compliance tests should be based on the same methods. Cf. Chemical Waste
Management v. EPAu, 976 F. 2d 2, 34 (D.C. Cir. 1992) (“it is facially
reasonable to test compliance with a given standard under the same
sampling method used to develop that standard”). More basically, we
know of no case where a mercury CEMS has been successfully applied to a
cement kiln. We are also aware that two cement kilns in Florida that are
under constriction plan to install CEMS in the future. We plan to obtain
information from these sites once they are operational.

We agree with the final part of this comment. There are technical issues
to be resolved before mercury CEMS can be applied in this industry (such
as accounting for typically higher dust loading in the flue gas).

Comment: Two comments (0153, 0936) support the permitting, testing,
monitoring, and recordkeeping to be essential requirements in order to
conduct residual risk assessments and future regulations. The commenter
is concerned that new Portland cement facilities will be built without
regard to sources of mercury emissions at the facility or impacts. The
commenter states that without mercury standards, the industry will not
look for new and innovative ways to control mercury.

Response: We believe our new source standard for mercury kilns addresses
this comment. We have incorporated testing, reporting and recordkeeping
requirements in the final standards.

2.5	Impacts

Comments: Several commenters (0037, 0039, 0040, 0049, 0052, 0067, 0068,
0071, 0153, 0596) state that EPA has ignored or under valued 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 undercuts efforts to encourage
fish consumption as a way to reduce risk of heart disease. One commenter
(0596) 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: See the Federal Register notice for the final amendments for
the response to this comment.

Comment: Several commenters (0037, 0043, 0067, 0069, 0071) raised
concerns related to the local impacts of industrial mercury emissions.
According to one commenter (0037), 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 (0069) 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 (0067) states that EPA did not consider impacts of Hg hot
spots citing Florida and EPA research showing a reduction in local and
regional fish Hg 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 (0043) 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: See the Federal Register notice for the final amendments for
the response to this comment.

Comment: According to two commenters (0049, 0074), tribal groups are
disproportionately impacted due to loss of use of water bodies for
recreational, commercial and subsistence purposes. The commenters state
that EPA failed to consult with tribal groups. According to one
commenter (0074), as a treaty signatory, the U.S. government must abide
by treaty obligations to protect tribes' ceded territory rights
including protecting natural resources. The commenter states that the
portland cement plant located in Alpena, MI is in territory ceded in
1836.

Response: Tribal groups were given the opportunity to comment on the
proposed amendments, as were other interested groups. Specific
consultation with tribal groups is not required because tribal groups
are not specifically impacted: tribal groups do not own or operate
regulated sources. In addition, the NESHAP is developed as a section
112(d) standard. The main impact of concern noted in the comment was the
impact of mercury on water bodies. This impact is not considered in a
section 112(d) technology based standard. It will be considered during
the residual risk analysis under section 112(f) of the CAA.

Comment: Two commenters (0067, 0068) state that mercury’s impacts on
local waters result in disproportionate impacts on local populations and
have environmental justice implications. According to one commenter
(0068), the proposed rule is discriminatory in that it impacts on women
of childbearing age more than on other population segments.

Response: The commenter provided no data to allow us to assess this
comment. In any case, as noted above, the concerns of the commenter are
appropriately addressed during development of the residual risk standard
for this source category under section 112(f) of the CAA, and are not
relevant to the technology-based determination required by section 112
(d).

2.6	Fly Ash Ban

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. Several commenters (0077, 0060, 0046, 0044, 0046, 0047, 0055,
0057, 0059, 0070, 0072, 0075, 0355, 0078, 0102, 0682, 0805, 0938, 1325)
state that a ban is premature for several reasons with their objections
falling into one of several groupings: at odds with the RCRA objective
of encouraging environmentally beneficial waste recycling, predictions
based on the CAMR are speculative since that rule is being fiercely
contested 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 (0044, 0152) 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 (0047) 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 (0059) 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.

Commenter 0055 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 (0060) 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.

One commenter (0075, 0355) states that a fly ash ban contradicts a 1993
EPA statement that fly ash was non-hazardous (65 FR 32214, 32229). The
commenter also notes a 2004 study by U. of Nevada and EPRI that
concluded use of fly ash in concrete was of no environmental or health
concern.

Two commenters (0805, 0938) state that data from TRI showing that 64% of
kilns not using fly ash account for 60% of mercury emissions, while the
36% that do use fly ash account for about 40% 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 (0805, 0938), 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 (0805, 0938) 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 (0590) 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 (0591) 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 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: See the Federal Register notice for the final amendments for
the response to this comment.

Comment: Several commenters (0043, 0054, 0061, 0067, 0068, 0073) are
opposed to allowing the use of fly ash if it means increased mercury
emissions. One commenter (0068) cited a study showing that fly ash
mercury content can vary from 0.005 to 120 ug/g 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 (0054) 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 (0354) 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 Clean Air
Mercury Rule. 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 (0056, 0073, 0153) 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 (0073) 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 (0056) 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 (0153) 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 (0155, 0377) 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: See the Federal Register notice for the final amendments for
the response to this comment.

2.7	General

Comment: Several comments (0042, 0048, 0050, 0053, 0063, 0064, 0065,
0067, 0080-00101, 103-150) were submitted that disagreed with the
proposed amendments and requested that EPA impose stringent regulations
to reduce emissions of mercury from Portland cement plants.

One commenter (0053) states that EPA intentionally avoided public
involvement by holding a public hearing in North Carolina, a state with
no cement plants.

Response: The final amendments contain mercury standards based on the
MACT floor that are as stringent as allowed by law. Beyond-the-floor
standards were also considered, however, except for banning the use of
utility boiler fly ash with increased mercury content due to the use of
sorbent for mercury control, we did not believe the imposition of
beyond-the-floor standards was warranted considering the costs and
non-air environmental impacts.

	Concerning the public hearing location, we attempt to make the public
hearing accessible to the public at large. However, we typically select
a location where there is an EPA office to avoid costs associated with
renting a location. In this case, we saw no advantage to selecting a
location in a State that happened to have a cement kiln because cement
kilns are located in almost all states. Rather than pick one of the many
States that have cement kilns, we choose a convenient site where we had
EPA offices located.

3.0	HCl

3.1	Legal Issues Related EPA’s Interpretation of the CAA

Comment: Regarding EPA’s decision to not set HCl standards for
existing kilns, a commenter (0061) 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 (0596) 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: See the Federal Register notice for the final amendments for
the response to this comment. We also question the commenter’s
implicit assumption that “average” in section 112 (d) (3)
(“average emission limitation achieved by the best performing 12
percent of the existing sources”) must mean a numerical average (i.e.
arithmetic mean). The term can also mean a median (i.e. the median
emission limitation achieved), and EPA explains in the preamble to the
final rule (in the context of the floor determination for mercury for
existing sources) why it is reasonable to so interpret it here.

Comment: Two commenters (0061, 0155, 0377) took issue with EPA’s
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 (0061) 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: See the Federal Register notice for the final amendments for
the response to this comment.

3.2	Adequacy of Floor Determinations (Existing and New)

Comments: Regarding the proposed work practice standards for existing
kilns (operate at normal operating conditions and operate a particulate
control device), one commenter (0055) states that there is not enough
information to require “normal operating conditions” for kilns and
APCD. According to the commenter, “normal” kiln conditions may not
be best for HCl removal. This commenter also states that existing O&M
and SSM plans already ensure normal operation. Other commenters (0070,
0077) state that this proposed work practice is arbitrary as there is no
“normal operating conditions” 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. (See Appendix A of commenter 0077
submission.) One commenter (0045) 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 (0682) restating their
position on HCl that standards for existing and new kilns are not
necessary and do not represent the MACT floor.

Response: See the Federal Register notice for the final amendments for
the response to this comment.

Comment: One commenter (0054) favors specific HCl limitations or percent
reduction requirements over any risk-based approach. The commenter
believes that, given the alkaline nature of the cement manufacturing
process, it seems reasonable that EPA should be able to identify and to
monitor some process indicators for each kiln type relating to kiln
chemistry in order to quantify a percent reduction in HCl.

Response: This comment is moot because we have determined that
additional control of emissions of HCl is not necessary because current
emissions (and emissions from any new source) are at levels which would
be protective of human health with an ample margin of safety, and are at
levels which are protective of the environment. See section 112 (d) (4)
of the Act. However, we note that the commenter did not provide any data
or suggestions of the process indicators to monitor, or any information
of where data might be found. We know of no data, studies, or any other
information that would allow us to develop a percent reduction or
process monitoring scheme for Portland cement kilns that do not burn
hazardous waste (which are not part of the source category for this
rule). There is a percent reduction requirement for cement kilns that
burn hazardous waste. However, this limit was developed based on data on
the chlorine content of the hazardous waste and test data. This type of
information is not available for kilns that do not burn hazardous waste.

Comment: Three commenters (0055, 0070, 0077) state that PM and opacity
limits are sufficient to ensure capture of HCl in gas steam. Commenter
0055 adds that because the NESHAP general provisions and Subpart LLL
require cement plant operators to prepare and implement O&M and SSM
plans, compliance with these plans should ensure that HCl emissions are
inherently controlled and ensure that other HAP are minimized. The
commenter concludes that no additional work practice requirements are
necessary.

Response: This comment is moot because we have determined that
additional control of emissions of HCl is not necessary, based on the
authority of section 112 (d) (4) of the Act.

Comment: Three commenters (0055, 0070, 0077) state that little or no
test data is cited to support the proposed limits for new kilns (15 ppmv
or 90 percent removal). The commenter adds that EPA has not demonstrated
that the new source standard for HCl is achievable. Citing SO2 removal
efficiencies, one commenter (0155, 0377) states that EPA needs
additional emissions data from those portland cement plants that have
installed and operated wet or dry scrubbers in order to set standards
for HCl.

Response: This comment is moot because we have determined that
additional control of emissions of HCl is not necessary based on the
authority provided by section 112 (d) (4).

Comment: One commenter (0055) states that EPA has not demonstrated that
it has examined the cost 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 & annualized costs for a 1MM 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: See the Federal Register notice for the final amendments for
the response to this comment.

3.3	Beyond the Floor Determinations

3.3.1	Adequacy

Comment: Regarding beyond-the-floor standards for HCl,  one commenter
(0061) states that the CAA does not direct EPA to set standards it views
as reasonable for emissions reduction achieved; rather, the CAA directs
EPA to set standards that reflect the “maximum” degree of reduction
that is “achievable” considering the “cost of achieving such
emission reduction” and the other enumerated statutory factors.
According to the commenter, EPA misinterpreted the CAA, failed to
determine the maximum achievable degree of reduction, and exceeded its
authority by elevating its views about what level of reduction is
reasonable for the emissions reductions achieved over the CAA’s
requirement for the maximum achievable degree of reduction.

One commenter (0596) states that because at least two cement kilns
already are using limestone scrubber and RTO control devices that reduce
both organic and inorganic HAP, including HCl, EPA’s failure to
consider setting beyond-the-floor standards for HCl based on the use of
these controls is unlawful and arbitrary and capricious. The commenter
provided attachments to their comments containing information on these
two systems.

Response:  This comment is 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.  However, as discussed previously in the response to
a similar comment on potential mercury beyond-the-floor standards, we
believe that “achievable” emission reductions under section 112 (d)
(2) means reductions that are achievable after consideration of costs,
energy, and non-air health and environmental impacts, consideration of
which must be balanced against potential emission reductions.  See
Mossville, 370 F. 3d at 1236 (“[t]he EPA must balance these [emission
reduction] considerations with other factors such as cost, non-air
quality health and environmental concerns, and energy implications”).

The commenter also claimed that we had not considered the limestone
scrubbers and RTO control in series.  This statement is incorrect, and
reflects the mistaken belief that an RTO is an aspect of HCl control
(when in fact an RTO controls organic emissions, and the scrubber which
precedes it is necessary to enable performance of the RTO by preventing
plugging, fouling and corrosion).  We did consider limestone scrubbers
as a beyond-the-floor option for HCl control.  The fact that at two
facilities the limestone scrubber is followed by an RTO has no
implications for the overall level of HCl control because the RTO will
not remove additional HCl.  All potential HCl control occurs in the
limestone scrubber.  As discussed below and in section IV.C above, we
did evaluate the performance of a limestone scrubber/RTO control system
as both new source MACT and as an existing source MACT beyond-the-floor
option for THC (non-dioxin organic HAP) emissions.

3.3.2	Accuracy of costs

Comment: One commenter (0061) states that EPA fails to describe the
source of the scrubber costs, how they were calculated, and if they were
costs from the 1998 proposal that were updated, how they were updated
and whether the costs are considered accurate by EPA. According to the
commenter, the use of these unexplained costs as justification that
scrubbers are not reasonable for the emission reduction achieved is
arbitrary and capricious.

The commenter cites as flawed EPA’s reasoning that the generation of
scrubber slurry, and increased water and electricity usage would be
excessive and are additional reasons for rejecting scrubbers for
beyond-the-floor control for existing sources. The commenter states that
scrubbers always have these impacts but have been required by EPA in
other rulemakings; and further, that EPA does not say what levels are
considered excessive and why the levels for this industry are excessive.
The commenter states that this flawed analysis as part of EPA rejection
of scrubbers contributes to the commenter’s view that EPA’s
rejection of scrubbers is arbitrary and capricious.

Response: The comment is moot in regards to HCl for the reasons provided
in previous responses. However, we are responding to this comment
because we evaluated wet scrubber performance (and for beyond the floor
standards, costs) in evaluating standards for mercury.

We updated our scrubber costs based on the same scrubber designs
evaluated in the Industrial Boiler NESHAP. We believe these cost
estimates are now more accurate. For the mercury standard based on the
performance of a wet scrubber, costs are irrelevant because this is a
floor standard. In the case of the beyond-the-floor standards, we
evaluate all impacts and make a decision specific to this source
category (and no other) if the costs, energy and non-air impacts are
justified in relation to the emission reductions. In this case we
determined the beyond-the-floor impacts for an existing source mercury
standard based on wet scrubbers was not justified. Part of that decision
was the significant variability from site-to-site of the expected
mercury reductions, and the question about the scrubber performance in
removing mercury (i.e. how much of the mercury is in the oxidized form),
facts that are specific to this source category.

3.3.3	Accuracy of benefits

Comment: One commenter (0061) states that for existing kilns, EPA
understates HCl emissions reductions and overstates scrubber costs,
resulting in an overestimate of the cost per ton of HCl removed.
According to the commenter, the actual cost per ton of HCl removed is
reasonable and would be considered as an acceptable costs based on other
rulemakings. The commenter states that because EPA’s conclusion that
the cost of scrubbers is not reasonable for the emissions reductions
achieved rests on assumptions that are unexplained and irrational, and
varies without explanation from conclusions that EPA has reached
regarding acceptable cost per ton figures in other beyond-the-floor
analyses, it is arbitrary and capricious.

The commenter states that EPA ignores the co-benefits associated with
the use of wet scrubbers in the reduction in emissions of other HAP,
including mercury, formaldehyde and hydrogen fluoride. The commenter
states that EPA should consider the cost of scrubbers in light of all of
the HAP reduced.

Response: The comment is moot in regards to HCl because we have
determined that additional control of emissions of HCl is not necessary
based on the authority of section 112 (d) (4). However, we are
responding to this comment because we evaluated wet scrubber
performance, including potential to remove multiple HAP, in evaluating
standards for mercury.

Most of the points in this comment have been answered in the response
immediately above. In addition, we note that in the analysis in the
final rule amendments, we considered control of additional pollutants by
wet scrubbers, such as dioxins, and SO2 (a criteria pollutant, not a
HAP), and THC (which would include formaldehyde). We did not
specifically discuss hydrogen floruide (HF) because HF emission form
cement kilns are minimal. As explained in section IV.A.2 of the preamble
to the final rule, we did not consider existing source standards for
mercury based on performance of wet scrubbers to be achievable, within
the meaning of section  112 (d) (2), even taking into account the
additional non-mercury HAP removed. Dioxin removal is very modest
because it is incremental to the dioxin removal already required by the
rule. These modest co-benefits do not make the standard more reasonable,
considering control costs and adverse energy and nonair health and
environmental impacts associated with wet scrubber use for existing
sources.

3.4	Testing and Monitoring Related Issues

Comment: One commenter (0041) states that previously EPA estimated that
method 26 understates HCl emissions by up to 30 percent; therefore, EPA
should require HCl determinations by Method 320 or ASTM D6735-01. The
commenter states that EPA should make available any data used to support
its change of position regarding the use of Method 26.

Response: The comment is moot because we have determined that additional
control of emissions of HCl is not necessary based on the authority of
section 112 (d) (4). We are therefore not adding any additional test
methods for HCl in the final rule.

Comment: One commenter (0054) suggests that EPA require periodic HCl
emissions tests, at least once every 2.5 years.

Response: See previous response.

3.5	Risk-Based Sstandard

Comment: One commenter (0061) 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 reference concentration (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
section 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 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: See the Federal Register notice for the final amendments for
the response to this comment.

Comment: On EPA’s second risk-based approach (source-by-source risk
based approach), the commenter states that, as explained in their
comment above on EPA’s first risk-based approach, EPA lacks authority
to set any risk-based standards for HCl under CAA 112(d)(4). According
to the commenter, the source-by-source approach does not provided
emission standards; rather it provides sources a set of loose and
ill-defined criteria by which the source can set its own limits. The
commenter continues stating that CAA 112(d)(4) does not authorize EPA to
set source-specific risk-based limits, but, for pollutants for which a
health threshold has been established, EPA may consider such threshold
level, with an ample margin of safety, when establishing emission
standards under this subsection. Citing Congressional conference
proceedings, the commenter states that Congress considered and rejected
source-specific risk-based standards. The commenter states that an
additional flaw of the source-by-source approach is that the proposal
does not define clearly what would be involved. For example, the
commenter states that the “look-up” table and how it would work is
not well defined. Without these details, it is not possible to properly
evaluate and comment on the proposal and, therefore, would contravene
the CAA notice and comment provisions. The commenter states that EPA’s
approach to permitting and enforcement of its source-by-source
alternative limits is unlawful and arbitrary. According to the
commenter, EPA’s reference to the use of procedures similar to those
in the proposed hazardous waste combustor (HWC) rule does not explain
how the alternative limits would be approved, what opportunities there
would be for public review, comment and judicial review, nor does the
proposed HWC rule provide any coherent explanation of these issues.
Again, the commenter states that this precludes meaningful comment and
violates the CAA notice and comment provisions. The commenter states
that because EPA lacks authority to create an “applicable
requirement” through the title V permit program, its attempt to rely
on the title V program as the vehicle for establishing source-by-source
alternative limits is unlawful and arbitrary and capricious. The
commenter states that because any source-by-source limits that exist
only in a source’s title V permit necessarily would expire when the
permit expires, such limits are not emission standards.

Response: We have determined that a source-by-source risk based approach
is not necessary here, and did not pursue this alternative..

Comment: Several commenters (0054, 0056, 0073, 0153, 0155, 0377, 0937,
1324) oppose a risk-based approach for HCl. They oppose risk based
standards because they would be less stringent than the MACT floor. The
commenters state that it is inappropriate to exempt sources based on
risk under a MACT standard. According to the commenters, the CAA
requires two-step process: first, MACT is established, a
technology-based program that calls for all major sources to install
stringent controls, and; second and subsequently, remaining risks are
evaluated after implementation of MACT standards.

One commenter (0041) states that EPA should set technology-based
standards, as required by the CAA, rather than risk-based standards,
arguing that risk standards will be less stringent that MACT floor
standards. The commenter states as an additional reason for setting a
MACT standard that the air quality near the source may change after a
permit has been issued. And if EPA insists on setting risk-based rules,
the commenter states that they should include consideration of
ecological effects.

One commenter (0153) opposes the risk-based approach stating that
sources may meet a federal exclusion only to then face a differing state
standard. According to the commenter, absence of a national MACT
standard will lead to a patchwork of state standards and create
uncertainty and an uneven playing field for the industry.

One commenter (0155, 0377) states that EPA must collect the data needed
to make appropriate decisions, including the data needed to do a
national assessment of HCl emissions and risks. The commenter states
that these data would be available if EPA enacted the Consolidated
Emission Reporting Rule for HAP and not just criteria pollutants.

Response: The Act includes certain exceptions to the general statutory
requirement to establish emission standards based on the performance of
MACT. Thus, EPA disagrees with the comment that EPA must in all cases
use the two-step process set out in section 112 (d0 (3) (floor
determinations) and 112 (d) (2) (beyond the floor determinations). Of
relevance here, section 112(d)(4) provides EPA with authority,  to
develop risk-based standards for HAP's "for which a health threshold has
been established", provided that the standard achieves an "ample margin
of safety." (The full text of the section 112(d)(4): "[w]ith respect to
pollutants for which a health threshold has been established, the
Administrator may consider such threshold level, with an ample margin of
safety, when establishing emission standards under this subsection.")
Legislative History confirms that this provision was intended to
authorize EPA to consider risk and not to establish standards reflecting
MACT, under the circumstances enumerated in section 112 (d) (4). (Staff
of the Senate Committee on Environment and Public Works, A Legislative
History of the Clean Air Act Amendments of 1990, Vol. 1 at 876,
statement of Senator Durenberger during Senate Debate of October 27,
1990: "With respect to the pollutants for which a safe threshold can be
set, the authority to set a standard less stringent than maximum
achievable control technology is contained in subsection (d)(4).") The
legislative history further indicates that if EPA invokes this
provision, it must assure that any emission standard results in ambient
concentrations less than the health threshold, with an ample margin of
safety, and that the standards must also be sufficient to protect
against adverse environmental effects (S. Rep. No. 228, 101st Cong. at
171). Costs are not to be considered in establishing a standard pursuant
to section 112(d)(4) (Ibid.). Therefore, EPA believes it has the
discretion under section 112(d)(4) to develop risk-based standards for
some categories emitting threshold pollutants, which may be less
stringent than the corresponding "floor"-based MACT standard would be.
In applying this authority, EPA seeks to assure that emissions from
every source in the category or subcategory are less than the threshold
level to an individual exposed at the upper end of the exposure
distribution, a most exposed individual assuming exposure pathways which
could occur. The EPA believes that assuring protection to persons at
this upper end of the exposure distribution is consistent with the
"ample margin of safety" requirement in section 112(d)(4). Moreover. if
emissions of the threshold pollutant are at protective levels, with an
ample margin of safety, and emissions are less than levels which result
in adverse environmental effects, then there is no necessity of a
standard. As explained in section IV.A.2 of the preamble to the final
rule, those are the facts here.

	Since proposal we have obtained data on a risk analysis for HCl
emissions for cement kilns. We evaluates these data and determined that
no additional control of HCl emissions is warranted. We believe the data
provided by the Portland Cement Association s sufficient to make this
determination.

Give the fact that HCl is not a criteria pollutant, and HCl emissions
from cement kilns are typically low (due to the alkaline environment of
a cement kiln), we see little possibility that they will become subject
to differing State standards. We know of no States that currently
regulate HCl emissions from cement kilns.

Comment: Two commenters (0070, 0077) submitted comments on the need for
HCl standards. According to the commenters, based on a risk analysis
using 14 PH/PC kilns at 13 cement plants using a range of in-stack HCl
concentrations as well as a sensitivity analysis using higher HW 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 (0077), one commenter
(0590)  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 (0590) conducted a study to evaluate the long term and
short term health risks of HCl emissions from 94 kilns at 71 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 reference concentration (RfC) threshold for chronic health
effects or Cal EPA’s reference exposure level (REL) 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 (0682) 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: See the Federal Register notice for the final amendments for
the response to this comment.

Comment: Three commenters (0055, 0070, and 0077) state that if EPA
persists and requires HCl standards, they should provide for
site-specific alternative risk-based standards under 112(d)(4) as done
for the industrial boiler MACT rule and the HWC MACT  rule. (0077)

Response: We considered a site specific risk approach. However, since
proposal we have determined that further control of HCl emissions is not
warranted. Therefore, there is no further need to consider a site
specific risk based approach for HCl.

Comment: One commenter (0071) states that the proposed rule inadequately
addresses the health risk from HCl and especially the health of children
who, because they breathe more rapidly, inhale more pollutants per pound
of body weight and have smaller diameter airways relative to adults;
thus they may be more vulnerable to the effects of HCl exposure.

Response: The commenter provided no data to allow us to address this
claim. Data from other sources indicates that further control of HCl
emissions is not necessary because HCl emissions from cement kilns would
remain at levels protective of health with an ample margin of safety and
would be at levels protective of the environment. See section IV.B of
the preamble for the final rule amendments.

4.0	THC

4.1	Legal Issues Related EPA’s Interpretation of the CAA

Comment: Regarding emission standards for total hydrocarbons (THC), one
commenter (0061) 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
(0596), 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: See the Federal Register notice for the final amendments for
the response to this comment.

4.2	Adequacy of Floor Determination (Existing and New)

Comments: One commenter (0596) states that EPA has improperly borrowed
standards from its 1999 regulations for hazardous waste combustors,
which were found unlawful and vacated, rather than setting standards
that reflect the THC or CO emission levels actually achievable by the
best performing sources (12% 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 affect 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 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.

Response: See the Federal Register notice for the final amendments for
the response to this comment.

Comments: Several commenters (0045, 0055, 0070, and 0077) state that it
is inappropriate to set MACT floor limits based on a different source
category, i.e., hazardous waste combustors (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 of going nonhazardous when exceeding limit using
automatic waste feed cutoff (AWFCO) and that the HWC THC standard only
applies when hazardous waste is being burned.

Commenters 0055, 0070, and 0077 state that the HWC MACT standards were
based on EPA’s RCRA Boiler and Industrial Furnace (BIF) 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: In setting MACT floors for existing sources we determine the
median of the top 12 percent of the best performing kilns. As previously
noted, we were unable to establish best performance in the original
NESHAP due to the influence of feed materials organic contents on
measured THC emissions, which essentially created uncontrollable
variability. However, at proposal we determined that variability of
organic emissions attributable to fuel inputs is controllable because
such control is not dependent on organic levels in raw materials, and
the fuel combustion process can be controlled to minimize THC emissions.
The existence of THC emission limits for cement kilns that burn
hazardous waste established a level of best performance, even
considering the fact that most of the THC emissions measured at the kiln
stack were the result of organic materials in the kiln feed. Also, we
believed at the time of proposal that kilns that burn hazardous waste do
not have differences from kilns that do not burn hazardous waste.

	However, after a review of comments we have determined that there are
two significant differences we should have considered. One is that
currently a kiln that burns hazardous waste can intermittently turn off
the hazardous waste feed, and not be subject to the THC limits, if they
see a potential exceedence due to uncontrollable short term increases in
THC resulting from raw materials inputs. The second is that a facility
can permanently stop burning hazardous waste if their raw materials
would result on their inability to meet the THC limits. However, in both
cases terminating the burning of the hazardous waste does not impede
their ability to continue to produce product. In addition, we have
obtained additional data on THC emissions that indicate that, even
operating with good fuel combustion conditions,  the variability of the
raw materials’ organic contents for the industry as a whole would
result in a significant percentage of cement kilns being unable to meet
the proposed floor standard. This result is inconsistent with the
premise of the proposal, which was to codify best performers’ good
fuel combustion practices.

	We had also provided in the proposed standards option to measure THC
emissions in the alkali bypass, or through a mid kiln sampling system.
These sampling points have the benefit that the measurements are
upstream of the point where the feed materials enter the kiln.
Therefore, varying levels of organics in the feed do not affect THC or
CO emission levels measured in the alkali bypass or mid kiln. However,
only about one in three cement kilns have an alkali bypass, and the one
kiln with a mid-kiln gas sampling system has changes to an alternative
monitoring process because the location of a mid-kiln sampling system
creates severe maintenance issues. Therefore, we do not consider
mid-kiln gas sampling to be feasible.

	As a result, in the final amendments was have removed the monitoring
requirements  and emission limits for existing source and substituted a
work practice standard of good combustion conditions. For new sources
the basis of the standard is an add-on control.

Comment: One commenter (0055) states that EPA’s incorporation of the
MACT floor for HWC-MACT kilns to NHW kilns is inappropriate because EPA
has switched focus from establishing a MACT floor for THC to combustion
THC, which may only be a small contributor overall THC emissions. The
commenter suggests that EPA evaluate the MACT floor based on total THC
emissions.

Response: We evaluated MACT floors for total THC emissions. For existing
sources, the only potential floor was good combustion conditions, since
other emissions are entirely dependent on raw material organic content,
which varies enormously from kiln-to-kiln and at individual kilns as
well. We are aware that this practice only controls combustion THC not
THC from organic materials in the feed. However, we could identify no
control that could form the basis of a floor for THC form organic
materials in the feed. For new sources, the THC standard is now measured
at the stack and limits both combustion THC and THC from organics in the
feed.

Comments: Three commenters (0055, 0070, and 0077) state that EPA has no
empirical data demonstrating that any non-hazardous waste (NHW) kiln can
achieve the proposed limits on a continuous basis. Commenter 0077 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: See the Federal Register notice for the final amendments for
the response to this comment.

Comment: Three commenters (0070, 0077, 0682) 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 (0077) notes that available
information (Rigo & Rigo Assoc & Schreiber, et al) 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 (0682) states that the high temperatures required for the
formation of cement clinker (>2700F) ensure as complete combustion of
fuels as is possible.

Response: See the Federal Register notice for the final amendments for
the response to this comment.

Comment: Three commenters (0045, 0070, and 0077) state that it is
inappropriate to apply limits 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 (0070 and 0077) add that a Reaction Engineering
study shows that organics emitted from kiln feed is extremely variable
across US and ranges over 4 orders of magnitude.

Response: See the Federal Register notice for the final amendments for
the response to this comment.

Comment: Commenter 0045 states that as done for HCl, EPA should require
“operation of kiln following good combustion practices”, and there
is no need for a numerical limit for THC from existing sources.

One commenter (0590) remains opposed to the THC standard for existing
kilns repeating its comments on the original proposal (0077) that THC
emissions from cement kilns are derived almost exclusively from organic
compounds contained in the raw materials and that raw materials are
chosen when plants locations are chosen. The commenter states that since
proposal, EPA has acknowledged that their intent was to ensure the
complete combustion of organic compounds derived from fuels and not to
prohibit cement plants from using nearby raw materials. The commenter
states that kiln design, including process temperatures well above those
needed to destroy organic compounds, ensure complete destruction of
fuel-derived organic compounds and the conversion of raw materials into
clinker. According to the commenter, plant operators closely monitor
combustion to ensure a proper kiln environment to convert raw materials
to the clinker product. The commenter states that it will supply EPA
with a proposed work practice approach currently used in the industry
that could be used by plant operators to demonstrate good combustion.
The commenter notes that testing of organic materials from cement kilns
that burn hazardous waste indicates that regardless of the fuel type,
neither acute nor chronic risk thresholds for organic hazardous air
pollutants are exceeded.

Response: We agree with this comment. We have removed the numerical THC
limits for existing source limits and based the standard on good
combustion practices. For new sources the basis of the standard is now
an add-on control, so this comment no longer applies.

Comment: One commenter (0045) states that it is illogical to set more
stringent limits for existing kilns (20 ppmv) than for new greenfield
kilns (50 ppmv)

Response: In the final amendments there are now no quantified limits for
existing sources. The new source limit is now 20 ppmv for all new kilns.

Comment: Two commenters (0070 and 0077) state that EPA has acted
arbitrarily by proposing THC standards for sources other than greenfield
kilns without explaining why its previous rationale for limiting the
standard to greenfield kilns, that raw material selection is not
available for existing kilns because facilities are generally tied to
existing raw materials sources in close proximity to the facility, is no
longer valid.

Response: We have removed the numerical THC limits for existing source
limits and based the standard on good combustion practices. Therefore,
existing kilns do not have to meet any specific limits. The reason for
subcategorizing existing plants greenfield sources was that when
selecting a new greenfield source a source can choose to site the raw
material quarries where the organic contents are low enough to meet the
current 50 ppmv limit. Because the basis of the floor was raw material
selection, rather then an add-on control, this control technique is only
available to greenfield sites. For new sources the basis of the standard
is now an add-on control. In that case a facility can exercise control
of THC emission regardless of the organic content of the raw materials.
Therefore, there is no reason to subcategorize existing plants and
greenfield plants. Moreover, since the control achievable an RTO (20 ppm
or 98 % emission reduction) is superior to that based on raw material
selection (50 ppm), the standard applies to all new sources. Put another
way, the 50 ppm standard for Greenfield sources adopted in the 1999
final rule no longer reflects the performance of the best performing
source, and thus cannot reflect the MACT floor for new sources.

Comment: Two commenters (0070 and 0077) point out that EPA appears to
make changes to the current requirement for new greenfield kilns of 50
ppmv measured in the kiln stack by establishing an additional CO
standard for kilns equipped with alkali bypass systems. The commenter
requests that EPA confirm in the final rule that only the 50 ppmv stack
gas limitation applies to new, greenfield kilns.

Response: It was our intent in the proposed rules that new greenfield
kilns meet a 50 ppmv limit at the stack, and potentially also meet a 20
ppmv limit at the stack if the kiln had no alkali bypass. We agree that
this could appear illogical. However, in the final amendments all new
kilns must meet a 20 ppmv standard. Therefore, this comment is now moot.

Comment: One commenter (0155, 0377) supports the limits for CO and THC
to ensure adequate combustion and believes that 1 year for compliance is
sufficient.

Response: Other comments and data we received after proposal have
indicated that our premise at proposal was flawed. Therefore, we do not
agree with this comment. Additional information on the reasons can be
found in section IV.C of the preamble of the final rule amendments.

4.3	Beyond the floor determination

Comment: A commenter (0061) 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 (0596) 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 good combustion practices;
2) EPA did not show that its standards reflect the maximum degree of
reduction achievable through combustion controls in light of its
findings that nonhazardous waste 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 as well as mercury and dioxin; 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 do reflect 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.

Response: See the Federal Register notice for the final amendments for
the response to this comment.

4.4	Area sources

Comment: Several commenters oppose EPA’s proposed regulation of area
sources for THC. Three commenters (0055, 0070, and 0077) 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 (0045) 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: See the Federal Register notice for the final amendments for
the response to this comment.  See also 63 FR 31911.

4.5	Testing and Monitoring Related Issues

Comment: One commenter (0054) supports EPA requirements for THC or CO
monitoring as indicators of good combustions for the control of organic
HAP. The commenter also supports the requirement of a THC emission tests
if a facility elects to monitor CO, although the commenter recommends
more frequent THC compliance testing, at least once every 2.5 years.

Response: We would agree with this comment in regard to measuring THC or
CO in a kiln alkali bypass or mid-kiln gas sampling system. However, if
the THC and CO are measured after the introduction of the feed
materials, organic material in the feed can result in significant THC
emissions that have no relationship to whether or not the kiln is using
good fuel combustion practices. The comment on THC compliance testing is
now moot because we are requiring THC CEMs whenever a facility has a THC
emissions limit.

Comment: One commenter (0045) 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: See the Federal Register notice for the final amendments for
the response to this comment.

Comment: Because mid-kiln monitoring for good combustion may be an
alternative to monitoring main kiln exhaust gases where THC levels may
be higher due to organics from the limestone, several comments were
received on the difficulties associated with mid-kiln monitoring.
Several commenters (0055, 0070, 0077, 0682) state that the proposed
mid-kiln monitoring on long kilns is not reliable, has operational
problems and is maintenance intensive. One commenter (0077) adds that
mid-kiln sampling systems can be complex, extremely costly to maintain,
and can prevent optimal cement manufacturing goals from being achieved.

According to commenter 0055, operational problems include 1) obtaining a
proper seal on the mid-kiln system to avoid in-leakage of ambient air
from outside the kiln, 2) sample tube life, and 3) loss of production.
The commenter states that mid-kiln monitoring systems are expensive to
install and maintain and provide unreliable results. The commenter
reports spending over $2 million to install its system and over $100,000
annually on maintenance of the system. The commenter adds that the
system is estimated to be responsible for $2 to $3 million dollars of
lost production annually and higher than necessary emissions of NOX and
other criteria pollutants.

One commenter (0055) states that a number of cement kilns have installed
mid-kiln firing to comply with the NOX SIP call or for other reasons.
According to the commenter, use of mid-kiln monitoring systems has never
been attempted with mid-kiln firing systems. The commenter states that
there is no reason to believe such systems are a viable monitoring
technology for such kilns or that such monitoring systems would be the
proper means of verifying good combustion in that environment.

One commenter (0077) notes the use of an alternative to mid-kiln
sampling adopted at a facility due to the costly and maintenance
intensive nature of mid-kiln sampling. The commenter notes that, as a
surrogate for good combustion, a minimum temperature was set at two
points in the kiln at the facility (flame temp. and inlet to chain
section of long wet kiln) along with a minimum oxygen level. These were
set while demonstrating good combustion during a destruction and removal
efficiency (DRE) test as part of this method’s comprehensive
performance test (CPT) to prove the alternative was effective. The
commenter reports that as long as the kiln remains within the limits set
during the CPT, good combustion can be demonstrated. The commenter also
includes data in Appendix C of its comments that show although THC
monitoring costs for preheater/precalciner kilns are less than mid-kiln
monitoring systems, they are still significant. The commenter adds that
if EPA were to promulgate a THC standard for existing kilns, these costs
(over $180,000 in design and installation costs and $25,000 to $30,000
in annual operating costs) would be incurred by more than 30
preheater/precalciner kilns.

If EPA persist in requiring monitoring of combustion-based THC, one
commenter (0682) requests that EPA consider an alternative work practice
or operating procedure that would demonstrate good combustion practices,
which the commenter plans to work on.

Response: We agree with these comments. We have replaced the monitoring
requirements in the proposed rule with a work practice requirement in
the final amendments establishing standards for existing sources. For
new sources the THC emission limit is now based on the performance of a
regenerative thermal oxidizer and requires a THC CEM in the main stack.
Therefore, these comments no longer apply.

Comment: Two commenters (0070 and 0077) state that it is impractical, as
proposed, to import low organic feed materials to conduct a THC
performance test in order to be allowed to monitor CO.

Response: We agree and have changed the final rule amendments so this is
no longer required.

5.0	Raw material storage

Comment: Two commenters (0054, 0058) favor including all crushers in the
Portland cement NESHAP and include Subpart OOO, if they satisfy the
requirements of the CAA. One commenter (0058) cites State requirements
for primary crushers of 10 percent opacity, work practices, and a
baghouse with outlet concentration of 0.01 gr/dscf; 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 (0058) 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: See the Federal Register notice for the final amendments for
the response to this comment.

Comment: One commenter (0060) states that all of the raw material
handling and storage, except crushing, should be covered by the NESHAP.
They state that the only non-metallic mining activities subject to the
NSPS Subpart OOO are at the quarry and 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: See the Federal Register notice for the final amendments for
the response to this comment.

Comment: Two commenters (0070 and 0077) state that both suggested
approaches confound the agreement between PCA and EPA to clarify which
sources are subject to OOO and those subject to LLL with the intent of
including under LLL only those sources related to cement manufacturing.
The commenters state that further discussions between the Portland
Cement Association (PCA) and EPA are needed.

Response: The EPA and PCA have had several meetings on this issue.
Unless there is new data to consider, we believe additional meetings on
this issue are unnecessary. In taking our final action on this matter we
had discussions with the PCA and went through a comment and response
rulemaking. This action supersedes any previous rulemaking or prior
agreements with the PCA.

6.0	Other

Comment: One commenter (0077) states that EPA should explain in the
final rule that the owner of an in-line kiln/raw mill which co-mingles
virtually all of the clinker cooler gases with kiln exhaust gases will
be subject to a weighted opacity standard based on the percentage of
clinker cooler gases used by the kiln/raw mill during its normal mode of
operation. The commenter believes that a 20 percent opacity standard
would continue to apply to the preponderance of in-line kilns/raw mills
that route all of their clinker cooler gases through the kiln stack.

Response: The rule’s opacity standards were not opened for comment at
proposal. Therefore we are not  responding to this comment.

Comment: Two commenters (0070 and 0077) state that the one year
compliance period is not adequate, given formal processes imposed by
states to authorize installation and use of CEM, such as the THC and CO
CEM. According to the commenter, at least 2 yrs or 30 months should be
allowed.

Response: We agree with this comment in regard to existing sources.
However, because existing sources no longer have THC emission limits,
this comment is moot for existing sources. For new sources the
compliance date is set by the statute.

Comment: One commenter (0937) states that EPA should require PM CEMs to
ensure compliance and remove the current PM CEM deferral. The commenter
states that PM performance specifications (PS-11) have been promulgated
and it is now appropriate to require PM CEMs for portland cement plants.
The commenter also states that EPA should require monitoring of mercury,
HCl, and THC more frequently than every 5 years, with continuous
monitoring preferable or case-by-case exemptions.

Response: We did not propose changes to the portions of the rule on use
of PM CEMS or  testing frequency. Therefore, we are not responding to
this comment.

Comment: One commenter (0937) states that the startup, shutdown, and
malfunction exemptions does not provide adequate protection of human
health and is contrary to the CAA’s requirements to protect human
health and should be eliminated.

Response: We did not propose changes to the portions of the rule
concerning startup, shutdown, and malfunction exemptions. Therefore, we
are not responding to this comment.

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		Response to Comments Document

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		Response to Comments Document

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