to also reduce a particular HAP, the facility is taking specific
actions that results in a reduction of the pollutant. For example, a
facility that installs a thermal oxidizer to reduce total hydrocarbons
also reduces organic HAP, even though the thermal oxidizer may not have
been installed for purposes of HAP reduction. However, the facility is
still taking a specific action that reduces HAP emissions. Also,
another facility can install a similar control device and expect to
achieve the same result. Results thus can be duplicated from site to
site.
    In the case of cement kilns, the ``actions'' being taken that in
some cases may reduce mercury emissions are the result of site specific
factors that cannot necessarily be duplicated elsewhere. For example,
facility A may achieve lower mercury emissions than facility B simply
because the limestone quarry used by facility A has a lower mercury
content (at least on the day of the respective performance tests).
Facility A is not achieving lower mercury emissions deliberately, but
it is still achieving a lower level. However, because facility B does
not have access to facility A's quarry, it would have to use some other
control technique to match facility A's mercury emissions. The
commenter never disputes that requiring facility B (and quite possibly
A) to match the performance will require installation of a control
device not used in the industry. As explained at proposal and earlier
in the preamble, this amounts to an impermissible de facto beyond-the-
floor standard.
    The commenter also states that the best performing kilns are
achieving lower mercury emission using a variety of methods, but does
not offer any data or analysis as to what these methods are, or how
other facilities could duplicate the performance of the lower emitting
facilities without adding some type of back end controls. In addition,
due to the wide variation in emissions level due to variations in raw
materials, we have no data to show conclusively that even if back end
controls were applied that kilns with higher mercury emissions due to
higher mercury contents in their limestone could achieve the same
emissions levels as facilities with naturally occurring low mercury
limestone used in the (one-time, snapshot) performance test.
    Comment: Regarding EPA's rejection of a beyond-the-floor mercury
standard on the basis of low levels of mercury emissions and high costs
of reducing emissions, one commenter states that the CAA requires that
EPA's standards must reflect the ``maximum degree of reduction that is
achievable'' considering the ``cost of achieving such emission
reduction'' and other enumerated statutory factors. According to the
commenter, the only relevant factors regarding the cost measures are:
(1) Whether it is too costly to be ``achievable''; and (2) whether it
would yield additional reductions, i.e., without the measure, the
standard would not reflect the ``maximum'' achievable degree of
reduction. The commenter states that EPA does not claim that the use of
ACI would not be achievable, only that ACI is not ``justified.'' This
position, according to the commenter, contravenes the CAA and exceeds
EPA's authority and would allow EPA to avoid properly determining the
maximum degree of reduction achievable considering cost and the other
enumerated factors.
    Response: We disagree with the commenter's interpretation.
    The statute requires that EPA consider ``the cost of achieving such
emission reduction'' (section 112 (d)(2)) in determining the maximum
emission reduction achievable. This language does not mandate a
specific method of taking costs into account, as the commenter would
have it, but rather leaves EPA with significant discretion as to how
costs are to be considered. See Husqvarna AB v. EPA, 254 F. 3d 195, 200
(D.C. Cir. 2001). In that case, the court interpreted the requirement
in section 213 (a) (3) of the CAA (which mirrors the language in
section 112(d)(2))that nonroad engines ``achieve the greatest degree of
emission reduction achievable through the application of [available]
technology * * * giving appropriate consideration to the cost of
applying such technology'', and held that this language ``does not
mandate a specific method of cost analysis''. The court therefore
``f[ound] reasonable EPA's choice to consider costs on the per ton of
emissions removed basis''.
    Moreover, where Congress intended that economic achievability be
the means of assessing the reasonableness of costs of technology-based
environmental standards, it says so explicitly. See Clean Water Act
section 301 (b) (2) (A) (direct dischargers of toxic pollutants to
navigable waters must meet standards reflecting ``best available
technology economically achievable'' (emphasis added). There is no such
explicit directive in section 112 (d)(2). EPA accordingly does not
accept the commenter's interpretation.
    Comment: Several comments support EPA's decision not to develop
either an existing or new source floor for mercury. The commenters
state that an achievable floor cannot be developed

because wide variation in mercury concentrations in raw materials and
fuels used by cement kilns would make compliance impossible. One
commenter also agrees with EPA's statement that a national conversion
of cement kilns to natural gas is not possible due to serious supply
problems and the lack of an adequate natural gas infrastructure.
    Response: We agree with these comments that the Agency cannot
establish a floor based on raw material or fuel inputs.
    Comment: One commenter restates its original position that EPA's
arguments regarding its inability to establish floors are irrelevant,
unlawful and arbitrary. The commenter states that evidence made
available since the original comment period closed confirms that: (1)
Some kilns perform better than others; (2) consistent and predictable
differences in emission levels can be attributed to differences in the
raw materials, fuel, kiln design and control technology; and (3)
additional measures for controlling mercury emissions are available to
kilns. The commenter states that there is evidence that: (a) Some kilns
use raw materials that are consistently higher or lower in mercury than
other kilns as evidenced by a cement kiln in Tehachapi, California that
uses limestone from a quarry adjacent to an abandoned mercury mine and
consistently reports high (2000 lb/yr) mercury emissions--other kilns
have consistently lower mercury levels because they use raw materials
with low mercury levels; (b) there are many measures by which mercury
emissions can be reduced as exemplified by Holcim's statement that
mercury emissions can be controlled by careful input control and EPA's
acknowledgement that mercury emissions are affected by the use of
mercury-contaminated fly ash--as only 39 of 112 plants choose to use
fly ash, the commenter states that a plant's deliberate choice about
using fly ash (as well as the choice by some to burn tires, or choosing
to burn a rank of coal lower in mercury, and use of by products from
steel mills and foundries and flue gas dryer sludge) results in
consistent and predictable differences in their mercury emissions; (c)
wet kilns emit more mercury than dry kilns (twice as much according to
EPA), showing that the kiln design results in a consistent and
predictable difference in mercury emissions; and (d) additional
emissions data confirm that some kilns are achieving consistently
better emission levels than others. Several comments were received
regarding the adequacy of the emissions data used in EPA's analyses.
Several commenters state that EPA should collect data on mercury
emissions and then determine mercury limits based on data.
Recommendations for collecting additional data included soliciting test
data from State and local agencies. Several commenters state that EPA
should conduct a new MACT floor and beyond-the-floor evaluation based
on current and complete data--including data from state and local
agencies where cement plants are located--on mercury emissions from
Portland cement plants. According to one commenter, EPA explained that
its decision not to set mercury standards was due to a lack of
emissions data while in reality it chose not to gather data under an
incorrect statutory interpretation that it did not have to set
standards if it believed there was no control technology available. The
commenter states that now EPA has access to more mercury emissions data
than it initially claimed including: (1) Toxic release inventory (TRI)
data based on mercury stack monitoring by 35 plants and, (2) as
indicated by EPA, data on mercury content of coal fly ash, shale, and
clay that is either already available or can be easily obtained from
existing sources--the commenter notes that Florida DEP reports that
kilns collect several samples of the mercury levels in their raw
materials on a daily basis.
    Response: We disagree that our arguments regarding the inability to
establish floors are irrelevant, unlawful and arbitrary. We agree that
some kilns emit less mercury than others in individual performance
tests. The argument that these kilns consistently perform better over
time than other kilns is not correct, however, as shown in section
IV.A.1.a above, where we showed that one of the lowest emitting kilns
in a single test was one of the highest emitting in a later test due to
raw material mercury variability. We thus do not believe it is
appropriate to use the term ``perform better then others'' because this
implies that the emission levels achieved are the result of some
controllable action or otherwise will perform over time at some
predictable level. A facility cannot achieve a performance level
similar to another facility by varying its inputs because, as
previously discussed, one facility does not have access to another's
raw materials (or fuels), and therefore cannot be expected to
necessarily achieve the same mercury emissions levels based on input
control. The commenter acknowledges that facilities have significant
variations in raw materials mercury content.
    The commenter also notes that only some facilities choose to use
fly ash which results in predictable and consistent differences in
mercury emissions. While the statement that only some facilities use
fly ash is correct, there are no data to indicate that the use of fly
ash results in consistent and predictable differences in mercury
emissions. All the raw materials and fuels that enter the kiln affect
mercury emissions. The decision to use fly ash may or may not affect
mercury emissions based on the mercury content of the raw materials the
fly ash replaces. The only way to predict the impact on mercury
emissions of fly ash for the plant currently using this material would
be to obtain long term detailed raw materials and fuel analyses for
every plant, including analyses of the replaced materials. However, in
many cases the replaced materials may no longer be available. Neither
are the data available for the current materials being used. In no way
does the use of fly ash make the mercury emissions any more consistent
than for facilities not using fly ash, or vice versa. All kilns are
still subject to uncontrollable variations in raw materials and fuels,
of which fly ash is only a small part. In fact, the two facilities with
the highest measured mercury emissions do not use fly ash, and one of
these facilities, which happens to have 30 days of feed materials
analyses for mercury, shows significant variations in mercury
emissions. There are no data to support any contention that using fly
ash will inevitably result in a mercury emissions increase at any
specific site.
    The commenter also stated that kiln design--wet versus dry--affects
mercury emissions. There are no data to support that statement, nor are
we aware of any reason a wet or dry kiln would perform differently with
respect to mercury emissions. The information referred to by the
commenter is from the TRI. These data do not differentiate between
kilns that burn hazardous waste, which are a different class of kiln
subject to different regulations, and those that do not. Cement kilns
that burn hazardous waste tend to be wet kilns and also tend to have
higher mercury emission than kilns that do not burn hazardous waste,
because of higher mercury levels in the hazardous waste fuels burned by
these kilns. Therefore, the data cited by the commenter do not support
their conclusion.
    Several commenters also suggested that EPA collect additional
emission test data from State and local agencies. We collected
additional data, and have begun the process of gathering more. See
section IV.A.1.b above, and the separate notice in today's Federal
Register announcing reconsideration of

the new source standard for mercury. We believe data in the record
conclusively show that because of the variations in raw materials
mercury content show that any mercury limit based on these data would
not be achievable on a continuous basis, even by the kilns that form
the basis of the floor, without the requirement of applying beyond-the-
floor back end control technology. The TRI monitoring data referenced
by one commenter is actually short term tests. To our knowledge, there
are no cement kilns using mercury continuous monitors. The data the
commenter referenced from Florida are daily samples, but they are only
analyzed on a monthly basis. In any case, any emission limit based on
these data would not solve the problem that other facilities do not
have access to the same raw materials.
    Comment: In commenting on the adequacy of EPA analysis of the MACT
floor for existing and new sources, several comments were received
recommending that EPA give further consideration to requiring the use
of emission control technology for reducing mercury emissions.
    Several commenters state that EPA's analysis should have considered
wet scrubbers, dry scrubbers, wet absorbent injection, dry absorbent
injection, and fly ash retorting with mercury controls. One commenter
states that in evaluating the MACT floor, EPA should establish a link
between mercury emissions and existing controls for sulfur and
particulate matter and examine potential co-benefit reductions.
According to the commenter, this would be similar to the approach used
by EPA in establishing the initial mercury caps in the Clean Air
Mercury Rule (CAMR). The commenter believes that specific control
equipment will result in a percent reduction of mercury whether the
mercury is from feedstock or from fuel. Standards could be expressed as
a desired percent control achieved using a specific control technology
combination for sulfur and particulate matter as was done in the coal-
fired electric steam generating unit determinations. The commenter
states that such an approach is necessary to determine a new source
standard for Portland cement kilns. The commenter included the tables
that were developed for the percent reduction determination for
electric utilities. One commenter states that more than 60 U.S. and 120
international waste-to-energy plants fueled with municipal or
industrial waste or sewage sludge use sorbent injection ahead of fabric
filters to remove mercury from flue gases. The sorbents used include
activated carbon, lignite coke, sulfur containing chemicals, or
combinations of these compounds. Sorbent injection systems are
demonstrated at the Holcim Dundee plant which is limited by its permit
to 115 lb/yr mercury, most of which is assumed to be from coal. Mercury
limits are also in place under the hazardous waste combustor rule (70
FR 59402): 120 [mu]g/dscm for new or existing cement kilns; 130 [mu]g/
dscm for hazardous waste incinerators; 80 [mu]g/dscm for large
municipal waste combustors. The commenter states that these limits set
a precedent for establishing more stringent mercury emission limits and
that there are abatement technologies available to exceed requirements.
The commenter provided emissions data for several U.S. cement kilns as
well as emissions data from cement kilns operating in Europe. The
commenter states that sorbent injection control technology is proven
for mercury control and states that this technology has been
demonstrated on full-scale demonstrations in the electric generating
sector. According to the commenter, activated carbon is also used to
remove SO2, organic compounds, ammonia, ammonium, HCl,
hydrogen fluoride, and residual dust after an ESP or FF and that the
spent or used sorbent can be used as a fuel in the kiln and the
particles are trapped in the clinker. The commenter notes that a cement
manufacturer in Switzerland, fueled with renewable sludge waste, used
activated carbon to achieve up to 95 percent reduction in
SO2 which correlates to an emission rate of less than 50
[mu]g/m3.
    One commenter states that EPA should also consider pre-combustion
technology for coal that has been demonstrated in the utility sector.
One such technology, pre-combustion coal beneficiation, transforms
relatively low cost, low rank western coal (lignite or subbituminous)
into a cleaner more efficient energy source (k-FuelTM). This
technology applies heat and pressure to reduce moisture and can
increase heat value by 30-55 percent for low rank coals. The result is
higher output per ton of coal while lowering emissions including
reduction in mercury content by up to 70 percent or more and reduced
emissions of SO2 and NOX.
    Response: We have reevaluated the available emission control
technology for reducing mercury emissions. The commenters mentioned
numerous control technologies including wet scrubbers, dry scrubbers,
wet sorbent injection, dry sorbent injection, and fly ash retorting.
Dry sorbent injection and fly ash retorting have not been applied to
cement kilns. Therefore, they cannot be considered the basis of a MACT
floor. Dry scrubbers and wet sorbent injection systems have been
applied at one location each, but these systems do not operate
continuously and would therefore not be considered as a floor
technology. We evaluated the carbon injection system mentioned by the
commenter. However, the configuration of this system is different from
the configuration required to achieve a mercury reduction. The fact
that the facility meets a specific mercury limit is not attributable to
the sorbent injection system, which is configured for control of total
hydrocarbons. (See section IV.C. on why this facility does not
represent new source MACT for THC emissions.)
    We also are aware that wet scrubber technology has been applied to
at least five cement kilns, and therefore we did evaluate wet scrubbers
as a floor technology for both new and existing sources and as a
beyond-the-floor technology for existing sources. Our analysis and
conclusions are set out in sections IV.A.1.d and IV.A.2 above.
    We did not evaluate control technologies other than wet scrubbers
and ACI as a potential beyond-the-floor technology. We have no data to
indicate that these controls are any more efficient or cost effective
than the controls we did evaluate. In addition the performance of these
controls is less certain than either wet scrubbers or ACI.
    The commenter also notes that mercury limits have been applied to
other source categories and to cement kilns that burn hazardous waste.
The application of an emission limit to another source category or
class of cement kiln does not, in and of itself, indicate that a
mercury emissions limit is required or appropriate here. With respect
to the mercury standards for cement kilns that burn hazardous waste, as
noted earlier, these standards are based exclusively on control of
mercury levels in the hazardous waste fuel inputs, and hence are not
applicable to the Portland cement kiln category. See 70 FR 59648. In
addition, we note that the limits mentioned are well above the emission
test data for all but two cement kilns that do not burn hazardous
waste. Cement kilns that burn hazardous waste typically have stack gas
concentrations of 43 to 196 [mu]g/dscm resulting from the hazardous
waste alone (69 FR 21251, April 20, 2004). These levels, which reflect
only the mercury emissions attributable to the hazardous waste, are
themselves higher then the majority of the emission levels from cement
kilns that do not burn hazardous waste, the majority of which are below
43 to 196 [mu]g/dscm. See ``Summary of Mercury Test Data'' in Docket
EPA-HQ-OAR-

2002-0051. Therefore, we believe it is reasonable to assume that cement
kilns that do not fire hazardous waste are much lower emitters of
mercury than the hazardous waste-firing cement kilns.
    The commenter also mentioned pre-combustion technology for mercury
control, including k-Fuel. Coal cleaning is another option for removing
mercury from the fuel prior to combustion. In some states, certain
kinds of coal are commonly cleaned to increase its quality and heating
value. Approximately 77 percent of the eastern and midwestern
bituminous coal shipments are cleaned in order to meet customer
specifications for heating value, ash content and sulfur content. See
Mercury Study Report to Congress: Volume VIII: An Evaluation of Mercury
Control Technologies and Costs, December 1997. Given the fact that most
coal is already cleaned, we believe that any benefits of mercury
reduction from coal cleaning are already being realized. There is only
one k-Fuel production plant of which we are aware, so this fuel is not
available in sufficient quantities to be considered as a potential
alternative fuel. We are not aware of any widely available coals that
have been subjected to more advanced coal cleaning techniques. We also
note that advanced coal cleaning techniques have an estimated cost of
approximately $140 million per ton of mercury reduction. These costs
per ton of removal are higher than costs of other potential beyond-the-
floor technologies such as ACI and wet scrubbers.
    Comment: Several comments were received regarding the need for EPA
to include in its analysis of the MACT floor the use of work practices
alone or in combination with control technologies to reduce mercury
emissions. Two commenters state that the work practice of wasting a
portion of the control device catch, that is disposing of a portion of
the catch rather than recycling it back to the kiln, can reduce total
mercury emissions. One commenter cites a European report showing that
lowering the gas temperature upstream of the baghouse accompanied by
disposing of part of the catch is an effective measure in reducing
mercury emissions. According to the commenter, material removal is
already practiced at many kilns in the U.S. for other reasons than
mercury removal. This occurs for example when CKD is wasted or when a
bypass is used at kilns with preheaters to relieve buildups of volatile
components, e.g., chlorides or sulfates. The commenter states that such
kilns emit less mercury through the stack than kilns that do not waste
CKD. The commenter cites a publication of the PCA documenting this. The
two commenters state that one opportunity to avoid the recycling of CKD
is by mixing it with clinker to make masonry and other types of cement.
One commenter states that CKD has numerous beneficial uses and can be
sold as a byproduct by cement plants. The commenter addresses some of
the barriers to the practice of mixing materials with clinker to make
materials for sale. In response to comments that the industry apply
various non-ACI controls or work practices to reduce mercury emissions,
one commenter states that none of these practices have been
demonstrated to be effective in controlling mercury emissions from
cement kilns.
    One commenter states that EPA could consider prohibiting or
limiting CKD recycling in cement kilns while requiring ACI in
conjunction with existing particulate matter control devices. According
to the commenter, this approach would avoid the expense of an
additional control device and its associated waste stream. The
commenter recognizes that there is a possibility that the mercury and
carbon level in the CKD may cause it to be considered a hazardous
waste.
    Two commenters support the use of alternative feed and fuel
materials as techniques for reducing mercury emissions. One commenter
states that EPA's evaluation of low-mercury fuels should have included
petroleum coke. According to the commenter, testing at one kiln has
shown that petroleum coke contained significantly less mercury than the
coal previously used to fuel the kiln. The commenter also suggested
evaluating the increasing use of tire-derived fuel and its impact on
mercury emissions. One commenter states that data are available that
indicate that mercury content of fuel and feed used by kilns is not so
variable that an upper limit for mercury in coal and feed could not be
set by EPA. One commenter states that EPA should collect sufficient
data on the variability of mercury in feed and fuel materials to
actually determine what the variability is.
    One commenter responded to comments recommending that kilns switch
from coal to petroleum coke, fuel oil, and tire-derived fuel because
these have lower mercury concentrations. The commenter states that
limited supply, long distances, and permitting issues make it
impossible to replace a significant percentage of the coal burned with
alternative fuels. The commenter states, however, that the industry
could utilize a much larger amount of these fuels if permitting
barriers were lowered.
    Response: We agree that reducing the recycling of CKD has, in some
cases, been shown to reduce mercury emissions and that this practice
creates a floor for both existing and new sources. See section IV.A.1.c
above. The amount of CKD recycled versus the CKD wasted at any facility
is based on the concentration of alkali metals in the raw materials.
Also, the effect of this practice on mercury emissions will be highly
variable because the amount of mercury present in the cement kiln dust
varies from facility to facility. Thus, we have adopted a work practice
standard which will reflect these site-specific practices. We also have
evaluated a beyond-the-floor control option based on further reducing
the recycling of CKD back to the cement kiln and determined it was not
achievable (within the meaning of section 112 (d)(2)) after considering
costs, energy impacts, and non-air quality health and environmental
impacts. This would also be the case if one combined ACI and reduced or
eliminated the recycling of CKD.
    One commenter also suggested the use of lower mercury fuels,
specifically petroleum coke, and setting a limit for mercury emission
based on the upper bounds of the limits of mercury in the feed and
fuel. The comment on petroleum coke is addressed above in section
IV.A.1.a.i. We rejected this later option because it would set a limit
that has no environmental benefit because it achieves no emissions
reduction. See section I.A.1.b above. Another commenter mentioned the
problems with setting a limit based on changes to fuels, namely that
limited supply would preclude any MACT floor based on fuel switching,
and would likewise preclude any beyond-the-floor option. We agree with
those comments. See 70 FR 72334.
    Comment: Several comments support EPA's decision not to set
``beyond-the-floor'' mercury standards for the following reasons: (1)
Any possible activated carbon injection ``back-end'' control technology
would be prohibitively expensive; (2) the cost per mass of mercury
emissions reduced would be astronomical; and (3) the application of
such possible activated carbon injection would generate additional
solid waste and increase energy use.
    Response: We agree with these comments for the reasons previously
discussed.
    Comment: A commenter states that in the beyond-the-floor
evaluation, EPA failed to consider other control measures that reduce
mercury emissions. The commenter cited coal cleaning, mercury-specific
coal

treatments, optimization of existing control (the commenter supplied a
list of optimizing technologies), as well as currently available
control technologies such as enhanced wet scrubbing, Powerspan-
ECO[reg], Advanced Hybrid Filter, Airborne Process, LoTox process, and
MerCAP. According to the commenter, mercury reductions for these
technologies range from 20 percent to over 90 percent. According to the
commenter, EPA's failure to evaluate any of these measures is arbitrary
and capricious and contravenes CAA 112(d)(2) which requires the agency
to set standards reflecting the maximum degree of reduction achievable
through the full range of potential reduction measures.
    In a later comment, the same commenter states that EPA failed to
satisfy the CAA by not considering end-of-stack controls. As an example
of a controlled source, the commenter states that Holcim's Zurich plant
successfully uses the Polvitec system, a carbon filter system that
controls mercury as well as organic pollutants.
    One commenter objects to EPA's refusal to set beyond-the-floor
mercury standards as unlawful and arbitrary. The commenter states that
EPA failed to consider eliminating the use of fly ash as a beyond-the-
floor standard even though it is possible for kilns not to use fly
ash--a majority of kilns do not use any fly ash--and not using fly ash
would reduce mercury emissions. For example, the commenter states that
more than half the mercury emissions from an Alpena, MI kiln are from
fly ash. According to the commenter, kilns could also reduce mercury
emissions by using cleaner fuel (e.g., natural gas), using coal with
lower mercury content, refraining from the use of other mercury
containing by-products from power plants, steel mills, and foundries,
and refraining from the use of flue gas dryer sludge. One commenter
recommends that EPA conduct a new beyond-the-floor evaluation based on
up-to-date and complete data.
    Response: We have conducted additional beyond-the-floor analyses
for all demonstrated control techniques for cement kilns. This included
banning use of utility boiler fly ash as feed to cement kilns, reducing
the recycling of CKD, use of wet scrubbers, and use of ACI. The
statement that not using fly ash would reduce mercury emissions is not
supported by existing data, as explained in section IV.A.1.b above.
These are discussed in section I.A.2 above. The commenters mentioned
other additional control techniques including both add-on controls and
coal cleaning. These are not demonstrated control technologies for this
source category. In the case of any coal cleaning technology, we did
not specifically evaluate these technologies. We know of no case where
these technologies have been used in the cement industry, or any other
industry, as the basis for control of mercury emissions, therefore they
cannot be considered a floor technology. We also do not consider these
technologies to be demonstrated to the point where we would consider
them as the basis of a beyond-the-floor standard. As noted above, most
coals are already cleaned. Coals that have been cleaned using advanced
cleaning techniques are not generally available. In addition, data from
an evaluation of advanced coal cleaning indicated that the costs were
approximately $140 million per ton of mercury reduction. See Mercury
Study Report to Congress: Volume VIII: An Evaluation of Mercury Control
Technologies and Costs, December 1997.
    Comment: Citing the information used to estimate costs and mercury
reductions associated with ACI as outdated, unsupported and
unexplained, one commenter states that EPA's estimates are inadequate
and, furthermore, ignores the more recent ACI data used in EPA's power
plant rulemaking.
    Response: We have updated our ACI costs based on more recent
information. As explained above in discussions of potential beyond-the-
floor options based on performance of ACI, we still do not find such
standards to be achievable within the meaning of section 112 (d)(2).
    Comment: One commenter states that recent tests for mercury
emission from Portland cement plants in New York and Michigan show that
EPA does not have an accurate picture of mercury emissions from this
industry. The commenter states that the lack of accurate information
affected EPA's analysis of ACI as a beyond the floor control. The
commenter recommends that EPA conduct additional stack testing to
collect accurate emissions data.
    One commenter also states that EPA does not provide information on
the amount of mercury that would be reduced by ACI. The commenter
states that self-reported mercury emission data provided by industry in
EPA's TRI, appear to grossly underestimate actual kiln mercury
emissions and provides examples of such under-reporting. Based on the
limited emissions test data, the commenter states that actual mercury
emissions data could be ten times greater than the TRI estimates. The
commenter states that EPA's estimate of the cost of ACI and the amount
of mercury that would be reduced are arbitrary and capricious and,
therefore, so is EPA's reliance on cost per ton estimates as a basis
for rejecting ACI as a beyond-the-floor technology.
    Two commenters state that, given mercury's toxicity and the
significant mercury emissions from Portland cement plants, they
strongly disagree with EPA's conclusion that standards to limit mercury
emissions are ``not justified.''
    Response: The commenters did not provide data to support their
claims that mercury emissions from this source category are
significantly underestimated. We are aware that recent tests at several
facilities have indicated that they had significantly underestimated
their mercury emissions. In some cases the mercury emissions were
significantly higher. We are also aware of recent tests where the
measured mercury emissions were low, and in at least one case was
actually below previous estimates. We do not agree that these few cases
indicate that our current estimates of mercury emissions are
significantly in error.
    Comments: Several commenters state that EPA has ignored or
undervalued non-air impacts. Commenters state that EPA should consider
non-air environmental, economic, and societal impacts resulting from
contamination of water bodies and their lost recreational and
commercial fishing uses negatively affecting tourism and jobs; and
neurological effects on children caused by mercury exposures among
females of child-bearing age. According to commenters, local advisories
against eating fish due to mercury tissue levels undercut efforts to
encourage fish consumption as a way to reduce risk of heart disease.
One commenter states that in failing to set maximum degree of reduction
standards that are achievable, EPA did not consider the costs of not
setting mercury standards, including the public health costs of
increased exposure to mercury in children as well as the societal costs
of contaminated water bodies, fish, and other wildlife.
    Response: The purpose of 112(d) standards is to apply maximum
achievable control technology. The consideration of impacts such as
those discussed above is performed during the section 112(f) residual
risk phase. See Sierra Club v. EPA, 353 F. 3d 976, 989-90 (D.C. Cir.
2004) (rejecting the commenter's argument). We have begun this analysis
for this source category. The results of this analysis will be included
in a separate rulemaking.

    Comment: Several commenters raised concerns related to the local
impacts of industrial mercury emissions. According to one commenter,
the high temperature of cement kilns results in mercury emissions that
fall out and are deposited much closer to the source than was
previously thought. One commenter cites research that confirms that
mercury disproportionately affects nearby residents and that shows that
nearly 70 percent of the mercury in an area's rainwater comes from
nearby coal-burning industrial plants. One commenter states that EPA
did not consider impacts of mercury hot spots, citing Florida and EPA
research showing a reduction in local and regional fish mercury levels
when MACT standards for medical and municipal incineration were
implemented. The commenter provided documentation of impacts on local
environments of lowering local or regional mercury emissions. One
commenter states that they are concerned over the documented levels of
mercury in fish in their county and the fact that three recently
permitted Portland cement plants in their county are permitted to emit
over 400 lb/yr of mercury in addition to a coal fired electrical
generating plant that emits over 70 lbs of mercury annually.
    Response: These factors will be considered in the section 112(f)
residual risk analysis discussed above. It is impermissible to consider
these risk-based factors in setting the technology-based standards at
issue here.
    Comment: EPA solicited comments on a potential ban of the use of
mercury-containing fly ash from utility boilers as an additive to
cement kiln feed. Numerous commenters state that a ban is premature for
several reasons, with their objections falling into one of several
groupings: anti-Resource Conservation and Recovery Act (RCRA) policy to
encourage recycling that is protective of human health and the
environment, CAMR in litigation, mercury removal technology not yet
developed, substitutes may be more harmful, and cost of a ban has not
been considered. Due to these concerns about the completeness of data
they believe are relevant to banning the use of fly ash as a cement
plant raw material, the commenters suggest the fly ash ban be postponed
and studied further for now.
    Two commenters add that banning fly ash use, thereby requiring
cement manufacturers to use substitutes for raw materials, cannot be
used as the basis of a national rule due to the variability of mercury
content of fly ash. These commenters also state that banning the use of
fly ash could result in power companies having trouble finding ways to
manage fly ash that would not increase impacts on land use and other
ecosystem values. These commenters state that further study of such
trade-offs is necessary.
    Another commenter notes that approximately 2.5 million tons of fly
ash is used annually in cement kilns, thus reducing the need for an
equivalent amount of natural materials that would come from virgin
sources. Another commenter notes that some configurations of coal-fired
electric generating unit control equipment can reduce the level of ash-
bound mercury, and that research is being conducted on methods that
capture and stabilize mercury, producing a secondary waste product
separate from the ash stream.
    One commenter adds that the costs of replacing fly ash with other
materials could be in excess of $10 million per ton of mercury removed.
This commenter also states that the use of some alternate materials
could result in emissions of HAP, including mercury, and increased
emissions of criteria pollutants either directly or as the result of
increased fuel usage per ton of clinker produced. One commenter agrees
with EPA that fly ash from electric utility boilers may progressively
contain more mercury as the electric utility industry reduces its
mercury emissions. According to the commenter, some boiler fly ash is
of a quality that allows it to be added directly as a raw material for
concrete where most of the mercury is permanently bound; lower quality
fly ash is unusable in concrete and instead is added as a raw material
additive to the cement kiln. This commenter, however, recommends that
EPA consider work practices, monitoring, and mercury controls rather
than a ban on fly ash.
    Two commenters state that data from TRI showing that 64 percent of
kilns not using fly ash account for 60 percent of mercury emissions,
while the 36 percent that do use fly ash account for about 40 percent
of mercury emissions, do not justify a conclusion that fly ash
feedstock from utility boilers that control mercury is a culprit in
mercury emissions from cement kilns.
    Two commenters, citing EPA's positing that wet kilns may emit more
mercury than dry kilns, suggest that the driver for mercury emissions
from kilns may be the type of kiln rather than the feedstock.
    Two commenters note that EPA acknowledges that the proposed ban
fails to consider the solid waste and economic impacts of diverting 2-3
million tons/yr from beneficial use to disposal in landfills, including
the economic impacts of lost revenue from the sale of fly ash, landfill
disposal fees, and the potential rate increases for electricity
consumers; and the environmental impacts of relying on virgin
feedstock--which contains mercury as well as organic compounds--
including increased energy use, additional air emissions, and impacts
on natural resources.
    One commenter states that there are many advantages (a list of the
environmental and energy benefits is included as part of the comment)
associated with the use of fly ash as an alternative for some naturally
occurring raw materials. The commenter states that they also understand
the impacts that the use of fly ash may have on mercury emissions and
are looking at approaches that may be used to minimize mercury
emissions from use of fly ash. They state that they will provide
additional information on a preferred approach should one be
identified.
    One commenter opposes a blanket ban on use of fly ash without
regard to its source or the use of analysis to determine mercury
content. The commenter agrees that setting mercury emission limits is
inappropriate given the variability in concentration in raw materials
and that it would be contrary to case law under CAA section 112. The
commenter lists the manufacturing and environmental benefits of using
fly ash as a substitute for other raw materials: reduced fuel
consumption in kiln; reduced power consumption for grinding; reduce
emissions of organics (THC) and combustion emissions (NOX,
SO2, and CO); reduce need to dispose of fly ash; and reduced
SO2 emissions from reduced use of raw materials containing
pyrites. The commenter states that in some regions, fly ash is the only
source of aluminum for some cement plants. Also, they state that like
other raw materials, the mercury content of fly ash can vary widely.
The commenter recommends an approach that allows the use of fly ash if
companies can demonstrate that mercury emissions will not be
significantly impacted. Such an approach is being developed by the
commenter and will be submitted to EPA as a supplement to their
comments.
    Response: We have considered the comments above and have come to
the conclusion that a ban on the current use of utility boiler fly ash
is not warranted. See section I.A.1.b above.
    Comment: Several commenters are opposed to allowing the use of fly
ash if it means increased mercury emissions. One commenter cited a
study showing that fly ash mercury content can vary from 0.005 to 120
micrograms

per cubic gram of ash as evidence that EPA needs to limit the use of
fly ash in cement and should also evaluate other additives, including
cement kiln dust, for their mercury emissions potential. One commenter
states that if the mercury in fly ash will cause the fly ash to be
classified as a hazardous waste, its use should be banned until the
fate of mercury in the cement manufacturing process is better
understood.
    One commenter states that EPA should take into consideration future
increases in the mercury content of coal combustion products (CCP)
resulting from the Clean Air Interstate Rule and the CAMR. They state
that the higher mercury content of CCP used in producing Portland
cement as well as the recycling of cement kiln dust could cause mercury
emissions to increase.
    Several commenters understand that fly ash is a necessary component
in the manufacturing process, but believe measures should be
implemented to avoid increased mercury emissions. One commenter
recommends the use of fly ash as long as control requirements are
included in the rule, e.g., work practice standards and other
strategies to prevent an increase in mercury emissions from the fly
ash. One commenter states that EPA should require either: (1) Carbon
injection with fabric filtration without insufflation; or (2) treatment
of the ash to remove and capture the mercury. According to the
commenter, if these do not adequately reduce mercury emissions, the fly
ash should not be used. Another commenter states that EPA should
include provisions for pollution prevention plans, in which monitoring
and testing of mercury sources are conducted and appropriate work
practices or other measures are evaluated and implemented to control
mercury emissions. The commenter states that the facility can then
determine the least cost approach for achieving mercury reductions.
    One commenter states that EPA needs to further investigate the
practice of adding fly ash to understand the concentration of mercury
being added and subsequent emissions of mercury. The commenter states
that if alternatives are available, EPA should consider banning the use
of fly ash.
    Response: We received comments both for and against the use of
utility boiler fly ash. As previously noted in this notice, we
performed our own evaluation of the practice based on the available
data. The result of our analysis was that even though we are aware of
one facility where the use of fly ash contributes to approximately half
of the facility's mercury emissions, we cannot state that this occurs
at other cement kilns using fly ash. We also note numerous positive
environmental effects of using fly ash in lieu of shale and clay,
including increases in overall kiln energy efficiency, and a potential
reduction in THC emissions. Given the lack of data that the use of fly
ash adversely affects mercury emissions (i.e. causes an increase in
emissions over raw materials that would be used in place of the fly
ash) other then at one facility, and the other positive environmental
benefits, we do not believe any action is warranted on fly ash use as
currently practiced in the industry.
    The commenters also expressed concern that as utility boilers apply
ACI or other sorbents to reduce their mercury emissions, utility boiler
fly ash will have significantly increased mercury concentrations,
likely well in excess of levels in clay and shale that would be used in
its place. We agree with this concern. As previously noted the
available data indicate that ACI (or other sorbent) can significantly
increase fly ash mercury content. For this reason, we have added a
provision in the final rule to ban the use as a cement kiln feed
utility boiler fly ash whose mercury content has been artificially
increased through the use of sorbent injection, unless it can be shown
that the use of this fly ash will not increase mercury emissions over a
cement kiln's raw material baseline.
    Comment: Regarding EPA's decision to not set HCl standards for
existing kilns, a commenter states that EPA's action is unlawful,
contemptuous of court, and arbitrary for all of the reasons cited above
by the commenter in their comment on EPA's action on the mercury rule.
In addition, the commenter also finds EPA's proposal regarding HCl
unlawful and arbitrary for the following reasons.
    The commenter states that EPA asserts that it ``reexamined'' the
MACT floor for existing sources whereas the court directed EPA to
``set'' HCl standards. Thus, according to the commenter, EPA's stated
reason for not setting HCl standards for existing kilns (the number of
kilns equipped with scrubbers is insufficient to constitute 12 percent
of the kilns) is irrelevant. According to the commenter, the approach
EPA is required to take is to average the emission levels with those of
the other best performing sources to set the floor. The commenter
states that such a level would not reflect the performance of
scrubbers, rather it would reflect the level achieved by the best
performing sources as required by the CAA. The commenter states also
that EPA's reasoning that the unavailability of low-chlorine feed or
fuel justifies a decision not to set HCl standards for existing kilns
is irrelevant, because EPA has an unambiguous legal obligation to set
floors reflecting the HCl emission levels achieved by the relevant best
performing kilns.
    One commenter states that in setting work practice standards for
HCl, EPA did not satisfy the CAA criteria that apply when it is ``not
feasible to prescribe or enforce an emission standard.'' The commenter
states that a work practice standard is unlawful because EPA did not
and could not claim that: (1) HCl cannot be emitted through a
conveyance designed and constructed to emit or capture such pollutant
or that such conveyance would be inconsistent with any existing law; or
(2) the application of measurement methodology is not practicable due
to technological and economic limitations.
    Response: The comment is moot. EPA is not requiring section 112(d)
control of HCl emissions since emissions of this HAP from cement kilns
will remain protective of human health with an ample margin of safety
and will not result in adverse effects on the environment, even under
highly conservative worst case assumptions as to potential exposure.
See section IV.B above, and CAA section 112(d)(4). The court's opinion
does not address the possibility of using the section 112(d)(4)
authority on considering technology-based standards for HCl and EPA's
use of that authority violates nothing in either the letter or spirit
of the court's mandate.
    Comment: Two commenters took issue with EPA's proposed definition
of ``new'' sources as it applies to the proposed HCl limits for new
kilns. Regarding EPA's new source standards for HCl (15 ppmv or 90
percent HCl reduction), one commenter states that EPA has created a
compliance loophole for kilns that commenced construction before
December 2, 2005 and is unlawful. According to the commenter, the CAA
defines new source where construction or reconstruction commenced after
the Administrator ``first'' proposes regulations. The commenter states
that EPA first proposed standards on March 24, 1998, and that any kiln
at which construction or reconstruction was commenced after March 24,
1998, is a new source and must meet new source standards. The commenter
states that EPA ignores that its violation of a clear statutory duty,
(i.e., its failure to promulgate HCl standards in the 1998 rulemaking),
is the reason that sources built after March 24, 1998, have not already
installed

pollution controls necessary to meet new source HCl standards.
    Response: We disagree with these comments. First, the comment is
moot with respect to an HCl new source standard because, based on the
authority of section 112(d)(4), EPA has determined that no such
standard is required because emissions will be at levels which are
protective of human health with an ample margin of safety, and will not
have an adverse effect on the environment. However, the same issue of
the applicability date for new sources is presented for mercury and
THC, so we are responding to the comment.
    The whole premise of new source standards being potentially more
strict than for existing sources, and requiring new sources to comply
immediately with those requirements (see section 112(d)(3) (new source
floor criteria are more stringent than those for existing sources) and
112(i)(1)), is that these sources are being newly constructed and hence
can immediately install the best pollution controls without incurring
the time or the expense of retrofitting. Put another way, new sources
know from the beginning of the construction effort what controls will
be required, and do not have to incur the higher costs and the time-
consuming disruptions normally associated with control retrofits. If we
were to require ``new sources'' that commenced construction prior to
December 2, 2005, to retroactively install controls because we have
changed rule requirements, then these particular sources would have to
bear retrofit costs that we do not believe were intended by the CAA.
Immediate compliance would also be an impossibility.\16\
---------------------------------------------------------------------------

    \16\ As it happens, under this rule, the compliance date for
sources which [0] commenced construction after December 2, 2005, and
before promulgation of this final rule is 3 years because the
standards adopted are more stringent than those proposed on December
2, 2005. See CAA section 112(i)(2). However, the same issue will
arise should EPA adopt revised standards as a result of the periodic
review mandated by section 112(d)(6). There is no indication that
Congress intended the draconian result of sources constructed at the
time of the initial MACT rule (which could be decades in the past
for a section 112 (d)(6) revised standard) to be considered new
sources.
---------------------------------------------------------------------------

    The commenter states that the statute mandates this result because
a new source is defined as a source constructed or reconstructed after
the Administrator ``first proposes'' regulations ``establishing an
emission standard'' applicable to the source. The commenter thus
concludes that the new source trigger date must be March 24, 1998, the
proposal date of the 1999 rule. This reading makes no sense in the
context of a court action which essentially required EPA to reexamine
the entire issue, and re-determine what the standard should be. Under
such circumstances, the only reasonable date for determining new source
applicability for a resulting standard would be the date EPA proposes
it. Moreover, even under the commenter's (strained) reading, EPA did
not propose standards for mercury, hydrocarbons, or HCl for these
sources in the 1998 proposal until December 2, 2005; this is why the
rule was remanded by the D.C. Circuit.\17\ Hence, for the HAP covered
by this rule, the new source trigger date would be December 2, 2005,
even under the commenter's reading. However, we repeat that we disagree
with the commenter's interpretation because it results in situations
antithetical to the underlying premise of a new source standard: namely
that amendments to new source standards will result in existing sources
having to comply immediately with both new source standards and
immediate compliance dates. This would be both unfair and impossible.
Congress simply cannot have intended this result.
---------------------------------------------------------------------------

    \17\ Greenfield cement kilns, for which EPA adopted a new source
standard for THC in 1999, are a separate type of new source for
purposes of this analysis.
---------------------------------------------------------------------------

    Comments: Regarding the proposed work practice standards for
existing kilns (operate at normal operating conditions and operate a
particulate control device), one commenter states that there is not
enough information to require ``normal operating conditions'' for kilns
and air pollution control device. According to the commenter,
``normal'' kiln conditions may not be best for HCl removal. This
commenter also states that existing operating & maintenance (O&M) and
start up, shut down, and malfunction (SSM) plans already ensure normal
operation. Other commenters state that this proposed work practice is
arbitrary as there is no ``normal operating condition'' for all kilns
in the U.S. The commenters state that a multitude of factors--
combustion parameters, kiln design, raw material inputs, fuel
characteristics, etc--make this requirement unworkable.
    One commenter notes that 40 CFR 63.6(e) already requires plants to
minimize emissions during an SSM event to the extent consistent with
good air pollution practices and with safety considerations. The
commenter states EPA should clarify that the proposed requirement to
continuously operate kilns under normal conditions and operate a
particulate control device is subject to the SSM provisions elsewhere
in the NESHAP (section 63.6(e)). The same commenter later submitted
another comment restating their position on HCl that standards for
existing and new kilns are not necessary and do not represent the MACT
floor.
    Response: This comment is also moot given EPA's decision not to set
a section 112(d) standard for HCl based on the authority of section
112(d)(4) of the CAA.
    Comment: One commenter states that EPA has not demonstrated that it
has examined the costs associated with alkaline scrubbers in
establishing a MACT floor for new sources. The commenter states that
EPA's scrubber costs are not representative of a wet scrubber that can
meet limits of up to 90 percent control of SO2. According to
the commenter, EPA's cost are for dry or wet lime spray systems
incapable of 90 percent reduction on preheater/precalciner kilns. The
commenter provides capital and annualized costs for a 1 million tpy
kiln of $18 to $25 million and $4.5 to $7 million, respectively. The
commenter states that using EPA's range of 12 to 200 tpy of HCl
removal, this translates to a cost of between $35,000 and $375,000 per
ton of HCl removed. The commenter states that this range is higher than
the range EPA considered unreasonable for existing kiln beyond-the-
floor controls ($8,500 to $28,000 per ton removed). The commenter
concludes that wet scrubbers are not a reasonable option.
    The commenter adds that dry or wet lime spray systems can remove
SO2 prior to the raw mill but essentially perform the same
function as the raw mill, and therefore achieve an incremental removal
efficiency far below 90 percent. The commenter states that this would
be less cost effective than EPA described for existing kiln beyond-the-
floor technology.
    Response: This comment is also moot in relation to HCl given EPA's
decision not to set a section 112(d) standard for HCl based on the
authority of section 112(d)(4) of the CAA. However, it now has
relevance in regards to the costs of controlling mercury emissions
because we evaluated wet scrubbers for mercury control from existing
sources as a beyond-the-floor option and new sources as a floor option.
We did further investigation of the potential costs of alkaline (wet)
scrubbers and revised our cost estimates after proposal based on data
developed as part of the Industrial Boiler NESHAP. The scrubber costs
are based on alkaline scrubbers specifically designed to remove HCl
and/or SO2 from a coal-fired boiler and we have made the
required adjustments in cost to account for differences in the flue gas

characteristics of a cement kiln versus a coal-fired boiler.
    Comment: One commenter states that EPA's proposed risk-based
exemptions from HCl standards are unlawful, arbitrary and capricious.
On the proposal to develop a single national risk-based HCl standard
based on the RfC for HCl the commenter states no national risk-based
HCl standard exists making it impossible to comment effectively on any
provisions in the cement rule that might rely on a hypothetical future
rulemaking. The commenter continues stating that any attempt to set
risk-based standards on a national rule that does not exist and is not
currently available for review, would contravene the CAA notice and
comment requirements. The commenter states further that 112(d)(4)
allows EPA to set health-based emission standards only for those
pollutants for which a health threshold has been established, and that
no cancer threshold has been set for HCl (nor is there any
classification of HCl with respect to carcinogenicity and none exists).
Also, the commenter states that no non-cancer threshold has been set
for HCl and that the integrated risk information system (IRIS) RfC, on
which EPA attempts to rely, does not purport to be an established
threshold. According to the commenter, disclaimers in IRIS negate any
notion that it provides an established threshold for HCl.
    Response: We largely disagree with these comments. Section 112 of
the CAA includes exceptions to the general statutory requirement to
establish emission standards based on MACT. Of relevance here, section
112(d)(4) effectively allows us to consider risk-based standards for
HAP ``for which a health threshold has been established'' provided
emissions of the HAP are at levels that provide an ``ample margin of
safety.'' Therefore, we believe we have the discretion under section
112(d)(4) to develop standards which may be less stringent than the
corresponding technology-based MACT standards for some categories
emitting threshold pollutants, or not to set a standard if it is
apparent that emissions from the source category (i.e. from any source
in the category, or any potential new source) would remain protective
of human health and the environment with an ample margin of safety and
protective of the environment.
    The data are inadequate to make a determination as to whether HCl
is carcinogenic in either humans or animals, so EPA has not developed
an assessment for carcinogenicity of HCl.
    The IRIS noncancer assessment for HCl provides a RfC for
inhalation. An RfC is an estimate (with uncertainty spanning perhaps an
order of magnitude) of a daily inhalation exposure of the human
population (including sensitive subgroups) that is likely to be without
an appreciable risk of deleterious effects during a lifetime.
    The existence of a threshold for noncancer effects of HCl is
established by general toxicological principles, i.e., that organisms
are able to repair some amount of corrosive tissue damage of the type
caused by HCl. If the damage does not exceed an organisms' ability to
repair it, then no adverse effects will occur. Although the underlying
data for HCl did not identify subthreshold exposures for chronic
effects, this was due to experimental design issues rather than the
absence of a threshold. EPA is unaware of any studies, theory, or
experts that suggest HCl does not have a threshold for adverse effects.
    Comment: Two commenters submitted comments on the need for HCl
standards. According to the commenters, based on a risk analysis using
14 preheat/precalciner kilns at 13 cement plants using a range of in-
stack HCl concentrations as well as a sensitivity analysis using higher
hazardous waste kiln HCl concentrations, risks are well below the
short-term and long-term thresholds. Based on this minimal risk, the
commenters state that there is no need for an HCl standard for new
kilns or the proposed operational standard for existing kilns. The
commenters state that additional data will be submitted to demonstrate
that there is minimal risk and no need for HCl standards.
    As stated in its comments on the original proposal, one commenter
states that a standard for HCl is not warranted for either existing or
new sources. Since the close of the previous comment period, the
commenter conducted a study to evaluate the long term and short term
health risks of HCl emissions from 112 kilns at 67 plants. According to
the commenter, risks were assessed using EPA modeling guidance and
conservative modeling assumptions. The commenter states that based on
their analysis, both chronic and acute risks are below acceptable
levels and that none of the kilns studied have the potential to
generate HCl emissions that result in air concentrations exceeding
EPA's RfC threshold for chronic health effects or Cal EPA's reference
exposure level threshold for acute effects. Based on these results, the
commenter states that there is no justification for an HCl standard for
new or existing cement kilns. The commenter included a copy of the
health risk analysis with their comments. Another commenter refers to
the above information submitted by another commenter that risks to
health from HCl are well below levels acceptable for both chronic and
acute impacts.
    Response: As discussed in section IV.B above, we have reviewed the
risk analysis provided by the commenter and agree that additional
control of HCl is not required.
    Comment: Regarding emission standards for THC, one commenter states
that although EPA has proposed limits, they have not set standards for
the main kiln stack at existing sources and new sources at existing
plants. The commenter states that EPA's position on THC standards is
unlawful, contemptuous of court, and arbitrary for the same reasons
given by the commenter above regarding EPA position on mercury
standards (see above). The same commenter in a later submission, states
that the preamble to the proposed rule appears to indicate that EPA did
not set emission standards for THC emissions from the kiln's main
stack, although the regulatory text does specify emission limits for
the kiln's main stack.
    Response: Since EPA is setting standards for THC (as a surrogate
for non-dioxin organic HAP), and also proposed to do so, this comment
is not factually accurate (and, as noted in earlier responses,
mischaracterizes the court's mandate in any case). In addition, as
previously discussed, we do not agree with the commenter that the
court's mandate required us to set standards regardless of the facts.
The court noted that we had inappropriately limited our analysis to
add-on back end control technologies. As is the case with mercury and
HCl, setting some type of emission limits based on test data would mean
that many facilities would have to apply a beyond-the-floor add-on
control technology to meet the floor level of control without
consideration of the costs, energy, and non-air health and
environmental impacts.
    Comments: One commenter states that EPA has improperly borrowed
standards from its 1999 regulations for hazardous waste combustors,
which were found unlawful and vacated \18\ rather than setting
standards that reflect the THC or CO emission levels actually
achievable by the best performing sources (12 percent of cement kilns
for existing and best performing cement kiln for new). The commenter
states further that although maintaining good combustion

conditions affects THC emissions, it is not the only factor that does
so and cites the plants' selection of raw materials as affecting THC
emissions. The commenter states that EPA's new greenfield source
standard reflects that use of low organic feed materials affects THC
emissions and also cites statements by Florida DEP and Holcim that
selection of feed materials can affect THC emissions. The commenter
states that EPA admits that add-on controls, e.g., ACI and scrubber/RTO
(in use on two kilns), as well as precalciner/no preheater technology
reduce THC emissions. According to the commenter, because these other
factors can affect THC emissions, EPA has incorrectly set the floor
based on good combustion control only. The commenter states that EPA
concedes that cement kilns may be able to achieve better THC emission
levels than through the use of good combustion alone when it discusses
in the proposed rule that nonhazardous waste cement kilns should be
``less challenged'' than hazardous waste kilns in meeting the proposed
limits and that the ``lack of any hazardous waste feed for a non-
hazardous waste (NHW) cement kiln should make it easier to control the
combustion process.'' The commenter states that EPA did not account for
the fact that nonhazardous waste burning kilns can control their
combustion conditions and thus THC emission more easily than hazardous
waste burning kilns, instead just borrowing the standard for hazardous
waste burning kilns without attempting to show that the proposed limits
reflect what is actually achievable by the relevant best performers.
According to the commenter, EPA's arguments that it does not have to
consider factors other than good combustion were rejected by the court
as irrelevant and EPA must set the THC limits reflecting the average
emission level that the best sources actually achieve.
---------------------------------------------------------------------------

    \18\ This is incorrect; the THC rules for hazardous waste
incinerators/cement kilns/lightweight aggregate kilns were not
challenged and were therefore not vacated by the D.C. Circuit. See
CKRC, 255 F.3d at 872.
---------------------------------------------------------------------------

    Response: In the original NESHAP, we noted that THC emissions were
primarily a function of the organic materials in the kiln feed. As we
have previously discussed, a facility has a starkly limited ability to
change their raw materials to reduce their organic content. The fact
that individual facilities have successfully reduced organic contents
of their feed materials to reduce THC emissions does not indicate that
this option is available to all facilities. Therefore, we cannot use
this option as the basis of a national standard for existing
facilities.\19\
---------------------------------------------------------------------------

    \19\ EPA could subcategorize each source based on its raw
material organic content (each source being a different ``type''),
but rejects this alternative as being a paper exercise not producing
environmental benefit.
---------------------------------------------------------------------------

    For new greenfield facilities we established in the 1999 rule that
a facility would have the option to site the quarry at a location with
low enough organic content that they could meet a 50 ppmv THC emissions
limit. We determined that this was feasible because two facilities had
already done so at the time we promulgated the original NESHAP. This
limit was not remanded by the court and is currently in effect.
    As we have previously discussed, we do not agree that the court
decision compels us to set a THC standard that will require some
sources to install a beyond-the-floor control technology under the
guise of a floor standard. These facts have not changed from the
original NESHAP.
    However, at proposal we noted that facilities could control THC
resulting from combustion of fuel.\20\ We explained that the basis of
the MACT floor for cement kilns firing hazardous waste was also good
combustion, and these kilns had established limits for THC as a
quantitative measure of good combustion conditions. Given the fact that
both classes of kilns were using the same method of control, we
proposed to apply the same limits to kilns that did not burn hazardous
waste. We have no data, and none were supplied by the commenter, to
make any judgments about whether or not kilns that do not burn
hazardous waste could actually meet a more stringent standard. Because
the standards are based on complete combustion of the fuel, and because
of the extremely high temperatures in the end of the kiln where the
fuels are introduced (both those that burn hazardous waste and those
that do not), we believe that both types of kilns should achieve
comparable complete destruction of organic materials present in the
fuels under normal operating conditions reflecting good combustion.
Simply because we state that controlling THC emissions from kilns that
do not burn hazardous waste should be less difficult than controlling
emissions from kilns that do burn hazardous waste does not imply that
one type of kiln can achieve a measurably lower THC emission level than
another.
---------------------------------------------------------------------------

    \20\ Fuel organics can be controlled because they are fed into
the hot end of the kiln. Feed materials are fed into the other end
of the kiln and therefore have the opportunity to vaporize and leave
with the exhaust gas before they reach the portions of the kiln
which are hot enough to combust them.
---------------------------------------------------------------------------

    Comments: Several commenters state that it is inappropriate to set
THC floor limits based on a different source category, i.e., HWC.
According to the commenters, at issue is the control of products of
incomplete combustion (PIC) vs. control of hydrocarbons from feed
materials. They state that HWC have the option ceasing to burn
hazardous waste when exceeding the limit (and can do so easily using
automatic waste feed cutoff systems) and that the HWC THC standard only
applies when hazardous waste is being burned.
    Three commenters state that the HWC MACT standards were based on
EPA's RCRA Boiler and Industrial Furnace rules, which in turn were
based on the need to safely manage hazardous waste, a need that is
irrelevant to the facilities covered under the current proposal.
    Response: We agree with this comment and have removed the proposed
quantified limits for existing sources. We have not removed the limit
for new sources because the basis of the new source floor (and
standard) is performance of a RTO (preceded by a scrubber to enable the
RTO to function). Application of an RTO (in series with a scrubber)
would allow new cement kilns to meet a 20 ppmv standard, or to remove
98 percent of incoming organic HAP measured as THC.
    Comment: Three commenters state that EPA has no empirical data
demonstrating that any NHW kiln can achieve the proposed limits on a
continuous basis. One commenter states that bench scale studies
estimated that for varying organic levels, 47 percent of samples would
have resulted in emissions that exceed the 20 ppmv limit.
    Response: We agree with this comment and have removed the proposed
limits for existing sources. We have not removed the limit of new
sources because the basis for the new source floor is now the
performance of a RTO. Application of an RTO would allow the facilities
noted in the comment to meet a 20 ppmv standard.
    Comment: Three commenters state that the contribution to THC/CO
from raw materials outweighs the measure of THC/CO for good combustion
of hazardous waste fuels. Thus, THC and CO are not useful indicators of
good combustion. One commenter notes that available information shows
that it is difficult to correlate HC and HAP emissions. The commenter
further states that several studies show that neither THC nor CO is a
reliable surrogate for good combustion or PIC or HAP emissions.
According to the commenter, HC emissions are a function of: (1) Raw
material organic content; (2) source of fuel and firing location; (3)
temperature profile; (4) oxygen concentration; and (5) type of
manufacturing process. One

commenter states that the high temperatures required for the formation
of cement clinker (>2700F) ensure as complete combustion of fuels as is
possible.
    Response: We agree with the comment that because organic
contributions from processing raw materials is the chief contributor to
measured THC levels (since such emissions are not combusted and hence
are not largely destroyed), having a quantified limit for THC as a
measure of good combustion is not appropriate for existing cement kilns
that do not burn hazardous waste. We disagree with the more general
statements regarding the appropriateness of a THC indicator for organic
HAP, and indeed are continuing to utilize THC as an indicator for new
sources. As noted in the proposal of the original NESHAP, the organic
HAP component of THC emissions varies widely (63 FR 14196). However,
THC emissions do contain organic HAP. Applying MACT to THC emissions
will also control organic HAP, but will be less costly than attempting
to set individual limits for each individual organic HAP (64 FR 31918).
    We also agree with the comment that combustion conditions in the
hot end of the kiln where fuels are fired should assure destruction of
organics (including organic HAP) in the fuel. For this reason, we
adhere to our position at proposal that good combustion conditions in
the cement kiln should assure destruction of organic HAP in fuel and
represents the measure of best performance for reducing emissions of
organic HAP from existing cement kilns. As explained in section I.C
above, we have chosen a different means of expressing good combustion
conditions than the quantified THC limit which we proposed.
    Comment: Three commenters state that it is inappropriate to apply
limits for non-dioxin organic HAP when feed materials have varying
levels of organics, which EPA acknowledges by setting THC limits only
for new greenfield sources (EPA also applied variability of feed/fuel
materials in justifying rules or lack of rules for mercury, HCl and
non-mercury metals). Two commenters add that a Reaction Engineering
study shows that organics emitted from kiln feed is extremely variable
across the country with levels varying by over four orders of
magnitude.
    Response: We agree with these comments and have made appropriate
changes in the final rule to the proposed floor for existing cement
kilns' non-dioxin organic HAP emissions to account for the essentially
uncontrollable variability in organic HAP levels in raw materials.
    Comment: A commenter states that EPA failed to consider the
reduction in THC as part of the beyond-the-floor analysis of ACI.
According to the commenter, organic HAP potentially controlled by ACI
include polychlorinated biphenyls, polycyclic organic matter, and
polyaromatic hydrocarbons. According to the commenter, to determine the
maximum degree of reduction in THC emissions that is achievable for
cement kilns, the CAA requires that EPA evaluate the reductions
achievable through the use of ACI.
    One commenter states that: (1) EPA did not determine, as required
by the CAA for beyond-the-floor standards, the maximum degree of
reduction in THC emissions achievable through GCP; (2) EPA did not show
that its standards reflect the maximum degree of reduction achievable
through combustion controls in light of its findings that NHW burning
kilns should be able to achieve the THC standards more easily than
hazardous waste burning kilns; (3) EPA did not determine the maximum
degree of reduction achievable through the judicious selection of raw
materials although they acknowledge that such methods will control THC
emissions and that kilns are already using it and can control THC
emissions through the use of other materials such as fly ash and kilns
can and do import raw materials from sources that are not co-located or
immediately nearby; (4) EPA did not determine the degree of reduction
achievable through the use of end-of-stack controls already in use in
the cement industry, including ACI, which EPA only considered for
mercury and dioxin control and which would reduce THC emissions
significantly and also reduce mercury and dioxin emissions; \21\ (5)
EPA failed to determine the maximum degree of reduction achievable
through the use of limestone scrubber/RTO even though the agency is
aware that such devices can significantly reduce emissions of THC (as
well as HCl) and are already in use in the industry and does not
contend that they are too expensive; and (6) EPA failed to consider or
determine the maximum degree of reduction achievable through the use of
a carbon coke filter system such as the Polvitec system in use at
Holcim's Zurich plant. For the reasons (1-7) listed above, the
commenter states that EPA's beyond-the-floor analysis for THC
contravenes CAA 112(d)(2) which requires that EPA's final standards
reflect the maximum degree of reduction achievable through any and all
reduction measures, and any claim that EPA's THC standard reflects the
maximum achievable degree of reduction would be arbitrary and
capricious in light of EPA's failure to consider these technologies or
explain its decision not to base beyond-the-floor standards on any or
all of them.
---------------------------------------------------------------------------

    \21\ Since the rule already contains a standard for dioxin,
incremental reductions attributable to use of ACI are quite small;
see section IV.a.2 above.
---------------------------------------------------------------------------

    Response: We have no actual test data to establish the impact of
ACI on THC emissions, but are using a figure of 50 percent, which
reflects the best estimates of the one facility using ACI for organics
control. As explained in section IV.C above, the facility in question
is extremely unusual in that the uncontrolled THC emission levels are
much higher than any other facility in the source category, so the 50
percent reduction figure is probably more efficient than would be
achieved industry-wide. As explained in section IV.A.2 above, however,
even assuming this degree of reduction, we did not find a beyond-the-
floor option based on performance of ACI to be achievable within the
meaning of section 112(d)(2).
    The commenter also stated that we did not assess the maximum degree
of THC reduction achievable by optimized combustion practices. There
are no data available to perform this type of analysis and none were
provided by the commenter. Moreover, THC levels significantly below
those associated with good combustion conditions are not necessarily
indicative of further organic HAP reductions. See discussion at 70 FR
59462-59463 (October 12, 2005).
    We also did not evaluate the degree to which ``judicious
selection'' of raw materials can be used to reduce THC emissions,
except that we have previously established that a greenfield facility
can limit THC emission to 50 ppmv by selection of limestone with
sufficiently low organic materials contents. We are aware that cement
production facilities can import some raw materials from sources other
than those nearby. However, the fact that in some cases materials can
be imported from a farther distance does not change the fact that each
individual cement facility has specific raw materials needs based on
their particular limestone and other raw materials. We do not have
data, nor are data available, to develop a national rule that would
cover every possible raw material substitution to reduce THC emissions.
    The commenter also stated we did not assess the maximum degree of
emission

reduction achievable through the use of end-of-stack controls. However,
as previously discussed, there are no data available for us to perform
this analysis for any controls other than an RTO. In the case of an
RTO, we have evaluated its performance as a beyond-the-floor control
for existing sources. In that case, we determined requiring a facility
to apply an RTO as a beyond-the-floor option was not achievable, within
the meaning of section 112(d)(2), due to the high costs and adverse
energy utilization impacts. The new source standard for THC is based on
performance of an RTO (in tandem with a scrubber), as discussed
previously. We do not believe any further control is technically
feasible.
    The commenter also stated we had not considered the use of a carbon
coke system. The source for this comment notes that there was one
facility in Europe. We note the plant in question was designed to burn
pelletized sewage sludge. The source of the comment does not indicate
the performance or costs of this system. We assume it would perform
similarly to a carbon adsorption system, which achieves emission
reductions similar to those of an RTO. We believe that the wet
scrubber/RTO system, which is demonstrated on a cement kiln in the
United States, is a viable beyond-the-floor option. Given the lack of
demonstration of a carbon coke filter in this country, the fact that we
have a viable alternative as a beyond-the-floor option (an RTO), and
the fact that the carbon coke filter is unlikely to perform any better
than an RTO, we do not believe consideration of a carbon coke filter is
warranted.
    Comment: Several commenters oppose EPA's proposed regulation of
area sources for THC. Three commenters state that there is no legal
basis for regulating area sources. The commenters note that there is no
``statement of basis and purpose'' as required by CAA 307(d)(3).
    One commenter recommends that EPA exempt area sources, which would
experience the same cost as major sources with fewer benefits; or
consider less stringent options, e.g., periodic stack test rather than
CEM.
    Response: As previously noted, in the original 1999 NESHAP for this
source category we regulated THC emissions from area sources because
the THC emissions from a cement kiln are likely to contain polycyclic
organic matter. This pollutant is listed in section 112(c)(6) of the
CAA as a pollutant. The commenter provided no data that would lead us
to change this determination (63 FR 14193-94).
    We also considered requiring periodic stack tests rather then THC
CEM. However, the current rule already requires kilns at greenfield
area sources to install a THC CEM. We could see no justification for
allowing a more lenient THC monitoring option for new kilns at non-
greenfield facilities.
    Comment: One commenter states that the requirement for THC CEM will
impose additional cost for no benefit. The commenter recommends that
EPA eliminate numerical limits or require less costly monitoring
options, e.g., periodic stack testing. The commenter recommends that if
EPA does require CEM, extend the compliance date to at least 2 years
because the State certification process requires more than 1 year.
    Response: We have not adopted a requirement that existing sources
install a THC monitor. For new sources, the compliance date is
ordinarily the effective date of the rule or startup, whichever is
later. See section 112(i)(1). However, in this case, because the new
source standard is more stringent than proposed (see discussion in
section IV.C.3 above), sources which commenced construction or
reconstruction after December 2, 2005, but before December 20, 2006,
will have until December 21, 2009 to comply. See section 112(i)(2).
    Comment: Two commenters favor including all crushers in the
Portland cement NESHAP and establishing emission limits for crushers
based on the requirements in 40 CFR, subpart OOO, if they satisfy the
requirements of the CAA. One commenter cites State requirements for
primary crushers of 10 percent opacity, work practices, and a baghouse
with outlet concentration of 0.01 grams per dry standard cubic feet;
secondary crushers are subject to a 20 percent opacity limit. The
commenter provided a copy of their State requirements for crushers at
cement manufacturing facilities.
    One commenter states that applicability based on location relevant
to other sources is confusing and recommended that EPA put all
appropriate requirements for the sources in one requirement and remove
63.1340(c) altogether.
    Response: We agree that applicability based on location relevant to
other sources is confusing. However, in our final determination on this
issue we decided that crushers should not be covered under this NESHAP.
The reasons are first, we have no definitive information that there are
any facilities that currently have crushers after raw materials
storage. Second, we have no data to set a floor for existing crushers
that might potentially be covered. We considered using the current
Nonmetallic Mineral NSPS, which established standards of performance
for new crushers. But we have no data to determine if the NSPS for this
source category would be an appropriate MACT floor. Finally, we believe
we can resolve the issue by simply stating that crushers are not
covered by this regulation. It was never our intent that this rule
regulate equipment typically associated with another source category.
    Comment: One commenter states that all of the raw material handling
and storage, except crushing, should be covered by the Portland cement
NESHAP. They state that the only non-metallic mining activities subject
to the NSPS subpart OOO are at the quarry and at the crusher. The
commenter states that under the alternative interpretation offered by
EPA, several steps characteristic of cement manufacturing would not be
included in subpart LLL, for example the ``on-line'' measurement
devices such as cross-belt neutron analyzers that are used in the
preblending and proportioning steps. The commenter states further that
the raw mix fed to the raw mill is the product of the very careful
instrumentally-aided proportioning and blending operation that is one
of the most important series of steps in the cement manufacturing
process.
    Response: We agree with this comment.

VII. Summary of Environmental, Energy, and Economic Impacts

A. What facilities are affected by the final amendments?

    We estimate that there are approximately 94 cement plants currently
in operation. These 94 plants have a total of 158 NHW cement kilns. We
estimate that 20 new kilns with a capacity of 20,900,000 tpy of clinker
capacity will be subject to the final amendments by the end of the
fifth year after promulgation of the amendments. Note that national
impacts are based on the estimated capacity increase, not on a specific
number of model kilns.

B. What are the air quality impacts?

    For existing kilns, we estimate that the impacts of the amendments
will essentially be zero because we believe that all existing kilns are
already performing the work practices prescribed in the amendments. For
the 20 new kilns the variation in mercury and hydrocarbon emissions
from kilns makes it difficult to quantify impacts on a national basis
with any accuracy.

    For mercury emissions we estimate a new kiln with a capacity of
650,000 typ of clinker will have an emission reduction ranging from
zero to 280 lb/yr. We estimate the national mercury emissions reduction
to be 1300 to 3000 lb/yr in the fifth year after promulgation.
    Reported hydrocarbon emission test results range from less than 1
ppmv dry basis (at 7 percent oxygen) to over 140 ppmv dry basis (Docket
A-92-53) measured at the main kiln stack. For 52 kilns tested for
hydrocarbon emissions (Docket A-92-53), approximately 25 percent had
emissions of hydrocarbons that exceeded the 20 ppmv THC limit at the
main stack. The average hydrocarbon emissions for the kilns exceeding
20 ppmv was 62.5 ppmv. Assuming that most new kilns will be sited at
existing locations this would imply that 15 out of 20 new kilns will
have no THC emissions reduction as a result of the THC Standard. For a
new kiln that, in the absence of the standard, would emit near the
average hydrocarbon level of 62.5 ppmv, the application of new source
MACT consisting of an RTO would result in a reduction of about 196 tpy
for a 650,000 tpy kiln. We also estimate that for 15 percent of the new
kiln capacity will have uncontrolled emissions that exceed the 20 ppmv
limit, but will use alternatives to application of an RTO (such as ACI)
to meet the THC emissions limit. These kilns will achieve an emissions
reduction of approximately 103 tpy for a new 650,000 tpy new kiln. The
total national reduction will be 1100 tpy in the fifth year after
promulgation of the standard.
    The THC and mercury standards for new sources will also result in
concurrent control of SO2 emissions. For kilns that elect to
use an RTO to comply with the THC emissions limit it is necessary to
install an alkaline scrubber upstream of the RTO to control acid gas
and to provide additional control of PM. We estimate that approximately
25 percent of the additional capacity built in the next five years will
have to install wet scrubbers for mercury control, and 10 percent will
install a wet scrubber/RTO system for THC control. The SO2
emissions reductions for a new 650,000 tpy kiln will be approximately
320 tpy, and is estimated as 3640 nationally.
    Note that we have determined that reducing SO2 emissions
also results in a reduction in secondary formation of fine PM because
some SO2 is converted to sulfates in the atmosphere.
Therefore, the THC standards will also result in a reduction in
emissions of fine PM.
    In addition to the direct air emissions impacts, there will be
secondary air impacts that result in the increased electrical demand
generated by new sources' control equipment. These emissions will be an
increase in emissions of pollutants from utility boilers that supply
electricity to the Portland cement facilities. Assuming two new kilns
will install a scrubber followed by an RTO, three will install an ACI
system, and five will install wet scrubbers, we estimate these
increases to be 105 tpy of NOX, 47 tpy of CO, 157 tpy of
SO2, and 5 tpy of PM at the end of the fifth year after
promulgation.

C. What are the water quality impacts?

    There should be no water quality impacts for the proposed
amendments. The requirement for new sources to use alkaline scrubbers
upstream of the RTO will produce a scrubber slurry liquid waste stream.
However, we are assuming the scrubber slurry produced will be dewatered
and disposed of as solid waste. Water from the dewatering process will
be recycled back to the sc in the form of aqueous discharges, addition
of a scrubber will increase water usage by about 41 million gallons per
year (gyps) for each new 650,000 tpy kiln that installs a scrubber, or
a national total of 460 million gyps.

D. What are the solid waste impacts?

    The solid waste impact will be the generation of scrubber slurry
that is assumed to be dewatered and disposed of as solid waste, and
solid waste from the ACI systems. The amount of solid waste produced is
estimated as 519,300 tpy in the fifth year after promulgation of the
amendments.

E. What are the energy impacts?

    Requiring new kilns to install and operate alkaline scrubbers and
RTO will result in increased energy use due to the electrical
requirements for the scrubber and increased fan pressure drops, and
natural gas to fuel the RTO. We estimate the additional electrical
demand to be 41 million kWhr per year and the natural gas use to be 271
billion cubic feet by the end of the fifth year.

F. What are the cost impacts?

    The final rule amendments should impose minimal costs on existing
sources. These costs will be recordkeeping costs to document CKD
wastage. The costs for new sources include the THC monitor and
recordkeeping costs for CKD wastage on all new kilns, a wet scrubber
for mercury control on five new kilns, and a wet scrubber/RTO on two of
the new kilns. The estimated capital cost for a new 650,000 tpy kiln to
install a THC monitor is $140,000, to install a wet scrubber is $2.7
million, and to install a wet scrubber/RTO is $10.7 million. For kilns
where the uncontrolled THC emissions are below 40 ppmv, we are assuming
they will opt for a lower cost THC control, such as ACI. The estimated
capital cost for ACI applied to a new 650,000 tpy kiln is $1.0 to $1.6
million. The total estimated national capital cost at the end of the
fifth year after promulgation is $64 to $67 million.
    The estimated annualized cost per new 650,000 tpy kiln is an
estimated as $34,000 to $37,000 for kilns a THC monitor, $470,000 to
$597,000 for ACI, $1.4 to $1.5 million for a wet scrubber, and $3.6 to
$3.9 million for a wet scrubber/RTO. National annualized costs by the
end of the fifth year will be an estimated $26 to $28 million.

G. What are the economic impacts?

    EPA conducted an economic analysis of the amendments to the NESHAP
which have cost implications. For existing sources the only requirement
with any cost implication is the requirement to keep records of CKD
wastage. These costs are very small. We assessed earlier Portland
cement regulations with greater per source costs, and those costs did
not have a significant effect on the cost of goods produced. Since the
conditions that produced those conclusions still exist today, EPA
believes these new regulations will not have a discernible impact on
the Portland cement market for existing sources.
    For new sources, both the magnitude of control costs needed to
comply with the final amendments and the distribution of these costs
among affected facilities have a role in determining how the market
will change. The final amendments will require all new kilns
constructed on or after December 2, 2005, to install THC monitors. As
with existing sources, the cost on a THC monitor is not significant
compared to the costs assessed in the earlier regulations. However, the
cost for ACI or for the wet scrubbers/RTO systems are significant. We
estimate that 3 of the 20 new kilns will have to install ACI, 2 of 20
new kilns will be required to install a wet scrubber/RTO system to meet
the limits for THC, and five kilns will install a wet scrubber to meet
the new source mercury limits.
    Because of the high cost of transportation compared to the value of
Portland cement, the market for Portland cement is localized and
characterized by imperfect competition. The possible outcomes of the
final amendments are either a deferral in

bringing the new kiln into production or a price increase in the
immediate region around the two new kilns that face control costs. For
perfect competition, control costs at a new facility will be completely
passed on in the long run to the purchaser of the good. With imperfect
competition the outcome is harder to predict. Less than full cost pass
through is a likely possibility.
    The model new kilns used in this analysis have a clinker capacity
of 650,000 tons/yr. The annual control cost would be up to $597,000 for
kilns that apply ACI, $1.5 million for a kiln that applies a wet
scrubber, and $3.9 million for a kiln that applies an scrubber/RTO, in
2002 dollars. Clinker is an intermediate good in the production of
Portland cement and corresponds to a Portland cement capacity of
720,000 tons/yr. To compare the costs to the value of the Portland
cement in 2004 of $85 for a national average mill value we use the
Chemical Engineering Plant Cost Index for 2004 and 2002 to get a 2004
annual cost of $640,000 for kilns that require ACI, $1.7 million for
kiln that apply wet scrubbers, and $4.4 million for those that apply an
scrubber/RTO. The value of the Portland cement produced in a year at
the $85 price would be $61 million. If the cost were to be fully passed
on to the purchaser in a higher price the price would increase by 1.0
to 7.2 percent, to values of $86 to $91, respectively.
    With the increasing demand for Portland cement and the high
capacity utilization of existing plants and the nature of the regional
markets, it is unlikely that the new kilns would be delayed. Because of
the imperfect competition, it is likely in the regions around the two
new kilns facing control, the price of the Portland cement would
increase but by less than the 1.0 to 7.2 percent that would be required
to fully cover the control costs.

VIII. Statutory and Executive Order Reviews

A. Executive Order 12866, Regulatory Planning and Review

    Under Executive Order (EO) 12866 (58 FR 51735, October 4, 1993),
this action is a ``significant regulatory action'' because it raised
novel legal and policy issues. Accordingly, EPA submitted this action
to the Office of Management and Budget (OMB) for review under EO 12866
and any changes made in response to OMB recommendations have been
documented in the docket for this action.

B. Paperwork Reduction Act

    The information collection requirements in this final rule have
been submitted for approval to the OMB under the Paperwork Reduction
Act, 44 U.S.C. 3501 et seq. The information collection requirements are
not enforceable until OMB approves them.
    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 emission standards. These recordkeeping
and reporting requirements are specifically authorized by section 114
of the CAA (42 U.S.C. 7414). All information submitted to EPA pursuant
to the recordkeeping and reporting requirements for which a claim of
confidentiality is made is safeguarded according to Agency policies set
forth in 40 CFR part 2, subpart B.
    These requirements include records of CKD removal from the kiln
system at all existing and new sources, and requirements for new kilns
constructed after December 2, 2005, to install and test a continuous
monitor to measure THC. We expect these additional requirements to
affect 94 facilities over the first 3 years. The estimated annual
average burden is outlined below.

----------------------------------------------------------------------------------------------------------------
                                                                                Total annual
                 Affected entity                    Total hours     Labor costs      O&M costs      Total costs
----------------------------------------------------------------------------------------------------------------
Industry........................................           4,159        $679,105        $161,672        $840,777
Implementing Agency.............................             213          16,100              NA          16,100
----------------------------------------------------------------------------------------------------------------

    Burden means the total time, effort, or financial resources
expended by persons to generate, maintain, retain, or disclose or
provide information to or for a Federal agency. This includes the time
needed to review instructions; develop, acquire, install, and utilize
technology and systems for the purposes of collecting, validating, and
verifying information, processing and maintaining information, and
disclosing and providing information; adjust the existing ways to
comply with any previously applicable instructions and requirements;
train personnel to be able to respond to a collection of information;
search data sources; complete and review the collection of information;
and transmit or otherwise disclose the information.
    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 EPA's
regulations in 40 CFR are listed in 40 CFR part 9. When this
information collection request is approved by OMB, the Agency will
publish a technical amendment to 40 CFR part 9 in the Federal Register
to display the OMB control number for the approved information
collection requirements contained in this final rule.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency
to prepare a regulatory flexibility analysis of any rule subject to
notice and comment rulemaking requirements under the Administrative
Procedure Act or any other statute unless the agency certifies that the
rule will not have a significant economic impact on a substantial
number of small entities. Small entities include small businesses,
small organizations, and small governmental jurisdictions.
    For purposes of assessing the impact of today's proposed rule
amendments on small entities, small entity is defined as: (1) A small
business as defined by the Small Business Administration's (SBA)
regulations at 13 CFR 121.201; (2) a small governmental jurisdiction
that is a government of a city, county, town, school district or
special district with a population of less than 50,000; and (3) a small
organization that is any not-for-profit enterprise which is
independently owned and operated and is not dominant in its field.
    After considering the economic impacts of this final rule
amendments on small entities, I certify that this action will not have
a significant economic impact on a substantial number of small
entities. The small entities directly regulated by the final rule
amendments are small businesses. We determined there are 6 or 7 small
businesses in this industry out of a total of 44. Each small business
operates a single plant with one or more kilns. The total annualized
cost of the standards in the amendments for an existing kiln is

nominal. The revenue for the entire small business sector is estimated
to be around $260 million (2003 dollars). New sources, will incur
higher costs because new kilns must install a THC monitor, and
approximately three of the 20 new kilns will have to install ACI, two
will have to install wet scrubbers, and two will have to install a wet
scrubber/RTO system for THC control. For new sources that must install
controls, the cost of control is estimated to be one to seven percent
of the expected revenue from a new kiln. We currently do not have any
information on plans for small businesses to build new kilns.
    Although the final rule amendments will not have a significant
economic impact on a substantial number of small entities, EPA
nonetheless has tried to reduce the impact of the final amendments on
small entities. The emission standards are representative of the floor
level of emissions control, which is the minimum level of control
allowed under CAA. Further, the costs of required performance testing
and monitoring for non-dioxin organic HAP emissions from new sources
have been minimized by specifying emissions limits and monitoring
parameters in terms a surrogate for organic HAP emissions, which
surrogate (THC) is less costly to measure.

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and tribal
governments and the private sector. Under section 202 of the UMRA, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with ``Federal mandates'' that
may result in expenditures to State, local, and tribal governments, in
the aggregate, or to the private sector, of $100 million or more in any
1 year. Before promulgating a rule for which a written statement is
needed, section 205 of the UMRA generally requires EPA to identify and
consider a reasonable number of regulatory alternatives and adopt the
least costly, most cost-effective, or least burdensome alternative that
achieves the objectives of the rule. The provisions of section 205 do
not apply when they are inconsistent with applicable law. Moreover,
section 205 allows EPA to adopt an alternative other than the least
costly, most cost-effective, or least burdensome alternative if the
Administrator publishes with the final rule an explanation why that
alternative was not adopted. Before EPA establishes any regulatory
requirements that may significantly or uniquely affect small
governments, including tribal governments, it must have developed under
section 203 of the UMRA a small government agency plan. The plan must
provide for notifying potentially affected small governments, enabling
officials of affected small governments to have meaningful and timely
input in the development of EPA regulatory proposals with significant
Federal intergovernmental mandates, and informing, educating, and
advising small governments on compliance with the regulatory
requirements.
    EPA has determined that the final rule amendments do not contain a
Federal mandate that may result in expenditures of $100 million or more
for State, local, and tribal governments, in the aggregate, or the
private sector in any 1 year, nor do the amendments significantly or
uniquely impact small governments, because they contain no requirements
that apply to such governments or impose obligations upon them. Thus,
these final rule amendments are not subject to the requirements of
sections 202 and 205 of the UMRA.

E. Executive Order 13132, Federalism

    Executive Order 13132 (64 FR 43255, August 10, 1999), requires EPA
to develop an accountable process to ensure ``meaningful and timely
input by State and local officials in the development of regulatory
policies that have federalism implications.'' ``Policies that have
federalism implications'' is defined in the Executive Order to include
regulations that have ``substantial direct effects on the States, on
the relationship between the national government and the States, or on
the distribution of power and responsibilities among the various levels
of government.''
    The final rule amendments do not have federalism implications. The
final rule amendments will not have substantial direct effects on the
States, on the relationship between the national government and the
States, or on the distribution of power and responsibilities among the
various levels of government, as specified in Executive Order 13132,
because State and local governments do not own or operate any sources
that would be subject to the proposed rule amendments. Thus, Executive
Order 13132 does not apply to the final rule amendments.

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

    Executive Order 13175 entitled ``Consultation and Coordination with
Indian Tribal Governments'' (65 FR 67249, November 9, 2000), requires
EPA to develop an accountable process to ensure ``meaningful and timely
input by tribal officials in the development of regulatory policies
that have tribal implications.'' The final rule amendments do not have
tribal implications, as specified in Executive Order 13175, because
tribal governments do not own or operate any sources subject to today's
action. Thus, Executive Order 13175 does not apply to the proposed rule
amendments.

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

    Executive Order 13045 (62 FR 19885, April 23, 1997) applies to any
rule that: (1) Is determined to be ``economically significant'' as
defined under Executive Order 12866, and (2) concerns an environmental
health or safety risk that EPA has reason to believe may have a
disproportionate effect on children. If the regulatory action meets
both criteria, the Agency must evaluate the environmental health or
safety effects of the planned rule on children, and explain why the
planned regulation is preferable to other potentially effective and
reasonably feasible alternatives considered by the Agency.
    EPA interprets Executive Order 13045 as applying only to those
regulatory actions that are based on health or safety risks, such that
the analysis required under section 5-501 of the Executive Order has
the potential to influence the rule. The final rule amendments are not
subject to Executive Order 13045 because they are based on technology
performance and not on health or safety risks.

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

    This rule is not a ``significant energy action'' as defined in
Executive Order 13211, ``Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 28355
(May 22, 2001)) because it is not likely to have a significant adverse
effect on the supply, distribution, or use of energy. These rule
requirements will have energy effects due to the energy requirements
for the control devices required for new sources. We estimate the
additional electrical demand to be 15 million kWhr per year and the

natural gas use to be 270 billion cubic feet by the end of the fifth
year. We do not consider these energy impacts to be significant.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement
Act (NTTAA) of 1995 (Pub. L. 104-113, Section 12(d), 15 U.S.C. 272
note) directs EPA to use voluntary consensus standards (VCS) in its
regulatory activities, unless to do so would be inconsistent with
applicable law or otherwise impractical. The VCS are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
VCS bodies. The NTTAA directs EPA to provide Congress, through OMB,
explanations when the Agency does not use available and applicable VCS.
    This final rule involves technical standards. EPA cites EPA Method
29 of 40 CFR part 60 for measurement of mercury emissions in stack
gases for new cement kilns.
    Consistent with the NTTAA, EPA conducted searches to identify
voluntary consensus standards in addition to these EPA methods. The
search and review results are in the docket for this rule.
    One voluntary consensus standard was identified as an acceptable
alternative to an EPA test method for the purposes of the final rule.
The voluntary consensus standard ASTM D6784-02, ``Standard Test Method
for Elemental, Oxidized, Particle-Bound and Total Mercury Gas Generated
from Coal-Fired Stationary Sources (Ontario Hydro Method),'' is an
acceptable alternative to EPA Method 29 (portion for mercury only) as a
method for measuring mercury.
    The search for emissions measurement procedures identified two
other voluntary consensus standards. EPA determined that these two
standards identified for measuring emissions of the HAP or surrogates
subject to emission standards in this rule were impractical
alternatives to EPA test methods for the purposes of this rule.
Therefore, EPA does not intend to adopt these standards for this
purpose. The reasons for the determinations for the two methods are
discussed below.
    The voluntary consensus standard EN 13211:2001, ``Air Quality--
Stationary Source Emissions--Determination of the Concentration of
Total Mercury,'' is not acceptable as an alternative to the mercury
portion of EPA Method 29 primarily because it is not validated for use
with impingers, as in EPA method, although the standard describes
procedures for the use of impingers. This European standard is
validated for the use of fritted bubblers only and requires the use of
a side (split) stream arrangement for isokinetic sampling because of
the low sampling rate of the bubblers (up to 3 liters per minute,
maximum). Also, only two bubblers (or impingers) are required by EN
13211, whereas EPA method requires the use of six impingers. In
addition, EN 13211 does not include many of the quality control
procedures of EPA methods, especially for the use and calibration of
temperature sensors and controllers, sampling train assembly and
disassembly, and filter weighing.
    The voluntary consensus standard CAN/CSA Z223.26-M1987,
``Measurement of Total Mercury in Air Cold Vapour Atomic Absorption
Spectrophotometeric Method,'' is not acceptable as an alternative to
EPA Method 29 (for mercury). This standard is not acceptable because of
the lack of detail in quality control. Specifically, CAN/CSA Z223.26
does not include specifications for the number of calibration samples
to be analyzed, procedures to prevent carryover from one sample to the
next, and procedures for subtraction of the instrument response to
calibration blank as in EPA method. Also, CAN/CSA Z223.26 does not
require that the calibration curve be forced through or close to zero
(or a point no further than 2 percent of the recorder full
scale) as in EPA method. Also, CAN/CSA Z223.26 does not include a
procedure to assure that two consecutive peak heights agree within 3
percent of their average value and that the peak maximum is greater
than 10 percent of the recorder full scale, as in EPA methods. CAN/CSA
Z223.26 does not include instructions for a blank and a standard to be
run at least every five samples, and specifications for the peak height
of the blank and the standard as in EPA method.
    Section 63.1349 to subpart LLL of this rule lists the testing
methods included in the regulation. Under Sec.  63.7(f) and Sec.
63.8(f) of Subpart A of the General Provisions, a source may apply to
EPA for permission to use alternative test methods or alternative
monitoring requirements in place of any required testing methods,
performance specifications, or procedures.

J. Congressional Review Act

    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing this rule and other
required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. A major rule cannot
take effect until 60 days after it is published in the Federal
Register. This action is not a ``major rule'' as defined by 5 U.S.C.
804(2). This rule will be effective on December 20, 2006.

List of Subjects in 40 CFR Part 63

    Environmental protection, Administrative practice and procedure,
Air pollution control, Hazardous substances, and Reporting and
recordkeeping requirements.

    Dated: December 8, 2006.
Stephen L. Johnson,
Administrator.

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For the reasons stated in the preamble, title 40, chapter I, part 63 of
the Code of Federal Regulations is amended as follows:

PART 63--[Amended]

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1. The authority citation for part 63 continues to read as follows:

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

Subpart LLL--[Amended]

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2. Sec.  63.1342 is revised to read as follows:

Sec.  63.1342  Standards: General.

    Table 1 to this subpart provides cross references to the 40 CFR
part 63, subpart A, general provisions, indicating the applicability of
the general provisions requirements to subpart LLL.

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3. Section 63.1343 is revised to read as follows:

Sec.  63.1343  Standards for kilns and in-line kiln/raw mills.

    (a) General. The provisions in this section apply to each kiln,
each in-line kiln/raw mill, and any alkali bypass associated with that
kiln or in-line kiln/raw mill. All gaseous, mercury and D/F emission
limits are on a dry basis, corrected to 7 percent oxygen. All total
hydrocarbon (THC) emission limits are measured as propane. The block
averaging periods to demonstrate compliance are hourly for 20 ppmv
total hydrocarbon (THC) limits and monthly for the 50 ppmv THC limit.
    (b) Existing kilns located at major sources. No owner or operator
of an existing kiln or an existing kiln/raw mill

located at a facility that is a major source subject to the provisions
of this subpart shall cause to be discharged into the atmosphere from
these affected sources, any gases which:
    (1) Contain particulate matter (PM) in excess of 0.15 kg per Mg
(0.30 lb per ton) of feed (dry basis) to the kiln. When there is an
alkali bypass associated with a kiln or in-line kiln/raw mill, the
combined particulate matter emissions from the kiln or in-line kiln/raw
mill and the alkali bypass are subject to this emission limit.
    (2) Exhibit opacity greater than 20 percent.
    (3) Contain D/F in excess of:
    (i) 0.20 ng per dscm (8.7 x 10-11 gr per dscf) (TEQ); or
    (ii) 0.40 ng per dscm (1.7 x 10-10 gr per dscf) (TEQ)
when the average of the performance test run average temperatures at
the inlet to the particulate matter control device is 204 [deg]C (400
[deg]F) or less.
    (c) Reconstructed or new kilns located at major sources. No owner
or operator of a reconstructed or new kiln or reconstructed or new
inline kiln/raw mill located at a facility which is a major source
subject to the provisions of this subpart shall cause to be discharged
into the atmosphere from these affected sources any gases which:
    (1) Contain particulate matter in excess of 0.15 kg per Mg (0.30 lb
per ton) of feed (dry basis) to the kiln. When there is an alkali
bypass associated with a kiln or in-line kiln/raw mill, the combined
particulate matter emissions from the kiln or in-line kiln/raw mill and
the bypass stack are subject to this emission limit.
    (2) Exhibit opacity greater than 20 percent.
    (3) Contain D/F in excess of:
    (i) 0.20 ng per dscm (8.7 x 10-11 gr per dscf) (TEQ); or
    (ii) 0.40 ng per dscm (1.7 x 10-10 gr per dscf) (TEQ)
when the average of the performance test run average temperatures at
the inlet to the particulate matter control device is 204 [deg]C (400
[deg]F) or less.
    (4) Contain total hydrocarbons (THC), from the main exhaust of the
kiln, or main exhaust of the in-line kiln/raw mill, in excess of 20
ppmv if the source is a new or reconstructed source that commenced
construction after December 2, 2005. As an alternative to meeting the
20 ppmv standard you may demonstrate a 98 percent reduction of THC
emissions from the exit of the kiln to discharge to the atmosphere. If
the source is a greenfield kiln that commenced construction on or prior
to December 2, 2005, then the THC limit is 50 ppmv.
    (5) Contain mercury from the main exhaust of the kiln, or main
exhaust of the in-line kiln/raw mill, or the alkali bypass in excess of
41[mu]g/dscm if the source is a new or reconstructed source that
commenced construction after December 2, 2005. As an alternative to
meeting the 41 [mu]g/dscm standard you may route the emissions through
a packed bed or spray tower wet scrubber with a liquid-to-gas (l/g)
ratio of 30 gallons per 1000 actual cubic feet per minute (acfm) or
more and meet a site-specific emissions limit based on the measured
performance of the wet scrubber.
    (d) Existing kilns located at area sources. No owner or operator of
an existing kiln or an existing in-line kiln/raw mill located at a
facility that is an area source subject to the provisions of this
subpart shall cause to be discharged into the atmosphere from these
affected sources any gases which:
    (1) Contain D/F in excess of 0.20 ng per dscm (8.7 x
10-11 gr per dscf) (TEQ); or
    (2) Contain D/F in excess of 0.40 ng per dscm (1.7 x
10-10 gr per dscf) (TEQ) when the average of the performance
test run average temperatures at the inlet to the particulate matter
control device is 204 [deg]C (400 [deg]F) or less.
    (e) New or reconstructed kilns located at area sources. No owner or
operator of a new or reconstructed kiln or new or reconstructed in-line
kiln/raw mill located at a facility that is an area source subject to
the provisions of this subpart shall cause to be discharged into the
atmosphere from these affected sources any gases which:
    (1) Contain D/F in excess of:
    (i) 0.20 ng per dscm (8.7 x 10-11 gr per dscf) (TEQ; or
    (ii) 0.40 ng per dscm (1.7 x 10-10 gr per dscf) (TEQ)
when the average of the performance test run average temperatures at
the inlet to the particulate matter control device is 204 [deg]C (400
[deg]F) or less.
    (2) Contain total hydrocarbons (THC), from the main exhaust of the
kiln, or main exhaust of the in-line kiln/raw mill, in excess of 20
ppmv if the source is a new or reconstructed source that commenced
construction after December 2, 2005. As an alternative to meeting the
20 ppmv standard you may demonstrate a 98 percent reduction of THC
emissions from the exit of the kiln to discharge to the atmosphere. If
the source is a greenfield kiln that commenced construction on or prior
to December 2, 2005, then the THC limit is 50 ppmv.
    (3) Contain mercury from the main exhaust of the kiln, or main
exhaust of the in-line kiln/raw mill, or the alkali bypass in excess of
41 [mu]g/dscm if the source is a new or reconstructed source that
commenced construction after December 2, 2005. As an alternative to
meeting the 41 [mu]g/dscm standard you may route the emissions through
a packed bed or spray tower wet scrubber with a liquid-to-gas (l/g)
ratio of 30 gallons per 1000 actual cubic feet per minute (acfm) or
more and meet a site-specific emissions limit based on the measured
performance of the wet scrubber.

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4. Section 63.1344 is amended as follows:
0
a. Revising paragraphs (c) through (e);
0
b. Adding paragraphs (f) through (i).

Sec.  63.1344  Operating limits for kilns and in-line kiln/raw mills.

* * * * *
    (c) The owner or operator of an affected source subject to a
mercury, THC or D/F emission limitation under Sec.  63.1343 that
employs carbon injection as an emission control technique must operate
the carbon injection system in accordance with paragraphs (c)(1) and
(c)(2) of this section.
    (1) The three-hour rolling average activated carbon injection rate
shall be equal to or greater than the activated carbon injection rate
determined in accordance with Sec.  63.1349(b)(3)(vi).
    (2) The owner or operator shall either:
    (i) Maintain the minimum activated carbon injection carrier gas
flow rate, as a three-hour rolling average, based on the manufacturer's
specifications. These specifications must be documented in the test
plan developed in accordance with Sec.  63.7(c), or
    (ii) Maintain the minimum activated carbon injection carrier gas
pressure drop, as a three-hour rolling average, based on the
manufacturer's specifications. These specifications must be documented
in the test plan developed in accordance with Sec.  63.7(c).
    (d) Except as provided in paragraph (e) of this section, the owner
or operator of an affected source subject to a mercury, THC or D/F
emission limitation under Sec.  63.1343 that employs carbon injection
as an emission control technique must specify and use the brand and
type of activated carbon used during the performance test until a
subsequent performance test is conducted, unless the site-specific
performance test plan contains documentation of key parameters that
affect adsorption and the owner or operator establishes limits based on
those parameters, and the limits on these parameters are maintained.
    (e) The owner or operator of an affected source subject to a D/F,
THC, or mercury emission limitation under

Sec.  63.1343 that employs carbon injection as an emission control
technique may substitute, at any time, a different brand or type of
activated carbon provided that the replacement has equivalent or
improved properties compared to the activated carbon specified in the
site-specific performance test plan and used in the performance test.
The owner or operator must maintain documentation that the substitute
activated carbon will provide the same or better level of control as
the original activated carbon.
    (f) Existing kilns and in-line kilns/raw mills must implement good