	[6560-50-P]
                        ENVIRONMENTAL PROTECTION AGENCY
                                40 CFR Part 63
                     [EPA-HQ-OAR-2002-0051; FRL-        ]
RIN 2060-AO15 
National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing Industry
                                       
AGENCY:  Environmental Protection Agency (EPA).
ACTION:  Proposed rule.
SUMMARY:  EPA is proposing amendments to the current National Emission Standards for Hazardous Air Pollutants (NESHAP) from the Portland Cement Manufacturing Industry.  These proposed amendments would add or revise, as applicable, emission limits for mercury, total hydrocarbons (THC), and particulate matter (PM) from kilns and in-line kiln/raw mills located at a major or an area source, and hydrochloric acid (HCl) from kilns and in-line kiln/raw mills located at major sources.  These proposed amendments also would remove four provisions in the current regulation: the operating limit for the average hourly recycle rate for cement kiln dust, and the requirement that cement kilns only use certain type of utility boiler fly ash.  They would also remove the opacity limits for kilns and clinker coolers and the 50 parts per million volume dry (ppmvd) THC emission limit for new greenfield sources.
        
DATES:  Comments must be received on or before [INSERT DATE 60 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. If any one contacts EPA by [INSERT DATE 10 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER] requesting to speak at a public hearing, EPA will hold a public hearing on [INSERT DATE 15 DAYS AFTER PUBLICATION OF THIS PROPOSED RULE IN THE FEDERAL REGISTER].  Under the Paperwork Reduction Act, comments on the information collection provisions are best assured of having full effect if the Office of Management and Budget (OMB) receives a copy of your comments  on or before [INSERT DATE 30 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER].
ADDRESSES:  Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2002-0051, by one of the following methods: 
       http://www.regulations.gov:  Follow the on-line instructions for submitting comments.
       E-mail:  a-and-r-docket@epa.gov. 
       Fax:  (202) 566-9744.
       Mail:  U.S. Postal Service, send comments to:  EPA Docket Center (6102T), National Emission Standards for Hazardous Air Pollutant From the Portland Cement Manufacturing Industry Docket, Docket ID No. EPA-HQ-OAR-2002-0051, 1200 Pennsylvania Ave., NW, Washington, DC 20460.  Please include a total of two copies.  In addition, please mail a copy of your comments on the information collection provisions to the Office of Information and Regulatory Affairs, Office of Management and Budget (OMB), Attn:  Desk Officer for EPA, 725 17th St., NW, Washington, DC 20503.
       Hand Delivery:  In person or by courier, deliver comments to:  EPA Docket Center (6102T), Standards of Performance (NSPS) for Portland Cement Plants Docket, Docket ID No. EPA-HQ-OAR-2007-0877, EPA West, Room 3334, 1301 Constitution Avenue, NW, Washington, DC 20004.  Such deliveries are only accepted during the Docket's normal hours of operation, and special arrangements should be made for deliveries of boxed information.  Please include a total of two copies.
      Instructions:  Direct your comments to Docket ID No. EPA-HQ-OAR-2002-0051.  EPA's policy is that all comments received will be included in the public docket without change and may be made available online at www.regulations.gov, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute.  Do not submit information that you consider to be CBI or otherwise protected through www.regulations.gov or e-mail.  The www.regulations.gov website is an "anonymous access" system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment.  If you send an e-mail comment directly to EPA without going through www.regulations.gov, your e-mail address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet.  If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit.  If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment.  Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses.
      Docket:  All documents in the docket are listed in the www.regulations.gov index.  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, will be publicly available only in hard copy.  Publicly available docket materials are available either electronically in www.regulations.gov or in hard copy at the EPA Docket Center, National Emission Standards for Hazardous Air Pollutants from the Portland Cement Manufacturing Industry Docket, 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 Docket Center is (202) 566-1742.
FOR FURTHER INFORMATION CONTACT:  Mr. Keith Barnett, Office of Air Quality Planning and Standards, Sector Policies and Programs Division, Metals and Minerals Group (D243-02), Environmental Protection Agency, Research Triangle Park, NC 27711, telephone number:  (919) 541-5605; fax number:  (919) 541-5450; e-mail address:  barnett.keith@epa.gov.
SUPPLEMENTARY INFORMATION:
	The information presented in this preamble is organized as follows:
I.  General Information
A.  Does this action apply to me?
B.  What should I consider as I prepare my comments to EPA?
C.  Where can I get a copy of this document?
D.  When would a public hearing occur?
II.  Background Information
A.  What is the statutory authority for these proposed amendments? 
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. Summary of Proposed Amendments to Subpart LLL
   A. Emissions Limits
   B. Operating Limits
   C. Testing and Monitoring Requirements
IV.  Rationale for Proposed Amendments to Subpart LLL
A.  MACT Floor Determination Procedure for all Pollutants
B.  Determination of MACT for Mercury Emissions from Major and Area Sources
C.  Determination of MACT for THC Emissions from Major and Area Sources
D.  Determination of MACT for HCl Emissions from Major Sources
E.  Determination of MACT for PM Emissions from Major and Area Sources
F.  Selection of Compliance Provisions
G.  Selection of Compliance Dates
H.  Discussion of EPA's Sector Based Approach for Cement Manufacturing
I.  Other Changes and Areas Where We are Requesting Comment	
V.  Summary of Comments and Responses on Notice of
Reconsideration and EPA Final Action in Response to Remand
A.  Petition to Withdraw Final Standards
B.  Petition to Reconsider Final Standards
C.  New Source MACT for Mercury Emissions and Related  
Requirements
D.  New Source MACT for THC Emissions and Related
Requirements
E.  Cement Kiln Dust Requirements
F.  Fly Ash Requirements
G.  Compliance Dates for Cement Kiln Dust and Fly Ash Provisions
H.  Research and Technology
VI.  Summary of Cost, Environmental, Energy, and Economic 
Impacts of Proposed Amendments
A.  What are the affected sources?
B.  How are the impacts for this proposal evaluated?
C.  What are the air quality impacts?
D.  What are the water quality impacts?
E.  What are the solid waste impacts?
F.  What are the secondary impacts?
G.  What are the energy impacts?
H.  What are the cost impacts?
I.  What are the economic impacts? 
J.  What are the benefits?
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 Low-
Income Populations

I.  General Information
A.  Does this action apply to me?
	Categories and entities potentially regulated by this proposed rule include:  
                                   Category
                                NAICS   code[1]
                        Examples of regulated entities
Industry....
                                    327310
Portland cement plants
Federal government...
                                       
Not affected.
State/local/tribal government...
                                       
Portland cement 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 would be regulated by this proposed action, you should examine the applicability criteria in 40 CFR 63.1340 (subpart LLL).  If you have any questions regarding the applicability of this proposed action to a particular entity, contact the person listed in the preceding FOR FURTHER INFORMATION CONTACT section.
B.  What should I consider as I prepare my comments to EPA?
	Do not submit information containing CBI to EPA through www.regulations.gov or e-mail.  Send or deliver information identified as CBI only to the following address:  Roberto Morales, OAQPS Document Control Officer (C404-02), Office of Air Quality Planning and Standards, Environmental Protection Agency, Research Triangle Park, NC 27711, Attention Docket ID No. EPA-HQ-OAR-2002-0051.  Clearly mark the part or all of the information that you claim to be CBI.  For CBI information in a disk or CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM as CBI and then identify electronically within the disk or CD-ROM the specific information that is claimed as CBI.  In addition to one complete version of the comment that includes information claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket.  Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2.
C.  Where can I get a copy of this document?
	In addition to being available in the docket, an electronic copy of this proposed action is available on the Worldwide Web (WWW) through the Technology Transfer Network (TTN).  Following signature, a copy of this proposed 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.
D.  When would a public hearing occur?
	If anyone contacts EPA requesting to speak at a public hearing by [INSERT DATE 10 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER], a public hearing will be held on [INSERT DATE 15 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. HYPERLINK "mailto:garrett.pamela@epa.gov"   Persons interested in presenting oral testimony or inquiring as to whether a public hearing is to be held should contact Mr. Keith Barnett, listed in the FOR FURTHER INFORMATION CONTACT section, at least 2 days in advance of the hearing.
	
II.  Background Information
A.  What is the statutory authority for these proposed amendments? 
      Section 112(d) of the Clean Air Act (CAA) requires EPA to set emissions standards for Hazardous Air Pollutants (HAP) emitted by major stationary sources based on performance of the maximum achievable control technology (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 5 sources for source categories with less than 30 sources (CAA section 112(d)(3)(A) and (B)).  This level of minimum stringency is called the MACT floor.  For new sources, MACT standards must be at least as stringent as the control level achieved in practice by the best controlled similar source (CAA section 112(d)(3)).  EPA also must consider more stringent "beyond-the-floor" control options.  When considering beyond-the-floor options, EPA must consider not only the maximum degree of reduction in emissions of HAP, but must take into account costs, energy, and nonair environmental impacts when doing so.
      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 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).
      The portland cement source category was listed as a source category for regulation under this 1999 Strategy based on emissions of arsenic, cadmium, beryllium, lead, and polychlorinated biphenyls.  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 rule fulfills the requirement to regulate area source cement kiln emissions of polychlorinated biphenyls (for which THC is a surrogate).  However, EPA did not include requirements for the control of the non-volatile metal HAP (arsenic, cadmium, beryllium, and lead) from area sources in the 1999 rule or in the 2006 amendments.  To fulfill our requirements under section 112(k), EPA is proposing to regulate emissions of these metal HAP from portland cement manufacturing facilities that are area sources (using particulate matter as a surrogate).  In this proposal, EPA is proposing PM standards for area sources based on performance of MACT.  
 	Section 112(c)(6) requires EPA to list, and to regulate under standards established pursuant to section 112(d)(2) or (d)(4), categories of sources accounting for not less than 90 percent of emissions of each of seven specific HAP:  alkylated lead compounds; polycyclic organic matter; hexachlorobenzene; mercury; polychlorinated byphenyls; 2,3,7,8-tetrachlorodibenzofurans; and 2,3,7,8-tetrachloroidibenzo-p-dioxin.  Standards established under CAA 112(d)(2) must reflect the performance of MACT.  "Portland cement manufacturing:  non-hazardous waste kilns" is listed as a source category for regulation under section 112(d)(2) pursuant to the section 112(c)(6) requirements due to emissions of polycyclic organic matter, mercury, and dioxin/furans (63 FR 17838, 17848, April 10, 1998); see also 63 FR at 14193 (March 24, 1998) (area source cement kilns' emissions of mercury, dibenzo-p-dioxins and dibenzo-p-furans, polycyclic organic matter, and polychlorinated biphenyls are subject to MACT).
 	
 	 - 
 		
 		
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).  The 1999 final rule established emission limitations for PM as a surrogate for non-volatile HAP metals (major sources only), dioxins/furans, and for greenfield new sources total THC as a surrogate for organic HAP.  These standards were intended to be based on the performance of MACT pursuant to sections 112 (d)(2) and (3).  We did not establish limits for THC for existing sources and non-greenfield 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. 
	Ruling on petitions for review of various environmental groups, the D.C. Circuit held that EPA had erred in failing to establish section 112 (d) standards for mercury, THC (except for greenfield new sources) and hydrochloric acid.  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 (D.C. Cir. 2000).  The court also stated that EPA is obligated to consider other pollution - reducing measures such as process changes and material substitution.  Id. at 634. 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., Sierra Club v. EPA (Brick MACT), 479 F. 3d 875, 882-83      (D.C. Cir. 2007).    
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 national emission standards for these HAP.  The final amendments contain a new source standard for mercury emissions from cement kilns and kilns/in-line raw mills of 41 micrograms per dry standard cubic meter, or alternatively the application of a limestone wet scrubber with a liquid-to-gas 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 mercury-laden 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 worst case operating conditions and exposure assumptions, would emit HCl at levels that would exceed that threshold level, allowing for an ample margin of safety.  	
D.  Reconsideration of EPA Final Action in Response to the Remand  
      At the same time we issued the final amendments, EPA itself determined to reconsider the new source standard for mercury, the existing and new source standard banning cement kiln use of certain mercury-containing 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.  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 mercury-containing 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 support a beyond-the-floor 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 is appropriate to amend the promulgated standards.  
	EPA received comments on the notice of reconsideration from cement plants, energy companies, industry associations, a technical consultant, one State, one environmental group, 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.  We have carefully considered these comments in the development of these proposed amendments.  Section V of this preamble summarizes the comments on the notice of reconsideration and EPA's responses.
	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 D.C. Circuit court issued an opinion  
(Sierra Club v. EPA, 479 F.3d 875 (D.C. Cir. 2007)(Brick MACT)) vacating and remanding section 112(d) MACT standards for the Brick and Structural Clay Ceramics source categories.  Some of the key holdings in that case were:
   * Floors for existing sources must reflect the average emission limitation achieved by the best performing 12 percent of existing sources, not levels EPA considers to be achievable by all sources; 
   *    EPA cannot set floors of "no control."   The Court reiterated its prior holdings, including National Lime Ass'n, confirming that EPA must set floor standards for all HAP emitted by the major source, including those HAP that are not controlled by at-the-stack control devices
   *    EPA cannot ignore non-technology factors that reduce HAP emissions.  Specifically, the Court held that "EPA's decision to base floors exclusively on technology even though non-technology factors affect emissions violates the Act." 
Based on 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 unintended is not a legal basis for excluding the source's performance from consideration.  National Lime Ass'n, 233 F. 3d at 640.
	The Brick MACT decision also stated 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.	
	The majority opinion in the Brick MACT case does not address the possibility of subcategorization to address differences in the HAP content of raw materials.  However, Judge William's concurrence opined that EPA's ability to create subcategories for sources of different classes, size, or type (section 112 (d)(1)) may provide a means out of the seeming paradox of floor standards being achieved in practice yet be unachievable where they reflect differences in raw material HAP levels to which other sources may lack access.  Id.at 884-85.
	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 is also relevant to this proposal.  In Sierra Club v. EPA, 551 F. 3d 1019 (D.C. Cir. 2008) the court vacated the regulations contained in the General Provisions which exempt major sources from MACT standards during periods of startup, shutdown and malfunction (SSM)).  The regulations (in 40 C.F.R. 63.6(f)(1) and 63.6(h)(1)) provided that sources need not comply with the relevant 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 Portland Cement NESHAP does not contain specific provisions covering operation during SSM operating modes; rather it references the now-vacated rules in the General Provisions.  As a result of the court decision vacating those general provisions, we are required to address them in this rulemaking.  Discussion of this issue may be found in Section IV.G.
III. Summary of Proposed Amendments to Subpart LLL 
	This section presents the proposed amendments to the Portland Cement NESHAP.  In the section presenting the amended rule language, there is some language that it not amendatory, but is presented for the reader's convenience.  We are not reopening or otherwise considering unchanged rule language presented for the reader's convenience, and will not accept comments on such language. 

A.  Emissions Limits

	We are proposing the following new emission limits in this action.
Kilns and In-line Kiln/Raw mills
      Mercury.  For cement kilns or in-line kilns/raw mills an emissions limit of 43 lb/million(MM) tons clinker for existing sources and 14 lb/MM tons clinker for new sources.  Both proposed limits are based on an averaging period of 30 days.
      	THC.  For cement kilns or in-line kilns/raw mills an emissions limit of 7 parts per million by volume (ppmv) for existing sources and 6 ppmvd for new sources, measured dry as propane and corrected to 7 percent oxygen, measured on a 30 day average in each case.  Because the proposed existing source standard would be more stringent than the new source standard of 50 ppmv contained in the 1999 final rule for greenfield new sources, we are also proposing to remove the 50 ppmv standard.
      As an alternative to the THC standard, we are proposing that the cement kilns or in-line kilns/raw mills can meet a standard of 2 ppmv total combined organic HAP for existing sources or 1 ppmv total organic HAP combined for new sources, measured dry and corrected to 7 percent oxygen.  The alternative standard would be based on organic HAP emission testing that would establish a site specific THC limit that would demonstrate compliance with the total organic HAP limit.  The site specific THC limit would be measured as a 30 day rolling average.  	
      PM.  For cement kilns or cement kilns/in-line raw mills an emissions limit of 0.085 pounds per ton (lb/ton) clinker for existing sources and 0.080 lb/tons clinker for new sources.  Kilns and kiln/in-line raw mills where the clinker cooler gas is combined with the kiln exhaust and sent to a single control device for energy efficiency purposes (i.e., to extract heat from the clinker cooler exhaust) would be allowed to adjust the PM standard upward based on the relative gas flows from the kiln and the clinker cooler exhaust.
	Opacity.  We are proposing to remove all opacity standards for kilns and clinker coolers because these sources will be required to monitor compliance with the PM emissions limits by more accurate means.  
	Hydrochloric Acid.  For cement kilns or cement kilns/in-line raw mills an emissions limit of 2 ppmv for existing sources and 0.1 ppmv for new sources, measured dry and corrected to 7 percent oxygen.  For facilities that are required to use a continuous emissions monitoring system (CEMS), there would be a 30 day averaging period.
Clinker Coolers
      For clinker coolers a PM emissions limit of 0.085 lb/ton clinker for existing sources and 0.080 lb/tons clinker for new sources.  
Raw Material Dryers
	THC.  For raw materials dryers an emissions limit of 7 ppmv for existing sources and 6 ppmv for new sources, measured dry as propane and corrected to 7 percent oxygen, measured on a 30 day rolling average.  Because the proposed existing source standard would be more stringent than the new source standard of 50 ppmv contained in the 1999 final rule for Greenfield new sources, we are also proposing to remove the 50 ppmv standard.
	As an alternative to the THC standard, the raw material dryer can meet a standard of 2 ppmv total combined organic HAP for existing sources or 1 ppmv total organic HAP combined for new sources, measured dry and corrected to 7 percent oxygen.  The alternative standard would be based on organic HAP emission testing that would establish a site specific THC limit that would demonstrate compliance with the total organic HAP limit.  The site specific THC limit would be measured as a 30 day rolling average.  
B.  Operating Limits
		EPA is proposing to eliminate the restriction on the use of fly ash where the mercury content of the fly ash has been increased through the use of activated carbon.  Given the proposed emission limitation for mercury, whereby kilns or cement kilns/in-line raw mills must continuously meet the mercury emission limits described above (including when using these materials) there does not appear to be a need for such a provision.  For the same reason, EPA is proposing to remove the requirement to maintain the amount of cement kiln dust wasted during testing of a control device, and the provision requiring that kilns remove from the kiln system sufficient amounts of dust so as not to impair product quality.
C. Testing and Monitoring Requirements
	We are proposing the following changes in testing and monitoring requirements:
Kilns and kiln/in-line raw mills would be required to meet the following changed monitoring/testing requirements:
   * CEMS (PS-12A) or sorbent trap monitors (PS-12B) to continuously measure mercury emissions.
   * CEMS meeting the requirement of PS-8A to measure THC emissions for existing sources (new sources are already required to monitor THC with a CEM).  Kilns and kiln/in-line raw mills meeting the organic HAP alternative to the THC limit would still be required to continuously monitor THC, and would also be required to test emissions using EPA Method 320 every five years to identify the organic HAP component of their THC emissions.  
   * Installation and operation of a bag leak detection system to demonstrate compliance with the PM emissions limit.  If electrostatic precipitators (ESP) are used for PM control an ESP predictive model to monitor the performance of ESP controlling PM emissions from kilns would be required.  As an alternative EPA is proposing that sources may use a PM CEMS that meets the requirements of PS-11.  
   * CEMS meeting the requirements of PS-15 would be required to demonstrate compliance with the HCl standard.  If a facility is using a caustic scrubber to meet the standard, EPA Test Method 321 may used in lieu of a CEMS to demonstrate compliance.  The M321 test must be repeated every 5 years. 
      For clinker coolers, EPA is proposing use of a bag leak detection system to demonstrate compliance with the proposed PM emissions limit.  If an ESP is used for PM control on clinker coolers, an ESP predictive model to monitor the performance of ESP controlling PM emissions from kilns would be required.  As an alternative, EPA is proposing that a PM CEMS that meets the requirements of PS-11 may be used.
	Raw material dryers that are existing sources would be required to install and operate CEMS meeting the requirement of PS-8A to measure THC emissions.  (New sources are already required to monitor THC with a CEM).  Raw material dryers meeting the organic HAP alternative to the THC limit would still be required to continuously monitor THC, and would also be required to test emissions using EPA Method 320 every five years to identify the organic HAP component of their THC emissions.  
	
IV.  Rationale for Proposed Amendments to Subpart LLL

A.  MACT Floor Determination Procedure for all Pollutants

      The MACT floor limits for each of the HAP and HAP surrogates (mercury, total hydrocarbons, HCl, and particulate matter) are calculated based on the performance of the lowest emitting (best performing) sources in each of the MACT pool sources.  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 performing source.  The MACT floor limit is calculated from a formula that is a modified prediction limit, designed to estimate a MACT floor level that is achievable by the average of the best performing sources (i.e., those in the MACT pool) if the best performing sources were able to replicate the compliance tests in our data base.  Specifically, the MACT floor limit is an upper prediction limit (UPL) calculated from:
      
                              UPL = xp + t * (VT)[0.5]
where
Xp = average of the best performing MACT pool sources,
t = Student's t-factor evaluated at 99 percent confidence, and 
vT = total variance determined as the sum of the within-source variance and the between-source variance.

The between-source variance is the variance of the average of the best performing source averages.  The within-source variance is the variance of the MACT source average considering "m" number of future individual test runs used to make up the average to determine compliance.  The value of "m" is used to reduce the variability to account for the lower variability when averaging of individual runs is used to determine compliance in the future.  For example, if 30-day averages are used to determine compliance (m=30), the variability based 30-day averages is much lower than the variability of the daily measurements in the data base, which results in a lower UPL for the 30-day average.
B.  Determination of MACT for Mercury Emissions from Major and Area Sources
      The limits for existing and new sources we are proposing here apply to both area and major new sources.  These limits would also apply to area sources consistent with section 112(c)(6) of the Act, as EPA determined in the original rule. See 63 FR at 14193.
1.  Floor Determination
Selection of existing source floor
      Cement kilns' emissions of mercury reflect exclusively the amounts of mercury in each kilns' feedstock and fuel inputs.  The amounts of mercury in these inputs vary by site.  In many cases the majority of the mercury emissions result from the mercury present as a trace contaminant in the limestone, which typically comes from a propriety quarry located adjacent to the plant.  Limestone is the single largest input, by mass, to a cement kiln's total mass input, typically making up 80 percent of that loading.  Mercury is also found as a trace contaminant in the other inputs to the kiln such as the additives that supply the required silica, alumina, and iron.  Mercury is also present in the coal and petroleum coke typically used to fuel cement kilns.  
      Mercury levels in limestone can vary significantly, both within a single quarry and between quarries. Since quarries are proprietary (one facility cannot access another's limestone), this variability is inherent and site-specific.  Mercury levels in additives and fuels likewise vary significantly, although mercury emissions attributable to limestone often dominate the total due to the larger amount of mass input contributed by limestone (see further discussion of this issue at Other Options EPA considered in Setting Floor for Mercury below).  
      The first step in establishing a MACT standard is to determine the MACT floor.  A necessary step in doing so is determining the amount of HAP emitted.  In the case of mercury emitted by cement kilns, this is not necessarily a straightforward undertaking.  Single stack measurements represent a snapshot in time of a source's emissions, always raising questions of how representative such emissions are of the source's emissions over time.  This problem is compounded in the case of cement kilns, because cement kilns do not emit mercury uniformly.  For all kilns, the mercury content of the feed and fuels varies significantly from day-to-day and even hour-to-hour.  For modern preheater and preheater/precalciner kilns this problem is compounded because these kiln have in-line raw mills.  With in-line raw mills, mercury is captured in the ground raw meal in the in-line raw mill and this raw meal (containing mercury) is returned as feed to the kiln.  Mercury emissions may remain low during such recycling operations.  However, as part of normal operation of a kiln raw mills must be periodically shut down for maintenance, and mercury-containing exhaust gases from the kiln are then bypassed directly to the main APCD device resulting in significantly increased mercury emissions at the stack.  The result is that at any given time, mercury emissions from such cement kilns are either low or high, but rarely in equilibrium, so that single stack tests are likely to either underestimate or overestimate cement kilns' performance over time.  Put another way, we believe that single short term stack test data (typically a few hours) are probably not indicative of long term emissions performance, and so are not the best indicator of performance over time.  With these facts in mind, we carefully considered alternatives other than use of single short-term stack test results to quantify kilns' performance for mercury.  
      An alternative to short term stack test data would be to use mercury continuous monitoring data over a longer time period.  Because no cement kilns in the United States have continuous mercury monitors, this option was not available.  However, mercury is an element, and can neither be created nor destroyed in a cement kiln.  Therefore, all the mercury that enters a kiln has to leave the kiln in some fashion.  The available data indicate that almost no mercury leaves the kiln as part of the clinker (product).  Therefore, over the long term all the mercury leaves the kiln as a stack emission with three exceptions:
1. If instead of returning all particulate captured in the particulate control device to the kiln, the source instead removes some of it from the circuit entirely, i.e., the kiln wastes some cement kiln dust (CKD); or 
2. The kiln is equipped with an alkali bypass, which means all CKD captured in the alkali bypass PM control is wasted, and/or; 
3. If the kiln has a wet scrubber (usually for SO2 control), the scrubber will remove some mercury which will end up in the gypsum generated by the scrubber.
      Based on these facts we determined the most accurate method available to us to determine long term mercury emissions performance was to do a total mass balance.  We did so by obtaining data on all the kiln mercury inputs (i.e., all raw materials and all fuels) for a large group of kilns, and assuming all mercury that enters the kiln is emitted with the three exceptions noted above.  Pursuant to letters mandating data gathering, issued under the authority of section 114, we obtained 30 days of daily data on kiln mercury concentrations in each individual raw material, fuel, and CKD for 89 kilns, along with annual mass inputs and the amount of material collected in the PM control device (or alkali PM control device) that is wasted rather than returned to the kiln.       
      These data were submitted to EPA as daily concentrations for the inputs, i.e., samples of all inputs were taken daily and analyzed daily for their mercury content.  We took the daily averages, calculated a mean concentration, and multiplied the mean concentration by annual materials use to calculate an annual mercury emission for each of the 89 kilns.  If the facility wasted CKD, we subtracted out the annual mercury that left the system in the CKD.  If the facility had a wet scrubber (the only control device currently in use among the sampled kilns with any substantial mercury capture efficiency), we subtracted out the annual mercury attributable to use of the scrubber.  There are five cement kilns using wet scrubbers and EPA has removal efficiencies for four of these kilns (based on inlet/outlet testing conducted at EPA's request concurrent with the input sampling).  We attributed a removal efficiency for the fifth kiln based on the average removal efficiency of the other four kilns. 
      
      For each kiln, we took this (calculated) annual emission and then divided by total inputs to calculate an average emission factor  -  the average projected emission rate for each kiln.  We then ranked each kiln from lowest average emission factor to highest.  The resulting emissions factors for 87 of the 89 ranged (relatively continuously) from 7 to 300 pounds of mercury per million tons of feed.  Two kilns showed considerably higher numbers, approximately 1200 and 2000 pounds per ton of feed.  These two facilities have atypically high mercury contents in the limestone in their proprietary quarries which are the most significant contributors to the high mercury emissions.  
      Based on these data and ranking methodology, the existing source MACT floor would be the average of the lowest emitting 12 percent of the kilns for which we have data, which would be the 11 kilns with lowest emissions (as calculated), shown in Table 1. 
                         Table 1.  Mercury MACT Floor
                                   Kiln code
                      Mercury emissions (lb/MM ton feed)
                                     1233
                                     7.14
                                     1650
                                     10.83
                                     1589
                                     11.11
                                     1302
                                     14.51
                                     1259
                                     15.16
                                     1315
                                     15.41
                                     1248
                                     18.09
                                     1286
                                     21.12
                                     1435
                                     22.89
                                     1484
                                     22.89
                                     1364
                                     23.92
                             MACT - Existing Kilns
Average:  lb/MM tons feed (lb/MM tons clinker)
                                  16.6 (27.4)
 
                            Variability (t*vT[0.5])
                                     9.52
 
99th percentile:  lb/MM tons feed (lb/MM tons clinker)
                                    26 (43)
 
                               MACT - New Kilns
Average:  lb/MM tons feed (lb/MM tons clinker)
                                  7.1 (11.8)
 
                            Variability (t*vT[0.5])
                                      1.3
 
99th percentile:  lb/MM tons feed (lb/MM tons clinker)
                                    8.4(14)
 

       The average emission rate for these kilns is 16.6 pounds per million tons (lb/MM) tons feed (27.4 lb/MM tons clinker).  The emission rate of the single lowest emitting source is 7.1 lb/MM tons feed (11.8 lb/MM tons clinker).  
      As previously discussed above, we account for variability in setting floors, not only because variability is an element of performance, but because it is reasonable to assess best performance over time.  Here, for example, we know that the 11 lowest emitting kiln emission estimates are averages, and that the actual emissions will vary over time.  If we do not account for this variability, we would expect that even the kilns that perform better than the floor on average would potentially exceed the floor emission levels a significant part of the time  -- meaning that their performance was assessed incorrectly in the first instance.
      For the 11 lowest emitting kilns, we calculated a daily emission rate using the daily concentration values and annual materials inputs divided by each kiln's operating days.  The results are shown in Table 1 and represent the average performance of each kiln over the 30-day period.  We then calculated the average performance of the 11 lowest emitting kilns (17 lb/MM tons of feed) and the variances of the daily emission rates for each kiln which is a direct measure of the variability of the data set.  This variability includes the day-to-day variability in the total mercury input to each kiln and variability of the sampling and analysis methods over the 30-day period, and it includes the variability resulting form site-to-site differences for the 11 lowest emitters.  We calculated the MACT floor (26 lb/MM tons feed) based on the UPL (upper 99[th] percentile) as described earlier from the average performance of the 11 lowest emitting kilns, Students t-factor, and the total variability, which was adjusted to account for the lower variability when using 30 day averages.  
      EPA also has some information which tends to corroborate the variability factor used to calculate the floor for mercury.  These data are not emissions data; they are data on the total mercury content of feed materials over periods of 12 months or longer.  Because mercury emissions directly correlate with mercury content of feed materials, we believe an analysis of the variability of the feed materials is an accurate surrogate for the variability of mercury emissions over time.  These long term data are from multiple kilns from a single company that are not ranked among the lowest emitters, but are nonetheless germane as a crosscheck on variability of mercury content of feed materials (including whether 30 days of sampling, coupled with statistically derived variability of that data set and a 99[th] percentile, adequately measures that variability).  
      One way of comparing the variability among different data sets with different average values is to calculate the relative standard deviations (RSD), which is the standard deviation divided by the mean.  If the RSD are comparable, then one can conclude that the variability among the data sets is comparable.  The results of such an analysis are given in Table 2 below.  The long term data represent long term averages of feed material mercury content based on 12 months of data or more, whereas the MACT data sets are for 30 consecutive days of data.  The RSD of the long term data are comparable to and within the same range as the RSD for the MACT data.  This comparison suggests our method of calculating variability in the proposed floor by using variances/99[th] percentile UPL appears to adequately encompass sources' long-term variability.
Table 2.  Comparison of Long-Term Kiln Feed Mercury Concentration at Essroc Plants with the Feed Mercury Concentration Data for the MACT Floor Kilns
 
PPM Hg in Feed
 
 
Kiln
Mean
Standard Deviation
RSD
Source
1248[a]
                                     0.021
                                     0.002
                                     0.10
MACT floor kiln[b]
1589[a]
                                     0.021
                                     0.002
                                     0.10
MACT floor kiln
1435
                                     0.012
                                     0.002
                                     0.16
MACT floor kiln
1484
                                     0.012
                                     0.002
                                     0.16
MACT floor kiln
1233
                                     0.011
                                     0.002
                                     0.16
MACT floor kiln
1650
                                     0.025
                                     0.005
                                     0.22
MACT floor kiln
Speed
                                     0.055
                                     0.016
                                     0.29
Essroc[c]
1286
                                     0.006
                                     0.002
                                     0.32
MACT floor kiln
1364
                                     0.006
                                     0.002
                                     0.32
MACT floor kiln
San Juan 
                                     0.322
                                     0.108
                                     0.34
Essroc
Bessemer
                                     0.021
                                     0.007
                                     0.35
Essroc
Logansport
                                     0.022
                                     0.008
                                     0.37
Essroc
Naz III
                                     0.016
                                     0.010
                                     0.61
Essroc
Naz I
                                     2.974
                                     1.838
                                     0.62
Essroc
1302
                                     0.006
                                     0.004
                                     0.68
MACT floor kiln
1315
                                     0.006
                                     0.004
                                     0.68
MACT floor kiln
Martinsburg
                                     0.023
                                     0.017
                                     0.89
Essroc
1259
                                     0.008
                                     0.007
                                     0.89
MACT floor kiln
Picton
                                     0.075
                                     0.078
                                     1.05
Essroc
[a] Same feed sample applied to multiple kilns at the plant
[b] MACT floor kilns' variabilities are all based on approximately 30 days of data
c Essroc kiln's variabilities are all based on 12 months to three years of data.

	We are proposing to express the floor as a 30 day rolling average.  There are two reasons for doing so.  First, as explained earlier, daily variations in mercury emissions at the stack for all kilns with in-line raw mills is greater than daily variability of mercury levels in inputs.  This is because mercury is emitted in high concentrations during mill-off conditions, but in lower concentrations when mercury is recycled to the kiln via the raw mill (`mill-on').  We believe that 30 days is the minimum averaging time that allows for this mill-on/mill-off variation.
	Second, a 30 day rolling average is tied to our proposed implementation regime, which in turn is based on the means by which the data used to generate the standard were developed.  As explained above, the proposed floor reflects 30 days of sampling which are averaged, corresponding to the proposed 30-day averaging period.  EPA is also proposing to monitor compliance by means of daily monitoring via a CEMS, so that the proposed implementation regime likewise mirrors the means by which the underlying data were gathered and used in developing the standard. 
      Critical to this variability calculation is the assumption that EPA is adequately accounting for variable mercury content in kiln inputs.  As noted, we did so based on 30-days of continuous sampling of all kiln inputs, plus use of a further statistical variability factor (based on that data set) and use of the 99[th] percentile UPL.  The 30-day averaging time in the standard is a further means of accounting for variability, and accords with the data and methodology EPA used to develop the floor level. 
      We solicit comment on the accuracy of this analysis.  The most pertinent information, would of course be further sampling data of inputs to specific kilns (especially data from sampling over a longer period than 30-days).  EPA also expressly solicits further information regarding potential substitutability of non-limestone kilns inputs and whether kilns actually utilize inputs other than those reflected in the 30-day sampling effort comprising EPA's present data base for mercury, and if so, what mercury levels are in these inputs.
Selection of new source floor
	Based on Table 1, the average associated with the single lowest emitting kiln is 7 lb/MM tons feed (12 lb/MM tons clinker).  Applying the UPL formula discussed earlier based on the daily emissions for the best performing kiln, we calculated its 99[th] percentile UPL of performance, which results in a new source MACT level of 8.4 lb/MM tons feed (14 lb/MM tons clinker).
	Because this new source floor is on a different basis than the standard EPA promulgated in December 2006, which was a 41 ug/dscm not to be exceeded standard, it is difficult to directly compare the new source floor proposed in this action to the December 2006 standard.  The December 2006 new source mercury emissions limit was based on the performance of wet scrubber-equipped cement kilns.  In our current analysis these wet scrubber-equipped kilns were among the lowest emitting kilns, but not the lowest emitting kiln used to establish this proposed new source limit.  Based on this fact, we believe this proposed new source floor (and standard, since EPA is not proposing a beyond-the-floor standard) is approximately 30 percent lower that the December 2006 standard.  
Other Options EPA Considered in Setting Floors for Mercury
	EPA may create subcategories which distinguish among "classes, types, and sizes of sources".  Section 112 (d)(1).  EPA has carefully considered that possibility in considering potential standards for mercury emitted by portland cement kilns.  Were EPA to do so, each subcategory would have its own floor and standard, reflecting performance of the sources within that subcategory.  EPA may create a subcategory applicable to a single HAP, rather than to all HAP emitted by the source category, if the facts warrant (so that, for example, a subcategory for kilns emitting mercury, but a single category for kilns emitting HCl, is legally permissible with a proper factual basis).  Normally, any basis for subcategorizing must be related to an effect on emissions, rather than to some difference among sources which does not affect emissions performance. 
	The subcategorization possibilities for mercury which we considered are the type of kiln, presence of an inline raw mill, practice of wasting cement kiln dust, mercury concentration of limestone in the kiln's proprietary quarry, or geographic location.  Mercury emissions are not affected by kiln type (i.e., wet or dry, pre-calcining or not) because none of these distinctions have a bearing on the amount of mercury inputted to the kiln or emitted by it. In contrast, the presence of an in-line raw mill affects mercury emissions in the short term because the in-line raw mill tends to collect mercury in the exhaust gas and transfer it to the kiln feed.  However, since (as discussed above) the raw mill must be shutdown periodically for maintenance while the kiln continues to operate, all or most of the collected mercury simply gets emitted during the raw mill shutdown and total mercury emissions over time are not changed.  
	The practice of wasting cement kiln dust does affect emissions.  This practice means that a portion of the material collected on the PM control device is removed from the kiln system, rather than recycled to the kiln.  Some of the mercury condenses on the PM collected on the PM control device, so wasting CKD also removes some mercury from the kiln system (and therefore it is not emitted).  However, since this practice could be considered to "control" mercury, subcategorization by CKD wasting would be the same as subcategorizing by control device, which is not permissible. See 69 FR at 403 (Jan. 5, 2004).
      There is no variation in kiln location (i.e., geographical distinction) which would justify subcategorization.  We examined the geographical distribution of mercury emissions and total mercury and found no correlation.  For example, no one region of the country has kilns that tend to be all low or high emitting kilns.  
      We also rejected subcategorization by total mercury inputs.  Subcategorization by this method would inevitability result in a situation where kilns with higher total mercury inputs would have higher emission limits.  This is because total mercury inputs are directly correlated with mercury emissions.  So a facility that currently has lower mercury inputs could potentially simply substitute a higher mercury raw material without any requirement to control the additional mercury.  In addition, fuels and other additives are non-captive situations, and thus do not readily differentiate kilns by "size, class, or type".  Finally, because of the direct correlation of mercury emissions and mercury inputs, subcategorization by total mercury inputs could potentially be viewed as a similar situation to subcategorization by control device. 
 	The subcategorization option that we believe is most pertinent would be to subcategorize by the facility's proprietary limestone quarry.  All cement plans have a limestone quarry located adjacent to or very close to the cement plant.  This quarry supplies limestone only to its associated plant, and is not accessible to other plants.  Typically quarries are developed to provide 50 to 100 years of limestone, and the cement kiln is located based on the location of the quarry.  See 70 FR at 72333.  For this reason, we believe that a facility's propriety quarry is an inherent part of the process such that the kiln and the quarry together can be viewed as the affected source.  Also, the amount of mercury in the proprietary quarry can significantly affect mercury emission because (as noted above) limestone makes up about 80 percent of the total inputs to the kiln.  Thus, kilns with mercury above a given level might be considered a different type or class of kiln because their process necessarily requires the use of that higher-mercury input. 
	The facts, however, do not obviously indicate sharp disparities in limestone mercury content that readily differentiates among types of sources.  Figure 1 presents the average mercury contents of the proprietary quarries on the 89 kilns in EPA's present data base. Average Mercury Content of Limestone
0.00
200.00
400.00
600.00
800.00
1000.00
1200.00
0
10
20
30
40
50
60
70
80
90
100
Kiln Number
Avg ppb Hg in Limestone
Figure 1.  Average Mercury Concentration of Limestone      These data, as we presently evaluate them, do not readily support a subcategorization approach  -  putting aside for the moment the high mercury limestone kilns (at the far right of the distribution tail in Figure 1) which are discussed separately.  As shown in Figure 1, mercury levels in limestone are more of a continuum with no immediately evident breakpoints (again, putting aside the high-mercury limestone kilns).  More important, kilns with quarries with varied mercury content can and do have similar mercury emissions, and in many instances, limestone mercury is not the dominant source of mercury in the kilns' emissions notwithstanding that limestone is the principal volumetric input.  Thus for about 55 percent of the kilns (49 of 89), non-limestone mercury accounted for greater than 50 percent of the kiln's mercury emissions.  For nearly 70 percent of the kilns (62 of 89), limestone mercury accounted for at least one-third of total mercury emissions.
      
            Table 3.  Origins of Mercury in Portland Cement Manufacturing
      
                            Random number kiln code
                      Percent Hg from other raw materials
                             Percent Hg from fuels
                           Percent Hg from limestone
                                    Total %
                                       
                                        1356
                                         91
                                                                              1
                                                                              8
                                                                            100
                                        1538
                                         89
                                                                              1
                                                                             10
                                                                            100
                                        1630
                                         84
                                                                              2
                                                                             15
                                                                            100
                                        1530
                                         53
                                                                             32
                                                                             15
                                                                            100
                                        1610
                                         10
                                                                             73
                                                                             17
                                                                            100
                                        1494
                                         54
                                                                             28
                                                                             17
                                                                            100
                                        1560
                                         76
                                                                              5
                                                                             18
                                                                            100
                                        1219
                                         71
                                                                              8
                                                                             20
                                                                            100
                                        1335
                                         55
                                                                             21
                                                                             25
                                                                            100
                                        1597
                                         49
                                                                             26
                                                                             25
                                                                            100
                                        1437
                                         50
                                                                             25
                                                                             25
                                                                            100
                                        1559
                                         19
                                                                             55
                                                                             26
                                                                            100
                                        1246
                                         65
                                                                              9
                                                                             26
                                                                            100
                                        1316
                                         65
                                                                              9
                                                                             26
                                                                            100
                                        1308
                                          1
                                                                             72
                                                                             27
                                                                            100
                                        1521
                                          1
                                                                             72
                                                                             27
                                                                            100
                                        1536
                                          0
                                                                             73
                                                                             27
                                                                            100
                                        1520
                                         34
                                                                             38
                                                                             27
                                                                            100
                                        1253
                                         60
                                                                             11
                                                                             29
                                                                            100
                                        1639
                                         60
                                                                             11
                                                                             29
                                                                            100
                                        1390
                                         60
                                                                             11
                                                                             29
                                                                            100
                                        1323
                                         60
                                                                             11
                                                                             29
                                                                            100
                                        1663
                                         60
                                                                             11
                                                                             29
                                                                            100
                                        1655
                                         13
                                                                             57
                                                                             30
                                                                            100
                                        1591
                                         13
                                                                             57
                                                                             30
                                                                            100
                                        1582
                                         13
                                                                             57
                                                                             30
                                                                            100
                                        1364
                                          2
                                                                             66
                                                                             32
                                                                            100
                                        1286
                                          2
                                                                             65
                                                                             33
                                                                            100
                                        1436
                                         15
                                                                             50
                                                                             35
                                                                            100
                                        1396
                                         61
                                                                              4
                                                                             35
                                                                            100
                                        1443
                                         57
                                                                              5
                                                                             38
                                                                            100
                                        1660
                                         11
                                                                             50
                                                                             39
                                                                            100
                                        1371
                                         16
                                                                             44
                                                                             40
                                                                            100
                                        1619
                                         16
                                                                             43
                                                                             40
                                                                            100
                                        1594
                                         12
                                                                             46
                                                                             42
                                                                            100
                                        1331
                                         12
                                                                             44
                                                                             44
                                                                            100
                                        1417
                                          3
                                                                             53
                                                                             44
                                                                            100
                                        1240
                                          3
                                                                             53
                                                                             44
                                                                            100
                                        1233
                                         41
                                                                             14
                                                                             46
                                                                            100
                                        1638
                                          3
                                                                             48
                                                                             48
                                                                            100
                                        1635
                                         41
                                                                              7
                                                                             52
                                                                            100
                                        1220
                                         40
                                                                              6
                                                                             53
                                                                            100
                                        1294
                                         41
                                                                              5
                                                                             54
                                                                            100
                                        1256
                                         41
                                                                              5
                                                                             54
                                                                            100
                                        1350
                                         41
                                                                              5
                                                                             54
                                                                            100
                                        1343
                                         41
                                                                              5
                                                                             54
                                                                            100
                                        1604
                                         22
                                                                             23
                                                                             55
                                                                            100
                                        1327
                                         21
                                                                             23
                                                                             57
                                                                            100
                                        1259
                                         23
                                                                             20
                                                                             57
                                                                            100
                                        1615
                                         21
                                                                             21
                                                                             58
                                                                            100
                                        1375
                                         21
                                                                             20
                                                                             59
                                                                            100
                                        1448
                                         17
                                                                             24
                                                                             59
                                                                            100
                                        1337
                                         17
                                                                             24
                                                                             59
                                                                            100
                                        1481
                                         35
                                                                              5
                                                                             60
                                                                            100
                                        1435
                                         25
                                                                             13
                                                                             62
                                                                            100
                                        1484
                                         25
                                                                             13
                                                                             62
                                                                            100
                                        1463
                                         13
                                                                             25
                                                                             62
                                                                            100
                                        1421
                                         27
                                                                             11
                                                                             62
                                                                            100
                                        1439
                                         11
                                                                             27
                                                                             63
                                                                            100
                                        1415
                                         29
                                                                              7
                                                                             63
                                                                            100
                                        1200
                                          5
                                                                             32
                                                                             63
                                                                            100
                                        1218
                                          5
                                                                             32
                                                                             63
                                                                            100
                                        1226
                                         11
                                                                             26
                                                                             64
                                                                            100
                                        1589
                                         30
                                                                              5
                                                                             64
                                                                            100
                                        1268
                                          4
                                                                             31
                                                                             65
                                                                            100
                                        1225
                                         11
                                                                             23
                                                                             66
                                                                            100
                                        1643
                                          1
                                                                             33
                                                                             67
                                                                            100
                                        1674
                                          1
                                                                             32
                                                                             67
                                                                            100
                                        1592
                                         11
                                                                             21
                                                                             68
                                                                            100
                                        1650
                                          3
                                                                             28
                                                                             68
                                                                            100
                                        1251
                                         16
                                                                             13
                                                                             70
                                                                            100
                                        1265
                                         16
                                                                             11
                                                                             73
                                                                            100
                                        1315
                                          7
                                                                             19
                                                                             74
                                                                            100
                                        1239
                                         17
                                                                              8
                                                                             74
                                                                            100
                                        1302
                                          7
                                                                             17
                                                                             76
                                                                            100
                                        1686
                                         19
                                                                              6
                                                                             76
                                                                            100
                                        1248
                                         17
                                                                              6
                                                                             76
                                                                            100
                                        1419
                                         16
                                                                              8
                                                                             77
                                                                            100
                                        1692
                                         13
                                                                              8
                                                                             79
                                                                            100
                                        1693
                                          7
                                                                             13
                                                                             80
                                                                            100
                                        1324
                                          1
                                                                             16
                                                                             83
                                                                            100
                                        1339
                                          8
                                                                              9
                                                                             84
                                                                            100
                                        1376
                                          5
                                                                              8
                                                                             87
                                                                            100
                                        1690
                                          5
                                                                              8
                                                                             87
                                                                            100
                                        1688
                                          5
                                                                              8
                                                                             87
                                                                            100
                                        1609
                                         13
                                                                              0
                                                                             87
                                                                            100
                                        1581
                                          9
                                                                              3
                                                                             88
                                                                            100
                                        1647
                                          5
                                                                              7
                                                                             89
                                                                            100
                                        1629
                                          8
                                                                              0
                                                                             92
                                                                            100

      
      
       These data seem to indicate that although quarry mercury content is important, other non-proprietary inputs can and do affect mercury emissions as well, often to an equal or greater extent.  Quarries with similar limestone mercury content can and do have very different mercury emissions.  These facts, plus the general continuum in the limestone mercury data, seem to mitigate against subcategorizing on this basis for the great bulk of industry sources.   
      Moreover, as stated above, subcategorization is limited by the CAA to size, class, or type of source.  Both EPA and advance commenters applied various statistical analyses to the mercury limestone quarry data set and these analyses indicated that there could be populations of quarries that were statistically different.  However, it is unclear to us that a statistical difference in a population is necessarily the same as a distinction by size, class, or type.  More compelling facts, at least in our present thinking, are the apparent continuum of limestone mercury levels, and the fact that limestone mercury levels are less of a driver of mercury emission levels than one would expect if this is to be the basis for subcategorization across a broad set of the facilities.  EPA is also concerned that subcategorization by quarry mercury content may allow some higher-emitting facilities to do relatively less for compliance were they to be part of a separate subcategory where mercury levels of best performers were comparatively high.  (Of course, these levels could be reduced by adopting standards reflecting beyond-the-floor determinations.) Conversely, the case could occur where a lower emitter might be subject to a greater degree of control than a high emitter.  For example, if we were to establish a subcategory at 20 ppb mercury in the limestone, at kilns at just below the 20 ppb level might be required to apply mercury controls while kilns just above the 20 ppb level, which would likely include kilns that would determine the floor level of control, would have to do nothing to meet the mercury standard.  	
      Much of this analysis, however, does not apply to the kilns at the far end of the distribution, especially the two facilities shown in Figure 1 which have the highest quarry mercury contents which quarries appear to be outliers from the general population.  These sources' mercury emissions are related almost entirely to the limestone mercury content, not to other inputs.  In addition, we noted
       that if we set up a separate subcategory for these facilities, even if we proposed a beyond-the-floor standard based on the best estimated performance of control for these two facilities, their emissions limit would potentially be 500 to 800 lb/MM tons clinker, which is well above any other kiln, even when uncontrolled, in our data base, and 8 to 13 times the floor established for other existing sources (assuming no further subcategorization). 
      EPA is not proposing to create a separate subcategory for these high mercury sources.  Mercury is a dangerous neurotoxin singled out for special control under the Act's air toxics provision (see section 112(c)(6)), and kilns in a high-mercury subcategory, no matter how well controlled, would still be allowed to emit large amounts (at least pending a section 112(f) residual risk determination)).
        EPA is also mindful of the holding of Brick MACT and other decisions that EPA must account for raw material HAP contributions in establishing MACT floors, and the fact that raw materials may be proprietary or otherwise not obtainable category-wide does not relieve EPA of that obligation.  See, e.g. 479 F. 3d at 882-83.  
      There are also competing considerations here, both legal and equitable.  There is legal support for sources limited to a particular type of high-HAP feedstock being a legitimate candidate for subcategorization.  Thus, the concurring opinion in Brick MACT would expressly countenance subcategorization in situations involving sources' dependence on high-HAP raw materials to avoid situations where a level of performance achieved by some sources proves unachievable by other sources even after application of best technological controls, viewing such sources as of a different type than others in the source category.  479 F. 3d at 884-85.  A further equitable consideration is that one of the high mercury kilns here has voluntarily entered into an enforceable agreement to install activated carbon (the best control technology currently available so far as is known) to control its mercury emissions and this agreement appears to have the support of directly affected stakeholders (local citizen groups, regional and state officials).  The company is poised to begin installation of the control technology.  However, neither EPA nor the company believes that this source could physically achieve the level of the mercury floor derived from a single source category approach.  Closure of this kiln due to a technically infeasible standard for mercury, and possibly several of the other highest mercury kilns, thus is a possible consequence. 
      EPA repeats that it is not proposing any subcategories for mercury due to the nature of the HAP at issue, and EPA's desire to adopt a clearly legally defensible standard.  Nonetheless, this remains an issue EPA intends to evaluate carefully based on public comment, and expressly solicits comment addressing all aspects of determinations whether or not to subcategorize.  These comments should address not only the issue of a high-mercury subcategory (addressing plants in the upward right-hand tail of the distributional curve in Figure 1), but other sources as well.  EPA also solicits comment regarding non-limestone inputs to cement kilns, and whether there is any potential basis for considering a subcategorization approach (which passes legal muster) involving such materials.
Other Alternatives Considered for Mercury Standard
      EPA is proposing to rank sources by emission level in determining which are best performing.  We also considered another option of ranking best performers based on their relative mercury removal efficiency, and presenting a standard so-derived as an alternative to the standard based on ranking by lowest emissions.  There is some statutory support for adopting percent reduction/removal efficiency methodologies.  The MACT floor for new sources is to be based on the performance of the "best controlled" similar source, the term "control" can be read to mean control efficiency.   It can also be argued that the critical terms of section 112 (d)(3) -- "best controlled" (new) /"best performing" (existing) -- do not specify whether "best" is to be measured on grounds of control efficiency or emission level. See Sierra Club v. EPA, 167 F.3d 658, 661 (" average emissions limitation achieved by the best performing 12 percent of units' * * * on its own says nothing about how the performance of the best units is to be calculated"). Existing floors determined and expressed in terms of control efficiency are also arguably consistent with the requirement that the floor for existing sources reflect "average emission limitation achieved", since "emission limitation" includes standards which limit the "rate" of emissions on a continuous basis -- something which percent reduction standards would do.  CAA section 302(k).  There are also instances, where Congress expressed performance solely in terms of numerical limits, rather than performance efficiency, suggesting that Congress was aware of the distinction and capable of delineating it. See CAA section 129(a)(4).  
      There are also arguments that percent reduction standards are not legally permissible.  The Brick MACT opinion states in dicta that best performers are those emitting the least HAP(see 479 F. 3d at 880 referring to ("section [112 (d)(3)] requires floors based on emission levels actually achieved by best performers (those with the lowest emission levels)").  More important, the opinion stresses that raw material inputs must be accounted for in determining MACT floors. Id. at 882-83.  A problem with percent reduction standards is that they downplay the role of HAP inputs on emissions by allowing more HAP to be emitted provided a given level of removal efficiency reflecting the average of best removal efficiencies is achieved.  That would certainly be the case for portland cement kilns.  For these reasons, EPA is not proposing alternative standards for mercury expressed as percent reduction reflecting the average of the best removal efficiencies.  EPA solicits comment on this alternative from both a legal and policy standpoint, however.
2.	Beyond the Floor Determination
	We are not proposing any beyond-the-floor standards for mercury.  When we establish a beyond the floor standard we typically identify control techniques that have the ability to achieve an emissions limit more stringent than the MACT floor.  Under the proposed amendments, most existing kilns would have to have installed both a wet scrubber and activated carbon injection (ACI) for control of mercury, HCl and THC. To achieve further reductions in mercury beyond what can be achieved using wet scrubber and ACI in combination, the available options would include closing the kiln and relocating to a limestone quarry having lower mercury concentrations in the limestone, transporting low-mercury limestone in from long distances, switching other raw materials to lower the amount of limestone in the feed, wasting CKD, and installing additional add-on control devices.  For reasons discussed further below we believe that all but the latter option (add-on controls) cannot be evaluated as the basis of a national potential beyond the floor standard because the data to perform this type of analysis for each facility do not exist.  For that reason, we estimated the cost and incremental reduction in mercury emissions associated with installing another control device in series to the other controls.  The add-on controls considered included a wet scrubber and ACI.  Because ACI is less costly and is expected to have a higher removal efficiency as well as being potentially capable of potentially removing elemental mercury (using halogenated carbon) which a scrubber cannot remove, we selected ACI as the beyond-the-floor control option. 
	We estimated the costs and emission reductions for a 1.2 million tpy kiln as it would be representative of the impacts of other kilns. Annualized costs for an additional ACI system would be $1.254 million per year. The quantity of mercury leaving the upstream controls would be an estimated 3.3 lb/yr.  Assuming a 90 percent control efficiency, the additional ACI system would remove about 3.0 lb/yr of mercury for a cost-effectiveness of approximately $420,000 per lb of mercury reduction.  A 90 percent removal efficiency may be optimistic given the lower level of mercury entering the device and a removal efficiency on the order of 70 percent is more likely.  At this efficiency, the additional mercury controlled would be 2.3 lb/yr for a cost effectiveness of approximately $540,000 per pound of mercury removed. At either control efficiency, we believe cost of between $420,000 and $540,000 per pound of mercury removed is not justified and we are therefore not selecting this beyond-the-floor option.  
	There are two potential feasible process changes that have the potential to affect mercury emissions.  These are removing CKD from the kiln system and substituting raw materials, including fly ash, or fossil fuels with lower-mercury inputs. Although substituting low-mercury materials and fuel may be feasible for some facilities, this alternative would depend on site-specific circumstances and, therefore, must be evaluated on a site-by-site basis and EPA's current view is that it would not be a uniformly applicable (or quantifiable) control measure on which a national standard could be based (although as noted earlier, EPA is expressly soliciting quantified comment regarding potential substitutability of non-limestone kiln inputs).  
	Based on material balance data (feed and fuel usage, control device catch recycling and wasting, and mercury concentrations) that we gathered with our survey of 89 kilns, 58 percent of kilns waste some amount of CKD while 42 percent waste none.  Among kilns that waste CKD, the percentage reduction in mercury emissions by wasting CKD ranged from 0.13 percent to 82 percent, with an average of 16.5 percent and median of 7 percent. For kilns that waste some CKD, CKD as a percentage of total feed ranges from 0.16 percent to 13.7 percent, with a mean of 4.5 percent. Any additional emission reductions that can be achieved by wasting CKD depend on several site-specific factors including:  
   # The concentration of mercury in raw feed and fuel materials. 
   # The concentration of mercury in the CKD. 
   # The amount of CKD already being wasted.
   # The dynamics of mercury recirculation and accumulation - Internal loops for mercury exist between the control device and kiln feed storage and the kiln for long dry and wet kilns.  For preheater and precalciner kilns, there is usually an additional internal loop involving the in-line raw mill. These internal loops and the distribution of mercury throughout the process are not predictable and can only be determined empirically.
   # Mercury speciation may affect the extent to which mercury accumulates in the CKD, with particulate and oxidized mercury more likely to accumulate while elemental mercury is likely emitted and not affected by CKD wasting.
	Reducing mercury emissions through the wasting of CKD may be feasible for some kilns that do not already waste CKD or by wasting additional CKD for some kilns that already practice CKD wasting.  However the degree to which CKD can be used to reduce mercury emissions cannot be accurately estimated due to several factors.  For example, increasing the amount of CKD wasted would result in a reduction in the mercury concentration of the CKD, so that, over time, the effectiveness of wasting CKD decreases.  We do not have long-term data to quantify the relationship between amount of CKD wasted, CKD mercury concentration and emissions.  
      The ability to reduce mercury emissions by wasting more CKD also is affected by the mercury species present.  The particulate and oxidized species of mercury can accumulate in CKD, but not the elemental form.  Therefore wasting CKD will not necessarily control elemental mercury.  We do not have data that would allow us to quantify the effect of mercury speciation.  By wasting CKD, additional raw materials would be required to replace the CKD as well as additional fuel to calcine the additional raw materials, thereby offsetting to some extent the benefits of wasting CKD.  There is the further potential consideration of additional waste generation, an adverse cross-media impact EPA is required to consider is making beyond-the-floor determinations.  The interaction of these factors is complex and has not been adequately studied.  
      One cement plant has investigated the potential to reduce mercury emissions by wasting CKD.  This facility, using mercury CEMS and material balance information, estimated that wasting 100 percent of CKD when the raw mill is off (about 19,000 tons of CKD or 16 percent of total baghouse catch, or 1 percent of total feed) would reduce mercury emissions by about 4 percent.  They did not estimate the reductions in mercury emissions by wasting more CKD.  As with the potential to reduce mercury emissions using raw materials substitution, the effectiveness of CKD wasting in reducing emissions may provide cement plants the ability to reduce mercury emissions but it will have to be determined on a site-by-site basis.
	Because the degree to which mercury emissions can be reduced by material substitutions or through the wasting of CKD are site specific, these process-related work practices were not considered as beyond-the-floor options. 
	As a result of these analyses, we determined that, considering the technical feasibility and costs, there is no reasonable beyond the floor control option, and are proposing a mercury emission limit based on the MACT floor level of control.
C.	Determination of MACT for THC Emissions from Major and Area Sources
      The limits for existing and new sources we are proposing here apply to both area and major new sources.  We have applied these limits to area sources consistent with section 112(c)(6). See 63 FR 14193 (THC as a surrogate for the 112(c)(6) HAP polycyclic organic matter and polychlorinated biphenyls, plus determination to control all THC emissions from the source category under MACT standards).
1.  Floor Determination
Selection of existing source floor

      For reasons previously discussed in the initial proposal of the Portland Cement NESHAP (63 FR 14197, March 24, 1998), we are proposing to use THC as a surrogate for non-dioxin organic HAP that are emitted from the kiln (as is the current rule).  The THC data used to develop the MACT floor were obtained from 12 kilns using CEMS to continuously measure the concentration of THC exiting each kiln's stack.  Only kilns 1 (regenerative thermal oxidizer (RTO)) and kilns 11 and 12 (ACI) have THC emissions controls which remove or destroy THC.  We also obtained THC data from manual stack tests, typically based on 3 one hour runs per test.  The CEMS data are superior to the results of a single stack test for characterizing the long term performance and in determining the best performing kilns with respect to THC emissions for several reasons.  The manual stack test is of short duration and only represents a snapshot in time; consequently, it provides no information on the variability in emissions over time due to changes in raw material feed or in kiln operating conditions.  In contrast, the CEMS data include measurements that range from 31 consecutive days to almost 900 days of operation for the various kilns.  This extended duration of the CEMS test data gives us confidence that for any particular kiln CEMS data will capture the variability associated with the long-term THC emissions data, and thus give the most accurate representation of a source's performance.  In addition, a MACT standard based on CEMS data would be consistent with the way we are proposing to implement the THC emission limit (i.e., by requiring continuous monitoring with a THC CEMS).
      In order to set MACT floors we are ranking the kilns based on the average THC emissions levels (in ppmv) achieved (i.e., each kiln's averaged performance, averaged over the number of available measurements.  This ranking is shown in Table 4.  
                  Table 4.  Summary of THC CEMS Data and MACT Floor
                                     Kiln
                                    Average
                              Number of readings
                                   Kiln type
                               In-line raw mill
Kiln 1
                                      4.0
                                      35
Preheater/precalciner
                                      yes
Kiln 2
                                      5.6
                                      695
Wet
                                      no
Kiln 3
                                      6.8
                                      692
Long dry
                                      no
Kiln 4
                                      6.8
                                      31
Preheater/precalciner
                                      yes
Kiln 5
                                     11.1
                                      702
Long dry
                                      no
Kiln 6
                                     23.7
                                      470
Preheater/precalciner
                                      no
Kiln 7
                                     45.0
                                      742
Preheater/precalciner
                                      yes
Kiln 8
                                     51.6
                                      774
Preheater/precalciner
                                      yes
Kiln 9
                                     51.9
                                      843
Preheater/precalciner
                                      yes
Kiln 10
                                     62.8
                                      880
Preheater/precalciner
                                      yes
Kiln 11 and Kiln 12 Combined
                                     748.1
                                      790
Wet
                                      no
Existing Source Average (ppmvd at 7% O2, propane)
                                      4.8
Variability (t*vT[0.5])
                                      1.9
Existing Source 99[th] percentile (ppmvd at 7% O2, propane)
                                       7
New Source Average (ppmvd at 7% O2, propane)
                                      4.0
Variability (t*vT[0.5])
                                      1.5
New Source 99[th] percentile (ppmvd at 7% O2, propane)
                                       6
      
      
      The average performance of the best performing 12 percent of kilns (2 kilns) is 4.8 ppmvd THC (a daily average expressed as propane at 7 percent oxygen).  We calculated variability based on the variances of the two lowest emitting kilns.  This includes day-to-day variability at the same kiln, variability among the two lowest emitting kilns, and because one dataset included 695 daily measurements, it represents long term variability at a single kiln. We calculated the MACT floor (7 ppmvd) based on the UPL (upper 99[th] percentile) as described earlier from the average performance of the 2 lowest emitting kilns, Students t-factor, and the total variability, which was adjusted to account for the lower variability when using 30 day averages. 
Selection of new source MACT floor

      The new source MACT floor would be the best performing similar source accounting for variability, which would be 6 ppmvd.  We used the same procedure in estimating variability for the new source based on the 35 observations reported.  
       In this case the proposed new and existing source MACT floors are almost identical because the best performing 12 percent of kilns (for which we have emissions information) is only two sources.  The reason we look to the best performing 12 percent of sources is that the cement kiln source category consists of 30 or more kilns.  Section 112 (d)(3) states that if the source category or subcategory contains 30 or more sources then the best performing 12 percent of the kilns for which the administrator has data must be used to set the existing source MACT floor.
  However, in cases where there are 30 or more sources but little emission data this results in only a few kilns setting the existing source floor with the result that the new and existing source MACT floors are almost identical.  In contrast, if this source category had less than 30 sources, we would be required to use the top five best performing sources, rather than the two that comprise the top 12 percent.  Section 112 (d)(3)(B).  
We are seeking comment on whether, with the facts of this rulemaking, we should consider reading the intent of Congress to allow us to consider five sources rather than just two.  First, it seems evident that Congress was concerned that floor determinations should reflect a minimum quantum of data: at least data from five sources for source categories of less than 30 sources (assuming that data from five sources exist).  Second, it does not appear that this concern would be any less for source categories with 30 or more sources.  The concern, in fact, would appear to be greater.  That is, floors for categories with 30 or greater sources should not be based on a smaller number of best performing sources than source categories of fewer than 30 sources.  We note further that if we were to use five sources as best THC performers here, the existing source floor would be 10 ppmvd.  We are specifically requesting comment on interpretive and factual issues relating to the proposed THC floors, and also reiterate requests for further THC performance data, especially from kilns equipped with CEMs.  


      


EPA is also proposing an alternative floor for non-dioxin organic HAP, based on measuring the organic HAP itself rather than the THC surrogate.  This equivalent alternative limit  would provide additional flexibility in determining compliance, and it would be appropriate for those rare cases in which methane and ethane comprise a disproportionately high amount of the organic compounds in the feed because these non-HAP compounds could be emitted and would be measured as THC.  A previous study that compared total organic HAP to THC found that the organic HAP was 23 percent of the THC.  We also analyzed additional data submitted during the development of this proposed rule that included simultaneous measure of organic HAP species and THC.  Data were available from five tests, and the organic HAP averaged 24 percent of the THC.  Based on these analyses, we are proposing an equivalent alternative emission limit for organic HAP species of 2 ppmv (i.e., 24 percent of 7 ppmv) for existing sources and 1 ppmvd for new sources.  The specific organic compounds that will be measured to determine compliance with the alternative to the THC limit are benzene, toluene, styrene, xylene (ortho-, meta-, and para-), acetaldehyde, formaldehyde, and naphthalene.  These were the organic HAP species that were measured along with THC in the emissions tests that were reviewed. Nearly all of these organic HAP species were identified in an earlier analysis of the organic HAP concentrations in THC in which the average concentration of organic HAP in THC was 23 percent. 
Other Options Considered
      We also examined the THC results to determine if subcategorization by type of kiln was warranted and concluded that the data were insufficient for determining that a distinguishable difference in performance exists based on the type of kiln.  The top performing kilns in Table 4 include various types:  wet, long dry, and preheater/precalciner kilns; older (wet kilns) and newer (precalciner kilns); and those with and without in-line raw mills.  Although the type of kiln and the design and operation of its combustion system may have a minor effect on THC emissions, the composition of the feed and the presence of organic compounds in the feed materials apparently have a much larger effect.  For example, organic compounds in the feed materials may volatilize and be emitted before the feed material reaches the high temperature combustion zone of the kiln where they would have otherwise been destroyed. 
      We also evaluated creating separate subcategories for kilns with in-line raw mills and those without.  With an in-line raw mill kiln, exhaust is used to dry the raw materials during the grinding of the raw meal.  This drying step can result in some organic material being volatilized, thus increasing the THC emissions in the kiln exhaust.  This means that kilns with in-line raw mills would, on average, have higher emissions than kilns without in-line raw mills.  The existence, or absence, of a raw mill is believed to have a distinct effect on emissions of THC, as one would expect.  It is difficult to generalize that difference because the effect of the raw mill will vary based on the specific organic constituents of the raw materials.  In tests at one facility, THC emissions, on average, were 35 percent higher with the raw mill on than when the raw mill was off.
      This physical difference could justify subcategorization based on the presence of an in-line raw mill.  There are also potential policy reasons for doing so.  If we were not to subcategorize, this might discourage the use of in-line raw mills because, to meet a THC standard, in-line raw mill-equipped kilns would potentially have to utilize An RTO.  Use of RTOs has various significant adverse environmental consequences, including increase in emissions of criteria pollutants, and significant extra energy utilization with attendant increases in greenhouse gas emissions. 
      EPA has performed floor calculations for subcategories of kilns with and without in-line raw mills.  The result of that calculation, where we were using the top 12 percent, was that the floor for kilns with in-line raw mills were actually lower than those without, which is atypical: sources with in-line raw mills will typically have higher emissions because of the extra volatilization.  We believe this anomalous result is the artifact of the small data set used to calculate the existing source MACT floor.  Based on these results, we have concluded that the current data are not sufficient to allow us to subcategorize by the presence of an in-line raw mill, but would consider subcategorizing if additional data become available.  We are specifically requesting comment on subcategorization by the presence or absence of an in-line raw mill and requesting data on this issue.   
2.	Beyond the Floor Determination
Practices and technologies that are available to cement kilns to control emissions of organic HAP include raw materials material substitution, ACI systems and limestone scrubber and RTO.  We do not think it is appropriate to develop a beyond-the-floor control option based on material substitution, the feasibility of which can only be determined on a site-by-site basis. We also think the proposed limits for THC will encourage kiln owners and operators to consider material substitution without the need for specific requirements to do so.  
We examined the use of either ACI systems or RTO (with a dedicated wet scrubber) as the basis for potential beyond-the-floor THC standards for existing and new sources.  (We did not examine other beyond-the-floor regulatory options for existing or new sources because there are no controls that would, on average, generate a greater THC reduction than a combination of a wet scrubber/RTO.)  These technologies are currently in limited use in the source category.  At one facility, activated carbon is injected into the flue gas and collected in the PM control device.  The activated carbon achieved a THC emissions reduction of approximately 50 percent, and the collected carbon is then injected into the kiln in a location that insures destruction of the collected THC.  The THC emissions from this facility are the highest for any facility for which we have data due to very unusual levels of organic material in the limestone and may not be representative of the performance that can be achieved by kilns with more typical THC emissions. 
ACI has been demonstrated in other source categories, such as various types of waste incinerators including municipal waste incinerators, to reduce dioxin/furan by over 95 percent (Chi and Chang, Environmental Science and Technology, vol 39, issue 20, October 2005; Roeck and Sigg, Environmental Protection, January 1996).  The actual performance of ACI systems on cement kiln THC emissions are expected to be less than that achieved on dioxin/furan emissions as kiln flue gases are a mixture of volatile and semi volatile organic compounds, which vary according to the organic constituents of raw materials.  We have therefore conservatively estimated that ACI systems can reduce THC emissions by 75 to 80 percent.  A second facility has a continuously operated limestone scrubber followed by an RTO.  This facility has been emission tested and showed volatile organic compound (VOC), which are 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 carbon monoxide and THC.  Based on this information, we believe this facility represents the best possible control performance to reduce THC emissions.  
In assessing the potential beyond-the-floor options for THC, we first determined that most existing kilns would have to install an ACI system for control of THC and/or mercury.  A few kilns would be expected to install an RTO in order to get the THC proposed reductions. To evaluate the feasibility of beyond-the-floor controls, we assumed that a kiln already expected to install an ACI system would install in series an RTO including a wet scrubber upstream of the RTO to protect the RTO.  We estimated the costs and emission reductions for a 1.2 million tpy kiln as the cost effectiveness of the beyond-the-floor option would be similar for all kilns. Annualized costs for an additional RTO system would be $1.44 million per year. The quantity of THC leaving the upstream controls would be an estimated 18 tpy. At higher THC concentrations, for example 15 ppmv and above, an RTO will have a removal efficiency of about 98 percent. This mass of THC leaving the device upstream of and entering the RTO is equivalent to a THC concentration of about 3 ppmv.  At this low level, an RTO's removal efficiency is expected to be no better than 50 percent. At a 50 percent control efficiency, the RTO would reduce THC emission by about 9 tpy for a cost-effectiveness of approximately $157,000 per ton of THC removal. If the organic HAP fraction of the THC is 24 percent, 2 tpy of organic HAP would be removed at a cost effectiveness of approximately $656,000 per ton of organic HAP removed. At a cost effectiveness of $157,000 per ton of THC and $656,000 per ton of organic HAP, we believe the cost of the additional emission reduction is not justified (this is a far higher level than EPA has deemed justified in other MACT standards, for example). In addition to the high cost of control, the additional energy requirements, 7.3 million kwh/yr and 87,800 MMBtu/yr, would be significant.  Increased greenhouse gas emissions attributable to this energy use would be on the order of 12,000 tpy per source.  The additional energy demands would also result in increased emissions of NOx (21 tpy), CO, (8.5 tpy), SO2 (28 tpy), and PM10 (1 tpy) per source.  Because of the high costs and minimal reductions in THC and organic HAP as well as the secondary impacts and additional energy requirements, we are not selecting this beyond-the-floor option.
Therefore we are proposing for cement kilns an existing source THC emissions limit of 7 ppmvd and a new source limit of 6 ppmvd, measured as propane and corrected to 7 percent oxygen.  We are also proposing for an alternative organic HAP emissions limit of 2 ppmvd for existing kilns and 1 ppmvd for new kilns. 
THC Standard for Raw Material Dryers 
Some plants may dry their raw materials in separate dryers prior to or during grinding.  See 63 FR at 14204. This drying process can potentially lead to organic HAP and THC emissions in a manner analogous to the release of organic HAP and THC emissions from kilns when hot kiln gas contacts incoming feed materials. The methods available for reducing THC emissions (and organic HAP) is the same technology described for reducing THC emissions from kilns and in-line kiln/raw mills.  Based on the similarity of the emissions source and controls, we are also proposing to set the THC emission limit of materials dryers at 7 ppmvd (existing sources) and 6 ppmvd (new sources).   
The current NESHAP has an emissions limit of 50 ppmvd for new greenfield sources.  The limit is less stringent than the proposed changes in the THC emissions limits for new (as well as existing) sources.  For that reason, we are proposing to remove the 50 ppmvd emissions limit for this rule.  
D.	Determination of MACT for HCl Emissions from Major Sources

      In developing the MACT floor for HCl, we collected over 40 HCl emissions measurements from stack tests based on EPA Methods 321 and 26.  Studies have suggested that Method 26 is biased significantly low due to a scrubbing effect in the front half of the sampling train (see 63 FR at 14182).  Because of this bias, we used the HCl data measured at 27 kilns using Method 321 in determining the proposed floors for existing and new sources.  The data in ppmv corrected to 7 percent oxygen (O2) were ranked by emissions level and the top 12 percent (4 kilns) lowest emitting kilns identified.  The top 4 kilns were limited to major sources, and to sources where we had a minimum of three test runs to allow us to account for variability in setting the floor.  (Note that neither of these decisions significantly changed the final result of the floor calculation).  These emissions data are shown in Table 5.  The average of the four lowest emitting kilns is 0.31 ppmvd.  The variability for the 4 lowest emitting kilns includes the run-to-run variability of three runs for each stack test and the variability across the 4 lowest emitting kilns.
We calculated the MACT floor (2 ppmvd) based on the upper 99[th] percentile UPL from the average performance of the 4 lowest emitting kilns and their variances as described earlier. 
                           Table 5.  HCl MACT Floor
                                     Kiln
                         HCl Emissions (ppmvd @ 7% O2)
                                       1
                                     0.02
                                       2
                                     0.02
                                       3
                                     0.22
                                       4
                                     0.97
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                               MACT  -  Existing
Average
                                     0.31
Variability (t*vT[0.5])
                                     1.94
99[th] percentile
                                       2
                                 MACT  -  New
Average
                                     0.02
Variability (t*vT[0.5])
                                     0.12
99[th] percentile
                                      0.1



	MACT for new kilns is based on the performance of the lowest emitting kiln.  The average HCl emissions for the lowest emitting kiln in this data set is 0.02 ppmv.  Using the same statistical technique to apply run-to-run variability for that kiln's emissions data, the HCl MACT floor for new kilns is 0.14 ppmvd at 7 percent O2.
	For facilities that do not use wet scrubbers to meet the HCl limit, these standards would be based on a 30-day rolling average, consistent with the proposed use of CEMS (i.e., continuous measurements) for compliance.  See section E below.
	It should be noted that these emission limits are below the published detection level of the test method (EPA test method 321).  This issue is further discussed in section IV.I.
Beyond the Floor Standard for HCl
Based on the HCl emissions data, most kilns (both existing and new) would have to install limestone scrubbers in order to comply with the proposed floors for HCl.  Scrubbers are expected to reduce HCl emissions by an average of at least 99 percent.  Scrubbers added to reduce HCl emissions will also reduce emissions of SO2 and will remove oxidized mercury as well. 
      In examining a beyond-the-floor option for HCl, we evaluated the use of a more efficient HCl scrubber.  We assumed a spray chamber scrubber is sufficient to meet the MACT floor, and that scrubber is expected to remove HCl at an efficiency of 99 percent (as just noted).  However, we estimate that a packed-bed scrubber would have removal efficiency greater than a spray chamber due to its increased surface area and opportunity for contact between the scrubbing liquid and the acid gases.  We estimated the costs and emission reductions for a 1.2 million tpy kiln as the cost-effectiveness results would be similar for all kilns. Annual costs for a packed bed scrubber for a 1.2 million tpy kiln would be approximately $2.2 million. 
Assuming a control efficiency of 99.9 percent, the incremental emission reduction using the beyond-the-floor packed-bed scrubber, that is, the reduction in HCl emissions after initial control by the MACT floor control (a spray chamber scrubber), would be about 2.4 tpy. At an annual cost of $2.2 million, the cost effectiveness is $929,000 per ton of HCl removed.  Adverse non-air quality impacts, such as energy costs, water impacts, and solid waste impacts would be expected to be similar for both the floor and beyond-the-floor level of control.  Considering the high costs, high cost effectiveness and small additional emissions reduction (and adverse cross-media impacts), we do not believe that a beyond-the-floor standard for HCl is justified.  
Other Alternatives for HCl standards
One option to HCl standards that we considered would be to set a standard that used SO2 as a surrogate for HCl.  The reason to allow this option would be that some kilns already have SO2 controls and monitors.  Acid gas controls that remove SO2 also remove HCl at equal or greater efficiency.  However, we are not proposing this option because we have no data to demonstrate a direct link between HCl emissions and SO2 emissions  -  that is , it is unclear that ranking best HCl performers based on SO2 emissions would in fact identify lowest emitters or best controlled HCl sources.  We are requesting comment on the efficacy of using SO2 as a surrogate for HCl, and data demonstrating that SO2 is or is not a good surrogate for HCl.
We also considered the possibility of proposing a health- based standard for HCl.  Section 112(d)(4) allows the Administrator to set a health based standard for a limited set of HAP: "pollutants for which a health threshold has been established".  EPA may consider that threshold, with an ample margin of safety, in establishing standards under section 112 (d).  In the 2006 rule, EPA relied on this authority in declining to establish a standard for HCl, finding that no source in the category would emit HCl at levels which would exceed the No Observed Effect Level for HCl with an ample safety margin.  71 FR at 76527-29.  
However, we are not proposing a health-based standard.  This decision is based on the fact that, in addition to the 
direct effect of reducing HCl emissions, setting a MACT standard 
for HCl is anticipated to result in a significant amount of 
control for other pollutants emitted by cement kilns, most 
      notably SO2 and other acid gases, along with condensable PM, ammonia, and semi-volatile compounds.  For example, the additional reductions of SO2 alone attributable to the proposed MACT standard for HCl are 105,000 tpy.  These are substantial reductions considering the low number of facilities.  Although MACT standards may only address HAP, not criteria pollutants, Congress fully expected MACT standards to have the collateral benefit of controlling criteria pollutants as well, and viewed this as an important benefit of the air toxics program.  S. Rep. No. 101-228 101[st] Cong. 1[st] sess. at 172.  It therefore is appropriate that EPA consider such benefits in determining whether to exercise its discretionary section 112 (d)(4) authority. 
It should also be noted that the CAA gives EPA the option to create a health-based standard for threshold pollutants.  Generally, without adequate evidence that a pollutant may be a carcinogen (and therefore likely being a non-threshold pollutant), EPA has assumed there is an effect threshold.  For HCl, the Integrated Risk Information System (IRIS) indicates that EPA has derived an inhalation reference concentration for HCl of 20 ug/m[3].  Long-term exposure at or below this level is believed to be without appreciable risk of chronic non-cancer effects.  However, HCl has not been evaluated by the IRIS program to determine its carcinogenicity.  Additionally, the International Agency for Research and Cancer (IARC) found HCl not classifiable as a carcinogen to humans due to inadequate evidence in humans and lab animals. We request comment on the evidence necessary to determine whether a HAP, in this case HCl, is or is not a threshold pollutant, and any additional data on the carcinogenicity of HCl, and other information on HCl health and environmental effects we should consider.  Commenters should also address the issue of other environmental benefits which might result from control of HCl at a MACT level, including control of other acid gases and control of secondary PM (i.e., PM condensing from acid gases).  We will consider these comments in making an ultimate determination as to whether to adopt a health-based standard for HCl.
Finally, we determined that even if we opted to set a health based standard, we would still need to set a numerical emission limit given that section 112(d)(4) still requires that an actual emission standard be in place.  In order to determine this level, we conducted a risk analysis of 68 facilities using a screening level dispersion model (AERSCREEN).  Utilizing site specific stack parameters and worst-case meteorological conditions, AERSCREEN predicted the highest ground level concentration surrounding each facility. The results of this analysis indicated that an emission limit of 23 ppmv or less would result in no exceedances of the NOEL for HCl with a margin of safety.  Although, as discussed above, EPA is not proposing a health-based standard, EPA solicits comment on the level of 23 ppmv (as a not-to-exceed standard) should EPA decide to pursue the option of a health-based standard. 
E.	Determination of MACT for PM Emissions from Major and Area Sources
 
	Existing and new major sources are presently subject to a PM limit of 0.3 lb/ton of feed which is equivalent to 0.5 lb/ton clinker.  EPA is proposing to amend this standard, and also is proposing PM standards for existing and new area source cement kilns.  In all instances, PM serves as a surrogate for nonvolatile metal HAP (a determination upheld in National Lime Ass'n, 233 F. 3d at 637-39).  EPA is proposing to revise these limits because they do not appear to represent MACT, but rather a level which is achievable by the bulk of the industry. See 63 FR at 14198.  This is not legally permissible.  Brick MACT, 479 F. 3d at 880-81. 
      We compiled PM stack test data for 45 kilns from the period 1998 to 2007.  EPA ranked the data by emissions level and the lowest emitting 12 percent, 6 kilns, was used to develop the proposed existing source MACT floor.  
	As for the previous floors, we calculated the variances of each kiln and accounted for variability by determining the 99[th] percentile UPL as described earlier.  The average performance for each of the lowest emitting kilns was generally based on the average of 3 runs which comprise a stack test.  Consequently, the variability represents the short term variability at a kiln (e.g., a 3 hour stack test period) and the variability across the 6 lowest emitting kilns.  (This analysis is consistent with the way we would propose to determine compliance, i.e., conduct 3 runs to perform a stack test.)  For the lowest emitting kiln (whose performance was used to establish the new source floor), there were only 3 runs with results that were relatively close together, which is inadequate to estimate the kiln's long term variability.  However, we know the 6 lowest emitting kilns are equipped with fabric filters that are similar with respect to performance because they are similar in design and operation, and the larger dataset provides a much better estimate of the variability associated with a properly operated fabric filter.  Consequently, for the proposed new source floor, we used the average performance of the lowest emitting kiln and the variability associated with the best fabric filters to assess the best performing kiln's variability.
      The emissions for the top six kilns ranged from 0.005 to 0.008 lb/ton clinker.  Accounting for variability as described above, we calculated an existing source MACT floor of 0.085 lb/ton clinker.  For new kilns, the limit is based on the best lowest emitting kiln, which has emissions of 0.005 lb/ton clinker.  Accounting for variability results in a calculated new source MACT floor of 0.080 lb/ton clinker.  The PM emissions data are summarized in Table 6.

                            Table 6.  PM MACT Floor
                                     Kiln
                         PM Emissions (lb/ton clinker)
                                       1
                                     0.005
                                       2
                                    0.0075
                                       3
                                    0.0075
                                       4
                                    0.0081
                                       5
                                    0.0108
                                       6
                                    0.0232
                                MACT - Existing
Average
                                     0.010
Variability (t*vT[0.5])
                                     0.075
99[th] percentile
                                     0.085
                                  MACT - New
Average
                                     0.005
Variability (t*vT[0.5])
                                     0.075
99[th] percentile
                                     0.080


	EPA is also proposing to set a PM standard based on MACT for existing and new area source cement kilns.  Portland cement kilns are a listed area source category for urban HAP metals pursuant to section 112(c)(3), and control of these metal HAP emissions (via the standard for the PM metal surrogate) is required to ensure that area sources representing 90 percent of the area source emissions of urban metal HAP are subject to section 112 control, as required by section 112(c)(3).  EPA is proposing that this standard reflect MACT, rather than GACT, because there is no essential difference between area source and major source cement kilns with respect to emissions of either HAP metals or PM.  A common control strategy consequently is warranted for these emissions.  Thus, the factors that determine whether a cement kiln is major or area are typically a function of the source's HCl or formaldehyde emissions, rather than its emissions of HAP metals.  As a result, there are kilns that are physically quite large that are area sources, and kilns that are small that are major sources.  Both large and small kilns have similar HAP metal and PM emissions characteristics and controls.  We thus have included all cement kilns in the floor calculations for the proposed PM standard, and have developed common PM limits based on MACT for both major and area sources.  
Consideration of Beyond-the-Floor Standards
      There is very little difference in the proposed floor levels for PM for either new or existing sources, and we believe that a well-performing baghouse represents the best performance for PM.  To evaluate beyond-the-floor controls, we examined the feasibility of replacing an existing ESP or baghouse with a new baghouse equipped with membrane bags which might result in a slightly better performance for PM (reflected in the modest increment between the proposed floors for new and existing sources). We estimated the costs and emission reductions for a 1.2 million tpy kiln. The cost-effectiveness results will be similar for all kilns. Under the MACT floor, baseline emissions of 0.34 lb/ton of clinker are reduced to 0.085 lb/ton of clinker, a reduction in PM emission of 51 tpy. Further reducing emissions down to the proposed PM limit for new sources would incrementally reduce emissions by an additional 3 tpy. The annualized cost of a baghouse with membrane bags would be $1.73 million per year, or a cost effectiveness of $576,000/ton of PM (far greater than any PM reduction EPA has ever considered achievable under section 112(d)(2) or warranted under other provisions of the Act which allow consideration of cost). Assuming that the metal HAP portion of total PM is 1 percent, the cost effectiveness would be about $58 million per ton of metal HAP. Based on these costs and the small resulting emission reductions, we believe a PM beyond-the-floor standard is not justified for existing sources and not technically feasible for new sources.
Other Standards for PM
      Emissions from fabric filters or ESP are typically measured as a concentration (grains per dry standard cubic feet) and then converted to the desired format using standard conversions (54,000 dry cubic feet per minute of exhaust gas per ton of feed, 1.65 tons of feed per ton of clinker).  All of the data used to set the proposed PM emissions limit were converted in that fashion.  Therefore, the basis of the proposed PM standard is actually a concentration level.  There are certain cases where this conversion must be adjusted, however.  Some kilns and kiln/in-line raw mills combine the clinker cooler gas with the kiln exhaust and send the combined emissions to a single control device.  There are significant energy savings (and attendant greenhouse gas emission reductions) associated with this practice, since heat can be extracted from the clinker cooler exhaust.  However, there need to be different conversion factors from concentration to mass per unit clinker.  In the case where clinker cooler gas is combined with the kiln exhaust the standard would need to be adjusted to allow for the increased gas flow.  If this allowance is not made, then the effective level of the PM standard would be reduced (the result being that the proposed standard would not properly reflect best performing kilns' performance, and also discouraging use of a desirable energy efficiency measure).  Therefore, we are proposing that facilities that combine the kiln and clinker cooler gas flows prior to the PM control would be allowed to convert the equivalent concentration standards (which are 0.0067 or 0.0063 for new and existing sources, respectively) to a lb/ton clinker standard using their combined gas flows (dry standard cubit feet per ton of feed).  It should be noted that this provision will not result in any additional PM emissions to the atmosphere compared to the same kiln if it did not combine the clinker cooler and kiln exhaust, and may actually decrease emissions slightly due to improvements in overall process efficiency. 
	In addition to proposing to amend the PM standard for kilns we are also proposing to similarly amend the PM emissions limit for clinker coolers.  Fabric filters are the usual control for both cement kilns and clinker coolers.  As EPA noted in our proposed revision to Standards of Performance for Portland Cement Plants (73 FR 34078, June 16, 2008) we believe that the current clinker cooler controls can meet the same level of PM control that can be met by the cement kiln.  Therefore, we are proposing as MACT the same PM emissions limits for both clinker coolers and kilns. 
	In sum, because we believe that the costs of a beyond-the-floor standard for PM are not justified, we are proposing a PM standard for existing kilns and clinker coolers of 0.085 lb/ton of clinker, and for new kilns and clinker coolers of 0.080 lb/ton of clinker.
F.	Selection of Compliance Provisions
	For compliance with the mercury emissions standards we are proposing to require CEMS (either instrument based or sorbent trap based).  As we have previously noted, we do not believe that short term emission tests provide a good indication of long term mercury emissions.  We considered the option of measuring and analyzing the raw materials, as was done to gather the data used to develop the proposed standards.  However, that data gathering was done based on a daily analysis of all inputs to the kiln.  If we were to make that the compliance option and require daily analyses, the cost would be comparable to the cost of a mercury monitor.  If we were to allow less frequent analyses to reduce costs, then we are concerned that the accuracy may be reduced (and the standard would no longer be implemented in the same manner as it was developed).  In addition, in order to meet the proposed mercury emission limits, we anticipate that many facilities will install add-on controls, which will create another variable that would make the measurement of mercury inputs as a surrogate for a continuous stack measurement less accurate.  In order to determine an outlet emissions rate based on input measurements, the control device would have to be tested under various operating conditions to insure that the removal efficiency could be accurately calculated, and parametric control device monitoring would be required.  Given issues related to input monitoring, and the cost associated with control device monitoring, plus a desire to implement the standard in a manner matching its means of development, we believe that a continuous mercury measure at the stack is the preferred option, and are proposing that sources demonstrate compliance with mercury monitors meeting the requirements of PS-12A or PS-12B.
	
      Generally, we propose and promulgate monitoring system performance specifications and performance test methods in accordance with their development, independent of publication of source category emissions control regulations.  There are circumstances dictating that we publish such measurement procedures and requirements simultaneously with an emissions regulation because of integral technical relationships and because such a combination is convenient and cost-effective. Such combined publication also allows commenters to prepare comprehensive comments on not only the performance specifications or test methods but also on their specific applications.  In today's notice, we propose to amend 40 CFR part 60, appendix B by adding Performance Specification 12A  -  Specifications and Test Procedures For Total Vapor Phase Mercury Continuous Emission Monitoring Systems in Stationary Sources and Performance Specification 12B - Specifications and Test Procedures For Monitoring Total Vapor Phase Mercury Emissions from Stationary Sources Using a Sorbent Trap Monitoring System. 
      We published versions of these performance specifications with the electric utility mercury MACT rule.  On March 14, 2008, the DC Circuit Court issued a mandate to vacate the Clean Air Mercury Rule which included that MACT rule clouding the status of these measurement procedures.  We are republishing the performance specifications today to clarify the status of those procedures particularly in their applicability to source categories in addition to coal-fired electric utilities.  In this case, our analyses show
       that mercury emissions from portland cement kilns exhibit most, if not all, of the same physical and chemical characteristics as mercury emissions from coal-fired electric utilities.  Since Performance Specifications 12A and 12B are suitable for use in measuring emissions from portland cement kilns, we also believe that these measurement procedures with minor revision also apply to other sources.  We believe that the simultaneous proposal of these performance specifications revised to reflect broad applicability with today's Portland Cement MACT proposal is appropriate.  The combined notice of proposals is cost-effective, and affords commenters the ability to provide comprehensive comments."
	We are aware that there are currently no cement kilns in the U.S. that have continuous mercury monitors.  However, there are numerous utility boilers that have certified mercury CEMS.  We see no technical basis to say that continuous mercury monitors will not work as well on a cement kiln as they do on a utility boiler.  In addition, there are 34 cement kilns that have operating continuous mercury monitors in Germany.
	For demonstrating compliance with the proposed THC emissions limit we are proposing the use of a CEMS meeting the requirements of PS-8A.  This requirement already exists for new kilns.  There are existing kilns that already have THC CEMS, and indeed, EPA used CEMS data from these kilns as the basis for the proposed standards.  As previously noted, changes in raw materials can materially affect THC emissions without any obvious indication that emissions have changed.  For this reason, and to be consistent with the means by which EPA developed the proposed standard, we believe (subject to consideration of public comment) a CEMS is necessary to insure continuous compliance.
      	If a source chooses to comply with the alternative organic HAP emissions limit, rather then the THC limit, we are not planning to propose the use of a continuous monitor to directly measure organic HAP because organic HAP monitors are not available for this application.  We are proposing to use EPA Method 320 to determine the actual organic HAP content of the THC at a specific facility.  If Method 320 indicates compliance with the alternative organic HAP standard, then the THC emissions measures using a CEMS would become that site's THC limit (assuming that the THC emissions measured during the testing exceed the MACT floor values of 7 ppmvd for existing sources and 6 ppmvd for new sources).   
	For demonstrating compliance with the proposed PM emissions limit, we are proposing the installation and operation of a bag leak detection system, along with stack testing using method     conducted at a frequency of five years.  If an ESP is used for PM control an ESP predictive model to monitor the performance of ESP controlling PM emissions from kilns would be required, as well as a stack performance test conducted at a frequency of five years.  As an alternative a PM CEMS that meets the requirements of PS-11 may be used. We are also proposing to eliminate the current requirement of using an opacity monitor to demonstrate continuous requirement with a PM standard for kilns and clinker coolers.
      	
We previously proposed use of bag leak detection systems for PM as part of our review of the Portland Cement Standards for Performance under section 111 of the Act (73 FR 34072, June 16, 2008).  Our rationale for extending the requirement to existing kilns is that given the stringent level of the proposed PM emissions limits we do not believe that opacity is an accurate indicator of compliance with the proposed PM emissions limit.  In addition, we are removing the opacity standard and opacity continuous monitoring requirements for any source that uses a PM CEMS or bag leak detector to determine compliance with a PM standard.  (Some opacity requirements, such as those for materials handling operations, will remain in place).  

	For demonstrating compliance with the HCl emissions limit we are proposing the use of a CEMS that meets the requirements of PS-15 if the source does not use a limestone wet scrubber for HCl control.  As with mercury and THC, HCl emissions can be significantly affected by inputs to the kiln without any visible indications.  For this reason we believe that a continuous method of compliance is warranted.  If the source uses a limestone wet scrubber for HCl control, we believe that HCl emissions will be minimal even if kiln inputs change because limestone wet scrubbers are highly efficient in removing HCl.  For this reason we are proposing to require sources using a limestone wet scrubber to perform an initial compliance test using EPA Test Method 321, and to test every 5 years thereafter.  These EPA Test Method 321 testing requirements would also apply to sources using CEMS.  In addition, for sources with in-line raw mills that are not using a wet scrubber for HCl control, we are proposing to require testing with raw mill on and raw mill off.  Our review of the available data where a kiln was tested with raw mill on/raw mill off indicated that the change in raw mill operating conditions had a significant influence in HCl emissions.  We are specifically requesting comment on our assumption that a wet scrubber will consistently maintain a low level of HCl emissions, even if feed conditions change, and thus it is appropriate to use a short term performance test rather then a continuous monitor for kilns that install wet scrubbers.
	One option we considered would be to require SO2 monitoring in lieu of HCl monitoring.  The reason to allow this option would be that some kilns already have SO2 monitors, and this monitoring technology is less expensive and more mature than HCl monitors.  If a source is using a wet scrubber for HCl control, then indication that the scrubber is removing SO2 are also a positive indications that HCl is being removed.  However, we are not proposing this because we have no data to demonstrate a direct link between HCl emissions and SO2 emissions.  For example, if a source has a scrubber-equipped kiln and notes an SO2 emissions increase, is the increase due to a drop off in scrubber performance or to an increase in sulfur compounds in the raw materials?  If it is simply a change in raw materials sulfur content, then the change may have no relevance to HCl emissions.  If the SO2 emission increase is due to a reduction in scrubber efficiency, then the change in SO2 emission might mean that HCl emission have changed.  We are requesting comment on the efficacy of using SO2 as a surrogate for HCl for purposes of monitoring compliance, and data demonstrating whether SO2 is a good surrogate for HCl for this purpose.  
	One issue in using a CEMS to measure compliance with these proposed standards is whether the use of a continuous monitor results in an increase in the stringency of the standard, if that standard was developed based on short term emissions tests or other data and is a not-to-exceed standard.  Mercury data were obtained from thirty daily samples of fuel and raw materials plus statistical techniques to account for further variability in inputs, operation, and measurement.  The proposed hydrogen chloride emissions limit were derived using statistical techniques to account for variability in components such as fuel and raw material, process operation, and measurement procedures.  The proposal would require direct, continuous measurement of mercury and, for those facilities not using a wet scrubber as a control device, hydrogen chloride.  Compliance with these emissions limits for these facilities is determined by assessing the thirty day average emissions with the appropriate emissions limit.  With respect to mercury, as explained in section       above, not only do continuous monitoring and 30-day averaging accord well with the means used to gather these underlying data, but continuous monitoring and 30-day averaging are needed because cement kilns do not emit mercury in relatively equal amounts day-by-day but, due to the mill-on/mill-off phenomenon, in varying small and large amounts.  With respect to hydrogen chloride, use of a thirty day average provides a way to account for the potential short term variability inherent in values obtained from continuous data collection and analysis, so that CEM-based compliance, in combination with 30-day averaging, does not make the proposed standard more stringent than a not-to-exceed standard based on stack testing. Therefore, subject to consideration of public comment, we believe the use of continuous monitoring techniques for mercury and HCl, in combination with 30-day averaging times, is appropriate.
G.	Selection of Compliance Dates
	For existing sources we are proposing a compliance date of 3 years after the promulgation of the new emission limits for mercury, THC, PM, and HCl take effect.  This is the maximum time period allowed by law.  See section 112(i)(3)(A).  We believe a 3 year compliance period is justified because most facilities will have to install emissions control devices (and in some cases multiple devices) to comply with the proposed emissions limits.  
	In the December 2006 rule amendments we included operating requirements relating to the amount of cement kiln dust wasted versus dust recycled, and also a requirement that the source certify that any fly ash used as a raw material did not come from a boiler using sorbent to remove mercury from the boiler's exhaust.  The removal of these requirements would take effect once the affected source is required to comply with a numerical mercury limit. 
	For new sources, the compliance date will be the date of publication of the final rule or startup, whichever is later.  In determining the proposal date that determines if a source is existing or new, we are retaining the date of December 5, 2005 for HCl, THC, and mercury, i.e., any source that commenced construction after December 5, 2005, is a new source for purposes of the emission standards changed in these amendments.  For PM, we are proposing that the date that determines if a source is existing or new will be [INSERT THE DATE OF PUBLICTION OF THESE AMENDMENTS IN THE FEDERAL REGIATER].   
	In proposing this determination, we considered three possible dates, including March 24, 1998; December 5, 2005; and the proposal date of these amendments.  Section 112 (a) (4) of the Act states that a new source is a stationary source if "the construction or reconstruction of which is commenced after the Administrator first proposes regulations under this section establishing an emissions standard applicable to such source".  "First proposes" could refer to the date EPA first proposes standards for the source category as a whole, or could refer to the date the agency first proposes standards under a particular rulemaking record.  The definition is also ambiguous with regard to whether it refers to a standard for the source as a whole, or to a HAP-specific standard (so that there could be different new source standards for different HAP which are regulated at different times).  
      We believe that the section 112 (a)(4) definition can be read to apply pollutant-by-pollutant, and that the provision applies to the rulemaking record under which a standard is developed.  The evident intent of the definition plus the substantive new source provisions is that it is technically more challenging and potentially more costly to retrofit a control system to an existing source than to incorporate controls when a source is initially designed.  Consequently, new source standards should apply to sources which are being newly constructed or reconstructed in fact. See 71 FR at 76540-541.  If, for example, we were to choose March 24, 1998, as the date to delineate existing versus new sources, then numerous kilns that would be required to meet new source standards would have to retrofit controls that they could not have reasonably anticipated at the time the source was originally designed.
      We also considered selecting the proposal date of these amendments as the date that delineates new and existing sources but, for HAP other than PM, rejected that option.  The mercury and THC standards being proposed here arise out of the rulemaking proposed on December 5, 2007.   This notice is issued in response to petitions for reconsideration of the standards from that rulemaking. The proposed standard for HCl likewise arises out of the December 2007 rulemaking and its reconsideration, and EPA proposed standards for HCl in that rulemaking.  See 70 FR at 72335-37.  Thus, it is reasonable to view the December 2005 proposal as the date on which EPA first proposed standards for HCl as part of this rulemaking.  
      For PM, the choices are the 1998 date on which EPA proposed PM standards, or the date of this proposal (the first date EPA proposed revision to the PM standard, based on a new rulemaking record). Subject to consideration of public comment, we believe the appropriate date is the date of this proposal.  See 71 FR at 76540-41 (applying new source standards to sources which began operation many years in the past is inconsistent with idea that new source standards may be more stringent because they can be implemented at time of initial design of the source, thus avoiding retrofit expense). 
      We are establishing a compliance date for the THC emissions limit for new sources as December 21, 2009 or the effective date of these amendments, whichever is later.  A new source which commenced construction after December 2, 2005 and before December 20, 2006 would have three years from the date of publication of the final amendments to comply.  See section 112(i)(2).
H. Discussion of EPA's Sector Based Approach for Cement Manufacturing 
What is a Sector-Based Approach?
	Sector-based approaches are based on integrated assessments that consider multiple pollutants in a comprehensive and coordinate manner to manage emissions and CAA requirements.  One of the many ways we can address sector-based approaches is by reviewing multiple regulatory programs together whenever possible. This approach essentially expands the technical analyses on costs and benefits of particular technologies, to consider the interactions of rules that regulate sources.  The benefit of multi-pollutant and sector-based analyses and approaches include the ability to identify optimum strategies, considering feasibility, costs, and benefits across all pollutant types  -  criteria, toxics and others -- while streamlining administrative and compliance complexities and reducing conflicting and redundant requirements, resulting in added certainty and easier implementation of control strategies for the sector under consideration. 
Portland Cement Sector-Based Approach
	Multiple regulatory requirements currently apply to the cement industry sector. In order to benefit from a sector-based approach for the cement industry, EPA analyzed how the NESHAP under reconsideration relates to other regulatory requirements currently under review for portland cement facilities. The requirements analyzed affect HAP and/or criteria pollutant emissions from cement kilns and cover the NESHAP reconsideration, area source NESHAP, NESHAP technology review and residual risk, and the New Source Performance Standard (NSPS) revision. The results of our analyses are described below. 
	The first relationship is the interaction between the NESHAP THC standard and the co-benefits for VOC and carbon monoxide (CO) control. The THC limit for new sources in the NESHAP will also control VOC and CO to the limit of technical feasibility.  For this reason the proposed NSPS relies on the THC NESHAP limit for new sources to represent best demonstrated technology (BDT) for VOC and CO for this source category.  See 73 FR 34082.
	Another interaction relates to the more stringent PM emission limit being proposed under the NESHAP reconsideration.  As noted, there is a legal requirement to regulate listed urban HAP metals from area source cement kilns under section 112(c)(3), and we are proposing PM standards for area source cement kilns pursuant to that obligation.  In addition, we are required under CAA section 112(f) to evaluate the residual risk for toxic air pollutants emitted by this source category and to perform a technology review for this source category under section 112(d)(6). Revisions to the PM standard for new and existing major sources under the NESHAP will maximize environmental benefits due to the achievement of greater PM emission reductions and will also reduce the possibility for additional control requirements as we consider the implication these revisions have in developing future requirements under residual risk and technology review increasing certainty to this sector.  
	To reduce conflicting and redundant requirements for the cement industry regarding the control of PM emissions, EPA is proposing to place language in both the NESHAP and the NSPS making it clear that if a particular source has two different requirements for the same pollutant, they are to comply with the most stringent emission limit, and are not subject to the less stringent limit. 
	Another issue being addressed as part of our cement sector strategy is condensable PM.  Particulate emissions consist of both a filterable fraction and a condensable fraction. The condensable fraction exists as a gas in an exhaust stream and condenses to form particulate once the gas enters the ambient air.  In this rulemaking, AP-42 emission factors were used to calculate emission reductions of PM2.5 filterable due to the PM standard.  There are insufficient data to assess if the cement industry is a significant source of condensable PM. The measurement of condensable PM is important to EPA's goal of reducing ambient air concentrations of PM2.5.  While the Agency supports reducing condensable PM emissions, the amount of condensable PM captured by Method 5 (the PM compliance test method specified in the NSPS) is small relative to methods that specifically target condensable PM, such as Method 202 (40 CFR part 51, Appendix M). Since promulgation of Method 202 in 1991, EPA has been working to overcome problems associated with the accuracy of Method 202 and plans to promulgate improvements in the future. In order to assist in future sector strategy development, we are considering any data available on the levels of condensable PM emitted by the cement industry; any condensable PM emission test data collected using EPA Conditional Method 39, EPA Method 202 (40 CFR part 51, Appendix M), or their equivalent, factors affecting those condensable PM emissions, and potential controls. 

	Another benefit of evaluating regulatory requirements across pollutants in the context of a sector approach is addressing the relationship between the regulatory requirements for SO2, mercury, and HCl emissions.  Although SO2 emission reductions would be required in the proposed NSPS, mercury and HCl emissions reduction are required in the Portland Cement NESHAP reconsideration.  The integrated analysis of these regulatory requirements showed that alkaline wet scrubbers achieve emission reductions for SO2, mercury, and HCl from cement kilns.  This control technology maximizes the co-benefits of emission reductions while minimizing cost. For example, a new facility that under the NSPS determines a moderate level of SO2 reduction might consider using a lime injection system because it is lower cost. However, if the same facility would have to use some type of add-on control to meet the NESHAP new source mercury and/or HCl emission limits, instead of considering each standard in isolation, would determine that the cheapest overall alternative might be to use a wet scrubber for controlling SO2, mercury, and/or HCl. By coordinating requirements at the same time, the facility can determine which control technology minimizes the overall cost of air pollution control and can avoid stranded costs associated with piecemeal investments in individual control equipment for SO2, mercury, and/or HCl.
	The integrated sector-based analysis for the cement industry also showed that SO2 emission reductions from existing sources are possible as co-benefits if wet scrubbers are employed to control either mercury and/or HCl from existing sources under the NESHAP. We evaluated the co-benefits of the use of wet scrubbers in reducing SO2 and the effects on PM2.5 and PM2.5 nonattainment areas (NAA), including the co-benefits of reducing SO2 in mandatory Federal Class I areas (Class I areas).
	Another interaction addressed in the context of the sector approach is monitoring requirements.  To ensure that our sector strategy reduces administrative and compliance complexities associated with complying with multiple regulations, our rulemaking recognizes that where monitoring is required, methods and reporting requirements should be consistent in the NSPS and NESHAP where the pollutants and emission sources have similar characteristics. 
New Source Review and the Cement Sector-based Approach
	The proposed MACT requirements for cement facilities have a potential to result in emissions reductions of air pollutants that are regulated under the CAA's major new source review (NSR) program.  Specifically, operating a wet scrubber to meet MACT requirements for mercury and/or HCl at a portland cement plant has the added environmental benefit of reducing large amounts of SO2, a regulated NSR pollutant.  For a typical wet scrubber, with a 90 percent removal efficiency for SO2, this could result in an annual reduction of thousands of tons of SO2 from an uncontrolled kiln (reduction will vary greatly depending on the type and age of the kiln, sulfur content of feed materials, and fuel type).  These collateral SO2 and other criteria pollutant emissions reductions resulting from the application of MACT may be considered for "netting" and "offsets" purposes under the major NSR program.
	The term "netting" refers to the process of considering certain previous and prospective emissions changes at an existing major source over a contemporaneous period to determine if a "net emissions increase" will result from a proposed modification.  If the "net emissions increase" is significant, then major NSR applies.  Section 173(a)(1)(A) of the Act requires that a major source or major modification planned in a nonattainment area obtain emissions offsets as a condition for approval.  These offsets are generally obtained from existing sources located in the vicinity of the proposed source and must offset the emissions increase from the new source or modification and provide a net air quality benefit.  
	An emissions reduction must be "surplus," among other things, to be creditable for NSR netting and offset purposes.  Typically emission reduction required by the CAA are not considered surplus.  For example, emissions reductions already required by an NSPS, or those that are relied upon in a State implementation plan (SIP) for criteria pollutant attainment purposes (e.g., Reasonable Available Control Technology, reasonable further progress, or an attainment demonstration), are not creditable for NSR offsets (or netting) since this would be "double counting" of the reductions.  Also, any emissions reductions already counted in previous major modification "netting" may not be used as offsets. However, emissions reductions that are in excess of, or incidental to the MACT standards, are not precluded from being surplus even though they result from compliance with a CAA requirement.  Therefore, provided such reductions are not being double counted, they may qualify as surplus and can either be used either as netting credits at the source or be sold as emissions offsets to other sources in the same non-attainment area provided the reductions meet all other otherwise applicable CAA requirements for being a creditable emission reduction for use as an offset or for netting purposes. 
	Since SO2 is presumed a PM2.5 precursor in all prevention of significant deterioration and nonattainment areas unless a state specifically demonstrates that it is not a precursor, SO2 may be used as a emission reduction credit for either SO2 or PM2.5, at an offset ratio is 40-to-1 (40 tons of SO2 to 1 ton of PM2.5) See 72 FR 28321-28350 (May 16, 2008).
	Given that many states have concerns over a lack of direct PM2.5 emissions offsets for areas that are designated nonattainment for PM2.5, cement plants that generate creditable reductions of SO2 from applying MACT controls may realize a financial benefit if they can sell the emissions credits as SO2 and/or PM2.5 offsets.  While it is difficult to quantify the exact financial benefit, since offset prices are market driven and vary widely the U.S., we know that prices for PM2.5 emissions credits can reach $40,000 in some nonattainment areas, and may still be higher in others.  For the sake of approximation, using $20,000 for an average price per ton of a PM2.5  offset, a cement plant that creates a 2,000 tons per year reduction in SO2 can potentially sell the emissions credits for as much as $1,000,000 per year (i.e., 2000 tpy / 40_ratio x $20,000/ton), as long as the reductions are creditable and surplus.
National Ambient Air Quality Standards
	Portland cement kilns emit several pollutants regulated under the NAAQS, including PM2.5, SO2, NOx, and precursors to ozone.  In addition, several pollutants emitted from cement kilns are transformed in the atmosphere into PM2.5, including SO2, NOx, and VOC.  Emissions of NOx and VOC are also precursors to ozone.  Thus, implementation of the Cement NESHAP, which could lead to substantial reductions in criteria pollutants and precursor emissions as co-benefits, could help areas around the country attain the NAAQS.  
	Screening analyses showed that 23 cement facilities were located in 24hr PM2.5 NAA and 39 facilities in Ozone NAA.  Control strategies for reducing emissions of THC, mercury, HCl, and PM from cement plants under the Cement NESHAP have the co-benefits of reducing SO2 and direct PM2.5 emissions.  These co-benefits could provide states with emission reductions for areas required to have attainment plans.
Regional Haze, Reasonable Progress, and the Cement Sector-based Strategy
	The Cement NESHAP can also have an impact on regional haze.  Under section 169A of the CAA, States must develop SIPs to address regional haze.  The purpose of the regional haze program is the prevention of any future, and the remedying of any existing, impairment of visibility in mandatory Class I areas which impairment results from manmade air pollution Under the regional haze regulations, the first Regional Haze SIPs were due in December, 2007 (40 CFR 51.308(b)); these SIP submittals must address several key elements, including Best Available Retrofit Technology (BART), Reasonable Progress, and long-term strategies.  Screening analyses showed that there are 14 cement facilities within a distance of 50 km Class 1 Areas.
	A potential benefit for cement facilities utilizing wet scrubbers to comply with this rule is a level of certainty for satisfying a facility's BART requirements for SO2 under the regional haze program.  This rule may establish a framework for States to include certain control measures or other requirements in their regional haze SIPs where such a program would be "better than BART."  A facility must comply with BART as expeditiously as practicable but no later than 5 years after the regional haze SIP is approved.  A state may be able to rely on this rule to satisfy the BART requirements for a NESHAP affected source utilizing a wet scrubber if (1) the compliance date for a source subject to this NESHAP falls within the BART compliance timeframe, (2) the proposed controls are more cost effective than the controls that would constitute BART, and (3) the visibility benefits of the controls are at least as effective as BART.
	States may also allow sources to "average" emissions across any set of BART-eligible emissions units within a fence-line, provided the emissions reductions from each pollutant being controlled for BART are equal to those reductions that would be obtained by simply controlling each of the BART-eligible units that constitute the BART-eligible source (40 CFR 51.308(e)(2)). This averaging technique may also be advantageous to cement facilities subject to this NESHAP that also have BART-subject sources.
	Under the regional haze rule, States may develop an alternative "better than BART" program in lieu of source-by-source BART.  The alternative program must achieve greater reasonable progress than BART would toward the national visibility goal.  The alternative program may allow more time for compliance than source-by-source BART would have allowed.  Any reductions relied on for a better than BART analysis must be surplus as of the baseline year the State relies on for purposes of developing its regional haze SIP (i.e., 2002) and can include reductions from non-BART and BART sources.  Visibility analyses must verify that the alternative program, on average, gets greater visibility improvement than BART and that no degradation in visibility on the best days occurs (40 CFR 51.308(e)(3)).
	EPA believes that emissions units at cement sources found to be subject to BART and that will be required to install controls or otherwise achieve emissions reductions per the regional haze regulations can benefit from this Cement NESHAP to potentially satisfy the regional haze requirements.  EPA will need to demonstrate that the implementation of the cement NESHAP will result in SO2 emissions reductions and related visibility improvements that are greater than reductions achieved through the application of BART controls.  If EPA demonstrates that the SO2 emissions reductions and visibility and air quality improvements resulting from the rule are better than BART, this demonstration, when incorporated into the Regional Haze SIP, is anticipated to fulfill federal regulatory requirements associated with BART requirements for cement facilities. 
	Additionally, the level of control achieved through the Cement NESHAP may contribute toward, and possibly achieve, the visibility improvements needed to satisfy the reasonable progress requirements of the regional haze rule for cement facilities through the first Regional Haze planning period.  States can submit the relevant regional haze SIP amendments once this rule becomes final.  
Health Benefits of Reducing Emissions from Portland Cement Kilns
	Implementation of the Cement NESHAP, which could lead to substantial reductions in PM2.5, SO2, and toxic air pollutants, could reduce numerous health effects.  
	Section VI.J of this preamble provides a summary of the monetized human health benefits of this proposed regulation based on the Regulatory Impact Analysis available in this docket that includes more detail regarding the costs and benefits of this proposed regulation.  
	As mentioned before, portland cement kilns emit several pollutants with known human health effects, including PM2.5, SO2, NOx, and precursors to ozone. Exposure to PM2.5 is associated with significant respiratory and cardiac health effects, such as premature mortality, chronic bronchitis, nonfatal heart attacks, hospital admissions, emergency department visits, asthma attacks, and work loss days. USEPA, Air Quality Criteria for Particulate matter, chapter 9.2 (October 2004).  Exposure to SO2 and NOx is associated with increased respiratory effects, including asthma attacks, hospital admissions, and emergency department visits.  Exposure to ozone is associated with significant respiratory health effects, such as premature mortality, hospital admissions, emergency department visits, acute respiratory symptoms, school loss days.  
	In addition, portland cement kilns emit toxic air pollutants, including mercury and HCl.  Exposure to high levels of mercury is associated with central nervous system damage, kidney damage, blindness, deafness, speech difficulties, and developmental effects.  Acute inhalation exposure to hydrochloric acid is associated with irritation of mucous membranes, inflammation, and fluid accumulation in the lungs. 
	We welcome comments and suggestions related the interactions of this proposed NESHAP and other regulatory requirements in the context of the sector-based considerations described above.
      
I.	Other Changes and Areas Where We are Requesting Comment
Startup, Shutdown and Malfunction.  The
       Court of Appeals for the District of Columbia Circuit recently vacated EPA's rules exempting major sources from otherwise applicable emission standards during periods of startup, shutdown and malfunction.  Sierra Club v. EPA, F.3d (2008).  A consequence is that 
      EPA must develop section 112(d) standards for these operating conditions for previously-exempted major sources.  Portland cement kilns are among these previously-exempted source categories.  For purposes of this proposed rule, this means that that these sources must now either meet generally applicable emission standards at all times, or EPA must develop section 112 (d) standards for cement kilns when operating under startup, shutdown or malfunction conditions.  
      EPA is not now at a point where it can propose quantitative standards for cement kilns operating in startup, shutdown and malfunction modes.  Accordingly, the Agency solicits comment, including available data, addressing this issue.  In addition, there is likely to be a difference in standards depending on which of the modes is at issue.  Startup
       and shutdown are both somewhat controlled operating modes for cement kilns (although occurring over different time periods), though we believe that shutdowns can vary (planned or emergency) and startups can be from a cold or a hot kiln.  Malfunction conditions are (by definition) unanticipated occurrences for which control strategies are mainly reactive.  EPA thus
       requests that commenters differentiate among the five operating modes in addressing this issue.  EPA notes further that it may notice data received on this issue for further public comment as part of this rulemaking.	
	Data used to set existing source floors.  The emissions standards included in the proposed rule were calculated using the emissions information available to the Administrator, in accordance with EPA's interpretation of the requirements of section 112(d)(3) of the Act.  In developing this proposed rule, we specifically sought data from as many kilns as possible given the time constraints when we began our data collection process.  Given that there are 152 kilns in this source category, the 12 percent representing the best performing kilns would be 19 kilns.  However, in some cases we have emission data from as few as 12 cement kilns, which means that existing source floors were proposed using as few as 2 kilns (although we are soliciting comment on an alternative interpretation that would allow EPA to base floors on a minimum of five sources' performance in all instances where those data exist.  EPA knows that more emissions information from other kilns, both with and without similar process and control characteristics, would lead to a better characterization of emissions from the entire population of cement kilns, as well as a better description of intra-source, inter-source, and test method variability, and that statistical techniques can be employed to provide the expected distribution of emissions for the cement kiln population.  EPA thus requests commenters to provide additional emissions information on cement kilns' performance.     
	HCl Test Data and Methods.  In some instances, the emissions standards included in the proposed rule were calculated using emissions information provided to EPA that appears to be below detection levels established more than 15 years ago.  More specifically, Method 321 identifies a practical lower quantification range for hydrogen chloride from 1000 to 5000 parts per billion for a specific path length and test conditions.  Many of the best performing sources with respect to HCl emissions report both values and detection levels below 1000 parts per billion.  While it is not surprising that detection levels should decrease as improvements in analytical methods occur over time, EPA does not have the emissions information and other data necessary to assess independently the new, lower detection levels, some as low as 20 parts per billion.     
	Without additional data or detection limit calculations, EPA could maintain the old detection limit, accept the source-provided limit, or modify the source-provided limit to an expected new acceptable level.  Selection of an appropriate detection limit is no trivial matter, as the detection limit could impact how the available data would be used in average emissions calculations.  EPA could choose not to use any data below the detection limit in calculations.  EPA could also choose to set all data below the detection limit at a value corresponding to one-half the detection limit for average calculation purposes, reasoning that any amount of emissions between zero and the detection limit could occur when the detection limit is recorded.  Indeed, this approach, setting all data below the detection limit at a value corresponding to one-half the detection limit, was chosen by the sources that provided emissions information to EPA.  EPA could also set all data below the detection limit at a value corresponding to the detection limit, or to zero, for average calculation purposes.  Finally, EPA could apply statistical techniques to available emissions information both above and below the detection limit to provide the expected distribution of HCl emissions for the cement kiln population.  A further issue, with any of these possible approaches, would be to assess sources' operating variability.
	EPA based the HCl emissions limitations contained in the proposal using the source-provided detection limits and setting all data below the detection limit at a value corresponding to one-half the detection limit for average calculation purposes.  This approach is consistent with the emissions information supplied by sources to EPA.  See also Rybachek v. EPA, 904 F. 2d 1276, 1296 (9[th] Cir. 1990)(upholding use of this approach in setting technology-based Clean Water Act effluent limitation guideline standards).  Should EPA receive additional emissions information sufficient to calculate detection limits from already-received data or emissions information including detection limit calculations from other sources, EPA would be able to ascertain and revise, if necessary, the new detection limits and to calculate a different HCl standard.
	EPA requests additional HCl emissions information, including such information as needed to calculate detection limits, as well as detection limit calculations.  Moreover, EPA requests comments on which way, if any, to set the emission detection limit and to handle emissions information below the detection limit are suitable for use in this proceeding.  For those commenters who believe EPA's proposed emission detection limit and process to handle values below the detection limit may not be suitable, EPA requests commenters to provide their views of acceptable detection limits and processes that use values below the detection limits to calculate averages, as well as examples of sample calculations using those processes.  We are also requesting comment on the same issues relating to the use of a CEMS meeting the requirements of PS-15 to measure HCl emissions.

	

	Submission of Emissions Test Results to EPA.  Compliance test data are necessary for many purposes including compliance determinations, development of emission factors, and determining annual emission rates.  EPA has found it burdensome and time consuming to collect emission test data because of varied locations for data storage and varied data storage methods.
      One improvement that has occurred in recent years is the availability of stack test reports in electronic format as a replacement for burdensome paper copies.
	In this action, we are taking a step to improve data accessibility for stack tests (and in the future continuous monitoring data).  Portland cement sources will have the option of submitting to WebFIRE (an EPA electronic data base), an electronic copy of annual stack test as well as process data.  Data entry requires only access to the Internet and is expected to be completed by the stack testing company as part of the work that they are contracted to perform.  This option would become available as of December 31, 2011.
	Please note that the proposed option to submit source test data electronically to EPA would not require any additional performance testing.  In addition, when a facility elects to submit performance test data to WebFIRE, there would be no additional requirements for data compilation; instead, we believe industry would greatly benefit from improved emissions factors, fewer information requests, and better regulation development as discussed below.  Because the information that would be reported is already required in the existing test methods and is necessary to evaluate the conformance to the test method, facilities would already be collecting and compiling these data.  One major advantage of electing to submit source test data through the Electronic Reporting Tool (ERT), which was developed with input from stack testing companies (who already collect and compile performance test data electronically), is that it would provide a standardized method to compile and store all the documentation required by this proposed rule.  Another important benefit of submitting these data to EPA at the time the source test is conducted is that it will substantially reduce the effort involved in data collection activities in the future. Specifically, because EPA would already have adequate source category data to conduct residual risk assessments or technology reviews, there would be fewer data collection requests (e.g., section 114 letters).  This results in a reduced burden on both affected facilities (in terms of reduced manpower to respond to data collection requests) and EPA (in terms of preparing and distributing data collection requests).  Finally, another benefit of electing to submit these data to WebFIRE electronically is that these data will greatly improve the overall quality of the existing and new emissions factors by supplementing the pool of emissions test data upon which the emission factor is based and by ensuring that data are more representative of current industry operational procedures.  A common complaint we hear from industry and regulators is that emissions factors are out-dated or not representative of a particular source category. Receiving most performance test results would ensure that emissions factors are updated and more accurate.  In summary, receiving these test data already collected for other purposes and using them in the emissions factors development program will save industry, State/local/tribal agencies, and EPA time and money.
	As mentioned earlier, the electronic data base that will be used is EPA's WebFIRE, which is a Web site accessible through EPA's TTN. The WebFIRE Web site was constructed to store emissions test data for use in developing emission factors. A description of the WebFIRE data base can be found at http://cfpub.epa.gov/ oarweb/index.cfm?action=fire.main.  The ERT will be able to transmit the electronic report through EPA's Central Data Exchange (CDX) network for storage in the WebFIRE data base.  Although ERT is not the only electronic interface that can be used to submit source test data to the CDX for entry into WebFIRE, it makes submittal of data very straightforward and easy.  A description of the ERT can be found at http://www.epa.gov/ttn/chief/ert/ ert_tool.html.  The ERT can be used to document the conduct of stack tests data for various pollutants including PM (EPA Method 5 of appendix A - 3), Mercury (EPA Method 29 of appendix A - 8), and HCl (EPA Method 321 of appendix A - 8).  Presently, the ERT does not handle dioxin/furan stack test data (EPA Method 23 of appendix A - 7), but the tool is being upgraded to handle dioxin/furan stack test data.  The ERT does not currently accept opacity data or CEMS data.
	EPA specifically requests comment on the utility of this electronic reporting option and the burden that owners and operators of portland cement facilities estimate would be associated with this option.
	Definition of affected source.  In the final amendments published on December 20, 2006, we indicated that we were changing paragraph (c) in §63.1340 to clarify that crushers were part of the affected source for this rule (71 FR 76532).  However, we omitted the rule language changes to that paragraph.  This language has been added to this proposed rule.
V.  Summary of Comments and Responses on Notice of Reconsideration and EPA Final Action in Response to Remand
	This section presents a summary of 
	comments received on the final action published on December 20, 2006.  
	We are not responding to these comments in this proposed action.  We will provide responses to these comments, and other comments received on these proposed amendments, when we take final action on this proposal.   
A.  Petition to Withdraw Final Standards
	Commment:  One commenter petitioned EPA to withdraw the new source standards for mercury and THC, as well as the provision in §63.1344(i) concerning the allowable CKD recycle rate because of procedural defects and the lack of record support.  Several commenters agree that EPA should withdraw the standards for the same reasons given in the petition.
	The commenter stated that the proposed rule was silent on the possibility of issuing a new source standard for mercury based on a wet scrubber, a new source standard for THC based on an RTO, and the operating limit for new and reconstructed kilns in §63.1344(i).  EPA violated CAA section 307(d)(3) and (d)(5) by not proposing these requirements and not providing an opportunity for comment.  The commenter also alleged that comments filed by the public did not lead EPA to the positions taken in the final rule.  Therefore, EPA cannot argue that the final standards represent a "logical outgrowth" of the proposal. 
	EPA application of the reconsideration process does not cure these defects.  EPA lacks authority to initiate reconsideration on its own through CAA section 307(d)(7)(B); this provision clearly is designed for a process in response to request by another person.  There appears to be no precedent for this action and EPA did not cite any precedent.  
	The commenter also argued that the standards lack record support and are therefore arbitrary and capricious under CAA section 307(d)(9)(A).  EPA conceded in the final rule and notice of reconsideration that it was unclear whether the new source standards for mercury and THC are "achievable" or appropriate (see pages 12-14).  For the provision concerning the CKD recycle rate, EPA provided no explanation as to whether it was possible to continually "not exceed the average hourly CKD recycle rate during mercury performance testing" or whether any cement kiln has achieved this result in practice.  Because EPA did not point to any "best controlled" existing source that has achieved such a recycle rate, the provision violates the MACT floor requirements for new sources in CAA section 112(d)(3).  EPA in effect promulgated a beyond the floor standard without considering the required criteria (including costs) in CAA section 112(d)(2).  EPA also did not demonstrate that the requirement is achievable, did not provide a "statement of basis and purpose" for the requirement, or an explanation of the reasons for changes from the proposal in this regard, as required by CAA section 307(d)(6)(A).
  	According to the commenter, EPA's promulgation of these standards, coupled with the notice for reconsideration, has created significant uncertainty and will require construction delays until the issues are resolved or installation of the technologies regardless of whether they are necessary; either will result in financial harm to several companies.     
B.  Petition to Reconsider Final Standards  	
	One commenter petitioned EPA to reconsider the work practice standards for mercury and THC, the decision not to set standards for HCl, and the decisions not to set beyond-the-floor standards for mercury and THC.
	Comment:  The commenter argued that the work practice standards for mercury and THC are unlawful.  The D.C. Circuit Court remanded the cement kiln rule with instructions to set MACT floor standards for HCl, mercury, and THC.  However, EPA set work practice standards instead of emission standards.  The commenter asserted that the work practice standards are not and do not purport to be emission standards.  The CAA makes it entirely clear that for the purpose of section 112, a work practice standard is not an emission standard.  Section 112(h) provides that "if it is not feasible ... to prescribe or enforce an emission standard for the control of a hazardous air pollutant or pollutants, the agency may in lieu thereof, promulgate a design, equipment, work practice, or operational standard . . ."  The clarity of section 112 on this point is not diminished by section 302(k)'s definition of "emission standard" to include a work practice standard.  Section 112(h) is the more specific provision with respect to section 112 standards.  Reading "emission standard" to include work practice standards would nullify the distinction that section 112(h) draws between the two, and essentially render section 112(h) meaningless and surplus.  Because the only requirements EPA established for emissions of mercury and THC from existing kilns are work practice standards rather than emission standards, the final rule violates National Lime's mandate to set emission standards.  The commenter also argues that the work practice standards, if they could be viewed as emission standards, do not satisfy the MACT floor requirements in section 112(d)(3); EPA did not purport the work practices reflect the relevant best sources' emission levels or the best performing 12 percent of kilns, which EPA has never identified.  The commenter also stated that the work practices do not satisfy section 112(h) because EPA did not claim that was not feasible to prescribe or enforce an emission standard for either pollutant.  EPA could not make this claim because both pollutants are emitted from kiln stacks and it is technologically or economically impractical to measure the emissions.
	Comment:  The commenter alleges that EPA's refusal to set any emission standards for HCl is unlawful.  The commenter claimed that section 112(d)(4), which EPA cited as its authority for declining to set emission standards for HCl, does not excuse EPA from setting standards for a pollutant but merely provides that it is there as an established health threshold for a pollutant, EPA may consider that threshold, with an ample margin of safety when establishing emission standards.  According to the commenter, EPA confirmed that it did not know whether or not HCl causes cancer.  Because EPA does not know whether HCl is carcinogenic, EPA has not identified a health threshold below which HCl does not cause cancer.  Therefore, EPA can not invoke section 112(d)(4) with respect to HCl.  The commenter also stated that EPA's attempts to rely on its statements about HCl in previous rules are unfounded.  The 1998 rule on which EPA primarily relies classified HCl as a Group D pollutant (one for which EPA lacks data about carcinogenicity).  Classification of a pollutant in Group D merely underscores that EPA cannot support a finding that a pollutant is a threshold pollutant with respect to cancer.  In addition, the 1998 rule made the Group D classification only for the purposes of that rule and not for any other actions.
The commenter also pointed out that EPA has not identified a threshold for non-cancer effects.  The threshold EPA claimed to have identified as the reference dose concentration (RfC), i.e., the long term threshold, must be a level below which no adverse health effects occur.  The level that EPA claims is a threshold does not meet this requirement because it was based on a single animal study which used only one dose, looked only at respiratory effects, not effects on other bodily systems, and identified only a lowest observed adverse effects level at which adverse effects did occur, not a threshold at which adverse effects do not occur.  The commenter stated that EPA effectively acknowledged that exposure to HCl does damage people's heath (71 FR 76542).  Congress intended EPA to apply section 112(d)(4) where there is no risk of adverse health effects.  Tissue damage is an adverse health effect.
The commenter stated that EPA's reliance on a risk assessment prepared by an industry trade association is unlawful and arbitrary.  The record does not show any attempt to verify the data, methodology, or results and the analysis gives no indication when the data was obtained, whether it reflects ongoing conditions, whether it accounts for potential emissions and modifications, whether the assumptions and emissions levels in the analysis are representative, or why one-third of the plants are not included.  The commenter also argued that analysis did not adequately show that HCl emissions from the kilns covered by study are below the RfC.  According to the commenter, the analysis uses default rather than kiln-specific data for all but one variable to estimate HCl emissions and concentrations.  Even if the study showed conclusively that HCl levels were at or below the RfC, the absence of data and mischaracterization of background levels prevents EPA from showing that it has provided an ample margin of safety as required by CAA section 112(d)(4).  According to the commenter, the analysis mischaracterized background emissions and provides no reason to believe that HCl background levels in areas where kilns operate is not higher or that background levels have not increased compared to 1996 and 1999 values, does not account for variability, and does not adequately account for co-location of industrial facilities.  The analysis of background levels for short-term hazard quotient is similarly flawed.  The commenter also criticized the application of a rural parameter to all kilns, which is not the case for many kilns.
Section 112(d)(4) also requires that the standards do not have any adverse environmental effects.  No ecological assessment was conducted for the analysis or by EPA.  In fact, the analysis does not even claim there would be no impacts, only that any deleterious effects were likely to be localized rather than widespread.    
	Comment:  The commenter criticized EPA's beyond-the-floor determination for mercury emissions.  According to the commenter, EPA conducted beyond-the-floor analyses for all "demonstrated" control techniques excluding all of the techniques raised in public comments except for ACI and wet scrubbers.  EPA's claim that it can ignore technologies if the Agency does not believe that they are "demonstrated control techniques for the cement industry" is unlawful.  Section 112(d)(2) requires beyond-the-floor standards to reflect the maximum degree of reduction that is achievable through the full range of potential reduction measures.  There is no precondition that control technologies must be demonstrated in the industry to be regulated.
	EPA's rejection of ACI as not cost-effective based on new cost estimates is unlawful and arbitrary for all the reasons given in comments on the proposed rule.  EPA's rejection of ACI is also unlawful and arbitrary because:  (1)  EPA alludes to increased energy use but does not say what increase would occur and why that justifies rejection of ACI; and (2)  EPA alludes to increased solid waste generation, but does not say why the specific amount generated weighs against beyond-the-floor standards or why it is preferable for mercury to be emitted to the air rather than contained in solid waste.  The Agency must explain the relevance of a specific statutory factor to beyond the floor analysis and how consideration of that factor supports its conclusion.
	Although EPA acknowledged that ACI reduces THC, the cost effectiveness analysis remains arbitrary because EPA never determined the cost effectiveness of ACI with respect to all the HAP it controls (including polychlorinated biphenyls, polycyclic organic matter, and benzene).  Further, the analysis mistakenly assumes that the same ACI device would have to be purchased separately with respect to each HAP, when the device is a single investment that would reduce many pollutants.  In addition, EPA did not explain why it considers the amount of THC that would be reduced as "small" (30 to 117 tpy per kiln is significant) or why such a reduction is not justified.  Finally, EPA's claim that it can reject a beyond-the-floor measure, not because the measure is not "achievable", but because it does not view the cost as "justified" is unlawful for the reasons given in previous comments.
	Comment:  EPA's rejection of a beyond-the-floor standard banning the use of utility boiler fly ash where such use increases mercury emissions is unlawful and arbitrary.  EPA claims that this measure is not "justified" because of cost, energy, and non-air environmental impacts.  The CAA requires EPA to set final standards reflecting the maximum degree of reduction that is "achievable" considering costs and other factors, not the degree of reduction that EPA thinks is "justified" in light of those factors.  And, because EPA admitted that it did not know what the costs of this measure would be, reliance on cost arguments to reject the provision is arbitrary.  Also arbitrary is EPA's reliance on non-air impacts (the increased amount of utility boiler ash that would have to be otherwise disposed of).  EPA did not explain why:  (1)  the need for utility boilers to dispose of their ash would be a worse problem than the release to the air of the mercury contained in the ash; (2) all the ash that is currently used in kilns would require disposal when it can be used in concrete without going to the kiln; (3)  kilns that are currently using fly ash would have to use raw materials if the use of fly ash that increases mercury emissions were banned; (4)  the undetermined amount of mining necessary for an undetermined number of kilns that had to stop using any fly ash would be a worse problem than the mercury emissions that result from the use of the fly ash such that the concern about additional mining weighs against the beyond the floor measure.  EPA also cites energy concerns as a reason for rejecting the beyond the floor measure but does not identify or explain them. 
Comment:  The commenter criticized EPA's beyond-the-floor determination for THC emissions.  EPA rejected beyond-the-floor standards based on ACI and wet scrubbers combined with RTO (scrubber/RTO) based on the costs per ton of THC removed and organic HAP removed and alleged concerns about increased energy use and adverse non-air quality health and environmental impacts.  EPA also rejected optimized combustion practices because it lacks the data to evaluate reductions and the use of a carbon coke system because the Agency considered scrubber/RTO and therefore does not have to consider other options that are not already in use in this country.  EPA's claim that it can reject a beyond-the-floor measure not because it has determined that the measure is not "achievable" but because the cost is not justified is unlawful for the reasons given in comments on the proposed rule.  Further, EPA's contention that beyond-the-floor standards based on ACI and scrubber/RTO would not be justified on cost grounds is not explained.  The cost of reducing THC as a surrogate for all the non-dioxin organic HAP from the kilns is reasonable and well within the ranges EPA has found acceptable for other rules.  EPA can not look past the cost of the THC reduction as the reason for rejecting the measure.  If THC is not a valid surrogate, EPA should find a different surrogate or establish separate limits for each pollutant.  It is arbitrary to choose a surrogate for some purposes but not others.  In addition, EPA cost effectiveness estimates for organic HAP are unexplained, unsupported by the record, and arbitrary.  EPA did not explain its assumption that organic HAP comprise 5 percent of the THC, which organic HAP it is counting, or the quantity of emissions from these HAP.  In addition, determining the cost effectiveness of all non-dioxin organic HAP on a single cost per ton basis is not warranted because these HAP emissions vary in quantity and toxicity.  EPA also does not provide any basis for its arguments about energy use and solid waste or why these impacts make the beyond the floor measure either unachievable (the statutory standard) or unjustified (EPA's preferred standard).
	EPA's rejection of optimized combustion controls is arbitrary and unlawful.  According to the commenter, EPA argues that it does not even have to consider potential reduction measures if it does not already have data for them.  EPA cannot frustrate section 112(d)(2) requirements by declining to collect information.  Congress required the maximum degree of reduction that is achievable through all potential reduction measures, not the maximum degree of reduction achievable through measures for which the Agency deigns to collection information.
	EPA's rejection of carbon coke technology is arbitrary because the Agency provided no rationale basis for its conclusion.  EPA rejected carbon coke technology because it is used by a kiln in another country.  No language in the CAA suggests that EPA may refuse to consider a technology because it is not already in use in this country or because the Agency has considered some other technology. 
C.  New Source MACT for Mercury Emissions and Related Requirements
Comment:  One commenter states that new cement kilns are not likely to install wet scrubbers in areas where the raw materials are low in sulfides.  The commenter recommends that EPA include an alternative standard for new kilns that allows the owner or operator to average mercury emissions over all modes of the raw mill operation on a monthly basis to achieve the same limit in the final rule.
	Comment:  One commenter explained that a 3 to 9 hour stack test on a cement kiln cannot provide an accurate or representative estimate of long-term mercury emissions.  The rate of mercury emissions from a modern precalciner kiln is constantly changing.  Even a 1 week test can not provide a representative picture of long-term (1 year) mercury emissions from these systems.
Comment:  One commenter asks that EPA require more representative mercury monitoring such as the periodic use of EPA Method 324 (Sorbent Trap) or mercury CEMS at all cement kilns based on their mercury emission profiles and raw material practices.
Comment:  One commenter points to high mercury emissions in 2004 with reduced emissions in 2005 from one cement plant in California and one cement plant in Oregon based on the most recent toxic release inventory submittals.  The commenter asks EPA how mercury was reduced at these sites in 2005 and how they will be reduced at these sites in the future and for EPA to determine whether the concepts used by the plants can be used in more kilns.
	Comment:  One commenter pointed out that mercury emissions from cement plants are higher than the entire mercury budgets for future coal-fired power plants emissions in numerous States.  The revisions made after reconsideration must be at least as stringent as the December 2006 final rule.  Another commenter states that EPA has not effectively controlled mercury emissions from cement kilns; new and existing kilns should have the most stringent requirements.
D.  New Source MACT for THC Emissions and Related Requirements
	Comment:  One commenter objected to the MACT floor for new kilns based on the single application of a wet scrubber and RTO.  According to the commenter, EPA stated that two facilities have attempted to use the technology; at one facility the systems did not operate continuously due to significant operational problems caused by the site specific constituents in the flue gas but the technology operates continuously and effectively at the second facility.  The commenter claimed that the standard is based on a technology that has not been demonstrated to work in all applications.  In addition, the technology at the second facility has not worked continuously and effectively as EPA claimed.  According to the commenter, the technology has experienced operational and maintenance problems at both facilities.  The commenter stated that EPA's evaluation of the MACT floor is flawed and should be reevaluated. 
	Comment:  Some commenters disagreed with EPA's cost estimates for wet scrubber/RTO technology.  One commenter stated that the capital costs at the two facilities referenced by EPA for a 1 million tpy kiln are $18 to $25 million for wet scrubbers and $15 to $20 million for RTO compared to EPA's estimate of $10.7 million.
	One commenter stated that requiring the wet scrubber/RTO technologies for new sources may make new construction economically infeasible and that neither the wet scrubbing nor RTO technologies have been required based on permitting/new source review requirements.  Another commenter stated that the new source MACT requirements for THC (wet scrubber/RTO) will have a negative impact on the local watershed which can not afford the additional 58.5 million gallons of water per year for a wet scrubber.  
	Comment:  One commenter alleges that EPA's statement on consultation with Indian Tribes (no tribes were consulted about the rule because it would have no impact on them) is inaccurate because the commenter is constructing a new source on the Moapa Pauite Indian Reservation.
E.  Cement Kiln Dust Requirements
	Comment:  One commenter said the CKD provision in §63.1344(h) is unworkable because it codifies as "static" a practice that varies from plant to plant.  The primary purpose of removing CKD from the kiln system is to manage the concentration of alkali compounds in the clinker and subsequent cement.  The amount of CKD removed varies according to the chemistry of the raw material feed.  In addition, alkali specifications have changed as a result of State requirements, resulting in changes in the amount of CKD removed.  And, plants that use a preheater/precalciner design do not remove CKD from the kiln system (and the material is not considered to be generated at these plants) while other plants using long dry or long wet technology remove CKD from the system but return it as a component of the raw material mix.  Another commenter explained that removing CKD from the kiln system recycling loop is critical to the efficient control of mercury emissions.
	Another commenter stated that the CKD provision, as written, could be interpreted to require removal of CKD from the system.  Unnecessary removal would create a new solid waste problem and reduced the energy efficiency of the process if the amount of raw materials going into the process had to increase as a result of the CKD being removed.
	Finally one commenter requests that EPA clarify the CKD provision for existing sources in §63.1344(h).  EPA explained in the preamble that a facility must remove CKD from the system "at the point product quality is adversely affected."  The comment asks whether "the point" is a point in time, point in the cement manufacturing process, or point on the continuum of cement product chemistry.  Also, what "product quality" standard is meant (i.e., ASTM, American Association of State Highway Transportation Officials, ANSI, or another standards organization)?  Is there a need for different compliance approaches to suit the various types of cement (e.g., Type 1, Type V) produced by an individual facility?
F.  Fly Ash Requirements
	Comment:  Some commenters urged EPA to stand by its decision not to ban all fly ash but object to the fly ash provision as promulgated.  According to the commenters, the ban could result in increased landfilling of the ash.  The prohibition was adopted without proper notice and comment and EPA adopted the ban based on consultations with one industry sector without discussing it with the sector most affected (coal burning power industry).  The commenters also disagreed with EPA's explanation that the fly ash prohibition could be imposed without any immediate impacts because utilities will not be installing ACI or other forms of sorbent injection until at least 2010.  The commenters believed that adverse effects are likely as early as 2007 when plants begin testing or plants must comply with State regulations.
	The commenters stated the prohibition was inflexible because it does not allow for exceptions regardless of the emission control technologies used at the kiln.  If there is justification for a ban on the use of mercury-enhanced fly ash in kilns with no controls, EPA failed to address the need for a ban at kilns with controls (i.e., wet scrubbers, ACI, fabric filters).  The provision allowing the kiln to demonstrate that the fly ash will not increase mercury emissions over baseline levels puts the burden and cost of testing the emissions on the cement plant.  The cement plant could easily avoid the burden by using alternative feedstock, possibly with higher mercury concentrations.  It is unrealistic to expect the cement industry to spend resources on the testing especially if the kiln already has emission controls and no testing requirements apply to any other feedstock.  EPA should amend §63.1344(g) to exclude plants already subject to a mercury standard as follows:
      No kiln and in-line kiln/raw mill may use as a raw material or fuel any fly ash where the mercury content of the fly ash has been increased through the use of activated carbon, or any other sorbent if it will result in an increase of mercury input to the process unless the facility desiring to use the fly ash is already subject to a mercury standard (either an emission or input limitation) or unless the facility can demonstrate that the use of that fly ash will not result in an increase in mercury emissions over baseline emissions (i.e., emissions not using the fly ash).  The facility has the burden of providing there has been no emissions increase over baseline.
      
This change would allow kilns that have installed emission controls to rely on them without additional testing, demonstrations, or certifications and would not penalize one feedstock from one industry sectors while favoring other feedstocks that may contain higher mercury concentrations.
Comment:  One commenter pointed out that the final rule includes a ban only on fly ash derived from power plants that use ACI to reduce mercury emissions.  The commenter recommends that EPA expand the scope of the limited fly ash ban to address high loss on ignition (LOI) or selective catalytic reduction (SCR)-affected fly ash laden with mercury.  Such fly ash should be treated in a like manner to ash containing activated carbon.  Expanded mercury measurement and removal strategies should be incorporated if use of such fly ash is allowed at cement plants.  The commenter provides information explaining how fly ash can become enriched with mercury due to combustion controls for nitrogen oxide (NOX) (i.e., low NOX burners, separate overfire air, reburn) and SCR.  High emissions of mercury may result from power plant fly ash where ACI is not used to control mercury emissions.
Another commenter stated that cement kilns combusting fly ash containing higher LOI fly ash after the ash has been beneficiated generally by electrostatic separation can emit higher levels of mercury.  Cement kilns are currently burning beneficiated high LOI fly ash.  Re-use of higher LOI beneficiated fly ash through combustion in cement kilns should be further evaluated.
	Comment:  One commenter objected to EPA's assumption that the TOXECON system (which collects fly ash before sorbents are injected) will work for all power plants and be economically feasible; this technology has not be tested on medium and high sulfur bituminous coal and may not be effective.  The commenter disagreed with EPA's statement in the preamble that "technology is being developed that would allow the mineral-rich portion of the fly ash to be separated from the high carbon/high mercury portion."  According to the commenter, the record does not identify these technologies by name or documents the cost.  The commenter is aware of fly ash beneficiation technologies that remove carbon from fly ash so it can be used in concrete, but it is unclear whether these technologies can remove activated carbon containing adsorbed mercury.
Comment:  Two commenters stated that the certification requirements for fly ash contaminated by activated carbon are too burdensome.  The commenters objected to the requirement in §63.1344(o) for facilities to obtain from the fly ash supplier a certification for each shipment of fly ash.  The amount of fly ash used varies considerably, but some plants receive numerous shipments on a daily basis.  The commenters recommend that the rule require each supplier to provide an initial certification confirming that the fly ash does not contain activated carbon used to capture mercury.  A new certification could be required annually or if the treatment method was changed.   
G.  Compliance Dates for Cement Kiln Dust and Fly Ash Provisions
	Comment:  Several commenters asked EPA to clarify the compliance dates for the CKD recycle rate provision for existing sources in §63.1344(h), the CKD recycle rate provision for new and reconstructed sources in §63.1344(i), and the provision on fly ash use in §63.1344(g).  The commenters recommend that EPA allow 1 year to comply with the fly ash provision for existing sources in §63.1344(g) and CKD recycle rate provision for existing sources in §63.1344(h).  That would make the compliance dates for these requirements consistent with the compliance date for existing sources to meet the THC good combustion practices (December 20, 2007) in §63.1351(c).
	One commenter asks that EPA revise the compliance date for the CKD recycle rate provision for new and reconstructed kilns in §63.1344(i).  Since EPA never proposed the provision, the final rule is more stringent than the proposal and sources commencing construction between December 2, 2005, and December 20, 2006, should be given 3 years to comply.
H.  Research and Technology
	Comment:  One commenter requests EPA to conduct further research on the concept of bypassing mercury-enriched dust from PM control devices or raw meal to clinker product.  ASTM and ASSHTO now allow intergrinding of 5 percent limestone with clinker to make Type I cement product.  Type II cement can have any greater amounts of other constituents.  There is the possibility that some dust or meal can be used to substitute milled clinker without harming the quality of the product.  Some plants may be able to use this approach to bleed mercury from the process.
	Comment:  One commenter, an ash management company, is investing in beneficiation technology with the goal of utilization of the fly ash as is done now in Europe.  This commenter asked EPA to assemble a technical record on the effects and uses of sorbents (and other approaches) to facilitate increased utilization.
	Comment:  One commenter identified SCR as an add-on control that can reduce THC and dioxins/furans (D/F) and convert mercury in the cement process into more collectible forms for subsequent bypass strategies.  Two other commercially available strategies rely on catalysts to reduce NOX, THC, or D/F.  One proven technology reacts ammonia with NOX in the presence of a catalyst with concurrent D/F and THC destruction.  The second uses catalytic material fibers that are woven and layered with standard baghouse fabric such that both the catalytic destruction of D/F and particulate control are achieved.  The fabric filter technology is described at www.environment.power.alstom.com/home/ by following the links to Industry Solutions/Products/Fabric Filters/Remedia Filter Bags.  EPA should review the role of SCR at some kilns as a THC and D/F control strategy in its reconsideration of the final rule.  SCR and catalytic fabric filters should be considered in EPA's multi-pollutant evaluation of the cement industry.
VI.  Summary of Cost, Environmental, Energy, and Economic 

Impacts of Proposed Amendments
 
A.  What are the affected sources?
   
	There are currently 93 portland cement manufacturing facilities located in the U.S. and Puerto Rico that we expect to be affected by these proposed amendments.  In 2005, these facilities operated 152 cement kilns and associated clinker coolers.  We have no estimate of the number of raw material dryers that are separate from the kilns.
	Based on capacity expansion data provided by the Portland Cement Association, we anticipate that 20 new kilns and associated clinker coolers will be built in the five years after the promulgation of final standards representing 24 million tpy of clinker capacity.  Some of these new kilns will be built at existing facilities and some at new greenfield facilities.  The location of the kiln (greenfield or currently existing facility) has no bearing on our estimated cost and environmental impacts.  	We based new kiln impacts on a 1.2 million tpy clinker kiln.  This kiln is the smallest size anticipated for new kilns based on kilns built in the last five years or currently under construction.  Using the smallest anticipated kiln size provides a conservative estimate of costs because control costs per unit of capacity tend to be higher for smaller kilns.
B.  How are the impacts for this proposal evaluated?
	For these proposed Portland Cement NESHAP amendments, the EPA utilized three models to evaluate the impacts of the regulation on the industry and the economy.  Typically in a regulatory analysis, EPA determines the regulatory options suitable to meet statutory obligations under the CAA.  Based on the stringency of those options, EPA then determines the control technologies and monitoring requirements that may be selected to comply with the regulation. This is conducted in an Engineering Analysis.  The selected control technologies and monitoring requirements are then evaluated in a cost model to determine the total annualized control costs.  The annualized control costs serve as inputs to an Economic Impact Analysis model that evaluates the impacts of those costs on the industry and society as a whole.  
      The Economic Impact Analysis model uses a single-period static partial-equilibrium model to compare a pre-policy cement market baseline with expected post-policy outcomes in cement markets. This model was used in previous EPA analyses of the portland cement industry (EPA, 1998; EPA, 1999b).  The benchmark time horizon for the analysis is assumed to be short and producers have some constraints on their flexibility to adjust factors of production. This time horizon allows us to capture important transitory impacts of the program on existing producers. The model uses traditional engineering costs analysis as "exogenous" inputs (i.e., determined outside of the economic model) and computes the associated economic impacts of the proposed regulation.
      For the Portland Cement NESHAP, EPA also employs the Industrial Sector Integrated Solutions (ISIS) model which conducts both the engineering cost analysis and the economic analysis in a single modeling system.  The ISIS model is a dynamic and integrated model that simulates potential decisions made in the cement industry to meet an environmental policy under a regulatory scenario.  ISIS simultaneously estimates 1) optimal industry operation to meet the demand and emission reduction requirements, 2) the suite of control technologies needed to meet the emission limit, 3) the engineering cost of controls, and 4) economic impacts of demand response of the policy, in an iterative loop until the system achieves the optimal solution.  More information on this model can be found in the ISIS Technical Support Document (TSD).  The peer review of the ISIS model will be available at http://www.epa.gov/ttn at a future date.   
      In a Technical Memo to the docket, we provide a comparison of these models to provide an evaluation of how the differences between the models may impact the resulting estimates of the impacts of the regulation.  For example, the Engineering Analysis and Economic Impact Analysis evaluate a snapshot of implementation of the proposed rule in a given year (i.e., 2018, based on 2005 dollars) while ISIS evaluates impacts of compliance dynamically over time (i.e., 2013-2018).  In general, given the optimization nature of ISIS, ISIS accounts for more flexibility when estimating the impacts of the regulation. For example, when optimizing to meet an emission limit, ISIS allows for the addition of new kilns, as well as kiln retirements, replacements, and expansions and the installation of controls.  In the Engineering Analysis the existing kiln population is assumed to be constant even though normal kiln retirements occur. Overall, we anticipate the total control costs from the Engineering Analysis to be higher than that of ISIS.  With higher cost estimates serving as the basis for the Economic Impact Analysis along with other modeling differences, we expect the results presented from the EIA model will be higher in impact than those presented by ISIS.  
      In addition, we have not yet developed ISIS modules to calculate non-air environmental impacts and energy impacts.  Therefore, these sections only contain impacts calculated by the traditional engineering methods  
C.   What are the air quality impacts?

For the proposed Portland Cement NESHAP, EPA estimated the emission reductions	that would occur due to the implementation of the proposed emission limits.  EPA estimated emission reductions based on the control technologies selected by the engineering analysis.  These emission reductions are based on 2005 emission baselines.
Under the proposed limit for mercury, we have estimated that the emissions reductions would be 13,400 lb/yr for existing kilns. Based on our 1.2 million tpy model kiln, mercury emissions would be reduced by 149 lb/yr for each new kiln, or about 3,000 lb/yr 5 years after promulgation of the final standards.
Under the proposed limits for THC, we have estimated that the emissions reductions would be 14,000 tpy for existing kilns, which represent an organic HAP reduction of 3,360 tpy.  For new kilns, THC emissions would be reduced by 39 tpy per kiln or about 800 tpy 5 years after promulgation of the final standard.  This represents an organic HAP reduction of 192 tpy.
Under the proposed limit for HCl, we have estimated that emissions would be reduced by 3,000 tpy for existing kilns. Emissions of HCl from new kilns would be 45 tpy per kiln or 900 tpy 5 years after promulgation of the final standards.
The proposed emission limits for PM represent a lowering of the PM limit from 0.5 lb/ton of clinker to 0.085 lb/ton of clinker for existing kilns and for new kilns, a lowering to 0.080 lb/ton of clinker. We have estimated that PM emissions would be reduced by 10,300 tpy for existing kilns. For new kilns, emission reductions would be 160 tpy per kiln, or about 3,200 tpy 5 years after promulgation of the final standards.
The proposed standards for mercury, THC and HCl will also result in concurrent control of SO2 emissions. For kilns that 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 and to avoid plugging and fouling of the RTO. Scrubbers will also be used to control HCl and mercury emissions. Reductions in SO2 emissions associated with controls for mercury, THC and HCl are estimated at 1,600 tpy, 11,700 tpy, and 106,000 tpy, respectively. Total reduction in SO2 emissions from existing kilns would be an estimated 119,300 tpy. A new 1.2 million tpy kiln equipped with a scrubber will reduce SO2 emissions by 1,000 tpy on average or about 20,000 tpy in the fifth year after promulgation of the final standards.
These controls will also reduce emissions of secondary PM2.5 (and coarse PM  -  PM10-2.5 as well).  This is PM that results from atmospheric transformation processes of precursor gases, including SO2.
In addition to this traditional estimation of emission reductions, EPA employed the ISIS model to estimate emission reductions.  The estimation of emission reductions in the ISIS model accounts for the optimization of the industry and includes the addition of new kilns, kiln retirements, replacements, and expansions as well as installation of controls.  Using the ISIS model, in 2013 we estimate reductions of 12,000 lbs of mercury, 11,951 tons of THC, 2,791 tons of HCl, 10,554 tons of PM and 163,309 tons of SO2 compared to total emissions in 2005.  More information on the ISIS model and results can be found in the ISIS TSD and in a Technical Memo to the docket. 
D.	What are the water quality impacts?

We estimated no water quality impacts for the proposed amendments.  The requirements that might result in the use of alkaline scrubbers will produce a scrubber slurry liquid waste stream.  However, we assume the scrubber slurry produced will be dewatered and added back into the cement-making process as gypsum.  Water from the dewatering process will be recycled back to the scrubber.  The four facilities that currently use wet scrubbers in this industry report no water releases at any time.  However, if the use of scrubbers becomes more widespread there could be a potential for a water release due to system purges.  We are requesting comment on what, if any, regulations might apply, and if we should add any requirements to this rule to prevent or control these purges.  The addition of scrubbers will increase water usage by about 2,789 million gallons per year. For a new 1.2 million tpy kiln, water usage will be 36 million gallons per year or 720 million gallons per year 5 years after promulgation of the final standards.  
We note that some preproposal commenters have stated that some new and existing facilities may be located in areas where there is not sufficient water to operate a wet scrubber.  However, we are not mandating the use of wet scrubber technology in these regulations, and we believe that sufficient alternative controls exist for mercury and acid gas controls that this issue would not preclude a facility from meeting these proposed emissions limits.  However, we are also soliciting comment on this issue.  
E.	What are the solid waste impacts?

The potential for solid waste impacts are associated with greater PM control for kilns, waste generated by ACI systems and solids resulting from solids in scrubber slurry water.  As explained above, little or no solid waste is expected from the generation of scrubber slurry.  The PM captured in the kiln fabric filter (cement kiln dust) is essentially recaptured raw material, intermediate materials, or product.  Captured PM is typically recycled back to the kilns to the maximum extent possible.  We estimate that any additional PM captured would also be recycled to the kiln because facilities minimize CKD disposed of as solid waste to the minimum required to maintain product quality.  Increasing the amount of PM capture should not affect the minimum amount of PM required to be wasted.  
Where equipped with an alkali bypass, the bypass will have a separate PM control device and that PM is typically disposed of as solid waste.  An alkali bypass is not required on all kilns.  Where one is present, the amount of solid waste generated from the alkali bypass is minimal, usually about 1 percent of total CKD in control devices, because the bypass gas stream is a small percentage of total kiln exhaust gas flow and the bypass gas stream does not contact the feed stream in the raw mill.  
Waste collected in the polishing baghouse associated with ACI that might be added for mercury or THC control cannot be recycled to the kiln and would be disposed of as solid waste.  An estimated 120,400 tpy of solid waste would be generated from the use of ACI systems on existing kilns.  Each new kiln equipped with an ACI system would be expected to generate 1,800 tons of solid waste per kiln or, assuming 14 of the 20 new kilns would add ACI systems, about 25,000 tpy in the fifth year after promulgation of the final standards.
In addition to the solid waste impacts described above, these is a potential for an increase in solid waste if a facility elects to control mercury emission by increasing the amount of CKD wasted rather than returned to process.  This will be a site-specific decision, and we have no data to estimate the potential solid waste that may be generated by this practice.  However, we expect the total amount to be small for two reasons.  First, wasting cement kiln dust for mercury control represents a significant expense to a facility because they are essentially wasting either raw materials or product.  So we anticipate this option will not be used if the amount of CKD wasted would be large.  Second, we believe that cement manufacturers will add the additional CKD to the finish mill to the maximum extent possible rather then waste the material. 
 
F.	What are the secondary impacts?

Indirect or secondary air quality impacts include impacts that would result from the increased electricity usage associated with the operation of control devices as well as water quality and solid waste impacts (which were just discussed) that would occur as a result of these proposed revisions. We estimate these proposed revisions would increase emissions of criteria pollutants from utility boilers that supply electricity to the portland cement facilities. We estimate increased energy demand associated with the installation of scrubbers, ACI systems, and RTO. The increases for existing kilns are estimated to be 1,700 tpy of NOx, 800 tpy of CO, 3,000 tpy of SO2 and about 80 tpy of PM. For new kilns (assuming that of the 20 new kilns to start up in the 5 years following promulgation of the final standard 20 will add alkaline scrubbers, 2 will add an RTO, 14 will install ACI systems, and 20 will install membrane bags instead of cloth bags in their baghouses), increases in secondary air pollutants are estimated to be 400 tpy of NOx, 200 tpy of CO, 700 tpy of SO2 and 20 tpy of PM.  We also estimated increases of greenhouse gas emissions (chiefly CO2) to be 800,000 tpy (existing kilns) and 200,000 tpy (new kilns). 
G.	What are the energy impacts?

The addition of alkaline scrubbers, ACI systems, and RTO added to comply with the proposed amendments will result in increased energy use due to the electrical requirements for the scrubber and ACI systems and increased fan pressure drops, and natural gas to fuel the RTO. We estimate the additional national electrical demand to be 730 million kWhr per year and the natural gas use to be 700,000 MMBtu per year for existing kilns. For new kilns, assuming of the 20 new kilns to start up in the 5 years following promulgation of the final standard that 20 will add alkaline scrubbers, 2 will add an RTO, and 14 will install ACI systems, the electrical demand is estimated to be 180 million kWhr per year and the natural gas use to be 175,000 MMBtu per year.
H.	What are the cost impacts?

Under the proposed amendments, existing kilns are expected to add one or more control devices to comply with the proposed emission limits. In addition, each kiln would be required to install CEMS to monitor mercury, THC and HCl while bag leak detector (BLD) would be required to monitor performance of all baghouses.
We performed two separate cost analyses for this proposed rule.  In the engineering cost analysis we estimated the cost of the proposed amendments based on the type of control device that was assumed to be necessary to comply with the proposed emission standards. Based on baseline emissions of mercury, THC, HCl and PM for each kiln and the removal efficiency necessary to comply with the proposed emission limit for each HAP, an appropriate control device was identified. In assigning control devices to each kiln where more than one control device would be capable of reducing emissions of a particular HAP below the limit, we assumed that the least costly control would be installed.  For example, if a kiln could use either a scrubber or ACI to comply with the proposed limit for mercury, it was assumed that ACI would be selected over a scrubber because an ACI system would be less costly.  ACI also is expected to achieve a higher removal efficiency than a scrubber for mercury. In some instances, a more expensive technology was considered appropriate because the selected control reduced emissions of multiple pollutants.  For example, even though ACI would be less costly than a scrubber for controlling mercury, if the kiln also had to reduce HCl emissions, we assumed that a scrubber would be applied to control HCl as well as mercury because ACI would not control HCl.  However, for many kilns, our analysis assumes that multiple controls will have to be added because more than one control will be needed to control all HAP.  For example, ACI may be considered necessary to meet the limits for THC and/or mercury.  For the same kiln, a scrubber would also be required to reduce HCl emissions.  In this case we would allocate the cost of the control to controlling HCl emissions, not to the cost of controlling mercury emissions.  In addition, once we assigned a particular control device in most cases we assumed mercury and THC emissions reductions would equal the control device efficiency, and not the minimum reduction necessary to meet the emissions limit.  We believe this assumption is warranted because it matches costs with actual emissions reductions.  In the case of PM and HCl, we assumed the controlled facility would emit at the average level necessary to meet the standard (i.e., we assumed for PM that the controlled facility would emit at 0.01 lb/ton clinker, the average emission level, not 0.085 lb/ton clinker, the actual emissions limit), because the proposed emissions levels are extremely low.    
In a separate analysis performed using the ISIS model, we input into ISIS the baseline and controlled emissions rates for each pollutant, along with the maximum percent reduction achievable for a particular control technology, and allowed ISIS to base the control required on optimizing total production costs.  In addition, the ISIS model accounts for normal kiln retirements that would occur even in the absence of any regulatory action (i.e., as new kiln come on-line, older less efficient and more costly to operate kilns are retired).  In the first cost analysis, total national annual costs assume that all kilns currently operating continue to operate while 20 new kilns come on-line.
Table 8 presents the resulting add-on controls each approach estimated was necessary to meet the proposed emissions limits.
Table 8.  Control Installation Comparison

LSW
ACI
LWS+ACI
RTO
MB
FF
WS+RTO
Engineering Analysis
5
36
111
0
10
5
12
ISIS Model
4
26
93
14
0
0
0

  In the engineering analysis we estimated the total capital cost of installing alkaline scrubbers and ACI systems for mercury control, including monitoring systems, would be $71 million with annualized cost of $27 million. The estimated capital cost of installing ACI systems and RTO/scrubbers to reduce THC emissions would be $355 million with annualized cost of $110 million. The capital cost of adding scrubbers for the control of HCl is estimated to be $766 million with annualized cost of $124 million. The capital cost of adding membrane bags to existing baghouse and the replacement of ESP's with baghouses would be $56 million with annualized cost of $17 million. The total capital cost for the proposed amendments would be an estimated $1.23 billion with an annualized cost of $275 million.
The estimated emission control capital cost per new 1.2 million tpy kiln is $16.6 million and the annualized costs are estimated at $1.25 million for mercury control, $1.0 million for THC control, $1.8 million for HCl control and $270,000 for PM control. National annualized cost by the end of the fifth year will be an estimated $86.4 million.
In the ISIS results, we are not able to separate costs by pollutant because the model does an overall optimization of the production and air pollution control costs. The total annual costs of the ISIS model are $167 million in 2013, and are anticipated to increase to $180 million in 2018.  These impacts assume that in 2013 7 new kilns are installed and net 10 kilns are retired. These retirements include two kilns that we have determined may close due to not being able to meet the mercury emission limits due to unusually high mercury contents in their proprietary quarries (i.e., the mercury content of the raw material at limestone quarries).
I.  What are the economic impacts?
	EPA employed both a partial-equilibrium economic model and the ISIS model to analyze the impact on the industry and the economy.  
	The Economic Impact Analysis model estimates the average national price for portland cement could be 4 percent higher with the NESHAP, or $3.30 per metric ton, while annual domestic production may fall by 8 percent, or 7 million tons per year. Because of higher domestic prices, imports are expected to rise by 2 million metric tons per year. 
	 As domestic production falls, cement industry revenues are projected to decline by 4 percent, or $340 million. Overall, net production costs also fall by $140 million with compliance cost increases ($240 million) offset by cost reductions associated with lower cement production. Operating profits fall by $200 million, or 16 percent. Other projected impacts include reduced demand for labor. Employment falls by approximately 8 percent, or 1,200 employees. EPA identified six domestic plants with negative operating profits and significant utilization changes that could temporarily idle until market demand conditions improve. The plants are small capacity plants with unit compliance costs close to $5 per ton and $50 million total change in operating profits. Since these plants account for approximately 2.5 percent of domestic capacity, a decision to permanently shut down these plants would reduce domestic supply and lead to additional projected market price increases. 
	The estimated domestic social cost of the proposed amendments is $684 million. There is an estimated $89 million surplus gain for other countries producing cement.  The social cost estimates are significantly higher than the engineering analysis estimates, which estimated annualized costs of $370 million. This is a direct consequence of EPA's assumptions about existing domestic plants' pricing behavior.  Under baseline conditions without regulation, the existing domestic cement plants are assumed to choose a production level that is less than the level produced under perfect competition. The imposition of additional regulatory costs tends to widen the gap between price and marginal cost in these markets and contributes to additional social costs. For more detail see the Regulatory Impact Analysis (RIA).
	Using the ISIS model, we estimate cement demand to drop 2.9 percent in 2013 or 3.9 million tons with an average annual drop in demand at 2.3 percent or 3.2 million tons per year during the  2013-2018 time period.  The drop in demand will affect the level of imports, and imports are likely to rise slightly over the policy horizon.  In 2013, imports rise 2.6 percent or 0.92 million tons with an annual average of 2.3 percent or 0.89 million tons per year throughout the 2013-2018.  ISIS estimates the average national price for portland cement in the 2013-2018 time period to be 0.2 percent higher with the NESHAP, or $0.20 per metric ton.  However, some markets could see an increase by up to 4.5 percent.  Total annualized control cost for the proposed NESHAP amendments is projected to be $167 million in 2013, and is expected to increase to $180 million in 2018, as additional new units come online to meet the projected increase in demand. 
	With respect to the baseline case in 2013, ISIS identified a net retirement of 5.2 million tons of capacity.  The retirements affect 10 kilns at 8 facilities.  As a result of the proposed NESHAP amendments, the cost to produce a ton of cement (production, imports, transportation and control technology) increases from $56.11 per ton at baseline to $57.83 per ton as a result of these proposed amendments ($1.72/ton), resulting in an increase of about 3 percent over the analysis period of 2013 to 2018.  With respect to baseline in 2013 ISIS projects the revenue of the cement industry to fall by 8 percent or about $615 million.  More information on this model can be found in the ISIS TSD and in a Technical Memo to the docket.
J.  What are the benefits?
We estimate the monetized benefits of this proposed NESHAP to be $4.4 billion to $11 billion (2005$, 3percent discount rate) in the year of full implementation (2013); using alternate relationships between PM2.5 and premature mortality supplied by experts, higher and lower benefits estimates are plausible, but most of the expert-based estimates fall between the two estimates we present above.  The benefits at a 7 percent discount rate are $4.0 billion to $9.7 billion (2005$).  We base the estimate of human health benefits derived from the PM2.5 and PM2.5 precursor emission reductions on the approach and methodology laid out in the TSD that accompanied the RIA for the revision to the National Ambient Air Quality Standard for Ground-level Ozone (NAAQS), March 2008 with several updates explained below.  We generated estimates that represent the total monetized human health benefits (the sum of premature mortality and morbidity) of reducing PM2.5 and PM2.5 precursor emissions.  A summary of the monetized benefits estimates at discount rates of 3 percent and 7 percent is in Table 7 of this preamble.  

Table 7.  Summary of the Monetized Benefits Estimates for the Proposed Portland Cement NESHAP
                                   Pollutant
                          Emission reductions (tons)
      Total monetized benefits (millions of 2005 dollars, 3% Discount)[1]
  Total monetized benefits (millions of 2005 dollars, 7 percent Discount)[1]
                                 Direct PM2.5 
                                     6,300
                               $1,200 to $2,800
                               $1,000 to $2,500
                               PM2.5 precursors
                                    140,000
                               $3,300 to $8,000
                               $3,000 to $7,200
                                 Grand total:
                               $4,400 to $11,000
                               $4,000 to $9,700
[1]All estimates are for the analysis year (full implementation, 2013), and are rounded to two significant figures so numbers may not sum across rows.  PM2.5 precursors reflect emission reductions of SOx.  All fine particles are assumed to have equivalent health effects, and the monetized benefits incorporate the conversion from precursor emissions to ambient fine particles.  These monetized benefits do not include HAP reductions, additional emission reductions that would occur if cement facilities temporarily idle or reduce capacity utilization as a result of this regulation, or the unquantifiable amount of reductions in condensable PM.
The specific estimates of benefits per ton of pollutant reductions included in this analysis are
       largely driven by the concentration response function for premature mortality.  Experts have advised EPA to consider a variety of assumptions, including estimates based both on empirical (epidemiological) studies and judgments elicited from scientific experts, to characterize the uncertainty in the relationship between PM2.5 concentrations and premature mortality.  For this proposed NESHAP we cite two key empirical studies, one based on the American Cancer Society cohort study  and the extended Six Cities cohort study.  Alternate models identified by experts describing the relationship between PM2.5 and premature mortality would yield higher and lower estimates, but most of the expert-based estimates fall between the two epidemiology-based estimates (Roman et al. 2008).  
      EPA has incorporated several updates to the benefit-per-ton estimates, including two technical updates and removing the assumption regarding thresholds in the health impact function.  Removing thresholds is supported by a wide body of peer-reviewed literature on the health effects of short and longer term PM exposures.
        Approximately 75 percent of the difference between the old methodology and the new methodology for this rule is due to removing thresholds with 25 percent due to the two technical updates, but this percentage would vary depending on the combination of emission reductions from different sources and PM2.5 precursor pollutants.  For more information on the updates to the benefit-per-ton estimates, please refer to the RIA for this proposed rule that is available in the docket.
      
      
      To generate the benefit-per-ton estimates, we used a model to convert emissions of direct PM2.5 and PM2.5 precursors into changes in PM2.5 air quality and another model to estimate the changes in human health based on that change in air quality.  Finally, the monetized health benefits were divided by the emission reductions to create the benefit-per-ton estimates.  Even though all fine particles are assumed to have equivalent health effects, the benefit-per-ton estimates vary between precursors because each ton of precursor reduced has a different propensity to form PM2.5.  For example, SOX has a lower benefit-per-ton estimate than direct PM2.5 because it does not form as much PM2.5, thus the exposure would be lower, and the monetized health benefits would be lower.  
 This analysis does not include the type of detailed uncertainty assessment found in the 2006 PM2.5 NAAQS RIA because we lack the necessary air quality input and monitoring data to run the benefits model.  However, the 2006 PM2.5 NAAQS benefits analysis provides an indication of the sensitivity of our results to the use of alternative concentration response functions, including those derived from the PM expert elicitation study.  
The annualized costs of this rulemaking are estimated at $694 million (2005$) in the year of full implementation, and the benefits are estimated at $4.4 billion to $11 billion (2005$, 3 percent discount rate) for that same year.  The benefits at a 7 percent discount rate are $4.0 billion to $9.7 billion (2005$).  Thus, net benefits of this rulemaking are estimated at $3.7 billion to $11 billion (2005$, 3 percent discount rate); using alternate relationships between PM2.5 and premature mortality supplied by experts, higher and lower benefits estimates are plausible, but most of the expert-based estimates fall between the two estimates we present above.  The net benefits at a 7 percent discount rate are $3.3 billion to $9.0 billion (2005$).  EPA believes that the benefits are likely to exceed the costs by a significant margin even when taking into account the uncertainties in the cost and benefit estimates.  
It should be noted that the benefits estimates provided above does not include benefits from improved visibility, coarse PM emission reductions, or other hazardous air pollutants such as mercury and hydrochloric acid, additional emission reductions that would occur if cement facilities temporarily idle or reduce capacity utilization as a result of this regulation, or the unquantifiable amount of reductions in condensable PM.  We do not have sufficient information or modeling available to provide such estimates for this rulemaking.  
For more information, please refer to the RIA for this proposed rule that is available in the docket.
VII.  Statutory and Executive Order Reviews
 A.  Executive Order 12866:  Regulatory Planning and Review
 	Under Executive Order 12866 (58 FR 51735, October 4, 1993), this action is a "significant regulatory action" because it may raise novel legal or policy issues.  
	Accordingly, EPA submitted this action to OMB for review under Executive Order 12866, and any changes made in response to OMB recommendations have been documented in the docket for this action.
 B.  Paperwork Reduction Act
The information collection requirements in this proposed rule have been submitted for approval to the 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 1801.07.
In most cases, new and existing kilns and in-line kiln/raw mills at major and area sources that are not already subject to emission limits for THC, mercury, and PM would become subject to the limits and associated compliance provisions in the current rule.  New compliance provisions for mercury would remove the current requirement for an initial performance test coupled with monitoring of the carbon injection rate.  Instead, plants would monitor mercury emissions by determining the monthly and rolling 12-month mercury throughput using a material balance procedure.  The procedure would require daily sampling of process inputs (feed, baghouse dust, fuels) and analysis of the mercury concentration in a monthly composite sample.  Records of all calculations and data would be required.  New compliance procedures would also apply to area sources subject to a PM limit in a format of lbs/ton of clinker.  The owner or operator would be required to install and operate a weight measurement system and keep daily records of clinker production instead of the current requirement to install and operate a PM CEMS.  The owner or operator would be required to conduct an initial PM performance test and repeat performance tests every 5 years.  Cement plants also would be subject to new limits for HCl and associated compliance provisions which include compliance tests using EPA Method 321 and continuous monitoring for HCl for facilities that do not use a wet scrubber for HCl control.  These requirements are based on the recordkeeping and reporting requirements in the NESHAP General Provisions (40 CFR part 63, subpart A) which are mandatory for all operators subject to national emission standards.  These recordkeeping and reporting requirements are specifically authorized by section 114 of the CAA (42 U.S.C. 7414).  All information submitted to EPA pursuant to the recordkeeping and reporting requirements for which a claim of confidentiality is made is safeguarded according to EPA policies set forth in 40 CFR part 2, subpart B.
	The annual burden for this information collection averaged over the first 3 years of this ICR is estimated to total 44,656 labor-hours per year at a cost of $4.1 million per year.  The average annualized capital costs are estimated at $53.7 million per year and average operation and maintenance costs are estimated at $174,000 per year.  Burden is defined at 5 CFR 1320.3(b).
	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 are listed in 40 CFR part 9.
 To comment on the Agency's need for this information, the accuracy of the provided burden estimates, and any suggested methods for minimizing respondent burden, EPA has established a public docket for this proposed rule, which includes this ICR, under Docket ID number EPA-HQ-OAR-2002-0051.  Submit any comments related to the ICR for this proposed rule to EPA and OMB.  See ADDRESSES section at the beginning of this document for where to submit comments to EPA.  Send comments to OMB at the Office of Information and Regulatory Affairs, Office of Management and Budget, 725 17[th] Street, NW, Washington, DC 20503, Attention:  Desk Office for EPA.  Since OMB is required to make a decision concerning the ICR between 30 and 60 days after [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER], a comment to OMB is best assured of having its full effect if OMB receives it by [INSERT DATE 30 DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER].  The final rule will respond to any OMB or public comments on the information collection requirements contained in this proposal.
 C.  Regulatory Flexibility Act
 	The Regulatory Flexibility Act 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 this rule on small entities, small entity is defined as:  (1) a small business whose parent company has no more than 750 employees (as defined by Small Business Administration (SBA) size standards for the portland cement industry, NAICS 327310); (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 impact of this proposed rule on small entities, I certify that this action will not have a significant economic impact on a substantial number of small entities.  We estimate that up to 4 of the 44 existing portland cement plants are small entities.  One of the entities burns hazardous waste in its kiln and is not impacted by this proposed rule.  
       EPA performed a screening analysis for impacts on the three affected small entities by comparing compliance costs to entity revenues. EPA's analysis found that the ratio of compliance cost to company revenue for two small entities (including a tribal government) would have an annualized cost of between 1 percent and 3 percent of sales. One small business would have an annualized cost of 4.8 percent of sales.  In addition to the screening analysis, EPA also examined small entity effects after accounting for market adjustments. Under this assumption, the entities recover some of the regulatory program costs as the market price adjusts in response to higher cement production costs. Even after accounting for these adjustments, small entity operating profits fall by $4 million, or 9 percent. All three affected facilities are projected to continue to operate under with-regulation conditions. 
	EPA also evaluated small business impacts using the ISIS model.  There are a total of 7 kilns identified to be associated with small business facilities affected by this proposal. ISIS identified one of these kilns to retire in 2013 as a result of the proposed NESHAP.  A second kiln reduces its utilization by 56 percent in 2013 but recovers later in the 2013 to 2018 time frame as the demand increases.  All the remaining small business kilns operate at full capacity throughout the 2013 to 2018 time frame.    
       Although this proposed rule will not impact a substantial number of small entities, EPA nonetheless has tried to reduce the impact of this proposed rule on small entities by setting the proposed emissions limits at the MACT floor, the least stringent level allowed by law.  In the case where there are overlapping standards between this NESHAP and the Portland Cement NSPS, we have exempted sources from the least stringent requirement thereby eliminating the overlapping monitoring, testing and reporting requirements by proposing that the source comply with only the more stringent of the standards.  We continue to be interested in the potential impacts of this proposed rule on small entities and welcome comments on issues related to such impacts.
 D.  Unfunded Mandates Reform Act
 	Title II of the Unfunded Mandates Reform Act (UMRA), 2 U.S.C 1531-1538, requires Federal agencies, unless otherwise prohibited by law, to assess the effects of their regulatory actions on State, local, and tribal governments and the private sector.  Federal agencies must also develop a plan to provide notice to small governments that might be significantly or uniquely affected by any regulatory requirements. The plan must enable officials of affected small governments to have meaningful and timely input in the development of EPA regulatory proposals with significant Federal intergovernmental mandates and must inform, educate, and advise small governments on compliance with the regulatory requirements.
 	This rule contains 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 one year.  Accordingly, EPA has prepared under section 202 of the UMRA a written statement which is summarized below. 
 	Consistent with the intergovernmental consultation provisions of section 204 of the UMRA EPA has already initiated consultations with the governmental entities affected by this rule. In developing this rule, EPA consulted with small governments under a plan developed pursuant to section 203 of UMRA concerning the regulatory requirements in the rule that might significantly or uniquely affect small governments. EPA has determined that this proposed action contains regulatory requirements that might significantly or uniquely affect small governments because one of the facilities affected by the proposed rule is tribally owned. EPA consulted with tribal officials early in the process of developing this regulation to permit them to have meaningful and timely input into its development.  EPA directly contacted the facility in question to insure they were apprised of this rulemaking and potential implications.  This facility indicated they were aware of the rulemaking and were participating in meeting with the industry trade association concerning this rulemaking.  The facility did not indicate any specific concern, and we are assuming that they have the same concerns as those expresses by the other non-tribally owned facilities during the development of this proposed rule.    	
 	Consistent with section 205, EPA has identified and considered a reasonable number of regulatory alternatives. EPA carefully examined regulatory alternatives, and selected the lowest cost/least burdensome alternative that EPA deems adequate to address Congressional concerns and to effectively reduce emissions of mercury, THC and PM. EPA has considered the costs and benefits of the proposed rule, and has concluded that the costs will fall mainly on the private sector (approximately $273 million). EPA estimates that an additional facility owned by a tribal government will incur approximately $2.1 million in costs per year. Furthermore, we think it is unlikely that State, local and Tribal governments would begin operating large industrial facilities, similar to those affected by this rulemaking operated by the private sector.
 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."
This proposed rule does not have federalism implications.  It 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.  None of the affected facilities are owned or operated by State governments.  Thus, Executive Order 13132 does not apply to this proposed rule.
In the spirit of Executive Order 13132, and consistent with EPA policy to promote communications between EPA and State and local governments, EPA specifically solicits comment on this proposed action from State and local officials.
 F.  Executive Order 13175:  Consultation and Coordination with Indian Tribal Governments
 	Subject to the Executive Order 13175 (65 FR 67249, November 9, 2000) EPA may not issue a regulation that has tribal implications, that imposes substantial direct compliance costs, and that is not required by statute, unless the Federal government provides the funds necessary to pay the direct compliance costs incurred by tribal governments, or EPA consults with tribal officials early in the process of developing the proposed regulation and develops a tribal summary impact statement.
 	EPA has concluded that this action will have tribal implications, because it will impose substantial direct compliance costs on tribal governments, and the Federal government will not provide the funds necessary to pay those costs.  One of the facilities affected by this proposed rule is tribally owned.  We estimate this facility will incur direct compliance costs that are between 1 to 3 percent of sales.  Accordingly, EPA provides the following tribal summary impact statement as required by section 5(b).  
 	EPA consulted with tribal officials early in the process of developing this regulation to permit them to have meaningful and timely input into its development.  EPA directly contacted the facility in question to insure they were apprised of this rulemaking and potential implications.  This facility indicated they were aware of the rulemaking and were participating in meeting with the industry trade association concerning this rulemaking.  The facility did not indicate any specific concern, and we are assuming that they have the same concerns as those expresses by the other non-tribally owned facilities during the development of this proposed rule.  
 	EPA specifically solicits additional comment on this proposed action from tribal officials.
 G.  Executive Order 13045:  Protection of Children from Environmental Health Risks and Safety Risks
EPA interprets Executive Order 13045 as applying to those regulatory actions that concern health or safety risks, such that the analysis required under section 5-501 of the Order has the potential to influence the regulation.  This proposed action is not subject to Executive Order 13045 because it is based solely on technology performance.    
 H.  Executive Order 13211:  Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use
      This proposed 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.  Further, we have concluded that this proposed rule is not likely to have any adverse energy effects.  This proposal will result in the addition of control equipment and monitoring systems for existing and new sources.  We estimate the additional electrical demand to be 784 million kWhr per year and the natural gas use to be 672 million cubic feet for existing sources. At the end of the fifth year following promulgation, electrical demand from new sources will be 180 million kWhr per year and natural gas use will be 171 million cubic feet.
      I.  National Technology Transfer and Advancement Act
 	Section 12(d) of the National Technology Transfer and Advancement Act of 1995 ("NTTAA"), Public Law No. 104-113 (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.  VCS are technical standards (e.g., materials specifications, test methods, sampling procedures, and business practices) that are developed or adopted by VCS bodies.  NTTAA directs EPA to provide Congress, through OMB, explanations when the Agency decides not to use available and applicable VCS.
 	These proposed amendments involve technical standards.  The EPA proposes to cite Performance Specifications 8A of 40 CFR part 60appendix B for THC, 12A and 12B of 40 CFR part 60 appendix B for mercury and 15 of 40 CFR part 60 appendix B for HCl continuous monitor operation and maintenance.  In addition EPA proposes to use the following test methods to determine compliance:  EPA Method 5 of 40 CFR Appendix B for PM; EPA Method 321 of 40 CFR Appendix B for HCl; and EPA Method 320 of 40 CFR Appendix B for organic HAP.
 		Consistent with the NTTAA, EPA conducted searches through the Enhanced NSSN Database managed by the American National Standards Institute (ANSI).  We also contacted VCS organizations, and accessed and searched their databases.  	
 	
 	
 	
 	
 	
 	
 J.  Executive Order 12898:  Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations
Executive Order 12898 (59 FR 7629 (Feb. 16, 1994)) establishes Federal executive policy on environmental justice.  Its main provision directs Federal agencies, to the greatest extent practicable and permitted by law, to make environmental justice part of their mission by identifying and addressing, as appropriate, disproportionately high and adverse human health or environmental effects of their programs, policies, and activities on minority populations and low-income populations in the United States.  EPA has determined that these proposed amendments will not have disproportionately high and adverse human health or environmental effects on minority or low-income
populations because they would increase the level of environmental protection for all affected populations without having any disproportionately high and adverse human health or environmental effects on any population, including any minority or low-income population.  These proposed standards would reduce emissions of mercury, THC, HCl, and PM from portland cement plants located at major and area sources, decreasing the amount of such emissions to which all affected populations are exposed. 
List of Subjects in 40 CFR Part 63
	Environmental protection, Air pollution control, Hazardous substances, Incorporation by reference, and Reporting and recordkeeping requirements.
 
 		
 Dated:
 
 
 				
 Lisa P. Jackson,
 Administrator.
 

	For the reasons stated in the preamble, title 40, chapter I, of the Code of Federal Regulations is proposed to be 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.	Section 63.1340 is amended as follows:
	a.  By revising paragraph (a);
	b.  By revising paragraphs (b)(1) through (b)(8); and
	c.  By revising paragraph (c).
 §63.1340  Applicability and designation of affected sources.
	(a)  The provisions of this subpart apply to each new and existing portland cement plant which is a major source or an area source as defined in §63.2.
	(b)  * * * 
	(1)  Each kiln and each in-line kiln/raw mill, including alkali bypasses, except for kilns and in-line kiln/raw mills that burn hazardous waste and are subject to and regulated under subpart EEE of this part;
	(2)  Each clinker cooler at any portland cement plant;
	(3)  Each raw mill at any portland cement plant;
	(4)  Each finish mill at any portland cement plant;
	(5)  Each raw material dryer at any portland cement plant;
	(6) Each raw material, clinker, or finished product storage bin at any portland cement plant;
	(7)  Each conveying system transfer point including those associated with coal preparation used to convey coal from the mill to the kiln at any portland cement plant; and
	(8)  Each bagging and bulk loading and unloading system at any portland cement plant.
	(c)  Crushers are not covered by this subpart regardless of their location.
*   *   *   *   *
      3.  Section 63.1341 is amended by adding definitions for "Clinker," "Crusher," "New Source" and "Total organic HAP" in alphabetic order to read as follows:
§63.1341  Definitions.
*  *  *  *  *
	Clinker means the product of the process in which limestone and other materials are heated in the kiln and is then ground with gypsum and other materials to form cement.
*  *  *  *  *
      Crusher means a machine designed to reduce large rocks from the quarry into materials approximately the size of gravel.  
* * * * * *
	New Source means any source that commences construction after December 2, 2005 for purposes of determining the applicability of the kiln in-line raw mill/kiln, clinker cooler and raw material dryer emissions limits for mercury, THC, and HCl.  New source means any source that commences construction after [INSERT THE DATE OF PUBLICATION OF THIS PROPOSED RULE IN THE FEDERAL REGISTER] for purposes of determining the applicability of the kiln in-line raw mill/kiln AND clinker cooler emissions limits for PM.
*  *  *  *  *
	Total organic HAP means, for the purposes of this subpart, the sum of the concentrations of compounds of formaldehyde, benzene, toluene, styrene, m-xylene, p-xylene, o-xylene, acetaldehyde, and naphthalene as measured by EPA Test Method 25 or 25A.  Only the measured concentration of the listed analytes that are present at concentrations exceeding one-half the quantitation limit of the analytical method are to be used in the sum.  If any of the analytes are not detected or are detected at concentrations less than one-half the quantitation limit of the analytical method, the concentration of those analytes will be assumed to be zero for the purposes of calculating the total organic HAP for this subpart.
*  *  *  *  *
      4.  Section 63.1343 is amended:
      a.  By revising paragraph (a);
      b.  By revising paragraph (b) introductory text,
      c.  By revising paragraph (b)(1); 
      d.  By adding paragraphs (b)(4) through (b)(6);
      e.  By revising paragraph (c) introductory text;
      f.  By revising paragraphs (c)(1), (c)(4) and (c)(5); and
      g.  By adding paragraph (c)(6),
      h.  By removing paragraphs (d) and (e) 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 dioxin furan (D/F) and THC emission limits are on a dry basis, corrected to 7 percent oxygen. All total hydrocarbon (THC) emission limits are measured as propane. 
	(b)  Existing kilns located at major or area sources. No owner or operator of an existing kiln or an existing in-line kiln/raw mill located at a facility that is 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 0.085 pounds per ton of clinker.  When there is an alkali bypass associated with a kiln or in-line kiln/raw mill, the combined PM emissions from the kiln or in-line kiln/raw mill and the alkali bypass stack are subject to this emission limit.  Kiln, or in-line kiln/raw mills that combine the clinker cooler exhaust with the kiln exhaust for energy efficiency purposes and send the combined exhaust to the PM control device as a single stream may meet and alternative PM emissions limit.  This limit is calculated using the following equation:  
	PM alt  =  0.0067 x 1.65 x (Qk + Qc)/7000  		(Eq. 1)
                        Where: 0.0067 is the PM exhaust concentration equivalent to 0.085 lb per ton clinker where clinker cooler and kiln exhaust gas are not combined. 
            Qk is the exhaust flow of the kiln (dscf/ton raw 			  feed)
		 Qc is the exhaust flow of the clinker cooler (dscf/ton 		  	raw feed)

*  *  *  *  *
      (4)  Contain THC in excess of 7 ppmv or total organic HAP in excess of 2 ppmv from the main exhaust of the kiln or in-line kiln/raw mill.
      (5)  Contain mercury (Hg) in excess of 43 lb per million tons of clinker. When there is an alkali bypass associated with a kiln or in-line kiln/raw mill, the combined Hg emissions from the kiln or in-line kiln/raw mill and the alkali bypass are subject to this emission limit.  
      (6)  Contain hydrogen chloride (HCl) in excess of 2 ppmv from the main exhaust of the kiln or in-line kiln/raw mill if the kiln or in-line kiln/raw mill is located at a major source of HAP emissions.	
      (c)  New or reconstructed kilns located at major or area sources.  No owner or operator of a new or reconstructed kiln or new or reconstructed inline kiln/raw mill located at a facility subject to the provisions of this subpart shall cause to be discharged into the atmosphere from these affected sources any gases which:
	(1)  Contain PM in excess of 0.080 pounds per ton of clinker.  When there is an alkali bypass associated with a kiln or in-line kiln/raw mill, the combined PM emissions from the kiln or in-line kiln/raw mill and the alkali bypass stack are subject to this emission limit.  Kiln, or in-line kiln/raw mills that combine the clinker cooler exhaust with the kiln exhaust for energy efficiency purposes and send the combined exhaust to the PM control device as a single stream may meet an alternative PM emissions limit.  This limit is calculated using the following equation:  
	PM alt  =  0.0063 x 1.65 x (Qk + Qc)/7000  		(Eq. 2)
                        Where: 0.0063 is the PM exhaust concentration equivalent to 0.080 lb per ton clinker where clinker cooler and kiln exhaust gas are not combined. 
            Qk is the exhaust flow of the kiln (dscf/ton raw 			  feed)
		 Qc is the exhaust flow of the clinker cooler (dscf/ton 		  	raw feed)

*  *  *  *  *
	(4)  Contain THC in excess of 6 ppmv, or total organic HAP in excess of 1 ppmv, from the main exhaust of the kiln, or main exhaust of the in-line kiln/raw mill.  
      (5)  Contain Hg from the main exhaust of the kiln, or main exhaust of the in-line kiln/raw mill, in excess of 14 lb/million tons of clinker. When there is an alkali bypass associated with a kiln, or in-line kiln/raw mill, the combined Hg emissions from the kiln or in-line kiln/raw mill and the alkali bypass are subject to this emission limit. 
	 (6)  Contain HCl in excess of 0.1 ppmv from the main exhaust of the kiln, or main exhaust of the in-line kiln/raw mill if the kiln or in-line kiln/raw mill is located at a major source of HAP emissions.		
	5.  Section 63.1344 is amended:
	a.  By revising paragraph (c) introductory text, 
	b.  By revising paragraphs (d) and (e); and
      b.  By removing paragraphs (f),(g) (h) and (i) to read as follows:
§63.1344  Operating limits for kilns and in-line kiln/raw mills.
*   *   *   *   *
	(c)  The owner or operator of an affected source subject to a 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.
*  *  *  *  *
	(d)  Except as provided in paragraph (e) of this section, the owner or operator of an affected source subject to a 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 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.
	6.  Section 63.1345 is amended by revising paragraph (a) introductory text and paragraph (a)(1) to read as follows:
§63.1345  Standards for clinker coolers.
	(a)  No owner or operator of a new or existing clinker cooler at a facility which is a major source or an area source subject to the provision of this subpart shall cause to be discharged into the atmosphere from the clinker cooler any gases which:
	(1)  Contain PM in excess of 0.085 lb per ton of clinker for existing sources or 0.080 lb per ton of clinker for new sources.
*   *   *   *   *
	7.  Section 63.1346 is revised to read as follows:  
§63.1346  Standards for raw material dryers.
      (a) Raw material dryers that are located at facilities that are major sources can not discharge to the atmosphere any gases which:
      (1)  Exhibit opacity greater then 10 percent; or
      (2)  Contain THC in excess of 7 ppmv (existing sources) or 6 ppmv (new sources), on a dry basis as propane corrected to 7 percent oxygen.
      (b)  Raw Material dryers located at a facility that is an area source must not discharge to the atmosphere any gases which contain THC in excess of 7 ppmv (existing sources) or 6 ppmv (new sources), on a dry basis as propane corrected to 7 percent oxygen. 
      8.  Section 63.1349 is amended:
	a.  By revising paragraph (b) introductory text;
	b.  By revising paragraphs (b)(1)introductory text, (b)(1)(ii), (iii), (iv) and (vii); 
	c.  By revising paragraphs (b)(4) and (b)(5);  
	d.  By adding paragraph (b)(6);
	e.  By revising paragraph (c);
	f.  By adding paragraph (f); and 
	g.  By adding paragraph (g) to read as follows:
§63.1349  Performance testing requirements. 
*  *  *  *  *
	(b)  Performance tests to demonstrate initial compliance with this subpart shall be conducted as specified in paragraphs (b)(1) through (b)(7) of this section. 
	(1)  The owner or operator of a kiln subject to limitations on PM emissions that is not equipped with a PM CEMS shall demonstrate initial compliance by conducting a performance test as specified in paragraphs (b)(1)(i) through (b)(1)(iv) of this section.  The owner or operator of an in-line kiln/raw mill subject to limitations on PM emissions that is not equipped with a PM CEMS shall demonstrate initial compliance by conducting separate performance tests as specified in paragraphs (b)(1)(i) through (b)(1)(iv) of this section 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.  The owner or operator of a clinker cooler subject to limitations on PM emissions shall demonstrate initial compliance by conducting a performance test as specified in paragraphs (b)(1)(i) through (b)(1)(iii) of this section.  The owner or operator shall determine the opacity of PM emissions exhibited during the period of the Method 5 (40 CFR part 60, appendix A-3) performance tests required by paragraph (b)(1)(i) of this section as required in paragraphs (b)(1)(v) through (vi) of this section.  The owner or operator of a kiln or inline kiln/raw mill subject to limitations on PM emissions that is equipped with a PM CEMS shall demonstrate initial compliance by conducting a performance test as specified in paragraph (b)(1)(vii) of this section.
*  *  *  *  *
	(ii)  The owner or operator must install, calibrate, maintain and operate a permanent weigh scale system, or use another method approved by the Administrator, to measure and record weight rates in tons-mass per hour of the amount of clinker produced.  The system of measuring hourly clinker production must be maintained within +-5 percent accuracy. The use of a system that directly measures kiln feed rate and uses a conversion factor to determine the clinker production rate is an acceptable method.
            (iii)  The emission rate, E, of PM (1b/ton of clinker) shall be computed for each run using equation 1 of this section:
      
                                  			(Eq. 3)
Where:
E = emission rate of particulate matter, kg/metric ton (lb/ton) of clinker production;
Cs = concentration of particulate matter, g/dscm (gr/dscf);
Qsd = volumetric flow rate of effluent gas, dscm/hr (dscf/hr);
P = total kiln clinker production rate, metric ton/hr (ton/hr); and
K = conversion factor, 1000 g/kg (7000 gr/lb).
	
      (iv)  Where there is an alkali bypass associated with a kiln or in-line kiln/raw mill, the main exhaust and alkali bypass of the kiln or in-line kiln/raw mill shall be tested simultaneously and the combined emission rate of particulate matter from the kiln or in-line raw mill and alkali bypass shall be computed for each run using equation 2 of this section:
                                  			(Eq. 4)

Where:
Ec = combined emission rate of particulate matter from the kiln or in-line kiln/raw mill and bypass stack, kg/metric ton (lb/ton) of kiln clinker production;
Csk = concentration of particulate matter in the kiln or in-line kiln/raw mill effluent gas, g/dscm (gr/dscf);
Qsdk = volumetric flow rate of kiln or in-line kiln/raw mill effluent gas, dscm/hr (dscf/hr);
Csb = concentration of particulate matter in the alkali bypass gas, g/dscm (gr/dscf);
Qsdb = volumetric flow rate of alkali bypass effluent gas, dscm/hr (dscf/hr);
P = total kiln clinker production rate, metric ton/hr (ton/hr); and
K = conversion factor, 1000 g/kg (7000 gr/lb).
conversion factor, 1000 g/kg (7000 gr/lb).
*  *  *  *  *
(vii)

        The owner or operator of a kiln or in-line kiln/raw mill subject to limitations on emissions of PM that is equipped with a PM CEMS shall demonstrate initial compliance by operating the CEMS in accordance with Performance Specification 11 (40 CFR part 60, appendix B).  The duration of the test shall be 3 hours.  The owner or operator shall calculate the PM emission rate in kg/metric ton (lb/ton) of clinker using Equation 1 or 2 of this section.  The owner or operator of an in-line kiln/raw mill shall conduct 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.  The owner or operator shall continuously measure kiln feed rate, volumetric flow rate, and clinker production during the period of the test.  

	

	
*  *  *  *  *
      (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 (40 CFR part 60, appendix B).  The duration of the performance test shall be 24 hours.  The owner or operator shall calculate the daily average THC concentration (as calculated from the one-minute averages) during the performance test. 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) As an alternative to complying with the THC limit, the owner or operator may comply with the limits for total organic HAP, as defined in §63.1341, by following the procedures in (b)(4)(ii) through (b)(4)(vi) of this section.
	(iii) The owner or operator of a kiln complying with the alternative emissions limits for total organic HAP in §63.1343 shall demonstrate initial compliance by conducting a performance test as specified in paragraphs (b)(4)(ii) through (b)(4)(vi) of this section.  The owner or operator of an in-line kiln/raw mill complying with the emissions limits for total organic HAP in §63.1343 shall demonstrate initial compliance by conducting separate performance tests as specified in paragraphs (b)(4)(ii) through (b)(4)(vi) of this section 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. 
      (iv)  Method 320 of appendix A to this part alone or in combination with method 18 of appendix A to part 60 of this chapter shall be used to determine emissions of total organic HAP. Each performance test shall consist of three separate runs under the conditions that exist when the affected source is operating at the representative performance conditions in accordance with §63.7(e). Each run shall be conducted for at least 1 hour. The average of the three runs shall be used to determine initial compliance.
      (v) At the same time that the owner or operator is determining compliance with the emissions limits for total organic HAP, the owner or operator shall also determine THC emissions 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 test shall be three hours, and the average THC concentration (as calculated from the one-minute averages) during the three-hour test shall be calculated. The THC concentration measured during the initial performance test for total organic HAP will be used to monitor compliance subsequent to the initial performance test.
      (vi)  Emissions tests to determine compliance with total inorganic HAP limits shall be repeated annually, beginning one year from the date of the initial performance tests.
      (5)  The owner or operator of a kiln or in-line kiln/raw mill subject to an emission limitation for mercury in §63.1343 shall demonstrate initial compliance with the mercury limit by complying with the requirements of (b)(5)(i) through (b)(5)(vi) of this section. 
      (i)  Operate a continuous emission monitor in accordance with Performance Specification 12A (40 CFR part 60, appendix B).  The duration of the performance test shall be a calendar month.  For each calendar month in which the kiln or in-line kiln/raw mill operates, hourly Hg concentration data, stack gas volumetric flow rate data shall be obtained. 
      The owner or operator of an in-line kiln/raw mill shall demonstrate initial compliance by operating a continuous emission monitor 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)  Owners or operators using a mercury CEMS must install, operate, calibrate, and maintain an instrument for continuously measuring and recording the exhaust gas flow rate to the atmosphere according to the requirements in §60.63(m) of this chapter.
      (iii)  The owner or operator shall determine compliance with the Hg limitations by dividing the average Hg concentration by the clinker production rate during the same calendar month using the Equation 3 of this section:
      
                                  			(Eq. 5)

Where:
E = emission rate of mercury, kg/metric ton (lb/million tons) of clinker production;
Cs = concentration of mercury, g/dscm (g/dscf);
Qsd = volumetric flow rate of effluent gas, dscm/hr (dscf/hr);
P = total kiln clinker production rate, metric ton/hr (million ton/hr); and
K = conversion factor, 1000 g/kg (454 g/lb).
 
      (6)  The owner or operator of an affected source subject to limitations on emissions of HCl shall demonstrate initial compliance with the HCl limit by one of the following methods:
       (i)  If your source is equipped with a wet scrubber such as a spray tower, packed bed, or tray tower, use Method 321 of appendix A to this part. A repeat test must be performed every 5 years to demonstrate continued compliance.
       (ii)  If your source is not controlled by a wet scrubber, you must operate a continuous emission monitor in accordance with Performance Specification 15 of appendix B of part 60.  The duration of the performance test shall be 24 hours.  The owner or operator shall calculate the daily average HCl concentration (as calculated from the one-minute averages) during the performance test. 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.
       (c)  Except as provided in paragraph (e) of this section, performance tests are required for existing kilns or in-line kiln/raw mills that are subject to a PM, THC, HCl or mercury emissions limit and must be repeated every 5 years except for pollutants where that specific pollutant is monitored using a CEMS.
*  *  *  *  *  
	(f) The owner or operator of an affected facility shall submit the information specified in paragraphs (c)(1) through (c)(4) of this section no later than 60 days following the initial performance test.  All reports shall be signed by the facilities manager.
	(1)  The initial performance test data as recorded under §60.56c(b)(1) through (b)(14), as applicable. 
	(2)  The values for the site-specific operating parameters established pursuant to §60.56c(d), (h), or (j), as applicable, and a description, including sample calculations, of how the operating parameters were established during the initial performance test.
	(3)  For each affected facility as defined in §60.50c(a)(3).
	(4)  That uses a bag leak detection system, analysis and supporting documentation demonstrating conformance with EPA guidance and specifications for bag leak detection systems in §60.57c(h).
	(g)  For affected facilities, as defined in §60.50c(a)(3) and (4), that choose to submit an electronic copy of stack test reports to EPA's WebFIRE data base, as of December 31, 2011, the owner or operator of an affected facility shall enter the test data into EPA's data base using the Electronic Reporting Tool located at http://www.epa.gov/ttn/chief/ert/ert_tool.html.
	9.  Section 63.1350 is amended:
	a.  By revising paragraph (g) introductory text;
	b.  By revising paragraph 
	
	
	
	(h) introductory text;
	c.  By revising paragraph (h)(2) through (h)(4);
	d.  By revising paragraph (k);
	b.  By revising paragraphs (m) introductory text;
	e.  By revising paragraph (n),(o) and (p); and
      c.  By adding new paragraph (q) and (r) 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 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 emissions standard.
*  *  *  *  *
	(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:
*  *  *  *  *
      (2)  For existing facilities complying with the THC emissions limits of §63.1343, the 30 day average THC concentration in any gas discharged from the main exhaust of a kiln, or in-line kiln/raw mill, must not exceed their THC emissions limit, reported as propane, corrected to seven percent oxygen.
      (3)  For new or reconstructed facilities complying with the THC emission limits of §63.1343, the 30 day average THC concentration in any gas discharged from the main exhaust of a kiln or in-line kiln/raw mill must not exceed their THC emission limit, reported as propane, corrected to seven percent oxygen.
      (4)  For new or reconstructed facilities complying with the THC emission limits of §63.1346, any daily average THC concentration in any gas discharged from a raw material dryer must not exceed their THC emission limit, reported as propane, corrected to seven percent oxygen.  
*  *  *  *  *
      (k)  The owner or operator of an affected source subject to a particulate matter standard under §63.1343 using a fabric filter for PM control must install, operate, and maintain a bag leak detection system according to paragraphs (k)(1) through (k)(3) of this section. 
      (1)  Each bag leak detection system must meet the specifications and requirements in paragraphs (k)(1)(i) through (k)(1)(viii) of this section. 
      (i)  The bag leak detection system must be certified by the manufacturer to be capable of detecting PM emissions at concentrations of 1 milligram per dry standard cubic meter (0.00044 grains per actual cubic foot) or less.
      (ii)  The bag leak detection system sensor must provide output of relative PM loadings.  The owner or operator shall continuously record the output from the bag leak detection system using electronic or other means (e.g., using a strip chart recorder or a data logger).
      (iii)  The bag leak detection system must be equipped with an alarm system that will sound when the system detects an increase in relative particulate loading over the alarm set point established according to paragraph (k)(1)(iv) of this section, and the alarm must be located such that it can be heard by the appropriate plant personnel.
      (iv)  In the initial adjustment of the bag leak detection system, you must establish, at a minimum, the baseline output by adjusting the sensitivity (range) and the averaging period of the device, the alarm set points, and the alarm delay time.
      (v)  Following initial adjustment, you shall not adjust the averaging period, alarm set point, or alarm delay time without approval from the Administrator or delegated authority except as provided in paragraph (k)(1)(vi) of this section.
      (vi)  Once per quarter, you may adjust the sensitivity of the bag leak detection system to account for seasonal effects, including temperature and humidity, according to the procedures identified in the site-specific monitoring plan required by paragraph (k)(2) of this section.
      (vii)  You must install the bag leak detection sensor downstream of the fabric filter.
      (viii)  Where multiple detectors are required, the system's instrumentation and alarm may be shared among detectors.
      (2)  You must develop and submit to the Administrator or delegated authority for approval a site-specific monitoring plan for each bag leak detection system.  You must operate and maintain the bag leak detection system according to the site-specific monitoring plan at all times.  Each monitoring plan must describe the items in paragraphs (k)(2)(i) through (k)(2)(vi) of this section. At a minimum you must retain records related to the site-specific monitoring plan and information discussed in paragraphs (k)(2)(i) through (k)(2)(vi) of this section for a period of 2 years on-site and 3 years off-site;
      (i)  Installation of the bag leak detection system;
      (ii)  Initial and periodic adjustment of the bag leak detection system, including how the alarm set-point will be established;
      (iii)  Operation of the bag leak detection system, including quality assurance procedures;
      (iv)  How the bag leak detection system will be maintained, including a routine maintenance schedule and spare parts inventory list;
      (v)  How the bag leak detection system output will be recorded and stored; and
      (vi)  Corrective action procedures as specified in paragraph (k)(3) of this section.  In approving the site-specific monitoring plan, the Administrator or delegated authority may allow owners and operators more than 3 hours to alleviate a specific condition that causes an alarm if the owner or operator identifies in the monitoring plan this specific condition as one that could lead to an alarm, adequately explains why it is not feasible to alleviate this condition within 3 hours of the time the alarm occurs, and demonstrates that the requested time will ensure alleviation of this condition as expeditiously as practicable.
      (3)  For each bag leak detection system, you must initiate procedures to determine the cause of every alarm within 1 hour of the alarm.  Except as provided in paragraph (k)(2)(vi) of this section, you must alleviate the cause of the alarm within 3 hours of the alarm by taking whatever corrective action(s) are necessary.  Corrective actions may include, but are not limited to the following:
      (i)  Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that may cause an increase in PM emissions;
      (ii)  Sealing off defective bags or filter media;
      (iii)  Replacing defective bags or filter media or otherwise repairing the control device;
      (iv)  Sealing off a defective fabric filter compartment;
      (v)  Cleaning the bag leak detection system probe or otherwise repairing the bag leak detection system; or
      (vi)  Shutting down the process producing the PM emissions.
      (4)  The owner or operator of a kiln or clinker cooler using a PM continuous emission monitoring system (CEMS) to demonstrate compliance with the particulate matter emission limit in §63.1343 must install, certify, operate, and maintain the CEMS as specified in paragraphs (p)(1) through (p)(3) of this section.
*  *  *  *  *
	(m)  The requirements under paragraph (e) of this section to conduct daily Method 22 testing shall not apply to any specific raw mill or finish mill equipped with a continuous opacity monitor system (COMS) or bag leak detection system (BLDS). If the owner or operator chooses to install a COM in lieu of conducting the daily visual emissions testing required under paragraph (e) of this section, then the COM must be installed at the outlet of the PM control device of the raw mill or finish mill, and the COM must be installed, maintained, calibrated, and operated as required by the general provisions in subpart A of this part and according to PS-1 of appendix B to part 60 of this chapter. The 6-miunute average opacity for any 6-minute block period must not exceed 10 percent. If the owner or operator chooses to install a BLDS in lieu of conducting the daily visual emissions testing required under paragraph (e) of this section, the requirements in paragraphs (k)(1) through(k)(3) of this section apply to each BLDS.
*  *  *  *  *
      (n) The owner or operator of a kiln or in-line kiln raw mill shall install a CEMS to continuously measure mercury emission rates in accordance with Performance Specification 12A (40 CFR part 60, appendix B).  The owner or operator shall operate and maintain each CEMS according to the quality assurance requirements in Procedure 1 of 40 CFR part 60, appendix F.
	(o) The owner or operator of any portland cement plant subject to the PM limit (lb/ton of clinker) for new or existing area sources in §63.1343(d) or (e) shall:
	 (1)  Install, calibrate, maintain and operate a permanent weigh scale system, or use another method approved by the Administrator, to measure and record weight rates in tons-mass per hour of the amount of clinker produced.  The system of measuring hourly clinker production must be maintained within +-5 percent accuracy. The use of a system that directly measures kiln feed rate and uses a conversion factor to determine the clinker production rate is an acceptable method.
            (2)  Record the daily clinker production rates and kiln feed rates.
      (p) The owner or operator of a kiln or clinker cooler using a PM continuous emission monitoring system (CEMS) to demonstrate compliance with the particulate matter emission limit in §63.1343 must install, certify, operate, and maintain the CEMS as specified in paragraphs (p)(1) through (p)(3) of this section.
       (1)  The owner or operator must conduct a performance evaluation of the PM CEMS according to the applicable requirements of §60.13, Performance Specification 11 of appendix B of part 60, and Procedure 2 of appendix F to part 60.
      (2)  During each relative accuracy test run of the CEMS required by Performance Specification 11 of appendix B to part 60, PM and oxygen (or carbon dioxide) data must be collected concurrently (or within a 30-to 60-minute period) during operation of the CEMS and when conducting performance tests using the following test methods:
      (i)  For PM, Method 5 or 5B of appendix A-5 to part 60 or Method 17 of appendix A-6 to part 60.
      (ii)  For oxygen (or carbon dioxide), Method 3, 3A, or 3B of appendix A-2 to part 60, as applicable.
      (3)  Procedure 2 of appendix F to part 60 for quarterly accuracy determinations and daily calibration drift tests.   The owner or operator must perform Relative Response Audits annually and Response Correlation Audits every 3 years.
      (q)  The owner or operator of an affected source subject to limitations on emissions of HCl shall:
      (i) Continuously monitor compliance with the HCl limit by operating a continuous emission monitor in accordance with Performance Specification 15 of part 60, appendix B. The owner or operator shall operate and maintain each CEMS according to the quality assurance requirements in Procedure 1 of 40 CFR part 60, appendix F, or
      (ii)  Monitor your wet scrubber parameters as specified in 40 CFR part 63 subpart SS.
       (r)  The owner or operator complying with the total organic HAP emissions limits of §63.1343 shall continuously monitor THC according to paragraphs (r)(1) through (r)(3) of this section to demonstrate continuous compliance with the emission limits for total organic HAP.
      (1) 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 found in the general provisions, subpart A of the part.
      (2)  Calculate the three-hour average THC concentration as the average of 180 successive one-minute average THC readings. The three-hour average THC concentration shall not exceed the average THC concentration established during the initial performance tests for total organic HAP. 
	10.  Section 63.1351 is amended by revising paragraph (d) and adding paragraphs (e) and (f) to read as follows:
§63.1351  Compliance dates.
*   *   *   *   *
      (d)  The compliance date for a new source which commenced construction after December 2, 2005, and before December 20, 2006 to meet the THC emission limit of 6 ppmvd or the mercury standard of 14 lb/MM tons clinker will be December 21, 2009, or the effective date of these amendments, whichever is later.
      (e)  The compliance data for existing sources with the revised PM, mercury, THC, and HCl emissions limits will be 3 years from the effective data of these amendments.
      (f)  The compliance date for new sources not subject to paragraph (d) of this section will be the effective date of the final rule or startup, whichever is later.
	11.  Section 63.1354 is amended by adding paragraph (b)(9)(vi) to read as follows:
§63.1354  Reporting requirements.
*  *  *  *  *
	(b )* * *
	(9) * * *
	(vi)	 Monthly rolling average mercury concentration for each kiln and in-line kiln/raw mill. 
*  *  *  *  *
      12.  Section 63.1355 is amended by revising paragraph (e) to read as follows:
§63.1355  Recordkeeping requirements.
*  *  *  *  *
	(e)  You must keep records of the daily clinker production rates and kiln feed rates for area sources. 
*  *  *  *  *
	13.  Section 63.1356 is revised to read as follows: 
§63.1356 Sources with multiple emission limits or monitoring requirements.   
      If an affected facility subject to this subpart has a different emission limit or requirement for the same pollutant under another regulation in title 40 of this chapter, the owner or operator of the affected facility must comply with the most stringent emission limit or requirement and is exempt from the less stringent requirement. 
	14.  Table 1 to Subpart LLL of Part 63 is revised to read as follows:
Table 1 to Subpart LLL of Part 63 -- Applicability of General Provisions
                                   Citation
                                  Requirement
                            Applies to Subpart LLL
                                       
                                    Comment
63.1(a)(1) - (4)
Applicability
Yes

63.1(a)(5)

No
[Reserved]
63.1(a)(6) - (8)
Applicability
Yes

63.1(a)(9)

No
[Reserved]
63.1(a)(10) - (14)
Applicability
Yes

63.1(b)(1)
Initial Applicability Determination
No
§63.1340 specifies applicability.
63.1(b)(2) - (3)
Initial Applicability Determination
Yes

63.1(c)(1)
Applicability After Standard Established
Yes

63.1(c)(2)
Permit Requirements
Yes
Area sources must obtain Title V permits.
63.1(c)(3)

No
[Reserved]
63.1(c)(4) - (5)
Extensions, Notifications
Yes

63.1(d)

No
[Reserved]
63.1(e)
Applicability of Permit Program
Yes

63.2
Definitions
Yes
Additional definitions in §63.1341.
63.3(a) - (c)
Units and Abbreviations
Yes

63.4(a)(1) - (3)
Prohibited Activities
Yes

63.4(a)(4)

No
[Reserved]
63.4(a)(5)
Compliance date
Yes

63.4(b) - (c)
Circumvention, Severability
Yes

63.5(a)(1) - (2)
Construction/Reconstruction
Yes

63.5(b)(1)
Compliance Dates
Yes

63.5(b)(2)

No
[Reserved]
63.5(b)(3) - (6)
Construction Approval, Applicability
Yes

63.5(c)

No
[Reserved]
63.5(d)(1) - (4)
Approval of Construction/Reconstruction
Yes

63.5(e)
Approval of Construction/Reconstruction
Yes

63.5(f)(1) - (2)
Approval of Construction/Reconstruction
Yes

63.6(a)
Compliance for Standards and Maintenance
Yes

63.6(b)(1) - (5)
Compliance Dates
Yes

63.6(b)(6)

No
[Reserved]
63.6(b)(7)
Compliance Dates
Yes

63.6(c)(1) - (2)
Compliance Dates
Yes

63.6(c)(3) - (4)

No
[Reserved]
63.6(c)(5)
Compliance Dates
Yes

63.6(d)

No
[Reserved]
63.6(e)(1) - (2)
Operation & Maintenance
Yes

63.6(e)(3)
Startup, Shutdown Malfunction Plan
Yes

63.6(f)(1) - (3)
Compliance with Emission Standards
Yes





63.6(g)(1) - (3)
Alternative Standard
Yes

63.6(h)(1) - (2)
Opacity/VE Standards
Yes

63.6(h)(3)

Nos
[Reserved]




63.6(h)(4) - (h)(5)(i)
Opacity/VE Standards
Yes

63.6(h)(5)(ii) - (iv)
Opacity/VE Standards
No
Test duration specified in subpart LLL.
63.6(h)(6)
Opacity/VE Standards
Yes

63.6(h)(7)
Opacity/VE Standards
Yes

63.6(i)(1) - (14)
Extension of Compliance
Yes

63.6(i)(15)

No
[Reserved]
63.6(i)(16)
Extension of Compliance
Yes

63.6(j)
Exemption from Compliance
Yes

63.7(a)(1) - (3)
Performance Testing Requirements
Yes
§63.1349 has specific requirements.
63.7(b)
Notification
Yes

63.7(c)
Quality Assurance/Test Plan
Yes

63.7(d)
Testing Facilities
Yes

63.7(e)(1) - (4)
Conduct of Tests
Yes

63.7(f)
Alternative Test Method
Yes

63.7(g)
Data Analysis
Yes

63.7(h)
Waiver of Tests
Yes

63.8(a)(1)
Monitoring Requirements
Yes

63.8(a)(2)
Monitoring
No
§63.1350 includes CEMS requirements.
63.8(a)(3)

No
[Reserved]
63.8(a)(4)
Monitoring
No
Flares not applicable.
63.8(b)(1) - (3)
Conduct of Monitoring
Yes

63.8(c)(1) - (8)
CMS Operation/Maintenance
Yes
Temperature and activated carbon injection monitoring data reduction requirements given in subpart LLL.
63.8(d)
Quality Control
Yes

63.8(e)
Performance Evaluation for CMS
Yes
Performance specification supersedes requirements for THC CEMS.
63.8(f)(1) - (5)
Alternative Monitoring Method
Yes
Additional requirements in §63.1350(l).
63.8(f)(6)
Alternative to RATA Test
Yes

63.8(g)
Data Reduction
Yes

63.9(a)
Notification Requirements
Yes

63.9(b)(1) - (5)
Initial Notifications
Yes

63.9(c)
Request for Compliance Extension
Yes

63.9(d)
New Source Notification for Special Compliance Requirements
Yes

63.9(e)
Notification of Performance Test
Yes

63.9(f)
Notification of VE/Opacity Test
Yes
Notification not required for VE/opacity test under §63.1350(e) and (j).
63.9(g)
Additional CMS Notifications
Yes

63.9(h)(1) - (3)
Notification of Compliance Status
Yes

63.9(h)(4)

No
[Reserved]
63.9(h)(5) - (6)
Notification of Compliance Status
Yes

63.9(i)
Adjustment of Deadlines
Yes

63.9(j)
Change in Previous Information
Yes

63.10(a)
Recordkeeping/Reporting
Yes

63.10(b)
General Requirements
Yes

63.10(c)(1)
Additional CMS Recordkeeping
Yes
PS - 8A supersedes requirements for THC CEMS.
63.10(c)(2) - (4)

No
[Reserved]
63.10(c)(5) - (8)
Additional CMS Recordkeeping
Yes
PS - 8A supersedes requirements for THC CEMS.
63.10(c)(9)

No
[Reserved]
63.10(c)(10) - (15)
Additional CMS Recordkeeping
Yes
PS - 8A supersedes requirements for THC CEMS.
63.10(d)(1)
General Reporting Requirements
Yes

63.10(d)(2)
Performance Test Results
Yes

63.10(d)(3)
Opacity or VE Observations
Yes

63.10(d)(4)
Progress Reports
Yes

63.10(d)(5)
Startup, Shutdown, Malfunction Reports
Yes

63.10(e)(1) - (2)
Additional CMS Reports
Yes

63.10(e)(3)
Excess Emissions and CMS Performance Reports
Yes
Exceedances are defined in subpart LLL.
63.10(f)
Waiver for Recordkeeping/Reporting
Yes

63.11(a) - (b)
Control Device Requirements
No
Flares not applicable.
63.12(a) - (c)
State Authority and Delegations
Yes

63.13(a) - (c)
State/Regional Addresses
Yes

63.14(a) - (b)
Incorporation by Reference
Yes

63.15(a) - (b)
Availability of Information
Yes



      


      
	
	
	


      	
	
	
	

	

	
	
	
	
	
	
	
	


	

	
	
	
	
	

	
	
	
	
	

	
	
	
	
	
	
	
	
	
	
	
	
	
	
	

	
	
	
					
	
	
	
	



	

	
	
	
			
	
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