Federal Register: September 9, 2010 (Volume 75, Number 174)
DOCID: fr09se10-14 FR Doc 2010-21102
ENVIRONMENTAL PROTECTION AGENCY
Veterans Affairs Department
CFR Citation: 40 CFR Parts 60 and 63
RIN ID: RIN 2060-AO15, 2060-AO42
EPA ID: [EPA-HQ-OAR-2002-0051; EPA-HQ-OAR-2007-0877; FRL-9189-2]
NOTICE: Part II
DOCUMENT ACTION: Final rule.
National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing Industry and Standards of Performance for Portland Cement Plants
DATES: These final rules are effective on November 8, 2010. The incorporation by reference of certain publications listed in this rule is approved by the Director of the Federal Register on November 8, 2010.
EPA is finalizing amendments to the National Emission Standards for Hazardous Air Pollutants (NESHAP) from the Portland Cement Manufacturing Industry and to the New Source Performance Standards (NSPS) for Portland Cement Plants.
The final amendments to the NESHAP add or revise, as applicable, emission limits for mercury, total hydrocarbons (THC), and particulate matter (PM) from new and existing kilns located at major and area sources, and for hydrochloric acid (HCl) from new and existing kilns located at major sources. The standards for new kilns apply to facilities that commence construction, modification, or reconstruction after May 6, 2009.
The final amendments to the NSPS add or revise, as applicable,
emission limits for PM, opacity, nitrogen oxides (NO
Environmental Protection Agency
The supplementary information presented in this preamble is organized as follows:
I. General Information
A. Does this action apply to me?
B. Where can I get a copy of this document?
C. Judicial Review
II. Background Information on the NESHAP, 40 CFR Part 63, Subpart LLL
A. What is the statutory basis for the NESHAP in 40 CFR part 63, subpart LLL?
B. Summary of the National Lime Association v. EPA Litigation
C. EPA's Response to the Remand
D. Reconsideration of EPA Final Action in Response to the Remand III. Background Information From the NSPS 40 CFR Part 60, Subpart F IV. Summary of EPA's Final Action on Amendments
A. What are EPA's final actions on 40 CFR part 63, subpart LLL?
B. What are EPA's final actions on 40 CFR part 60, subpart F?
C. What is EPA's sectorbased approach?
V. Responses to Major Comments
A. What are the significant comments and responses on 40 CFR part 63, subpart LLL?
B. What are the significant comments and responses on 40 CFR part 60, subpart F?
VI. Summary of Cost, Environmental, Energy, and Economic Impacts of the Final Amendments to Subpart LLL and Subpart F
VII. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
B. Paperwork Reduction Act
C. Regulatory Flexibility Act
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 Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use
I. National Technology Transfer Advancement Act
J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and LowIncome Populations
K. Congressional Review Act
I. General Information
A. Does this action apply to me?
Categories and entities potentially regulated by this final rule include:
Category code \1\ Examples of regulated entities Industry............................... 327310 Portland cement manufacturing plants. Federal government..................... ......... Not affected. State/local/Tribal government.......... ......... Portland cement manufacturing plants. \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. To determine whether your facility will be regulated by this action, you should examine the applicability criteria in 40 CFR 60.60 (subpart F) or in 40 CFR 63.1340 (subpart LLL). If you have any questions regarding the applicability of this final action to a particular entity, contact the person listed in the preceding FOR FURTHER INFORMATION CONTACT section.
B. Where can I get a copy of this document?
In addition to being available in the docket, an electronic copy of
this final action is available on the Worldwide Web (WWW) through the Technology Transfer Network (TTN). Following
signature, a copy of this final action will be posted on the TTN's policy and guidance page for newly proposed or promulgated rules at http://www.epa.gov/ttn/oarpg. The TTN provides information and technology exchange in various areas of air pollution control. C. Judicial Review
Under section 307(b)(1) of the Clean Air Act (CAA), judicial review of these final rules are available only by filing a petition for review in the United States Court of Appeals for the District of Columbia Circuit by November 8, 2010. Under section 307(b)(2) of the CAA, the requirements established by these final rules may not be challenged separately in any civil or criminal proceedings brought by EPA to enforce these requirements.
Section 307(d)(7)(B) of the CAA further provides that ``[o]nly an
objection to a rule or procedure which was raised with reasonable
specificity during the period for public comment (including any public
hearing) may be raised during judicial review.'' This section also provides a mechanism for EPA to convene a proceeding for
reconsideration, ``[i]f the person raising an objection can demonstrate to EPA that it was impracticable to raise such objection within [the period for public comment] or if the grounds for such objection arose after the period for public comment (but within the time specified for judicial review) and if such objection is of central relevance to the outcome of the rule.'' Any person seeking to make such a demonstration to us should submit a Petition for Reconsideration to the Office of the Administrator, U.S. EPA, Room 3000, Ariel Rios Building, 1200 Pennsylvania Ave., NW., Washington, DC 20460, with a copy to both the person(s) listed in the preceding FOR FURTHER INFORMATION CONTACT section, and the Associate General Counsel for the Air and Radiation Law Office, Office of General Counsel (Mail Code 2344A), U.S. EPA, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
II. Background Information on the NESHAP, 40 CFR Part 63, Subpart LLL A. What is the statutory basis for the NESHAP in 40 CFR part 63, subpart LLL?
Section 112 of the CAA establishes a regulatory process to address emissions of hazardous air pollutants (HAP) from stationary sources. After EPA has identified categories of sources emitting one or more of the HAP listed in section 112(b) of the CAA, section 112(d) requires us to promulgate NESHAP for those sources. For ``major sources'' that emit or have the potential to emit 10 tons per year (tpy) or more of a single HAP or 25 tpy or more of a combination of HAP, these technology based standards must reflect the maximum reductions of HAP achievable (after considering cost, energy requirements, and nonair quality health and environmental impacts) and are commonly referred to as maximum achievable control technology (MACT) standards.
The statute specifies certain minimum stringency requirements for MACT standards, which are referred to as ``floor'' requirements. See CAA section 112(d)(3). Specifically, for new sources, the MACT floor cannot be less stringent than the emission control that is achieved in practice by the best controlled similar source. The MACT standards for existing sources can be less stringent than standards for new sources, but they cannot be less stringent than the average emission limitation achieved by the bestperforming 12 percent of existing sources (for which the Administrator has emissions information) in the category or subcategory (or the bestperforming five sources for categories or subcategories with fewer than 30 sources).
In developing MACT, we must also consider control options that are more stringent than the floor. We may establish standards more stringent than the floor based on the consideration of the cost of achieving the emissions reductions, any nonair quality health and environmental impacts, and energy requirements. CAA section 112(d)(2).
Section 112(k)(3)(B) of the CAA requires EPA to identify at least
30 HAP that pose the greatest potential health threat in urban areas,
and section 112(c)(3) requires EPA to regulate, under section 112(d)
standards, the area source \1\ categories that represent 90 percent of
the emissions of the 30 ``listed'' HAP (``urban HAP''). We implemented
these listing requirements through the Integrated Urban Air Toxics Strategy (64 FR 38715, July 19, 1999).\2\
\1\ An area source is a stationary source of HAP emissions that is not a major source. A major source is a stationary source that emits or has the potential to emit 10 tpy or more of any HAP or 25 tpy or more of any combination of HAP.
\2\ Since its publication in the Integrated Urban Air Toxics Strategy in 1999, EPA has amended the area source category list several times.
The Portland cement manufacturing source category was listed for regulation under this 1999 Urban Strategy based on emissions of arsenic, cadmium, beryllium, lead, and polychlorinated biphenyls (PCB). The final NESHAP for the Portland Cement Manufacturing Industry (64 FR 31898, June 14, 1999) included emission limits based on performance of MACT for the control of THC emissions from area sources. This 1999 rule fulfills the requirement to regulate area source cement kiln emissions of PCB (for which THC is a surrogate). However, EPA did not include requirements for the control of the nonvolatile metal HAP (arsenic, cadmium, beryllium, and lead) from area sources in the 1999 rule or in the 2006 amendments. To fulfill our requirements under CAA section 112(c)(3) and 112(k), EPA is thus setting emissions standards for these metal HAP from Portland cement manufacturing facilities that are area sources (using PM as a surrogate). In this final rule EPA is promulgating PM standards for area sources based on performance of MACT, PM being a surrogate for these (and other nonvolatile) HAP metals.
Section 112(c)(6) requires that EPA list categories and subcategories of sources assuring that sources accounting for not less than 90 percent of the aggregate emissions of each of seven specified HAP are subject to standards under section 112(d)(2) or (d)(4). The seven HAP are as follows: Alkylated lead compounds; polycyclic organic matter; hexachlorobenzene; mercury; polychlorinated byphenyls; 2,3,7,8 tetrachlorodibenzofurans; and 2,3,7,8tetrachloroidibenzopdioxin. Standards established under CAA section 112(d)(2) must reflect the performance of MACT. ``Portland cement manufacturing: Nonhazardous waste kilns'' is listed as a source category pursuant to CAA section 112(c)(6) due to emissions of polycyclic organic matter (POM), mercury, and dioxin/furans. Consistent with the requirements of CAA section 112(c)(6), we set MACT standards for these pollutants. 63 FR 17838, 17848, April 10, 1998; see also 63 FR at 14193 (March 24, 1998) (area source cement kilns' emissions of mercury, dibenzopdioxins and dibenzopfurans, POM, and PCB are subject to MACT).
Section 129(a)(1)(A) of the CAA requires EPA to establish specific
performance standards, including emission limitations, for ``solid
waste incineration units'' generally, and, in particular, for ``solid
waste incineration units combusting commercial or industrial waste'' (CAA section 129(a)(1)(D)).\3\
\3\ CAA section 129 refers to the Solid Waste Disposal Act (SWDA). However, this Act, as amended is commonly referred to as RCRA.
Section 129 of the CAA defines ``solid waste incineration unit'' as ``a distinct operating unit of any facility which combusts any solid waste material from commercial or industrial establishments or the general public.'' CAA Section 129(g)(1). CAA Section 129 also provides that ``solid waste'' shall have the meaning established by EPA pursuant to its authority under the Resource Conservation and Recovery Act (RCRA). Section 129(g)(6).
In Natural Resources Defense Council v. EPA, 489 F. 3d 1250, 1257 61 (DC Cir. 2007), the Court vacated the Commercial and Industrial Solid Waste Incineration Units (CISWI) Definitions Rule, 70 FR 55568 (Sept. 22, 2005), which EPA issued pursuant to CAA section 129(a)(1)(D).
In response to the Court's remand and vacatur of the CISWI Definitions rule, EPA initiated a rulemaking to identify which secondary materials are nonhazardous ``solid waste'' for purposes of subtitle D (nonhazardous waste) of the RCRA when burned in a combustion unit. See 75 FR 31844 (June 4, 2010). Any final definition adopted in that rulemaking, in turn, will determine the applicability of CAA section 129(a) (i.e., any combustion unit that burns any non hazardous secondary material that is considered to be a solid waste would be subject to CAA section 129 requirements).
There is presently no Federal regulatory interpretation of ``solid waste'' for EPA to apply under Subtitle D of RCRA for purposes of CAA section 112 and 129. EPA is not prejudging, and cannot prejudge the outcome of the recently proposed nonhazardous solid waste rulemaking. EPA therefore cannot reliably determine at this time if the non hazardous secondary materials combusted by cement kilns are to be classified as solid wastes. Accordingly, EPA is basing all determinations as to source classification on the emissions information now available, as required by CAA section 112(d)(3), and will necessarily continue to do so until the solid waste definition discussed above is promulgated. The current data base classifies all Portland cement kilns as CAA section 112 sources (i.e., subject to regulation under CAA section 112).
We proposed amendments to the Portland Cement Manufacturing NESHAP
on May 6, 2009. See 74 FR 21136. We received a total of 3,229 comments
from the Portland cement industry, environmental groups, State
environmental agencies and others during the comment period. This final
rule reflects our consideration of all the comments we received.
Detailed responses to the comments not included in this preamble are
contained in the Summary of Public Comments and Responses document, which is included in the docket for this rulemaking.
B. Summary of the National Lime Association v. EPA Litigation
On June 14, 1999 (64 FR 31898), EPA issued the NESHAP for the
Portland Cement Manufacturing Industry (40 CFR part 63, subpart
LLL).\4\ The 1999 final rule established emission limitations for PM as
a surrogate for nonvolatile HAP metals (major sources only), dioxins/
furans, and for greenfield \5\ new sources total THC as a surrogate for
organic HAP. These standards were intended to be based on the
performance of MACT pursuant to CAA sections 112(d)(2) and (3). We did
not establish limits for THC for existing sources and nongreenfield
new sources, nor for HCl or mercury for new or existing sources. We
reasoned that emissions of these constituents were a function of raw
material concentrations and so were essentially uncontrolled, the
result being that there was no level of performance on which a floor
could be based. EPA further found that beyond the floor standards for these HAP were not warranted.
\4\ Cement kilns which burn hazardous waste are a separate source category, since their emissions of many HAP differ from Portland cement kilns' as a result of the hazardous waste inputs. Rules for hazardous wasteburning cement kilns are found at subpart EEE of part 63.
\5\ For purposes of the 1999 rule a new greenfield kiln is a kiln constructed after March 24, 1998, at a site where there are no existing kilns.
Ruling on petitions for review of various environmental groups, the
DC Circuit held that EPA had erred in failing to establish CAA section
112(d) standards for mercury, THC (except for greenfield new sources)
and HCl. The court held that ``[n]othing in the statute even suggests
that EPA may set emission levels only for those * * * HAPs controlled
with technology.'' National Lime Ass'n v. EPA, 233 F. 3d 625, 633 (DC
Cir. 2000). The court also stated that EPA is obligated to consider
other pollutionreducing measures such as process changes and material
substitution. Id. at 634 (``the absence of technologybased pollution
control devices for HCl, mercury, and total hydrocarbons did not excuse
EPA from setting emission standards for those pollutants''). Later
cases go on to hold that EPA must account for levels of HAP in raw
materials and other inputs in establishing MACT floors, and further
hold that sources with low HAP emission levels due to low levels of HAP
in their raw materials can be considered best performers for purposes
of establishing MACT floors. See, e.g., Cement Kiln Recycling Coalition
v. EPA, 255 F. 2d 855, 86566 (DC Cir. 2001); Sierra Club v. EPA (``Brick MACT''), 479 F. 3d 875, 88283 (DC Cir. 2007).\6\
\6\ In the remainder of the opinion, the Court in National Lime Ass'n upheld EPA's standards for PM and dioxin (on grounds that petitioner had not properly raised arguments in its opening brief), upheld EPA's use of PM as a surrogate for HAP metals, and remanded for further explanation EPA's choice of an analytic method for HCl. C. EPA's Response to the Remand
In response to the National Lime Ass'n mandate, on December 2,
2005, we proposed standards for mercury, THC, and HCl. (More
information on the regulatory and litigation history may be found at 70
FR 72332, December 2, 2005.) We received over 1,700 comments on the
proposed amendments. Most of these comments addressed the lack of a
mercury emission limitation in the proposed amendments. On December 20,
2006 (71 FR 76518), EPA published final amendments to the NESHAP. The
2006 amendments contained a new source standard for mercury emissions
from cement kilns and kilns/inline raw mills of 41 micrograms per dry
standard cubic meter, or alternatively the application of a limestone
wet scrubber with a liquidtogas ratio of 30 gallons per 1,000 actual
cubic feet per minute of exhaust gas. The final rule also adopted a
standard for new and existing sources 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 cement kiln seeking to use the fly ash can demonstrate that
the use of fly ash will not result in an increase in mercury emissions
over its baseline mercury emissions (i.e., emissions not using the
mercuryladen fly ash). EPA also issued a THC standard for new cement
kilns (except for greenfield cement kilns that commenced construction
on or before December 2, 2005) of 20 parts per million (corrected to 7
percent oxygen) or 98 percent reduction in THC emissions from
uncontrolled levels. EPA did not set a standard for HCl, determining
that HCl was a pollutant for which a threshold had been established,
and that no cement kiln, even under conservative operating conditions
and exposure assumptions, would emit HCl at levels that would exceed
that threshold level, allowing for an ample margin of safety. EPA
pointed to CAA section 112(d)(4) authority as its rationale for not establishing HCl emissions limits.
D. Reconsideration of EPA Final Action in Response to the Remand
At the same time we issued the final amendments, EPA on its own initiative made a determination to reconsider the new source standard for mercury, the existing and new source standard banning cement kiln use of certain mercurycontaining fly ash, and the new source standard for THC (71 FR 76553, December 20, 2006). EPA granted reconsideration of the new source mercury standard both due to substantive issues relating to the performance of wet scrubbers and because information about their performance in the industry had not been available for public comment at the time of proposal; that information is now available in the docket. We also committed to undertake a test program for mercury emissions from cement kilns equipped with wet scrubbers that would enable us to resolve these issues. We further explained that we were granting reconsideration of the work practice requirement banning the use of certain mercurycontaining fly ash in cement kilns to allow further opportunity for comment on both the standard and the underlying rationale and because we did not feel we had the level of analysis we would like to have to support a beyondthefloor determination. We granted reconsideration of the new source standard for THC because the information on which the standard was based arose after the period for public comment. We requested comment on the actual standard, whether the standard is appropriate for reconstructed new sources (if any should occur) and the information on which the standard is based. We specifically solicited data on THC emission levels from preheater/precalciner cement kilns. We stated that we would evaluate all data and comments received, and determine whether in light of those data and comments it was appropriate to amend the promulgated standards.
EPA received comments on the notice of reconsideration from two
cement companies, three energy companies, three industry associations,
a technical consultant, one State, one environmental group, one ash
management company, one fuels company, and one private citizen. As part
of these comments, one industry trade association submitted a petition
to withdraw the new source MACT standards for mercury and THC and one
environmental group submitted a petition for reconsideration of the
2006 final action. A summary of these comments is available in the docket for this rulemaking.\7\
\7\ Summary of Comments on December 20, 2006 Final Rule and Notice of Reconsideration. April 15, 2009.
In addition to the reconsideration discussed above, EPA received a
petition from Sierra Club requesting reconsideration of the existing
source standards for THC, mercury, and HCl, and judicial petitions for review challenging the final amendments. EPA granted the
reconsideration petition. The judicial petitions have been combined and are being held in abeyance pending the results of the reconsideration.
In March 2007 the DC Circuit Court issued an opinion (Sierra Club
v. EPA, 479 F.3d 875 (DC Cir. 2007) (Brick MACT)) vacating and
remanding CAA section 112(d) MACT standards for the Brick and
Structural Clay Ceramics source categories. Some key holdings in that case were:
Based on the statute, as interpreted in the Brick MACT decision, we believe a source's performance resulting from the presence or absence of HAP in raw materials must be accounted for in establishing floors; i.e., a low emitter due to low HAP proprietary raw materials can still be a best performer. In addition, the fact that a specific level of performance is not being intentionally achieved by the source is not a legal basis for excluding the source's performance from consideration. Sierra Club v. EPA, 479 F.3d at 63134; National Lime Ass'n, 233 F. 3d at 640.
The Brick MACT decision also reiterated that EPA may account for variability in setting floors. However, the Court found that EPA erred in assessing variability because it relied on data from the worst performers to estimate best performers' variability, and held that ``EPA may not use emission levels of the worst performers to estimate variability of the best performers without a demonstrated relationship between the two.'' 479 F. 3d at 882.
After considering the implications of this decision, EPA granted the petition for reconsideration of all the existing source standards in the 2006 rulemaking.
A second Court opinion of relevance to the Portland cement NESHAP
amended here is Sierra Club v. EPA, 551 F. 3d 1019 (DC Cir. 2008). In
that case, the court vacated the regulations contained in the General
Provisions which exempt major sources from CAA section 112(d) standards
during periods of startup, shutdown and malfunction (SSM). The
regulations (in 40 CFR 63.6(f)(1) and 63.6(h)(1)) provided that sources
need not comply with the relevant CAA section 112(d) standard during
SSM events and instead must ``minimize emissions * * * to the greatest
extent which is consistent with safety and good air pollution control
practices.'' The current Portland Cement NESHAP references the now
vacated rules in the General Provisions. As a result of the court's
decision, we are removing the references to the vacated provisions and
addressing SSM in this rulemaking. Discussion of this issue may be found in Section IV.A.
III. Background Information on the NSPS 40 CFR Part 60, Subpart F
NSPS implement CAA section 111(b) and are issued for categories of sources which cause, or contribute significantly to, air pollution which may reasonably be anticipated to endanger public health or welfare. The primary purpose of the NSPS is to attain and maintain ambient air quality by ensuring that the best demonstrated emission control technologies are installed as the industrial infrastructure is modernized. Since 1970, the NSPS have been successful in achieving longterm emissions reductions in numerous industries by assuring cost effective controls are installed on new, reconstructed, or modified sources.
Section 111 of the CAA requires that NSPS reflect the application
of the best system of emission reductions which, taking into
consideration the cost of achieving such emission reductions, any non
air quality health and environmental impact and energy requirements, the Administrator determines has been adequately
demonstrated. This level of control is commonly referred to as best demonstrated technology (BDT). EPA promulgated Standards of Performance for Portland Cement Plants (40 CFR, part 61 subpart F) in 1971 ((36 FR 24876, December 23, 1971).
Section 111(b)(1)(B) of the CAA requires EPA to periodically review and revise the standards of performance, as necessary, to reflect improvements in methods for reducing emissions. We have conducted three reviews of the standards (39 FR 20793, June 14, 1974; 39 FR 39874, November 12, 1974; and 53 FR 50354, December 14, 1988).
We proposed the current review of the Portland Cement Plant NSPS on June 16, 2008. We received a total of 46 comments from the Portland cement industry, environmental groups, State environmental agencies and others during the comment period. This final rule reflects our consideration of all the comments we received. Detailed responses to the comments not included in this preamble are contained in the Summary of Public Comments and Responses document which is included in the docket for this rulemaking.
IV. Summary of EPA's Final Action on the Amendments
In this section we discuss the final amendments to 40 CFR part 63 subpart LLL and part 60 subpart F, the changes since proposal, and the rationale for the changes. Responses to specific comments may be found in the response to comment section of this document or in the response to comment documents contained in the dockets for this rulemaking.
As a preliminary matter, EPA notes that certain portions of the existing rules are not being amended substantively but are being reprinted, sometimes with editorial changes, in today's regulatory text. As explained at proposal, EPA did so either for readers' convenience or to make certain nonsubstantive ``plain English'' changes to rule text. 74 FR at 21140. The final rule text makes these same nonsubstantive changes (which did not occasion public comment), and reprints certain existing provisions. Provisions from the existing rules which do not change substantively include the PM emission limits for kilns currently subject to the NSPS, the opacity limits for raw materials dryers, raw mills, and finish mills, and the limits for dioxin furan (D/F) for cement kilns. We reorganized the testing and monitoring requirements of both rules to make them more consistent, and modified the rule language to better conform with the June 1, 1998, Executive Memorandum on Plain Language in Government Writing. A. What are EPA's final actions on 40 CFR part 63, subpart LLL? 1. What are the final actions on emission limits under 40 CFR part 63, subpart LLL?
In this action, we are amending the emission limits for mercury, THC, and PM from new and existing kilns located at a major or area source, and for HCl from new and existing kilns located at major sources. We identify these standards below for the emission sources in a typical Portland cement production process. We have applied the limits for existing and new sources in this final rule for mercury and THC to area sources consistent with CAA section 112(c)(6). As noted above, mercury is one of the pollutants specifically singled out by Congress in CAA section 112(c)(6), and THC is a surrogate for POM and PCB, which are also section 112(c)(6) HAP. See 63 FR 14193, March 24, 1998 (determination to control all THC emissions from the source category under MACT standards). Finally, Portland cement kilns are a listed area source category for urban HAP metals pursuant to CAA section 112(c)(3), and control of these metal HAP emissions (via the standard for the PM nonmercury HAP metal surrogate) is required to ensure that area sources representing 90 percent of the area source emissions of urban metal HAP are subject to CAA section 112 control, as required by CAA section 112(c)(3). The PM standards for area sources reflect MACT, as explained below.
a. Changes to Overall Floor Setting Procedure
The MACT floor limits for each of the HAP and HAP surrogates (mercury, THC, HCl, and PM) are calculated based on the performance of the lowest emitting (considered best performing in this rulemaking) sources in each of the MACT floor pools for each HAP or HAP surrogate. We ranked all of the sources for which we had data based on their emissions and identified the lowest emitting 12 percent of the sources for which we had data, which ranged from two kilns for THC to 11 kilns for mercury for existing sources. For new source MACT, the floor was based on the best controlled source.
In assessing sources' performance, EPA may consider variability both in identifying which performers are ``best'' and in assessing their level of performance. Brick MACT, 479 F. 3d at 88182; see also Mossville Envt'l Action Now v. EPA, 370 F.3d 1232, 124142 (DC Cir 2004) (EPA must exercise its judgment, based on an evaluation of the relevant factors and available data, to determine the level of emissions control that has been achieved by the best performing sources considering these sources' variability).
Variability in cement kilns' performance has a number of causes.
For many of the pollutants, notably mercury and THC, most kilns do not
have addon control devices. The main source of variability for these
pollutants consequently is the differing mercury and organic
concentrations in the raw materials and fuels which are fed to the
kiln. For particulate matter, which is wellcontrolled by baghouses,
the variability is chiefly due to variations in performance of the
control device for which both runtorun and testtotest variability must be accounted.\8\
\8\ Runtorun variability is essentially withintest
variability, and encompasses variability in individual runs comprising the compliance test, and includes uncertainties in correlation of monitoring parameters and emissions, and imprecision of stack test methods and laboratory analysis. 72 FR at 54877 (Sept. 27, 2007). Testtotest variability results from variability in pollution device control efficiencies over time (depending on many factors, including for fabric filters the point in the maintenance cycle in which a fabric filter is tested). Testtotest variability can be termed longterm variability. 72 FR at 54878.
In determining the MACT floor limits, we first determine the floor, which, as explained above, for existing sources is the level achieved in practice by the average of the top 12 percent of existing sources, or the level achieved in practice by the best controlled similar source for new sources. In this rule, EPA is using lowest emissions as the measure of best performance.
We then assess variability of the best performers by using a
statistical formula designed to estimate a MACT floor level that is
equivalent to the average of the best performing sources based on
future compliance tests (or calculated inputs in the case of mercury).
Specifically, the MACT floor limit is an upper prediction limit (UPL)
calculated with the Student's ttest using the TINV function in
Microsoft Excel[reg]. The Student's ttest has also been
used in other EPA rulemakings (e.g., NSPS for Hospital/Medical/
Infectious Waste Incinerators, NESHAP for Industrial, Commercial, and
Institutional Boilers and Process Heaters) in accounting for
variability. A prediction interval for a future observation is an
interval that will, with a specified degree of confidence, contain the
next (or some other prespecified) randomly selected observation from a
population. In other words, the prediction interval estimates what the
upper bound of future values will be, based upon present or past background samples taken. The UPL
consequently represents the value which we can expect the mean of future observations (3run average for HCl, 30day average for mercury, PM, HCl (sources not having wet scrubbers or otherwise electing CEM based compliance), and THC) to fall below within a specified level of confidence, based upon the results of an independent sample from the same population. In other words, if we were to randomly select a future test condition from any of these sources (i.e., average of 3 runs or 30day average) we can be 99 percent confident that the reported level will fall at or below the UPL value. Use of the UPL is appropriate in this rulemaking because it sets a limit any single or future source can meet based on the performance of members of the MACT pool.
This formula uses a pooled variance (in the s \2\ term) that encompasses all the datapoint to datapoint variability of the best performing sources comprising the MACT floor pool for each HAP. Where variability was calculated using the UPL statistical approach (i.e., for the Hg, HCl, and PM standards), we used the average (or sample mean) and sample standard deviation, which are two statistical measures calculated from the data distributions for mercury, HCl, and PM. The average is a central value of a data set, and the standard deviation is the common measure of the dispersion of the data set around the average. We describe in detail in the preamble sections on mercury, HCl and PM and in the memorandum ``Development of the MACT Floors for the Final NESHAP for Portland Cement'', August 6, 2010'' how these averages were developed. We note here that the methodology accounts for both shortterm and longterm variability and encompasses runtorun and testtotest variability. The formula also applies differently depending on how the underlying data set is distributed. To this end, EPA carefully evaluated the data sets for each HAP to ascertain whether the data were normally distributed, or distributed in some other manner (i.e., log normally). After applying standard and rigorous statistical tests (involving the degree of ``skewness'' of the data), we determined that the distributions for mercury and particulate matter were approximately a normal distribution, which in turn determined the final form of the UPL equation. See Floor Calculations for Final Portland Cement NESHAP, August 6, 2010; see also 75 FR at 3201920.
EPA was able to reasonably calculate variability for the THC and HCl standards without needing to use predictive statistics. Specifically, the data set for THC contains a sufficient number of observations to estimate the variability without the need of any type of statistical intervals (no UPL needed to be calculated). For HCl, although EPA applied the UPL formula in developing the HCl standard, the key issue for the HCl data set is the HCl analytic method's detection limit, which ultimately dictated the level of the standard.
At proposal we adopted a form of the UPL equation that has been
used in a previous rulemaking. 69 FR 21233 April 20, 2004. Commenters
stated correctly that there was an error in the equation used at
proposal. As a result of these comments, EPA corrected the formula in
the final rule. The UPL used in the final rule is calculated by: [GRAPHIC] [TIFF OMITTED] TR09SE10.000
x = the mean of the sample data set
n = the number of test runs
m = the number of test runs in the compliance average
s\2\ = observed variance
t = student t distribution statistic
This calculation was performed using the following Excel functions: Normal distribution: 99 percent UPL = AVERAGE(Test Runs in Top 12percent) + [STDEV(Test Runs in Top 12percent) x TINV(2 x probability, n1 degrees of freedom)*SQRT((1/n)+(1/m))], for a onetailed tvalue, probability of 0.01, and sample size of n
This is the same UPL equation that EPA used in more recent rulemakings. See 75 FR 32020 (June 4, 2010) and 75 FR 31905 (June 4, 2010). The value of ``m'' denotes the number of future observations, and it is used to calculate an estimate of the variance of the average of m future observations. For example, if 30day averages are used to determine compliance (m=30), the amount of variability in the 30day average is much lower than the variability of the daily measurements in the data base, which results in a lower UPL for the 30day average.
As an illustration of the effects that correcting the UPL had on the emission limits, we calculated the UPLs for mercury and PM using the proposal version of the UPL formula, and the version used in this final rule. The results of these calculations are presented in Table 1. Both calculated limits are about 20 percent lower when the corrected UPL formula is used.
Table 1Comparison Emission Limits Calculated Using Proposal UPL
Formula Versus Corrected UPL Formula for Existing Sources
(uncorrected UPL (corrected UPL
Mercury, (lb/MM tons feed) [lb/ 29.6 [48.8] 22.5 [37.1] MM tons clinker]...............
PM (lb/ton clinker)............. 0.05 0.04 b. Ramifications of EPA Statistical Approach
A number of commenters maintained that this final rule raises the
(perceived) quandry voiced by Judge Williams in his concurring opinion
in Brick MACT where an achieved level of performance for purposes of
CAA section 112(d)(3) results in a standard which is unachievable under
CAA section 112(d)(2) because it is too costly or not costeffective.
Brick MACT, 479 F. 3d at 88485. EPA is of course mindful of the
repeated admonitions (with accompanying vacaturs and remands) from the
DC Circuit that MACT floors must reflect achieved performance, that HAP
content of process inputs (raw materials and fuels) must be accounted
for in ascertaining sources' performance, and that costs cannot be
considered by EPA in ascertaining the level of the MACT floor. See,
e.g., Brick MACT, 479 F. 3d at 88081, 88283; NRDC v. EPA, 489 F. 3d
1364, 1376 (DC Cir. 2007) (``Plywood MACT''); see also Cement Kiln
Recycling Coalition v. EPA, 255 F. 3d 855, 86162 (DC Cir. 2001)
(``achievability'' requirement of CAA section 112(d)(2) cannot override
the requirement that floors be calculated on the basis of what best
performers actually achieved). EPA is also mindful of the need to
account for sources' variability (both due to control device [[Page 54976]]
performance and variability in inputs) in assessing sources' performance when developing technologybased standards. See, e.g., Mossville Environmental Action Now v. EPA, 370 F. 3d 1232, 1242 (DC Cir. 2004); National Lime I, 627 F. 2d 416,43334(DC Cir. 1980). EPA has carefully developed data for each standard, assessing both technological controls and HAP inputs in doing so. For mercury, EPA used the pooled variance from all of the best performing kilns in the MACT floor pool in order to fully assess these kilns' intraquarry and other variable mercury levels. EPA also used pooled variance to assess the variability of HCl and PM emissions for the MACT floor pool kilns. See 70 FR at 59438 (Oct. 12, 2005) (explaining when use of such pooled variances can be reasonable). EPA has also adopted 30day averaging periods for all of the standards, further allowing short term fluctuations to be averaged out over the 30day period.
The result are floors which reasonably estimate the performance over time of the best performing sources, as do the standards based on those floors. It is true that many sources will need to install controls to meet these standards, and that these controls have significant costs (although EPA estimates that the rule's costs are substantially outweighed by its benefits). See Section VI below. This is part of the expected MACT process where, by definition, the averaged performance of the very best performers sets the minimum level of the standard. The Agency believes that it has followed the statute and applicable case law in developing its floor methodology.
Industry commenters nonetheless maintained that EPA had not
properly accounted for variability of the best performing sources
because not even these sources can meet the standards which are
predicated on their own performance without adding controls. This
contention lacks a basis in the record. For mercury, all performers in
the MACT floor poolnot just those with emissions below the average of
the best performers meet the promulgated standard (highest 30day
average in MACT pool is 41.63 lb/MM tons clinker; the standard is 55
lb/MM tons clinker (30day average). In addition, several additional
kilns, which are not in the pool of best performers, meet the
standards. For THC, all kilns in the pool of best performers meet the
promulgated standard (highest 30day average in MACT pool is 5.68 ppmv;
the standard is 24 ppmv). In addition, seven additional kilns which are
not in the pool of best performers meet the standards. Indeed, nine of
the 11 kilns for which EPA has CEM data are meeting the promulgated
standards for THC. For PM, all six kilns in the MACT pool as well as
twelve kilns overall meet the promulgated 30day standard even though
the measurements in the data base are stack tests (i.e., unlike for
mercury and THC, these are not averaged values).\9\ Virtually all kilns
in the MACT floor pool are meeting the HCl standard, although this is
largely the result of setting the standard at a level reflecting analytic method quantitation limits.
\9\ Development of The MACT Floors For The Final NESHAP For Portland Cement. August 6, 2010.
Commenters presented virtually no quantified data that floor plants
are unable to meet the standards. See National Association of Metal
Finishers v. EPA, 719 F. 2d 624, 649 (3d Cir. 1983) (unquantified
assertions are entitled to little if any weight). Rather, their
comments (comment 2845 at Table 1, echoed by many other industry
commenters) provided narrative descriptions purporting to demonstrate
that floor plants would not be able to achieve the standards.\10\ In
those instances where commenters provided actual data on these plants'
performance, EPA took the information into account in developing the
final standards. Indeed, EPA adjusted all of the standards based on
actual data presented. However, EPA is not willing to act on pure
supposition and conjecture regarding variability, particularly in the
face of record information indicating that not only all floor plants
but a number of additional plants are already meeting the promulgated standards.
\10\ For example, the commenter asserted, without providing support, that for the floor kilns the standards were ``achieved in practice, but not under foreseeable operations''; ``achieved in practice based on limited stack tests''; ``data shows that proposed standard was not achieved in practice when malfunction emission [sic] are included in compliance determination'' (although no such data were provided to EPA).
c. Mercury Limits for Kilns
i. Floor Determination. We proposed mercury emissions limits of 43 lb/million (MM) tons clinker for existing sources and 14 lb/MM tons clinker for new sources. The proposed floor was based on 30 days of data on all kiln inputs for 89 kilns. See 74 FR at 2114243. For all kilns but the five equipped with wet scrubbers, emissions were assumed to equal the total mass of mercury fed to each kiln. Scrubberequipped kilns were considered to emit all mercury minus an assumed amount representing the average performance of the wet scrubbers. For kilns that waste cement kiln dust (CKD), the mercury component of the CKD was subtracted from inputs to calculate emissions. Id. By conducting a total mass balance for mercury and then assuming that all mercury inputted is emitted (minus conservatively estimated removals for scrubber usage and dust wastage), EPA made a near worst case assumption as to kilns' mercury emission levels. The kilns were then ranked from best to worst based on the extrapolated mercury emissions, normalized to clinker production. EPA further proposed that no beyond the floor standard was appropriate for either existing or new sources. Id. at 21149.
Since proposal we received updated data on certain kilns' raw
materials usage and mercury content \11\ and used that data to revise
our average mercury emissions estimates from the best performing kilns
at proposal.\12\ We have also revised upward the floor kilns' projected
emissions based on their reasonably estimated intraquarry variability
(explained further below). As a result, estimated emissions from these
kilns increased, and one of the kilns in the group of sources used to
set the existing source floor is no longer one of the best performing
kilns. At proposal, the average mercury emissions of the top 12 percent
of the kilns was 27.4 pounds per million (lb/MM) tons clinker, and the
average emissions of the best performing source were 13.4 lb/MM ton
clinker. After revising our mercury emissions estimates, the averages
were 32 and 14 lb/MM tons clinker, respectively, as shown in Table 2.
\11\ See Portland Cement Association Comments on the NESHAP
Proposed Rule (Docket Number: EPAHQOAR20020051) (September 4, 2009) at pp. 3135.
\12\ Development of The MACT Floors For The Final NESHAP For Portland Cement, August 6, 2010.
Table 2Mercury MACT Floor
Mercury emissions Kiln code (lb/MM ton feed) 1589............................................... 8.48 1650............................................... 9.53 1315............................................... 15.26 1302............................................... 15.28 1248............................................... 16.63 1259............................................... 21.33 1286............................................... 22.65 1594............................................... 25.23 1435............................................... 25.51 1484............................................... 25.51 1364............................................... 25.91 MACTExisting Kilns
Average: lb/MM tons feed (lb/MM tons clinker)...... 19.21 (31.7) Total variance..................................... 272.3 [[Page 54977]]
FOR FURTHER INFORMATION CONTACT
Mr. Keith Barnett; Office of Air Quality Planning and Standards; Sector Policies and Programs Division, Metals and Minerals Group (D24302); Environmental Protection Agency; Research Triangle Park, NC 27711; telephone number: (919) 5415605; fax number: (919) 5415450; email address: email@example.com.