

[Federal Register: December 20, 2006 (Volume 71, Number 244)]
[Rules and Regulations]               
[Page 76517-76552]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20de06-28]                         


[[Page 76517]]

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Part IV





Environmental Protection Agency





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40 CFR Part 63



National Emission Standards for Hazardous Air Pollutants From the 
Portland Cement Manufacturing Industry; Final Rule and Proposed Rule


[[Page 76518]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2002-0051; FRL-8256-4]
RIN 2060-AJ78

 
National Emission Standards for Hazardous Air Pollutants From the 
Portland Cement Manufacturing Industry

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: On June 14, 1999, under the authority of section 112 of the 
Clean Air Act (CAA), EPA promulgated national emission standards for 
hazardous air pollutants (NESHAP) for new and existing sources in the 
Portland cement manufacturing industry. On December 15, 2000, the 
United States Court of Appeals for the District of Columbia Circuit 
(D.C. Circuit) remanded parts of the NESHAP for the Portland cement 
manufacturing industry to EPA to consider, among other things, setting 
standards based on the performance of the maximum achievable control 
technology (MACT) floor standards for hydrogen chloride (HCl), mercury, 
and total hydrocarbons (THC), and metal hazardous air pollutants (HAP).
    EPA published a proposed response to the court's remand on December 
2, 2005. We received over 1700 comments on the proposed response. This 
action promulgates EPA's final rule amendments in response to the 
court's remand and the comments received on the proposed amendments.

DATES: This final rule is effective on December 20, 2006.

ADDRESSES: EPA has established a docket for this action under Docket ID 
No. EPA-HQ-OAR-2002-0051. All documents in the docket are listed on the 
http://www.regulations.gov Web site. Although listed in the index, some 

information is not publicly available, e.g., confidential business 
information (CBI) or other information whose disclosure is restricted 
by statute. Certain other material, such as copyrighted material, is 
not placed on the Internet and will be publicly available only in hard 
copy form. Publicly available docket materials are available either 
electronically through http://www.regulations.gov or in hard copy at EPA 

Docket, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW., 
Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 
p.m., Monday through Friday, excluding legal holidays. The telephone 
number for the Public Reading Room is (202) 566-1744, and the telephone 
number for EPA Docket Center is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Mr. Keith Barnett, EPA, Office of Air 
Quality Planning and Standards, Sector Policies and Programs Division, 
Metals and Minerals Group (D243-02), Research Triangle Park, NC 27711; 
telephone number (919) 541-5605; facsimile number (919) 541-3207; e-
mail address barnett.keith@epa.gov.

SUPPLEMENTARY INFORMATION:

I. General Information

    A. Does this action apply to me? Entities potentially affected by 
this action are those that manufacture Portland cement. Regulated 
categories and entities include:

                   Table 1.--Regulated Entities Table
------------------------------------------------------------------------
                                                   Examples of regulated
           Category                 NAICS \1\             entities
------------------------------------------------------------------------
Industry......................  32731............  Owners or operators
                                                    of Portland cement
                                                    manufacturing
                                                    plants.
State.........................  None.............  None.
Tribal associations...........  None.............  None.
Federal agencies..............  None.............  None.
------------------------------------------------------------------------
\1\ North American Industry Classification System.

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
action. This table lists the types of entities that may potentially be 
regulated by this action. To determine whether your facility is 
regulated by this action, you should carefully examine the 
applicability criteria in 40 CFR 63.1340 of the rule. If you have 
questions regarding the applicability of this action to a particular 
entity, consult the person listed in the preceding FOR FURTHER 
INFORMATION CONTACT section.
    B. Judicial Review. The NESHAP for the Portland Cement 
Manufacturing Industry were proposed in December 2, 2005 (70 FR 72330). 
This action announces EPA's final decisions on the NESHAP. Under 
section 307(b)(1) of the CAA, judicial review of the final NESHAP is 
available only by filing a petition for review in the U.S. Court of 
Appeals for the D.C. Circuit by February 20, 2007. Under section 
307(d)(7)(B) of the CAA, only an objection to a rule or procedure 
raised with reasonable specificity during the period for public comment 
can be raised during judicial review. Moreover, under section 307(b)(2) 
of the CAA, the requirements established by the final NESHAP may not be 
challenged separately in any civil or criminal proceeding brought to 
enforce these requirements.
    C. How is this Document Organized? The information presented in 
this preamble is organized as follows:

I. General Information
II. Background
III. Summary of the National Lime Association v. EPA Litigation
IV. EPA's Final Action in Response to the Remand
    A. Determination of MACT for Mercury Emissions
    B. Determination of MACT for HCl Emissions
    C. Determination of MACT for THC Emissions
    D. Evaluation of a Beyond-the-Floor Control Option for Non-
Volatile HAP Metal Emissions
V. Other Rule Changes
VI. Responses to Major Comments
VII. Summary of Environmental, Energy, and Economic Impacts
    A. What facilities are affected by the final amendments?
    B. What are the air quality impacts?
    C. What are the water quality impacts?
    D. What are the solid waste impacts?
    E. What are the energy impacts?
    F. What are the cost impacts?
    G. What are the economic impacts?
VIII. Statutory and Executive Order Reviews
    A. Executive Order 12866, Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Analysis
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132, Federalism
    F. Executive Order 13175, Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045, Protection of Children From 
Environmental Health Risks and Safety Risks
    H. Executive Order 13211, Actions That Significantly Affect 
Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Congressional Review Act

[[Page 76519]]

II. Background

    Section 112(d) of the CAA requires EPA to set emissions standards 
for major stationary sources based on performance of the MACT. The MACT 
standards for existing sources must be at least as stringent as the 
average emissions limitation achieved by the best performing 12 percent 
of existing sources in the category or subcategory or the best 
performing five sources for source categories with less than 30 sources 
(CAA section 112(d)(3)(A) and (B)). This level is called the MACT 
floor. For new sources, MACT standards must be at least as stringent as 
the control level achieved in practice by the best controlled similar 
source (CAA section 112(d)(3)). EPA also must consider more stringent 
``beyond-the-floor'' control options. When considering beyond-the-floor 
options, EPA must consider not only the maximum degree of reduction in 
emissions of HAP, but must take into account costs, energy, and non-air 
quality health environmental impacts when doing so.
    On June 14, 1999 (64 FR 31898), in accordance with these 
provisions, EPA published the final rule entitled ``National Emission 
Standards for Hazardous Air Pollutants From the Portland Cement 
Manufacturing Industry'' (40 CFR part 63, subpart LLL).\1\
    The legacy public docket for the final rule is Docket No. A-92-53. 
The final rule provides protection to the public by requiring Portland 
cement manufacturing plants to meet emission standards reflecting the 
performance of the MACT. Specifically, the 1999 final rule established 
MACT-based emission limitations for particulate matter (as a surrogate 
for non-volatile HAP metals), dioxins/furans, and for greenfield \2\ 
new sources, THC (as a surrogate for organic HAP). We considered, but 
did not establish limits for, THC for existing sources and HCl or 
mercury for new or existing sources. In response to the mandate of the 
D.C. Circuit arising from litigation summarized below in this preamble, 
on December 2, 2005, we proposed amendments addressing standards for 
these pollutants. We received over 1700 comments on the proposed 
amendments. Most of these comments were from the general public and 
addressed the lack of a mercury emission limitation in the proposed 
amendments. This final action reflects our consideration of these 
comments. We have previously amended the Portland Cement NESHAP. 
Consistent with the terms of a settlement agreement between the 
American Portland Cement Alliance and EPA, EPA adopted final amendments 
and certain interpretative clarifications to the rule on April 5, 2002 
(76 FR 16614), July 5, 2002 (67 FR 44766), and December 6, 2002 (67 FR 
72580). These amendments generally relate to the rule's applicability, 
and to the performance testing, and monitoring provisions of the rule. 
In this action, we are also amending the rule to re-insert two 
paragraphs relating to the applicability of the Portland cement new 
source performance standards that were deleted in error in a previous 
amendment.
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    \1\ Cement kilns which burn hazardous waste are in a separate 
class of source, since their emissions differ from Portland cement 
kilns as a result of the hazardous waste inputs. Rules for hazardous 
waste-burning cement kilns are found at subpart EEE of part 63.
    \2\ A new greenfield kiln is a kiln constructed after March 24, 
1998 at a site where there are no existing kilns.
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    It should be noted that the rule text presented in this notice 
includes parts of the rule that are not being amended. This is done 
because, in some cases, adding additional rule text reduces the 
possibility of errors in updating the Code of Federal Regulations.

III. Summary of the National Lime Association v. EPA Litigation

    Following promulgation of the NESHAP for Portland cement 
manufacturing, the National Lime Association and the Sierra Club filed 
petitions for review of the standards in the D.C. Circuit. The American 
Portland Cement Alliance, although not a party to the litigation, filed 
a brief with the court as amicus curiae. The court denied essentially 
all of the petition of the National Lime Association, but granted part 
of the Sierra Club petition.
    In National Lime Association v. EPA, 233 F. 3d 625 (D.C. Cir. 
2000), the court upheld EPA's determination of MACT floors for 
particulate matter (PM) (as a surrogate for non-volatile HAP metals) 
and for dioxin/furan. However, the court rejected EPA's determination 
that it need not determine MACT floors for the remaining HAP emitted by 
these sources, namely, mercury, other organic HAP (for which THC are a 
surrogate), and HCl (233 F. 3d at 633). The court specifically rejected 
the argument that EPA was excused from establishing floor levels 
because no ``technology-based pollution control devices'' exist to 
control the HAP in question (Id. at 634). The court noted that EPA is 
also specifically obligated to consider other pollution-reducing 
measures including process changes, substitutions of materials inputs, 
or other modifications (Id.). The court remanded the rule to EPA to set 
MACT floor emission standards for HCl, mercury, and THC. (Id. At 641.)
    The Sierra Club also challenged EPA's decision not to set beyond-
the-floor emission limits for mercury, THC, and non-volatile HAP metals 
(for which PM is a surrogate). The court only addressed the absence of 
beyond-the-floor emission limits for non-volatile HAP metals since EPA 
was already being required to reconsider MACT floor emission standards 
for mercury, THC, and HCl, and thus, by necessity, also must consider 
whether to adopt beyond-the-floor standards for these HAP. The Sierra 
Club argued, and the court agreed, that in considering beyond-the-floor 
standards for non-volatile HAP metals, EPA considered cost and energy 
requirements but did not consider non-air quality health and 
environmental impacts as required by the CAA (Id. at 634-35). The court 
also found EPA's analysis of beyond-the-floor standards deficient in 
its assertion that there were no data to support fuel switching 
(switching to natural gas) as a viable option of reducing emissions of 
non-volatile HAP metals (Id. at 635).

IV. EPA's Final Action in Response to the Remand

A. Determination of MACT for Mercury Emissions

1. Floor Determinations
    In developing the proposed amendments we systematically evaluated 
all possible means of developing a quantified floor standard for 
mercury emissions from these sources, including both back end 
technology-based pollution control devices and front end feed and fuel 
control. See National Lime, 233 F. 3d at 634 (finding that EPA had 
erred in examining only technological (i.e., back-end) controls in 
considering a level for a mercury floor). We also were unable to devise 
any type of work practice standard that would result in mercury 
emissions reductions (70 FR 72332--72335, December 2, 2005).\3\
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    \3\ Indeed, most of the options EPA considered are really 
beyond-the-floor alternatives, because they reflect practices that 
differ from those now in use by any existing source (including the 
lowest emitters). (Coal switching, switching to natural gas, and raw 
material switching are examples.) In EPA's view, a purported floor 
standard which forces every source in a category to change its 
practices is a beyond-the-floor standard. Such a standard may not be 
adopted unless EPA takes into account costs, energy, and non-air 
health and environmental impacts. 70 FR 72335.
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    In response to comments on the proposed standards, we have 
performed additional evaluations of potential floors for mercury 
emissions (and also performed additional evaluations of

[[Page 76520]]

beyond-the-floor options for mercury control). We obtained additional 
mercury emissions test data during and after the two comment periods on 
the proposed amendments and once again evaluated setting a floor based 
on the median of the 12 percent of the kilns demonstrating the lowest 
mercury emissions in stack tests. We discuss each of these 
possibilities in turn below.
    a. Control of Mercury in Primary \4\ Raw Materials and Fossil 
Fuels. i. Mercury Emission Levels Reflecting Raw Material and Fossil 
Fuel Contributions are Inherently Site-Specific.
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    \4\ We discuss in section IV.A.1.c below floor determinations 
for cement kilns using secondary materials (utility fly ash) as raw 
materials, in place of primary materials.
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    As stated at proposal, mercury emissions come from the predominant 
input to a cement kiln by volume: The limestone which is the chief raw 
material for the kiln.\5\ Small amounts of mercury also are found in 
other raw material inputs to the process.\6\ Fossil fuel, almost always 
coal, is the other source of mercury emissions. Mercury levels in 
limestone vary enormously, both within a single quarry and between 
quarries, the result being that a single source may be unable to 
replicate its own performance in different tests, and could not 
duplicate a second source's performance since a kiln lacks access to 
any other kiln's limestone. Mercury levels in coal likewise vary 
significantly, although mercury emissions due to coal are normally 
swamped by the emissions attributable to limestone (70 FR 72333-34).
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    \5\ Limestone makes up approximately 75 percent of the mass 
input to the kiln. Typically the way a cement plant is sited is that 
a limestone quarry suitable for cement production and that is 
expected to provide many years of limestone is identified and the 
plant is built next to the quarry. There are cases where a cement 
plant may purchase small amounts of limestone to blend with the 
limestone from its quarry. However, this close proximity of the 
quarry and cement plant is an inherent part of the cement 
manufacturing process and, therefore, a cement plant does not have 
the flexibility to obtain the bulk of its limestone from any other 
source. See 70 FR 72333.
    \6\ Post-proposal review of available data on other mercury raw 
materials indicates that other feed materials also contribute some 
mercury, though, in most cases, less than limestone. Other raw 
materials include (but are not limited to): shale or clay to provide 
alumina; iron ore to provide iron; and sand to provide silica. These 
raw materials are used in lesser amounts than limestone, and a 
cement plant may have some flexibility in the sources of other raw 
materials. As noted in the preamble to the proposed amendments, 
there are cases where a facility made changes to their raw materials 
(other then limestone) to reduce mercury emissions. However, this 
type of control is site specific based on the available materials 
and the chemical composition of the limestone. The site specific 
factors preclude using this as a basis for a national rule (70 FR 
72334).
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    In an attempt to quantify the potential variability, we looked to 
see if there were facilities with multiple stack tests for mercury. We 
do have multiple test results for one of the lowest mercury emitters in 
the data base. During the first test with the raw mill on \7\ the 
facility was one of the lower emitting facilities in the source 
category demonstrating emissions of 7.8 micrograms per dry standard 
cubic meter ([mu]g/dscm) (all test values are corrected to seven 
percent oxygen). During a second test 8 years later (reflecting raw 
materials from the same quarry) mercury emissions with the raw mill on 
were 60 [mu]g/dscm, a variability factor of roughly 8 times. We could 
identify no facility operational changes between the times of the two 
tests that would account for this large difference in mercury 
emissions.
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    \7\ See section c. below discussing operation of the in-line raw 
mill and its implication for mercury control.
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    We also obtained data from a facility that was retested for mercury 
in July 2005, within 3 months of an initial test. With the raw mill on, 
mercury emissions averaged 0.00138 pounds per hour in the April test 
and 0.00901 pounds per hour in the July test, a variability factor of 
7. With the raw mill off, emissions averaged 0.00823 pounds per hour in 
the April test and 0.0189 pounds per hour in the July test. We also 
noted that during the April test mercury emissions with the raw mill 
off were below mercury emissions with the raw mill on in the July test. 
Because it is known that when the raw mill is on the raw meal adsorbs 
mercury, thereby reducing measured mercury emissions in the short term, 
we can only assume that the uncontrolled variation in the mercury 
levels in the raw materials--all of which come from the same quarry--
was so great between the two tests that it negated the effect of the 
operating condition of the raw mill.
    We also assessed potential variability by examining daily 
variations in cement kilns' raw materials and fuel mercury contents. We 
obtained data from an operating facility that analyzed samples of raw 
material and fuel each day over a 30 day period. We calculated average 
daily emissions assuming all the mercury in the raw materials and fuel 
was emitted. The average daily emissions would vary from a low of 0.09 
lb to a maximum of 16.44 lb, or a factor of 183 (See Summary of Mercury 
Test data in Docket 2002-0051).
    These are enormous swings in variability.\8\ Moreover, it is 
virtually certain that the variability reflected in these results fails 
to cabin the total raw material and emissions variability experienced 
by the plants in the source category, since we have only a handful of 
results. These data confirm our tentative conclusion at proposal that 
constantly changing concentrations of mercury in kiln inputs leave no 
reliable way to quantify that variability. 70 FR 72333.
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    \8\ Variability of emissions based on the operation of air 
pollution controls are typically lower that those shown above 
because air pollution controls are typically designed to meet 
certain percent reduction or outlet emissions levels and to account 
for variations in inlet conditions.
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    In the proposed amendments we also evaluated requiring facilities 
to switch from coal to natural gas as a method to reduce mercury 
emissions, or requiring use of so-called clean coal (70 FR 72333-34). 
We tentatively concluded that this was not feasible on a national basis 
due to insufficient supply and lack of infrastructure, and reiterate 
that conclusion here. One commenter noted that petroleum coke was 
another fuel that is lower in mercury and is currently used as a cement 
kiln fuel. However, a mercury standard based on requiring fuel 
switching to petroleum coke suffers from the same defects as requiring 
facilities to switch to natural gas. This fuel may not be available in 
all areas of the country and there may not be sufficient availability 
of the fuel to replace a significant percentage of the coal burned in 
cement kilns. Petroleum coke is a byproduct of petroleum refining, 
therefore the supply is limited by the demand for refined petroleum 
fuels. Petroleum coke has a low volatile matter content which can lead 
to ignition problems if burned without a supplemental fuel. It also 
typically has a higher sulfur content than coal. This can adversely 
affect kiln refractory life and increase internal corrosion of the kiln 
shell. As previously noted, each individual facility has specific 
requirements for raw material additives based on the chemical 
composition of its limestone. The minerals present in the coal ash 
fulfill part of those requirements. Therefore, replacing part or all of 
the coal currently used at a facility with petroleum coke, which has 
almost no ash, may force the facility to incorporate additional raw 
material additives containing mercury to compensate for the loss of the 
coal ash.
    Thus, we adhere to the tentative conclusion reached at proposal: 
front end feed and fuel control of cement kilns is inherently site 
specific, and basing limits on kiln performance in individual 
performance tests which reflect only those inputs will result in 
limitations that kilns can neither duplicate (another kiln's 
performance) nor replicate (its own).

[[Page 76521]]

    ii. Implications of Permit Limits for Mercury. There are currently 
19 cement kilns (out of 70 cement kilns for which we reviewed permit 
requirements) that have permit limits for mercury. At first blush, it 
might be argued that these permit limits demonstrate that variability 
of mercury emissions can be controlled, since sources must comply with 
the limitations. It might further be argued that these permit limits 
are ``emission limitations achieved,'' the statutory basis for 
establishing floors for existing sources under section 112(d)(3). 
Likewise, for new sources, the lowest permit limit is arguably a 
measure of performance of the ``best controlled similar source'' (the 
permit itself being the means of control). We have determined, however, 
that for most facilities, the permit limit was established based on an 
estimate provided by the facility of the annual amounts of mercury that 
would enter the kiln with the raw materials and fuels. One facility had 
a mercury limit based on its estimated annual emission from an 
emissions test, and one facility had a limit based on a State law, 
although in neither case did the resulting permit cause a cement kiln 
source to alter or otherwise modify its existing practices to meet the 
limit. Thus, we find no cases where a facility actually has had to take 
any steps, either through the imposition of process changes or add-on 
controls, to reduce its mercury emissions as a result of any of these 
permit limits. See ``Summary of Cement Kiln Permit Data for Mercury'' 
in the docket.
    We considered the option of setting an emissions limit, either on a 
pounds per year (lb/yr) or a pound per ton of clinker basis, based on 
the median of the top 12 percent of the 17 kilns with permit 
limitations. However, we repeat that none of the facilities with permit 
limits were required to actually take action to reduce mercury 
emissions. Their limits were all based on site specific factors 
(expected maximum conceivable levels of mercury emissions), and were 
set at a level that did not require the imposition of add-on controls, 
feed or fuel substitution, or any other constraint. Any limit we set 
based on these permits would require that at least some facilities 
apply beyond-the-floor control technology to meet the limit since feed 
and fuel control via substitution is not possible. Such a standard 
would impermissibly apply beyond-the-floor emission control without 
consideration of costs and other non-air health and environmental 
impacts.
    We also considered a limit where each facility would set their own 
site specific limit based on the same procedures the facilities with 
permits used: determining in the course of the permitting process what 
its maximum conceivable mercury emissions are likely to be based on the 
facility's raw material and fuel inputs, and tacking on an additional 
variability factor. However, this would require that we set a separate 
limit for each facility, with each facility being its own subcategory 
(i.e. a different type of facility) based on its site specific raw 
materials and fuels. See 70 FR 72334, alluding to this possibility. EPA 
has great discretion in deciding whether or not to subcategorize within 
a source category. We do not believe a decision to individually 
subcategorize is warranted considering the fact that the result will be 
no discernable environmental benefit because conduct will be unaltered. 
Chemical Mfr's Ass'n v. EPA, 217 F. 3d 861, 866-67 (D.C. Cir. 2000) 
(arbitrary and capricious for EPA to impose costly regulatory 
obligations without some showing that the requirement furthers the 
CAA's environmental goals).
    Therefore, we have determined that even though these permit limits 
exist, they have not resulted in a quantifiable reduction of mercury 
emissions. Any option to develop a MACT floor for mercury with these 
limits would either result in an unnecessarily complex rule with no 
environmental benefit, or a rule which improperly imposes a de facto 
beyond-the-floor standard without the required consideration of costs, 
energy and non-air quality impacts.
    iii. Why not Average the Performance Test Data? Some commenters 
stated that EPA must simply average the results of the 12 per cent 
lowest mercury performance test data to establish the floor for 
existing sources, and establish the new source performance floor at the 
level of the lowest test result. We rejected this approach at proposal, 
and do so here, because it fails to account for the variability of 
mercury levels in raw materials and fuels and hence variability in 
performance. See 70 FR 72335; see also 70 FR 59436 (Oct. 12, 2006). We 
must, of course, account for sources' variability in establishing a 
MACT floor. Mossville Environmental Action Now v. EPA, 370 F. 3d 1232, 
1241-42 (D.C. Cir. 2004). The only way all kilns, including the kilns 
with the lowest emission levels in individual tests, could meet this 
type of standard continuously, as required, would be to install backend 
technology-based control equipment. However, this would be a de facto 
beyond-the-floor standard, adopted impermissibly because of failure to 
assess cost, energy, and non-air quality health and environmental 
impacts. See 70 FR 72335.
    We are aware that in the case of the NESHAP for Industrial, 
Commercial, and Institutional Boilers and Process Heaters (Boiler 
NESHAP), we used short term emissions data and applied a variability 
factor to determine a floor for mercury emissions (69 FR 55236, 
September 13, 2004). We do not believe that approach is applicable to 
the Portland cement source category. First, in the case of the Boiler 
NESHAP the floor was based on performance of a control technology, 
fabric filters, which means that facilities were exercising some 
control over mercury emissions and variability could be realistically 
cabined and quantified, so that an emission limit could be replicable 
and duplicable. Though the majority of cement kilns also use fabric 
filters, the collected particulate in this source category consists of 
product and, to some extent, unprocessed raw materials. As a result 
most of the collected particulate is recycled back to the process, 
largely negating any impact of the particulate control technology on 
mercury emissions.\9\ Second, the variabilities seen as a result of 
fuel inputs in the Boiler NESHAP are much lower than the variabilities 
indicated in the Portland cement industry where the mercury fuel 
variability is a distant second to the enormous variability of mercury 
in the raw materials. We do not believe the data exist to accurately 
quantify this variability.
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    \9\ As explained in the following section of the preamble, 
however, EPA has determined that the floor for both existing and new 
sources involves the removal from the kiln system of collected 
particulate under designated circumstances. In addition, the floor 
for new sources reflects reductions in mercury based on performance 
of a wet scrubber.
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    Another option we considered was using long term data to set a 
floor. However, since, to our knowledge, continuous emission monitors 
for mercury have not been demonstrated on cement kilns, and none 
currently exist on cement kilns, there is no long term stack 
performance data on mercury emissions from cement kilns that we could 
use to set a numerical emissions limit. The only available long term 
data of which we are aware is from several facilities which have a 
requirement to perform monthly analyses of composited daily samples of 
fuels and raw materials to calculate a 12 month mercury emissions 
total. However, all these kilns are located in one state (Florida) with 
unrepresentatively low levels of mercury in limestone (so far as we can 
determine). We do not believe these data would be representative of

[[Page 76522]]

the source category as a whole. More basically, basing a standard on 
one set of kilns' raw material inputs still suffers from the defect 
that no facility has access to another's raw materials.
    b. Floors for Facilities Using Utility Fly Ash as Raw Material. 
Some cement kilns use utility fly ash as an alternative raw material to 
replace shale or clay.\10\ These kilns replace a natural material, 
shale or clay, with a secondary material (i.e. a recycled air pollution 
control residue), fly ash. Approximately 34 cement manufacturing 
facilities are currently using utility boiler fly ash as a feedstock. 
We reviewed the available data and have come to the conclusion that 
cement kilns using fly ash are a different type of kiln, within the 
meaning of section 112 (d) (1) of CAA, and that for cement kilns 
currently using fly ash, the current use would be considered the MACT 
floor. Our reasoning is as follows.
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    \10\ Though these are also raw materials inputs, the mass of 
clay or shale is typically less than 15 percent of the mass input to 
the kiln. Limestone makes up approximately 80 percent of the mass 
input.
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    Use of fly ash can have an effect on mercury emissions since fly 
ash contains mercury in varying amounts. As discussed below, mercury 
emissions may be higher or lower depending on the amounts of mercury 
involved vis-a-vis the raw materials that would otherwise be used (if 
available). But as also explained more fully below, some cement kilns 
using fly ash do not have an alternative raw material source. Given 
that these kilns use a different raw material, not always replaceable, 
and that the material affects mercury emissions, we believe that these 
kilns are a separate kiln type, and hence a separate subcategory, for 
purposes of mercury emissions. For a similar conclusion see 64 FR at 
52871 (Sept. 30, 1999) (cement kilns that choose to burn hazardous 
waste in place of fossil fuels are a separate source category for MACT 
purposes).
    We attempted to determine if, in general, facilities that use fly 
ash have higher emissions of mercury than those that do not. An 
analysis of data for EPA's toxic release inventory and the National 
Emissions Inventory did not show differences significant enough that we 
could draw any definitive conclusions. We considered reviewing the 
available mercury emissions test data to determine if we could discern 
a trend. However, as previously discussed, we do not believe these data 
are representative of long term mercury emissions. We also attempted to 
obtain data on the important issue of the amounts and mercury contents 
of fly ash used relative to other raw materials. These data apparently 
do not exist, with one exception discussed in the next paragraph. We do 
know that the two highest mercury emitting facilities (in individual 
performance tests) do not use fly ash. Without data on the actual 
mercury contributions of all materials, we do not believe we can draw 
any valid general conclusions on the impact of the use of fly ash on 
mercury emissions.
    We do have detailed data from one facility that used fly ash where 
50 percent of the total mercury input to the kiln is in the fly ash. 
However, even for this facility, we cannot accurately quantify the 
impact on mercury emissions of the decision to replace the shale used 
at this facility with fly ash because we have been unable to obtain 
data on the mercury content of the shale the fly ash replaced. We also 
have no mercury analysis data from the time period when the facility 
used shale.
    There are other factors to consider when we evaluate the 
environmental effects--generally quite positive--of substituting fly 
ash for shale or clay. First, fly ash in general has a lower organic 
material content than shale or clay. At the facility just mentioned, 
replacing the shale with fly ash reduced emissions of THC from around 
80 parts per million by volume (ppmv) to 3 ppmv. Because fly ash can 
reduce kiln fuel consumption, it reduces emissions of sulfur dioxide 
(SO2), oxides of nitrogen (NOX), and carbon 
monoxide (CO2). Using fly ash as a kiln feed reduces the 
landfill requirements for disposal of utility fly ash. Use of fly ash 
reduces cement plant power consumption because it is usually fine 
enough that it can be added directly to the kiln rather then being 
ground in a mill. Use of fly ash also reduces fuel consumption because 
compared to the raw materials it typically replaces it is already 
highly calcined; it does not have the same types of large crystals as 
the raw materials it replaces (this improves burnability); some fly 
ashes have lower metal alkali content, thus avoiding hard burning to 
drive off alkali metals and reducing the need to operate the alkali 
bypass; it is drier than quarried materials, thus saving fuel used to 
dry materials. Many domestic cement plants have high pyrites in their 
quarry, especially in the shale or clay. In most cases, this pyrite is 
the main source of SO2 emissions from the kiln. Using fly 
ash can significantly reduce the SO2 emissions that result 
from pyrite in the raw materials. It also reduces the energy required 
for the quarring, milling, and transporting of the shale or clay prior 
to its use as a feedstock, as well as the associated air emissions.
    It should also be noted that there are at least two new facilities 
whose permits specifically require use of fly ash as their alumina 
source, as they have no source for shale or clay, the primary material 
alternatives for alumina. Finally, a facility that currently uses fly 
ash may not be able to return to using the natural (i.e. primary) raw 
materials it replaced. For example, if the replaced raw materials were 
shale, the shale quarry may now be closed and the facility may not have 
access to a suitable shale supply.
    Given the lack of any data to positively state the impact of fly 
ash on mercury emissions for the source category in general, as well as 
the positive environmental effects of using fly ash, there is no basis 
for a floor standard based on substituting other potential raw 
materials (such as shale or clay) for fly ash. At the same time, we do 
not see any means of identifying a floor for existing fly ash users 
based on substituting different fly ash types reflecting different 
mercury content. The recycled fly ash is not fungible. Cement kilns 
must carefully select only fly ash with needed properties within a 
relatively small tolerance. Cement kilns also usually are limited to 
fly ash available from boilers which are reasonably close to the kiln 
(typically within a few hundred miles) or shipping expense becomes 
prohibitive. The fly ash selection process is involved; it has taken 
years for kilns to identify a suitable fly ash source. Accordingly, we 
evaluate fly ash like the other raw material inputs into cement kilns, 
and do not believe that a floor that is based on substitution of either 
raw materials or other fly ash is justified because the input is 
variable and uncontrollable. We discuss in section IV.A.2 below the one 
exception to this conclusion for fly ash where the mercury content has 
been artificially increased by sorbent injection.
    c. Control of Collected Particulate (Cement Kiln Dust). There are 
two operation factors that impact measured mercury emissions at the 
kiln stack. These are the use of in-line raw mills and the recycling of 
cement kiln dust (CKD).
    Many (but not all) kiln systems have in-line raw mills. In these 
systems the kiln exhaust gas is routed through the raw mill to dry the 
raw materials. This process results in mercury contained in the flue 
gas being adsorbed by the raw meal.\11\ This results in an apparent

[[Page 76523]]

reduction if mercury emissions are being measured at the kiln stack. 
However, the captured mercury is reintroduced into the kiln which 
creates a recycle loop of mercury until the captured mercury eventually 
escapes and is emitted to the atmosphere. Also, raw mills do not run 
continuously. When the raw mill is turned off, this effect of raw meal 
adsorption of mercury is negated and mercury emissions appear to 
increase. However, the increase is actually mercury that would have 
previously been emitted but was captured by the raw meal and returned 
to the kiln. The net effect is that an in-line raw mill does not 
increase or reduce mercury emissions over the long term; it simply 
alters the time at which the mercury is released.
---------------------------------------------------------------------------

    \11\ More specifically, when the mill is on-line, the kiln gas 
containing volatilized mercury is used to sweep the mill of the 
finely ground raw feed particles. Since the mill temperature is only 
about 90 to 120 [deg]C during this operational mode, the fine PM can 
adsorb the mercury in the gas stream, and the particles containing 
condensed mercury are stored in the raw feed silos. This stored raw 
mix then is fed to the kiln. The captured mercury is again 
volatilized and returned in the gas stream to the raw mill, only to 
be captured again in the raw mill, as described above. This process 
continues as long as the raw mill is on-line, and the raw feed 
continues to adsorb additional mercury through this process.
---------------------------------------------------------------------------

    Mercury is also adsorbed on the CKD collected in the particulate 
control device, typically a fabric filter or an electrostatic 
precipitators (ESP). Because the collected CKD mainly consists of 
product, and sometimes small amounts of raw materials, the collected 
CKD is recycled back to the kiln to the extent possible. The portion 
that cannot be recycled to the kiln is either sent to a landfill, or 
used in some other manner (i.e. some type of beneficial use). Most 
facilities require that a portion of the CKD be removed from the kiln 
system rather than returned to the kiln. This is done to bleed the kiln 
system of alkali materials that build up as they circulate which would 
otherwise contaminate product and damage the kiln lining. This practice 
necessarily reduces the overall volume of mercury emitted by cement 
kilns, as noted by several commenters, since the entrained mercury in 
the CKD is no longer available for release from the kiln. The amount of 
reduction is kiln-specific, based on the level of alkali materials in 
the kiln's raw materials and required product specifications, and 
therefore not quantifiable on a national basis. Nor would kiln-by-kiln 
site-specific emission standards be warranted, for the same reasons 
that site-specific limits based on mercury levels on raw material and 
fuel inputs are not justified. EPA is instead determining that a floor 
standard for both existing and new sources is the work practice that 
cement kiln dust be removed from the kiln system at the point that 
recirculation causes adverse effect on product.
    d. Standards Based on Performance of Wet Scrubbers. There are at 
least five cement kilns that have limestone (wet) scrubbers installed 
for control of SO2. Commenters noted that based on 
experience with utility boilers, and other similar combustion devices, 
there is reason to expect that the scrubbers installed on cement kilns 
also remove oxidized mercury.
    To our knowledge, we obtained all the available data on wet 
scrubber controlled facilities after the comment period on the proposed 
amendments. This consists of data from 2004 and 2005 tests at two 
facilities measured exclusively at the scrubber outlet. These data 
range from 0.42 to 30 [mu]g/dscm. Variability of mercury emissions at 
the scrubber-equipped kilns for which we have multiple test data 
differs by orders of magnitude. These data fall within the range of 
test data from all kilns (those with wet scrubbers and those without 
wet scrubbers). We have no test data for mercury measured at the 
scrubber inlet. As a result, we cannot, on the basis of the current 
data, determine with absolute certainty (though we believe it is 
reasonably certain) if the outlet mercury emissions from the wet 
scrubber equipped kilns are a result of mercury removal by the 
scrubber, or simply reflect the amounts of mercury in the raw 
materials. We now discuss the implications of this information for 
purposes of existing and new source floors. Note that the following 
discussion assumes the scrubbers remove oxidized mercury for reasons 
discussed below.
    First, there are an insufficient number of wet-scrubber equipped 
kilns on which to base an existing source floor. The scrubber-equipped 
kilns would represent the best performing sources since data from other 
kilns simply reflect the mercury levels in kiln inputs on the day of 
the test. There are 158 operating kilns, and the information available 
to us indicates that only five of them are equipped with wet scrubbers. 
The median kiln of the top 12 percent would, therefore, not be a 
scrubber equipped kiln.\12\
---------------------------------------------------------------------------

    \12\ Choosing the median source for assessing an existing source 
floor here is a reasonable manner of determining ``the average 
emission limitation achieved by the best performing 12 percent of 
existing sources'' (section 112 (d)(3)). Not only can the statutory 
term ``average'' be reasonably interpreted to mean median, but it is 
appropriate to do so here in order not to adopt a de facto beyond 
the floor standard. If one were simply to combine the mercury 
emission levels of the kilns equipped with wet scrubbers with other 
kilns whose mercury levels reflect raw material and fuel mercury 
levels at the time of the performance test, the resulting limit 
would not be achievable over time by any source other than one with 
a wet scrubber. Ostensible best performers would consequently have 
to retrofit with back end control, since otherwise they could not 
consistently achieve the results of their own performance tests.
---------------------------------------------------------------------------

    However, for new sources mercury emissions would not be 
uncontrolled--solely dependent on raw material mercury content--but 
rather would reflect performance of ``the best controlled similar 
source'' (section 112 (d)(3)). A kiln so-equipped would thus have the 
best performance over time, since variability in mercury attributable 
to raw material and fuel inputs would be controlled in part.\13\
---------------------------------------------------------------------------

    \13\ That is, variability would no longer be purely a function 
of the happenstance of the amount of mercury in raw materials (and 
fossil fuels) used in the test condition. As explained more fully 
below, performance of wet scrubbers, however, is variable, based not 
only on operation of the device but on mercury levels in input 
materials. Wet scrubbers on utility boilers, for example, are 
documented to remove between 0 to 72 percent of incoming mercury. 
See Control of Mercury Emissions from Coal-Fired Electric Utility 
Boilers: Interim Report Including Errata available at http://www.epa.gov/nrmrl/pubs/600r01109/600r01109.htm.
 We should note, 

however, that because utility boilers do not have the significant 
levels of alkaline materials that are present in cement kilns, which 
alkaline materials would impede mercury oxidation and scrubber 
efficacy, we do not view utility boilers as a ``similar source'' for 
purposes of section 112(d)(1).
---------------------------------------------------------------------------

    We believe there is a reasonable basis that wet scrubbers remove 
oxidized mercury from cement kiln emissions. First, wet scrubbers are 
known to remove oxidized mercury in most combustion applications though 
removal rates vary. We have speciated mercury test data on two kilns 
that indicate that there is a significant amount of oxidized mercury in 
at least some cement kilns. See mercury emission test data for Holcim, 
Dundee, MI and Lafarge, Alpena, MI, in docket EPA-HQ-OAR-2002-0051. 
Second, the limited data we have from cement kilns equipped with wet 
scrubbers is among the lowest end-of-stack mercury data in our data 
base (although not the lowest), which could indicate that some removal 
mechanism is involved. An important caveat, however, is that these data 
are exclusively end-of-stack, without paired inlet concentrations. 
These data thus do not with absolute certainty demonstrate that mercury 
removal is occurring or how much.
    We estimated the performance of the best performing scrubber, and 
hence the new source MACT floor, to be 41 [mu]g/dscm (corrected to 7 
percent oxygen) using the following rationale. First, we limited the 
analysis to data from wet scrubber equipped kilns because, as just

[[Page 76524]]

discussed, the wet scrubber equipped kilns represent the best 
performing sources, regardless of their actual outlet emissions levels 
in individual performance tests. Second, we ranked all the wet scrubber 
mercury emissions with the raw mill off. We believe this is appropriate 
because the condition of raw mill off represents a normal operating 
mode for a cement kiln (albeit the operating mode when mercury 
emissions would be highest, as discussed above in section a.i). We then 
took the mean raw mill off value for mercury emissions from a cement 
kiln in our (limited) data base, and added to it a variability factor 
to account for normal variation in emissions. This variability factor 
is the standard deviation of the data multiplied by 2.326 (the z 
statistic) to produce the 99th confidence interval. We looked to all of 
the data, rather than to the data from the single lowest emitting kiln, 
because there are too few data points from that kiln (or from any one 
kiln) to estimate that kiln's variability. Given that variability is 
known to occur, we believe that this is the best approximation of 
variability of the best performing kiln presently available.
    The result of this analysis is a new source floor of 41 [mu]g/dscm 
that must be met continuously (raw mill on and raw mill off) (see 
further discussion in section A.3 below). This is an emissions limit 
that we believe will not be exceeded 99 percent of the time by the best 
performing kiln whose performance is used to set the standard.
    Because of the limited performance data characterizing performance 
of the lowest-emitting scrubber-equipped kiln, the rule also contains 
an alternative new source mercury floor. The best performing kiln is 
equipped with a wet scrubber, although there could be questions about 
its performance over time. Therefore, if a new source installs a 
properly designed and operated wet scrubber, and is unable to achieve 
the 41 [mu]g/dscm standard, then whatever emission level the source 
achieves (over time, considering all normal sources of variability) 
would become the floor for that source. Based on the design of the wet 
scrubber that is the basis of the new source floor, this would be a 
packed bed or spray tower wet scrubber with a minimum liquid-to-gas 
ratio of 30 gallons per thousand cubic feet of exhaust gas.
    In sum, we conclude that floors for mercury for all existing cement 
kilns should be to remove accumulated mercury-containing cement kiln 
dust from the system at the point product quality is adversely 
affected. The floor for new sources is to utilize this same work 
practice, and in addition, to meet a standard of either 41 [mu]g/dscm 
or a site-specific limit based on performance of a properly designed 
and operated wet scrubber.
    As just explained, the mercury data on which the new source floor 
is based are not only limited, but fails to definitively answer the 
critical question of whether wet scrubbers are removing oxidized 
mercury, and, if so, to what extent. We are taking immediate steps to 
address this issue and augment the data base. In an action published 
elsewhere in this Federal Register, we are granting reconsideration of 
the new source standard adopted in this rule, both due to substantive 
issues relating to performance of wet scrubbers and because information 
about their performance in this industry has not been available for 
public comment. We also have initiated actions to obtain inlet and 
outlet test data for cement kilns equipped with wet scrubbers in order 
to determine if these controls remove mercury, and to what extent. In 
addition, we are committing to completing this reconsideration process 
within one year from December 20, 2006.
2. Beyond-the-Floor Determinations
    During development of the original NESHAP for Portland cement 
manufacturing, we conducted MACT floor and beyond-the-floor analyses 
for kiln and in-line kiln/raw mill mercury emissions (63 FR 14182, 
March 24, 1998 and 64 FR 31898, June 14, 1999). We also conducted a 
beyond-the-floor analysis for mercury, based on the performance of 
activated carbon injection with an additional PM control device. Costs 
for the system would include the cost of the carbon injection system 
and an additional fabric filter (FF) to collect the carbon separately 
from the CKD. Based on the low levels of mercury emissions from 
individual Portland cement kilns, as well as the high cost per ton of 
mercury removed by the carbon injection/FF system, we determined that 
this beyond-the-floor option was not justified (63 FR 14202, March 24, 
1998).
    At proposal, EPA again concluded tentatively that a beyond the 
floor standard based on performance of activated carbon is not 
justified (70 FR 72335). We have since reevaluated beyond-the-floor 
control options for mercury emissions. This evaluation included both 
process changes and add-on control technology.
    There are two potential feasible process changes that have the 
potential to affect mercury emissions. These are removing CKD from the 
kiln system and, for the subcategory of kilns that currently use fly 
ash as a raw material, replacing the fly ash with a lower mercury raw 
material. Substituting raw materials or fossil fuels with lower-mercury 
inputs could in theory reduce mercury emissions, but this alternative 
is infeasible for the reasons explained at 70 FR 72333-72334.
    Generally, once mercury enters a kiln system, it has five potential 
fates: it may remain unchanged and become part of the final product; it 
may react with raw materials and exit the kiln in the clinker; it may 
vaporize in the high temperature of the kiln and/or preheater; it may 
condense or react with the cement kiln dust and be removed from the 
system; or it may exit the kiln system in vapor form or be adsorbed to 
a dust particle through the stack. In general, mercury in the fuel 
becomes volatilized near the kiln's combustion zone and is carried 
toward the feed end of the system along with combustion gases. Some of 
the mercury compounds pass through the entire system and exit in vapor 
phase through a stack. However, as the flue gas cools, some mercury may 
adsorb/condense onto dust particles in the cooler regions of the kiln 
system. Much of this dust containing condensed mercury would then be 
captured by the PM control device and for most kiln systems, returned 
to the kiln.
    We evaluated, requiring a facility to further reduce the recycling 
of CKD beyond the wastage already needed to protect product quality, 
the floor for both existing and new sources. For a 600,000 tpy (tpy) 
kiln the estimated total annual cost would be $3.7 million just for 
replacement of CKD (which is actually product) and disposal of 
additional solid waste. This cost does not account for the increased 
raw materials costs and energy costs associated with reducing the 
recycling of the CKD. The mercury emissions reduction would range from 
0.012 to 0.055 tpy based on assumed CKD mercury concentrations of 0.33 
and 1.53 parts per million (ppm) respectively. The cost per ton of 
mercury reduction would range from $67 million to $308 million. See 
Costs and Impacts of Wasting Cement Kiln Dust or Replacing Fly Ash to 
Reduce Mercury Emissions in docket EPA-HQ-OAR-2002-0051. We note that 
the median value for the mercury content of recycled CKD for one study 
was only 0.053 ppm. See the report Mercury and Lead Content in Raw 
Materials in docket EPA-HQ-OAR-2002-0051. This would indicate that for 
the majority of the facilities the costs per ton would be even higher 
that those presented above. In addition, we

[[Page 76525]]

estimate that wasting 50 percent of the recycled CKD would reduce the 
energy efficiency of the process by six percent due to the need to 
process and calcine additional feed to replace the wasted CKD. It is 
possible that in some cases the wasted cement kiln dust could be mixed 
with the cement product rather than landfilled, or that some other 
beneficial use could be found. This would reduce the costs and non-air 
adverse impacts of this option. However, there are currently barriers 
to directly mixing CKD with clinker due to product quality and product 
specification issues. We do not have data available to evaluate the 
potential for beneficial use of the CKD. Based on these costs, the 
adverse energy impacts, and the increased adverse waste disposal 
impacts (see 64 FR 45632, 45635-36 (Aug. 20, 1999) for examples of 
potential hazards to human health and the environment posed by disposal 
of cement kiln dust), we do not believe this beyond-the-floor option is 
justified and therefore are not selecting it.
    As previously noted, for the subcategory of facilities that use 
utility boiler fly ash as a kiln feed we determined that the current 
use represented the MACT floor. We considered two beyond-the-floor 
options for this subcategory. One option was to ban the use of any fly 
ash if it resulted in a mercury emissions increase over a raw material 
baseline, and the second was to only ban the use of fly ash whose 
mercury content had been artificially increased through the use of a 
sorbent to capture mercury in the utility boiler flue gas.
    If we were to ban the use of utility boiler fly ash for any case 
where it has been shown to increase mercury emissions from the kiln 
over a raw material baseline, facilities would have to revert to using 
their previous raw materials, or to find alternative raw materials that 
provide the same chemical constituents as the fly ash. As previously 
noted, if a facility replaces their shale or clay with fly ash, the 
quarry for that material may now be closed and it may not be possible 
to cost-effectively obtain the previously used raw materials. And for 
at least two new facilities, the original raw materials used at startup 
will include fly ash, so there is no previously used material with 
which to compare the mercury content of the fly ash. Due to the site 
specific costs associated with raw materials, we don't have any data to 
calculate the costs of the beyond-the-floor option for the industry as 
a whole. In one example, we estimated the cost as approximately $136 
million per ton of mercury reduction. See Costs and Impacts of Wasting 
Cement Kiln Dust or Replacing Fly Ash to Reduce Mercury Emissions in 
docket EPA-HQ-OAR-2002-0051. Also, this option would mean that all the 
fly ash currently being used as a cement kiln feed would now 
potentially have to be landfilled. This would generate an additional 3 
million tpy of solid waste, with potential adverse health and 
environmental impacts associated with management of these wastes. There 
would also be adverse environmental air and non-air quality health and 
environmental impacts associated with the mining of additional raw 
materials that would have to be utilized. In addition, the overall kiln 
efficiencies (i.e. the amount of fuel required per ton of clinker 
produced) at the facilities using fly ash would be expected to decrease 
if the fly ash were replaced with shale or clay. This decrease may be 
as large as 10 percent (See Site Visit to Lafarge Cement in Alpena 
Michigan in the docket).
    Based on the cost, energy, and adverse non-air quality health and 
environmental impacts, we believe that banning the current use of 
utility boiler fly ash is not justified.
    We also separately evaluated the use of fly ash from a utility 
boiler where activated carbon, or some other type of sorbent injection, 
has been used to collect mercury. This practice does not currently 
occur. See 70 FR 72344 (voicing concern about potential for increased 
mercury emissions from cement kilns were such fly ash to be used). The 
mercury concentration in this type of fly ash will vary widely. 
However, full scale testing of fly ash from utility boilers using 
various sorbent injection processes has indicated there is a potential 
for sorbent injection to significantly increase fly ash mercury content 
(Characterization of Mercury-Enriched Coal Combustion Residues from 
Electric Utilities Using Enhanced Sorbents for Mercury Control in the 
docket EPA-HQ-OAR-2002-0051). Testing to date has shown increases by a 
factor of 2 to 10, and in one case of a very low mercury fly ash the 
increase was by a factor of 70.
    Data from 16 cement facilities currently using fly ash not 
reflecting sorbed mercury showed mercury concentrations in the fly ash 
from 0.002 ppm to 0.685 ppm with a median of 0.136 ppm. Data on the fly 
ash mercury content of currently operating utility boilers testing 
sorbent injection showed levels ranging from 0.071 ppm up to 1.529 ppm 
with a median level of 1.156 ppm, significantly higher than the fly ash 
currently in use. Therefore, we see a potential for fly ash with 
enhanced mercury content due to sorbent injection at the utility site 
to increase mercury emissions from cement kilns, and for the increase 
to be much more significant than emissions attributable to the current 
fly ash being used.
    We do not see a ban on the use of this type of fly ash as 
significantly affecting the overall current beneficial uses of fly ash. 
First, we do not anticipate the widespread use of activated carbon 
injection ACI in the utility industry until 2010 or later. Therefore, 
both the cement industry and the utility industry will have a 
significant amount of time to adjust to this requirement. Second, a 
utility boiler that decides to apply ACI for mercury control has the 
option of collecting the fly ash from sorbent injection systems 
separately from the rest of the facility's fly ash (e.g., EPRI'S 
TOXECON system). Therefore, the utility boiler could continue to supply 
non-sorbent fly ash to a cement kiln even after the application of ACI 
for mercury control. Finally, technology is being developed that would 
allow the mineral-rich portion of fly ash to be separated from the high 
carbon/high mercury portion.
    Based on these factors, we are banning the use of utility boiler 
fly ash in cement kilns where the fly ash mercury content has been 
increased through the use of activated carbon or any other sorbent 
unless the facility can demonstrate that the use of that fly ash will 
not result in an increase in mercury emissions over baseline emissions 
(i.e., emissions not using the mercury increased fly ash). The facility 
has the burden of proving there has been no emissions increase over 
baseline. This requirement, adopted as a beyond-the-floor control, 
applies to both existing and new sources.
    We also reevaluated our analysis of potential control options based 
on add-on control technology. These were control options based on the 
use of a limestone scrubber, and ACI.
    As previously noted there are at least five cement kilns that have 
limestone (wet) scrubbers. As discussed in section IV.A.1.d above, 
there is a reasonable basis for believing that the wet scrubbers remove 
the oxidized mercury. There are no data available to allow us to 
definitively estimate the percent reduction expected. We performed a 
cost analysis based on an assumed mercury removal efficiency of 42 
percent, which is transferred (solely for purposes of analysis) \14\ 
from

[[Page 76526]]

performance of wet scrubbers in the utility boiler category and 
represents the greatest degree of removal one could expect to be 
consistently achieved for Portland cement kilns. We also note that the 
wet scrubber will achieve cobenefits of reducing SO2 and 
dioxins (although dioxin removal would be relatively modest since any 
removal would be incremental to that required by the existing MACT 
dioxin standard for Portland cement kilns). The results of that 
analysis for an existing model large kiln are as follows:
---------------------------------------------------------------------------

    \14\ As explained in section 1.d, there are no data to 
definitively state that the percent reduction achieved by wet 
scrubbers in the utility industry are representatie of the percent 
reduction in the Portland cement source category. We used this 
figure in beyond-the-floor analyses as an upper bound best case for 
potential emission reductions.

                          Table 1.--Packed Bed Scrubber--Costs and Emission Reductions
----------------------------------------------------------------------------------------------------------------
                                                                      Emissions reduction
Clinker production in  Total annualized cost -------------------------------------------------------------------
      tpy (tpy)                ($/yr)               SO2 (tpy)              D/F (g/yr)            Hg (lb/yr)
----------------------------------------------------------------------------------------------------------------
          600,000              1,542,000                    297                   0.11               16.8-147
----------------------------------------------------------------------------------------------------------------

Based on this analysis the cost per ton of mercury removed ranges from 
$21 million per ton to $184 million per ton, a result that is not at 
all cost effective. In addition, a wet scrubber for a large kiln will 
generate approximately 45,500 tpy of solid waste and require 
approximately 980,000 kilowatt hour per year (kWhr/year) of 
electricity.
    Based on the significant cost impacts per ton of emission 
reduction, and the adverse energy and solid waste impacts, and the 
uncertainty of the actual mercury emission reductions, we do not 
consider this control option to be reasonable for existing sources.
    At proposal, EPA discussed and rejected a beyond-the-floor option 
based on the use of activated carbon injection. See 70 FR 72335. 
Commenters noted that our costs for ACI had not been updated from the 
costs calculated in development of the original NESHAP. In response, we 
have now updated our ACI costs based on more recent information. The 
total annualized costs for a large new or existing kiln ranges from 
$510,000 to $676,000 per year. Assuming an 80 percent reduction in 
mercury emissions, the cost per ton of mercury removal ranged from $4 
million to $42 million per ton for existing kilns. The wide range in 
cost per ton of removal is mainly influenced by the baseline mercury 
emissions. Based on the wide variation we have seen in actual mercury 
emissions in this source category, the actual cost per ton would also 
vary widely from site to site as shown above.
    We also evaluated a beyond-the-floor option for new kilns based on 
combining ACI and a wet scrubber. The incremental cost of ACI in this 
application is $9 to $89 million per ton of mercury removed, which we 
regard as a very high cost.
    Our cost estimates assumed 80 percent emissions reduction for 
mercury. Though we are reasonably certain that ACI will remove mercury 
from cement kiln exhaust gas, we have no data on the actual expected 
removal efficiency. Data are available for one emissions test on a 
cement kiln burning hazardous waste. In this test the mercury removal 
efficiency averaged 89 percent removal. However, the inlet mercury 
concentration during the test varied from 65 to 267 [mu]g/dscm. A 
review of the data for the individual test runs implies that the 
percent reduction decreases as the inlet concentration decreases. 
Almost all the non-hazardous waste cement kilns tested had mercury 
concentrations well below 65 [mu]g/dscm. Therefore, the long term 
performance of ACI on mercury emissions from cement kilns is very 
uncertain. We also note that the application of ACI to a cement kiln 
(either alone or in combination with a wet scrubber) will generate 
approximately 1,600 tpy of solid waste for a new or existing large 
kiln. Recycling of the waste would be unlikely due to the toxics 
content.
    For existing sources we rejected a control option based on the 
performance of ACI due to the significant cost per ton of mercury 
removed, increased energy use, and the adverse non-air quality health 
and environmental impacts (in the form of additional mercury and 
organic-laden waste generated). For new sources we rejected the option 
based on the performance of ACI combined with a wet scrubber for 
essentially the same reasons: significant cost per ton of mercury 
removed, increased energy use and adverse non-air quality health and 
environmental impacts. For both new and existing sources we also 
rejected this control option due to the uncertainty of the actual 
performance levels achieved, which leads to uncertainty of the actual 
cost per ton of mercury emissions reduction. We also note that the 
application of ACI potentially could result in a THC emission reduction 
of up to 117 tpy per kiln, though in most cases the reduction would be 
approximately 30 tpy or less. This THC emissions reduction is based on 
an assumed control efficiency of 50 percent. We do not see these small 
THC emission reductions (of which organic HAP are a small subset) to be 
a reason to alter our tentative decision at proposal that a standard 
based on performance of ACI is not justified as a beyond-the-floor 
control option.
    Finally, for greenfield new sources (sources being newly built at a 
site without other cement kilns), we considered the option of requiring 
such a kiln to be sited at a low-mercury quarry. This concept has 
intuitive appeal: such a new kiln is not tied to an existing source of 
limestone, and so can choose where to be sited. The difficulty is in 
quantifying this type of standard. We cannot presently quantify what 
`high mercury quarry' or `low mercury quarry' means, and cannot 
responsibly select an arbitrary number that might make it impossible to 
build a new cement kiln in major parts of the country.
3. Conclusion
    In sum, we conclude that the standards for mercury for all existing 
cement kilns are to remove accumulated mercury-containing cement kiln 
dust from the system at the point product quality is adversely 
affected. The standard for new sources is to utilize this same work 
practice, and in addition, to meet a standard of either 41 [mu]g/dscm 
or a site-specific limit based on performance of a properly designed 
and operated wet scrubber.
    In addition, we are banning the use of utility boiler fly ash in 
cement kilns where the fly ash mercury content has been increased 
through the use of activated carbon or any other sorbent unless the 
facility can demonstrate that the use of that fly ash will not result 
in an increase in mercury emissions over baseline emissions (i.e., 
emissions not using the mercury increased fly ash).

[[Page 76527]]

    Because the final standard is more stringent than the standard EPA 
proposed, the compliance date for sources which commenced construction 
after December 2, 2005, and before promulgation of this final rule is 
three years from December 20, 2006. See section 112(i)(2). New sources 
that commence construction after the date of promulgation of today's 
action must comply with the final rule upon start-up. However, as we 
are reconsidering the new source mercury standard and plan to take 
final action on that reconsideration in no more than a year and as 
construction of a new kiln generally takes at least 20-24 months, it is 
unlikely that any new source will be subject to the standard before 
completion of reconsideration.
    We are also requiring that new sources demonstrate compliance by 
doing mercury emission testing with the raw mill off and with the raw 
mill on. The reason to test under both conditions is that (as explained 
in section A.1.c above) one other operation factor besides wet scrubber 
performance affecting emissions is the recycling of CKD. A facility 
could cut off CKD recycling for purposes of meeting the emission limit 
during testing with raw mill off, and then start recycling after the 
test which could result in the emissions limit being exceeded. We could 
simply limit CKD recycling to the level during the raw mill off test, 
but we believe this would potentially and needlessly restrict the 
ability of a facility to recycle CKD during raw mill on operation. 
During the test under each condition, the facility must record the 
amount of CKD recycle. The amount of CKD recycle becomes an operating 
limit not to be exceeded.
    The limit for new sources adopted here also applies to both area 
and major new sources. We have applied this limit to area sources 
consistent with section 112(c)(6).
    For facilities that elect to meet mercury emissions limits using 
ACI, we are incorporating the operating and monitoring requirements for 
ACI that are applicable when ACI is used for dioxin control.

B. Determination of MACT for HCl Emissions

    In developing the 1999 Portland Cement NESHAP we concluded that no 
add-on air pollution controls were being used whose performance could 
be used as a basis for the MACT floor for existing Portland cement 
plants. For new source MACT, we identified two kilns that were using 
alkaline scrubbers for the control of SO2 emissions. But we concluded 
that because these devices were operated only intermittently, their 
performance could not be used as a basis for the MACT floor for new 
sources. Alkaline scrubbers were then considered for beyond-the-floor 
controls. Using engineering assessments from similar technology 
operated on municipal waste combustors and medical waste incinerators, 
we estimated costs and emissions reductions. Based on the costs of 
control and emissions reductions that would be achieved, we determined 
that beyond-the-floor controls were not warranted (63 FR 14203, March 
24, 1998).
    In the proposed amendments, we reexamined establishing a floor for 
control of HCl emissions from new Portland cement sources. Since 
promulgation of the NESHAP, wet scrubbers have been installed and are 
operating at a minimum of five Portland cement plants. See section 
IV.A.1.d above. For the reasons described above, this is an 
insufficient number of scrubbers on which to base an existing source 
floor for this category (id.). We did, however, propose to base the 
floor for new sources on the performance of continuously operated 
alkaline scrubbers, and proposed emissions levels of 15 ppmv at the 
control device outlet, or a 90 percent HCl emissions reduction measured 
across the scrubber, as the new source floor.
    We also reexamined the MACT floor for existing sources. The only 
potential controls identified as a floor option was the operation of 
the kiln and PM control device themselves. Because the kiln and PM 
control system contain large amounts of alkaline CKD, the kilns 
themselves remove a significant amount of HCl (which reacts with the 
CKD and is captured as particulate). See 70 FR 72337 and 69 FR 21259 
(April 20, 2004). We proposed as a floor the operation of the kiln and 
PM control as a work practice standard.
    We also evaluated requiring the use of an alkaline scrubber as a 
beyond-the-floor control option for existing sources. We found that the 
costs and non-air quality health and environmental impacts were not 
reasonable for the emissions reductions achieved.
    We also solicited comment on adopting alternative risk-based 
emission standards for HCl pursuant to section 112(d)(4) of the CAA (70 
FR 72337). We suggested two possible approaches for establishing such 
standards. Under the first approach an alternative risk-based standard 
would be based on national exposure standards determined by EPA to 
ensure protection of public health with an ample margin of safety, and 
to be protective of the environment. For reasons discussed below we 
have decided to adopt this approach. Under the second approach, which 
we are not adopting, site specific risk analyses would be used to 
establish standards on a case-by case basis.
    After careful consideration of the comments on the proposed 
amendments, we are not requiring control of HCl emissions from cement 
kilns under section 112(d). Under the authority of section 112(d)(4) of 
the CAA, we have determined that no further control is necessary 
because HCl is a ``health threshold pollutant,'' and human health is 
protected with an ample margin of safety at current HCl emission 
levels. The following explains the statutory basis for considering 
health thresholds when establishing standards and the basis for today's 
decision, including a discussion of the risk assessment conducted to 
support the decision.
    Section 112 of the CAA includes exceptions to the general statutory 
requirement to establish emission standards based on MACT. Of relevance 
here, section 112(d)(4) allows us to develop risk-based standards for 
HAP ``for which a health threshold has been established'' provided that 
the standards achieve an ``ample margin of safety.'' Therefore, we 
believe we have the discretion under section 112(d)(4) to develop 
standards which may be less stringent than the corresponding 
technology-based MACT standards for threshold hazardous air pollutants 
emitted by some source categories. See 67 FR 78054, December 20, 2002 
and 63 FR 18765, April 15, 1998.
    In evaluating potential standards for HCl for this source category, 
we seek to assure that emissions from every source in the category 
result in exposures not causing adverse effects, with an ample margin 
of safety, even for an individual exposed at the upper end of the 
exposure distribution. The upper end of the exposure distribution is 
calculated using the ``high end exposure estimate,'' defined as a 
plausible estimate of individual exposure for those persons at the 
upper end of the exposure distribution, conceptually above the 90th 
percentile, but not higher than the individual in the population who 
has the highest exposure. We believe that assuring protection to 
persons at the upper end of the exposure distribution is consistent 
with the ``ample margin of safety'' requirement in section 112(d)(4).
    Our decision not to develop standards for HCl from cement kilns is 
based on the following. First, we consider HCl to be a threshold 
pollutant. See 63 FR 18767, 67 FR 78054, and 70 FR 59407, October 12, 
2005. Second, we have defined threshold values for HCl in the

[[Page 76528]]

form of an Inhalation Reference Concentration (RfC) and acute exposure 
guideline level (AEGL). Third, HCl is emitted from cement kilns in 
quantities that result in human exposure in the ambient air at levels 
well below these threshold values with an ample margin of safety. 
Finally, there are no adverse environmental effects associated with HCl 
emissions from cement kilns. The bases and supporting rationale for 
these conclusions are as follows.
    For the purposes of section 112(d)(4), several factors are 
considered in our decision on whether a pollutant should be categorized 
as a health threshold pollutant. These factors include evidence and 
classification of carcinogenic risk and evidence of noncarcinogenic 
effects. For a detailed discussion of factors that we consider in 
deciding whether a pollutant should be categorized as a health 
threshold pollutant, please see the April 15, 1998, Federal Register 
document (63 FR 18766). In the April 15, 1998, action cited above, we 
determined that HCl, a Group D pollutant, is a health threshold 
pollutant for the purpose of section 112(d)(4) of the CAA (63 FR 
18753).
    The Portland Cement Association (PCA) conducted a risk assessment 
to determine whether the emissions of HCl from cement kilns at the 
current baseline levels resulted in exposures below the threshold 
values for HCl. We reviewed the risk assessment report prepared by the 
PCA and believe that it uses a reasonable and conservative methodology, 
is consistent with EPA methodology and practice, and reaches a 
reasonable conclusion that current levels of HCl emissions from cement 
kilns would be well under the threshold level of concern even for 
assumed worst-case human receptors.
    The PCA analysis evaluated long-term and short-term ambient air 
concentrations resulting from emissions of HCl from Portland cement 
kilns in order to quantify potential non-cancer risks associated with 
such emissions, as well as to characterize potential ecological effects 
of those emissions. The approach is based on the USEPA guidance 
document entitled ``A Tiered Modeling Approach for Assessing the Risks 
Due to Sources of Hazardous Air Pollutants'' (USEPA 1992) (Tiered 
Modeling Approach) and is consistent with EPA risk characterization 
guidance ``Air Toxics Risk Assessment Reference Library--Volume 2--
Facility-Specific Assessment'' (USEPA, 2004). The PCA conducted 
dispersion modeling for 67 cement plants and 112 cement kilns, 
representing about two-thirds of all operating cement plants in the 
U.S., using stack parameter data provided by cement companies and 
conservative assumptions regarding (among other factors) HCl stack 
concentrations, operating conditions, receptor locations, and 
dispersion characteristics. The kilns for which data were provided 
cover a full range of kiln types, operating conditions, and stack 
parameters. The three-tiered modeling approach consists of:
     Tier 1--Lookup tables.
     Tier 2--Screening dispersion modeling.
     Tier 3--Detailed dispersion modeling.
    The concentration estimates from each modeling tier should be more 
accurate and less conservative than the previous one. As a result, the 
level of complexity of the modeling and data input information required 
for each tier is greater than for the previous tier. If a plant showed 
emissions below the threshold concentration in any tier, that plant was 
not included in the next tier of modeling.
    In order to evaluate potential health impacts it is necessary to 
establish long term concentration thresholds. The RfC is a long-term 
threshold, defined as an estimate of a daily inhalation exposure that, 
over a lifetime, would not likely result in the occurrence of 
significant noncancer health effects in humans. We have determined that 
the RfC for HCl of 20 micrograms per cubic meter ([mu]g/m3) 
is an appropriate threshold value for assessing risk to humans 
associated with exposure to HCl through inhalation (63 FR 18766, April 
15, 1998). Therefore, the PCA used this RfC as the threshold value in 
their exposure assessment for HCl emitted from cement kilns.
    The general approach was that actual release characteristics were 
used for stack height, stack diameter, exit temperature, and exit 
velocity, based on information provided by the individual facilities 
modeled by the PCA. The analyses performed under each tier assumed 
worst case operating scenarios, such as maximum production rate and 24 
hours per day, 365 days per year operation, and that all kilns were 
located 10 meters from the property boundary line. HC1 emission rates 
were assumed to be 130 ppmv for all kiln types. This is an extremely 
conservative number. Hydrogen chloride emission rates are below 10 ppmv 
at most facilities, and the highest value for which we have data is 
below 45 ppmv. In the Tier 2 analyses, worse case metrological 
conditions were assumed. Further, it is important to note that these 
predicted impacts are located adjacent to facility property lines, many 
times in locations where chronic exposure is not expected. Impacts at 
potential residential locations would be expected to be significantly 
below those presented in the analysis.
    The PCA study generated estimates of chronic (annual average) 
concentrations for comparison to the relevant health reference values 
or threshold levels. Chronic exposures were compared to the RfC of 20 
[mu]g/m3 for long-term continuous exposure.
    Noncancer risk assessments typically use a metric called the Hazard 
Quotient (HQ) to assess risks of exposures to noncarcinogens. The HQ is 
the ratio of exposure (or modeled concentration) to the health 
reference value or threshold level (i.e., RfC or REL). HQ values less 
than 1 indicate that exposures are below the health reference value or 
threshold level and are likely to be without appreciable risk of 
adverse effects in the exposed population. HQ values above 1.0 do not 
necessarily imply that adverse effects will occur, but that the 
potential for risk of such effects increases as HQ values exceed 1.0.
    For the PCA assessment, if the HQ was found to be less than one for 
any of the tiers using conservative defaults and modeling assumptions, 
the analysis concluded with that tier. On the other hand, if the HQ 
exceeded one, analysis proceeded to subsequent tiers.
    The Tier 1 modeling resulted in an HQ above 1 for most facilities. 
Therefore, a Tier 2 analysis was required. In the Tier 2 analysis, all 
facilities except for five showed an HQ below 1.
    For the five facilities with an HQ above 1, additional data were 
obtained on the actual HCl and stack moisture concentrations at these 
facilities and the Tier 2 modeling analysis was rerun. The refined Tier 
2 analysis resulted in HQ values of 0.30 or less for all five 
facilities.
    Thus, we have evaluated and are comfortable with PCA's calculations 
and feel confident that exposures to HCl emissions from the facilities 
in question are unlikely to ever exceed an HQ of 1.0. Therefore, we 
believe that the predicted exposures from these facilities should still 
be protective of human health with an ample margin of safety. Put 
another way, total exposures for nearby residents would not exceed the 
short-term or long-term health based threshold levels or health 
reference values. Similarly, based on the PCA analysis we believe that 
the acute exposure to HC1 for these facilities would not exceed the 
short-term, health-based threshold level.
    The standards for emissions must also protect against significant 
and widespread adverse environmental

[[Page 76529]]

effects to wildlife, aquatic life, and other natural resources. The PCA 
did not conduct a formal ec0ological risk assessment. However, we have 
reviewed publications in the literature to determine if there would be 
reasonable expectation for serious or widespread adverse effects to 
natural resources.
    We consider the following aspects of pollutant exposure and 
effects: toxicity effects from acute and chronic exposures to expected 
concentrations around the source (as measured or modeled), persistence 
in the environment, local and long-range transport, and tendency for 
biomagnification with toxic effects manifest at higher trophic levels.
    No research has been identified for effects on terrestrial animal 
species beyond that cited in the development of the HCl RfC. Modeling 
calculations indicate that there is little likelihood of chronic or 
widespread exposure to HCl at concentrations above the threshold around 
cement manufacturing plants. Based on these considerations, we believe 
that the RfC can reasonably be expected to protect against widespread 
adverse effects in other animal species as well.
    Plants also respond to airborne HCl levels. Chronic exposure to 
about 600 [mu]g/m3 can be expected to result in discernible effects, 
depending on the plant species. Further, in various species given 
acute, 20 minute exposures of 6,500 [mu]g/m3, field studies report 
different sensitivity to damage of foliage. The maximum modeled long-
term HCl concentration (less than 100 [mu]g/m3) is well 
below the 600 [mu]g/m3 chronic threshold, and the maximum 
short-term HCl concentration (less than 1600 [mu]g/m3) is 
well below the 6,500 [mu]g/m3 acute exposure threshold. 
Therefore, no adverse exposure effects on plant species are 
anticipated.
    HCl is not considered to be a strongly persistent pollutant or one 
where long range transport is important in predicting its ecological 
effects. In the atmosphere, HCl can be expected to be absorbed into 
aqueous aerosols, due to its great affinity for water, and removed from 
the troposphere by rainfall. Toxic effects of HCl to aquatic organisms 
would likely be due to the hydronium ion, or acidity. Aquatic organisms 
in their natural environments often exhibit a broad range of pH 
tolerance. Effects of HCl deposition to small water bodies and to soils 
will primarily depend on the extent of neutralizing by carbonates or 
other buffering compounds. Chloride ions are essentially ubiquitous in 
natural waters and soils so minor increases due to deposition of 
dissolved HCl will have much less effect than the deposited hydronium 
ions.
    In conclusion, acute and chronic exposures to expected HCl 
concentrations around cement kilns are not expected to result in 
adverse environmental toxicity effects. HC1 is not persistent in the 
environment. Effects of HCl on ponds and soils are likely to be local 
rather than widespread. Finally, HCl is not believed to result in 
biomagnification or bioaccumulation in the environment. Therefore, we 
do not anticipate any adverse ecological effects from HCl.
    The results of the exposure assessment showed that exposure levels 
to baseline HCl emissions from cement production facilities are well 
below the health threshold value. Additionally, the threshold values, 
for which the RfC and AEGL values were determined to be appropriate 
values, were not exceeded when considering conservative estimates of 
exposure resulting from cement kiln emissions as well as considering 
background exposures to HCl and therefore, represent an ample margin of 
safety. Furthermore, no significant or widespread adverse environmental 
effects from HCl are anticipated. Therefore, under authority of section 
112(d)(4), we have determined that further control of HCl emissions 
from new or existing cement manufacturing plants under section 112(d) 
is not necessary.

C. Determination of MACT for THC Emissions

1. Floor Determinations
    THC serve as a surrogate for non-dioxin organic HAP emissions for 
this source category. During the development of the 1999 Portland 
Cement NESHAP, EPA identified no add-on air pollution control 
technology being used in the Portland cement industry whose performance 
could be used as a basis for establishing a MACT floor for controlling 
THC emissions from existing sources. EPA did identify two kilns using a 
system consisting of a precalciner (with no preheater), which 
essentially acts as an afterburner to combust organic material in the 
feed. The precalciner/no preheater system was considered a possible 
basis for a beyond-the-floor standard for existing kilns and as a 
possible basis for a MACT floor for new kilns. However, this system was 
found to increase fuel consumption relative to a preheater/precalciner 
design, to emit six times as much SO2, two and one half 
times as much NOX, and 1.2 times as much CO2 as a 
preheater/precalciner kiln of equivalent clinker capacity. Taking into 
account the adverse energy and environmental impacts, we determined 
that the precalciner/no preheater design did not represent MACT (63 FR 
14202, March 24, 1998). We also considered feed material selection for 
existing sources as a MACT floor technology and concluded that this 
option is not available to existing kilns, or to new kilns located at 
existing plants because these facilities generally rely on existing raw 
material sources located close to the source due to the cost of 
transporting the required large quantities of feed materials. However, 
for new greenfield kilns, feed material selection as achieved through 
appropriate site selection and feed material blending is demonstrated 
and is the basis for new source MACT (63 FR 14202, March 24, 1998).
    In our proposed amendments we reexamined MACT for THC for both new 
and existing facilities. We proposed to adopt the same standards for 
Portland cement kilns as are applicable to kilns that fire hazardous 
waste (40 CFR 63.1220(a)(5)). Those standards are based on using good 
combustion conditions to destroy hazardous air pollutants in fuels. Our 
rationale for proposing to adopt these standards was that the THC and 
carbon monoxide (CO) standards guarantee that the kiln will operate 
under good combustion conditions and will minimize formation (and 
hence, emissions) of non-dioxin organic HAP from fuel combustion. We 
believed that the control of THC emissions from cement kilns which do 
not fire hazardous waste should be no more difficult to control than 
emissions for kilns that do fire hazardous waste because GCP are 
maintainable by either type of kiln, and the hazardous waste cement 
kilns would be the more challenged in that regard. Because we had no 
data upon which to set a different standard, and because we believed 
these levels were indicative of good combustion in any case, the 
adoption of the standards for cement kilns firing hazardous waste was 
deemed appropriate.
    We continue to believe that good fuel combustion conditions are 
indicative of the performance of the median of the best performing 12 
percent of existing sources for controlling non-dioxin organic HAP. 
However, based on comments received on the proposed amendments, and 
additional emission data analysis, we believe our proposed quantified 
method of monitoring good fuel combustion, i.e. setting specific THC or 
CO levels, was flawed.
    Industry commenters had noted that the majority of the THC 
emissions from a cement kiln main stack result from the

[[Page 76530]]

introduction of feed materials into the cold end of the kiln. These 
emissions are essentially a function of the organic content of the raw 
materials, and cannot be controlled using GCP, which is the basis of 
our MACT floor. At proposal we agreed with this assessment (and 
continue to agree with it), but believed that the fact that cement 
kilns that burn hazardous waste can meet these standards indicated that 
the proposed level could be met by all cement kilns under good 
combustion conditions, even considering the fact that good combustion 
cannot control THC or CO emissions emanating from organic materials in 
the feed. We also believed that by allowing a facility to monitor CO as 
a surrogate for THC, we had provided sufficient flexibility to account 
for variations in feed material organic content.
    We have reevaluated these assumptions. First, we obtained 
additional THC emission data from several facilities. These data 
demonstrate that there are certain cement facilities where THC 
emissions, with no indication of poor fuel combustion practices, exceed 
20 ppmv. The data also indicate that achieving the 100 ppmv CO level, 
even for cement kilns with low organic content feed and good fuel 
combustion conditions, is not possible without use of a control device. 
See Lehigh CO and THC data in docket EPA-HQ-OAR-2002-0051. Moreover, 
the analogy with hazardous waste-burning cement kilns breaks down. If a 
cement kiln that fires hazardous waste cannot meet the THC or CO limits 
in the Hazardous Waste Combustor (HWC) NESHAP due to organic materials 
in their feed, they can (and have) simply stopped firing hazardous 
waste. This can either be done permanently, or temporarily anytime the 
kiln operator notes that THC or CO emissions are approaching the 
emission limits. This option is not available to cement kilns that do 
not fire hazardous waste; they cannot stop making cement without 
ceasing business altogether. This would mean that facilities with 
higher levels of organic materials in the raw materials would be forced 
to adopt some type of add-on control to meet the emissions limits. As 
we have previously stated, we believe this would result in the 
imposition of a beyond-the-floor standard without the mandated 
consideration of costs and other impacts. See 70 FR 72335.
    As a result, although we adhere to our approach at proposal that 
the MACT floor for control of non-dioxin organic HAP at existing 
sources is operating under good combustion conditions, we are adopting 
a different means of demonstrating that good fuel combustion conditions 
exist.
    In the final amendments, we are requiring that existing kilns and 
in-line kilns/raw mills must implement GCP designed to minimize THC 
from fuel combustion. GCP include training all operators and 
supervisors to operate and maintain the kiln, calciner, and pollution 
control systems in accordance with good engineering practices. The 
training shall include operating the kiln, calciner, and pollution 
control system in a manner to minimize excess emissions.
    We have also reexamined the proposed MACT floor for new sources. 
There are currently two cement kilns with add-on controls which reduce 
emissions of THC. At one facility, activated carbon is injected into 
the flue gas and collected in the PM control device. The carbon adsorbs 
some of the THC. The collected carbon is then reinjected into the kiln 
in a location that ensures destruction of the collected THC. However, 
the THC emissions from this facility are the highest for any facility 
for which we have data. Therefore, we do not consider this to represent 
the best controlled source. This same facility also has an alternative 
control scheme for THC of a limestone scrubber followed by a 
regenerative thermal oxidizer (RTO). However, these control devices 
have not operated continuously due to significant operation problems 
caused by the site specific constituents in the flue gas. (See e-mail 
from Michael D. Maillard, Michigan Department of Environmental Quality 
in docket EPA-HQ-OAQ-2002-0051.) Because these controls have not been 
demonstrated to have the ability to operate continuously, we cannot 
consider them as the basis for a new source MACT floor (or an emission 
standard, for that matter).
    A second facility also has a limestone scrubber followed by an RTO. 
The scrubber is necessary to prevent fouling, plugging, and corrosion 
of the RTO. In this case the scrubber/RTO operates continuously and 
efficiently. This facility has been tested and showed VOC (essentially 
the same as THC) emission levels of 4 ppmv (at 7 percent oxygen), and 
currently has a permit limit for VOC of approximately 9 ppmv. The RTO 
has a guaranteed destruction efficiency of 98 percent of the combined 
emissions of CO and THC. Based on this information we believe this 
facility is the best controlled source, and that the performance of a 
limestone scrubber followed by an RTO is the basis for new source MACT 
floor for non-dioxin organic HAP, measured as THC. We explain below how 
we assess the long-term performance capabilities of this control device 
considering variable organic levels in raw materials and other process 
variabilities.
    We are retaining the proposed THC emission limit of 20 ppmv 
measured at the main kiln stack as the MACT floor for all new or 
reconstructed kilns and inline raw mill/kilns. An alternative to the 20 
ppmv floor level is that a facility may demonstrate a 98 percent 
reduction in THC emissions from uncontrolled levels--the level of 
emission reduction required by permit for the best performing source in 
the category. We have determined in other rules that a 20 ppmv outlet 
emissions level or 98 percent destruction efficiency represent the long 
term performance of an RTO under the varying conditions typically 
encountered in industrial applications. See Thermal Incinerators and 
Flares in Docket EPA-HQ-OAR-2002-0051. As noted above, the one cement 
facility with an RTO operating full-time has actual and permitted 
emission levels which are below 20 ppmv. However, the performance 
guarantee at this facility is based on the combined emissions of CO and 
THC. Therefore, all new facilities could meet the permitted emission 
levels of the one facility that has an RTO only if they all have the 
same levels of CO in the exhaust gas. We have no data to support that 
all new kilns will have sufficient CO in the exhaust streams to 
guarantee that they can meet the same level of performance as the one 
facility noted above, or, conversely that this one facility would 
continue to meet the same THC levels if CO levels in its exhaust gas 
differed. We thus believe long term performance for THC alone is better 
characterized based on the well-established data documenting 
performance of RTO for THC. Moreover, the percent reduction achievable 
by an RTO is dependent on the inlet concentration of organics. See 
Thermal Incinerators and Flares in Docket EPA-HQ-OAR-2002-0051. Thus, 
we believe that a limit based on the demonstrated performance of RTO 
under a variety of circumstances is the best measure of the long term 
performance of this device under the circumstances likely to be 
encountered by new cement kilns, especially varying levels of organics 
in the feed.
2. Beyond-the-Floor Determinations
    In the December 2005, proposed amendments we considered beyond-the-
floor options for existing sources of substituting raw materials with 
lower organic contents, but we determined this beyond-the-floor option 
was not feasible (70 FR 72340). We also considered a beyond-the-floor 
THC

[[Page 76531]]

standard of 20 ppmv based on the use of the scrubber/RTO control 
system. Based on the available data, we estimate that approximately 75 
percent of existing kilns could meet a 20 ppmv standard without the 
addition of controls. For an existing preheater/precalciner kiln that 
could not meet a 20 ppmv standard without controls, the capital cost 
would be approximately $10.7 million and the total annualized cost 
would be approximately $3.9 million. The cost per ton of THC reduction 
would be in the area of $20,000, assuming an inlet concentration of 
about 63 ppmv. We estimate that approximately 5 percent of the THC is 
actually organic HAP. Therefore, the cost of organic HAP reduction 
would be $398,000 per ton. In addition, the energy use for one large 
kiln to operate an RTO would be approximately 99.7 billion British 
thermal units per year, a very high energy consumption rate. The wet 
scrubber required upstream of the RTO would also result in 40 million 
gallons per year of additional water usage and create 45,500 tpy of 
solid waste (from dewatered scrubber sludge). Based on the costs, 
significant adverse energy impacts, and adverse non-air quality health 
and environmental impacts, we do not believe a beyond-the-floor 
standard is justified.
    We also examined a beyond-the-floor regulatory option based on the 
use of ACI for THC control. The total annual cost for this option would 
be $470,000 to $600,000 for an existing preheater/preclaciner kiln. The 
cost per ton of THC reduction would be in the area of $5,000, assuming 
an inlet concentration of about 63 ppmv. We estimate that approximately 
5 percent of the THC is actually organic HAP. Therefore, the cost of 
organic HAP reduction would be $100,000 per ton. In addition, this 
control option would generate approximately 850 tpy of solid waste. 
Based on the high costs, energy impacts, and adverse non-air quality 
health and environmental impacts, we do not believe a beyond-the-floor 
standard is justified.
    We did not examine a beyond-the-floor regulatory option for new 
sources because there are no controls that would, on average, generate 
a greater THC reduction than a combination of a wet scrubber/RTO. Thus, 
the floor level is also new source MACT.
3. Conclusion
    In sum, we conclude that the standards for THC for all existing 
cement kilns is implementing GCP designed to minimize THC emissions 
from fuel combustion. The compliance date for this standard is one year 
from December 20, 2006. Because all facilities already have some type 
of training program, we believe one year is sufficient to comply with 
this requirement. See section 112(1)(3) (compliance dates for MACT 
standards ``shall provide for compliance as expeditiously as 
practicable'').
    The standard for new sources is to meet a THC standard of either 20 
ppmv or a 98 percent reduction in THC emissions from uncontrolled 
levels. However, as explained above, performance of a back-end control 
device (i.e. the RTO, preceded by an enabling scrubber) was not the 
basis of the proposed new source standard. Information that one kiln 
utilizes an RTO, as well as information regarding the technical 
capabilities of RTO, emerged following the public comment period and 
therefore has not previously been available for public comment. To 
afford opportunity for comment, EPA is itself immediately granting 
reconsideration of the new source standard for THC in a notice 
published elsewhere in today's Federal Register.
    The original Portland Cement NESHAP contains a 50 ppmv THC 
emissions limit for new greenfield kilns, kilns/inline raw mills, and 
raw materials dryers. There are no situations we can identify where a 
50 ppmv limit would be more stringent than a 98 percent reduction 
limit. Since this 50 ppm limit is less stringent than the new source 
standard we are adopting in this rule reflecting performance of an RTO, 
it is obviously not appropriate to retain it. We are thus finding that 
the floor for greenfield new sources (and all other new sources under 
this rule) is 20 ppm/98 percent THC, with one exception. This new 
source limit will, at least for some new facilities, require the 
application of a back end control. For this reason, we do not believe 
this limit should be applied retroactively to sources constructed prior 
to December 2, 2005, the date of proposal for the amendment. See the 
response to comment concerning new sources in section VI for our 
rationale for this decision. So for sources constructed prior to 
December 2, 2005, we are not amending the 50 ppmv THC limit.
    Consistent with section 112(c)(6) we are applying the 20 ppmv/98 
percent reduction limit to both major and area new sources. We are also 
applying the limit to raw materials dryers. We anticipate that all new 
kilns will be preheater/precalciner kilns with an inline raw mill (i.e. 
there will be no separate dryer exhaust). This is the design of the 
kilns that form the basis of new source MACT for THC. However, we see 
no reason that the floor level of control should not apply in the case 
where there is a separate raw material dryer. We note that in the 
original NESHAP, the 50 ppmv standard also applied to raw material 
dryers.
    We are adopting our proposed requirement that compliance for a THC 
standard will be demonstrated using a CEM and a 1-hour averaging 
period. See 70 FR 72340. The previous 50 ppmv standard for new 
greenfield sources was based on a monthly average. We believe a monthly 
average was appropriate for that standard (and are retaining monthly 
averaging for kilns subject to that standard) because the standard's 
basis is selection of raw materials. There can be significant short 
term variations in raw materials, even if a facility can meet the 
standard in the long term. In the case of these final amendments the 
required level of performance is based on an emissions control 
technology. Therefore, we do not anticipate the same type of short term 
variability that existed with the previous 50 ppmv standard.
    Because the final standard is more stringent than the standard EPA 
proposed, the compliance date for sources which commenced construction 
after December 2, 2005, and before promulgation of this final rule is 3 
years from December 20, 2006. See section 112(i)(2). We consider the 
final standard to be more stringent than the proposed standard because 
it is based on the performance of a control device (notwithstanding 
that the numeric limit is the same as proposed), and now controls both 
THC emissions from fuel combustion and THC emissions resulting from the 
organic materials in the kiln feed, and is more likely to result in 
significant costs and changes in operation than the proposed standard.
    For new sources that elect to meet THC emissions limits using ACI, 
we are incorporating the operating and monitoring requirements for ACI 
that are applicable when ACI is used for dioxin control.

D. Evaluation of a Beyond-the-Floor Control Option for Non-Volatile HAP 
Metal Emissions

    In our MACT determination for PM (the surrogate for non-volatile 
HAP metals), we concluded that well-designed and properly operated FF 
or ESP designed to meet the new source performance standards (NSPS) for 
Portland cement plants represent the MACT floor technology for control 
of PM from kilns and in-line kiln/raw mills. Because no technologies 
were identified for existing or new kilns that would consistently 
achieve lower

[[Page 76532]]

emissions than the NSPS, EPA concluded that there was no beyond-the-
floor technology for PM emissions (63 FR 14199, March 24, 1998).
    In National Lime Association v. EPA, the court held that EPA had 
failed to adequately document that substituting natural gas for coal 
was an infeasible control option, and also that EPA had not assessed 
non-air quality health and environmental impacts when considering 
beyond-the-floor standards for HAP metals (233 F. 3d at 634-35). As a 
result, the court remanded the beyond-the-floor determination for HAP 
metals for further consideration by EPA.
    We presented our reexamination of a beyond-the-floor MACT control 
standard for HAP metals in the preamble to the proposed amendments, 
addressing the remand by showing that substitution of fuel or feed 
materials are either technically infeasible or cost prohibitive and 
therefore that a beyond-the-floor standard for HAP metals is not 
reasonable. (See 70 FR 72340-72341). We also indicated that non-air 
health and environmental impacts would be minimal, as would energy use 
implications (id. at 72341). We received no data in the comments on the 
proposed amendments that have altered our previous analysis. Therefore, 
we are not including a beyond-the-floor PM standard in these final 
amendments.

V. Other Rule Changes

    On April 5, 2002, we amended the introductory text of 40 CFR 
63.1353(a) to make it more clear that affected sources under the 
Portland Cement NESHAP were not subject to 40 CFR part 60, subpart F 
(67 FR 16615, April 20, 2002). In making this change, we inadvertently 
deleted paragraphs (a)(1) and (2) of 40 CFR 63.1353. The language in 
these paragraphs is still necessary for determining the applicability 
of 40 CFR part 60, subpart F. We proposed to reinstate these paragraphs 
as originally written in the final rule. We received no comments on 
this issue and are therefore reinstating the two paragraphs as 
proposed.
    In the proposed amendments we requested comment on amending 
language published on April 5, 2002, whose purpose was to clarify that 
crushers were not subject to this NESHAP. The PCA believed that there 
had been misinterpretation of the amended rule text. However, we 
explained in the proposed amendments that we believe the PCA 
interpretation is not reasonable when reading the entire final NESHAP. 
However, we agreed that the rule language as written is conceivably 
open to more than one interpretation. See 70 FR 72341.
    We proposed two resolutions to this issue. They were:
    (1) Changing the wording of 40 CFR 63.1340(c) to make it clear that 
all raw materials storage and handling is covered by the NESHAP, but 
that crushers (regardless of their location) are not.
    (2) Including crushers as an affected source in the Portland Cement 
NESHAP and incorporating the current requirements applicable to 
crushers contained in 40 CFR part 60, subpart OOO (and correspondingly, 
exempting crushers covered by the Portland Cement NESHAP from 40 CFR 
part 60, subpart OOO).
    We received several comments from State and local agencies 
supporting our contention that the intent of the rule language at issue 
was to exclude crushers, and that our interpretation of the rule 
language was correct. We considered simply deleting the (potentially) 
confusing language and adding clarifying language that a crusher 
located after raw materials storage would be covered by this subpart. 
However, we have not been able to identify any facilities where the 
crusher is located after raw materials storage. In addition, we do not 
have data to determine the impacts of adding coverage of this piece of 
equipment to this subpart. For that reason, we are modifying the 
language in Sec.  63.1340(c) to state that crushers are not covered by 
this subpart regardless of their location. There are currently no 
regulations that regulate existing crushers in this application. New 
crushers would potentially be subject to the requirements of 40 CFR 60, 
subpart OOO.

VI. Responses to Major Comments

    This section presents a summary of responses to major comments. A 
summary of the comments received and our responses to those comments 
may be found in Docket ID No. EPA-HQ-OAR-2002-0051.
    Comment: According to several commenters, EPA's proposal did not 
satisfy the mandate issued by the DC Circuit Court of Appeals. On EPA's 
analysis of MACT for mercury, HCl, and THC; EPA's beyond-the-floor 
analysis; and the risk-based exemptions from HCl standards, one 
commenter states they are unlawful, arbitrary, capricious, and 
irrelevant. These commenters state that the court was clear in its 
directive to EPA that the absence of technology-based pollution control 
devices for HCl, mercury, and THC did not excuse EPA from setting 
emission standards for those pollutants.
    Response: Although we disagree with the premise of this comment, 
the comment is moot because we are setting standards for all HAP which 
was addressed by the court's mandate. We agree that the court stated 
the absence of technology-based pollution control devices for HCl, 
mercury, and THC did not excuse EPA from setting emission standards for 
those pollutants. In response to the court's opinion, we have evaluated 
all possibilities of setting standards, including technology based 
control, fuel and raw materials changes, and process modifications. We 
believe this evaluation is what the court intended. See 70 FR 72335.
    Comment: Regarding EPA's rejection of beyond-the-floor standards 
for each HAP, one commenter states that EPA's reasoning is both 
unrelated to the relevant statutory mandate and arbitrary and 
capricious, as well as completely ignoring currently available control 
measures of which EPA is aware and which would result in reductions of 
emissions of mercury, HCl, THC and other HAP.
    Response: Where we have rejected beyond-the-floor standards we have 
evaluated all available control methods that have been demonstrated for 
this source category. We also evaluated control technologies that have 
not been demonstrated, but that we have reason to believe may be 
effective (such as ACI). With one exception, which is banning the use 
of fly ash with elevated mercury contents that result from sorbent 
injection where such a practice would increase mercury emissions, in no 
case did we find that a beyond-the-floor standard was justified 
(``achievable'' in the language of section 112(d)(2)) taking into 
consideration costs, energy, and non-air quality health and 
environmental impacts.
    Comment: According to one commenter, EPA's refusal to set mercury 
standards demonstrates contempt of court. The commenter states that 
EPA's reconsideration of MACT for mercury did not satisfy the court's 
directive to establish emissions standards and not just reconsider the 
issue.
    Citing the CAA's requirements to set emission standards for each 
HAP listed in 112(b) and, as directed in 112, for each category of 
sources for the HAP applying the maximum achievable degree of 
reduction, the commenter states that EPA's decision to not set mercury 
emission standards is unlawful.
    Response: EPA strongly disagrees with the commenter's 
characterization of the proposed standards in the proposed rule. EPA 
issued the proposed rule consistent with the court's

[[Page 76533]]

instructions in the remand. In response to comments received, however, 
EPA has modified the proposal and adopted specific standards for each 
HAP covered by the court's mandate. Thus, this comment is moot, even 
accepting the commenter's premise (which EPA does not), since EPA is 
establishing standards (in the sense the commenter uses the term) for 
each HAP covered by the court's mandate. Moreover, as explained in 
other parts of this preamble, EPA has carefully analyzed many different 
possibilities for setting standards for the HAP covered by the remand, 
examining not only technology-based back end controls but control of 
inputs to cement kilns as well. We believe that our action fully 
satisfies both the letter and spirit of the court's mandate.
    Comment: The commenter above states that EPA's arguments for not 
setting mercury standards are without merit and provide several 
justifications for its view. First the commenter states that EPA's 
arguments for not setting mercury standard are irrelevant because EPA 
has a clear statutory obligation to set mercury standard and any reason 
for not doing so must be invalid.
    Response: This comment is now moot, as just explained.
    Comment: According to the same commenter, EPA's view as to what is 
achievable cannot replace the CAA requirement to set MACT floors 
reflecting what the best performing sources are achieving. The 
commenter states that the CAA mandates a floor reflecting the average 
emission limitation achieved by the best performing 12 percent of the 
existing sources (for which the Administrator has emissions 
information) and not what EPA believes would be achievable. The 
commenter states that the court expressly required EPA to set emission 
standards based on what the best performers are actually achieving and 
not what EPA thinks is achievable.
    Response: As Mossville and earlier cases make clear, because MACT 
standards (based on floors or otherwise) must be met at all times, the 
standards must reflect maximum possible variability (assuming proper 
design and operation of the various control mechanisms). See discussion 
at 70 FR 72335 and 70 FR 59436.
    Comment: The same commenter disagrees with EPA's argument that the 
governing case law (National Lime Ass'n and CKRC) did not involve facts 
where the levels of performance tests are dependent entirely on 
composition of raw materials and fuel and cannot be replicated or 
duplicated. The commenter states that the governing case law addresses 
that exact issue: EPA's decision not to set mercury standards; and 
fourth the commenter claims EPA mistakenly cites the Copper Smelters 
(Sierra Club) and PVC MACT cases (Mossville) as justification for its 
approach. According to the commenter, these cases pertain to beyond-
the-floor standards and do not apply to floor standards, which require 
EPA to set floors at emission levels that the best sources achieved, 
regardless of what EPA thinks is achievable.
    Response: The commenter's reading of Mossville is not correct. The 
case involved a floor standard. See 370 F. 3d at 1240-42. We explained 
at proposal why we believe the discussion of raw materials in Sierra 
Club is also applicable to a floor determination. See 70 FR at 72335 n. 
4.
    Comment: The commenter further states that EPA's argument that its 
emissions data do not reflect performance over time, merely relates to 
the sufficiency of EPA's data. The commenter states that EPA is 
required to develop an approach to setting a floor standard, including 
collecting more emissions data if needed.
    Response: Floor standards are to reflect the performance of sources 
``for which the Administrator has emissions information'' (section 
112(d)(3)), which provision does not create an obligation to gather a 
specified amount of information. Moreover, not only must MACT 
standards, including standards reflecting the MACT floor, reflect 
performance variability but EPA may reasonably estimate what that 
variability can be, and is not limited to stack emissions measured in 
single performance tests as the commenter apparently believes. See 
Mossville, 370 F. 3d at 1242 (setting standard at a level slightly 
higher than the highest data point experienced by a best performing 
source ``reasonably estimates the performance of the best * * * 
performing sources''). Most basically, because MACT standards must be 
met at all times, a standard must reflect performance variability that 
occurs at all times, and this variability is simply not accounted for 
in single stack test results for mercury from a cement kiln.
    Comment: The same commenter disagrees with EPA's position that 
setting the floor at emission levels achieved by the relevant best 
sources would require kilns to install back-end controls, thus 
bypassing beyond-the-floor requirements of achievability, considering 
cost and other statutory factors. Contrary to EPA's position, the 
commenter argues that sources are using low mercury fuel and feed and 
some kilns are using controls that reduce mercury emissions, albeit 
they may not be doing so deliberately to reduce mercury emissions. 
According to the commenter, whether the sources are achieving low 
mercury emissions levels through deliberate measures or coincidentally 
are statutorily irrelevant.
    Response: We disagree with all the points raised in the comment 
above and preceding comments that EPA's arguments for not setting 
mercury standards are without merit. As noted above, we believe we have 
met the court's directive by evaluating all available methods of 
mercury control, including changes to fuels, raw materials, and process 
controls. We do not agree that the court directed us to set standards 
regardless of the facts, nor do we agree that section 112(d)(3) of the 
CAA requires us to set floor standards that cannot be met without 
requiring even the best performing facilities to apply beyond-the-floor 
controls--controls not used by any sources in the source category, even 
those which are ostensibly the best performing (i.e. the lowest 
emitters in individual performance tests).
    The commenter correctly noted that we are required to set standards 
based on facilities for which the administrator has emissions 
information. However, as explained previously in the notice, the 
emissions levels in the data available to the administrator are mainly 
influenced by factors that are beyond the control of the facilities 
tested, and the test results can neither be replicated by the 
individual facilities nor duplicated by other facilities. In addition, 
these are short term data that we believe are not indicative of the 
sources' long term emissions. The commenter states that we should get 
better data. However, they do not indicate how we would be able to 
perform this task given the fact that there are no long term data 
available for mercury emissions from cement kilns: We know of no case 
where any cement facility has applied mercury continuous emission 
monitoring (CEM) technology, or gathered any long term emissions data 
we could use to set a national standard. (We do note, however, that we 
are ourselves granting reconsideration of the new source standard for 
mercury, in part to initiate field testing of cement kilns equipped 
with wet scrubbers.)
    The commenter further states that docket records for Portland 
cement, the hazardous waste standards, and electric utilities 
demonstrate that various pollution controls have the ability to reduce 
mercury emissions. We agree with this comment in part. We believe both 
ACI and wet scrubbers will reduce mercury from cement kilns (and the 
floor for mercury for new sources is

[[Page 76534]]

based on performance of a wet scrubber). We did evaluate these controls 
as beyond-the-floor control options and determined, based on what we 
consider reasonable assumptions of their performance, that requiring 
facilities to apply these controls was not achievable, within the 
meaning of section 112(d)(2) of the CAA, after considering costs, 
energy impacts, and non-air quality health and environmental impacts.
    We also agree that fabric filters and ESPs can reduce mercury 
emissions because there is some mercury retained in the collected CKD. 
As explained earlier, we agree that this forms the basis of a MACT 
floor (and standard), although the degree of mercury reduction is site-
specific based on the rate of recycling per kiln. Because the amount of 
emission reduction associated with the practice is site specific and 
not directly measurable, we are expressing the standard as a work 
practice. We also explained why requiring further reductions based on 
more CKD wastage is not justified as a beyond-the-floor standard based 
on considerations of cost and adverse non-air quality health and 
environmental impacts (increased waste generation and disposal), as 
well as increased energy use.
    In no case did we find that any of the control options discussed by 
the commenter could be considered as the basis for a MACT floor for new 
or existing sources (with the two exceptions just noted) for reasons 
previously discussed.
    We also note that the HWC NESHAP does have mercury limits. However, 
these limits are achieved by controlling the mercury input of the 
hazardous waste feed (through source separation, blending, or other 
means). Therefore, any comparison of the mercury limits for cement 
kilns that burn hazardous waste with cement kilns that do not is 
misplaced.\15\
---------------------------------------------------------------------------

    \15\ Indeed, the entire reason that hazardous waste burning 
cement kilns are a different source category is the impact and 
potential controllability of the hazardous waste inputs. See 64 FR 
at 52871.
---------------------------------------------------------------------------

    The commenter notes that cement kilns are achieving superior 
mercury emissions through a variety of different means, and further 
states that whether they are doing this intentionally is legally 
irrelevant. The comment is correct that the reason for application of a 
particular control technique is irrelevant. National Lime, 233 F. 3d at 
640. But the commenter fails to consider that even in the case where a 
facility applies some type of control scheme, and that scheme happens 
to also reduce a particular HAP, the facility is taking specific 
actions that results in a reduction of the pollutant. For example, a 
facility that installs a thermal oxidizer to reduce total hydrocarbons 
also reduces organic HAP, even though the thermal oxidizer may not have 
been installed for purposes of HAP reduction. However, the facility is 
still taking a specific action that reduces HAP emissions. Also, 
another facility can install a similar control device and expect to 
achieve the same result. Results thus can be duplicated from site to 
site.
    In the case of cement kilns, the ``actions'' being taken that in 
some cases may reduce mercury emissions are the result of site specific 
factors that cannot necessarily be duplicated elsewhere. For example, 
facility A may achieve lower mercury emissions than facility B simply 
because the limestone quarry used by facility A has a lower mercury 
content (at least on the day of the respective performance tests). 
Facility A is not achieving lower mercury emissions deliberately, but 
it is still achieving a lower level. However, because facility B does 
not have access to facility A's quarry, it would have to use some other 
control technique to match facility A's mercury emissions. The 
commenter never disputes that requiring facility B (and quite possibly 
A) to match the performance will require installation of a control 
device not used in the industry. As explained at proposal and earlier 
in the preamble, this amounts to an impermissible de facto beyond-the-
floor standard.
    The commenter also states that the best performing kilns are 
achieving lower mercury emission using a variety of methods, but does 
not offer any data or analysis as to what these methods are, or how 
other facilities could duplicate the performance of the lower emitting 
facilities without adding some type of back end controls. In addition, 
due to the wide variation in emissions level due to variations in raw 
materials, we have no data to show conclusively that even if back end 
controls were applied that kilns with higher mercury emissions due to 
higher mercury contents in their limestone could achieve the same 
emissions levels as facilities with naturally occurring low mercury 
limestone used in the (one-time, snapshot) performance test.
    Comment: Regarding EPA's rejection of a beyond-the-floor mercury 
standard on the basis of low levels of mercury emissions and high costs 
of reducing emissions, one commenter states that the CAA requires that 
EPA's standards must reflect the ``maximum degree of reduction that is 
achievable'' considering the ``cost of achieving such emission 
reduction'' and other enumerated statutory factors. According to the 
commenter, the only relevant factors regarding the cost measures are: 
(1) Whether it is too costly to be ``achievable''; and (2) whether it 
would yield additional reductions, i.e., without the measure, the 
standard would not reflect the ``maximum'' achievable degree of 
reduction. The commenter states that EPA does not claim that the use of 
ACI would not be achievable, only that ACI is not ``justified.'' This 
position, according to the commenter, contravenes the CAA and exceeds 
EPA's authority and would allow EPA to avoid properly determining the 
maximum degree of reduction achievable considering cost and the other 
enumerated factors.
    Response: We disagree with the commenter's interpretation.
    The statute requires that EPA consider ``the cost of achieving such 
emission reduction'' (section 112 (d)(2)) in determining the maximum 
emission reduction achievable. This language does not mandate a 
specific method of taking costs into account, as the commenter would 
have it, but rather leaves EPA with significant discretion as to how 
costs are to be considered. See Husqvarna AB v. EPA, 254 F. 3d 195, 200 
(D.C. Cir. 2001). In that case, the court interpreted the requirement 
in section 213 (a) (3) of the CAA (which mirrors the language in 
section 112(d)(2))that nonroad engines ``achieve the greatest degree of 
emission reduction achievable through the application of [available] 
technology * * * giving appropriate consideration to the cost of 
applying such technology'', and held that this language ``does not 
mandate a specific method of cost analysis''. The court therefore 
``f[ound] reasonable EPA's choice to consider costs on the per ton of 
emissions removed basis''.
    Moreover, where Congress intended that economic achievability be 
the means of assessing the reasonableness of costs of technology-based 
environmental standards, it says so explicitly. See Clean Water Act 
section 301 (b) (2) (A) (direct dischargers of toxic pollutants to 
navigable waters must meet standards reflecting ``best available 
technology economically achievable'' (emphasis added). There is no such 
explicit directive in section 112 (d)(2). EPA accordingly does not 
accept the commenter's interpretation.
    Comment: Several comments support EPA's decision not to develop 
either an existing or new source floor for mercury. The commenters 
state that an achievable floor cannot be developed

[[Page 76535]]

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

[[Page 76536]]

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

[[Page 76537]]

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

[[Page 76538]]

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

[[Page 76539]]

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

[[Page 76540]]

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

[[Page 76541]]

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

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

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

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

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

[[Page 76542]]

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

[[Page 76543]]

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

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

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

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

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

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

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

[[Page 76544]]

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

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

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

[[Page 76545]]

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

VII. Summary of Environmental, Energy, and Economic Impacts

A. What facilities are affected by the final amendments?

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

B. What are the air quality impacts?

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

[[Page 76546]]

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

C. What are the water quality impacts?

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

D. What are the solid waste impacts?

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

E. What are the energy impacts?

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

F. What are the cost impacts?

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

G. What are the economic impacts?

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

[[Page 76547]]

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

VIII. Statutory and Executive Order Reviews

A. Executive Order 12866, Regulatory Planning and Review

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

B. Paperwork Reduction Act

    The information collection requirements in this final rule have 
been submitted for approval to the OMB under the Paperwork Reduction 
Act, 44 U.S.C. 3501 et seq. The information collection requirements are 
not enforceable until OMB approves them.
    The information requirements are based on notification, 
recordkeeping, and reporting requirements in the NESHAP General 
Provisions (40 CFR part 63, subpart A), which are mandatory for all 
operators subject to national emission standards. These recordkeeping 
and reporting requirements are specifically authorized by section 114 
of the CAA (42 U.S.C. 7414). All information submitted to EPA pursuant 
to the recordkeeping and reporting requirements for which a claim of 
confidentiality is made is safeguarded according to Agency policies set 
forth in 40 CFR part 2, subpart B.
    These requirements include records of CKD removal from the kiln 
system at all existing and new sources, and requirements for new kilns 
constructed after December 2, 2005, to install and test a continuous 
monitor to measure THC. We expect these additional requirements to 
affect 94 facilities over the first 3 years. The estimated annual 
average burden is outlined below.

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

    Burden means the total time, effort, or financial resources 
expended by persons to generate, maintain, retain, or disclose or 
provide information to or for a Federal agency. This includes the time 
needed to review instructions; develop, acquire, install, and utilize 
technology and systems for the purposes of collecting, validating, and 
verifying information, processing and maintaining information, and 
disclosing and providing information; adjust the existing ways to 
comply with any previously applicable instructions and requirements; 
train personnel to be able to respond to a collection of information; 
search data sources; complete and review the collection of information; 
and transmit or otherwise disclose the information.
    An agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information unless it displays a 
currently valid OMB control number. The OMB control numbers for EPA's 
regulations in 40 CFR are listed in 40 CFR part 9. When this 
information collection request is approved by OMB, the Agency will 
publish a technical amendment to 40 CFR part 9 in the Federal Register 
to display the OMB control number for the approved information 
collection requirements contained in this final rule.

C. Regulatory Flexibility Act

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

[[Page 76548]]

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

D. Unfunded Mandates Reform Act

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

E. Executive Order 13132, Federalism

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

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

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

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

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

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

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

[[Page 76549]]

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

I. National Technology Transfer and Advancement Act

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

J. Congressional Review Act

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

List of Subjects in 40 CFR Part 63

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

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

0
For the reasons stated in the preamble, title 40, chapter I, part 63 of 
the Code of Federal Regulations is amended as follows:

PART 63--[Amended]

0
1. The authority citation for part 63 continues to read as follows:

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

Subpart LLL--[Amended]

0
2. Sec.  63.1342 is revised to read as follows:


Sec.  63.1342  Standards: General.

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

0
3. Section 63.1343 is revised to read as follows:


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

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

[[Page 76550]]

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

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


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

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

[[Page 76551]]

Sec.  63.1343 that employs carbon injection as an emission control 
technique may substitute, at any time, a different brand or type of 
activated carbon provided that the replacement has equivalent or 
improved properties compared to the activated carbon specified in the 
site-specific performance test plan and used in the performance test. 
The owner or operator must maintain documentation that the substitute 
activated carbon will provide the same or better level of control as 
the original activated carbon.
    (f) Existing kilns and in-line kilns/raw mills must implement good 
combustion practices (GCP) designed to minimize THC from fuel 
combustion. GCP include training all operators and supervisors to 
operate and maintain the kiln and calciner, and the pollution control 
systems in accordance with good engineering practices. The training 
shall include methods for minimizing excess emissions.
    (g) No kiln and in-line kiln/raw mill may use as a raw material or 
fuel any fly ash where the mercury content of the fly ash has been 
increased through the use of activated carbon, or any other sorbent 
unless the facility can demonstrate that the use of that fly ash will 
not result in an increase in mercury emissions over baseline emissions 
(i.e. emissions not using the fly ash). The facility has the burden of 
proving there has been no emissions increase over baseline.
    (h) All kilns and in-line kilns/raw mills must remove (i.e. not 
recycle to the kiln) from the kiln system sufficient cement kiln dust 
to maintain the desired product quality.
    (i) New and reconstructed kilns and in-line kilns/raw mills must 
not exceed the average hourly CKD recycle rate measured during mercury 
performance testing. Any exceedance of this average hourly rate is 
considered a violation of the standard.
0
5. Section 63.1346 is revised to read as follows:


Sec.  63.1346  Standards for new or reconstructed raw material dryers.

    (a) New or reconstructed raw material dryers located at facilities 
that are major sources can not discharge to the atmosphere any gases 
which:
    (1) Exhibit opacity greater than ten percent, or
    (2) Contain THC in excess of 20 ppmv, on a dry basis as propane 
corrected to 7 percent oxygen if the source commenced construction 
after December 2, 2005. As an alternative to the 20 ppmv standard, you 
may demonstrate a 98 percent reduction in THC emissions from the exit 
of the raw materials dryer to discharge to the atmosphere. If the 
source is a greenfield dryer constructed on or prior to December 2, 
2005, then the THC limit is 50 ppmv, on a dry basis corrected to 7 
percent oxygen.
    (b) New or reconstructed raw materials dryers located at a facility 
that is an area source cannot discharge to the atmosphere any gases 
which contain THC in excess of 20 ppmv, on a dry basis as propane 
corrected to 7 percent oxygen if the source commenced construction 
after December 2, 2005. As an alternative to the 20 ppmv standard, you 
may demonstrate a 98 percent reduction in THC emissions from the exit 
of the raw materials dryer to discharge to the atmosphere. If the 
source is a greenfield dryer constructed on or prior to December 2, 
2005, then the THC limit is 50 ppmv, on a dry basis corrected to 7 
percent oxygen.

0
6. Section 63.1349 is amended as follows:
0
a. By revising paragraph (b)(4);
0
b. By adding paragraph (b)(5);
0
c. By removing paragraph (f).


Sec.  63.1349  Performance Testing Requirements.

* * * * *
    (b) * * *
    (4)(i) The owner or operator of an affected source subject to 
limitations on emissions of THC shall demonstrate initial compliance 
with the THC limit by operating a continuous emission monitor in 
accordance with Performance Specification 8A of appendix B to part 60 
of this chapter. The duration of the performance test shall be three 
hours, and the average THC concentration (as calculated from the one-
minute averages) during the three-hour performance test shall be 
calculated. The owner or operator of an in-line kiln/raw mill shall 
demonstrate initial compliance by conducting separate performance tests 
while the raw mill of the in-line kiln/raw mill is under normal 
operating conditions and while the raw mill of the in-line kiln/raw 
mill is not operating.
    (ii) The owner or operator of an affected source subject to 
limitations on emissions of THC who elects to demonstrate compliance 
with the alternative THC emission limit of 98 percent weight reduction 
must demonstrate compliance by also operating a continuous emission 
monitor in accordance with Performance Specification 8A of appendix B 
to part 60 at the inlet to the THC control device of the kiln, inline 
kiln raw mill, or raw materials dryer in the same manner as prescribed 
in paragraph (i) above. Alternately, you may elect to demonstrate a 98 
weight percent reduction in THC across the control device using the 
performance test requirements in 40 CFR part 63, subpart SS.
    (5) The owner or operator of a kiln or in-line kiln/raw mill 
subject to the 41 [mu]g/dscm mercury standard shall demonstrate 
compliance using EPA Method 29 of 40 CFR part 60. ASTM D6784-02, 
Standard Test Method for Elemental, Oxidized, Particle-Bound and Total 
Mercury Gas Generated from Coal-Fired Stationary Sources (Ontario Hydro 
Method), is an acceptable alternative to EPA Method 29 (portion for 
mercury only). If the kiln has an in-line raw mill, you must 
demonstrate compliance with both raw mill off and raw mill on. You must 
record the hourly recycle rate of CKD during both test conditions and 
calculate an average hourly rate for the three test runs for each test 
condition.
* * * * *

0
7. Section 63.1350 is amended as follows:
0
a. Revising paragraphs (g), (h) and (n); and
0
b. Adding paragraphs (o) and (p).


Sec.  63.1350  Monitoring requirements.

* * * * *
    (g) The owner or operator of an affected source subject to an 
emissions limitation on D/F, THC or mercury emissions that employs 
carbon injection as an emission control technique shall comply with the 
monitoring requirements of paragraphs (f)(1) through (f)(6) and (g)(1) 
through (g)(6) of this section to demonstrate continuous compliance 
with the D/F, THC or mercury emissions standard.
    (1) Install, operate, calibrate and maintain a continuous monitor 
to record the rate of activated carbon injection. The accuracy of the 
rate measurement device must be 1 percent of the rate being 
measured.
    (2) Verify the calibration of the device at least once every three 
months.
    (3) The three-hour rolling average activated carbon injection rate 
shall be calculated as the average of 180 successive one-minute average 
activated carbon injection rates.
    (4) Periods of time when one-minute averages are not available 
shall be ignored when calculating three-hour rolling averages. When 
one-minute averages become available, the first one-minute average is 
added to the previous 179 values to calculate the three-hour rolling 
average.
    (5) When the operating status of the raw mill of the in-line kiln/
raw mill is changed from off to on, or from on to off, the calculation 
of the three-hour

[[Page 76552]]

rolling average activated carbon injection rate must begin anew, 
without considering previous recordings.
    (6) The owner or operator must install, operate, calibrate and 
maintain a continuous monitor to record the activated carbon injection 
system carrier gas parameter (either the carrier gas flow rate or the 
carrier gas pressure drop) established during the mercury, THC or D/F 
performance test in accordance with paragraphs (g)(6)(i) through 
(g)(6)(iii) of this section.
    (i) The owner or operator shall install, calibrate, operate and 
maintain a device to continuously monitor and record the parameter 
value.
    (ii) The owner or operator must calculate and record three-hour 
rolling averages of the parameter value.
    (iii) Periods of time when one-minute averages are not available 
shall be ignored when calculating three-hour rolling averages. When 
one-minute averages become available, the first one-minute average 
shall be added to the previous 179 values to calculate the three-hour 
rolling average.
    (h) The owner or operator of an affected source subject to a 
limitation on THC emissions under this subpart shall comply with the 
monitoring requirements of paragraphs (h)(1) through (h)(3) of this 
section to demonstrate continuous compliance with the THC emission 
standard:
    (1) The owner or operator shall install, operate and maintain a THC 
continuous emission monitoring system in accordance with Performance 
Specification 8A, of appendix B to part 60 of this chapter and comply 
with all of the requirements for continuous monitoring systems found in 
the general provisions, subpart A of this part.
    (2) The owner or operator is not required to calculate hourly 
rolling averages in accordance with section 4.9 of Performance 
Specification 8A if they are only complying with the 50 ppmv THC 
emissions limit.
    (3) For facilities complying with the 50 ppmv THC emissions limit, 
any thirty-day block average THC concentration in any gas discharged 
from a greenfield raw material dryer, the main exhaust of a greenfield 
kiln, or the main exhaust of a greenfield in-line kiln/raw mill, 
exceeding 50 ppmvd, reported as propane, corrected to seven percent 
oxygen, is a violation of the standard.
    (4) For new facilities complying with the 20 ppmv THC emissions 
limit, any hourly average THC concentration in any gas discharged from 
a raw material dryer, the main exhaust of a greenfield kiln, or the 
main exhaust of a kiln or in-line kiln/raw mill, exceeding 20 ppmvd, 
reported as propane, corrected to seven percent oxygen, is a violation 
of the standard.
* * * * *
    (n) Any kiln or kiln/in-line raw mill using a control device (other 
then ACI) to comply with a mercury emissions limit or equipment 
standard will monitor the control device parameters as specified in 40 
CFR part 63 subpart SS.
    (o) For kilns and in-line kilns/raw mills complying with the 
requirements in Section 63.1344(g), each owner or operator must obtain 
a certification from the supplier for each shipment of fly ash received 
to demonstrate that the fly ash was not derived from a source in which 
the use of activated carbon, or any other sorbent, is used as a method 
of mercury emissions control. The certification shall include the name 
of the supplier and a signed statement from the supplier confirming 
that the fly ash was not derived from a source in which the use of 
activated carbon, or any other sorbent, is used as a method of emission 
control.
    (p) If the facility opts to use a fly ash derived from a source in 
which the use of activated carbon, or any other sorbent, is used as a 
method of mercury emissions control and demonstrate that the use of 
this fly ash does not increase mercury emissions, they must obtain 
daily fly ash samples, composites monthly, and analyze the samples for 
mercury.

0
8. Section 63.1351 is revised to read as follows:


Sec.  63.1351  Compliance dates.

    (a) Except as noted in paragraph (c) below, the compliance date for 
an owner or operator of an existing affected source subject to the 
provisions of this subpart is June 14, 2002.
    (b) Except as noted in paragraph (d) below, the compliance date for 
an owner or operator of an affected source subject to the provisions of 
this subpart that commences new construction or reconstruction after 
March 24, 1998, is June 14, 1999, or upon startup of operations, 
whichever is later.
    (c) The compliance date for an existing source to meet the 
requirements of GCP for THC is December 20, 2007.
    (d) The compliance date for a new source which commenced 
construction after December 2, 2005, and before December 20, 2006 to 
meet the THC emission limit of 20 ppmv/98 percent reduction or the 
mercury standard of 41 [mu]g/dscm or a site-specific standard based on 
application of a wet scrubber will be December 21, 2009.

0
9. Section 63.1355 is amended by adding paragraphs (d), (e) and (f) to 
read as follows:


Sec.  63.1355  Recordkeeping requirements.

* * * * *
    (d) You must keep annual records of the amount of CKD which is 
removed from the kiln system and either disposed of as solid waste or 
otherwise recycled for a beneficial use outside of the kiln system.
    (e) You must keep records of the amount of CKD recycled on an 
hourly basis.
    (f) You must keep records of all fly ash supplier certifications as 
required by Sec.  63.1350(o).

0
10. Section 63.1356 is amended by revising paragraph (a) to read as 
follows:


Sec.  63.1356  Exemption from new source performance standards.

    (a) Except as provided in paragraphs (a)(1) and (2) of this 
section, any affected source subject to the provisions of this subpart 
is exempt from any otherwise applicable new source performance standard 
contained in subpart F or subpart OOO of part 60 of this chapter.
    (1) Kilns and in-line kiln/raw mills, as applicable, under 40 CFR 
60.60(b), located at area sources are subject to PM and opacity limits 
and associated reporting and recordkeeping, under 40 CFR part 60, 
subpart F.
    (2) Greenfield raw material dryers, as applicable under 40 CFR 
60.60(b), located at area sources, are subject to opacity limits and 
associated reporting and recordkeeping under 40 CFR part 60, subpart F.
* * * * *
 [FR Doc. E6-21405 Filed 12-19-06; 8:45 am]

BILLING CODE 6560-50-P
