# National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing Industry and Standards of Performance for Portland Cement Plants > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2012-16166 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** July 18, 2012 - **Citation:** 77 FR 42368 ## Text ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 60 and 63 [EPA-HQ-OAR-2011-0817; FRL-9692-9] RIN 2060-AQ93 National Emission Standards for Hazardous Air Pollutants for the Portland Cement Manufacturing Industry and Standards of Performance for Portland Cement Plants AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rules on reconsideration. SUMMARY: The EPA is proposing amendments to the National Emission Standards for Hazardous Air Pollutants for the Portland cement industry for Portland cement plants issued under sections 112(d) of the Clean Air Act. Specifically, the EPA is proposing to amend the existing and new source standards for particulate matter (PM). The EPA is also proposing amendments with respect to issues on which it granted reconsideration on May 17, 2011. In addition, the EPA is proposing amendments to the new source performance standard for PM issued pursuant to section 111(b) of the Clean Air Act. These proposed amendments would promote flexibility, reduce costs, and ease compliance burdens. EPA is also addressing the remand of the emission standards in the NESHAP by the D.C. Circuit on December 9, 2011. Finally, the EPA is proposing to extend the date for compliance with the existing source national emission standards for hazardous air pollutants to September 9, 2015. DATES: Comments must be received on or before August 17, 2012. Any requests for a public hearing must be received by July 30, 2012. If the EPA holds a public hearing, the EPA will keep the record of the hearing open for thirty days after completion of the hearing to provide an opportunity for submission of rebuttal and supplementary information. 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 receives a copy of your comments on or before August 17, 2012. ADDRESSES: Submit your comments, identified by Docket ID Number EPA-HQ-OAR-2011-0817, by one of the following methods: • Federal Rulemaking Portal: http://www.regulations.gov . Follow the online instructions for submitting comments. • Agency Web site: http://www.epa.gov/oar/docket.html . Follow the instructions for submitting comments on the EPA Air and Radiation Docket Web site. • Email: a-and-r-docket@epa.gov . Include EPA-HQ-OAR-2011-0817 in the subject line of the message. • Fax: Fax your comments to: (202) 566-9744, Attention Docket ID Number EPA-HQ-OAR-2011-0817. • Mail: Send your comments to: The EPA Docket Center (EPA/DC), Environmental Protection Agency, Mailcode: 2822T, 1200 Pennsylvania Ave. NW., Washington, DC 20460, Attention: Docket ID Number EPA-HQ-OAR-2011-0817. 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 the EPA, 725 17th Street NW., Washington, DC 20503. • Hand Delivery or Courier: In person or by courier, deliver comments to the EPA Docket Center, EPA West (Air Docket), Room 3334, 1301 Constitution Ave. NW., Washington, DC 20460, Attention Docket ID Number EPA-HQ-OAR-2011-0817. Such deliveries are only accepted during the Docket's normal hours of operation (8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays), and special arrangements should be made for deliveries of boxed information. Please include two copies. Instructions: Direct your comments to Docket ID Number EPA-HQ-OAR-2011-0817. The EPA policy is that all comments received will be included in the public docket without change and may be made available online at http://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 http://www.regulations.gov or email. The http://www.regulations.gov Web site is an “anonymous access” system, which means the EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an email comment directly to the EPA without going through http://www.regulations.gov, your email 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, the 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 the EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, the 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. For additional information about the EPA public docket, visit the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm . Docket. The EPA has established a docket for this rulemaking under Docket ID Number EPA-HQ-OAR-2011-0817. All documents in the docket are listed in the http://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 http://www.regulations.gov or in hard copy at the EPA Docket Center, EPA West, Room 3334, 1301 Constitution Ave. NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the EPA Docket Center is (202) 566-1742. Note that information pertinent to the previous Portland cement rulemakings discussed in this document is contained in dockets EPA-HQ-OAR-2002-0051 and EPA-HQ-OAR-2007-0877. Public Hearing . If a public hearing is held, it will begin at 10:00 a.m. on August 2, 2012 and will be held at the EPA campus in Research Triangle Park, North Carolina, or at an alternate facility nearby. Persons interested in presenting oral testimony or inquiring as to whether a public hearing is to be held should contact Ms. Pamela Garrett, Office of Air Quality Planning and Standards, Sector Policies and Programs Division, Metals and Minerals Group (D243-01), U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711; email: garrett.pamela@epa.gov; telephone number: (919) 541-7966. Persons interested in presenting oral testimony or inquiring as to whether a public hearing is to be held should contact Ms. Garrett at least 2 days in advance of the potential date of the public hearing. FOR FURTHER INFORMATION CONTACT: Ms. Sharon Nizich, Office of Air Quality Planning and Standards; Sector Policies and Programs Division, Minerals and Manufacturing Group (D243-04); Environmental Protection Agency; Research Triangle Park, NC 27111; telephone number: (919) 541-2825; fax number: (919) 541-5450; email address: nizich.sharon@epa.gov . SUPPLEMENTARY INFORMATION: The information presented in this preamble is organized as follows: I. General Information A. Executive Summary B. Does this action apply to me? C. What should I consider as I prepare my comments to the EPA? D. Where can I get a copy of this document? II. Background Information A. What is the statutory authority for these proposed amendments? B. What actions preceded this proposed rule? III. Description of Proposed Amendments to Subpart LLL and Subpart F A. Reconsideration of Standards B. Mercury Standard C. THC Standard D. Proposed Amendments to Existing Source and New Source Standards for PM Under Section 112(d) and 111(b) E. Summary of Proposed Standards Resulting From Reconsideration F. Standards for Fugitive Emissions From Clinker Storage Piles G. Affirmative Defense to Civil Penalties for Exceedances Occurring During Malfunctions H. Continuously Monitored Parameters for Alternative Organic HAP Standard (With THC Monitoring Parameter) I. Allowing Sources With Dry Caustic Scrubbers to Comply With HCl Standard Using Performance Tests J. Alternative PM Limit K. Standards During Startup and Shutdown L. Coal Mills M. PM Standard for Modified Sources Under the NSPS N. Proposed NESHAP Compliance Date Extension for Existing Sources O. Eligibility to be a New Source IV. Other Proposed Testing and Monitoring Revisions V. Other Changes and Areas Where We Are Requesting Comment 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 health effects of these pollutants? VII. Statutory and Executive Order Reviews A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory 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 and Advancement Act J. Executive Order 12898: Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations I. General Information A. Executive Summary The EPA is proposing amendments to the emissions standards for hazardous air pollutants (HAP) and to the performance standards for Portland cement plants. These proposed amendments respond to petitions for reconsideration filed by the Portland cement industry and to a decision by the United States Court of Appeals for the District of Columbia Circuit (D.C. Circuit). These amendments, which are consistent with the CAA, if adopted, will also provide less costly compliance options and compliance flexibilities, and thereby result in cost savings for the Portland cement industry. This result would also be consistent with Executive Order 13563. The proposed amendments include a new compliance date for the PM, mercury, HCl, and THC existing source standards. (1) Purpose of the Regulatory Action a. Need for the Regulatory Action. The EPA is proposing amendments to the national emission standards for hazardous air pollutants (NESHAP) for the Portland cement source category and to the new source performance standards (NSPS) for Portland cement plants issued under sections 112(d) and 111(b) of the Clean Air Act (CAA). Section 112 of the CAA establishes a regulatory process to address emissions of HAP from stationary sources. After the EPA identifies categories of sources emitting one or more of the HAP listed in section 112(b) of the CAA, section 112(d) requires the EPA to promulgate technology-based NESHAP for those sources. Section 111 of the CAA requires that NSPS reflect the application of the best system of emission reductions achievable which, taking into consideration the cost of achieving such emission reductions, and any non-air quality health and environmental impact and energy requirements, the Administrator determines has been adequately demonstrated. This proposal addresses the remand by the D.C. Circuit in Portland Cement Ass'n v. EPA, 665 F. 3d 177 (D.C. Cir. 2011). In that case, the court upheld all of the EPA's methodology for establishing the Portland cement NESHAP, denied all petitions for review challenging the NSPS, but also held that the EPA had arbitrarily denied reconsideration of the NESHAP to take into account the effect of the EPA's Nonhazardous Secondary Materials (NHSM) rule on the standards. The NHSM rule, issued after the NESHAP was promulgated, had the effect of reclassifying some cement kilns as commercial and industrial solid waste incinerators (CISWI) and thus could have an effect on the standards. The proposal also addresses technical issues with respect to the standard for PM in both the NESHAP and the NSPS that have emerged since these rules' promulgation. We are proposing to amend the standard for PM, and also proposing to amend various implementation requirements in a way that would provide more compliance flexibilities. In addition, the proposal addresses the issues on which the EPA previously granted reconsideration. b. Legal Authority for the Regulatory Action. These proposed amendments implement sections 112(d) and 111(b) of the CAA. (2) Summary of Major Proposed Provisions a. PM (PM) Emission Standards. The EPA is proposing changes to the emission standards for PM that potentially make available compliance alternatives unavailable under the promulgated existing source standards. The promulgated rule requires compliance to be demonstrated using a Continuous Emission Monitoring System (CEMS) (see section 63.1348 (75 FR 55056)). Based on the information the EPA now has, we believe that it may be problematic for a PM CEMS to meet the mandated Performance Specification 11 (PS 11) correlation requirements complying with the promulgated PM standards. (See section III.D.) As a consequence, the EPA is proposing to amend the existing and new source PM standards in the NESHAP to require manual stack testing in lieu of PM CEMS for compliance determinations. An additional consequence of this proposed change of compliance measurement methods is that the EPA is proposing to change the averaging time and numeric emissions value of those standards. The EPA is proposing amended PM standards under the NESHAP for existing sources of 0.07 pounds per ton (lb/ton) clinker based on manual stack testing, (from 0.04 lb/ton in the 2010 rule, 30-day average with a PM CEMS) and 0.02 lb/ton clinker for new sources based on stack testing (from 0.01 lb/ton in the 2010 rule, 30-day average with a PM CEMS). The EPA is proposing amended PM standards under the NSPS for modified sources of 0.07 lb/ton clinker based on manual stack testing, (from 0.01 lb/ton in the 2010 rule, 30-day average with a PM CEMS) and 0.02 lb/ton clinker for new and reconstructed sources based on stack testing (from 0.01 lb/ton in the 2010 rule, 30-day average with a PM CEMS). The EPA is further proposing that a site-specific parametric operating limit be established, that there be continuous monitoring of that parametric limit using a PM CPMS, that an exceedance of that site-specific operating limit be reported as a deviation, triggering corrective action including conducting a Method 5 performance test within 45 days. Further, multiple deviations from the parametric limit can constitute a violation of the emissions standard. b. Response to Remand. Consistent with the court's remand, the EPA has removed all the CISWI kilns from the database used to set the 2010 existing source standards for PM, mercury, hydrochloric acid and total hydrocarbons (THC). The EPA then recalculated existing source floors for each of these pollutants, and determined what standards to propose in light of that analysis. This analysis informed the level of the proposed standards for PM just discussed. The resulting standards are discussed immediately below. c. Other Emissions Standards. The EPA is not proposing any changes to the existing source standards for mercury, total THC or hydrogen chloride (HCl). The reasons are set out in sections III A, B and C below. With respect to new source standards, under section 112(d)(3) of the CAA, new source floors can be based on the performance of the “best controlled similar source.” A CISWI cement kiln is a similar source for purposes of this provision. The EPA, therefore, is not proposing to amend any of the new source floors or standards for mercury, THC or HCl where the best performing source in the database used to set the standards was a CISWI cement kiln. The EPA is also proposing to amend the alternative standard for organic HAP, whereby organic HAP are measured directly. To avoid a situation where the alternative organic standard level is lower than the practical quantitation limit of the relevant analytic methods, the EPA is proposing to increase the alternative organic HAP standard from 9 parts per million (ppm) to 12 ppm. See additional discussion in section III.H below. d. Standards during Startup and Shutdown. In the final 2010 NESHAP, the EPA established specific numerical standards for startup and shutdown for each pollutant to be measured using a CEMS over an accumulative 7-day rolling average. Because raw materials (the source of most cement kiln air emissions) are not introduced into cement kilns during startup and shutdown, cement kilns' emissions during these periods should be appreciably lower than the level of the standards. The EPA is, therefore, proposing that sources monitor compliance with these standards via recordkeeping. e. Proposed Compliance Dates. The EPA is proposing that the compliance date for all existing source standards including standards for PM, mercury, HCl and THC, clinker piles and the standards for startup and shutdown be extended to September 9, 2015. The EPA believes that the proposed change to the PM standard makes possible compliance alternatives unavailable under the promulgated existing source standards) and that an extension until September 9, 2015, is the period in which these new compliance strategies can be implemented most expeditiously. f. The EPA is also taking action on the remaining issues on which it granted reconsideration on May 17, 2011. (3) Costs and Benefits The following table 1 summarizes the costs and emissions reductions of this proposed action. Table 1—Costs and Emissions Reductions of Proposed Amendments Relative to the 2010 Rule a b c d e Proposed amendment Capital cost Annualized cost Emissions reduction Revised PM standard −$18,640,106 −$4,200,000 −135 tons/yr (emissions increase). Replace PM CEMS with PM CPMS 0 −7,980,000 0 Total −18,640,106 −12,180,000 a See section III below for further discussion of impacts of the proposed amendments. b Negative numbers indicate cost savings or emissions increase. All costs are in 2005 dollars. c We also estimate that there will be a one-time cost of $25,000 for each facility to develop the calculation that will allow them to demonstrate compliance during periods of startup and shutdown. d Emissions reductions are the total relative to the 2010 rule once full compliance is achieved in 2015. e Full compliance costs will not occur until September 9, 2015. The cost information in Table 1 is in 2005 dollars at a discount rate of 7 percent. The net change in annualized costs in 2015 is a $12.2 million savings compared to the 2010 rule. The EPA did not have sufficient information to quantify the overall change in benefits or costs for 2013 to 2015 that might arise due to the proposed change in compliance dates. 4. Summary of Proposed Standards The following Table 2 shows the proposed standards. Table 2—Proposed Existing and New Source Standards Pollutant Existing source standard New source standard Mercury 55 lb/MM tons clinker 21 lb/MM tons clinker. THC 24 ppmvd 24 ppmvd. PM 0.07 lb/ton clinker (3-run test average) 0.02 lb/ton clinker (3-run test average). HCl 3 ppmvd 3 ppmvd. Organic HAP (alternative to Total Hydrocarbon) 12 ppmvd 12 ppmvd. B. Does this action apply to me? Categories and entities potentially regulated by this final rule include: Category NAICS Code 1 Examples of regulated entities Industry 327310 Portland cement manufacturing plants. Federal government Not affected. State/local/tribal government Portland cement manufacturing plants. 1 North American Industry Classification System. This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be regulated by this action. To determine whether your facility will be regulated by this action, you should examine the applicability criteria in 40 CFR 60.60 (subpart F) or in 40 CFR 63.1340 (subpart LLL). If you have any questions regarding the applicability of this final action to a particular entity, contact the person listed in the preceding FOR FURTHER INFORMATION CONTACT section. C. What should I consider as I prepare my comments to the EPA? Submitting CBI Do not submit information containing CBI to the EPA through http://www.regulations.gov or email. Clearly mark the part or all of the information that you claim to be CBI. For CBI information on a disk or CD-ROM that you mail to the 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. If you submit a CD-ROM or disk that does not contain CBI, mark the outside of the disk or CD-ROM clearly that it does not contain CBI. Information not marked as CBI will be included in the public docket and the EPA's electronic public docket without prior notice. Information marked as CBI will not be disclosed except in accordance with procedures set forth in 40 CFR part 2. 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, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, Attention Docket ID Number EPA-HQ-OAR-2011-0817. D. Where can I get a copy of this document? In addition to being available in the docket, an electronic copy of this proposal will also be available on the World Wide Web (WWW) through the EPA's Technology Transfer Network (TTN). Following signature by the EPA Administrator, a copy of this proposed action will be posted on the TTN's policy and guidance page for newly proposed or promulgated rules at the following address: http://www.epa.gov/ttn/oarpg. The TTN provides information and technology exchange in various areas of air pollution control. II. Background Information A. What is the statutory authority for these proposed amendments? Section 112 of the CAA establishes a regulatory process to address emissions of HAP from stationary sources. After the EPA has identified categories of sources emitting one or more of the HAP listed in section 112(b) of the CAA, section 112(d) requires us to promulgate NESHAP for those sources. For “major sources” that emit or have the potential to emit 10 tons per year (tpy) or more of a single HAP or 25 tpy or more of a combination of HAP, these technology-based standards must reflect the maximum reductions of HAP achievable (after considering cost, energy requirements and non-air quality health and environmental impacts) and are commonly referred to as maximum achievable control technology (MACT) standards. The statute specifies certain minimum stringency requirements for MACT standards, which are referred to as “floor” requirements. See CAA section 112(d)(3). Specifically, for new sources, the MACT floor cannot be less stringent than the emission control that is achieved in practice by the best controlled similar source. The MACT standards for existing sources can be less stringent than standards for new sources, but they cannot be less stringent than the average emission limitation achieved by the best-performing 12 percent of existing sources (for which the Administrator has emissions information) in the category or subcategory (or the best-performing five sources for categories or subcategories with fewer than 30 sources. In developing MACT, we must also consider control options that are more stringent than the floor. We may establish standards more stringent than the floor based on the consideration of the cost of achieving the emissions reductions, any non-air quality health and environmental impacts, and energy requirements. See CAA section 112(d)(2). 1 1 Section 112(d)(7) states that “[n]o other emission standard * * * under this section shall be interpreted, construed or applied to diminish or replace the requirements of a more stringent emission limitation or other applicable requirement established pursuant to section 7411 of this title, part C or D of this subchapter, or other authority of this chapter or a standard issued under State authority.” This provision indicates that a section 112(d) standard does not “trump” any standard established under other authority which is more stringent. Section 112(d)(7) does not bar the EPA from amending section 112(d) standards to correct technical deficiencies. Section 111(b) requires the EPA to set standards for emissions that “reflect the degree of emission limitation achievable through the application of the best system of emission reduction.” See CAA section 111(a)(1). In contrast to the NESHAP floor setting process, NSPS requires the EPA to take into account the “cost of achieving” emissions reductions, as well as health, environmental, and energy considerations. Id. B. What actions preceded this proposed rule? The history of this proposed rule, commencing with the 1999 standards and proceeding through the amendments issued in September 2009, is set out in detail in 75 FR 54970 (Sept 9, 2010). Various parties filed petitions for reconsideration of aspects of those amendments. On May 17, 2011, the EPA granted reconsideration of various issues, and denied the petitions to reconsider as to the remaining issues. See 76 FR 28318 (May 17, 2011). On December 9, 2011, the D.C. Circuit issued an opinion upholding the NESHAP itself (as well as the section 111 NSPS), but found that the EPA had arbitrarily failed to grant reconsideration to consider the effect of the EPA's NHSM rule on the standards (76 FR 15456 (March 21, 2011)), which rule had the effect of reclassifying some cement kilns as commercial and solid waste incinerators. See Portland Cement Ass'n v. EPA, 665 F. 3d 177, 186-189 (D.C. Cir. 2011). That court did not stay the standards for PM, mercury, HCl or THC, but did stay the standard for clinker piles pending the conclusion of the reconsideration process. See 665 F. 3d at 194. In this action, the EPA is responding to the court's remand. For existing sources, the EPA is doing so by removing all kilns classified as commercial and industrial solid waste incinerators from the data used to establish the 2010 NESHAP standards. The EPA is then recalculating each of the floors based on this revised dataset and making beyond-the-floor determinations based on the recalculated floors. The EPA believes that this approach is fully responsive to the court's remand. See 665 F. 3d at 188 where the court referred favorably to this type of recalculation. For new sources, the EPA is basing floors on the performance of the best performing similar source. III. Description of Proposed Amendments to Subpart LLL and Subpart F A. Reconsideration of Standards As just noted, in Portland Cement Association v. EPA, the D.C. Circuit upheld all of the EPA's methodology for establishing the Portland cement NESHAP, but remanded the standards so that the EPA could account for the effects of the EPA's NHSM rule. This rule, adopted after promulgation of the Portland cement NESHAP, had the effect of reclassifying certain cement kilns as commercial and industrial incinerators because they combust “solid waste” as defined by that rule. See 665 F. 3d at 185-189. Applying that definition, the EPA has determined that there are 24 cement kilns which combust solid waste. See 76 FR 28322 and Memorandum “Combustion in a Cement Kiln and Cement Kilns' Use of Tires as Fuel” (April 25, 2011) (“April 25 memorandum”); see also 76 FR 80452 (Dec. 23, 2011) where the EPA identified 23 of the 24 kilns as commercial incinerators as were identified in the April 25 memorandum. The 24th kiln was identified as a CISWI kiln after development of the April 25, 2011, memorandum, but the addition of this kiln did not affect the calculations contained in the May 17, 2011 notice (CISWI Data Revisions since Reconsideration Proposal, docket EPA-HQ-OAR-2003-0119). Although the EPA has proposed to reconsider certain narrow aspects of the NHSM rule, see 76 FR 80598 (Dec. 23, 2011), this count remains unchanged by any of the issues being considered in the reconsideration of the NHSM rule. This is because either the types of secondary materials being addressed in that reconsideration are not combusted by cement kilns or the EPA has already accounted for those materials in its April 25 memorandum analysis. See 76 FR 28319 (May 17, 2011). Specifically, in the NHSM reconsideration proposal, the EPA proposed to clarify that clean cellulosic biomass and clean construction and demolition wood are not solid wastes when burned for energy recovery and that unused, off-specification tires are not wastes when burned for energy recovery. The EPA's analysis underlying its April 25, 2011, memorandum already reflects that these non-hazardous secondary materials are not wastes when burned by cement kilns for energy recovery. The EPA expects the reconsideration of the NHSM rule to be completed before taking final action on this proposed rule and the EPA will account for any changes resulting from the reconsidered final NHSM rule when it takes final action here. 2 2 The EPA has also conducted a bounding analysis of potential floors by removing from the data base all cement kilns that burn any type of secondary material for energy recovery (so that there is no possibility that any CISWI kiln is in the bounding analysis database). Under this analysis, the existing source section 112 floor for HCl was unchanged, the existing source floor for PM was essentially unchanged, the existing source floor for THC becomes more stringent (as in the April 25, 2011, analysis), and the existing source mercury floor increases from 55 lb/MM ton clinker to 66 lb/MM ton clinker. However, even in this case, a beyond-the-floor mercury limit of 55 lb/MM tons clinker would be cost effective and the EPA would propose the same standards as under this proposal if this bounding analysis were used in place of the analysis described in the text. The EPA, thus, does not believe that the precise count of CISWI kilns will affect the outcome of this rulemaking. See Bounding Analysis for Portland Cement MACT Floors, May 14, 2012. 1. Existing Source Floors. We removed the 24 CISWI kilns from the database used to establish existing source standards and recalculated floors for existing sources. Under this analysis, the existing source floor for mercury increased from 55 lb/million (MM) tons clinker to 58 lb/MM tons clinker, the existing source floor for PM increased from 0.04 lb/ton clinker to 0.05 lb/ton clinker, the existing source floor for THC decreased to 15 parts per million by volume, dry (ppmvd), and the existing source floor for HCl stayed the same at 3 ppmvd. As explained in section B below, the EPA is proposing to establish a beyond the floor standard for mercury of 55 lb/MM tons clinker. Moreover, for reasons independent of this analysis, the EPA is proposing to amend the existing and new source NESHAP for PM. See section D below. The EPA is not proposing to amend the HCl standard or the THC standard. 2. New Source Standards. With respect to new source standards, the EPA does not believe that any reclassification and reanalysis is necessary under the court's opinion. New source floors can be based on the performance of “the best controlled similar source”, as opposed to existing source floors which must reflect performance of sources “in the category or subcategory”. See CAA section 112(d)(3) and (d)(3)(A). A CISWI cement kiln is similar to a non-CISWI cement kiln since the device is a cement kiln. Equally important, burning secondary materials for energy recovery does not significantly alter a cement kiln's HAP emission profile. See 76 FR 28320 (May 17, 2011) (documenting both the basis for this conclusion and the cement industry's agreement with it). 3 4 3 The EPA is thus not reopening the new source standards (with the exception of the PM standard, which the EPA is proposing to amend). We will take comment on whether CISWI cement kilns can be considered a “similar source” under section 112(d)(3) and whether retention of the 2010 new source standards on this basis is consistent with the D.C. Circuit's opinion. The EPA will not consider comments challenging the data and methodology for the new source standards since these are unchanged from the 2010 rule and the EPA is not reexamining any of these issues. 4 If the EPA were to reconsider the new source standards by removing the 24 CISWI kilns from the database, then the mercury new source floor increased from 21 to 24 lb/MM tons clinker, the THC new source floor decreased from 24 to 11 parts per million by volume dry (ppmvd), and the PM and HCl new source floor stayed the same at 0.01 lb/ton clinker and 3 ppmvd, respectively (see Memorandum, Revised Portland Cement NESHAP with CISWI kilns removed, March 21, 2011). However, as explained in the text, because CISWI cement kilns are “similar sources” for purposes of establishing NESHAP new source standards, the EPA is not relying on this analysis here. B. Mercury Standard 1. New Source Standard. As explained above, the new source standard is based on the performance of the best performing similar source. 2. Existing Source Standard. As noted above, the recalculated existing source floor is 58 lb/MM tons clinker produced. The EPA is proposing a beyond-the-floor standard of 55 lb/MM ton clinker produced, the level of the 2010 final standard. As described below, the only difference in cost between the two levels is the incremental cost of removing slightly more mercury, which is estimated at $2,000/lb of mercury removed. This is because the control equipment needed for mercury would not alter, would not need to be sized differently, and would need to perform on average nearly identically at either a 55 lb/MM tons clinker or a 58 lb/MM tons clinker level. That is, in planning compliance, kilns would calibrate to achieve an average performance of 34.1 lb/MM tons clinker for a standard of 58 lb/MM tons clinker, and 31.7 for a standard of 55 lb/MM tons clinker, which translates to an additional reduction of 2.4 lb/MM tons of clinker per year. This equates to an estimated 180 pounds of nationwide mercury emissions per year, incremental to the recalculated floor. To achieve this additional reduction, we estimated an additional cost of approximately $355,000 for the industry, the cost of purchasing additional carbon injection materials. This equates to a cost-effectiveness of $2,000/lb of mercury reduction per year. This is the incremental cost of going from the recalculated floor of 58 lb/MM tons clinker to the proposed 55 lb/MM tons clinker. Because this is the same level as the 2010 rule, there are no incremental costs or emissions impacts when compared to the 2010 rule. See section 8.2, Portland Cement Reconsideration Technical Support Document. Moreover, this reduction is highly cost-effective. A cost effectiveness value of $2,000/lb. mercury is considerably less than values the EPA have found to be cost effective for removal of mercury in other air toxics rules. For example, in the National Emission Standards for Hazardous Air Pollutants: Mercury Emissions from Mercury Cell Chlor-Alkali Plants, the cost effectiveness was found to be between $13,000 to $31,000 per pound for the individual facilities (see Supplemental proposed rule, 76 FR 13858 (March 14, 2011)). The EPA also does not see any adverse energy or non-air quality health or environmental consequences of a 55 lb/MM tons clinker beyond-the-floor standard. We are not proposing a beyond the floor level below 55 lb/MM tons clinker for the same reasons given in the 2010 final rule—in particular the possibility that a lower standard could force some kilns to find alternative sources of limestone, at enormous cost and disruption. See 75 FR 54980 (September 9, 2010). C. THC Standard The THC data for the 2010 standard consist of CEMS data for 15 kilns. After removing the four CISWI kilns, nine kilns remain. Thus, the MACT floor kilns consisted of 12 percent of these nine kilns, or two kilns. The top two kilns were Suwannee and Holcim. As explained above, when CISWI sources are removed from the database for the 2010 standards, the existing source floor for THC becomes more stringent from 24 ppmvd to 15 ppmvd, and the new source standard would drop from 24 ppmvd to 11 ppmvd. This change results from removing from the database a CISWI cement kiln (the Lehigh Union Bridge kiln) with the lowest daily average performance but with more associated variability than the other kilns with the next highest daily average performance. See also 76 FR 28322 (May 17, 2011) n. 11 and 665 F. 3d at 188. However, notwithstanding this calculation, the EPA is not proposing to reduce the level of either the new source or the existing source THC standard. 1. New Source Standard. As just explained, the new source standard can be based on performance of a “best controlled similar source”, so there is no reason under the statute or the court's remand to amend the new source THC standard. The standard is also technically appropriate. See 75 FR 54981 (September 9, 2010) (explaining basis for the THC new source standard, which discussion is summarized below for the readers' convenience). Removing the CISWI Union Bridge kiln as the best performing new source would leave the Suwannee kiln as the lowest emitter based on its daily average THC emissions. See Portland Cement Reconsideration Technical Support Document (TSD), section 8.4, which is available in this rulemaking docket. This kiln has higher average emissions than the Union Bridge kiln (that is, its daily average emissions are higher than the Union Bridge kiln). This kiln thus emits more THC than the Union Bridge kiln, so the EPA identified the kiln emitting less THC on average—the Union Bridge kiln—to be the best performer. The Suwannee kiln has less measured variability than the Union Bridge kiln, but also has hundreds of fewer observations. For this reason, the EPA considered the Union Bridge kiln to be more representative of variability, and used its 99th percentile performance as the measure of performance of the best performing similar source in establishing the new source standard. See 75 FR 54981 (September 9, 2010). 5 5 For purposes of comparing the relative variability of the THC CEMS data for each of the kilns in our THC data set, we used the ratio of the 99th percentile for each kiln divided by its daily average. A ratio of 1.0 indicates no variability. As the ratio increases, variability increases. See Portland Cement Reconsideration TSD, section 8.4, which is available in this rulemaking docket. 2. Under the calculation described above, the existing source floor would be reduced from 24 ppmvd to 15 ppmvd. Subject to any comments the EPA receives on this proposed action, the EPA believes that such a floor level would not be technically appropriate. It omits the variability of the similar source with the best average performance for THC (the Union Bridge kiln), and so may not be fully representative of variability of best performing sources. As noted above, cement kiln HAP emissions are not appreciably affected by burning secondary materials for energy recovery so the Union Bridge's variability is representative of cement kiln variability. In addition, as noted above, the number of daily observations for the Union Bridge kiln is among the most robust in the database, containing over 3 times the number of observations as the next best performing cement kiln. Thus, there is a “demonstrated relationship” between the variability of the Union Bridge kiln and the variability of the best performing sources in the existing source floor pool. Sierra Club v. EPA, 479 F. 3d 875, 882 (D.C. Cir. 2007). The EPA consequently believes it is technically justified to consider the Union Bridge kiln's variability in estimating the variability of the best performing cement kilns for THC emissions. If the variability of the Union Bridge kiln is included along with the variability of the two best performing cement kilns, and applied to the two best performing cement kilns' performance, the floor would be 24 ppm, which the EPA is proposing as a floor. See Portland Cement Reconsideration TSD, section 8.4. This is the level of the 2010 standard. 3. Beyond the floor standards. The EPA is not proposing a beyond the floor THC standard for existing cement kiln sources. The reasons given in the rulemaking remain valid. See 75 54983 (September 9, 2010); 74 FR 21153 (May 6, 2009). We especially note that a more stringent standard for THC would force the increased use of energy-intense control technologies like regenerative thermal oxidizers (RTO) which have negative environmental implications, notably increased emission of carbon dioxide (CO 2 ) and other greenhouse gases, as well as increased emissions of nitrogen oxide (NO X ), carbon monoxide, sulfur dioxide (SO 2 ) and PM 10 . See 74 FR 21153 (May 6, 2009). 6 These devices are also extremely costly and not cost-effective. See 74 FR 21153 (May 6, 2009). For a description of the costs, energy requirements and environmental impacts of RTO, see Summary of Environmental and Cost Impacts for Final Portland Cement NESHAP and NSPS, August 6, 2010, docket no. EPA-HQ-OAR-2002-0051-3438. For all these reasons, the EPA does not consider a beyond-the-floor standard for THC to be justified under section 112(d)(2). Consequently, the EPA is not proposing a beyond-the-floor standard for THC for existing sources. 7 6 The EPA estimates that each thermal oxidizer emits an added increment of 0.02 tons of CO 2 for each ton of clinker produced. A typical kiln producing 1.2 million tons of clinker per year and controlled by an RTO would emit an additional 24,000 tons of CO 2 per year. See RTO Secondary Impacts, May 16, 2012, in this rulemaking docket. 7 The EPA is also proposing to amend the alternative standard for organic HAP under which organic HAP is measured directly. See section I below. D. Proposed Amendments to Existing Source and New Source Standards for PM Under Section 112(d) and 111(b) Based largely on developments which have occurred after the EPA granted reconsideration on certain aspects of the NESHAP 8 , the EPA is proposing revisions to the testing and monitoring methods used to demonstrate continuous compliance with the existing and new source PM emissions standards and is proposing changes to the averaging time, level, and compliance demonstration for those standards. The EPA has also removed all CISWI kilns from the data base used to establish the standards for PM and used this revised data base in determining the level of the standard, consistent with the court's remand. We explain these proposed changes below. 8 On November 15, 2011, Holcim (US) Inc., a domestic cement company, submitted a petition for reconsideration to the EPA requesting that the EPA reconsider and stay the NESHAP PM standard. The basis for the petition was CEMS data for PM from four of Holcim's kilns (some of which are either waste-burning or hazardous waste burning). Petition pp. 5-6. This information was collected commencing in January 2011. Since the information in the petition was gathered outside the time period mandated by section 307(d)(7)(B) of the Act—even assuming it was impractical to raise the objection during the public comment period, the grounds arose outside the time period for judicial review which ended in November 2010. Thus, the EPA believes that it is not compelled to grant this petition. Moreover, as discussed in the text below, because the EPA is proposing to no longer use a CEMS-based regime for the PM standard, the Holcim information is no longer of direct relevance in setting the level of the PM standard. A further issue with the data is that they were not obtained using CEMS calibrated according to PS-11, the protocol specified in the rule. Accordingly, the EPA is not basing its proposal of a revised PM standard on these data. The EPA is not, however, taking final action on the Holcim petition at this time, but intends to do so in conjunction with the issuance of the final reconsideration rule. On January 17 2012, LaFarge Cement submitted a petition for reconsideration containing no new data or information but arguing that the Holcim petition justified reconsideration of the standards. The EPA believes that this petition is subsumed by the Holcim petition. In comments to the 2009 proposal, industry commenters maintained that there were several problems with implementing the monitoring requirements to demonstrate compliance using a PM CEMS and with the requirements to conduct a periodic audit of the PM CEMS in accordance with Performance Specification (PS) 11 of appendix B and Procedure 2 of appendix F to part 60. The EPA responded to these comments in the 2010 final rule. See 75 FR 55007 (September 9, 2010); NESHAP Response to Comment Document pp. 163-166. Since that time, the Portland cement industry has identified further technical issues associated with the current PM CEMS technology in satisfying PS 11 correlation requirements that have emerged as the industry has attempted to develop a CEMS-based compliance strategy for PM pursuant to the 2010 NESHAP. 1. PS 11. The EPA has continued to review the application of PM CEMS in relation to the procedures and acceptance criteria of PS 11, the protocol mandated by the promulgated rule. See section 63.1350(b)(1). PS 11 is structured differently than other PS that apply to validating the performance of gaseous pollutant CEMS. This is primarily because the pollutant, PM, is defined entirely by the test method specified by regulation to measure it. As the industry commenters note, there are no independent standard reference materials for PM concentrations as there are for gaseous pollutants (e.g., NIST traceable compressed gases for validating SO 2 or NO X instrumental measurements). The only reference standard for determining the PM concentration in an air or stack gas sample is the reference test method. In the case of the Portland cement NESHAP (and NSPS), the rule specifies the EPA Method 5 for measuring filterable PM concentration or mass rate (e.g., in mg/dscm or lb/hr). PS 11 provides procedures and acceptance criteria for validating the performance of several types of PM CEMS technologies. Although there are multiple instrument and data reporting operational performance checks in PS 11 that are similar in concept to those for gaseous pollutant CEMS, there is the principal PM CEMS performance requirement that is distinctly different. That requirement is the development of a site-specific PM CEMS correlation or mathematical response curve. There is a key procedural element to developing that correlation. That is, PS 11 requires that the source conduct multiple stack test runs using an EPA PM test method (e.g., Method 5) and simultaneously collect corresponding PM CEMS output data. PS 11, section 8.6, requires at least five test runs at each of three different operating (i.e., low, mid, and high PM concentration) conditions that range from 25 to 100 percent of allowable emissions, if possible, for a total of 15 or more test runs. Then the source must use the test method data and the corresponding PM CEMS output data to develop an equation (i.e., a calculated linear or nonlinear curve) that will be used to define the relationship between the PM CEMS output and the test method measured PM concentrations. Each site-specific correlation must meet several PS 11 acceptance criteria including limits on confidence interval and tolerance interval equating to ±25 percent of the applicable emissions limit. 2. Discussion of Technical Issues. A particular challenge in applying PM CEMS to source emissions monitoring is in measuring the very low PM concentrations associated with a low applicable emissions limits for PM precisely enough to meet the PS 11 correlation requirements. In addition to measurement uncertainty inherent in PM CEMS data, the measurement uncertainty associated with the reference test method (e.g., Method 5) is a significant contributor to successful development of a PM CEMS correlation regardless of the type of PM CEMS used. As noted above, PS 11 specifies acceptable criteria for a correlation directly related to the applicable emissions limit. The Portland cement NESHAP PM emissions limit for existing sources of 0.04 lb/ton of clinker equates to 5 to 8 mg/dscm, depending on production rate (assuming a typical total gas flow rate per clinker production rate). For a PM CEMS set up to measure compliance with a 5 to 8 mg/dscm equivalent limit, the inherent uncertainty associated with a 1 hour Method 5 measurement (±0.6 to 1.2 mg/dscm) would constitute more than half of the ±25 percent of the applicable PS 11 acceptance threshold (i.e., ±1.2 to 2.0 mg/dscm) of the mid-level PS 11 correlation test (i.e. the correlation for the middle of the three PS 11 correlation points). Although one can improve the method detection capabilities of the Method 5 or other filterable PM test method by increasing sampling volume and run time, uncertainties in measurement would remain. For example to achieve a practical quantitation limit of 1 mg/dscm, one would need to conduct a test run of 6 hours or longer. The measurement uncertainty associated with a 6-hour Method 5 test runs at this concentration would be ±0.01 to 0.2 mg/dscm. At this level, the uncertainty associated with the PM test method measurements alone would be about half of the correlation limit allowed in PS 11. The PS 11 correlation calculations would also have to account for any PM CEMS measurement uncertainty. Factoring in the inherent PM CEMS response variability and the uncertainty associated with the representative sampling (e.g., PM and flow stratification), we agree with commenters that trying to satisfy PS 11 at such low concentrations using 1 hour Method 5 test runs could be problematic. The same issue arises for the new source standard because of the lower limit of the new source standard. The industry also argued that the variable raw feed material and chemical additives used in cement production will lead to changes in particle size, refractive index, particle density, and other physical characteristics of the particulate in the exhaust stream. This is important, according to the comments, because correlations developed for the light scatter and scintillation PM CEMS technology may be adversely affected by these physical changes in particles irrespective of changes in mass emissions rates or concentrations. In developing the 2010 final rule, the EPA assumed that cement kilns would be using light-scatter or scintillation PM CEMS. 9 The output or response of these light based detectors is a function of the index of refraction or photoelectric effects and the size distribution of the particles in the exhaust stream. In addition to being more sensitive than opacity monitors, light based detectors provide several degrees of design freedom not applicable to opacity monitors. PM CEMS manufacturers account for characteristics such as light wavelength, scattering angle, and solid angle of detection in designing instruments with desired response features. These types of PM CEMS can be reliably calibrated per PS 11 where the relative characteristics (e.g., distribution of size, shape, and constituents) of the PM in the exhaust remain relatively constant. Such may be the case, for example, where the PM being measured is predominantly combustion ash from burning fossil fuels in a boiler or an electricity generating unit. 9 US EPA, CEMS Cost Model, July 2006. The dominant sources of PM from a cement kiln are not from fuel combustion but from processing raw materials. Cement kilns process mostly limestone with naturally occurring variability in component percentages. See 74 FR 21142 (May 6, 2009); 75 FR 54977 (September 9, 2010). Cement kiln operators also add other chemical additives in variable concentrations to produce certain product characteristics. See 74 FR 21142. As noted in the EPA's technology background documents (e.g., http://www.epa.gov/ttn/emc/cem/pmcemsknowfinalrep.pdf and http://www.epa.gov/ttn/emc/cem/r4703-02-07.pdf ), the correlations developed for light-scatter or scintillation PM CEMS devices may be adversely affected when there are changes in the particle structure, size, and other physical characteristics of the emissions. These changes in emissions characteristics can occur with the variability inherent in the composition of fuels and raw feed materials, with use of mixed multiple fuels, or with addition of chemical additives in various proportions. 10 10 Memorandum, from C. Oldham to B. Schell, Particulate Matter Continuous Emission Monitoring System (PM CEMS) Capabilities, June 13, 2012. This is an issue of special import for cement kilns. One can expect significant variations in particle size distribution and other particle characteristics in Portland cement kiln exhaust because of the complicating effects of variable content feed materials and chemical additives. That means that correlations developed for one set of conditions may not apply with changes in feed materials or under other operating conditions (e.g., different chemical additives). The EPA has investigated whether PM CEMS that work on principles other than light scattering could effectively measure cement kiln PM and be calibrated per PS 11 requirements. There is at least one other PM CEMS technology, beta attenuation PM CEMS, also referred to as beta gauge technology that is much less sensitive to changes in particle characteristics than are light based detectors. The beta attenuation PM CEMS extracts a sample for the stack gas and collects the PM on a filter tape. The device periodically advances the tape from the sampling mode to an area where the sample is exposed to Beta radiation. The detector measures the amount of beta radiation emitted by the sample and that amount can be directly related to the mass of PM on the filter. The majority of PM CEMS devices used to date by cement kilns are based on light scatter or scintillation detection. We understand that a few Portland cement operators have applied beta attenuation devices. Since the EPA premised the rule on use of a different type of PM CEMS, since there is minimal operating experience with beta gauge PM CEMS in this industry, and because we are not aware that the experience includes a beta gauge PM CEMS calibrated per PS 11, the EPA believes that some type of research effort involving testing would be needed before predicating a PM standard on use of a beta gauge PM CEMS. Such an effort is likely to take several years to implement. 11 11 We also note that PS 11 provides for means to minimize the effects of changing particle sizes, for example by developing multiple correlation curves, each of which requires 15 Method 5 test runs. The EPA did not consider such an approach in promulgating the rule and again, further technical work is needed to ascertain if such an approach would yield reliable results. These issues exacerbate the uncertainties of calibrating PM CEMS at the level of the 2010 p.m. standards noted above. Using data from longer Method 5 test runs will improve the probability of a PM CEMS meeting PS 11 correlation requirements but will also raise practicality concerns potentially without completely resolving the problems. Given the combination of the low emissions concentrations PM CEMS measurement uncertainty factors discussed above, the variability in composition of cement PM, and need for extraordinarily long test runs to reduce Method 5 uncertainty to a level that compensates sufficiently for the PM CEMS measurement uncertainty, the EPA believes that this correlation will not be technically or practically achievable for a significant number of cement kiln sources. 3. A monitoring approach alternative to PM CEMS and PS 11. To address technical issues associated with PM CEMS meeting PS 11 correlation requirements at low PM emissions concentrations from cement kilns and the potentially variable PM emissions characteristics expected from Portland cement kilns, the EPA is proposing to change the compliance basis for the PM emissions limit from PM CEMS and the 30-day average emissions calculation. For monitoring continuous compliance, the rule would require PM CEMS equipment but, as explained below, that equipment would be used for continuous parametric monitoring rather than for direct measure of compliance with the numerical PM emissions limit. The EPA is proposing to change the means of demonstrating compliance from PM CEMS to Method 5 stack testing. In applying Method 5, PM is withdrawn isokinetically from the source and collected on a glass fiber filter maintained at a temperature of 120 ± 14 °C (248 ± 25°F). The PM mass, which includes any material that condenses at or above the filtration temperature, is determined gravimetrically after the removal of uncombined water. Compliance with the numerical emissions limit is then based on an average of three 2-hour test runs rather than a 30-day average determined from PM CEMS data. The numerical level of the standard would change to reflect the different averaging period. See 75 FR 54988 (September 9, 2010) (explaining that more measurements of a properly designed and operated control device decreases measured variability since there are likely to be more measurements at the mean of performance); see also 75 FR 54975 (September 9, 2010) (explaining how this phenomenon is reflected in the Upper Prediction Limit (UPL) equation used to project variability, since the m term (i.e., the number of measurements) in the equation becomes larger with more observations resulting in a larger denominator and hence lower ultimate level). By changing from a 30-day average with potentially 720 hourly values to a three-run test average producing three test run values, we reviewed and revised the calculation of the PM emissions floor and standard, and consistent with the court's remand, removed all CISWI kilns from the database in doing so. In calculating the PM MACT floor, the best performing kilns used in the analysis changed as a result of removing the kilns identified as CISWI kilns. In addition, we realized that in the original analysis PM emissions data for a single kiln were inadvertently treated as test results for three different kilns. After making that correction and after eliminating kilns identified as CISWI, the number of kilns in the data set was reduced from 45 kilns to 28 kilns. Therefore, the best performing 12 percent was represented by four kilns. As a result of removing the CISWI kilns, two kilns which were not best performers in the 2010 dataset are now best performers. See TSD section 8.3 and Appendices E and F. As in the 2009 proposal, we used individual test run data from our best performing kilns and calculated the 99th confidence UPL. Rather than using m = 30 in the equation as we did in the 2010 final rule where compliance was based on a 30 day rolling average, see 75 FR 54988 (September 9, 2010), we used m = 3 consistent with the proposed requirement to determine compliance using a three run Method 5 test. Under this analysis, we determined the revised proposed PM MACT floor to be 0.07 lb/ton clinker produced when based on the three run Method 5 test. Beyond-the-floor standards do not appear to be justified for the same reasons given in the 2010 final rule. See 75 FR 54988 (September 9, 2010). We are, therefore, proposing this emissions limit for the kiln and clinker cooler and an initial and annual compliance test using Method 5 to demonstrate compliance. These issues affecting the existing source PM limit also apply to the new source PM limit. Based on this revised compliance regime, the new source floor would change from 0.01 lb/ton clinker produced, to 0.02 lb/ton clinker produced, based on a three run average from a Method 5 stack test. See Portland Cement Reconsideration TSD, section 8.3. The best performing kiln used to set the MACT floor for new sources in the 2010 rule was a cement kiln, not a CISWI kiln, so the same kiln was used for this analysis. The difference is that because a 3-run test would be used to determine compliance rather than a 30-day rolling average, the calculation of the 99th confidence UPL used m = 3 rather than 30, which results in a floor of 0.02 lb/ton clinker. The EPA is not proposing a beyond-the-floor standard for the reasons given at 75 FR 54988 (September 9, 2010). As indicated above, the EPA is further proposing to use PM CEMS technology for continuous parametric monitoring of the proposed PM standards. The EPA has developed requirements for continuously monitoring operating parameters in instances where compliance is based on non-continuous measurements, as would now be the case for PM. This implements section 114(a)(3) of the CAA which requires major sources to use enhanced monitoring for compliance certifications. The EPA's historic approach has been to require monitoring of a control device operating condition (e.g., electrical power, water flow rate, pH) the limit of which is based on a periodic compliance test with the compliance test method. The use of a continuous parametric monitoring system (CPMS) based on PM CEMS technology (PM CPMS) is a significant step closer to direct measurement of emissions in units of the emissions limit and an improvement over less direct monitoring of a process control device conditions. Specifically, this proposal recognizes the value of PM monitoring technology sensitive to changes in PM emissions concentrations and use of such a tool to assure continued good operation of PM control equipment. This approach avoids the PM CEMS calibration (i.e., PS 11 correlation) issues that can be exacerbated for Portland cement installations. PM CEMS technology can be effective in monitoring control device performance (see, e.g., 77 FR 9371 (February 16, 2012)) where the EPA established PM CPMS parametric operating limits for electricity generating units). As a result, this proposed rule would require the installation and operation of a PM CPMS for parametric monitoring associated with the proposed PM standard. The source owner would not have to meet PS 11 requirements but would have to prepare and submit for approval, if requested by a permitting authority, a site-specific monitoring plan to apply sound practices for installing, calibrating and operating the PM CPMS. Current PM CPMS have an operating principle based on in-stack or extractive light scatter, light scintillation or beta attenuation. The source owner or operator would need to examine the fuel and process conditions of his stack as well as the capabilities of these devices before selecting a particular CPMS technology. The reportable measurement output from the PM CPMS may be expressed as milliamps, stack concentration or other raw data signal. For the purposes of this proposed rule, the source owner would establish an operating limit based on the highest PM CPMS hourly value collected during the most recent PM compliance test (or other stack tests accepted as a legitimate basis for compliance, as explained below). The source would collect PM CPMS data continuously and calculate a 30 operating day rolling average PM CPMS output value from the hourly PM CPMS data collected during process operating hours and compare that average to the site specific operating limit. For these reasons (i.e., 30 days to mitigate the effects of measurement and emissions variability and using the highest hourly average from the stack testing), the EPA believes that use of the PM CPMS for parametric monitoring should not pose the same technical issues as those underlying the proposed decision to base compliance on PM CEMS measurements. We are proposing a number of consequences if the kiln PM monitoring parameter is exceeded. First, the source owner will have 48 hours to conduct an inspection of the control device and to take action to restore the controls if necessary and 45 days to conduct a new PM Method 5 compliance test to verify ongoing compliance with the PM limit. Within 60 days complete the emissions sampling, sample analyses and verification that the source is in compliance with the emissions limit in accordance with the test procedures in either section 60.64 or 63.1349(b)(1). Also, determine an operating limit based on the PM CPMS data collected during the performance test. Compare the recalculated operating limit with the existing operating limit and, as appropriate, adjust the numerical operating limit to reflect compliance performance. Adjustments may include applying the most recently established highest of the three test run hourly averages or combining the data collected over multiple performance tests to establish a more representative value. Apply the reverified or adjusted operating limit value from that time forward. Second, the EPA is proposing that this proposed rule limit the number of deviations of the site-specific CPMS limit leading to follow up performance tests in any 12-month process operating period and an excess of this number be considered to be a violation of the standard. This presumption could be rebutted by the source, but would require more than a Method 5 test to do so (e.g., results of physical inspections). This additional information is necessary since a Method 5 test could not be conducted following the discovery of deviations and would not necessarily represent conditions identical to those when the deviations occurred. The basis for this part of the proposal is that the site-specific CPMS limit could represent an emissions level higher than the proposed numerical emissions limit since the PM CPMS operating limit corresponds to the highest of the three runs collected during the Method 5 performance test. Second, the PM CPMS operating limit reflects a 30-day average that should represent an actual emissions level lower than the three test run numerical emissions limit since variability is mitigated over time. See 75 FR 54988 (September 9, 2010); 54975-76. Consequently, we believe that there should be few if any deviations from the 30-day parametric limit and there is a reasonable basis for presuming that deviations that lead to multiple performance tests to represent poor control device performance and to be a violation of the standard. Therefore, the EPA is proposing that PM CPMS deviations leading to more than four required performance tests in a 12-month process operating period to be presumed a violation of this standard, subject to the source's ability to rebut that presumption with information about process and control device operations in addition to the Method 5 performance test results. Finally, the EPA is proposing that the NSPS for PM established pursuant to section 111(bb) also be revised so that these limits are no longer CEMS-based and reflect the resulting different numerical values and averaging times. Although the NSPS for PM rests on a justification independent of the NESHAP PM standard (see PCA v. EPA, 665 F. 3d at 192-93), the technical issues associated with the use of PM CEMS in this industry are common to both standards and the proposed amendments, therefore, appear appropriate for the NSPS as well. The EPA believes that these proposed requirements represent Best Demonstrated Available Technology for new cement kilns given that the standards remain predicated on the performance of the best industry performers and the costs remain those already found to be reasonable. See id. at 191-92 discussing and upholding the EPA's NSPS for PM. E. Summary of Proposed Standards Resulting From Reconsideration The EPA is proposing the following revised MACT standards: Table 3—Proposed Existing and New Source Floors and Standards a Pollutant Existing source standard New source standard Mercury 55 lb/MM tons clinker 21 lb/MM tons clinker. THC 24 ppmvd 24 ppmvd. PM 0.07 lb/ton clinker (3-run test average) 0.02 lb/ton clinker (3-run test average). HCl 3 ppmvd 3 ppmvd. Organic HAP 12 ppmvd 12 ppmvd. a Standards for mercury and THC are based on a 30-day rolling average. The standard for PM is based on a three run test. If using a CEMS to determine compliance with the HCl standard, the floor is also a 30-day rolling average. Organic HAP standards are discussed in section H below. F. Standards for Fugitive Emissions From Clinker Storage Piles In the September 2010 rule, the agency established work practice requirements to reduce fugitive emissions from outdoor clinker storage piles. The agency had information that these storage piles emit HAP in the form of fugitive PM containing HAP metals, so that regulation of these sources was necessary. Because the emissions in question were fugitive dusts for which measurement was not feasible, the agency adopted work practices as the standard, specifically the work practice standards and opacity emissions limits contained in California's South Coast Air Quality Management District Rule 1156 as amended on March 6, 2009. Because there were only two plants which we could state definitively had open storage piles and both were complying with Rule 1156, we believed that the regulatory standards under Rule 1156 constituted the floor level of control. The current promulgated work practices consist of providing varying degrees of enclosures or barriers to prevent wind erosion of the storage piles. See generally 75 FR 54989 (September 9, 2010). In their reconsideration petition, the cement industry maintained that the EPA did not provide sufficient notice of the standards it might adopt for clinker storage piles. We agreed and granted reconsideration. See 76 FR 28325 (May 17, 2011). The D.C. Circuit stayed the standard pending the conclusion of the EPA's reconsideration. See 665 F. 3d at 189. Industry also noted, correctly, that more than two plants are potentially affected by clinker pile standards, so that the California rule is not necessarily a floor level of control. To evaluate which work practices are currently used in the industry, we requested data from the industry on currently used work practices. We also undertook a review of state permits to determine the level of controls to which open clinker piles are currently subject. Based on this information, the EPA is proposing to amend the work practices for clinker storage piles. 1. What is a clinker pile? Clinker storage is necessary to allow near continuous kiln operation and intermittent grinding and processing of the clinker. Clinker storage is also necessary in the event of unplanned or planned kiln shutdowns. Cement plants use silos, domes or other enclosure for clinker storage. Additional clinker storage may also be necessary to accommodate extended shutdown periods for kiln maintenance and/or market conditions. When the conventional enclosed storage is not adequate, clinker may be stored in outdoor piles. Unlike automated systems for drawing down clinker from enclosed silos, these temporary outdoor storage piles are drawn down using equipment such as front end loaders or other reclaiming equipment. Outdoor clinker storage may be temporary, lasting a few days or weeks and up to several months. There are also open clinker piles that have been in existence for years and are essentially permanent. 2. What are the proposed standards? We are proposing amended standards that will control HAP metal emissions from open clinker piles. Because the emissions are fugitive, we are proposing work practices instead of an emissions limit since it is “not feasible to prescribe or enforce an emission standard” for these emissions because, as fugitive emissions, they are not “emitted through a conveyance designed and constructed to emit or capture such pollutant”. See CAA section 112 (h)(2)(A). The work practices would apply to any open clinker piles regardless of the quantity of clinker or the length of time that the clinker pile is in existence. According to industry stakeholders, virtually all Title V permits oblige cement plant operators to “minimize” fugitive emissions including those from open clinker piles. See Portland Cement Reconsideration TSD, section 2, which is available in this rulemaking docket. Our examination of relevant permits indicates that some permits establish an opacity limit not to be exceeded in conjunction with materials management. Others contain a “no visible emissions” limitation at the fence line of the facility. Industry stakeholders state that to minimize fugitive emissions from open clinker piles, plants employ a number of practices, the most common being to use water sprays to form a concrete-like crust on the exposed surface of the clinker pile. Clinker has cement like properties and when exposed to water will hydrate and harden. The crust formed by this practice is very effective at reducing fugitive emissions as long as the pile is not disturbed. Another common practice is to cover clinker piles with tarps, which may be held down with tires, which effectively minimizes fugitive emissions. Some plants also use foam sprays on the exposed surface of the pile, forming a coating which reduces or prevents fugitive emissions. Based on our review of 88 state Title V permits, all but one permit required one or a combination of the following control measures to reduce fugitive emissions generally: Work practices, opacity or visible emission limits, prohibitions against open clinker piles and some type of general duty requirements to minimize fugitive dust emissions. Eight of the permits contained requirements specific to open or outdoor clinker piles. Eighteen permits contained standards that restricted emissions more generally from outdoor storage piles including opacity and visible emissions limits and general duty requirements to not produce PM or dust emissions at the property line. Seventy-seven permits contained facility-wide restrictions that applied to a variety of fugitive sources at the cement facilities (e.g. roads, storage, raw materials). In only one permit was it not clear that there were requirements to minimize fugitive dust emissions. With the exception of total enclosure of all open clinker piles, the EPA believes that the control measures in the permits are equally effective in reducing fugitive emissions. These measures are, therefore, consistent with section 112(d) controls and reflect a level of performance analogous to a MACT floor. See CAA section 112(h)(1) (in promulgating work practices, the EPA is to adopt standards “which in the Administrator's judgment [are] consistent with section (d) or (f) of this section.”) The option of full enclosures, somewhat analogous to a beyond-the-floor standard under section 112(d)(2), would be extremely costly with minimum associated emissions reductions incremental to the measures already undertaken (which already reduce most or all of the fugitive emissions from these piles). The EPA, therefore, is not proposing to mandate such a practice. Industry cost estimates for a full enclosure with a capacity of 50,000 tons of clinker range from $10-$25 million in capital cost and $400,000-$500,000 annual operating cost (See Portland Cement Association, Clinker Piles, September 7, 2011, available in the rulemaking docket). We also are not proposing opacity or visible emission standards, for several reasons. If work practices are properly implemented, we believe fugitive emissions, including visible emissions, from clinker piles will be effectively controlled. Such emission limits would also be redundant with work practice requirements. Moreover, in many cases, the temporary, short-term nature of clinker piles would make it impractical to implement an emissions monitoring program that would be more effective than the proposed work practices. We are proposing that one or more of the following control measures be used when adding clinker to a pile, during on-going clinker storage, and when reclaiming the clinker for processing, to minimize to the greatest extent practicable fugitive dust emissions from open clinker storage piles: Locating the source inside a partial enclosure (such as a three sided structure with tarp), installing and operating a water spray or fogging system, applying appropriate chemical dust suppression agents on the pile, use of a wind barrier or use of a tarp. The owner or operator must select, from the list provided, the control measure or combination of control measures that are most appropriate for the site conditions. We are allowing the owner or operator to select the most appropriate control measure or combination of measures for their situation. We are proposing that the owner or operator must include as part of their operations and maintenance plan (required in § 63.1347) the fugitive dust control measures that they will implement to control fugitive dust emissions from open clinker piles. These control measures would apply to the addition of clinker to the pile, on-going clinker storage and reclaiming the clinker for processing. We are proposing the same standards for new sources as existing sources. In the case of a clinker storage pile, there is no essential difference between `new' and `existing'. These piles generally reflect temporary storage situations, and are not analogous to building a one-time stationary structure where there are opportunities for newly-constructed entities that do not exist for existing entities. The EPA consequently is proposing the same standards for both. G. Affirmative Defense to Civil Penalties for Exceedances Occurring During Malfunctions In response to comments, the EPA added to the September 9, 2010, final rule an affirmative defense to civil penalties for exceedances of emissions limits that are caused by malfunctions. Various environmental advocacy groups, as well as the Portland Cement Association (PCA), indicated that there had been insufficient notice of this provision. The EPA agreed and granted reconsideration. See 76 FR 28325 (May 17, 2011). We are proposing to retain the affirmative defense on reconsideration. This provision seeks to balance a tension, inherent in many types of air regulation, to ensure adequate compliance while simultaneously recognizing that despite the most diligent of efforts, emission limits may be exceeded under circumstances beyond the control of the source. The EPA must establish emission standards that “limit the quantity, rate, or concentration of emissions of air pollutants on a continuous basis.” See 42 U.S.C. 7602(k) (defining “emission limitation and emission standard”). See generally Sierra Club v. EPA, 551 F.3d 1019, 1021 (D.C. Cir. 2008) Thus, the EPA is required to ensure that section 112 emissions limitations are continuous. The affirmative defense for malfunction events meets this requirement by ensuring that even where there is a malfunction, the emission limitation is still enforceable through injunctive relief. Although “continuous” limitations, on the one hand, are required, there is also case law indicating that in many situations it is appropriate for the EPA to account for the practical realities of control technology. For example, in Essex Chemical v. Ruckelshaus, 486 F.2d 427, 433 (D.C. Cir. 1973), the D.C. Circuit acknowledged that in setting standards under CAA section 111 “variant provisions” such as provisions allowing for upsets during startup, shutdown and equipment malfunction “appear necessary to preserve the reasonableness of the standards as a whole and that the record does not support the `never to be exceeded' standard currently in force.” See also, Portland Cement Association v. Ruckelshaus, 486 F.2d 375 (D.C. Cir. 1973). Though intervening case law such as Sierra Club v. EPA and the CAA 1977 amendments undermine the relevance of these cases today, they support the EPA's view that a system that incorporates some level of flexibility is reasonable. The affirmative defense simply provides for a defense to civil penalties for excess emissions that are proven to be beyond the control of the source. By incorporating an affirmative defense, the EPA has formalized its approach to upset events. In a Clean Water Act setting, the Ninth Circuit required this type of formalized approach when regulating “upsets beyond the control of the permit holder.” Marathon Oil Co. v. EPA, 564 F.2d 1253, 1272-73 (9th Cir. 1977); see also, Mont. Sulphur & Chem. Co. v. United States EPA, 2012 U.S. App. LEXIS 1056 (Jan 19, 2012) (rejecting industry argument that reliance on the affirmative defense was not adequate). But see, Weyerhaeuser Co. v. Costle, 590 F.2d 1011, 1057-58 (D.C. Cir. 1978) (holding that an informal approach is adequate). The affirmative defense provisions give the EPA the flexibility to both ensure that its emission limitations are “continuous” as required by 42 U.S.C. § 7602(k), and account for unplanned upsets and thus support the reasonableness of the standard as a whole. Petitions filed by environmental advocacy groups question the EPA's authority to promulgate the affirmative defense arguing, among other things, that the affirmative defense is inconsistent with the provisions of CAA sections 113(e) and 304(b) governing penalty assessment and citizen suits, respectively. The EPA's view is that the affirmative defense is not inconsistent with CAA section 113(e) or 304. Section 304 gives district courts' jurisdiction “to apply appropriate civil penalties.” Section 113(e)(1) identifies the factors that the Administrator or a court shall take into consideration in determining the amount of a penalty to be assessed, once it has been determined that a penalty is appropriate. The affirmative defense regulatory provision is not relevant to the amount of any penalty to be assessed. If a court determines that the affirmative defense elements have been established, then a penalty is not appropriate and penalty assessment pursuant to the section 113(e)(1) factors does not occur. In exercising its authority under section 112 to establish emission standards (at a level that meets the stringency requirements of section 112), the EPA necessarily defines conduct that constitutes a violation. The EPA view is that the affirmative defense is part of the emission standard and defines two categories of violation. If there is a violation of the emission standard and the source demonstrates that all the elements of the affirmative defense are met, only injunctive relief is available. All other violations of the emission standard are subject to injunctive relief and penalties. A citizen suit claim under section 304 allows citizens to commence a civil action against any person alleged to be in violation of “an emission standard or limitation under this chapter.” The CAA, however, allows the EPA to establish such “enforceable emission limitations.” Thus, the citizen suit provision clearly contemplates enforcement of the standards that are defined by the EPA. As a result, where the EPA defines its emissions limitations and enforcement measures to allow a source the opportunity to prove its entitlement to a lesser degree of violation (not subject to penalties) in narrow, specified circumstances, as the EPA did here, penalties are not “appropriate” under section 304. The EPA solicits comments on this issue of the EPA's authority to promulgate an affirmative defense. The EPA's view is that an affirmative defense to civil penalties for exceedances of applicable emission standards during periods of malfunction appropriately balances competing concerns. On the one hand, citizen enforcers are concerned about additional complications in their enforcement actions. On the other hand, industrial sources are concerned about being penalized for violations caused by malfunctions that they could not have prevented and were otherwise appropriately handled (as reflected in the affirmative defense criteria). The EPA has used its section 301(a)(1) authority to issue regulations necessary to carry out the Act in a manner that appropriately balances these competing concerns. However, the EPA also solicits comment on alternatives to, or variations on, the affirmative defense provisions promulgated in the 2010 final rule. In its petition for reconsideration, the PCA expressed support for the affirmative defense, but maintains that “the affirmative defense process that EPA codified in the final rules is cumbersome and will be exceedingly difficult for facilities to employ.” The EPA is soliciting comment on the terms and condition of the affirmative defense. In recent rules promulgated under section 112 and 129, the EPA has revised certain terms and conditions of the affirmative defense in response to concerns raised by various commenters. The EPA is proposing to adopt those same revisions in this proposed rule. The EPA is proposing to revise the affirmative defense language to delete “short” from section 63.1344(a)(1)(i), because other criteria in the affirmative defense require that the source assure that the duration of the excess emissions “were minimized to the maximum extent practicable.” The EPA is also proposing to delete the term “severe” in the phrase “severe personal injury” in 63.1344(a)(4) because we do not think it is appropriate to make the affirmative defense available only when bypass was unavoidable to prevent severe personal injury. In addition, the EPA is proposing to revise section 63.1344(a)(8) to add “consistent with good air pollution control practice for minimizing emissions.” The EPA is also proposing to revise the language of 63.1344(a)(9) to clarify that the purpose of the root cause analysis is to determine, correct and eliminate the primary cause of the malfunction. The root cause analysis itself does not necessarily require that the cause be determined, corrected or eliminated. However, in most cases, the EPA believes that a properly conducted root cause analysis will have such results. Further, the EPA is proposing to revise 63.1344(b) to state that “[t]he owner or operator seeking to assert an affirmative defense shall submit a written report to the Administrator in a semiannual report with all necessary supporting documentation, that it has met the requirements set forth in section 63.1354(c) of this subpart.” This report must be included in the first semiannual report, required by section 63.1354(b)(9), after the initial occurrence of the violation of the relevant standard. If the semiannual report is due less than 45 days after the initial occurrence of the violation, the affirmative defense report may be included in the second semiannual report due after the initial occurrence of the violation of the relevant standard. See proposed regulatory text for other proposed minor wording changes to improve clarity. H. Continuously Monitored Parameters for Alternative Organic HAP Standard (With THC Monitoring Parameter) In the September 2010 final rule, the EPA promulgated an alternative standard for non-dioxin organic HAP, based on measuring the organic HAP itself rather than the THC surrogate. Section 63.1343(b)(1) provides two options for meeting a standard for organic HAP. One is to meet a THC standard of 24 ppmvd; the other is to meet a limit of 9 ppmvd of total organic HAP. This equivalent alternative standard is intended to provide additional flexibility in determining compliance, and it would be appropriate for those 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. The specific organic compounds that are to be measured to determine compliance with the equivalent alternative standard are benzene, toluene, styrene, xylene (ortho-, meta-, and para-), acetaldehyde, formaldehyde and naphthalene. Compliance with the equivalent alternative standard under the September 2010 standard will be determined through organic HAP emissions testing using EPA Method 18 or 320, as appropriate for the compound of interest. The 2010 rule further requires that each source complying with the alternative standard establish a site-specific THC limit to be met continuously. The site-specific THC limit will be measured as a 30 day rolling average, with an annual compliance test requirement. It would be correlated with the organic HAP limit and is therefore not tied to the THC standard of 24 ppmvd. We granted reconsideration on the level of this site-specific THC limit used as a continuously monitored parameter for those sources selecting the alternative HAP compliance method. See 76 FR 28318 (May 17, 2011). Since THC includes compounds that are not considered to be hazardous, either of the two standards are considered to be reasonable. While the September 2010 final rule required an organic HAP limit of 9 ppmvd, a recent review of the method detection limits used to measure organic HAP revealed that three times the representative method detection level (3*RMDL) is actually 12 ppmvd, therefore, we propose to revise the alternative organic HAP limit to 12 ppmvd. As discussed in the final rule, the expected measurement imprecision for an emissions value at or near the method detection level is about 40 to 50 percent and decreases to a consistent 10 to 15 percent for values that are three times the method detection level. See 75 FR 54984 (September 9, 2010); see also section D above. Thus, measured values less than three times the representative method detection level are highly uncertain and therefore not reasonable for compliance determinations. The 3*RMDL of 12 ppmvd was determined as follows: we determined method detection capabilities for Method 320 and Method 18 as appropriate for the various compounds (e.g., Method 320 for aldehydes, Method 18 for aromatic hydrocarbons (arenes)). This approach is consistent with procedures practiced by the better performing testing companies and laboratories using sensitive analytical procedures. We determined for each of the organic HAP the expected method detection level for the respective method based on internal experience and method capabilities reported by testing companies. With these reported values, we identified the resulting mean of the method detection levels, adjusted them for dilution and moisture, summed them, and then multiplied the sum by three to determine the representative detection level (RDL). The resulting RDL value was found to be 11.2 ppmvd @ 7 percent oxygen (O 2 ), dry. This value is greater than the final 9 ppmvd @ 7 percent O 2 , dry, in the final rule. We are, therefore, proposing to adjust the total organic HAP limit to 12 ppmvd @ 7 percent O 2 , dry (rounded up from the 11.2 ppm RDL). At this level, we believe that currently available emissions testing procedures and technologies can be used to provide measurements of sufficient certainty for sources to demonstrate compliance. A detailed discussion of the use of the RDL to arrive at the proposed organic HAP limit is found in the Portland Cement Reconsideration TSD, section 3, which can be found in the docket for this rulemaking. A consequence of this analysis is that the accuracy of the analytic methods for organic HAP appear to be insufficient to allow sources to scale up their site-specific THC limit based on the degree to which the measured organic HAP levels were below the organic HAP limit—the organic HAP limit, even as proposed to be revised, is at the reliable limit of detection as just explained. Therefore, this proposed rule retains the provision whereby the site-specific THC operating parameter is established at the same time the performance test is conducted for organic HAP. If the site-specific THC operating parameter is exceeded, then the kiln would have to be retested to determine compliance with the organic HAP limit. This proposed rule would further require that the tests for organic HAP and THC be repeated annually to establish a new annual site-specific THC parameter reflecting the organic HAP level. We also are proposing, similar to the PM compliance test procedure, that the highest 1-hour average THC concentration measured during the 3-hour organic HAP test, be used as the site-specific THC parameter, and are allowing facilities to extend the testing time (or number of tests) if they believe extended testing is required to adequately capture THC variability over time. The EPA specifically solicits comment on the changes on the organic HAP limit. In addition, we solicit comment on if it would it be appropriate to allow sources to scale up their site-specific THC limit based on the degree to which the measured organic HAP levels are below the organic HAP limit. I. Allowing Sources With Dry Caustic Scrubbers To Comply With HCl Standard Using Performance Tests To demonstrate compliance with the HCl emissions limit, the September 2010 final rule allows sources equipped with wet scrubbers to comply with the HCl standard by means of periodic performance tests rather than with continuous monitoring of HCl with a CEMS (see § 63.1349(b)(6)). We reasoned that a source that uses a limestone wet scrubber for HCl control will have minimal HCl emissions even if kiln inputs change because limestone wet scrubbers are more efficient in removing HCl than they are required to be, to meet the standard. Sources electing to comply by means of stack tests must establish continuously monitored parameters including liquid flow rate, pressure and pH. Sources using a limestone wet scrubber are required to perform an initial compliance test using Method 321 in Appendix A to 40 CFR part 63 and to test every 30 months thereafter. In their petition, industry stakeholders indicated that this compliance option should not be limited to wet scrubber equipped units, but should also be available for units equipped with caustic scrubbers, in part because some sources will be equipped with dry scrubbers (due to water shortages) and should have the same operating flexibilities as wet scrubber equipped kilns. A recent review of data from a vendor of acid gas controls using a standard hydrated lime and a high performance hydrated lime at a U.S. cement manufacturing plant, revealed that HCl removal from dry scrubbers on kilns ranged from 90 to 95 percent HCl removal, depending on lime injection rates (Lhoist North America, Cement Industry Experience, DSI for Acid Gas Control, October 5, 2011). The results also showed the plant could meet the 3 ppm HCl limit. The EPA also evaluated HCl removal efficiency using dry sprayer absorber with a fabric filter as part of the electric utility generating MACT rulemaking. Removal efficiencies ranged from 95 percent to nearly 100 percent with an average of about 99.8 percent (Hutson to Nizich, HCl control using SDA/FF, November 29, 2011). In addition, information from the National Lime Association ( http://www.lime.org/uses_of_lime/environmental/flue_gas.asp ) and the Institute for Clean Air Companies ( http://www.icac.com/i4a/pages/index.cfm?pageid=3401 ) report HCl emissions reductions using dry lime injection technology of 95 to 99 percent from coal-fired boilers in the electric utility industry, from municipal waste-to-energy facilities and from other industries. In the secondary aluminum industry, reductions in HCl emissions greater than 99 percent have been achieved (National Lime Association, Flue Gas Desulfurization, http://www.lime.org/uses_of_lime/environmental/flue_gas.asp ). Given these high reported removal efficiencies, we propose to extend the same option provided to kilns equipped with wet scrubbers to dry scrubber-equipped kilns. Thus, kilns with either type of scrubber could demonstrate compliance with the HCl limit by means of an initial and periodic stack test rather than with continuous compliance monitoring with a CEMS. In order to assure that the dry lime injection equipment is operated effectively between tests, the proposed amendment would require that the lime injection rate used during the performance test demonstrating compliance with the HCl limit be recorded and then continuously monitored between performance tests to show that the injection rate remains at or above the rate used during the performance test. We are also proposing an additional alternative for all kilns equipped with a dry or wet scrubber (and, under this proposal, could therefore do periodic HCl performance testing and parametric monitoring). Where either wet or dry scrubbers are used, we are proposing that an owner or operator would have the option of using SO 2 monitoring as a continuously monitored parameter for purposes of compliance monitoring. Because HCl is a water-soluble compound and because it has a large acid dissociation constant (i.e., HCl is a strong acid), it will be more rapidly and readily removed than SO 2 from a gas stream treated with either caustic sorbents (e.g., lime, limestone) or plain water. We acknowledge that at proposal (see 74 FR 21154, May 6, 2009) we rejected setting a standard (as opposed to a continuously monitored parameter) that used SO 2 as a surrogate for HCl because we had no data that demonstrated a direct link between HCl emissions and SO 2 emissions. However, pilot-scale tests by the EPA at its Multi-pollutant Control Research Facility support the use of the more easily measured SO 2 as a surrogate for HCl where either wet or dry scrubbers are used. See Docket item EPA-HQ-OAR-2009-0234-3893. Further, we are aware that there are existing kilns equipped with SO 2 CEMS and that this monitoring technology is less expensive and more mature than HCl CEMS. Thus, we are proposing that SO 2 is an indicator for HCl compliance, and that monitoring the emissions of SO 2 will provide a reliable indication of HCl removal, making SO 2 monitoring an appropriate parameter for monitoring continuing compliance. Owners or operators of kilns equipped with dry or wet scrubbers that choose to use SO 2 monitoring would need to conduct an initial performance test for HCl and establish the SO 2 operating limit equal to the highest 1 hour average recorded during the HCl performance test, so that there is an indication of proper operation of the HCl control device. The owner or operator of a kiln controlled using either a dry or wet scrubber that chooses to monitor SO 2 would not be required to also establish continuously monitored parameters reflecting the performance test results, such as lime injection rate for a dry scrubber and liquid flow rate, pressure and pH for a wet scrubber. Deviation from any established parameter level or established SO 2 operating level would trigger a requirement to retest for HCl in order to verify compliance with the HCl limits and to verify or re-establish the parameter levels. At a minimum, a repeat performance test to confirm compliance with the HCl emissions limit and to reset the SO 2 limit and monitoring parameters is required every 5 years. We are requesting comment on the efficacy of continuously monitoring SO 2 as a continuously monitored parameter in lieu of continuously monitoring HCl control device parameters, and also solicit comment on testing every 30 months for HCl for purposes of monitoring compliance with the HCl emissions limit. J. Alternative PM Limit Some kilns combine kiln exhaust gas with exhaust gas from other unit operations, such as the clinker cooler, as an energy saving practice. The September 2010 final rule sought to accommodate commingled flows from the kiln and clinker cooler by providing a site specific PM limit. See section 63.1343(b)(2). In its reconsideration petition, the PCA pointed out, however, that other flows besides the exhaust gas flow from the clinker cooler can be commingled as well. The petitioner provided the example of coal mill exhaust and exhaust from an alkali by-pass as instances of additional flows that can be commingled with the exhaust gas flow from the kiln. The petitioner observed that without an allowance for these additional flows, the site specific PM limit is stricter than the EPA intended (since the PM concentration will be divided by a lower number in the implementing equation), and penalizes the energy-saving practice of commingling these flows. The agency agreed with the petitioner that the alternative PM equations for existing and new sources contained in the final rule do not adequately account for commingled exhaust gas flows from sources other than the clinker cooler, and granted reconsideration for this reason. See 76 FR 28325 (May 17, 2011). We believe that although the form of the equation is correct, the equation is not written to accommodate sources other than exhaust gases from the clinker cooler. We are proposing to revise the equation so that it includes exhaust gas flows for all potential sources that would potentially be combined, including exhausts from the kiln, the alkali bypass, the coal mill, and the clinker cooler, for an existing kiln, the EPA is proposing the following equation: PM alt = 0.0060 × 1.65 × (Q k + Q c + Q ab + Q cm )/(7000) Where: PM alt = The alternative PM emission limit for commingled sources. 0.006 = The PM exhaust concentration (gr/dscf) equivalent to 0.07 lb per ton clinker where clinker cooler and kiln exhaust gas are not combined. 12 12 Note that this figure would change correspondingly if the EPA were to amend the existing source PM standard. The same is true of the PM term in the new source equation. 1.65 = The conversion factor of lb feed per lb clinker. Q k = The exhaust flow of the kiln (dscf/ton raw feed). Q c = The exhaust flow of the clinker cooler (dscf/ton raw feed). Q ab = The exhaust flow of the alkali bypass (dscf/ton raw feed). Q cm = The exhaust flow of the coal mill (dscf/ton raw feed). 7000 = The conversion factor for grains (gr) per lb. If exhaust gases for any of the sources contained in the equation are not commingled and are exhausted through a separate stack, their value in the equation would be zero. The alternative PM equation for new sources is identical to the existing source equation except the PM exhaust concentration used in the equation is 0.002 grains per dry standard cubic foot, which is equivalent to the new source PM limit of 0.02 lb/ton clinker. K. Standards During Startup and Shutdown In the final NESHAP, the EPA established separate standards for startup and shutdown which differ from the main standards. These standards require kilns to meet numerical limits for each pollutant regulated by the rule, each standard to be measured using a CEMS over an accumulative 7-day rolling average. 75 FR 54991 (September 9, 2010). Industry petitioned the EPA to reconsider these standards claiming lack of notice, but the EPA denied these petitions because the agency had already provided ample opportunity for comment which petitioners had used. See 76 FR 28323 (May 17, 2011). The D.C. Circuit dismissed all challenges to these startup and shutdown provisions (see 665 F 3d at 189). The EPA did grant reconsideration on several technical issues related to startup and shutdown—certain aspects of CEM-based monitoring of mercury and PM during startup and shutdown—issues which would be moot if the EPA adopts the approach proposed below—and having an HCl limit of zero for kilns not equipped with CEMS (see 76 FR 28325 (May 17, 2011)). The EPA is proposing to retain the startup and shutdown standards for mercury and THC, to amend the startup and shutdown standards for PM to be consistent with the proposed numeric levels in this proposal, and to amend the level of the startup and shutdown standard for HCl to be 3 ppm in all circumstances. The EPA is further proposing to clarify that startup begins when the kiln's induced fan is turned on and continues until continuous raw material feed is introduced into the kiln. Shutdown begins when feed to the kiln is halted. Thus, during startup and shutdown, as defined, a kiln would not be firing coal or coke and would not be introducing feed material into the kiln continuously. HAP emissions from cement kilns are attributable almost entirely to one or the other of these feeds, with raw materials contributing the great preponderance. In addition, kilns burn fuels during startup and shutdown which are cleaner than coal and coke (natural gas is used for the most of the startup). Thus, HAP emissions during startup and shutdown necessarily should be far less than the numerical limits in the standards since the kiln will not be introducing raw materials, and will be burning fuels which are cleaner than its normal fuels. Accordingly, the EPA is further proposing to change the means of monitoring for compliance with the startup and shutdown standards. Rather than require monitoring by a CEM or by stack testing, the EPA is proposing that a source keep records of the volumes of fuels introduced into the kiln during startup and shutdown to verify that raw materials are not introduced into the kiln, although, by definition, if raw materials are introduced continuously into the kiln, the kiln is not operating in startup and shutdown and the monitoring requirements of the main standards would therefore apply. Kiln owners and operators would then make conservative assumptions as to the combustion efficiency of the kiln so as to reasonably estimate destruction of organics, and include mass balance calculations showing that the startup/shutdown standards would not be exceeded. These proposed recordkeeping requirements would serve as the basis for compliance monitoring. The EPA believes that these proposed recordkeeping requirements are both sufficient to yield reliable information for the startup and shutdown periods, and to establish a source's compliance or non-compliance with the startup and shutdown standards. The EPA also believes that this proposed requirement would satisfy the requirements of 40 CFR section 70.6(c)(1) which requires that Title V permits shall contain “monitoring * * * requirements sufficient to assure compliance with the terms and conditions of the permit.” The EPA is further proposing that the standard for HCl during startup and shutdown be 3 ppmvd under all circumstances, and thus is proposing to eliminate the current provision that the startup and shutdown standard be zero for kilns measuring compliance by means other than a CEM. As shown in the petitions for reconsideration, HCl can be formed even when normal fuels and raw materials are not being introduced into the kiln (for example, from residual chlorides in the kiln refractory). See PCA Petition for Reconsideration Exh. 1. Consequently, the promulgated limit of zero is technically inappropriate, and the EPA is proposing to amend it to 3 ppmvd, the same standard which applies in all other operating modes. Monitoring during startup and shutdown would be accomplished by recordkeeping, as explained above. The EPA also solicits comment on whether the numeric standards during startup and shutdown should be amended to provide work practices, rather than numeric standards. Work practices could require operation of emission control devices during startup and shutdown, minimizing the time periods of startup/shutdown, and following manufacturer's best practices. We rejected work practices for startup and shutdown periods in the 2010 final rule because the commenters requesting such standard failed to demonstrate why it is “not feasible * * * to prescribe or enforce an emission standard” for mercury, THC, PM and HCl during startup and shutdown at cement kilns, within the meaning of section 112(h) of the Act. See NESHAP from the Portland Cement Manufacturing Industry Response to Comments Received on Proposed Rule Published on May 6, 2009, 74 FR 21135, August 6, 2010 at p. 184. L. Coal Mills Cement kilns burn coal as their main fuel, and mill the coal before firing it. From the standpoint of air emissions, these coal mills are sometimes physically distinct from the cement kiln, generating emissions solely attributable to the coal mill and emitting exhaust through a dedicated stack. However, some kilns are configured so that coal mill emissions are commingled with kiln exhaust and the emissions are discharged through the main kiln stack. Finally, there are some configurations whereby kiln emissions are routed to the coal mill and discharged through the coal mill stack. This part of the preamble discusses the regulatory treatment of these different scenarios. First, the EPA has promulgated new source performance standards (40 CFR part 60 subpart Y) for coal mills. See 74 FR 51952 (October 8, 2009). These standards apply to coal mills, including coal mills at cement manufacturing facilities, which emit through a dedicated stack. Subpart Y standards do not apply to coal mills at cement facilities whose only heat source is kiln exhaust. See section 60.251(j) (definition of indirect thermal dryer). This leaves ambiguous, or partially ambiguous, the regulatory treatment of the second and third situations mentioned above: A kiln whose coal emissions are discharged through the main kiln stack, and the coal mill which receives some exhaust from the cement kiln so that some portion of the coal mill exhaust can reflect cement kiln emissions. Because we did not address these issues in the 2010 final NESHAP for Portland cement kilns, we granted reconsideration in order to do so. See 76 FR 28326 (May 17, 2011). A cement kiln which commingles emissions from its coal mill with all other emissions and discharges through kiln emission points would have to meet all of the NESHAP. In the case of PM, the additional flow from the coal mill would be accounted for in the equation used to determine PM contributions from commingled flows. See section K above. In the case of a coal mill which receives and discharges some of the cement kiln exhaust, the regulatory concern is that this re-routing of kiln exhaust not result in uncontrolled HAP emissions. Our basic principle for this situation could be that the kiln demonstrate that it is meeting all of the NESHAP standards for pollutants not regulated under the subpart Y coal mill standard, that is mercury, THC and HCl. Because the subpart Y standards contain a PM standard predicated on use of fabric filter control technology, we do not believe it necessary to account for diverted PM emissions. We are soliciting comment on the following compliance mechanism for the mercury, THC and HCl standards in this situation: The sum of the mercury, THC and HCl in the kiln exhaust diverted to the coal mill, and the kiln exhaust exhausted in the main kiln stack, must not exceed the subpart LLL NESHAP emission limits for each respective HAP or HAP surrogate. Under this approach, the rule could contain requirements to document the contribution of the emissions diverted to the coal mill. With respect to THC and HCl, because coal may be a source of these emissions, we are soliciting comment on a requirement that performance tests for THC and HCl be performed upstream of the coal mill. For mercury, we are soliciting comment on a requirement that tests be required downstream to account for any mercury removal in the coal mill air pollution control device (APCD), and to avoid double counting emissions of mercury from mercury that becomes re-entrained in the coal, which is then burned by the cement kiln (which emissions are otherwise accounted for in the NESHAP). We note further that an analogous situation is when a cement kiln has an alkali bypass which receives and exhausts emissions from the kiln. We are proposing that these emissions be subject to controls reflecting the same principle—the total emissions of the kiln and alkali bypass must meet the subpart LLL NESHAP. We are also proposing to use the same monitoring procedures to document compliance. The one (slight) exception is for PM. Because there is no independent PM standard for an alkali bypass (unlike the situation for coal mills, where subpart Y regulates PM emissions), the summed PM emissions from the kiln and alkali bypass would have to be equal to or less than the PM limit in the subpart LLL NESHAP. Tests for PM from the alkali bypass would be downstream of the alkali bypass APCD to account for those emission reductions. Though we are not proposing the coal mill requirements in this action, we have placed the appropriate regulatory text in the proposed rule language to allow comment on actual rule language. We expand on these monitoring provisions below. 1. Mercury. Although mercury from the main stack is monitored using a CEMS, there is no need for such monitoring for the gas streams from the coal mill. The gas stream to the coal mill is small in comparison to the kiln exhaust, operation of the coal mill is intermittent, and the cost of requiring additional CEMS for coal mills would be overly burdensome. Instead, the performance tests for mercury could be conducted at such a coal mill once per year, and, as explained above, that the tests be conducted downstream of the coal mill. Performance tests for mercury could be conducted using either Methods 29 or 30B in Appendix A-8 to 40 CFR Part 60. These performance tests could be required annually until the tested mercury levels are below the method detection limits for two consecutive years, after which tests may be conducted every 30 months. If test results at any time exceed the method detection limit, annual performance testing could again be required until mercury levels are below the method detection limit for two consecutive years. The results of the performance test could then be summed with the emissions from the kiln stack to determine compliance with the mercury emissions limit. Since kiln stack emissions are measured continuously with a CEMS, the coal gas emissions could be normalized on both a CEMS and production basis (lb/MM ton clinker) in order to be summed with the kiln stack emissions. To do so, the flow rate to the coal mill could be continuously monitored. Using the results of the annual performance test and the continuous flow rate from the coal mill, the owner or operator could develop a mercury hourly mass emission rate for the coal mill. Hourly mercury emissions from the coal mill could be summed with the mercury emissions from the kiln to determine continuous compliance as follows: ((Qab×Cab) + (Qcm×Ccm) + (Qks×Cks))/P ≤ MACT Limit Where: Qab = Alkali bypass flow rate (volume/hr) Cab = Alkali bypass concentration (lb/dscf) Qcm = Coal mill flow rate (volume/hr) Ccm = Coal mill concentration (lb/dscf) Qks = Kiln stack flow rate (volume/hr) Cks = Kiln stack concentration (lb/dscf) P = Kiln production rate (million tons clinker/hr) MACT Limit = Limit for mercury (55 lb mercury/MM tons clinker) This equation requires all values to be at or corrected to 7 percent O 2 . Thus, if the normalized test results at the coal mill control device outlet shows mercury emissions of 10 lb/MM tons clinker, emissions from the kiln should be less than 45 lb/MM tons of clinker to be in compliance with the proposed kiln mercury emissions limit. See section 63.1350(k)(5). For kilns also equipped with an alkali bypass, the same procedure as that for the coal mill would apply. Where a portion of kiln gases are diverted to a coal mill and to an alkali bypass, emissions from the coal mill and alkali bypass would be tested, normalized and summed and with the mercury emissions from the kiln to determine compliance with the emissions limit. 2. THC and HCl. Because THC and HCl are concentration-based limits, the compliance demonstration could differ in certain details from the procedure described above for the production based limits for mercury. Kiln stack emission limits (to be continuously monitored) could be calculated taking into consideration the volumetric exhaust gas flow rates and concentrations of all applicable effluent streams (kiln stack, coal mill, and alkali bypass) for the kiln unit as follows: ep18jy12.000 Where: Qab = Alkali bypass flow rate (volume/hr) Cab = Alkali bypass concentration (ppmvd) Qcm = Coal mill flow rate (volume/hr) Ccm = Coal mill concentration (ppmvd)e Qks = Kiln stack flow rate (volume/hr) Cks = Kiln stack concentration (ppmvd) MACT Limit = Limit for THC or HCl (ppmvd) This equation requires all values to be at or corrected to 7 percent O 2 . 13 13 The proposed approach is conceptually similar to that for PM from multiple sources discussed in K. above—an equation which accounts for the flow-weighted concentration of PM from all sources. In order to determine the flow rates and concentrations of THC and HCl in the coal mill and alkali bypass streams, the source could test annually using the appropriate test method and could monitor the flow rate of the kiln stack with CMS. For HCl, the performance test could be performed using Method 321 in Appendix A to 40 CFR Part 63. For measurement of THC, Method 25A in Appendix A-7 to 40 CFR Part 60 could be required. With these data, the concentration of THC and HCl that must be monitored in the CEMS in order to demonstrate compliance with the kiln MACT limit under this proposal can be calculated by solving for Cks (kiln stack concentration) from the equation above, as shown: EP18JY12.001 This equation is based on the following: • The total allowable mass emissions of THC and HCl for the kiln unit can be determined with the sum of all flow rates (coal mill, alkali bypass and kiln stack) and the applicable NESHAP limit (THC or HCl) concentration. This yields the total allowable mass emissions per unit of time for the kiln unit according to the MACT limits and the site specific flow rates for the coal mill, alkali bypass and kiln stack. • By testing the coal mill and alkali bypass streams for concentration and flow rate, the actual mass of THC and HCl emitted per unit of time can be determined. • Subtracting the actual mass emissions of THC and HCl leaving the coal mill and alkali by pass from the total allowable mass emissions for the kiln unit determines the remainder of allowable mass emissions that can be emitted through the kiln stack. • With knowledge of the flow rate at the kiln stack (measured by CMS) and the allowable mass emissions (i.e. remainder) that can be emitted through the kiln stack, a site specific concentration can be determined. The equation above provides a simplified approach to determining this value. The following example indicates how compliance could be demonstrated. In this example, we assume a kiln stack, coal mill and alkali bypass with the following volumetric flow rates and THC concentrations: Effluent stream Flow THC concentration Notes MACT LIMIT rate (ppmvd) (ppmvd) (dscm/hr) (@7% O 2 ) (@7% O 2 ) Alkali [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2012-16166. Public record. Not legal advice.