  SEQ CHAPTER \h \r 1 	6560-50-P

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2002-0051; FRL-    ]

RIN 2060-AJ78

National Emission Standards for Hazardous Air Pollutants

From the Portland Cement Manufacturing Industry

AGENCY:  Environmental Protection Agency (EPA).  

ACTION:  Final Rule

SUMMARY:  On June 14, 1999, under the authority of section 112 of the
Clean Air Act (CAA), the 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). 


We published a proposed response to the court’s remand on December 2,
2005.  We received over 1700 comments on our 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 [INSERT DATE OF PUBLICATION IN
THE FEDERAL REGISTER]

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
  HYPERLINK "http://www.regulations.gov"  www.regulations.gov  web site.
Although listed in the index, some information is not publicly
available, e.g., 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   HYPERLINK "http://www.regulations.gov" 
www.regulations.gov  or in hard copy at the 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 the 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

Category	NAICS1	Examples of regulated entities

Industry	32731	Owners or operators of portland cement manufacturing
plants.

State	32731	Owners or operators of portland cement manufacturing plants.

Tribal associations	32731	Owners or operators of portland cement
manufacturing plants.

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
District of Columbia Circuit by [INSERT DATE 60 DAYS FROM DATE OF
PUBLICATION OF THIS FINAL RULE IN THE FEDERAL REGISTER].  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

  SEQ CHAPTER \h \r 1 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

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 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)).  The 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 nonair 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).	

	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 final rule established
MACT-based emission limitations for particulate matter (as a surrogate
for non-volatile HAP metals), dioxins/furans, and for greenfield 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.    SEQ CHAPTER \h \r 1  In response to the
mandate of the District of Columbia 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
addressed the lack of a mercury emission limitation in the proposed
amendments.  Today’s 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 today’s 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.

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.    SEQ CHAPTER \h \r 1 	

	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.

	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 nonair 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

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).  

	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 beyond-the-floor options for
mercury control). We obtained additional mercury emissions test data
during and after the two comment periods for 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.

Control of Mercury in Primary Raw Materials and Fossil Fuels

         i.  Mercury Emission Levels Reflecting Raw Material and Fossil
Fuel Contributions are Inherently Site-Specific 

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.  Small amounts of mercury also are found in other
raw material inputs to the process.  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).  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). 

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 the facility was one
of the lower emitting facilities in the source category demonstrating
emissions of 7.8 µg/dscm (all test values are corrected to seven
percent oxygen).  During a second test eight years later (reflecting raw
materials from the same quarry) mercury emissions with the raw mill on
were 60 µg/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.

We also obtained data from a facility that was retested for mercury in
July 2005 within three 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.  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.  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.   

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 that the facility to incorporate additional raw material additives
containing mercury to compensate for the loss of the coal ash.        

We thus 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). 

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 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).  For new sources, the lowest permit limit is a measure of
performance of the “best controlled 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.  We could 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 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 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 nonair
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 Clean
Air Act’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
and nonair 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).  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 nonair 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 qualified, 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.  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.     

Another option we considered was using long term data to set a floor. 
However, to our knowledge, since 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 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.  These kilns replace a natural material, shale,
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 the Act, and that for cement kilns currently using fly ash,
the current use would be considered the MACT floor.  Our reasoning is as
follows.

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 the 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 fifty
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 ppmv to 3 ppmv. 
Because fly ash can reduce kiln fuel consumption, it reduces emissions
of SO2, NOx, and carbon monoxide.  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 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 should also be noted that there are at least two new facilities whose
permits specifically required use of fly ash as their alumina source, so
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 based on control based on substitution of either raw
materials or other fly ash 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.  This results in an apparent
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 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.

Mercury is also adsorbed on the CKD collected in the particulate control
device, typically a fabric filter or an 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 (as it happens) for control of SO2.  Commenters noted that
based on experience with utility boilers, as well as on general
engineering principles, there is reason to expect that the scrubbers
installed on cement kilns also remove 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 µg/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 mercury for reason
discusssed below, though we cannot not say with certainty how much.

First, there are an insufficient number of wet-scubber 

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.  

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.  

There is a reasonable basis for finding that wet scrubbers remove
mercury from cement kiln emissions.  Wet scrubbers are known to remove
mercury in most utility boiler applications, removal rates in that
industry being documented from between 0 to 72 per cent of incoming
mercury. See Control of Mercury Emissions from Coal-Fired Electric
Utility Boilers:  Interim Report Including Errata available at
www.epa.gov/nrmrl/pubs/600r01109/600r01109.htm.  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.  Oxidized
mercury is the type of mercury known to be removed by wet scrubbers.  
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 indicate that mercury removal
is occurring.  

We estimated the performance of the best performing scrubber, and hence
the new source MACT floor, as follows.  We are setting a new source
mercury emissions limit of 41 µg/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 discussed, the wet
scrubber equipped kilns represent the best performing sources,
regardless of their actual outlet emissions levels.  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 the standard deviation of the
data multiplied by 2.326 to produce the 99th confidence interval.  We
looked to all of the data, rather than data from a single kiln, because
there are too few data points 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 µg/dscm that
must be met continuously (raw mill on and raw mill off).  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 ug/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 µg/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 fail to definitively answer the critical
question of whether wet scrubbers are removing mercury,and to what
extent.  We are taking immediate steps to address this issue and augment
the data base.  In an action published elsewhere in today’s Federal
Register, we are ourselves 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 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 [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER].  

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 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 72333-34.

	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 ton per year
(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 tons per year based on assumed CKD mercury concentrations
of 0.33 and 1.53 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 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 elements 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 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 tons
per year of solid waste.  There would also be adverse environmental air
and nonair environmental impacts associated with the additional raw
materials that would have to be mined.  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 nonair 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,
but it could.  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 of 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 form Electric Utilities Using Enhanced Sorbents for Mercury
Control in the docket).  Testing to date has shown increases of a factor
of 2 to 10, and in one case of a very low mercury fly ash the increase
was a factor of 70.  

Data from 16 cement facilities currently using fly ash not reflecting
sorbed mercury showed mercury concentrations in the fly ash ranged 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 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 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. 
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).  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 activated carbon injection.

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 beleiving that the wet scrubbers remove
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) from performance of wet
scrubbers in the utility boiler category and represents the greatest
degree of removal one would 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.

Table 1. Packed Bed Scrubber – Costs and Emission Reductions

Clinker Production

(tpy)	Total Annualized Cost

($/yr)	Emissions Reduction



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, not at all cost effective. 
In addition, a wet scrubber for a large kiln will generate approximately
50,000 tons per year of solid waste and require approximately 980,000
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 practice 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 µg/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 NHW
cement kilns tested had mercury concentrations well below 65 µg/dscm. 
Therefore, the long term performance of ACI on mercury emission 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 tons per year of solid waste for a new or existing
large kiln.

	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 nonair environmental impacts. 
For new sources we rejected the option based on the performance of ACI
combined with a wet scrubber due to the significant cost per ton of
mercury removed, increased energy use and the nonair environmental
impacts.  For new and existing sources we 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
also 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
reconsider our decision that 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 µg/dscm or a site-specific
limit based on performance of a properly designed and operated wet
scrubber.  

For purposes of the new source standard, a new source is any source
constructed or reconstructed after December 2, 2005, the date of
proposal for the amendments.  See the response to comment concerning new
sources in section VI for our rationale for use of the December 2005
proposal date.     

	We are also using the discretion granted under section 112(i)(1) to
grant new sources three years from [INSERT THE DATE OF PUBLICATION OF
THE FINAL AMENDMENTS IN THE FEDERAL REGISTER] or startup, whichever is
later, to comply with the new source standards.  We have this discretion
whenever we promulgate a final standard that is more stringent than the
proposed standard, which is the case here.                              
                             

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 one other operation
factor 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 turn recycling back on 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.

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 sulfur dioxide (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.  Based on the presence of continuously operated alkaline
scrubbers at portland cement plants, we proposed that the performance of
continuously operated alkaline scrubbers represents MACT for new
sources, and set proposed emissions levels of 15 ppmv at the control
device outlet, or a 90 percent HCl emissions reduction measured across
the scrubber.

	 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 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 did not
consider the costs and nonair environmental impacts 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
that do not pose adverse environmental impacts.  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 regulating HCl emissions from cement kilns.   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 current HCl levels emitted from cement kilns would
provide “an ample margin of safety”, in protecting human health and
the environment.  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 ample margin of safety 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 some categories emitting threshold
pollutants. 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 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 form
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 hydrochloric acid (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 and short term concentration threshold.  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
(µg/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.  To
evaluate potential short term health impacts the CalEPA REL of 2,100
µg/m3 was used as the AEGL.  

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 to
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.  Hydrogen chloride 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 both chronic (annual average) and
acute (one hour) concentrations for comparison to the relevant health
reference values or threshold levels.  Acute and chronic exposures were
compared to the CalEPA REL value of 2,100 µg/m3 for one-hour exposures
and the RfC of 20 µg/m3 for long-term continuous exposure,
respectively.  

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 do not necessarily
imply that adverse effects will occur, but that the potential for risk
of such effects increases as HQ values exceed 1. 

At this point, it should be noted that the potential for effects depends
on an individual’s total exposure to that chemical.  As a result,
exposure from all sources, not just the one in question, must be
evaluated.  To take background concentrations of HCl into consideration,
data were obtained from the EPA AirData data base
(http://www.epa.gov/air/data/index.html) for data collected in all
states for any year between 1957 and 2006.

Based on these data, a conservative estimate of the average background
concentration of HCl was assumed to be 5.774 μg/m3, the highest average
concentration at any location, which was used to evaluate long term
background conditions.  This value would equate to a HQ of 0.29.  The
maximum concentration detected, 23.7 μg/m3, was used as an estimate of
the maximum short term background concentration.  This would equate to
an  short term hazard quotient (HQst) of 0.01.    

For the PCA assessment, if the HQ was found to be less than 0.71 (a
total of 1 including background) 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 0.71, analysis proceeded to
subsequent tiers.  For the short term analysis, if the HQst was 0.99 or
less (a total of 1 including background), the analysis concluded with
that tier.

The tier 1 modeling resulted in an HQ above 0.71 for all facilities and
an HQst above 0.99 for most facilities.  Therefore, a Tier 2 analysis
was required.  In the Tier 2 analysis, all facilities except for eight
showed an HQ below 0.71, an HQst below 0.99.

For the eight facilities with an HQ above 0.71, 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 eight
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 or HQst of 1.0 considering
background concentrations.  Therefore, we believe that the predicted
exposures from these facilities should provide an ample margin of safety
to ensure that total exposures for nearby residents should not exceed
the short-term or long-term health based threshold levels or health
reference values, even when considering the possible contributions of
other sources of HCl.  

The standards for emissions must also protect against significant and
widespread adverse environmental effects to wildlife, aquatic life, and
other natural resources.  The PCA did not conduct a formal ecological
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 µg/m3 can be expected to result in discernible effects, depending
on the plant species.  Plants respond differently to HCl as an anhydrous
gas than to HCl aerosols.  Relative humidity is important in plant
response; there appears to be a threshold of relative humidity above
which plants will incur twice as much damage at a given dose.  Effects
include leaf injury and decrease in chlorophyll levels in various
species given acute, 20minute exposures of 6,500 to 27,000 µg/ m3.  A
field study reports different sensitivity to damage of foliage in 50
species growing in the vicinity of an anhydrous aluminum chloride
manufacturer.  American elm, bur oak, eastern white pine, basswood, red
ash and several bean species were observed to be most sensitive. 
Concentrations of HCl in the air were not reported.  Chloride ion in
whole leaves was 0.2 to 0.5 percent of dry weight; sensitive species
showed damage at the lower value, but tolerant species displayed no
injury at the higher value.  Injury declined with distance from the
source with no effects observed beyond 300 meters.  The maximum modeled
long-term HCl concentration (less than 100 µg/m3) is well below the 600
µg/m3 chronic threshold, and the maximum short-term HCl concentration
(less than 1600 µg/m3) is well below the 6,500 µg/m3 acute exposure
threshold.  Therefore, no adverse exposure effects are anticipated.  

Prevailing meteorology strongly determines the fate of HCl in the
atmosphere.  However, HCl is not considered 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.  In addition, HCl will react
with hydroxy ions to yield water plus chloride ions.  However, the
concentration of hydroxy ions in the troposphere is low, so HCl may have
a relatively long residence time in areas of low humidity.  No studies
are reported of HCl levels in ponds or other small water bodies or soils
near major sources of HCl emissions.  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.  Deleterious effects of HCl on ponds and soils, where such effects
might be found near a major source emitting to the atmosphere, likely
will be local rather than widespread, as observed in plant foliage.  

Effects of HCl on tissues are generally restricted to those immediately
affected and are essentially acidic effects.  The rapid solubility of
HCl in aqueous media releases hydronium ions, which can be corrosive to
tissue when above a threshold concentration.  The chloride ions may be
concentrated in some plant tissues, but may be distributed throughout
the organism, as most organisms have chloride ions in their fluids. 
Leaves or other tissues exposed to HCl may show some concentration above
that of their immediate environment; that is, some degree of
bioconcentration can occur.  However, long-term storage in specific
organs and biomagnification of concentrations of HCl in trophic levels
of a food chain would not be expected.  Thus, the chemical nature of HCl
results in deleterious effects, that when present, are local rather than
widespread.  

In conclusion, acute and chronic exposures to expected HCl
concentrations around cement kilns are not expected to result in adverse
toxicity effects.  Hydrogen chloride 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

	Total hydrocarbons (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.  The 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 oxides of nitrogen (NOx), and 1.2 times as much
carbon dioxide (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 transfer the standards for cement
kilns that fire hazardous waste (40 CFR 63.1220(a)(5)) in the Portland
Cement NESHAP.  Our rationale for transferring these standards was that
the THC and CO standards guarantee that the kiln will operate under good
combustion conditions and will minimize formation (and hence, emissions)
of non-dioxin organic HAP.  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 good combustion practices 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 tranbsfer of the
standards for cement kilns firing hazardous waste seemed appropriate. 

We continue to believe that good 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 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 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 good combustion practices, 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 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 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 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 combustion conditions exist.  

In the final amendments, we are requiring that existing kilns and
in-line kilns/raw mills must implement good combustion practices (GCP)
designed to minimize THC from fuel combustion.  Good combustion
practices 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 both good
operating practices as well as operating the kiln, claciner, 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 insures 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 email
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.  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 a 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
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 that a 20 ppmv outlet emissions level and 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.  The percent
reduction acheivable 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 RTOs 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.

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 limit is less stringent than the floor based on 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) is 20 ppm/98% 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 new sources constructed prior to December 2,
2006, the date of proposal for the amendments.  See the response to
comment concerning new sources in section VI for our rationale for this
decision.  So for new sources constructed prior to December 2, 2006 we
are retaining the 50 ppmv THC limit.   

2.  Beyond-the-floor Determinations   

	We previously 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 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 Btu/yr.  Based on the costs and energy
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

	The limit for new sources adopted here also applies to both area and
major new sources.  The application of this limit to area sources is a
result of the requirements of section 112(c)(6) which states that MACT
controls should be applied to HAP listed in section 112 (c)(6). 
Therefore, polycyclic organic matter (for which THC is a surrogate) for
both area and major sources should be subject to MACT standards.  (See
63 FR 14193 – 14194).  For this reason, we are applying the 20 ppmv/98
percent reduction limit to both major and area 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 retaining 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.  

	We are also using the discretion granted under section 112(i)(1) to
grant new sources three years from [INSERT THE DATE OF PUBLICATRION OF
THE FINAL AMENDMENTS IN THE FEDERAL REGISTER] or startup, whichever is
later, to comply with the new source standards.  We have this discretion
whenever we promulgate a final standard that is more stringent than the
proposed standard, which is the case here.                              
                             

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 fabric
filter (FF) or electrostatic precipitator (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 emissions than the NSPS,
EPA concluded that there was no beyond-the-floor technology for PM
emissions (63 FR 14199, March 24, 1998).

	  SEQ CHAPTER \h \r 1 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 nonair 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 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 Portland Cement Association (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 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
paragraph 63.1340(c) to state that crushers are not covered by this
subpart regardless of their location.  These 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 all 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 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 were
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 HAPs.

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 the standard was justified (“achievable” in
the language of section 112 (d)(2)) taking into consideration costs,
energy, and nonair 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:  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.

Comment:  The commenter states that EPA’s arguments for not setting
mercury standards are without merit and provides 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.  

Second, according to the 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.  

Third, the 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 also believe the discussion of raw materials in
Sierra Club is also applicable to a floor determination.  See 70 FR at
72335 n. 4.  

Fifth, regarding EPA’s argument that its emissions data do not reflect
performance over time, the commenter states that this 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:  First, 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.  Second, 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.  

Sixth, the 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 is statutorily
irrelevant.

General Response:  We disagree with all the points raised in the comment
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 CEM technology, or gathered any long term
emissions data we could use to set a national standard.  

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 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 Act, after
considering costs, energy impacts, and nonair 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 nonair adverse 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.  Therefore, any comparison of the mercury limits
for cement kilns that burn hazardous waste with cement kilns that do not
is misplaced.

	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 still is still 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, a
facility A may achieve lower mercury emission that 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 a 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
or 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 Act (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 the EPA’s choice to consider costs on the per ton of
emissions removed basis”.  

	Moreover, where Congress intended that economic achievability be the
means of assessing the reasonableness of costs of technology-based
environmental standards, it says so explicitly.  See Clean Water Act
section 301 (b) (2) (A) (direct dischargers of toxic pollutants to
navigable waters must meet standards reflecting “best available
technology economically achievable” (emphasis added). There is no such
explicit directive in section 112 (d)(2).  EPA accordingly does not
accept the commenter’s interpretation.

Comment:  Several comments support EPA’s decision not to develop
either an existing or new source floor for mercury.  The commenters
state that an achievable floor cannot be developed because wide
variation in mercury concentrations in raw materials and fuels used by
cement kilns would make compliance impossible.  One commenter also
agrees with EPA’s statement that a national conversion of cement kilns
to natural gas is not possible due to serious supply problems and the
lack of an adequate natural gas infrastructure. 

Response:  We agree with these comments insofar as they apply to floors
reflecting changes in 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, CA 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) 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.  Al 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 Toxic Release Inventory.  These data do not
differentiate between kilns that burn hazardous waste, which are a
different class of kiln subject to different regulations, and those that
do not.  Cement kilns that burn hazardous waste tend to be wet kilns and
also tend to have higher mercury emission than kilns that do not burn
hazardous waste, because of higher mercury levels in the hazardous waste
fuels burned by these kilns.  Therefore, the data cited by the commenter
do not support their conclusion.  

	Several commenters also suggested that EPA collect additional emission
test data from State and local agencies.  We collected additional data,
and have begun the process of gathering more.  See section IV.A.1.b
above, and the separate notice in today’s Federal Register announcing
reconsideration of the new source standard for mercury.  We believe
these data conclusively show that 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 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 ug/dscm for
new or existing cement kilns; 130 ug/dscm for hazardous waste
incinerators; 80 ug/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, NH3, NH4, HCl, HF
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 % reduction in SO2 which correlates to an emission rate of less
than 50ug/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% 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% 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 µg/dscm resulting from the hazardous waste alone (69 FR 21251,
April 20, 2004).  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 cement kiln dust (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 Portland Cement Association 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 activated carbon injection
(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 nonair quality impacts.  This would also be
the case if one combined ACI and reduced or eliminated the recycling of
CKD.  

	We 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.
 We rejected this later option because it would set a limit that has no
environmental benefit because it achieves no emissions reduction. See
section I.A. 1. b above. Another commenter mentioned the problems with
setting a limit based on changes to fuels, namely that limited supply
would preclude any MACT floor based on fuel switching, and would
likewise preclude any beyond-the-floor option. We agree with those
comments. See 70 FR 72334.

Comment: Several comments support EPA’s decision not to set
“beyond-the-floor” mercury standards for the following reasons: 1)
any possible activated carbon injection “back-end” control
technology would be prohibitively expensive, 2) the cost per mass of
mercury emissions reduced would be astronomical, and 3) the application
of such possible activated carbon injection would generate additional
solid waste and increase energy use.

Response: We agree with these comments for the reasons previously
discussed.   

Comment:  A commenter states that in the beyond-the-floor evaluation,
EPA failed to consider other control measures that reduce mercury
emissions. The commenter cited coal cleaning, mercury-specific  coal
treatments, optimization of existing control (the commenter supplied a
list of optimizing technologies), as well as currently available control
technologies such as enhanced wet scrubbing, Powerspan-ECO®, 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. (This later statement is
not supported by existing data, as explained in section I.A.1. b above.)
 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.  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.

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
Toxic Release Inventory (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 a 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 a 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 undercuts efforts to encourage
fish consumption as a way to reduce risk of heart disease. One commenter
states that in failing to set maximum degree of reduction standards that
are achievable, EPA did not consider the costs of not setting mercury
standards, including the public health costs of increased exposure to
mercury in children as well as the societal costs of contaminated water
bodies, fish, and other wildlife.

Response:  The purpose of 112(d) standards is to apply maximum
achievable control technology.    The consideration of impacts such as
those discussed above is performed during the section 112(f) residual
risk phase.  See Sierra Club v. EPA, 353 F. 3d 976, 989-90 (D.C. Cir.
2004) (rejecting the commenter’s argument).  We have begun this
analysis for this source category.  The results of this analysis will be
included in a separate rulemaking.  

Comment:  Several commenters raised concerns related to the local
impacts of industrial mercury emissions. According to one commenter, the
high temperature of cement kilns results in mercury emissions that fall
out and are deposited much closer to the source than was previously
thought. One commenter cites research that confirms that mercury
disproportionately affects nearby residents and that shows that nearly
70 percent of the mercury in an area’s rainwater comes from nearby
coal-burning industrial plants. One commenter states that EPA did not
consider impacts of mercury hot spots citing Florida and EPA research
showing a reduction in local and regional fish Hg levels when MACT
standards for medical and municipal incineration were implemented. The
commenter provided documentation of impacts on local environments of
lowering local or regional mercury emissions. One commenter 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 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-RCRA, 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% of kilns not
using fly ash account for 60% of mercury emissions, while the 36% that
do use fly ash account for about 40% of mercury emissions, do not
justify a conclusion that fly ash feedstock from utility boilers that
control mercury is a culprit in mercury emissions from cement kilns. 

Two commenters, 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 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 ug/g of
ash as evidence that EPA needs to limit the use of fly ash in cement and
should also evaluate other additives, including cement kiln dust, for
their mercury emissions potential. One commenter 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 Clean Air Mercury
Rule. They state that the higher mercury content of CCP used in
producing portland cement as well as the recycling of cement kiln dust
could cause mercury emissions to increase.

Several commenters 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 (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:  First, the comment is moot because EPA is not setting a
standard for HCl since emissions of this HAP from cement kilns will not
result in adverse effects on human health or the environment (with an
ample margin of safety), even under reasonable worst case assumptions as
to potential exposure.  See section IV.B above, and CAA section
112(d)(4).  Second, EPA did propose standards for HCl for both existing
and new sources, so the commenter’s claim that EPA disregarded the
court’s mandate at proposal is mistaken. 

Moreover, 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 control technologies, and had not examined all
available means of setting a standard.  As noted at proposal, we have
now reviewed all available control techniques to set a floor limit for
HCl emissions.  We considered the use of fuel and feed selection as the
basis for a standard, and found this approach to present the same
problems experienced with mercury. We continue to believe that these
facts preclude using these approaches as the basis of a MACT floor.
Setting some type of quantified emissions limit based on test data, as
the commenter states is mandated, would mean that many facilities,
including those which were the lowest emitting in individual tests,
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 nonair environmental impacts. 

	As discussed in the proposed amendments we are also unable to set any
percent reduction requirements (70 FR 72336).  

Comment:  Two commenters took issue with EPA’s definition of “new”
sources as it applies to the proposed HCl limits for new kilns.
Regarding EPA’s new source standards for HCl (15 ppmv or 90 percent
HCl reduction), one commenter states that EPA has created a compliance
loophole for kilns that commenced construction before December 2, 2005
and is unlawful. According to the commenter, the CAA defines new source
where construction or reconstruction commenced after the Administrator
“first” proposes regulations. The commenter states that EPA first
proposed standards on March 24, 1998 and that any kiln at which
construction or reconstruction was commenced after March 24, 1998 is a
new source and must meet new source standards. The commenter states that
EPA ignores that its violation of a clear statutory duty, (i.e., its
failure to promulgate HCl standards in the 1998 rulemaking), is the
reason that sources built after March 24, 1998 have not already
installed pollution controls necessary to meet new source HCl standards.

Response:  We disagree with these comments.  First, the comment is moot
with respect to an HCl new source standard because, based on the
authority of section 112 (d)(4),   EPA has determined that no such
standard is required. 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.

	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.  However, EPA did not propose standards
for mercury, hydrocarbons, or HCl for these sources until December 2,
2005; this is why the rule was remanded by the D.C. Circuit.  Hence, for
the HAPs covered by this rule, the new source trigger date must 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.

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
APCD. According to the commenter, “normal” kiln conditions may not
be best for HCl removal. This commenter also states that existing O&M
and SSM plans already ensure normal operation. Other commenters state
that this proposed work practice is arbitrary as there is no “normal
operating conditions” for all kilns in the U.S. The commenters state
that a multitude of factors – combustion parameters, kiln design, raw
material inputs, fuel characteristics, etc – make this requirement
unworkable. 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
standard for HCl based on the authority of section 112 (d) (4) of the
Act.  But we agree that “normal operating conditions” is not
particularly prescriptive.  As noted in the preamble to the proposed
amendments, the alkaline conditions within a cement kiln will result in
removal of a significant amount of HCl and the cement kiln itself
therefore acts as a “control device”.  The underlying intent was
simply to state that kiln and PM controls themselves represent the MACT
floor for existing sources.  The commenter did not provide any suggested
alternative language that would lead us to conclude there is a better
way to capture this intent in a regulation, had we pursued this
approach.   

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 standard for HCl based on the authority of section
112(d)(4) of the Act.  However, it now has relevance in regards to the
costs of controlling mercury emissions because we evaluated wet
scrubbers for mercury control after proposal.  We did further
investigate potential costs of alkaline (wet) scrubbers and revised our
cost estimates after proposal based on data developed as part of the
Industrial Boiler NESHAP.  The scrubber costs are based on alkaline
scrubbers specifically designed to remove HCl and/or SO2 from a
coal-fired boiler and we have made the required adjustments in cost to
account for differences in the flue gas characteristics of a cement kiln
versus a coal-fired boiler.  

The wet scrubbers that have been applied to cement kilns have SO2
guarantees of over 90 percent reduction or outlet concentrations of 10
ppmv.  Though this point is now moot, we continue to believe that
because HCl is more reactive than SO2, our proposed HCl limits of new
sources of 90 percent reduction or an outlet concentration of 15 ppmv
were very conservative.  In addition, we evaluated the performance of
wet scrubbers in municipal waste combustor and municipal waste
incinerators and on vendor design information and determined that an
alkaline scrubber could achieve 15 ppmv HCl outlet concentrations at low
inlet loadings or at least 90 percent HCl emissions reduction if the
inlet HCl level was 100 ppmv or more (63 FR 14203, March 24, 1998).  

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

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

Response:  This comment is moot given EPA’s decision not to set a
standard for HCl based on the authority of section 112 (d)(4) of the
Act.  However, as discussed previously in the response to a similar
comment on potential mercury beyond-the-floor standards, we believe that
“achievable” emission reductions under section 112 (d) (2) means
reductions that are achievable after consideration of costs, energy, and
non-air environmental impacts, consideration of which must be balanced
against potential emission reductions.  See Mossville, 370 F. 3d at 1236
(“[t]he EPA must balance these [emission reduction] considerations
with other factors such as cost, non-air quality health and
environmental concerns, and energy implications”).  The commenter also
claimed that we had not considered the limestone scrubbers and RTO
control in series.  This statement is incorrect.  We did consider
limestone scrubbers as a beyond-the-floor option of HCl control.  The
fact that at two facilities the limestone scrubber is followed by an RTO
has no implications for the overall level of HCl control because the RTO
will not remove additional HCl.  All potential HCl control occurs in the
limestone scrubber.  As discussed below, we did evaluate the performance
of a limestone scrubber/RTO control system as both new source MACT and
as an existing source MACT beyond-the-floor option for THC (non-dioxin
organic HAP) emissions.

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 reference concentration (RfC) for HCl the commenter states no
national risk-based HCl standard exists making it impossible to comment
effectively on any provisions in the cement rule that might rely on a
hypothetical future rulemaking. The commenter continues stating that any
attempt to set risk-based standards on a national rule that does not
exist and is not currently available for review, would contravene the
CAA notice and comment requirements. The commenter states further that
112(d)(4) allows EPA to set health-based emission standards only for
those pollutants for which a health threshold has been established, and
that no cancer threshold has been set for HCl (nor is there any
classification of HCl with respect to carcinogenicity and none exists). 
Also, the commenter states that no non-cancer threshold has been set for
HCl and that the IRIS RfC, on which EPA attempts to rely, does not
purport to be an established threshold. According to the commenter,
disclaimers in IRIS negate any notion that it provides an established
threshold for HCl.

Response:  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) 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 floor-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.  

	There are no data that suggest 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 reference concentration
(RfC) for inhalation.  An RfC is not a threshold for adverse effects,
but rather 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.  For a
substance having a robust toxicological database, the RfC may approach
the threshold; for a substance (such as HCl) for which the toxicological
database is sparse, the RfC incorporates multiple uncertainty factors
intended to place it at or below the threshold, which is unknown.  See (
 HYPERLINK "http://www.epa.gov/iris/subst/0396.htm" 
http://www.epa.gov/iris/subst/0396.htm ) for more information.

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 PH/PC kilns at 13 cement plants using a range of in-stack HCl
concentrations as well as a sensitivity analysis using higher HW kiln
HCl concentrations, risks are well below the short-term and long-term
thresholds. Based on this minimal risk, the commenters state that there
is no need for an HCl standard for new kilns or the proposed operational
standard for existing kilns. The commenters state that additional data
will be submitted to demonstrate that there is minimal risk and no need
for HCl standards. 

As stated in its comments on the original proposal, 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 reference
concentration (RfC) threshold for chronic health effects or Cal EPA’s
reference exposure level (REL) threshold for acute effects. Based on
these results, the commenter states that there is no justification for
an HCl standard for new or existing cement kilns. The commenter included
a copy of the health risk analysis with their comments. Another
commenter 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 PCA and agree that additional control of HCl is
not required.

Comment:  Regarding emission standards for total hydrocarbons (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
largely misplaced.  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
nonair 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 (EPA NOTE: 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), rather than setting
standards that reflect the THC or CO emission levels actually achievable
by the best performing sources (12% of cement kilns for existing and
best performing cement kiln for new). The commenter states further that
although maintaining good combustion conditions affects THC emissions,
it is not the only factor that does so and cites the plants’ selection
of raw materials as affecting THC emissions. The commenter states that
EPA’s new greenfield source standard reflects that use of low organic
feed materials affects THC emissions and also cites statements by
Florida DEP and Holcim that selection of feed materials can affect THC
emissions. The commenter states that EPA admits that add-on controls,
e.g., ACI and scrubber/RTO (in use on two kilns), as well as
precalciner/no preheater technology 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 NHW cement kiln should make it
easier to control the combustion process.” The commenter states that
EPA did not account for the fact that nonhazardous waste burning kilns
can control their combustion conditions and thus THC emission more
easily than hazardous waste burning kilns, instead just borrowing the
standard for hazardous waste burning kilns without attempting to show
that the proposed limits reflect what is actually achievable by the
relevant best performers. According to the commenter, EPA’s arguments
that it does not have to consider factors other than good combustion
were rejected by the court as irrelevant and EPA must set the THC limits
reflecting the average emission level that the best sources actually
achieve.

Response: 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.  

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.  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.  

Comments:  Several commenters state that it is inappropriate to set THC
floor limits based on a different source category, i.e., hazardous waste
combustors (HWC).  According to the commenters, at issue is the control
of products of incomplete combustion (PIC) vs. control of hydrocarbons
from feed materials. They state that HWC have the option 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. 

Comments:  Three commenters state that the HWC MACT standards were based
on EPA’s RCRA Boiler and Industrial Furnace (BIF) rules, which in turn
were based on the need to safely manage hazardous waste, a need that is
irrelevant to the facilities covered under the current proposal.

Response: 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.  Application of an RTO would allow new cement
kilns to meet a 20 ppmv standard.

Comments:  Three commenters state that EPA has no empirical data
demonstrating that any non-hazardous waste (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 of the new source floor is now a RTO. 
Application of an RTO would allow the facilities noted in the comment to
meet a 20 ppmv standard.

Comment:  Three commenters state that the contribution to THC/CO from
raw materials outweighs the measure of THC/CO for good combustion of
hazardous waste fuels. Thus, THC and CO are not useful indicators of
good combustion.  One commenter notes that available information shows
that it is difficult to correlate HC and HAP emissions.  The commenter
further states that several studies show that neither THC nor CO is a
reliable surrogate for good combustion or PIC or HAP emissions. 
According to the commenter, HC emissions are a function of 1) raw
material organic content, 2) source of fuel and firing location, 3)
temperature profile, 4) oxygen concentration, and 5) type of
manufacturing process. One commenter states that the high temperatures
required for the formation of cement clinker (>2700F) ensure as complete
combustion of fuels as is possible.

Response:  We agree with the comment that because organic contributions
from processing raw materials is the chief contributor to measured THC
levels (since such emissions are not combusted and hence are not largely
destroyed), having a quantified limit for THC as a measure of good
combustion is not appropriate for existing cement kilns that do not burn
hazardous waste.  We disagree with the more general statements regarding
the appropriateness of a THC indicator for organic HAP, and indeed are
continuing to utilize THC as an indicator for new sources.  As noted in
the proposal of the original NESHAP, the organic HAP component of THC
emissions varies widely (63 FR 14196).  However, THC emissions do
contain organic HAP.  Applying MACT to THC emissions will also control
organic HAP, but will be less costly than attempting to set individual
limits for each individual organic HAP (64 FR 31918).

	We also agree with the comment that combustion conditions in the hot
end of the kiln where fuels are fired should assure destruction of
organics (including organic HAP) in the fuel.  For this reason, we
adhere to our position at proposal that good combustion conditions in
the cement kiln should assure destruction of organic HAP in fuel and
represents the measure of best performance for reducing emissions of
organic HAP from existing cement kilns.  As explained in section I.C
above, we have chosen a different means of expressing good combustion
conditions than the quantified THC limit which we proposed.

Comment:  Three commenters state that it is inappropriate to apply
limits for non-dioxin organic HAP when feed materials have varying
levels of organics, which EPA acknowledges by setting THC limits only
for new greenfield sources (EPA also applied variability of feed/fuel
materials in justifying rules or lack of rules for mercury, HCl and
non-mercury metals).  Two commenters add that a Reaction Engineering
study shows that organics emitted from kiln feed is extremely variable
across the country with levels varying by over four orders of magnitude.

Response:  We agree with these comments and have made appropriate
changes in the final rule to the proposed floor for existing cement
kilns’ non-dioxin organic HAP emissions to account for the essentially
uncontrollable variability in organic HAP levels in raw materials.

Comment:  A commenter states that EPA failed to consider the reduction
in THC as part of the beyond-the-floor analysis of ACI. According to the
commenter, organic HAPs 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 good combustion practices; 2) EPA did
not show that its standards reflect the maximum degree of reduction
achievable through combustion controls in light of its findings that
nonhazardous waste burning kilns should be able to achieve the THC
standards more easily than hazardous waste burning kilns; 3) EPA did not
determine the maximum degree of reduction achievable through the
judicious selection of raw materials although they acknowledge that such
methods will control THC emissions and that kilns are already using it
and can control THC emissions through the use of other materials such as
fly ash and kilns can and do import raw materials from sources that are
not co-located or immediately nearby; 4) EPA did not determine the
degree of reduction achievable through the use of end-of-stack controls
already in use in the cement industry, including ACI, which EPA only
considered for mercury and dioxin control and which would reduce THC
emissions significantly and also reduce mercury and dioxin emissions EPA
NOTE: 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); 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.

Response:  We have no actual test data to establish the impact of ACI on
THC emissions.  There is one facility that uses ACI to reduce THC
emissions.  However, all the THC test data are after control.  We have
no data without control that would allow us to determine control
effectiveness in reducing THC emissions.  However, according to the
facility emission reductions are approximately 50 percent.  In addition,
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.  Therefore, we do not believe that the performance of
ACI at this facility on THC emissions can be extrapolated to the source
category as a whole.  However, we did evaluate the potential impacts of
ACI on THC emission using an assumed emission reduction of 50 percent. 
The results of this analysis are presented in section IV.A.2 above.  

	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
59462-63 (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 then those
nearby.  However, the fact that in some cases materials can be imported
from a farther distance does not change the fact that each individual
cement facility has specific raw materials needs based on their
particular limestone and other raw materials.  We do not have data, nor
are data available, to develop a national rule that would cover every
possible raw material substitution to reduce THC emissions. 

	The commenter also stated we did not assess the maximum degree of
emission reduction achievable through the use of end-of-stack controls. 
However, as previously discussed, there are no data available for us to
perform this analysis for any controls other then an RTO.  In the case
of an RTO, we have evaluated its performance as a beyond-the-floor
control.  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 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 it
is unlikely to perform any better than an RTO, and a viable alternative
as a beyond-the-floor option, 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 NESHAP we regulated THC
emissions from area sources because the THC emissions from a cement kiln
are likely to contain POM.  This pollutant is listed in section
112(c)(6) of the CAA as a pollutant for which we are specifically
required to establish regulations under section 112(d)(2).  The
commenter provided no data that would lead us to change this
determination (63 FR 14193-94).  Moreover, the commenter did not address
the argument that this result follows from section 112 (c) (6), so EPA
does not understand the comment that there is no legal authority to
support regulation of area source cement kiln emissions of HAP
enumerated in section 112 (c) (6). 

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, sources which commenced
construction or reconstruction after December 2, 2005, will have until
[INSERT DATE THREE YEARS FROM PUBLICATION IN THE FEDERAL REGISTER] to
comply.  See section 112(i)(1).    

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 gr/dscf; secondary crushers are subject to a 20
percent opacity limit. The commenter provided a copy of their State
requirements for crushers at cement manufacturing facilities.

One commenter 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 twenty new kilns wit 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 twenty new kilns the   SEQ CHAPTER \h \r 1 variation in mercury and
hydrocarbon emissions from kilns makes it difficult to quantify impacts
on a national basis with any accuracy.

For mercury emissions wwe estimate a new kiln with a capacity of 650,000
typ of climker will have an emission reduction ranging from zero to 280
pounds per year.  We estimate the national mercury emissions reduction
to be 1300 to 3000 pounds per year 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 amd 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 approximatley 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 fine particle emissions 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 5 willl 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 5th 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 scrubber. Although there will be no water quality impacts,
addition of a scrubber will increase water usage by about 41 million
gallons per year (gpy) for each new 650,000 tpy kiln that installs a
scrubber, or a national total of 460 million gpy.

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 RTOs
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 5th year.

F.  What are the cost impacts?

	The final rule amendments should impose minimal costs on existing
sources.  These costs will be recordkeeping costs for CKD wastage.  The
costs for new sources include the THC monitor and recordkeeping costs
for CKD wastage on all 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?	

The   SEQ CHAPTER \h \r 1 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 asserts 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
three of the 20 new kilns will have to install ACI, two the 20 new kilns
will be required to install a wet scrubber/RTO system to meet the limits
for THC, and five kilns will install a wet scrubber to meet the new
source mercury limits.  

Because of the high cost of transportation compared to the value of
Portland cement, the market for Portland cement is localized and
characterized by imperfect competition.  The possible outcomes of the
final amendments are either a deferral in bringing the new kiln into
production or a price increase in the immediate region around the two
new kilns that face control costs.  For perfect competition, control
costs at a new facility will be completely passed on in the long run to
the purchaser of the good.  With imperfect competition the outcome is
harder to predict.  Less than full cost pass through is a likely
possibility. 

The model new kilns used in this analysis has a clinker capacity of
650,000 tons/yr.  The annual control cost would be up to $597,000 for a
kilns that applies 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.

VII.  Statutory and Executive Order Reviews

A.  Executive Order 12866, Regulatory Planning and Review

	Under Executive Order 12866 (58 FR 51735, October 4, 1993), EPA must
determine whether the regulatory action is "significant" and, therefore,
subject to Office of Management and Budget (OMB) review and the
requirements of the Executive Order.  The Executive Order defines
"significant regulatory action" as one that is likely to result in a
rule that may:

	(1)  Have an annual effect on the economy of $100 million or more or
adversely affect in a material way, the economy, a sector of the
economy, productivity, competition, jobs, the environment, public health
or safety, or State, local, or tribal governments or communities; 

	(2)  create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;

 	(3)  materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs or the rights and obligations of recipients
thereof; or 

	(4)  raise novel legal or policy issues arising out of legal mandates,
the President's priorities, or the principles set forth in the Executive
Order.

	It   SEQ CHAPTER \h \r 1 was been determined that the proposed
amendments are not a "significant regulatory action" under the terms of
Executive Order 12866 and is, therefore, not subject to OMB review.  The
final amendments were determined to be a significant regulatory action
and are being submitted to OMB for review.    SEQ CHAPTER \h \r 1
Changes made in response to suggestions or recommendations from OMB will
be documented and included in the public record. 

B.  Paperwork Reduction Act

	The information collection requirements in the existing rule were
submitted to and approved by OMB under the Paperwork Reduction Act, 44
U.S.C. 3501, et seq., and assigned OMB control No. 2060-0416.  An
Information Collection Request (ICR) document was prepared by EPA (ICR
No. 1801.02) and a copy may be obtained from Susan Auby by mail at
Office of Environmental Information, Collection Strategies Division
(2822T), U.S. EPA, 1200 Pennsylvania Avenue, NW, Washington DC 20460, by
e-mail at auby.susan@epa.gov, or by calling (202) 566-1672.  A copy may
also be downloaded from the internet at http://www.epa.gov/icr.

	  SEQ CHAPTER \h \r 1 The information collection requirements in this
final rule have been submitted for approval to the Office of Management
and Budget (OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et
seq.  The Information Collection Request (ICR) document prepared by EPA
has been assigned EPA ICR number 1801.05.

	  SEQ CHAPTER \h \r 1 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
the 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 106 facilities over the first 3 years.  The estimated annual
average burden is outlined below 

Affected entity	Total Hours	Labor Costs	Total annual O&M costs	Total
Costs

Industry ......

Implementing .. Agency	4,447

357	$703,325

$22,962	$88,292

NA	$865,646

$25,362



	  SEQ CHAPTER \h \r 1 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.  

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 that has fewer than 750 employees; (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 today’s 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 six or seven 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 per
existing kiln is nominal.  The revenue for the entire small business
sector is estimated to be around $260 million (2003 dollars).  New
sources, will incur higher costs because new kilns must install a THC
monitor, and approximately three of the 20 new kilns will have to
install ACI 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
the CAA.  Further, the costs of required performance testing and
monitoring for new sources have been minimized by specifying emissions
limits and monitoring parameters in terms of surrogates for HAP
emissions, which are less costly to measure.  

D.  Unfunded Mandates Reform Act

  SEQ CHAPTER \h \r 1  	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.

	The 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,
today's 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.

	The EPA interprets Executive Order 13045 as applying only to those
regulatory actions that are based on health or safety risks, such that
the analysis required under section 5-501 of the Executive Order has the
potential to influence the rule.  The final rule amendments are not
subject to Executive Order 13045 because they are based on technology
performance and not on health or safety risks.

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

	This rule is not a “significant energy action” as defined in
Executive Order 13211, “Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use” (66 FR 28355
(May 22, 2001)) because it is not likely to have a significant adverse
effect on the supply, distribution, or use of energy.  These rule
requirements will have energy effects due to the energy requirements for
the control devices required for new sources.  We estimate the
additional electrical demand to be 15 million kWhr per year and the
natural gas use to be 270 billion cubic feet by the end of the 5th 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 (Public Law No. 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.  The 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.  The EPA determined that these two
standards identified for measuring emissions of the HAPs 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 the 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
the EPA method requires the use of six impingers.  In addition, EN 13211
does not include many of the quality control procedures of the 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 the 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 the 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 the 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 the EPA method.

	Section 63.1349 to subpart LLL of this rule lists the testing methods
included in the regulation.  Under §63.7(f) and §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 [INSERT THE DATE OF PUBLICATION OF THE FINAL AMENDMENTS IN
THE FEDERAL REGISTER].

List of Subjects in 40 CFR Part 63

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

  SEQ CHAPTER \h \r 1 ______________

Dated:

______________________

Stephen L. Johnson,

Administrator.

 

  SEQ CHAPTER \h \r 1 For the reasons stated in the preamble, title 40,
chapter I, part 63 of the Code of the Federal Regulations is amended as
follows:

PART 63--[AMENDED]

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

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

Subpart LLL-[AMENDED]	

2.  §63.1342 is revised to read as follows:

§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.

3.  Section 63.1343 is revised to read as follows:

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

	(a)  General.  The provisions in this section apply to each kiln, each
in-line kiln/raw mill, and any alkali bypass associated with that kiln
or in-line kiln/raw mill.  All gaseous, mercury and D/F emission limits
are on a dry basis, corrected to 7 percent oxygen.  All total
hydrocarbon (THC) emission limits are measured as propane.  The block
averaging periods to demonstrate compliance are hourly for 20 ppmv total
hydrocarbon (THC) limits and monthly for the 50 ppmv THC limit.  	

(b) Existing kilns located at major sources. No owner or operator of an
existing kiln or an existing kiln/raw mill located at a facility that is
a major source subject to the provisions of this subpart shall cause to
be discharged into the atmosphere from these affected sources, any gases
which:

(1) Contain particulate matter (PM) in excess of 0.15 kg per Mg (0.30 lb
per ton) of feed (dry basis) to the kiln. When there is an alkali bypass
associated with a kiln or in-line kiln/raw mill, the combined
particulate matter emissions from the kiln or in-line kiln/raw mill and
the alkali bypass are subject to this emission limit.

(2) Exhibit opacity greater than 20 percent.

(3) Contain D/F in excess of:

(i) 0.20 ng per dscm (8.7×10−11 gr per dscf) (TEQ); or

(ii) 0.40 ng per dscm (1.7×10−10 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 °C (400 °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 (8.7×10−11 gr per dscf) (TEQ; or

(ii) 0.40 ng per dscm (1.7×10−10 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 °C (400 °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 alternate 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 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
µg/dscm if the source is a new or reconstructed source that commenced
construction after December 2, 2005.  As an alternate to meeting the 41
µg/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.  

	(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:

−11 gr per dscf) (TEQ); or

(2) Contain D/F in excess of 0.40 ng per dscm (1.7×10−10 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 °C (400
°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:

−11 gr per dscf) (TEQ; or

(ii) 0.40 ng per dscm (1.7×10−10 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 °C (400 °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 alternate 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 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
µg/dscm if the source is a new or reconstructed source that commenced
construction after December 2, 2005.  As an alternate to meeting the 41
µg/dscm standard you may route the emissions through a packed bed or
spray tower wet scrubber with a l/g ratio of 30 gallons per 1000 acfm or
more.  

4.  Section 63.1344 is amended as follows: 

a.  revising paragraphs (c) through (e);

b.  adding add apragraphs(f) through (i) 

§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 §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 §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 §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 §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 §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 §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.  Good combustion practices include training all operators
and supervisors to operate and maintain the kiln and calciner, and
pollution control systems in accordance with good engineering practices.
The training shall include good operating practices as well as methods
for minimizing excess emissions. 

	(g)  All kilns and in-line kilns/raw mills may not 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).

	(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 avrage hourly CKD recycle rate measured during mercury
performance testing.  Any exceedance of this average hourly rate is
considered a violation of the standard.

5.  Section 63.1346 is revised to read as follows:

§ 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:

(i)  exhibit opacity greater than ten percent, or 

(ii)  contain THC in excess of 20 ppmv, on a dry basis as propane
corrected to 7 percent oxygen if the source commenced construction on or
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 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 can not 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 on or 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 prior to December 2, 2005, then the THC
limit is 50 ppmv, on a dry basis corrected to 7 percent oxygen.

6.  Section 63.1349 is amended as follows: 

a.  By revising paragraph (b)(4) 

b.  By adding paragraph (b)(5) 

c.  By removing paragraph (f). 

§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 µg/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 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.

* * * * *

7.  Section 63.1350 is amended revising paragraphs (g), (h) and (n) to
read as follows:

§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 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 specificed in 40 CFR part
63 subpart SS.	

* * * * *

	8.  Section 63.1351 is revised to read as follows:

§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 good combustion practices is [INSERT DATE ONE YEAR FROM
PUBLICATION IN THE FEDERAL REGISTER].  

(d)  The compliance date for a new source to meet the THC emission limit
of 20 ppmv/98 percent reduction or the mercury standard of 41 µg/dscm
or application of a wet scrubber will be startup or [INSERT DATE THREE
YEARS FROM PUBLICATION IN THE FEDERAL REGISTER], whichever is later.   

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

§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.

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

§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.

* * * * *

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.

 A new greenfield kiln is a kiln constructed after March 24, 1998 at a
site where there are no existing kilns. 

 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 nonair environmental impacts. 70 FR 72335.

 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.

 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.  

 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).

 See section c. below discussing operation of the in-line raw mill and
its implication for mercury control.

 EPA does not consider adopting an astronomically high mercury standard
(a standard so high as never to be exceeded) as being a productive
alternative.  70 FR 72334.

 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.

 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.

 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°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. 

 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 per cent 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.  

 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 per cent of incoming mercury.  

 On the other hand, 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.  Thus,
we do not view utility boilers as a “similar source” for purposes of
section 112(d)(1).  

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 None of these five kilns burn hazardous waste.

 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.

                            .  

 As it happens, under this rule, new sources would have three years to
comply with new source standards 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. 

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

 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. 

 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.

 For the same reason, area source cement kilns are required to control
dioxin, another HAP enumerated in section 112 (c) (6).  See 40 CFR
63.1343.

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