CEMS. Similarly, we believe that PM CEMS are a superior technology as
well. However, we would be happy to review evidence supporting more
advanced COMS systems.

Comment: One commenter (2859) stated that EPA has not specifically
stated in the rulemaking what the averaging period for the PM MACT
standard will be. EPA has specified that the averaging periods for
mercury, THC, and HCl are 30-day rolling averages. EPA has proposed CEMS
for compliance demonstration for each of these pollutants. For
consistency purposes, EPA should designate that the PM MACT standard
should also be a 30-day rolling average if a PM CEMS is used to
demonstrate compliance. If sources choose to use BLDS or other approved
compliance demonstration methods, then a performance test consisting of
the average of three one-hour stack testing periods would be the
appropriate compliance averaging period for the PM MACT standard.

One commenter (2845) stated that there is no reference in §63.1343(a)
to the averaging period for the PM limit if PM CEMS are used. The
commenter suggested that the last sentence of §63.1343(a) be changed to
read, If using a CEM to determine compliance with the PM or HCl
standards, these standards are based on a 30–day rolling average.

Response: We have corrected the rule to provide for a 30-day rolling
average when using PM CEMS.

Comment: Two commenters (2845 and 2859) stated that EPA should clarify
whether an ESP predictive model may be used in lieu of other PM
monitoring approaches and what requirements would apply if this option
is selected. No mention of an ESP predictive model is found in the
performance testing or monitoring sections of the proposed rule. If EPA
allows use of a predictive ESP model as an alternative to other
monitoring, then the minimum parameters and technical criteria for
determining the acceptability of the predictive model should be
specified.

Response: We will consider source-specific requests to use an ESP
predictive model

Comment: Two commenters (2845 and 2859) stated that it should be
clarified that kiln/raw mill and cooler stack(s) that have installed
BLD, PMD, or PM CEMS would not be subject to monthly 20-minute visible
emissions test of each affected source in accordance with Method 22
under §63.1350(a)(4)(i).

Response: We have corrected the rule to remove this duplicative
requirement.

Comment: Two commenters (2845 and 2859) stated that EPA has not provided
any technical basis for changing the duration of the Method 22 test in
§63.1350(a)(4)(i) and that changing the duration from 1 minute to 20
minutes for numerous sources places an unnecessary burden on the plant
operators. An increase in the duration of visible emissions from 1
minute to six minutes would be a more reasonable change and would be
more consistent with the minimum observation period for Method 9 visible
emission observations.

Response: While we do not think this is an unreasonable requirement once
per month, we have reduced the observation period in half to 10 minutes,
which should be sufficient to observe any problems. There is no reason
to be consistent with a Method 9 observation period, because the tests
are different.

Comment: One commenter (2845) stated that Equations 3 and 4 apply a
metric conversion factor to the emission rate. The commenter stated that
the formula does not work in metric units, and suggested alternative
wording for these equations that had the emission rate in only lb/ton.

Response: We have not been able to identify the problem raised by the
commenter. The units in the equations are those that are commonly
measured.

Comment: One commenter (2845) stated that §63.1349(b)(1)(vi) should
either be removed or updated to account for clinker coolers. The
averaging period for sources using PM CEMS for compliance with the
particulate matter standards should be based on a 30-day rolling
average. The commenter noted that there is no need to conduct a separate
performance test under raw mill on/off conditions when using a PM CEMS
for measuring compliance as the PM CEMS will measure compliance and thus
account for both conditions.

One commenter (2845) stated that §63.1350(a)(4)(v) indicates that
visible emissions monitoring requirements do not apply to totally
enclosed conveying system transfer points. However, §63.1349 does not
currently indicate that initial performance testing is not required for
totally enclosed conveying system transfer points. Section 63.1349
should be revised to clarify that initial performance testing is not
required for totally enclosed sources.

Response: We have corrected the rule to remove the inconsistencies
identified by the commenter. We have also clarified the rule to specify
a 30-day rolling average.

Comment: One commenter (2845) stated that §63.1350(a)(4)(vii) indicates
that you must test visible emissions from each side, roof, and vent of
the building. However, this is not included in the initial performance
testing section. Section 63.1349 should be revised to be consistent with
the wording in §63.1350(a)(4)(vii). Further, a 6 minute observation
should be sufficient to demonstrate compliance with visible emissions
standards. The 6 minute duration would also be consistent with the
minimum observation time for a Method 9 data set (40 CFR 60 Appendix A,
Method 9, Section 2.5 Data Reduction). The commenter provides example
alternative language.

Response: We have corrected to the rule to include the performance
testing requirements. Regarding the length of the observation period, we
have reduced the period to 10 minutes, which should be sufficient to
observe any problems. There is no reason to be consistent with a Method
9 observation period, because the tests are different.

Comment: One commenter (2845) stated that in regard to §63.1349(b)(2),
the proposed rule should specify test requirements for sources with
limited operation. An option would be to use language similar to that
used in NSPS Subpart OOO (see 40 C.F.R. §60.675(c)(2)(ii): The duration
of the Method 9 (40 C.F.R. Part 60, Appendix A–4) observations may be
reduced to the duration the affected facility operates (but not less
than 30 minutes) for baghouses that control storage bins or enclosed
truck or railcar loading stations that operate for less than 1 hour at a
time.).

Response: The observation does not need to be consecutive, which we have
clarified in the final rule to address this situation.

Comment: One commenter (2845) stated that the proposed requirement to
conduct five 6-minute Method 9 tests is unnecessary. No rationale was
provided for the increase in the number of tests.

Response: This test is only required when visible emissions are
identified, which should be a limited occurrence. However, when it does
occur, we think that conducting a valid Method 9 test would take at
least 30 minutes.

Comment: One commenter (2845) stated that §63.1350(k) does not
currently address PMDS. Multiple portland cement plants currently use
PMDS for compliance with Subpart EEE, and language used in
§63.1206(c)(9) (NESHAP Subpart EEE) provides PMDS requirements for
Hazardous Waste Combustors that utilize PMDS to monitor compliance with
PM standards which could be used as a template for inclusion in Subpart
LLL.

Response: We will consider source-specific requests to use PMDS

Comment: One commenter (2845) stated that an exclusion installing,
operating, and maintaining a BLDS for sources using a PM CEMS should be
included in §63.1350(k). The commenter also noted that the rule only
applies to sources with fabric filters, which is not a defined term. For
clarification, the rule should specifically state that it does not apply
to sources with gravel bed filters and ESPs.

Response: We have clarified that sources using a PM CEMS are not
required to use a BLDS. We have clarified in the final rule that fabric
filters do not include gravel bed filters and ESPs.

Comment: One commenter (2845) suggested that EPA delete
§63.1350(k)(1)(i) or develop design and performance specifications for
manufacturers to certify their BLDS to meet the criteria required in
this section.

Response: The proposed requirements have been used successfully in
several other rules. EPA is developing a BLD performance specification
that will be put in place when it is available.

Comment: One commenter (2845) stated that in §63.1350(k)(2), the phrase
At a minimum you must retain records related to the site specific
monitoring plan and information discussed in paragraphs (k)(2)(i)
through (k)(2)(vi) of this section for a period of 2 years on-site and 3
years off-site implies that off-site record storage is mandatory rather
than optional. The commenter suggested that EPA should only specify the
minimum period of time required for overall record retention and the
minimum period of time required for onsite storage, leaving the option
for offsite storage to the discretion of the owner/operator.

Response: We agree with the clarification suggested by the commenter and
have added it to the rule.

Comment: One commenter (2845) stated that §63.1350(k)(4) references
kilns and clinker coolers, but only the emission limits in §63.1343,
which is for kilns. To be consistent with §63.1350(p), the clinker
cooler emission limit reference would need to be added. However, this
paragraph is also a duplicate of §63.1350(p) introducing the PM CEM
requirements and it would be more appropriate to delete it altogether to
prevent confusion.

Response: We agree and have made the change suggested by the commenter.

Comment: One commenter (2845) stated that the reference to new or
existing sources should be removed from §63.1350(o). This should apply
to all sources; new, existing, or reconstructed.

Response: We agree with the clarification suggested by the commenter and
have added it to the rule.

Comment: One commenter (2845) stated that opacity standards only apply
to sources that elect to utilize a COM for PM compliance demonstration,
therefore, correlations with opacity will no longer be needed and should
be deleted from portions of §63.1357.

Response: We agree with the clarification suggested by the commenter and
have added it to the rule.

Transmisometers

Comment: One commenter (2879) stated that the European cement industry
has used transmisometers to report PM emissions for many years. The
commenter stated that opacity readings underreport PM emissions, and
provided emission test data using transmisometers. The commenter also
noted that BLDS are not adequate to measure noncompliance, and
recommended that EPA should adopt regulations similar to those
established in Europe, the parent companies of most American cement
companies, that require particulate emissions and associated metals
emissions be determined using monthly averaged transmisometer readings.

Response: We have clearly established the value of PM CEMS for this
industry, and we believe PM CEMS are superior to BLDS for this industry.

Advantages of opacity standards

Comment: One commenter (2786) stated that EPA should not eliminate
opacity standards in the proposed rule. The commenter stated that there
are benefits to having an opacity standard in conjunction with a
particulate matter standard. Opacity measurements can be made by anyone
who is trained to measure opacity, which can include members of the
public and not just inspectors, and opacity measurements are a cheaper
method of getting more frequent measurements.

Response: See response in preamble

Monovent compliance demonstration

Comment: One commenter (2888) requested that monovent kilns be allowed
to continue compliance demonstration as outlined in the current PC MACT.
The monovent design orientation does not provide a means for either BLD,
a PM CEM or and opacity monitor.

Response: The rule contains the necessary and appropriate monitoring
requirements. Monovent sources can add a stack. Or, they can apply for
alternative monitoring requirements on a source-specific basis.

Require PM CEMS and retain opacity monitors

Comment: One commenter (2898) stated that EPA should require PM CEMS and
retain the opacity monitoring requirements. EPA is proposing
installation and operation of a BLD system, along with stack testing
using EPA Method 5 conducted at a frequency of five years for
demonstrating compliance with the proposed PM emissions limit. As an
alternative a PM CEMS that meets the requirements of PS–11 may be
used, and EPA is proposing to eliminate the current requirement of using
an opacity monitor. The proposed rule solicits comment on making the use
of a PM CEMS a requirement. The commenter stated that EPA should both
require CEMS and retain the use of opacity monitors.

EPA should abandon the BLD system requirement outlined in the proposed
rule and mandate the use of PM CEMS instead. The agency previously
concluded that PM CEMS is a superior monitoring technology that can be
implemented at a reasonable price. EPA has found that BLD systems,
standing alone, are inadequate to verify compliance and has also found
that COMS operate as a useful check on PM emissions and proper operation
of PM CEMS.

Providing a superior level of compliance assurance is not the only
benefit of PM CEMS. EPA has acknowledged that the assumptions to assure
compliance are fewer and less conservative (direct measure of the
standard is the top of the monitoring hierarchy), CEMS mean facilities
need to monitor only one emissions parameter to assure compliance rather
than multiple operating limits, often relevant to more than one
standard, and that the cost of installing PM CEMS technology is
reasonable.

Response: See response in preamble.

HAP metals monitoring

Comment: One commenter (2638) stated that proven HAP metals monitoring
methodology is now commercially available.

Response: We are aware that multi-metal CEMS have been tested and would
support their use should they become readily available. However, at this
time we do not have sufficient data to set individual metals standards
for this source category, which would be necessary of we were to use
multi-metals CEMS to demonstrate compliance. .In addition, we believe
these systems are not sufficiently demonstrated for this source category
to be the basis of compliance measurement

30-day rolling average compliance period for PM CEMS

Comment: One commenter (2859) recommended that EPA adopt a 30-day
rolling average standard for sources that utilize PM CEMS. Sources that
opt to use an alternative compliance demonstration methodology (stack
testing) would demonstrate compliance by conforming to the relevant test
method.

Response: We agree with the clarification suggested by the commenter and
have added it to the rule.

2.8.5	Impacts

Scrubber performance on PM control

Comment: One commenter (2900) provided stack test data for PM before and
after a wet scrubber was installed. The data shows that the emissions
would still exceed EPA requirements even after optimization of the
scrubber through the last five to six years. The commenter stated that
this scrubber will require some additional equipment or modification in
its operation to achieve the EPA target and it remains uncertain if this
is achievable. However, it can be reported that based on the current
data, it would appear that the emissions were significantly reduced
after installation of the wet scrubber.

Response: Most if not all cement manufacturers are using fabric filters
or electrostatic precipitators in order to reduce PM emissions. We
believe that in order to comply with the final limit for PM for both
existing and new sources, fabric filters using membrane bags will be
required.

Benefits of PM2.5 reductions

Comment: One commenter (2916) stated that EPA should not use a
no-threshold model for estimating the benefits of reducing PM2.5
emissions. EPA’s proposal to adopt a no-threshold model as a part of
this rulemaking will obscure the greater uncertainty associated with
calculated premature mortality at PM concentration levels down to
background (or even below background). The treatment of uncertainty is
one of the key issues associated with conducting benefit/cost analysis.
A number of National Research Council reports have found that the proper
characterization of uncertainty is essential. The commenter recommended
that if EPA adopts a no-threshold model to develop estimates of
mortality, it should present its premature mortality estimates within
concentration ranges and provide a complete discussion of the
uncertainty in the estimates within each concentration range. EPA should
discuss the plausibility and the uncertainties of the estimates within
each concentration category in the body of its analysis and in its
Executive Summary.

Several commenters (2845 and 2849) stated that for the RIA, EPA
abandoned their traditional assumption that there may be a threshold in
the concentration-response function relating exposure to PM2.5 and
premature mortality and EPA should not change its approach on this
important issue until such a shift has been recommended by Clean Air
Scientific Advisory Committee (CASAC) and adopted as final policy. If
EPA were to assume a threshold at 10 ug/m3 as has been done in recent
RIAs, estimated benefits would be some 20–40 percent lower than what
the agency now calculates in the Portland Cement NESHAP RIA.

One commenter (2845) identified the following as serious shortcomings in
EPA’s estimate of benefits that include the following:

EPA has overstated the benefits of PM2.5 reductions by removing the
assumption of a threshold in the dose-response relationship for
premature mortality. This is a significant methodological that deserves
a discussion in the context of the ongoing review of the PM NAAQS,
rather than in the context of a NESHAP for a single industry that is not
even focused on PM2.5. This commenter is concerned that a premature
decision on this issue as a part of this rulemaking will serve as a
precedent for decisions in the PM NAAQS review.

EPA’s use of a no-threshold model in this rulemaking will obscure the
greater uncertainty associated with calculated premature mortality at PM
concentration levels down to or below background. The treatment of
uncertainty is one of the key issues associated with conducting a
benefit/cost analysis.

In setting the NAAQS, EPA has recognized that there is greater
uncertainty in the relationship between the risk of premature mortality
and PM exposure at low concentrations. In the quantitative risk
assessment in the 2006 final rule for the PM NAAQS, EPA presented
several estimates based on different cut points intended as surrogates
for alternative assumed population thresholds. In reviewing the Staff
Paper and risk assessment, the CASAC panel commented that for the
purpose of estimating public health effects, it favored the primary use
of an assumed threshold of 10 ug/m3.

Several factors can contribute to the uncertainty in estimating
premature mortality at low PM concentrations. EPA has generally assumed
either a proportional or quadratic rollback to represent the
effectiveness of control strategies designed to meet the NAAQS, but in
areas with PM levels below 10 ug/m3 there may be little or no change in
air quality. If EPA adopts a no-threshold model, it should address these
several factors in its discussion of the uncertainties in the premature
mortality estimates. Commenter 2845 stated that this discussion on
whether to adopt a no-threshold model and the uncertainties associated
with EPA’s premature mortality estimates should include a separate
discussion for those estimates associated with exposure at lower ambient
concentration levels.

Commenter 2845 noted that EPA had adopted a no-threshold model in the
development of PM benefits for the Tier 2 rule and on-highway heavy duty
diesel engine rules in 1999 and 2001. However, the 2002 National
Research Council report estimating the Public Health Benefits of
Proposed Air Regulations suggested that EPA’s approach in these two
rules failed to provide information on the plausibility of estimates at
different PM concentration levels. The committee suggested that
alternative approaches that reflected expert judgment on the
plausibility of thresholds would have represented an improvement in
EPA’s primary analysis. EPA has recently carried out a multi-year
effort using expert elicitation to assess the relationship between
exposures to fine PM and the incidence of mortality. If EPA adopts a
no-threshold model, EPA should incorporate the results of this study in
presenting its PM benefits analysis for different concentration levels.

Response: The weight of scientific evidence strongly supports modeling
PM-related mortality and morbidity by using concentration-response
functions that do not incorporate an assumed threshold. In 1999, the SAB
Advisory Council on Clean Air Compliance Analysis (ACCACA) concluded
that there was currently no scientific basis for selecting any specific
threshold (EPA-SAB-Council-ADV-99-012). In 2004, the Health and
Environmental Effect subcommittee of ACCACA concluded, “it is
reasonable for EPA to assume a no threshold model down to, at least, the
low end of the concentrations reported in the studies”
(EPA-SAB-COUNCIL-ADV-04-002). In 2005, CASAC indicated that “[t]he
available epidemiological database on daily mortality and morbidity does
not establish either the presence or absence of threshold concentrations
for adverse health effects” (EPA-SAB-CASAC-05-007).

In 2006, EPA conducted an expert elicitation on the relationship between
PM2.5 exposure and premature mortality. Eleven of the twelve experts in
this study did not specify a threshold in their concentration-response
function, whereas one expert specified a 50% probability of
no-threshold, 40% probability of a threshold below 5 µg/m3, and 10%
probability of a threshold between 5 and 10 µg/m3. EPA presents these
expert-derived results in the RIA independently of whether thresholds
are included in the core benefits results or not.

In 2009, the final Integrated Science Assessment for Particulate Matter
indicated that “[o]verall, the studies evaluated further support the
use of a no-threshold log-linear model…” (U.S. EPA, 2009). In 2010,
the Health Effects Subcommittee of the Science Advisory Board “fully
supports EPA’s decision to use a no-threshold model to estimate
mortality reductions. This decision is supported by the data, which are
quite consistent in showing effects down to the lowest measured levels.
Analyses of cohorts using data from more recent years, during which time
PM concentrations have fallen, continue to report strong associations
with mortality. Therefore, there is no evidence to support a truncation
of the CRF ” (EPA-SAB-COUNCIL- -10-001).

Our approach to estimating PM-related health impacts is consistent with
the key findings in these reports. In addition, our approach is
consistent with the on-going PM NAAQS review.

The commenter incorrectly suggests that using a no-threshold
concentration-response function would erroneously model benefits down
to, or below, background. Instead, we applied benefit per ton estimates
that were calculated using previously generated air quality scenarios
projecting air quality changes well above background levels. For the
final analysis, we estimated benefits on the basis of modeled air
quality changes from CAMx, where we again considered air quality changes
well above background levels.

In conjunction with the commenter’s concern, and consistent with
recent scientific advice, we have replaced the previous threshold
sensitivity analysis with a new “lowest measured level” (LML)
assessment. While an LML assessment provides some insight into the level
of uncertainty in the estimated PM mortality benefits, EPA does not view
the LML as a threshold and continues to quantify the PM-related
mortality impacts using the full range of modeled air quality
concentrations. The results of this analysis are provided in Section 6
of the RIA.

2.8.6	Other

PM as surrogate for HAP metals

Comment: Several commenters (2832 and 2859) stated that the use of PM as
a surrogate for HAP metals is an important issue in this proposal;
however, EPA has failed to explain its selection of using PM as a
surrogate for HAP metals and how that approach was applied specifically
to the data in this administrative record. EPA is required to
specifically detail how this approach was used and what other approaches
were taken and rejected and why as part of the Preamble to the proposal.

Response: Use of PM as a surrogate for non-volatile HAP metals – in
this very industry – has already been upheld. See National Lime II,
233 F. 3d at 639.

Comment: One commenter (2638) stated that it is no longer appropriate to
use PM as a surrogate for HAP metals. The commenter provided citations
of studies, and summarized the main points supporting this statement.
The commenter further argued that the courts have questioned whether the
use of PM as a surrogate for HAP metals is scientifically reasonable,
that HAP metals are not invariably present in cement kiln PM, PM control
technology does not indiscriminately capture HAP metals along with other
particulates, and PM control is not the only means by which facilities
achieve reductions in HAP metal emissions.

The commenter stated that direct measurement of HAP metals is essential
for the EPA to comply with the spirit and intent of the Clean Air Act,
and direct measurement of HAP metals is required to evaluate residual
risks.

Response:    The EPA disagrees with the commenter.  We continue to
believe this is an appropriate surrogate.  Particulate matter controls
do in fact capture HAP metals along with other particulate matter, with
the exception of mercury, for which we have set separate emission limits
under this rule making.  We have shown that particulate matter is an
appropriate surrogate for non-volatile metal HAP in numerous previous
rulemakings, including  the NESHAPs for Iron and Steel Foundries (69FR
21912, April 22, 2004) and the NESHAP for Taconite Iron Ore Processing
(68 FR 61885, October 30, 2003).

NESHAP and NSPS PM limits

Comment: Several commenters (2845 and 2874) agreed that if EPA is
proposing PM limits under both the NESHAP and NSPS, the source should
comply with the most stringent emission limit. The commenters suggested
that EPA explicitly exempt the source from complying with all associated
requirements (monitoring, recordkeeping, and reporting) relating to the
less stringent limit, not just from that limit itself.

Response: The standards are now identical.

Volatilized metal HAP emissions

Comment: One commenter (2898) stated that under the high temperature
conditions of the cement kiln non-volatile metal HAP emissions could
occur outside of the particulate form. Therefore, EPA should assess the
emission levels and associated public health threats remaining after
successful implementation of the proposed standard.

Response: EPA already has a mechanism in place for conducting an
assessment of public health threats remaining after implementation of
MACT. The Risk and Technology Review (RTR) is a combined effort to
evaluate both risk and technology as required by the Clean Air Act (CAA)
after the application of maximum achievable control technology (MACT)
standards. Section 112(f) of the CAA requires EPA to complete a Report
to Congress that includes a discussion of methods the EPA would use to
evaluate the risks remaining after the application of MACT standards.
These are known as residual risks. Section 112(f)(2) directs EPA to
conduct risk assessments on each source category subject to MACT
standards, and to determine if additional standards are needed to reduce
residual risks. Section 112(d)(6) of the CAA requires EPA to review and
revise the MACT standards, as necessary (but no less often than every 8
years), taking into account developments in practices, processes and
control technologies.

Thallium

Comment: One commenter (2144) stated that thallium metal (Tl) and its
compounds are highly toxic materials and are emitted from certain cement
plant on the finest dust particles emanating from the stacks. The
commenter stated that concentrations in certain cement filter dusts can
build up to levels greater than 1 percent (10,000 ppm) and that proper
regulation of PM coupled with the required mercury reduction will
concurrently address such Tl concentration buildup and emissions. In the
long run, consider regulation of Tl as a HAP consistent with present
European practice.

Response: Thallium is not currently listed as a hazardous air pollutant
(HAP) under Section 112(b) of the CAA. As such, EPA does not have the
authority to regulate emissions of thallium under the provisions for
establishing MACT standards.

2.9	Compliance Dates

Arbitrary compliance dates

Comment: Many commenters (2832, 2845, 2859, 2863, 2864, 2874, 2890,
2914, and 3193) stated that EPA should follow the intent of the CAA
sections 111 and 112 which established the requirement that new and
existing sources recognized in the proposed rule use the published date
of May 06, 2009, as the new source trigger date for mercury, HCl, and
THC emission standards instead of the proposed retroactive date of
December 2005 when the amendments for mercury, THC, and HCl were first
proposed. The commenters stated that despite the direct acknowledgements
in the proposed rule, EPA arbitrarily decided to apply a proposal date
for mercury, THC and HCl that reaches back and applies new source
standards to any plant constructed since December of 2005 and admitted
that the 2005 proposal did state EPA’s desire to establish floors for
THC, HCl and mercury. According to the commenters, this is irrelevant
because sources constructed in the past four years cannot have
reasonably anticipated their need to comply with the 2009 proposed
floors based on the 2005 proposed rulemaking. The 2005 rulemaking
resulted in a final rule with floors for THC and mercury, and no HCl
floor (due to its classification as a threshold pollutant), which are
significantly different than the 2009 proposal and the 2005 proposal did
not reference a desire to establish a floor for PM, nor one as stringent
as that set forth in the current proposal.

Response: As explained in the preamble, EPA agrees with these comments
and has adopted a May 6, 2009, compliance date for determining when
sources come into existence for purposes of determining which sources
are subject to new source MACT.

Reduced compliance period

Comment: One commenter (2891) disagreed with EPA’s decision to grant 3
years from the date of the rulemaking for existing sources to come into
compliance. Given the serious impacts of these emissions on public
health and the fact that the industry has had ample warning of these
standards, a shorter compliance timetable is reasonable. The commenter
supported a compliance date of no more than 2 years.

The commenter agrees that new sources should comply upon commencement of
operation. The commenter agreed with EPA’s selection of December 5,
2005, as the proper date for determining when a source is deemed to be
new for THC, mercury and HCL. The commenter stated that the
determination for PM ought to be March 24, 1998, which is the date that
EPA first proposed PM restrictions on this sector, and is therefore a
date consistent with the language and intention of the Act.

Response: The commenters do not address EPA’s analysis at proposal
indicating that the phrase “first proposes” in section 112 (a)(4) is
ambiguous, nor other provisions (e.g. sections 112 (i)(2)) indicating
that the phrase is ambiguous. Nor did the commenters address the similar
language in section 111 (a)(2) for NSPS, which has never been
interpreted as stretching back in time for decades to match an initial
proposal date. For the reasons stated in the preamble to the final rule,
EPA believes the proposed date of these amendments is a proper
compliance date for purposes of determining the applicable date for new,
reconstructed, or modified sources.

Comment: One commenter (2898) recommended that EPA consider a faster
timeline for existing sources implementation and to finalize its
proposal on compliance dates for new sources. EPA has proposed to use
the date of December 5, 2005, as the date for determining if a source is
existing or new for the purposes of the mercury, THC, and HCl standards,
and has proposed May 6, 2009, as the relevant date for PM standards. The
commenter supported EPA’s proposed dates as a reasonable
interpretation of the statute’s definition of a new source as a
stationary source the construction or reconstruction of which is
commenced after the Administrator first proposes regulations under this
section establishing an emissions standard applicable to such source. 42
U.S.C. §7412(a)(4). We agree that the statutory definition should be
read to apply pollutant-by-pollutant and to the rulemaking record under
which a standard is developed to avoid subjecting sources in existence
for 10 years to the new standards which they could not have anticipated
at the time. This is consistent with the statute’s structure requiring
more stringent standards for new sources.

Response: As explained in the preamble, EPA has adopted a May 6, 2009,
compliance date for determining when sources come into existence for
purposes of determining which sources are subject to new source MACT.
For the reasons stated in the preamble to the final rule, EPA believes
the proposed date of these amendments is a proper compliance date for
purposes of determining the applicable date for new, reconstructed, or
modified sources.

For existing sources we proposed a compliance date of 3 years after the
promulgation of the new emission limits for mercury, THC, PM, and HCl to
take effect. This is the maximum period allowed by law (subject to a
one-year extension determined on an individualized basis to install
technology). See section 112(i)(3)(A) and (B). We continue to believe a
3 year compliance period is justified because most facilities will have
to install emissions control devices (and in some cases multiple
devices) to comply with the proposed emissions limits. Therefore, we
have retained a 3 year compliance data in this final rule.

For new sources, the compliance date will be the effective date of this
final rule or startup, whichever is later. Because this is a major rule
as defined by the Congressional Review Act, the effective date of the
rule is 60 days after publication of the Federal Register.

In determining the proposal date that determines if a source is existing
or new, we have decided to select the proposal date of these final
amendments, which is May 6, 2009, for all the standards.

At proposal, we considered three possible dates, including March 24,
1998; December 5, 2005; and the proposal date of these final amendments,
which was May 6, 2009. As we noted at proposal, Section 112 (a)(4) of
the Act states that a new source is a stationary source if “the
construction or reconstruction of which is commenced after the
Administrator first proposes regulations under this section establishing
an emissions standard applicable to such source.” “First proposes”
could refer to the date EPA first proposes standards for the source
category as a whole, or could refer to the date the agency first
proposes standards under a particular rulemaking record or first
proposes the particular standards at issue. The definition is also
ambiguous with regard to whether it refers to a standard for the source
as a whole, or to a HAP-specific standard (so that there could be
different new source standards for different HAP which are regulated at
different times). At proposal we chose the date of December 5, 2005, as
the proposal date that determines if a source is new or existing for the
mercury, HCl, and THC, and the May 6, 2009, date for PM.

After consideration of comments on the selection of the date for
mercury, THC, and HCl, we believe that the May 6, 2009, date for all
pollutants is more in keeping with the evident intent of Section 112
(a)(4) that source should have sufficient notice that new source
controls requirements can be considered in the initial design. We accept
commenters’ argument that sources coming into existence between the
proposed date of the 2006 standards and the May 6, 2009, proposal date
of these amendments would have no reasonable means of ascertaining the
standards’ final content and so lacked notice of what controls and
strategies to adopt. Since this is antithetical to the policy underlying
new source standards, EPA is adopting May 6, 2009, as the date which
determines if a source is existing or new.

We note that there are currently sources subject to new source limits
for mercury and THC contained in the December 20, 2006, rule. However,
the mercury the new source standards in this final rule are
significantly different than the limits in the December 20, 2006, rule,
and we do not see how the affected sources could have anticipated this
change prior to proposal of these amendments. Accordingly, we have
selected a date that allows these facilities to design and install the
required control equipment.

 See the preamble discussion under compliance dates for more information
on EPA’s decision.

2.10	Startup, Shutdown, Malfunction (SSM)

Limit emissions during periods of SSM

Comment: Several commenters (2155, 2891, 2895, 2898, and 2911) supported
emissions standards for startup, shutdown, and malfunction equal to
normal operating conditions. Commenter 2155 stated that if less
stringent standards are considered, they should be for only a very short
time period around startup and shutdown. To keep malfunctions at a
minimum, we would not recommend less stringent standards for such
occurrences, lest they become the norm. Commenter 2898 requested EPA to
clarify if it intends to remove the exemption for all sources at cement
facilities and stated that EPA may deviate from the MACT floor standards
only in very limited circumstances. EPA may establish work practice or
operational standards, different than the established MACT floor
standards, only if it is not feasible to prescribe or enforce an
emission standard on the basis of either a design or source-specific
basis.

Response:  EPA is adopting separate standards for startup and shutdown.
These standards are explained in the preamble to the final rule. As
explained in the preamble, the standards for these operating modes is
expressed on a concentration basis (not normalized to production) and
use different averaging periods than the main standards. Malfunctions
may in fact occur, and when malfunctions result in emission that cause
the standard to be exceeded, they can contribute to violations, although
sources have a n affirmative defense to civil penalties if they are able
to establish the affirmative defense set out in 63.1344 of the final
rule.. During malfunctions, sources are also obligated to limit
hazardous emissions to the extent possible, following good engineering
practices protective of safety and the environment.

MACT emission standards for periods of SSM unreasonable

Comment: Many commenters (2832, 2841, 2844, 2845, 2859, 2863, 2887,
2890, 2901, 2916, 2929, and 3218) opposed setting MACT emissions
standards for periods of SSM. The commenters opposed setting MACT
emissions standards or limits that fail to reflect differing processes
and process equipment conditions, including air pollution control and
monitoring equipment, during each of these SSM timeframes. It is
physically impracticable, if not impossible, for the process units in
question to shut down immediately in the event of a malfunction. These
emissions conditions during SSM are not the same as the conditions
during regular or routine operations. Commenter 2887 provided examples
of opacity data collected during SSM events. Commenter 2901 stated that
EPA’s proposed requirement that facilities meet steady-state standards
during SSM events is not lawful, citing decisions previous to the
Court’s decision in Sierra Club v. EPA, 551 F.3d 1019 (DC. Cir 2008)
that held that technology-based standards must contain exemptions or
less stringent standards during SSM periods. The commenter stated that
because all pollution control technologies will occasionally malfunction
and take time to get to their steady-state conditions, achievable
technology-based standards must contain provisions excusing
noncompliance or making compliance easier during such unavoidable
events.

Commenter 2916 stated that EPA knows that emissions during periods of
SSM are likely to be different than emissions during normal operations
but the Agency ignores these facts and, instead, simply points to an
absence of emissions data from SSM periods as a reason to propose that
standards based on data from periods of normal operation are
appropriate. The absence of emissions data creates a duty for the Agency
to gather the data needed to set specific standards for SSM or, if
developing such information is not technically feasible, setting work
practice standards for SSM periods.

One commenter (2844) stated that if EPA applies the proposed emission
limits at the time of SSM events, then such events constitute reasonably
foreseeable operating conditions, and certainly the range of such
events, including their worst impacts on emissions achievements, needs
to be taken into account when estimating the floor units’ emissions
variability achieved in practice.

Response: As discussed in the preamble, EPA has taken into account
cement kilns’ operating properties during startup and shutdown periods
and has established different standards for those periods where
appropriate. Therefore, commenters concerns regarding startup and
shutdown periods have been considered and addressed in the final rule.
For the reasons explained in the preamble to the final rule, EPA is not
setting separate standards for malfunctions and during a malfunction,
the otherwise applicable standard applies. However, as explained in the
preamble to the final rule, in the event that a source fails to comply
with the applicable CAA section 112(d) standards as a result of a
malfunction event, EPA would, of course, determine an appropriate
response based on, among other things, the good faith efforts of the
source to minimize emissions during malfunction periods, including
preventative and corrective actions, as well as root cause analyses to
ascertain and rectify excess emissions. EPA would also consider whether
the source's failure to comply with the CAA section 112(d) standard was,
in fact, “sudden, infrequent, not reasonably preventable” and was
not instead “caused in part by poor maintenance or careless
operation.” 40 C.F.R. § 63.2 (definition of malfunction). See,
Weyerhaeuser v Costle, 590 F.2d 1011, 1058 (D.C. Cir. 1978)( “ In the
nature of things, no general limit, individual permit, or even any upset
provision can anticipate all upset situations. After a certain point,
the transgression of regulatory limits caused by "uncontrollable acts of
third parties," such as strikes, sabotage, operator intoxication or
insanity, and a variety of other eventualities, must be a matter for the
administrative exercise of case-by-case enforcement discretion, not for
specification in advance by regulation.”)

As also discussed in the preamble, in light of comments raising concerns
with EPA’s proposed approach to malfunctions, the final rule includes
an affirmative defense to civil penalties for exceedances of emission
limits that occur during malfunctions. See 40 CFR 63.1341 (defining
“affirmative defense” to mean, in the context of an enforcement
proceeding, a response or defense put forward by a defendant, regarding
which the defendant has the burden of proof, and the merits of which are
independently and objectively evaluated in a judicial or administrative
proceeding.). This approach is not inconsistent with the Pre-Sierra Club
cases, Portland Cement Ass’n v. Ruckelshaus, 486 F.2d 375 (D.C. Cir.
1973) and Essex Chemical Corp. v. Ruckelshaus, 486 F.2d 427 (D.C. Cir.
1973), cited by one commenter. Although the relevance of those cases is
not clear in light of intervening caselaw, EPA’s overall approach to
malfunction events in this rule is consistent with the approach set
forth in EPA’s 1972 proposed rules that were cited favorably in those
decisions in that both “impart a construction of "reasonableness" to
the standards as a whole and adopts a more flexible system of regulation
than can be had by a system devoid of "give." Id. at 399. Those
decisions did not require exemptions or less stringent standards for
malfunction events as the commenter suggests.

EPA’s overall approach to malfunctions is also not inconsistent with
the NRDC v EPA, 859 F. 2d 156, 207(D.C.Cir. 1988) and   HYPERLINK
"http://www.lexis.com/research/xlink?app=00075&view=full&searchtype=get&
search=564+F.2d+1253%2520at%25201272" \o "Clicking this link retrieves
the full text document in another window" \t "x"  Marathon Oil Co. v.
EPA, 564 F.2d 1253, 1272 (9th Cir. 1977)  cases cited by the same
commenter. Although neither case is directly on point and the NRDC
case’s discussion of technology-based standards is dicta, these cases
don’t require exemptions or less stringent standards for malfunctions
either. The regulatory affirmative defense included in today’s final
rule is consistent with Marathon Oil’s holding under the Clean Water
Act that EPA must formalize its approach to upsets. But see,
Weyerhaeuser v Costle, 590 F.2d 1011, 1057-58 (D.C. Cir. 1978)(holding
that an informal approach is adequate).

One commenter maintains that the absence of emissions data creates a
duty for the Agency to gather the data needed to set specific standards
for SSM or, if developing such information is not technically feasible,
setting work practice standards for SSM periods.  However, the statute
permits EPA to use available information and imposes no affirmative duty
to gather information.  Cf. Cement Kiln Recycling Coalition v. EPA, 255
F. 3d at 867.  Consequently, EPA does not accept the commenter’s
suggestion.

Work practice options

Comment: Many commenters (2841, 2844, 2845, 2874, 2887, 2890, 2929, and
3218) stated that EPA should propose either work practice standards as a
viable alternative to the current ongoing SSM litigation (General
Provisions, 40 CFR 63) or suspend efforts to establish SSM limits
during this rulemaking and consider a separate regulation. According to
the commenters, work practices would be appropriate given the
technological and economic limitation involved with applying a valid
measurement method. Commenters 2841, 2844, and 2845 included a work
practice plan suggestions and a sample SSM outline and plan as part of
their comments. As an alternative, EPA should initial a separate
rulemaking effort to address SSM emissions once more information on SSM
emission is available. Reasons stated for a work practice standard
include the following:

EPA, in setting a MACT floor, must take into account the variability of
the best performing source by including emissions during periods of SSM.

The proposed compliance requirement means that mercury emission cannot
be practically measured during SSM.

Accurate quantification of the mass of mercury emitted per million tons
of clinker produced cannot be assured during SSM.

During SSM, low kiln feed which in turn causes clinker production to be
very low will reduce mercury emission levels to the point they are below
the point of accurate measurement.

During startup, mercury emissions are divided by a very small clinker
production rate leading to increased mercury emission rates per unit.

Also during startup, it is anticipated that mercury emission rates will
spike as ductwork heats and any absorbed mercury compounds are released
or due to other transient affects.

During shutdown, kiln feed and clinker production is decreasing to zero
and mercury emissions are greatly exaggerated which also leads to
increased errors of mercury rates per unit.

Units equipped with wet scrubber or activated carbon control devices are
not operated during startup until specified kiln operating parameters
are met in order to protect the control device from damage and therefore
active controls are not functioning during the start-up and shut-down
period for some kilns.

For mercury CEMS used in the electric utility industry, during SSM, the
sample gas molecular weight changes due to the reduction in CO2
concentrations which affects the accuracy of mercury measurements.

For HCl and THC, changes in moisture and oxygen concentration, kiln
volumetric flow rate, kiln feed, and fuel firing will result in
unreliable emissions measurements.

PM CEMS monitoring data will not accurately reflect actual emission
during SSM because of technical difficulties, and excessive testing
costs; stability of the PM CEMS; and affects on CEMS operations due to
differences in fuels burned, firing rate, and feed rate.

Response: The commenters indicated that certain features of the
standards could not be measured (those which are normalized to
production), but not that the HAP itself was incapable of measurement.
Thus, EPA does not see that the criteria of section 112 (h) have been
satisfied here. The standards in the final rule are not normalized to
production for the reasons provided in the public comments.  SSM
conditions should not be contained in correlation tests because they are
usually short lived, and erratic and probably not repeatable. that the
correlation is developed under normal operating conditions because that
is typical of the majority of time and SSM emissions are then quantified
based on that correlation

Comment: One commenter (2845) stated that EPA should address SSM through
the use of work practice standards that include:

Preventive maintenance activities intended to minimize malfunctions and
unplanned shutdowns of air emissions control systems

Procedures to be followed to minimize HAP emissions during kiln startup
and during planned shutdowns

Procedures for detecting and remedying malfunctions that result in
excess emissions that include a determination of the cause and
corrective actions.

The commenter has provided a sample SSM plan as an attachment to their
submitted comment.

Response: See previous response.

Consideration of SSM in mercury standards

Comment: Several commenters (2845 and 2855) stated that EPA’s 30-day
rolling average limit for mercury does not consider the periodic
maintenance shutdown of the raw mill. The raw mill is generally shut off
for scheduled maintenance about 15 percent of the time. However, there
are times where unscheduled shutdowns do occur. In addition, the raw
mill operation is interrupted when feed storage silos are full.
Depending on the specific plant, the mill downtime could have a major
impact on the average emission during that period. This will have an
impact on mercury emissions during that month, resulting in substantial
outliers in the 30-day data sets. To ensure these outliers do not result
in the facility being out of compliance for the proposed rule, any
mercury control strategy to be considered by the plant would need to
take this possibility into account. As a result, the cost of the mercury
control strategy is greater than would be the case if these types of
maintenance issues did not occur. An alternative that could be
considered by EPA would be to provide some form of exception for
shut-down, maintenance, and start-up.

Response: The comment does not give EPA a sufficient view of the
predicament faced by the source to indicate that compliance during
startup, normal operation, and shutdown periods is impracticable. In
fact, the description of the scenario presented by the commenter leaves
ample room for the Agency to interpret that compliance depends on
source-specific conditions, operator discretion, and a variability in
emissions with indeterminate causes among shutdown and restart events.
For instance, an unscheduled shutdown may or may not share the emissions
profile of a scheduled shutdown. A prior comment alluded to
“impracticable immediate shutdowns.” Given the averaging periods
built into the standard which accommodate spikes, and the generally less
challenging conditions obtaining during startup and shutdown conditions
(when less mercury-containing material is input to the kiln), EPA does
not accept, in the absence of any data, that unscheduled shutdowns,
impracticable immediate shutdowns, and scheduled shutdowns all, somehow,
make compliance impossible.

Clarifications, corrections

Comment: One commenter (2845) stated that §63.1342 indicates that
63.6(f)(1) Compliance with Emission Standards, is not applicable to
Subpart LLL. If this is the case, §63.6(e)(3) Startup, Shutdown
Malfunction Plans, should not be applicable as the SSMP provisions are
no longer needed if the facility cannot utilize the SSM exemption
provided for in Subpart A. The commenter suggested that in Table 1 to
subpart LLL of Part 63 – Applicability of General Provisions,
63.6(e)(3) Startup, Shutdown Malfunction Plan will not be applicable to
subpart LLL.

Response: The EPA agrees that if a source may no longer avail themselves
of an exemption for startup, shutdown, or malfunction, then a startup,
shutdown, and malfunction plan is no longer necessary. The applicability
of the requirement to have an SSM plan has been deleted.  .

Emission standards and SSM exemptions

Comment: One commenter (2846) disagreed with EPA’s proposal to not
apply the SSM exemptions to the emissions standards in this proposed
rule. The commenter provided two options to address emissions during SSM
events:

SSM emissions could be treated as de minimis emissions; and

EPA needs to establish work practice or operational standards that would
apply during SSM periods.

Response: See preamble to final rule and earlier responses as to why no
showing has yet been made as to why work practice standards are
permissible here.

Area sources

Comment: One commenter (2887) stated that with respect to area sources,
the EPA could utilize its discretion under §112(d)(5) to impose
management practices to limit emissions during SSM events.

Response: EPA interprets management practices to mean actions homologous
to work practice standards. See the preamble to the final rule and
earlier responses as to why no showing has yet been made as to why work
practice standards are permissible here.

Continuous monitoring of PM and vapor phases of all HAP metals

Comment: One commenter (2638) stated that with the inclusion of SSM
emissions subject to the standards, PM and vapor phases of all HAP
metals including mercury should be continuously monitored. CEMS would be
required to measure emissions during randomly occurring malfunction
events. PM is not expected to be a good surrogate for HAP metals during
SSM events in which emissions, control of these emissions, the chemical
state of the emissions and the partitioning between phases could and in
realistic circumstances would be expected to be different from those
during normal operation.

The use of multi-metal CEMS methods would allow all of the urban HAP
metals including mercury and all phases to be continuously monitored
with a single CEMS. This option would be simpler, more reliable and have
lower initial and on-going costs than the only other option consisting
of two CEMS, one for PM and one for mercury vapor.

Commenter 2638 recommended that SSM events be included in the standard,
and that HAP metals emissions be monitored using CEMS.

Response: EPA sees no reason to believe that the surrogacy relationship
would be altered by startup, shutdown or malfunction events.

Use of PM as a surrogate for non-volatile HAP metals – in this very
industry – has already been upheld. See National Lime II, 233 F. 3d at
639. See the preamble discussion under final testing and monitoring
requirements for more information.

2.11	Economic Impacts

Control technology performance uncertainties

Comment: In order to estimate the economic impact of the proposed rule,
commenter 2845 examined the need for controls and the likely controls
and identified the following as issues with the level of performance
that each emissions control technology will achieve when applied to meet
the proposed standards (additional details are presented in Appendix 12
of the commenter’s submittal):

There is only one kiln with an RTO and we do not know how well an RTO
will work on kilns with differing profiles of organic emissions.

It was assumed that wet scrubbers will reduce HCl emissions in the
presence of high SO2 levels but there are technical concerns with the
successful control of HCl in that circumstance.

No one has applied activated carbon to a kiln exhaust to achieve either
the THC or the mercury control levels needed to comply with this
standard. In addition, there is an expectation that a single carbon
system can control both mercury and THC but that has not been
demonstrated. At present, carbon systems for THC are designed
differently from systems for mercury.

Wet scrubber performance in controlling mercury is variable and some of
the mercury captured is reemitted as operating modes change. There is
evidence that some units will gain very little mercury control with a
scrubber due to the form of the mercury in their exhaust.

There is strong evidence that RTO are not capable of reducing emissions
to below the proposed THC standards.

There is significant uncertainty as to whether a wet scrubber can reduce
HCl levels to below the proposed HCl standards.

Not all kiln locations have the natural gas service needed to fire an
RTO.

Not all kiln locations will have access to the water needed to operate a
wet scrubber.

Commenter 2845 stated that there are key uncertainties associated with
the control performance assumptions used by EPA but in order to develop
their own analysis of the cost of controls, has developed its own
control performance assumptions:

An RTO will cut THC emissions by 95 percent and a scrubber will precede
the RTO. Doubts that an RTO can be operated consistently below 7 ppm of
THC without regard for the starting concentration due to the THC
associated with the combustion of the natural gas and the emissions
during switching of the thermal beds. The commenter assumes for their
analysis that RTO will be able to consistently reduce emissions below
the 7 ppm limit even though the one commercial application of an RTO on
a kiln has not done so.

A scrubber will control mercury, on average, by 50 percent. It is clear
that actual performance is a function of the mix of oxidized and
elemental mercury which can be highly variable.

Any ACI system will used to control both mercury and THC. ACI will
reduce organics by 50 percent due to their poor performance in
adsorbing light hydrocarbons. Any ACI system will include a dedicated
bag house to capture the carbon ladened dust. That bag house will be
50-66 percent of the size of a new bag. ACI with a bag filter will
reduce mercury emissions by 75 percent.

A unit that adds both ACI, with a bag house, and a scrubber is assumed
to have overall mercury control of about 85 percent.

The new PM standard will require that all units have a bag house. For
this analysis, the exact performance of the bag house is not addressed
but simply it is assumed that all kilns must have one. However, if a
unit has an ESP and adds ACI with a bag house, it is assumed that the
existing ESP will not need to be replaced.

To the extent a unit has baseline stack test HCl emissions over the
standard, it is assumed that a wet scrubber will be needed. The exact
performance of the scrubber is not known.

Another compliance requirement that will need to be consider for its
cost will the installation and operation of CEMS for THC, HCl and
mercury for each regulated stack.

Scrubbers installed to meet the limits under this rule will reduce SO2
to some degree. To assess that impact, we have surveyed scrubber
suppliers and test data and developed the following assumptions:
scrubbers will provide between 90 percent and 95 percent control for SO2
but will not control below 15 ppm of SO2.

Response: EPA is aware that the actual performance of any control device
will depend on a number of factors and will likely vary to some unknown
degree among kilns. EPA made based its estimates of performance on
available performance data including data for the cement industry as
well as other relevant industries. In some cases that data were limited.
For example, EPA’s estimate of scrubber performance for wet scrubbers
on mercury emissions was based on the test conducted at 5 kilns. ACI
performance was based on the experience of the utility industry, as well
as a pilot test conducted at one portland cement kiln. In estimating
cost impacts and emission reductions, we calculated the removal
efficiency that would be required to comply with the final limits and
assigned a control device based on the reduction that would be
necessary. The cost impacts are conservative in that for every kiln, we
assumed that one or more control devices would have to be added. We
believe that we have overstated what actual costs will be for the
industry. While we may not accurately predict the controls that each
kiln will eventually install to comply, we have provided an estimated
cost of compliance and accounted for the fact that the emission limits
will require expenditures by the industry to comply. The actual cost
associated with compliance is not factored in the decision of what the
level of the standard should be. EPA must set the standards based on the
best performers, regardless of the means by which they are the best
performers.

The commenter took issue with the controls and level of performance used
by EPA in its analysis of impacts. Regarding the ability of RTO to
adequately control organic emissions, a currently operating RTO with
several years of operating experience is controlling THC on a long-term
basis to an average of about 5 ppmvd at 7 percent O2 measured as
propane. Furthermore, as a result of additional long-term THC data
received after proposal, EPA has increased the THC limit to 24 ppm for
promulgation. In addition, sources have the option of complying with the
alternative limit for organic HAP. We acknowledge that a few sources may
find it necessary to add RTO because of the level of control necessary,
although we believe that most kilns can be adequately controlled using
ACI systems that get an estimated 50 percent control of THC (due to the
presence of lighter hydrocarbons such as methane and ethane that are not
as effectively removed by RTO as heavier compounds) and an estimated 80
percent control of other organic HAP. Where RTO are installed, they will
be expensive, due in part to the fact that the RTO must be preceded with
a wet scrubber in order to remove SO2 that can foul the RTO. However, we
have found that only 10 kilns nationwide may need to install RTO.

We also agree with the commenter that RTO use may not be feasible in
areas that lack access to natural gas supplies. However, as stated
above, the number of sites where we expect RTO to be necessary is
limited. Based on information available at the U.S. Energy Information
Administration, all six states where kilns potentially needing RTO are
located appear to have access to natural gas. We do not believe that
water availability will be a limiting condition in these locations.

The commenter had concerns about the ability of wet scrubbers to remove
HCl in the presence of SO2. We agree that the wet scrubbers currently on
U.S. cement plants are designed to remove SO2, rather than HCl. However,
an EPA review of HCl emissions from 21 plants indicated an average HCl
concentration of 12 ppm, and a maximum HCl concentration of 55 ppm.
Therefore, required HCl removal efficiencies to meet the 3 ppm emissions
standard are expected to be much lower than 99 percent for virtually all
kilns. A preliminary review of data gathered from a 2010 Information
Collection Request (ICR) for Electrical Generating Units indicates that
wet scrubbers utilizing lime will be able to provide the necessary
collection efficiency to meet the 3 ppm emissions standard.

EPA believes the commenter’s concern over the performance of ACI
systems are not well–founded, based on the experience with the use of
ACI systems for both mercury and organic emission controls in other
industries, including medical waste incineration and coal fired boilers.
The ACI system installed at Ash Grove in Durkee, OR is expected to
achieve over 80 percent reduction in mercury emissions. Based on pilot
tests, removal efficiencies of over 90 percent were achieved, depending
on the type of carbon and the injection rate.

As noted by the commenter, scrubber performance on mercury can be
variable and depends on several factors, such as the mercury species
present, the presence of chlorine in exhaust gases, and the liquid
injection rates. Tests conducted on the scrubbers currently in use in
the cement industry showed removal efficiencies from 50 percent for one
scrubber to over 80 percent at two scrubbers. These removal efficiencies
were the average of tests conducted during raw mill on and raw mill off
conditions. Usually during the raw mill off period, removal efficiencies
are higher, due to the presence of greater concentrations of oxidized
mercury than during the raw mill on phase, when most of the mercury is
in the elemental phase. We agree that wet scrubbers may not perform as
well as ACI systems on mercury, and we believe that ACI systems, which
have higher removal efficiencies and are less expensive to install and
operate than scrubbers, will be the predominant control method used. Our
impact and economic analyses are based on this assumption.

Where both ACI and wet scrubbers are installed, the combined efficiency
of the two systems on mercury control will vary. We expect that ACI
systems with removal efficiencies of 80 percent or better will remove
most of the mercury and that, where mercury concentrations in the
exhaust gas stream are low to moderate, wet scrubbers will not impact
final mercury emissions significantly. Our impacts analysis uses this
assumption. However, in situations involving high mercury
concentrations, we believe that scrubbers after ACI systems will have
significant impacts on the final emissions. In our analysis, this was a
factor for only two kilns that have extremely high mercury emissions.

We agree with the commenter’s statements that, where a facility
currently operates an ESP and is expected to install an ACI system
(including polishing baghouse), in most instances they would not need to
replace their ESP. Our impacts analysis uses this approach. We also
considered the costs of CEMS in our analysis as suggested by the
commenter.

Regarding the commenter’s statement that scrubbers will not control
SO2 below 15 ppm, outlet test data from one cement plant report SO2
levels well below the 15 ppm level. (Memo, Bahner, Laney, Barnett,
Summary of Cement Kiln Wet Scrubber and Lime Injection Design and
Performance Data, May 29, 2008, Docket EPA-HQ-OAR-2007-0877)

Comment: One commenter (2891) stated that the goal of MACT standards in
general is to achieve 90 percent or better reductions in the targeted
hazardous air pollutant emissions. Some estimates place the likely
reductions from this proposed regulation as low as the low to mid-80
percentile for reduction. If that is correct, the commenter requested
that EPA describe in plain terms the Agency’s justification for
obtaining reductions below 90 percent.

Response:  MACT standards must be of minimum stringency reflecting
performance which is the average of a select group of best performers,
or the performance of the best-controlled similar source, and may be
more stringent. There is no specific emission reduction percentage,
however, which constitutes MACT.

Alternate impact analysis

Comment: One commenter (2845), in estimating the impacts of the proposed
rule, stated that there was insufficient data to perform a kiln-by-kiln
analysis of controls. Instead they used available emissions data for
subsets of kilns and extrapolated to the total population assuming 170
kilns needing to comply. In order to estimate the total number of RTO,
scrubbers, ACI, and bag filters needed to comply with the proposed
limits, the commenter listed the steps taken to profile the entire
population of kilns (see Appendix 12 to the commenter’s submittal for
details).

One of the key differences between EPA’s assessment and the
commenter’s assessment is that the commenter expects a larger number
of RTO because of the limited performance of activated carbon on
controlling light hydrocarbons and the need to design the carbon system
to control both mercury and THC. According to the commenter, a number of
kilns will be at risk of non-compliance even with the installation of
the best available controls.

The commenter (2845) took issue with EPA’s assumption of a substantial
secondary benefit in the form of SO2 reductions from the installation of
wet scrubbers under this rule. The commenter stated that there is
significant uncertainty about the nature of a scrubber designed to
reduce HCl or mercury or both and whether it will operate in a manner
that provides the same level of SO2 control as a dedicated SO2 scrubber.
To assess the impact of wet scrubbers on SO2 emissions, the commenter
used the SO2 emissions from the ISIS model and average flow volumes to
calculate the stack outlet SO2 concentration in ppm for each kiln. The
commenter then calculated the control efficiencies that would be
required and control efficiencies that could be achieved for each kiln
assuming that the lowest achievable scrubber outlet concentration of SO2
is 15 ppm based on communications with a scrubber vendor. The commenter
estimated SO2 control ranging from 72-78 percent over the entire SO2
inventory.

One commenter (2845) did not agree with EPA’s assumptions for control
technology effectiveness impacts, controlled emissions estimates, and
costs for installing/operating the various control technologies and are
listed as follows:

The costs for limestone wet scrubbers as estimated using EPA’s (ISIS)
model and production assumptions were compared with best available
control technology (BACT)/best available retrofit technology (BART) cost
calculations using site-specific gas flow and SO2 concentrations for
these same facilities. The results of the comparison of the two methods
can be summarized as follows:

The capital and annual cost projections using the BACT/BART cost
estimates were several times greater than those calculated by EPA.

The SO2 concentration in the kiln gas and the presence of contaminants
in the synthetic gypsum (syngyp) produced will determine whether a
gypsum credit or a sludge disposal cost will be incurred for the
scrubber sludge. The ISIS model always assigns a credit, and the
BACT/BART analysis assigns a cost for disposal. These costs/credits will
be site-specific.

Two key capital and operating costs that are not included in EPA’s
cost analysis are a limestone preparation plant to grind limestone to
the fineness required for the LWS and the handling equipment used to
handle the syngyp created by the LWS. The syngyp has high moisture
content and cannot be handled by the equipment utilized to handle
natural gypsum. The additional costs for these two systems were provided
by the commenter.

Other observed discrepancies impacting annual variable costs include
costs for natural gypsum and costs for onsite or offsite wastewater
treatment. If onsite treatment is utilized, additional capital costs
must also be included.

The ISIS model does not include the potential for additional capital
costs at those plants that will require the kiln ID fan to be replaced.
This is particularly likely where other control devices such as an RTO
or ACI are also required by the new NESHAP requirements. The need for a
new ID fan will be site-specific.

Response: As a result of comments, we examined our costs (including
scrubber costs) and made several adjustments, including revisions to the
exhaust gas flow rates, power demand, and water usage. As an
illustration of the effects of these revisions, at proposal, the capital
cost for a 1.2 million tpy kiln was $9.3 million; the revised estimate
is $25 million. Annualized costs increased from $1.6 to $3.6 million.
Earlier responses in this section address other issues raised by the
commenter.

Comment: One commenter (2844) stated that the exhaust flow rates
reported and utilized in the cost of control section underestimates the
exhaust flow rates to be controlled by using inconsistent factors,
missing certain sources of flow, and using dry instead of actual (wet)
flow rates in the analysis.

Response: In response to this comment, EPA investigated its gas flow
rate estimating approach. Upon looking at additional data that had been
supplied by industry, it did appear that stack gas flow rates generally
exceed the original flow rates used. From the data, it appears that
other sources of gas flow dilute the kiln exhaust and increase the total
flow rate beyond what is expected at the kiln exit. Based on a review of
the additional data and review of operating cost estimates specifically
for scrubbers, changes were made in the operating cost equations.
Changes in the exhaust gas flow rates also affected costs of all control
equipment costs as equipment costs are generally a function of exhaust
gas flow rates. The details of this analysis of exhaust gas flow rates
and changes in operating cost equations is documented in memorandum from
Staudt, Andover Technology Partners, to Srivastava, Torres, Barnett, US
EPA, “RE: Wet Scrubber Cost Algorithms,” February 26, 2010.

Comment: One commenter (2844) stated that EPA’s analysis confuses
capacity of a plant and the actual production of a plant. This approach
overstates the emissions, and understates the control needs and costs.

Response: In our analysis, we chose capacity because actual production
can vary substantially over time. We disagree with the commenter’s
assertion that using capacity maximizes emissions and costs.

Comment: One commenter (2844) stated that for concentration-based
limits, EPA unreasonably assumes that exhaust is at 7 percent oxygen
when sizing and costing out controls. Higher oxygen levels occur in kiln
exhaust due to others sources of flow to the kiln stack. As a result,
the overall flow to the stack will be greater than has been assumed in
the EPA cost analysis. With higher flow will come larger control systems
and added cost.

Response: As noted in a previous response, as a result of comments, we
investigated our gas flow rate estimating approach and made changes that
affected the control equipment costs. The details of this analysis of
exhaust gas flow rates and changes in operating cost equations are
documented in a memorandum from Staudt, Andover Technology Partners, to
Srivastava, Torres, Barnett, US EPA, “RE: Wet Scrubber Cost
Algorithms,” February 26, 2010.

Comment: One commenter (2844) stated that in the assessment of HCl and
THC impacts, EPA assumes each kiln is running at full capacity 365 days
per year, which is impossible. A more reasonable number for days of
operation is 330 days.

Response: EPA assumes 330 days of operation in the cost and impacts
analysis.

Comment: One commenter (2844) stated that scrubber power demand is
presented at 3kWh/ton clinker, which is too low. There appears to be a
minor error in the calculation that is done in converting units but the
main problem is that duct work pressure drop has not been accounted for
and the exhaust flow is too low. Thus, in Section 2.3.5 secondary
impacts are based on unreasonable assumptions. The commenter provided
examples of power costs that are higher than those assumed in EPA’s
assessment.

Response: As noted in a previous comment, as a result of comments, we
examined our scrubber costs and made several adjustments, including
revisions to the power demand, resulting in a change in our control cost
estimates.

Comment: One commenter (2844) stated that other environmental impacts
(Sections 2.4 and 2.5) include errors. The commenter provided a list of
specific errors in the evaluation of other environmental impacts:

Scrubber make-up water is given as 30 gal/ton clinker. In NSPS
rulemaking, however, it was given as 105 gpm for a 1,200,000 tpy plant,
i.e. 42 gal/ton clinker (see EPA-HQOAR-2007-0877-0008, table 9, p.17),
which is 12 gallons more than the new number.

ACI solid waste is given as 3 lb/ton clinker in Exhibit 7 but later a
figure of 6 lb/ton clinker is given.

Scrubber solid waste is omitted. It is assumed by EPA that all the
scrubber waste can be incorporated into cement, but EPA has not
demonstrated that this can be done while meeting product standards.

EPA assumes that CKD can also be incorporated into the cement but EPA
has not demonstrated that this can be done while meeting product
standards.

Response: As noted in a previous response, we examined our scrubber
costs in response to comments and made several adjustments, including
scrubber water usage, resulting in a change in our estimates. In
response to this comment, we have corrected our ACI solid waste estimate
in section 2.5 to indicate 3 lb/ton clinker, consistent with the
estimate provided in Exhibit 7. Our assumption regarding scrubber solid
waste was based on a discussion with plant personnel, who indicated that
scrubber slurry is dried and added to the clinker as gypsum.

Comment: The following are comments from commenter 2845 regarding
EPA’s determination of costs associated with the installation and
operation of ACI for the control of mercury and THC:

A more refined economic analysis performed for an ACI system with a
polishing baghouse resulted in a capital cost factor of $13.33 per ton
clinker and an annual cost factor of $3.91 per ton clinker, both of
which are more than four times the values used by EPA.

The estimated levels of emissions control for ACI used by EPA are overly
optimistic; achievable industry average levels of control for ACI would
be 50 percent for THC and 75 percent for mercury. Depending upon the
form of mercury in the exhaust gases, an ACI system used in conjunction
with a wet scrubber is expected to provide a combined control efficiency
for mercury of 85 percent.

EPA overestimated the amount of solid waste generated from ACI systems.
Based on the vendor-suggested injection rate of 12 lbs activated carbon
per million (actual cubic feet per minute [ACFM]), an ACI system will
generate approximately 1.68 lbs solid waste/ton clinker versus EPA’s
estimate of 3 lbs/ton.

Response: Without any supporting data from the commenter to substantiate
their estimates for ACI costs, mercury emission reductions, and ACI
solid waste, we are unable to evaluate the commenter’s assertions. We
estimated the costs of using an ACI system and polishing baghouse to
control mercury emissions from cement kilns using control costs recently
developed for actual electric utility boilers with exhaust gas flow
rates comparable to those for cement kilns. We estimated the mercury
emissions control based on testing conducted on an ACI system at a
cement plant, which showed mercury removal efficiencies over 80 percent
at carbon injection rates of 10 lbs per million acf. The ACI solid waste
estimates were based on data provided in Docket item II-B-67, Docket
A-92-53.

Comment: One commenter (2845) provided the following comments regarding
EPA’s determination of costs associated with RTO systems for control
of THC.

The pollutant control matrix shown in ISIS incorrectly lists PM,
mercury, and HCl as pollutants addressed by the RTO control option

EPA derived a capital cost factor of $9,598 per dscfm0.6 to estimate the
capital cost of installing an RTO system on a cement plant from
information available on the only currently operating existing
installation within the cement industry. However, the correlation
required flow in dscfm, and EPA used flow in units of standard cubic
feet per minute (scfm), which includes moisture in the gas stream
resulting in a substantial level of error for EPA’s estimation.

To estimate annual operating costs, EPA utilized an empirical formula
with several variables, some of which are dependent upon kiln type.
Based on the information used as EPA’s basis, the empirical formula
vastly underestimates the annual operating cost of the RTO system. The
typical annual maintenance materials costs for an RTO system would be
around $503,000 per year for the 1.2 million ton per year example
facility.

Using a more recent quote from the vendor for an existing RTO a
projected capital cost factor of $11,034 per dscfm0.6, which is about 15
percent greater than that utilized by EPA was estimated for a 1.2
million tpy kiln. The analysis projected an annual operating cost for an
RTO on a precalciner kiln of $4,574,531 as opposed to EPA’s estimate
of $1,199,996, over four times that estimated by EPA.

The estimated levels of emissions control for the RTO used by EPA are
overly optimistic. Recommended, and achievable, industry average levels
of control for an RTO would be 95% for THC although an RTO system is not
capable of maintaining a THC emission level below 10 ppm. Therefore,
many kiln systems with elevated, but not extreme, levels of THC in the
exhaust would not be able to comply with the proposed standard of 7 ppm
through installation of an RTO system.

EPA underestimated the electrical power and natural gas fuel
requirements for RTO systems. Based on a manufacturer’s quote, the
power demand is 46.7 kWh/dscfm and the natural gas requirement is 1.26
million British thermal units (MMbtu)/dscfm. EPA’s estimates were 30.9
and 0.73, respectively.

EPA underestimated the amount of secondary impact emissions from
operating the RTO systems due to the underestimated power demand and
fuel requirements for the installations.

Response: EPA acknowledges commenters’ input regarding RTO control
costs. However, EPA expects 10 or fewer RTO’s to be installed as a
result of this rulemaking. Further refinements to the RTO costs would
not change the underlying MACT floor determinations or emissions
standards. Revised RTO costs may change the estimated cost burden to the
industry, but RTO costs are expected to be relatively small in relation
to the total control costs to the industry.

Comment: One commenter (2916) stated that EPA should consider indirect
effects of the Cement Kiln NESHAP, including increased energy
consumption, increased water consumption, and increased dependence on
foreign supplies of a strategic commodity. The commenter suggests that
the EPA inadequately addresses these indirect effects when explaining
the justification for the MACT standards set in the proposed Cement Kiln
NESHAP.

Response: In considering whether to adopt beyond the floor standards,
EPA did take notice that additional controls would necessitate more
energy use, and could lead to increased water usage and waste
generation. These are additional reasons for not adopting beyond the
floor standards (along with high costs for limited reductions with
consequent poor cost effectiveness). EPA does not consider non-air
quality impacts at the floor to be so extreme as to invalidate what
otherwise is best performance, however.

Comment: One commenter (2916) provided the following cost issues
comments regarding EPA’s determination of costs associated with
installation and operation of baghouses and membrane bags:

Based upon information received from National Cement on a recent
baghouse installation, the commenter believes that capital costs for
baghouses have been understated by EPA by nearly a factor of two.

The pollutant control matrix shown in ISIS incorrectly indicates HCl and
THC being associated pollutants for the baghouse membrane bag (BHMB) and
membrane bag (MBR) control options.

In the monitoring cost section for PM, it is stated that the CEMS Cost
Model assumes each baghouse has 5 compartments which seems off by a
factor of probably 2 or more and raises a question as to the size of the
baghouse EPA has assumed would be necessary for the kilns. In fact, EPA
assumes that the clinker cooler baghouse has the same number of
compartments as the kiln baghouse. Kiln baghouses are usually at least
50 percent larger than cooler baghouses, depending upon the type of
cement process.

EPA assumes that an existing baghouse would need a simple bag
replacement to comply with the PM limit and assumes that the costs to
replace only membrane bags is the difference in cost between the new
reverse air baghouse with fabric bags and a new baghouse with membrane
bags. Many older baghouses will need major repairs/retrofitting or even
outright replacement to use newer membrane bags and still meet the PM
standard. The number of facilities that would fit this category and the
cost to repairs/retrofit on a per facility basis is unknown. EPA’s
cost estimate assumes reverse air baghouses would be the standard
replacement, but most new baghouses on kiln systems are pulse-jet, which
may have higher costs than what EPA assumes.

For PM, EPA used their Air Pollution Control Cost Manual Sixth. The
background documents contain no information on what assumptions EPA used
to generate the costs.. Without the detailed background information on
the specifics of the size and other details regarding the particulate
control device used for the cost estimate, it is impossible to know if
the cost estimates are representative of real world installations or
whether the size of the baghouse used by EPA was based upon ACFM or
scfm, or, if it was based upon scfm, what assumed operating temperature
was used. There are additional costs associated with membrane bags as
follows:

Higher cost of membrane bags (same area as conventional bags).

In most cases, lower emissions will also require lower air to cloth
ratios to limit cleaning and emissions.

Reduced bag life to avoid operating with failed bags.

Response: First, it should be noted that the final rule is not requiring
bag leak detectors, but PM CEMS. Second, in our cost analysis, we used
the reverse-air baghouse design as the basis for our costs in order to
be conservative, based on our understanding that reverse-air designs
would be more expensive than pulse-jet designs. Third, the OAQPS Control
Cost Manual has been the standard reference used by EPA in costing
emissions control equipment, where actual applicable cost data are
unavailable. We assumed membrane bags were about four times more
expensive than standard bags. We used vendor information regarding the
superior performance and life of bags.

Comment: One commenter (2844) stated that Section 2.7 includes error in
the evaluation of cost impacts in the environmental analysis:

Andover 2008a at p27 provides figures for gypsum produced. In a wet
scrubber it is not plaster (or anhydrite CaSO4 M=136) that is made, but
bihydrated gypsum (CaSO4.2H2O M= 172). In addition, that gypsum is wet
(about 12%). So, 64 tons of SO2 removed should make 172*1.12 = 193 tons
of gypsum.

Capital cost for ACI seems very low ($2.41/ton clinker) based on the
commenter’s discussions with vendors.

Response: As noted previously, wet scrubber costs have been revised
based on comments received.

Comment: One commenter (2845) provided the following comments concerning
the CEMS cost modeling approach:

The commenter will need access to EPA’s completed cost model to fully
assess EPA’s assumptions.

The useful life of CEMS for purposes of estimating annualized costs is
unclear and confusing in the EPA background documents.

All costs should be expressed in 2005 dollars for ISIS and for EPA’s
other cost and benefits estimates for the NESHAP. However, it appears
that the CO CEMS costs (that EPA evidently uses to represent costs for
THC CEMS in the NESHAP costing) was completed using 2003 dollars. Based
on the documentation, the commenter cannot determine for what year the
CEMS Cost Model provides costs.

It is anticipated that every facility will need to install a new CEMS
building; even if a building already exists, location issues associated
with the new control technology will dictate that a new building be
constructed. Also, all new CEMS for mercury and other pollutants are
built at the manufacturer or integrator place of business and shipped in
the shelter as a unit. The cost for on-site assembly is prohibitive and
greatly diminishes quality.

Commenter 2845 has more specific CEMS System Comments for mercury, HCl,
THC, and BLD as follows:

For mercury CEMS,

It is expected that the capital cost for purchase and installation of a
single mercury CEMS is in the range of $300,000 – $500,000. The
initial testing for certification adds $35,000.

The extra elemental mercury calibration gas generator that is needed to
meet the QA criteria in the recently published EPA Traceability
Protocols for Elemental Gas Generators is estimated to cost $45,000.
This field reference calibrator could be used to QA generators at
multiple plants.

Upgrades to plant compressed air systems are required for the nitrogen
dilution systems (most widely used Thermo systems).

Using an average capital cost of $500,000 for contemporary mercury CEMS
is more realistic.

Mercury CEMS on-going operation and QA will require one dedicated plant
person per mercury CEMS.

The annual cost to perform the required RATA is $25,000.

The vendor supported maintenance agreement is estimated to cost
approximately $30,000 per system.

Although, the useful life of the system is yet unknown; it is assumed to
be a maximum of 10 years; but, certain system components may have a
shorter life.

For HCl CEMS,

The industry believes installation and certification of HCl CEMS as
currently proposed is expected to cost between $225,000-$250,000
(including FTIR, oxygen monitor, data handling system, heated sampling,
calibration gases, and other ancillary equipment) in system capital
expenses and installation.

There are no current monitors that can measure at levels required by
EPA, and PS-15 is impossible to meet (requires spectroscopist to review
the FTIR data frequently and includes numerous requirements no CEMS in
the world could meet).

Due to special sampling requirements, an FTIR system as prescribed by
EPA could not be part of another CEMS; it would need to have separate
dedicated sampling equipment (special super hot sampling lines) and
separate data acquisition system (DAS).

Estimated capital costs of about $280,000 just to get started on a
system are expected.

Another $30,000 for initial certification of the HCl CEMS is
anticipated.

The total costs for on-going QA are unknown as facilities cannot install
and certify HCl CEMS using PS-5.

Estimated cost includes one full-time person, plus $30,000 for annual
testing, plus $20,000 for an annual service agreement.

For THC CEMS, the Summary of Environmental and Cost Impact document
lists $137,800-$138,900 for installed CEMS costs, and $41,672 for
ongoing costs. However, these are for CO monitors as this document was
prepared some time ago and EPA figured that industry would go with CO
monitors versus THC monitors because they were less costly. An FID
analyzer with dual range with auto switching to get to the low levels
and still measure spikes would be estimated at $25,000 as compared to CO
analyzer $10,000.

For BLDS:

The commenter (2845) does not understand the basis for EPA’s number
for CEMS and BLDS monitoring costs. An estimate for the cost of a
transmissometer (also used as COMS) that meets ASTM D7392-07 for PMDS or
a good quality light scattering instrument is $35,000. According to our
expert on CEMS, a cost of $93,700 is sufficient for any of the
recommended options on the table: BLDS, PMDS, or COMS, assuming
monitoring only at a single location.

A BLDS is needed downstream of each baghouse (kiln, coal mill, by-pass,
etc) whereas a PMD may be able to monitor co-mingled emissions (e.g.,
kiln and coal mill). We are not clear on the assumptions EPA made.
However, on page 17 of the Summary of Environmental Costs Impacts of
Proposed Revisions to Portland Cement NESHAP, EPA assumes 1 sensor per
compartment and 5 compartments for kiln baghouse, and five more of the
same sensors for the clinker cooler baghouse, for a total of 10 sensors.
Thus, the EPA assumed capital cost is approximately $94,000 for 10
monitors. However, the assumption of only 5 compartments for each kiln
baghouse is understated by a factor of at least two times. Thus, EPA’s
estimated capital cost for BLDS on the basis of 1 sensor per compartment
is at least 50 percent low.

Response: The cost model is based on vendor supplied data and has been
placed in the docket for this rulemaking.

RIA and ISIS projections

Comment: One commenter (2845) stated that EPA’s RIA wrongly credited
all projected SO2 emissions reductions in 2013 to the NESHAP by assuming
all kilns operating in 2005 will be in operation in 2013 and will be in
compliance. The RIA also assumes 20 new kilns in operation by 2013. The
ISIS model projects a lower reduction by taking into account natural
plant closures and modernizations. The commenter stated that ISIS offers
significant improvements over EPA’s traditional cost approach. The
commenter stated that the ISIS results are based on outdated projections
regarding future U.S. cement consumption and capacity projections that
were developed before the severity of the current recessions became
apparent. According to the commenter, when EPA re-runs ISIS using
consumption and capacity projections that accurately reflect the impact
of the recession, EPA will predict a reduction in kiln emissions of SO2
in 2013 and the monetized value of the SO2 reduction attributable to the
proposed NESHAP will decline as will the cost estimated for compliance
with the proposed NESHAP.

One commenter (2845) stated that although ISIS offers the potential to
eventually provide a significant improvement over EPA’s previous
economic modeling for the cement industry, presently, ISIS is subject to
numerous shortcomings in data, assumptions, structure and validation.
The commenter does not believe that the current version of ISIS provides
believable estimates of likely economic impacts from the proposed NESHAP
or from other potential environmental requirements. ISIS is so complex
and its deficiencies so pervasive that, until it is substantially
improved, other methods should be used to assess the likely impacts of
the proposed NESHAP. The commenter provided an initial technical review
of the current version of ISIS that EPA has used to estimate the costs
and economic impacts of the proposed rule and also provided comments and
criticisms regarding the model and suggestions for improving and
eventually develops an acceptable version of ISIS. The commenter
submitted additional details and data as part of their comment. In
contrast to EPA’s previous approach, ISIS:

No longer models the U.S. cement industry unrealistically as a
collection of 20 completely independent regional cement markets, with
each cement producer selling product in only their own home market;

Models cement producer behavior as competitive rather than
oligopolistic, dropping the assumption that producers restrain output in
order to raise prices;

Allows a greater potential role for imports, consistent with historical
experience;

Simulates endogenously the full range of potential responses to
regulation instead of assuming many of them as exogenous inputs to the
model; and

In many respects uses updated and better data.

However, notwithstanding its commendable modeling objectives and the
improvements over previous modeling efforts, the current version of ISIS
that is used for the NESHAP analysis needs substantial improvement
before its outputs can be considered to realistically forecast the
impact of EPA regulatory options. The commenter submitted detailed
discussions of its recommendations for improvement to ISIS (see Appendix
13 of the commenter’s submittal).

Response: The ISIS Cement Model has been enhanced by updating cement
consumption and capacity projections, import modeling and transportation
matrix. EPA employed both a partial-equilibrium economic model and the
enhanced version of the ISIS Cement model to analyze the impact on the
industry and the economy. The final documentation of the enhanced
peer-reviewed ISIS model has been placed in the docket for this
rulemaking.

Comment: One commenter (2845) evaluated the potential economic impacts
of the proposed rule and estimated that as many as 30 existing plants
could be forced to close, with an additional 12 at high risk of closure
which will have significant employment and economic impacts as well as
collateral environmental impacts as well including a substantial
increase in imports from non-U.S. plants that are not subject to
stringent environmental standards. This would undermine the mercury
reduction benefits and increase greenhouse gas emissions from the
transportation of cement (the commenter provided additional details in
Appendix 10 to their comments).

Response: Neither our RIA economic analysis or our ISIS analysis
estimated impacts this large.   Based on our analyses, we believe that
up to 10 plants may have reduced capacity utilization during 2013 as a
result of the impacts of this rule.  (Regulatory Impact Analysis:
Amendments to the NESHAP and NSPS for the Portland Cement Manufacturing
Industry, Final Report, August 2010).

Comment: Several commenters (2844, 2846, 2859, and 2919) stated that the
proposed standards will have adverse economic impacts. The proposed
standards will make it cost and technology prohibitive for some plants
to achieve compliance, leading to forced closure of domestic plants that
will create job losses. The reduction of domestic cement production will
require imports, elevate costs, eliminate jobs, and constrain
infrastructure development.

Greater imports of cement will increase use of fossil fuels used for
transportation, and foreign sources of cement are manufactured under
conditions that are not as environmentally protective as in the United
States.

One commenter (2919) noted that the EPA should evaluate the potential
emissions from the production and transport of replacement cement for
those markets affected by plant closures. It does not appear that EPA
has addressed this issue in the preamble to the proposed rule, so the
commenter recommended that EPA evaluate this before finalizing the rule
to ensure that the final rule results in a net environmental benefit in
the event that it causes closure of cement facilities. If EPA chooses to
establish a subcategory for facilities with extremely high mercury
content ore that might otherwise be forced to close, we recommend that
it require the highest level of control achievable for that subcategory.

Response: In the RIA analysis, EPA modeled price, production, import,
and employment changes in a partial equilibrium model. In the benefit
analysis, EPA estimated disbenefits of increased energy consumption
quantitatively and the disbenefits of increased production in foreign
countries qualitatively.

Comment: One commenter (2846) stated that in the current economic
crisis, it is imperative that U.S. industry maintain sufficient
flexibility to improve operations while simultaneously continuing to
improve its record of emissions reductions. EPA’s estimate of the cost
of this proposed rule – over a quarter of a billion dollars annually
– could likely preclude emissions control technology development and
stifle economic growth, rendering the U.S. cement industry incapable of
competing effectively in the global marketplace. Given the increased
infrastructure development likely to take place as a result of the
stimulus package, Council of Industrial Boiler Owners (CIBO) believes
that EPA’s capital cost estimate for the cement industry’s
compliance with the proposed standards is likely inadequate. In imposing
MACT requirements, it is essential that EPA have realistic cost
estimates for its proposed standards, so that the impact of all proposed
standards can be adequately ascertained by all interested parties.

Response: EPA employed both a partial-equilibrium economic model and the
enhanced version of the ISIS Cement model to analyze the impact on the
industry and the economy. In the ISIS Cement model, EPA used the latest
projections on cement consumption from the Portland Cement Association
(October, 2009). The cement consumption projections take into
consideration both the economic crisis as well as the economic recovery
maintaining sufficient flexibility in the analysis of this rulemaking.
The Economic and Impact Analysis for this rulemaking using both of these
can be found in the rulemaking docket.

SO2 reductions

Comment: One commenter (2845) stated that EPA has overestimated
uncontrolled SO2 emissions by about 25 percent as a national total
because emissions were estimated as the tonnage of SO2 emissions abated
by the regulation. As a result, benefits were also overestimated because
SO2 emission reductions were multiplied by a dollar value of benefits
per ton providing benefits that are a linear multiple of the estimated
emissions reduction. It is not clear how EPA estimated the total
national SO2 emissions in either the RIA or Industrial Sectors
Integrated Solutions (ISIS) and it is believed that all of the estimates
for the 2005 SO2 emissions are inaccurate for the following reasons:

Inaccuracies in the data obtained for the 2002 NEI;

Inaccuracies in collapsing individual plant data into regional averages
or medians by kiln type and then into national averages or medians by
kiln type;

Potential inaccuracies in using medians rather than averages;

The error in multiplying emissions intensity (pounds SO2 per ton of
clinker) by clinker capacity in contrast to actual clinker production;

Errors in updating 2002 emission information for individual kilns to
2005 by inflating each kiln’s emissions by the national average
production increase from 2002 to 2005 instead of by each kiln’s actual
production increase over this period;

The potential error in including SO2 emissions from hazardous
waste-burning kilns in the inventory of 2005 baseline emissions that
might be affected by the proposed NESHAP. It is not clear whether EPA
made this error or not;

The commenter has access to a more up-to-date and accurate database
which when compared with EPA’s estimated results, the commenter’s
estimated results were 20 percent lower; therefore, because EPA
overestimated the baseline SO2 emissions by cement kilns in 2005 by
about 25 percent, this led EPA to overestimate the projected SO2-related
monetized benefits by a similar 25 percent. The commenter can provide
more up-to-date data to EPA.

Response:  We did collect additional information to supplement what was
available in the NEI, and we conducted quality control and quality
assurance audits on these data.  EPA believes this is a reasonable
estimate of SO2 reductions.    SO2 emissions from cement kilns are the
product of sulfur in the fuel as well as sulfur in the feed materials.
SO2 emission intensities (lb/ton clinker) were calculated for each kiln
type in each cement market using the SO2 emission data in the National
Emission Inventory (NEI). SO2 emission intensities by kiln type in each
cement market were used to calculate national SO2 emissions in the
traditional engineering analysis as well as in the ISIS model. The
detailed methodology used calculate SO2 emission intensities is
documented in memorandum from Staudt, Andover Technology Partners, to
Srivastava, Torres, Barnett, US EPA, “RE: NOx, SO2 and CO2 emissions
from Cement Kilns (Emissions Memo),” September 23 ,2008.

Comment: One commenter (2845) stated that EPA assumed or estimated an
unrealistically high 95 percent SO2 removal efficiency for all limestone
wet scrubbers (LWS) without regard to the reason for the scrubber (i.e.,
HCl control vs. protecting an RTO) and without regard to the inlet
concentration of SO2. According to the commenter, scrubber manufacturers
indicate that 15 ppm is the lowest SO2 outlet concentration consistently
achievable by wet scrubbers designed for SO2 capture at cement kilns.
The commenter estimated a lower removal efficiency assuming the lowest
achievable outlet concentration of 15ppm.

Commenter 2845 provided an MS Excel workbook showing the calculations as
part of their comment. The commenter projected that the proposed NESHAP
would result in 82 percent of all kilns needing to install scrubbers.
Since it is not known which specific kilns will need scrubbers, the
projected control efficiencies would need to be reduced by in order to
estimate the percentage reduction in SO2 that will likely be achieved in
practice, in contrast to the potential percentage reduction that would
occur if all kilns installed scrubbers.

The commenter stated that it is not clear that the wet scrubbers
installed at cement kilns to meet the proposed NESHAP
requirements–either to control HCl or to protect an RTO installed to
control THC–will achieve the performance that is expected of scrubbers
intended to address SO2. The industry has no experience with wet
scrubbers intended specifically to control HCl to very low levels and
very little experience with scrubbers intended to protect an RTO.
Scrubbers designed specifically for HCl control would scrub using Sodium
Hydroxide (NaOH) and may not be suitable for scrubbers aimed at removing
low concentrations of HCl from flue gas that has a high SO2
concentration. SO2 scrubbers in cement industry generally use limestone
as a scrubbing medium (lower-cost than NaOH, results in recoverable
gypsum and little in the way of solid waste disposal cost). It is not
known how a scrubber would best be designed for removal of low
concentrations of HCl in the presence of high SO2 concentrations, or
whether the SO2 removal performance of such an HCl-optimized scrubber
would differ significantly from the typical performance of SO2-optimized
scrubbers.

Response: EPA has updated the SO2 removal efficiency of limestone wet
scrubbers (LWS) to 90%. The NSPS adopted concurrently contains a 90%
removal efficiency alternative standard for SO2 based on use of a
limestone wet scrubber, and this alternative garnered significant
industry support in the public comments. Consequently, EPA considers a
90% removal efficiency to be a reasonable estimate in assessing
reductions of SO2 in the NESHAP as well. We also disagree with the
statement that wet scrubber optimized to control SO2 will not control
HCl to the low levels required by the rule. Because HCl is more reactive
than SO2, we would expect that a scrubber optimized for 90 percent SO2
control would achieve even a higher level of control for HCl. In fact,
data collected from municipal solid waste incinerators confirms that
spray dryers (a similar SO2 control technology) remove HCl at levels
higher then those for SO2, and achieves level of 90 percent more even
when SO2 removal levels are in the 30 percent range.

Comment: One commenter (2845) stated that using scrubbers to control
acid gas emissions from kilns with already low concentration of SO2 are
not cost-effective for the following reasons:

A majority of the monetized benefits that EPA estimates for the entire
proposed regulation derive from co-control of SO2 by kilns that are
projected to install scrubbers to meet the proposed HCl standard.

The SO2 co-benefits from controlling HCl cannot provide a valid reason
for HCl control requirements unless controlling SO2 itself is shown to
be cost-effective.

Emission control using LWS is not cost-effective for the cement kilns
that already have low concentrations of SO2 because, the commenter
estimated, it would cost more than $36,000 per ton of SO2, which is far
above a reasonable figure of cost-effectiveness for SO2 control. The
commenter provided cost and emissions reduction figures from a BACT
analysis for a single kiln as support.

Response: In the analysis of this rulemaking SO2 emission reductions are
co-benefits of HCl reductions. HCl is a hazardous air pollutant
regulated under section 112 of CAA. As noted in the preamble of the
final rule we are required to set limits for HAP based on maximum
achievable control technology. That is the reason for apply HCl
controls. We do note that SO2 co-benefits are achieved, and are very
significant. It is not necessary that we justify the cost of these SO2
co-benefits (and indeed, since they result from floor standard, EPA is
precluded from considering costs).

For these rules the SO2 reductions represent a large fraction of the
total benefits from reducing PM2.5 , but it is not possible to isolate
the portion if the total benefits attributable to the emission
reductions of SO2 resulting from the application of HCl controls.

Comment: One commenter (2844) stated that there are challenges and
uncertainties in meeting the new limits including the following:

Facilities face extensive control investments because the limits are low
and the controls methods are largely undemonstrated in kiln
applications.

Activated carbon injection (ACI) and scrubber performance is dependent
on having oxidized mercury to treat. The commenter does not know the
distribution of their plants’ elemental and oxidized mercury
emissions.

The proposed standards are cost-ineffective in dollars per ton of
reduced emissions and the risk that even those significant, costly
investments will not assure compliance.

Response: EPA acknowledges that there are challenges and uncertainties
in attaining compliance with new limits under any MACT standard. See the
preamble and cost and environmental impacts documents for discussion of
control costs and estimates of cost effectiveness.

Benefits Analysis

Comment: One commenter (2845) stated that EPA does not estimate the
benefits from control of the HAP whose emissions would be reduced by the
proposed NESHAP. Instead, EPA estimates the monetized benefits
associated with co-control of the criteria pollutants, PM2.5 and SO2 (a
PM2.5 precursor). The commenter stated that EPA performed no dispersion
modeling, exposure assessment or risk analysis for cement plant
emissions. Instead, EPA relied on the benefit per ton estimates
developed in previous RIA. The benefits per ton figure that EPA accesses
and uses for SO2 for the NESHAP benefits analysis reflect work done in
previous RIA (see EPA’s Regulatory Impact Analyses (RIA) for the PM2.5
National Ambient Air Quality Standards (NAAQS)) to quantify the
relationships between SO2 emissions, sulfates, and eventual PM2.5
concentrations attributable to SO2.

One commenter (2845) stated that EPA should not use PM2.5 reductions
that are not required by the rule to justify the cost of the rule for
the following reasons:

Even though the proposed rule was developed to regulate HAP emissions,
EPA estimates that most of the benefits, specifically the monetized
benefits, will come from reducing PM2.5.

Actions taken to reduce HAP emissions will not reduce emissions of PM2.5
and PM2.5 precursors to the extent that EPA has projected. It is
improper for EPA to take credit for PM2.5 benefits that may not be
achieved and that have not been realistically analyzed. EPA should
quantify the benefits of HAP reductions to compare to the costs of the
rule.

EPA estimated that the annualized domestic social cost of this
regulation is $694million and concedes that it does not have sufficient
information to estimate benefits from reductions in emissions of
mercury, HCl, or coarse PM (total hydrocarbons are not mentioned at
all). Nor does EPA discuss the qualitative measures of these benefits,
which must be considered essential to consider per Executive Order
12866. It is not possible to justify the cost of the potential
reductions in the four HAPs without discussion of the benefit of the
proposed reductions.

EPA’s discussion of the secondary benefits does not remedy this defect
in the cost-benefit analysis. Such regulatory intent is contrary to the
CAA State Implementation process. States may mandate PM2.5 controls and
allocate PM2.5 emissions based on unique local considerations or
legislative prerogatives, so long as the national standards are met.
States have virtually absolute power in allocating emission limitations
so long as the national standards are met and so long as the national
standards are met, the implementing state may select whatever mix of
control devices it desires. By setting MACT standards for the reduction
of PM2.5, EPA is usurping the role of the States under the CAA’s NAAQS
program.

Response: As explained in the discussion of EPA’s decision to adopt a
MACT standard for HCl, Congress was aware that there would be
co-benefits from controls on air toxics in the form of co-control of
criteria pollutants, and Congress viewed these co-benefits as a positive
part of the air toxics control effort. It would be ironic indeed if EPA
were precluded from considering these very real benefits in those
instances where it is making discretionary choices under section 112
(d), notably in determining in whether to set a technology-based or
risk-based standard for HAPs with a threshold. Nor does EPA view
consideration of these co-benefits as somehow undermining the SIP
process. Indeed, States are customarily eager for federal controls of
criteria pollutants since otherwise States must adopt localized controls
to attain air quality standards. See e.g., 75 FR at 35570-71 (June 22 ,
2010) (noting importance of forthcoming MACT rules in helping areas
attain primary SO2 NAAQS). In addition:

Data, resource, and methodological limitations prevented EPA from
estimating the monetized benefits from reducing HAP emissions. For the
final rule, EPA provided qualitative descriptions of the health effects
associated with the top HAP emissions from cement kilns. In addition,
EPA provided maps of the modeled reduction in mercury deposition from
cement kilns. Despite our inability to provide monetized benefits of HAP
emission reductions, the total monetized benefits exceed the estimated
costs of the rule by a substantial margin, even when taking uncertainty
into account.

 The goal of an RIA is to provide a comprehensive estimate of the
anticipated costs and benefits associated with a regulatory action.
Co-benefits that occur as a result of a regulatory action are
appropriate to include in the RIA, and it is appropriate to compare the
total monetized benefits with the costs. In many instances, it is not
possible to quantify and monetize all of the benefits associated with a
regulatory action. An RIA is not prepared to justify the costs of an
action, but only to estimate what the likely impacts would be.

The PM2.5 emission reductions that would occur as co-benefits of this
rule do not affect the States’ roles and responsibilities under the
NAAQS program. These emission reductions would occur regardless of an
area’s attainment status under the NAAQS, but these emission
reductions might help those areas that are in non-attainment to reach
attainment. This is a positive feature of the rule, not a negative.

Comment: One commenter (2890) stated that EPA must consistently evaluate
positive and negative impacts of a rule. The commenter’s specific
points were:

EPA cannot monetize the benefits of PM2.5 (or any other pollutant)
reductions to justify action at the floor. As EPA has repeatedly
claimed, the floor level of control shall not consider costs. If you
cannot consider costs to industry in assessing whether a floor is
reasonable, you also cannot use benefits (monetized or otherwise) from
other pollutants in establishing the floor. The floor must stand on its
own and follow the requirements of the Clean Air Act.

EPA cannot monetize the benefits of PM2.5 and ignore the monetized
detriments that would result from the controls. The EPA monetizes the
benefits of PM2.5 control but does not monetize the detrimental impacts
of the energy and other secondary emissions that are included in the
secondary impacts section. This is arbitrary and creates an unfair
depiction of the true impacts of this rule.

Response: The costs and the benefits presented in the RIA do not
influence the MACT floor determination. Consideration of cost (positive
or negative) is absolutely prohibited at the MACT floor, and EPA
necessarily did not consider cost or benefit information in developing
the floors. The floors reflect the average performance of the best 12 %
of existing sources, and the performance of the single best controlled
similar source (for which EPA has emission data), as required by law.
EPA did consider cost information, as well as non-air quality impacts
and energy considerations, in determining not to adopt standard more
stringent than the floor. The RIA describes impacts to energy in the RIA
in section 3.5 and the energy disbenefits in section 6.4.

Comment: One commenter (2845) stated that methodological limitations
should not prevent EPA from estimating the monetized benefits of HAP
emission reductions from the proposed rule. Techniques exist for
conducting multipathway risk assessments for cement kilns for HAP
emissions that EPA and industry have applied many times. For example,
EPA’s worst case screening analysis concludes that an HCl emissions
limit of 23 ppmv would result in no health risk to surrounding
populations from current cement kiln emissions. In addition to risk
modeling for HAP, well-accepted methods for estimating the monetary
value of changes in HAP risks also exist and have been applied.
Executive Order (EO) 12866 requires that EPA must conduct full analysis
of benefits and costs (monetized to the extent possible) for any
economically significant regulations. EPA must analyze the benefits from
HAP emissions reductions as well as criteria pollutant emission
reductions. According to the commenter, analysis of the benefits of the
proposed NESHAP will likely show small to near-zero benefits from the
reductions in HAP emissions. It is believed that hazardous waste-burning
cement kilns will provide a worst case representation for cement kilns
and HAP risks associated with the industry will generally be less than
or equal to those from other hazardous waste-burning kilns.

Response: Data, resource, and methodological limitations prevented EPA
from estimating the monetized benefits from reducing HAPs emissions. For
the final rule, EPA provided qualitative descriptions of the health
effects associated with the top HAP emissions from cement kilns. In
addition, EPA provided maps of the modeled reduction in mercury
deposition from cement kilns. Despite our inability to provide monetized
benefits of HAP emission reductions, the total monetized benefits exceed
the estimated costs of the rule by a substantial margin, even when
taking uncertainty into account.

Comment: One commenter (2845) stated that EPA’s benefits analysis
incorrectly assumes that exposure to and risk from fine particle and
precursor emissions from the portland cement plant emissions is similar
on average to exposure and risk from fine particle and precursor
emissions from all other point sources. The commenter stated that cement
kiln emissions are likely to cause less exposure on average and are less
potent. For both SO2 and directly emitted PM2.5, EPA takes value-per-ton
benefits estimates for nationwide aggregates of these pollutants that
were developed in the Ozone NAAQS RIA and applies these values
specifically to the quantities of cement plant emissions that will be
controlled by the NESHAP. This represents an instance of what economists
term benefits transfer; taking a benefit estimate developed in one
context and applying it in another. Commenter 2845 stated that these
situations are not similar and that the benefits transfers are not
appropriate, for reasons having to do with both exposure and potency. In
support of their comment, the commenter provided analyses of exposure
and potency as factors affecting benefits.

Response: For the final RIA, EPA used the CAMx model to better reflect
the geographic distribution of the emission reductions from cement kilns
on ambient PM2.5 concentrations, which provides a superior
representation compared to the national average benefit-per-ton
estimate.

The benefits models assume that all fine particles, regardless of their
chemical composition, are equally potent in causing premature mortality
because there is no clear scientific evidence that would support the
development of different effects estimates by particle type. The
recently released Integrated Science Assessment for Particulate Matter
concluded that “many constituents of PM can be linked with differing
health effects, but the evidence is not yet sufficient to allow
differentiation of those constituents or sources that are more closely
related to specific health outcomes.” In addition, the Health Effects
Subcommittee of the Science Advisory Board recently stated that “ the
evidence at this time does not currently support this sort of
[differential toxicity] assessment” (EPA-SAB-COUNCIL- 10-001).

Comment: One commenter (2845) stated that EPA made two other smaller
changes in adapting previous benefit-per-ton values for application to
the cement NESHAP; however, did not give a detailed explanation of what
the changes were so that the public could assess them.

Response: EPA concurs that the two technical changes were not
sufficiently described in the proposal RIA. However, this language was
removed because benefit-per-ton estimates were not used as the basis of
the benefits estimates for the final RIA.

In addition to the changes described in the Portland Cement NESHAP
proposal RIA, EPA’s Office of Air and Radiation has also recently
revised the value of a statistical life (VSL) used to calculate the
human health benefits of avoided premature mortality. The final RIA
contains a detailed explanation of this revision.

Comment: One commenter (2845) stated that the various comments provided
regarding EPA’s benefits analysis would sum to a significant reduction
in EPA’s calculated values perhaps down to near the level of costs
that industry is estimating.

Response: EPA has reassessed the monetized benefits and costs for the
final rule, including the energy disbenefits. For the final rule, the
monetized benefits still outweigh the costs by a substantial margin,
even when taking uncertainties into consideration.

Small business impacts

Comment: One commenter (2887) stated that the final rule should minimize
impacts on small business. The Regulatory Flexibility Act (RFA), as
amended by the Small Business Regulatory Enforcement Fairness Act
(SBREFA), 5 U.S.C. §601 et seq., imposes procedural requirements on EPA
that must be followed in promulgating a rule. The commenter requested
that the EPA minimize the economic impact of the final Portland Cement
NESHAP on small entities. EPA’s analysis of the economic impact of the
proposed rule on small business cement plants suggested that the highest
single impact based on a cost-to-sales ratio is on a small entity.

The commenter respectfully disagrees that the EPA minimized the impact
on small entities in the proposed rule. Small entities are subject to
the same MACT floor standards as larger businesses. To the extent that
the rule includes any provision that minimizes the impact on small
entities as compared to large businesses, the commenter requests that
the EPA specifically identify those provisions and explain the
difference in economic impact between small businesses and larger
companies. More importantly, the commenter does not agree that the MACT
floor is the least stringent level allowed by law.

Response: To the extent the commenter suggests that EPA should have
altered the floor methodology to accommodate small businesses, the
comment is misplaced because the requirements for MACT floors are
non-discretionary and dictated by statute. EPA is also certifying that
the final rule does not have a significant impact on a substantial
number of small businesses.

We estimate that 3 of the 26 existing Portland cement entities are small
entities and will not incur any impacts under the final amendments for
NSPS subpart F unless an affected facility is constructed, modified, or
reconstructed. Although this final NSPS will not have a significant
economic impact on a substantial number of small entities, EPA
nonetheless has tried to reduce the impact of this rule on small
entities by the selection of an emission level based on highly
cost-effective controls and specifying monitoring requirements that are
the minimum to ensure compliance. In the case where there are
overlapping standards between this NSPS and the Portland Cement NESHAP,
we have exempted sources from the least stringent requirement thereby
eliminated overlapping monitoring, testing and reporting requirements by
requiring that the source comply with only the more stringent of the
standards.

For subpart LLL (NESHAP), EPA performed a screening analysis for impacts
on the three affected small entities by comparing compliance costs to
entity revenues. EPA’s analysis found that the ratio of compliance
cost to company revenue for one small entity (a tribal government) will
have an annualized cost of less than 1 percent of sales. The other two
small businesses will have an annualized cost of between 1 and three
percent of sales. Although this final NESHAP will not impact a
substantial number of small entities, EPA nonetheless has tried to
reduce the impact of this proposed rule on small entities by setting the
final emissions limits at the MACT floor, the least stringent level
allowed by law. In the case where there are overlapping standards
between this NESHAP and the Portland Cement NSPS, we have exempted
sources from the least stringent requirement thereby eliminating the
overlapping monitoring, testing and reporting requirements by requiring
that the source comply with only the more stringent of the standards. In
addition, we applied MACT for HCl emissions to major sources only. The
reduced compliance costs for two of the three small entities by a factor
of 4.

More discussion is provided in the preamble.

Comment: In extrapolating from available data, one commenter (2845)
asked if EPA has applied the correct basis for factors, such as using
the correct percentage of raw mill on versus raw mill off when applying
the emission rate to additional facilities (can affect mercury, HCl, and
SO2)? Have operational considerations across the various kiln types been
taken into account?

Response: When appropriate, EPA did take into consideration the effects
of the process on emission rates. For example, in identifying the top
performing kilns for PM emissions, we recognized that PM emissions were
generally higher during raw mill off conditions compared to raw mill on.
As a result, we calculated a weighted average PM emission level for
kilns with raw mills where we had test data for both raw mill on and off
conditions. When we collected additional HCl data, we specified that for
kilns with raw mill, HCl testing was to be done with the raw mill on and
off. The mercury emissions limit w as based on 30-days of raw material
sampling and analysis for mercury content so that the raw mill status
was not an issue. Also, the THC limit was based on long-term (hundreds
of days) CEM data which would account for the raw mill. In addition, all