``beyond-the-floor'' control options. When
considering beyond-the-floor options, the EPA must consider not only
the maximum degree of reduction in emissions of HAP, but must take into
account costs, energy and non-air environmental impacts when doing so.
This rule is being proposed to comply with CAA section 112(d).
3. Significant Issues Raised
    The EPA received comments on the proposed standards and requests
for comment that were included based on SBAR Panel recommendations. See
section V of this preamble and ``National Emission Standards for
Hazardous Air Pollutants for Brick and Structural Clay Products
Manufacturing: Background Information for Final Rule--Summary of Public
Comments and Responses'' in Docket ID No. EPA-HQ-OAR-2013-0291 for more
detailed comment summaries and responses.
     Work practices for dioxin/furan: One commenter stated that
work practices for dioxin/furan emissions from BSCP tunnel kilns are
not lawful under the CAA, and, even if they were, the work practices
proposed are not sufficient to minimize dioxin/furan emissions. Other
commenters supported the proposed work practices for dioxin/furan.
    Response: The EPA is finalizing work practices for dioxin/furan as
proposed. The EPA's response to the legal arguments made against work
practice standards is presented in ``National Emission Standards for
Hazardous Air Pollutants for Brick and Structural Clay Products
Manufacturing: Background Information for Final Rule--Summary of Public
Comments and Responses'' found in the docket (Docket ID No. EPA-HQ-OAR-
2013-0291).
     Work practices for Hg and other metals: Several commenters
responded to the EPA's request for comment on work practices for Hg and
non-Hg HAP metals. Numerous commenters stated that the EPA should
finalize work practices instead of numeric limits and provided support
for their assertion that the numeric limits are technically and
economically impracticable to enforce. Commenters also noted that the
emissions reduced by these numeric standards are not justified by the
high cost that would be incurred to meet the standards.
    Response: Emissions of Hg and non-Hg HAP metals were detected using
standard EPA test methods; therefore, the Hg and non-Hg HAP metals data
sets do not meet the criteria for setting work practice standards under
CAA section 112(h). The EPA is finalizing numeric standards for Hg and
non-Hg HAP metals under CAA section rather than work practices. The
final numeric standards have been revised since the proposal to account
for new data from the industry (including data on the Hg content of raw
materials), removal of test data found not to meet the requirements of
the applicable data, and changes in the EPA's approach to selecting the
MACT floor pools (see section V.B.1 of this preamble for additional
details).
     Health-based standard for acid gases: Several commenters
asserted that the EPA may not legally set CAA section 112(d)(4) health-
based standards for acid gases for BSCP facilities. Other commenters
supported the EPA's decision to propose health-based standards for acid
gases but noted that the EPA's approach was overly conservative and
requested that the EPA consider setting multiple limits based on site
characteristics.
    Response: The EPA is finalizing the health-based standards for acid
gases as proposed. The EPA's response to the legal arguments made
against health-based standards is presented in section V.A of this
preamble. The EPA is not changing the HBEL from proposal, as the
proposed HBEL provides low potential for both chronic and acute health
effects.
     Size subcategories for MACT floors: Several commenters
requested that the EPA subcategorize by size for the non-Hg HAP metal/
PM MACT floor limits, as was proposed for Hg.
    Response: As part of recalculating the MACT floor limits based on
the final data set, the EPA is finalizing separate limits for small and
large kilns for non-Hg HAP metals/PM as well as Hg. The EPA is also
finalizing limits in three different formats for both pollutants to
provide additional flexibility for small tunnel kilns and tunnel kilns
with a low metals content in the PM emissions.
     Sawdust dryers: Several commenters requested that the EPA
finalize a subcategory of sawdust-fired kilns venting to sawdust
dryers. Commenters provided general descriptions of how the operation
of these kilns is different than tunnel kilns and stated that there are
only two operating that would be subject to the BSCP Manufacturing
NESHAP.
    Response: Although one commenter noted that stack testing of a
sawdust dryer is being considered, commenters did not provide test data
to demonstrate that emissions from sawdust dryers are different than
other tunnel kilns. Therefore, the EPA is not finalizing a subcategory
of sawdust-fired kilns venting to sawdust dryers.
     Periods of startup and shutdown: One commenter stated that
work practices for periods of startup and shutdown of BSCP tunnel kilns
are not lawful under the CAA. Other commenters supported the proposal
to provide work practices for periods of

startup and shutdown, but suggested improvements to the standards to
make them feasible for all tunnel kilns.
    Response: The EPA evaluated the comments and is finalizing work
practice standards for periods of startup and shutdown that reflect
best practices for minimizing emissions during these periods (see
section V.B.2 of this preamble for additional information).
     MACT floor pool: Several commenters supported the EPA's
proposal to calculate MACT floor standards for PM based on the top 12
percent of the kilns in the industry (i.e., the best-performing sources
with a FF-based APCD). One commenter asserted that the EPA's proposal
is unlawful and the EPA must consider other factors than the APCD type
when setting MACT standards.
    Response: The EPA reviewed all the data used for the MACT floor for
PM as a surrogate for non-Hg HAP metals and found that some of the test
data did not meet the requirements of EPA Method 5. When these data
were removed, the EPA could no longer confirm that the data available
to the agency represented all the best-performing sources. Therefore,
the final PM and non-Hg HAP metals are based on the top 12 percent of
sources for which we had test data, regardless of APCD type (see
section V.B.1 of this preamble for additional details).
4. SBA Comments
    The SBA's Office of Advocacy supported the EPA's proposals to set
work practice standards and health-based emission standards in all
instances allowed by statute and suggested other areas of improvement.
The comments on areas of improvement and the EPA's responses are
summarized below:
     Hg standards: The EPA should pursue subcategorization by
input (raw material) type and delay promulgation of a Hg standard to
gather more information if needed. Standards may need to be combined
with a significantly longer averaging time to allow for continuous
compliance.
    Response: The EPA maintains that a delay in promulgation of an Hg
standard is not appropriate for two reasons. First, under CAA section
112(e), the EPA was scheduled to complete standards for all source
categories by 2000. The EPA's 2003 BSCP Manufacturing NESHAP was
vacated, and that vacatur re-created the EPA's obligation to set
standards for the BSCP source category. Sierra Club v. EPA, 850
F.Supp.2d 300, 303-304 (D.D.C. 2012). Under the consent decree in that
case, as amended in August 2014, the EPA was obligated to sign a notice
of final rulemaking to set standards for the BSCP source category by
September 24, 2015.
    Second, the EPA notes that following proposal, it received
additional information on the Hg content of raw materials from
facilities in the BSCP industry. This information did not provide the
EPA with the information needed to establish subcategories based on the
class or type of raw materials. However, the EPA has concluded that it
has sufficient information to allow it to finalize Hg standards that
account for the variability of Hg content in raw materials. Thus, the
EPA's conclusion is that there is no basis to delay promulgation of the
Hg standards in order to gather more information.
     Economic analysis: The economic impact of the proposed
rule on small entities is significantly underestimated. Specifically,
the EPA should not annualize costs at 7 percent over 20 years because
that does not reflect the financing options available to small