[6560
- 50
- P]

ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 60 and 63 [ EPA-HQ-OAR- 2007 - 0877 ; FRL - ] RIN 2060 -AO42 Standards of Performance for Portland Cement Plants AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: The EPA is proposing amendments to the current Standards of Performance for Portland Cement Plants. The proposed amendments include revisions to the emission limits for affected facilities which commence construction, modification, or reconstruction aft er [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER]. The proposed amendments also include additional testing and monitoring requirements for affected

sources. DATES: Comments must be received on or before [INSERT DATE 60 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER] . If any one contacts EPA by [INSERT DATE 10 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER] requesting to speak at a public hearing, EPA will hold a public hearing on [INSERT DATE 15 DAYS AFTER PUBLICATION OF THIS PROPOSE D RULE IN THE FEDERAL REGISTER]. Under the Paperwork Reduction Act, comments on the information collection provisions must be received by the Office2

of Management and Budget (OMB) on or before [INSERT DATE 30 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. ADDRESSES: Submit your comments, identified by Docket ID No. EPA- HQ - OAR- 2007
- 0877, by one of the following methods:

• http://www.regulations.gov : Follow the on
- line instructions for submitting comments.

• E -mail: a - and
- r - docket@epa.gov .

• Fax: (202) 566
- 1741.

• Mail: U.S. Postal Service, send comments to: EPA Docket Center (6102T), Standards of Performance (NSPS) for Portland Cement Plants Docket, Docket ID No. EPA
HQ - OAR- 2007
- 0877, 1200 Pennsylvania Ave., NW, Washington, DC 20460. Please inclu de a total of two copies. In addition, please mail a copy of your comments on the information collection provisions to the Office of Information and Regulatory Affairs, Office of Management and Budget (OMB), Attn : Desk Officer for EPA, 725 17th St., NW, Washington, DC 20503.

• Hand Delivery: In person or by courier, deliver comments to: EPA Docket Center (6102T), Standards of Performance (NSPS) for Portland Cement Plants Docket, Docket ID No. EPA
- HQ - OAR- 2007
- 0877, EPA West, Room 3334, 1301 Constitution Avenue, NW, Washington, DC3 20004. Such deliveries are only accepted during the Docket’s normal hours of operation, and special arrangements should be made for deliveries of boxed information. Please include a total of two copies. Instructions : Direct your comments to Docket ID No. EPA
HQ - OAR- 2007
- 0877. EPA’s policy is that all comments received will be included in the public docket without change and may be made available online at www.regulations.gov , including any personal information provided, unless t he comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit information that you consider to be CBI or otherwise protected through www.regulations.gov or e -mail. The www.regulations.gov website is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an e
-mail comment directly to EPA without going through www.regulations.gov , your e -mail address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD
- ROM you submit. If EPA cannot read your comment due to technical difficulties and4

cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. Docket : All documents in the docket are listed in the www.regulations.gov index. Al though listed in the index, some information is not publicly available, e.g., CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, will be publicly available only in hard copy. Publicly available docket materials are available either electronically in www.regulations.gov or in hard copy at the EPA Docket Center, Standards of Performance (NSPS) for Portland Cement Plants Docket, EPA West, Room 3334, 1301 Constitution Ave., NW, Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566
- 1744, and the telephone number for the Docket Center is (202) 566
- 1742. FOR FURTHER INFORMATION CONTACT: Mr. Keith Barnett, Office of Air Quality Planning and Standards, Sector Policies and Programs Division, Metals and Minerals Group (D243
- 02), Environmental Protection Agency, Research Triangle Park, NC 27711, telephone5

number: (919) 541
- 5605; fax number: (919) 541
- 5450; e
-mail address: barnett.keith@epa.gov . SUPPLEMENTARY INFORMATION: The information presented in this preamble is organized as follows: I. General Information A. Does this action apply to me? B. What should I consider as I prepare my comments to EPA? C. Where can I get a copy of this document? D. When would a public hearing occur? E. How is this document organized? II. Background Information on Subpart F A. What is the statutory authority for the proposed amendments to subpart F? B. What are the current Portland C ement plant (PCP) NSPS? III. Summary of the Proposed Amendments to Subpart F IV. Rationale for the Proposed Amendments to Subpart F A. How is EPA proposing to change the emission limits for future affected facilities? B . How is EPA proposing to amend the testing requirements? C . How is EPA proposing to amend the monitoring requirements? D. Why are other emission limits in the NSPS not being revised? E. What other changes are being proposed? F. What is EPA’s sector
- based approach and how is it relevant to this rulemaking? G. How is EPA addressing greenhouse gas emissions from the portland cement industry? V. Summary of Cost, Environmental, Energy, and Economic Impacts of the Proposed Amendments to Subpart F A. What are the air quality impacts? B. What are the water quality impacts? C. What are the solid waste impacts? D. What are the secondary impacts? E. What are the energy impacts? F. What are the cost impacts? G. What are the economic impacts? VI. Statutory and Executive Order Reviews A. Executive Order 12866: Regulatory Planning and Review B. Paperwork Reduction Act C. Regulatory Flexibility Act D. Unfunded Mandates Reform Act6

E. Executive Order 13132: Federalism F. Executive Order 13175: Consultation and Coordination with Indian Tribal Governments G. Executive Order 13045: Protection of Children from Environmental Health Risks and Safety Risks H. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use I. National Technology Transfer Advancement Act J. Executive Order 12898: Federal Actions to Address Environmental Justice in Mi nority Populations and Low
Income Populations I. General Information A. Does this action apply to me ? Categories and entities potentially regulated by this proposed rule include:

Category NAICS code 1 Examples of regulated entities Industry.... 327310 Cement manufacturing Federal government... Not affected. State/local/tribal government... Not affected.

1 North American Industry Classification System. This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be regulated by this action. To determine whether your facility would be regulated by this action, you should examine the applicability crite ria in 40 CFR 60.60 (subpart F). If you have any questions regarding the applicability of this proposed action to a particular entity, contact the person listed in the preceding FOR FURTHER INFORMATION CONTACT section.7

B. What should I consider as I prep are my comments to EPA ? Do not submit information containing CBI to EPA through www.regulations.gov or e -mail. Send or deliver information identified as CBI only to the following address: Roberto Morales, OAQPS Document Control Officer (C404
- 02), Office of Air Quality Planning and Standards, Environmental Protection Agency, Research Triangle Park, NC 27711, Attention Docket ID No. EPA
HQ - OAR- 2007
- 0877. Clearly mark the part or all of the information that you claim to be CBI. For CBI information in a di sk or CD
- ROM that you mail to EPA, mark the outside of the disk or CD
- ROM as CBI and then identify electronically within the disk or CD
- ROM the specific information that is claimed as CBI. In addition to one complete version of the comment that includes i nformation claimed as CBI, a copy of the comment that does not contain the information claimed as CBI must be submitted for inclusion in the public docket. Information so marked will not be disclosed except in accordance with procedures set forth in 40 CFR part 2. C. Where can I get a copy of this document ? In addition to being available in the docket, an electronic copy of this proposed action is available on the Worldwide Web (WWW) through the Technology Transfer Network (TTN). Following signature, a copy of this proposed action will be posted on the TTN’s policy and guidance page for newly proposed or promulgated8

rules at http://www.epa.gov/ttn/oarpg . The TTN provides information and technology exchange in various areas of air pollution control. D. When would a public hearing occur ? If anyone contacts EPA requesting to speak at a public hearing by [INSERT DATE 10 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER], a public hearing will be held on [INSERT DATE 15 DAYS AFTER DATE OF PUBLICATION I N THE FEDERAL REGISTER]. Persons interested in presenting oral testimony or inquiring as to whether a public hearing is to be held should contact Mr. Keith Barnett, listed in the FOR FURTHER INFORMATION CONTACT section, at least 2 days in advance of the h earing. II. Background Information on Subpart F A. What is the statutory authority for the proposed amendments to subpart F ? New source performance standards (NSPS) implement Clean Air Act (CAA) section 111(b) and are issued for categories of sources whi ch EPA has listed because they cause, or contribute significantly to, air pollution which may reasonably be anticipated to endanger public health or welfare. The primary purpose of the NSPS is to attain and maintain ambient air quality by ensuring that the best demonstrated emission control technologies are installed as industrial infrastructure is modernized. Since 1970, the NSPS have been successful in9

achieving long
- term emissions reductions in numerous industries by assuring cost
- effective controls ar e installed on new, reconstructed, or modified sources. Section 111 of the CAA requires that NSPS reflect the application of the best system of emission reductions 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. See CAA section 111(a)(1). This level of control is commonly referred to as best demonstrated technology (BDT). In assessing whether a standard is achievable, EPA mu st account for routine operating variability associated with performance of the system on whose performance the standard is based. See National Lime Ass’n v. EPA , 627 F. 2d 416, 431
- 33 (D.C. Cir. 1980). T oday’s proposal considers all of these factors, in cluding both short
- and long
term operating variability associated with potential control technologies. Common sources of information as to what constitutes a best demonstrated technology, and for assessing that technology’s level of performance, include best available control technology ( BACT ) determinations made as part of new source review, emissions limits that exist in State and Federal permits for recently permitted sources , and emissions test data for10

demonstrated control technologies collected for compliance demonstration or other purposes. EPA compares permit limitations and BACT determination data with actual performance test data to insure that permitting and BACT limitations are representative of actual performance and also to identify any site specific factors that could influence general applicability of the information to the entire source category. EPA also carefully examines t est data to insure th at control device s were properly designed and operated during the test. Section 111(b) ( 1)(B) of the CAA requires EPA to periodically review and revise these standards of performance, as necessary, to reflect improvements in methods for reducing emissions. We promulgated Standards o f Performance For P ortland C ement P lants (40 CFR part 60, subpart F) on December 23, 1971 (36 FR 24876). Since then, we have conducted three reviews of the standards (39 FR 20793, June 14, 1974; 39 FR 39874, November 12, 1974; and 53 FR 50354, December 14, 1988 ) . B. What are the current Portland Cement Plant (P CP) NSPS ? The PCP NSPS applies to new, modified, and reconstructed affected facilities in the portland cement manufacturing industry that commenced construction , reconstruction, or modification after August 17, 1971. Affected facilities at PCP include the kiln, clinker cooler, raw mill system, finish mill system, raw mill dryer, raw material storage, clinker storage,11

finished product storage, conveyor transport points, bagging and bulk loading and unloading systems. Unless otherwise noted, the term “new” as used in this preamble includes newly constructed, modified or reconstructed units. III. Summary of the Proposed Amendments to Subpart F The proposed amendments to subpart F of 40 CFR part 60 are summarized in Table 1 of this preamble.

Table 1. Summary of the Proposed Amendments Citation Proposed change 60.62 Change the title of §60.62 to standards. Revise

paragraph (a)(1) to include paragraph (a)(1)(i) which specifies that the current emission limit for particulate matter (PM) applies to kilns constructed, reconstructed, or modified after August 17, 1971 but on or before [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER]. Add a paragraph (a)(1) (ii) which limits PM emissions for kilns that commence construction, reconstruction , or modification after [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER], emissions to 0.086 pounds of PM per ton (lb/ton) of clinker. Revise paragraph (a)(2) to clarify that the opacity limit does not apply to kilns constructed, reconstructed, or modified after August 17, 1971 but on or before [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER] that use a bag leak detection system or PM continuous emission monitoring system. Add paragraph (a)(3) which requires kilns constructed, reconstructed, or modified after [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER] to meet a nitrogen oxides (NO x ) emission limit of 1.5 0 lb/ton of clinker on a 30
- day, 24
- hour rolling average basis. Add paragraph (a)(4) which requires kilns constru cted, reconstructed, or modified after [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER] to meet either a sulfur dioxide (SO 2 ) emission limit of 1.33 lb/ton of12
clinker on a 30
- day, 24
- hour rolling average basis or demonstrate a 90
-percent reduction in S O 2 emissions from the kiln. Revise paragraph (b)(1) to include a paragraph (b)(1) (i) which specifies that the current PM limit applies to clinker coolers constructed, reconstructed, or modified after August 17, 1971 but on or before [INSERT DATE OF PUB LICATION IN THE FEDERAL REGISTER]. Add a paragraph (b)(1) (ii) which limits PM emissions from clinker coolers construct ed , reconstruct ed , or modifi ed after [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER] to 0.086 pounds of PM per ton (lb/ton) of clinker . Revise paragraph (b)(2) to clarify that the opacity limit does not apply to clinker coolers constructed, reconstructed, or modified after August 17, 1971 but on or before [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER] that use a bag leak detection system or PM continuous emission monitoring system. 60.63 Revise paragraph (a) to correct applicability term

(“subpart” instead of “part”) and add the word “clinker” before the phrase “production rate” to clarify that daily recordkeeping requirement is for clinker production rate. Revise paragraph (b) to include paragraph (b)(1) which specifies monitoring requirements for kilns and clinker coolers constructed, modified, or reconstructed after August 17, 1971 but on or before [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER]. Paragraph (b)(1)(i) contains the current requirements for continuous opacity monitoring systems (COMS). Paragraphs (b)(1)(ii) and (iii) allow the source to install a bag leak detection system or a PM CEMS in lieu of a COMS. Also revise paragraph (b) to include paragraph (b)(2) which specifies monitoring requirements for kilns and clinker coolers constructed, modified, or reconstructed or after [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER]. Paragraphs (b)(2)(i) and (ii) require the source to install a bag leak detection system or a PM continuous emission monitoring system. Revise paragraph (c) to clarify that the alternative for visible emission monitoring applies to the requirement in paragraph (b)(1)(i) for a continuous opacity monitoring system.13 Add paragraph (f) to which specifies installation and operation requiremen ts for bag leak detection systems. Add paragraph (g) which specifies the required installation, operation, and maintenance procedures for a PM continuous emission monitoring system. Add paragraph (h) which specifies requirements for weight measurement system for clinker production from kilns constructed, modified or reconstructed on or after [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER]. Add paragraph (i) to require a NO x continuous emission monitoring system for each kiln subject to the NO x emission limit. Add paragraph (j) to require a SO 2 continuous emission monitoring system for each kiln subject to the SO 2 emission limit. Add paragraph (k) to require that NO X and SO 2 continuous emission monitoring systems be installed, operated, and maintained according to Performance Specification 2 of Appendix B to part 60 and that monitors comply with quality assurance requirements in Procedure 1 of Appendix F to part 60. Add pa ragraph (l) to require that NO X and SO 2 monitors record data during all periods of operation. Add paragraph (m) to require a continuous exhaust flow rate monitoring system for each kiln subject to the NO x or SO 2 emissions limit. Add paragraph ( n ) to re quire the use of an electrostatic precipitator (ESP) predictive model to monitor the performance of ESPs controlling PM emissions from kilns or clinker coolers. 60.64 Revise paragraph (b)(1) to add definition of the term

“P” in Equation 1 for new kilns subject to PM emission limit in lb/ton of clinker production. Add paragraph (b)(5) to require repeat PM performance tests (every 5 years) for kilns and clinker coolers. Add paragraph b(6) to require visible emissions monitoring for sources other than kilns and clinker coolers. Add paragraph ( c ) which specifies procedures for converting concentration of NO x and SO 2 to pounds per ton of clinker produced (30 day rolling average). 60.66 Update to specify authorities to be retained by the

Administrator. IV. Rationale for the Proposed Amendments to Subpart F14

A. How is EPA proposing to change the emission limits for future affected facilities ? For “new” affected facilities constructed, modified, or reconstructed after [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER], we are proposing:

 To change the format of the PM emission limits f rom lb/ton of dry feed to lb/ton of clinker product ;

 T o reduce the PM emission limit for kilns from 0.3 lb/ton of dry feed to 0.086 lb/ton of clinker;

 T o set a limit on NOX emissions from kilns of 1.5 0 lb/ton of clinker; and

 T o set a limit on SO 2 emissions from kilns of 1.33 lb/ton of clinker , or, in the alternative, demonstrate a reduction in SO 2 emissions from the kiln of at least 90 percent;

 T o reduce the PM emissions limit for clinker coolers from 0.1 lb/ton dry feed to 0.086 lb/ton of clinker ; and

 T o add new monitoring options of a bag leak detector or PM continuous emission monitoring systems (CEMS) for kilns and clinker coolers to demonstrate compliance with the PM limits in lieu of the requirement for continuous opacity monitoring systems (COMS).15

The emission limits for affected facilities constructed, modified, or reconstructed before [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER] remain unchanged. In determining BDT we generally look at the controls and control performance of new sources. In the case of cement kilns we reviewed recently issued permits and BACT determinations issued by S t ates to identify emissions limits more stringent than the current subpart F (and to understand if limits more stringent than those in subpart F are commonplace or rare , or cover additional air pollutants ). We believe that the use of State permit data and BACT determination developed as part of new source review is appropriate because a BACT determination evaluates available controls, their performance, cost, and non
air environmental impacts. The main difference between those determinations and a BDT dete rmination for purposes of a new source performance standard is that a BACT determination is made on a site
- specific basis. Therefore, in evaluati ng BACT determination s , we have to account for any site
- specific factors that may not be applicable to the sou rce category as a whole. We have also reviewed data gathered in support of related rules involving the p ortland cement industry, notably the National Emission Standards for Hazardous Air Pollutants ( NESHAP ) for p ortland cement kilns issued pursuant to sec tion 112 of the CAA ,16

and the NESHAP for hazardous waste
- burning Portland cement kilns, also implementing section 112 of the CAA . We also collected emissions test data from a number of sources. The emission test data is used to verify the achievable performance of the controls, and to evaluate whether or not the permit levels reviewed accurately reflect control device performance. Our review of permits and actual test data from portland cement sources, and discussion s with industry representatives and State environmental agencies indicates , not surprisingly, that certain changes have occurred since the 1988 review of the NSPS , and that these changes are still continuing . We found that older, less energy efficient wet and long dry kilns are being replaced with preheater/precalciner kilns because preheater/precalciner kilns have superior energy efficiency and increased clinker capac ity . 1 According to the industry, all new kilns will be preheater/precalciner kilns. 1 We confirmed this by reviewing a detailed listing of portland cement kilns which indicates that since 2000 all kilns constructed or modernized

are of the preheater/preca lciner design. 1 The information also revealed (again, not surprisingly) that recently built kilns are subject to more stringent limits

1 Technical Support Document for Portland Cement NSPS Review. May 2008.17

on their emissions through S tate permitting processes than those currently in the PCP NSPS. In addition, many S tate permits contain emission limits for NO X and SO 2, pollutants that are not regulated under the current NSPS. 1 Modern preheater/precalciner kilns and improved combustion process designs and add
- on controls that greatly lower NO X emissions are increasingly b eing used to meet S tate permit limits. Our review of permits, BACT determinations , and emissions test data show that SO 2 emissions are typically low as a result of the inherent scrubbing action of alkaline raw materials in the kiln and raw mill as well as the typically low sulfur content of raw materials and fuel. However, there are a few locations where the raw materials used in production of clinker contain high levels of sulfur. In these few situations, wet scrubbers or dry lime sprayers have been used to reduce SO 2 emissions in order to meet S tate SO 2 limits. Preheater/precalciner kilns have in
- line raw mills, which means that the kiln exhaust gas is routed to the raw mill and then to the final PM control device. Therefore, the kiln and raw mill exhaust through the same stack. In order to maximize energy efficiency, facilities ro ute as much clinker cooler exhaust as possible to the kiln (typically as tertiary air), and sometimes to the raw mill to recover heat from the clinker cooling operation. However, typically some portion of the18

clinker cooler gas flow exhausts directly to a tmosphere through its own stack so that clinker coolers are one of the enumerated units covered by the NSPS, and one of the emission points addressed by these proposed amendments. As previously mentioned , older kilns are typically replaced with new preheat er/precalciner kilns rather than being modified or reconstructed. However, because modified and reconstructed kilns are also subject to NSPS, we evaluated the situation where an existing kiln becomes subject to NSPS through modification or reconstruction. We identified only two instances since 1990 where an existing kiln was significantly modified rather than replaced with a new kiln, so we do not expect this to be a common occurrence. Moreover, i n one such case a wet kiln was converted to a semi
- dry pro cess that included a preheater/precalciner. Performance data from this kiln indicate that the emissions of SO 2 and NO x are actually lower than would have been expected if the kiln had been replaced with a new preheater/precalciner kiln. 2 Therefore, we expect that the emission limits proposed for new preheater/precalciner kilns would be applicable to this type of conversion. In the second case, a long dry kiln was shortened and a preheater/precalciner

2 Lone Star’s Unique Approach to Environmental Challenges . O.P. Jepsen and B.P. Keefe, Fuller Company, Cement Industry Technical Conference, IEEE
- IAS/PCA, 2001.19

added. A modification of this type would be expected to use the same technology in the precalciner/preheater section as a new preheater/precalciner kiln and the resulting modified kiln would basically be the same as a new kiln from the standpoint of criteria pollutant emissions control. Accordingly, EPA beli eves that the limits proposed today are appropriate for new, modified, and reconstructed kilns since the preheater/precalciner design will be utilized in each of these instances. 1 . Format of the Standard The current NSPS limits for PM are expressed on a pound of PM per ton (lb/ton) of dry feed input format. Emission limits are typically normalized to some type of production or raw material input value because this allows comparison ( and ultimately the abi lity to set a single standard) for different sized facilities. (A common example of normalization is expressing vehicle fuel economy in terms of miles of gasoline per vehicle mile traveled, e.g. miles per gallon.) The 1971 NSPS uses a pound of pollutant per ton dry feed basis as the normalizing parameter. In these proposed amendments we are adopting a new normalizing parameter of lb/ton of clinker

– i.e. normalizing based on kiln output rather than input for sources constructed, reconstructed or modified after [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER] .20

Adopting an output
-based standard avoids rewarding a source for becoming less efficient, i.e., requiring more feed to produce a unit of product, therefore promoting the most efficient producti on processes. As an example, a ssume a cement kiln rated at 1.2 million tons per year (tpy ) has a NOX emission limit of 1.5 lb/ton of clinker (output) . The equivalent input
based limit would be 0.909 lb/ton of feed (on average 1.65 tons of feed produces one ton of clinker , so a kiln rated at 1.2 million tpy clinker uses 1.98 million tpy of feed ). Under either an input
- or output -based standard , the maximum allowed NOX emissions would be 900 tpy (1.5 lb/ton clinker x 1.2 million tons clinker ÷ 2000 = 900 tons = 0.909 lb/ton feed x 1.98 million tons feed ÷ 2000) . However, if a facility has a less efficient kiln, for example it requires 1.7 tons of feed to produce one ton of clinker (so the feed i nput is now 2.04 million tons) , this kiln would be allowed to emit 9 27 tpy of NOX (0.909 lb/ ton feed x 2.04 million tons feed ÷ 2000) under the input
-based standard of 0.909 lb/ton of feed, but still only 900 lb per year of NO X under the 1.5 lb/ton of clin ker output
- based standard. Over the short term, the measurement of kiln output is not as exact as the measure of kiln input. For this reason, we are basing compliance with the proposed NO X and SO 2 emission limits on a 30 day rolling average. We believe this will alleviate the21

issues related to the inaccuracy of short
- term output measurements. However, industry has requested the option to convert to an input
-based standard to accommodate site
- spec ific configurations and operational limitations. 3 In the following discussions, emissions were typica l ly reported as a concentration or per ton of feed. The BACT permit limits discussed were typically based on output. We have converted all the data to a n output based standard using a conversion factor of 1.65 tons of input equals one ton of clinker. More information on conversion may be found in the technical support document (see footnote 1). We are specifically requesting comment on the benefits of an output -based standard, output measurement methods and their associated errors, provisions that would allow a site to convert to an input
-based standard , any limitations we should impose on conversion, and the appropriate averaging times. Information o n how conversions from input
-based emission limits and test data and / or concentration
-based data to output -based limits and test data may be found in the Techn ic al Support Document for the Portland Cement NSPS review (See Footnote 1). 2 . PM

3 Email, H. Ybanez, Holcim, Inc to K. Barnett, EPA, February 27, 2008.22

The most effective control devices to reduce PM emission from cement kilns and clinker coolers identified in the original NSPS were fabric filters and electrostatic precipitators ( ESPs ) . These continue to be the most effective PM controls in use, capable of removing over 99.9 percent of the PM from the exhaust gas. At the time of the 1988 review, 17 new kilns that had become subject to the NSPS since the 1979 review were controlled by fabric filters and 13 by ESPs. Of the 21 clinker coolers with a separa te exhaust stack that had become subject to the NSPS , 17 were controlled by fabric filters, and four were cont rolled by gravel bed filters. ( Gravel bed filters perform similarly to fabric filters except they use a moving bed of gravel to capture the parti culate rather then cloth or membrane fabric. We do not expect new facilities to install gravel bed filters ) . Though ESPs and fabric filters have comparable removal efficiencies based on short
- term tests, recently built new kilns have fabric fil ters as PM controls, and we expect this trend to continue. ESPs applied to cement kilns must be deenergized if the carbon monoxide ( CO ) or excess air levels rise above a preset critical level where an explosion could occur, which results in short periods of high emissions. The high resistivities of PM from a cement kiln require gas conditioning if an ESP is used. In addition, resistivity can change if the23

chemistry of the clinker changes. ESP performance can also be affected by the particle size distribution. Fabric filters are not affected by these factors, and fabric filters control generally to the same concentration irrespective of the PM loading at the filter inlet, though some variability in PM emissions f rom fabric filters does occur due to seepa ge and leakage. 4 Therefore, we expect the long
- term performance of a fabric filter to be superior to an ESP. For this reason, we believe that well
- operated and maintained fabric filters are the best technology for control of PM emissions at portland cement kilns, and so are basing this part of the proposal on use of fabric filters for PM control. In assessing the level of performance constituting BDT (i.e. the level of performance achievable by well
- operated and maintained fabric filters in th is indus try considering normal operating variability) we reviewed data on PM limits in eight recently issued permits for new cement kilns, all of which are equipped with fabric filters. The permit limits for PM for these kilns were in various units, but were converted to a lb/ton output basis. 1 The PM limits ranged from 0.093 to 0.28 lb/ton of clinker, and the average was 0.16 lb/ton. In order to determine if the permitted PM emissions limits were

4 Technical Support Document for HWC MACT Standards

– Volume I: Description of Source Categories , U.S. Environmental Protection Agency. September 2005 , Section 3. 2.24

representative of actual performance we reviewed two data sets

me asured by EPA Reference Method 5 (40 CFR part 60, Appendix A
3). The first set was comprised of 21 emission tests of p ortland cement kilns equipped with fabric filters at various domestic locations which fabric filters were ( reportedly ) equipped with memb rane bags. These PM emis sions ranged from 0.0023 up to 0.4724 lb/ton of clinker with a median of 0.1360 lb/ton. Fifteen of the 21 tests were below 0.16 lb/ton of clinker . All of the tests where the emissions were above 0.16 lb/ton of clinker , except one , were on kilns that were not preheater/precalciner kilns. The one test on a preheater/precalciner that was above 0.16 lb/ton of clinker was
on a kiln built in 1981. Therefore, we have reason to doubt that the data above 0.16 lb/ton of clinker are repres entative of the most current designs. We also reviewed 37 emissions tests for PM from Florida kilns e quipped with fabric filters where the bag type was unknown. The range was 0.015 to 0.153 lb/ton of clinker , so all 31 tests were below 0.16 lb/ton. Alth ough these are single test results, and so are unlikely to reflect all the operating variability associated with air pollution control device performance, these data still suggest that a limit of 0.16 lb/ton of clinker is achievable by new cement kilns equ ipped with a fabric filter.25

We also evaluated the performance of fabric filters using membrane bag technology, generally considered the most efficient type of fabric filter. Membrane bags have superior performance to the cloth bags that are part of the standard fabric filter design. Cloth bags capture PM in the interstices of the woven fabric and form a primary dust cake. Until the primary dust cake forms cloth bags are inefficient as filters. Therefore, each time the bag is cleaned emissions increase until the primary dust cake reforms. Emissions also occur when the pressure drop becomes so high that the PM migrates completely through the fabric. Membrane bags , in contrast, operate under the princip le of surface filtration, i.e. , the PM is captured on the surface of the bag. This results in more consistent performance (no need to build up a primary dust cake). In addition, at a constant airflow membrane bags reduce the average pressure drop across the fabric filter. However, membrane bags

are more expensive than cloth bags. 5 We reviewed 19 emission tests conducted on four p ortland cement kiln s where we were able to establish that the facilities used fabric filters with membrane bags, and where the kilns had been built in the last 10 years, so we could be reasonably certain the control device was representative of the latest

5 Cement Americas “Optimizing Kiln Operations by Improving Baghouse Performance” November 2001, pp . 1
- 5.26

fabric filter design. Thirteen of those tests were on a cement kiln that burns hazardous waste. We believe there is no difference in the performance of a fabric filter for PM applied to a kilns that burn hazardous waste and those that do not because PM emissions are largely contributed by non
- hazardous waste feed streams, and because fabric filters control PM emissions generally to the same concentration irrespective of the PM loading at the inlet ( see 69 FR 21225 and 21233). The individual test results converted to an output basi s ranged from 0.0023 to 0.10176 lb/ton of clinker with an average of 0.0357 lb/ton . In order to account for variability, we analyzed the statistical variation by calculating a standard deviation of the test averages, multiplying the standard deviation by the t value for the 95 th or 99 th percentile, and adding this value to the average of all the tests. The result was we determined that a level of 0.0 830 lb/ton of clinker represented an emissions limit that will not be exceeded 95 percent of the time and a level of 0.1025 lb/ton of clinker represented an emissions limit that will not be exceeded 99 percent of the time. EPA has also performed a differe nt statistical analysis of the data from the hazardous waste
-burning cement kiln equipped with a membrane fabric filter , applying to the data a so
- called universal variability factor derived from the performance of the best performing (lowest emitting) PM performers equipped with fabric27

filters across the hazardous waste combustor source category. This variability factor quantifies both short
- term and long
- term operating variability, i.e. , variability associated with the conditions of the individual compli ance test and variability associated with the performance of the control equipment over time. See generally 72 FR 54878
- 79 , Sept ember 27, 2007. (This approach is more sophisticated, since it accounts for both short
- term and long
- term variability, whereas variability in the individual runs comprising the compliance tests (i.e. , the 95th or 99th percentile of those data), is more a measure of short
term variability alone, see 72 FR 54878) . The standard under this analysis is 0.0069 gr/dscf corrected to 7 p ercent oxygen. See 71 FR 14669 , March 23, 2006. Using a typical value of 54,000 dry standard cubic feet ( dscf ) of exhaust produced per ton of kiln feed and one ton of clinker producer per 1.65 tons of feed, 0.0069 gr/dscf converts to 0.086 lb/ton of clin ker. 1 We are proposing this level as BDT for PM emitted by new portland cement kilns , as measured by EPA Reference Method 5 in 40 CFR part 60, Appendix A
- 3 . Our analysis of individual stack results from the newer kilns equipped with membrane bag
- equipped fabric filters confirms that the level is achievable, the level is between the 95th or 99th percentile of those data, and as just explained, this level acco unts for all of the potential28

operating variability associated with operation of a membrane
bag fabric filter. We evaluated the costs of the different control levels discussed above. This evaluation, and all subsequent cost, environment, and energy impa cts on a per kiln basis are based on a model preheater/precalciner kiln with a rated capacity of 1.2 million tpy of clinker. The average capacity of kilns which were constructed beginning in 2000 and were operating in 2006 was approximately 1.3 million tp y. We choose a model kiln with a capacity slightly lower than average to provide a more conservative cost estimate (smaller kilns tend to have a greater control cost per ton of capacity). The other kiln design specifications (flue gas flow rates, tempera tures, etc.) may be found in the Technical Support Document (See F ootnote 1). Based on our assessment that all new fabric filters with standard cloth bag will achieve a level of 0.16 lb/ton of clinker, and that new kilns would at least be equipped with this type of fabric filter, there are no costs or other impacts associated with meeting a PM emissions limit to 0.16 lb/ton of clinker . There are a variety of regulatory reasons that new kilns, on average, currently meet a 0.16 lb/ton of clinker PM limit, and we believe it is appropriate to use this level as the baseline in our cost analysis. We considered using a baseline of 0.5 lb/ton of clinker (equivalent to the current NSPS).29

However, not only is this level inappropriate because it does

no t reflect current operating performance, but choosing 0.5 lb/ton of clinker as the baseline would not have changed our decision in any case. To achieve a level of 0.086 lb/ton of clinker , a new kiln with a capacity of 1.2 mill ion tpy of clinker productio n may have to equip the fabric filter with more expensive membrane bags at an estimated capital cost of $1.3 million and at a total annualized cost of $176,000 per year. This includes additional operating and maintenance costs, and amortized capital costs . The estimated emission reduction over the baseline would be 44 tpy for the model kiln and the cost per ton of additional PM control is $3 , 969 . This cost appears to be reasonable to EPA, given that it is well within the range of cost
- effectiveness for t otal PM control accepted as reasonable for other stationary sources. See, e.g. 7 0 FR 9715 , February 28, 2005 (cost effectiveness of $ 8,400 per ton of total PM considered reasonable for proposed rule for electric utility steam generating units) and 71 FR 9 876, February 27, 2006 promulgating the proposed rule. We also analyzed the cost per ton of fine PM (PM of 2.5 micrometers or less) emissions reduction. Data from development of the PM National Ambient Air Quality Standards (NAAQS) indicate that the majority of the adverse health effects from PM30

exposure are from exposure to fine PM (although exposure to coarse PM is likewise associated with health effects, see 71 FR 61184
- 85 , October 17, 2006) . As a result, EPA established a NAAQS for fine PM separate from the NAAQS for coarse PM . Based on data from EPA’s C ompilation of Emission Factors (AP
- 42), 45 percent of the PM from a cement kiln fabric filter is fine PM. Therefore, t he emissions reduction of fine PM resulting from a total PM standard of 0.086 lb/ton of clinker is 19.8 tpy for the model kiln and the cost per ton of fine PM reduction is $8 , 819. In most cases there would be no non
- air impacts associated with the proposed standard because PM captured in the control device for a preheater/precalciner kiln is mainly raw materials which are recycled back to the kiln, rather then disposed of as solid waste. In the case of a kiln equipped with an alkali bypass, however, additional PM captured in the alkali bypass fabric filter would typically be disposed as a solid waste. This PM is high in alkal i materials and cannot be recycled back to the kiln or mixed with the product. Based on data collected on amounts of solids generated by the PM controls, the solids from the alkali bypass are about 1 percent of total collected solids ( i.e. , 99 percent is collected in the main f abric filter and recycles to the kiln ) . Therefore, the amount of additional solid waste resulting from this proposed PM emissions limit would be expected to be minimal. We do not anticipate any31

adverse energy impacts because membra ne bags reduce control device pressure drop and thus reduce energy use. Given the reasonable costs, and minimal solid waste impacts we are proposing a PM emissions level of 0.086 lb/ton of clinker as BDT. In these proposed amendments, we are continuing to assess compliance based on the filterable PM collected in the front half of the standard EPA Method 5 train as under the existing rule, and under most standards for PM. All information on which the proposed PM standard is based likewise comes form Met hod 5 testing. We are not including condensable particulate, which typically passes through the Method 5 filter, and all of the PM test data previously discussed do not include any condensable particulate. This particulate can exit the stack in a gaseous form, but can react in the atmosphere to form fine particles (so
- called secondary PM discussed below). We have insufficient data to assess if the cement industry is a significant source of condensable PM. None of the test data we evaluated include conde nsable PM. We are specifically requesting comment on the levels of condensable PM emitted by the cement industry; any condensable PM emission test data collected using EPA Conditional Method 39, EPA Method 202 (40 CFR part 51, Appendix M) , or their equivalent, factors affecting those condensable PM emissions, and potential controls.32

As previously noted, fabric filters are also the predominant control for another emission point, clinker coolers. Included in the 1988 review of the NSPS wer e 12 PM emissions tests for clinker coolers where the coolers had separate stacks. One test was performed under abnormal operating conditions and

so was not used in our analysis. The remaining 11 tests showed a PM emissions range of 0.008 to 0.05 lb/ton of feed , which converts to 0.013 up to 0.083 lb/ton of clinker. 6 Tests on three clinker coolers associated with prehea ter/precalciner kilns built in the last 10 years using fabric filters for PM control showed a range of 0.0038 to 0.0094 lb/ton of feed wh ich converts to 0.0063 to 0.01551 lb/ton of clinker. Based on these test data, we believe that the current clinker cooler controls used on new sources can meet the same level of PM control as a kiln with membrane bags, i.e. 0.086 lb/ton of clinker . Since new facilities are already installing controls (usually fabric filters) capable of meeting the proposed clinker cooler limit of 0.086 lb/ton of clinker , the incremental costs of the proposed emissions limit would be very low or zero, as would any non
- air environmental and energy impacts.

6 Portland Cement Plants

– Background Information for Proposed Revisions to Standards. EPA
- 450/3

- 85
- 003a, May 1985. pp. 4
- 9 to 4
- 13 and C
- 2 to C
- 5.33

We considered proposing a limit below 0.086 lb/ton of clinker for clinker coolers, based on the emissions shown for the three newer facilities. Based on these data a limit of 0.0245 lb/ton of clinker (representing the 99th confidence interval) would be achievable for new sources. However, we believe that these limited data are not sufficient to support a lower PM limit for clinker coolers, since these data are unlikely to fully reflect control device operating variabi lity. We are requesting comment , however, on the achievability of a lower PM emission limit for clinker coolers. 3 . NOX 7 The current NSPS does not regulate the emissions of NO X . Concurrent with this 8
- year review we are proposing an NSPS for NOX that wou ld apply to kilns constructed, modified, or reconstructed after [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER] . The high temperatures and oxidizing atmospheres required for cement manufacturing are favorable for NO X formation. In cement kilns, NO X emissions are formed during fuel combustion primarily by the oxidation of molecular nitrogen

7 Information on NO X emissions from preheater/precalciner kilns, factors affecting NOx emissions, process controls that reduce NO X emissions, staged combustion, selective noncatalytic reduction, selective catalytic reduction and more can be found in the EPA publication “Alternative Control Techniques Document Update

– NOX Emissions from New Cement Kilns, EPA
- 453/R

- 07
- 006, November 2007, and is available on EPA’s Technology Transfer Network at http://www.epa.gov/ttn/oarpg

.34

present in combustion air (referred to as thermal NO X ) and the oxidation of nitrogen compounds in fuel (referred to as fuel NOX ). Many S tates issuing construction and operating permits for new kilns have specified emission limits for NO X . EPA’s BACT/RACT/LAER Clearinghouse database shows that for the period 2001 through 2007, 30 determinations for new, modified or reconstructed kilns included NO X limits. Emission s of NOX are typically reduced through process controls such as burner design (low
-NOX burners) and staged combustion in the calciner (SCC). NOX emissions from kilns using process designs such as low NO X burners and SCC emit on average about 2.5 lb/ton of clinker . The exclusive add
- on control used to reduce NO X emissions from kilns operating in the U.S. is selective noncatalytic reduction (SNCR). In Europe, selective catalytic reduction (SCR) has been used to reduce NO X emissions from a few cement kilns. In recent Prevention of Significant Deterioration permits for portland cement kilns, S tates have determined BACT emission limits for NO X based on the use of SNCR in combination with well
- designed SCC and other process designs such as low NO X burners. In SNCR systems, a reagent such as ammonia or urea is injected into the flue gas at a suitable temperature zone, typically in the range of 1 , 600 to 2 , 000°F and at an appropriate ratio of reagent to NOX . SNCR system performance depends on temperature, residence time, turbulence, oxygen content, and other factors specific to35

the given gas stream. On average, SNCR achieves approximately a 35 percent reduction in NO X at a ratio of ammonia
- to - NOx of about 0.5 and a reduction of 63 percent at an ammonia
- to - NOx ratio of 1.0. At the high ratios, including ratios above 1, some ammonia may not react with NO X and will be emitted. The unreacted ammonia is referred to as ammonia slip. Ammonia may have a detectable odor at or above 5 parts per million ( ppm ) . It can also produce a visible stack plume when the ammonia forms ammonia chlorides. Under certain atmospheric conditions ammonia can also react with nitrates and sulfates, both of which can be available in ceme nt kiln exhaust, to form fine PM emissions , see 69 FR 4583 , January 30, 2004, and ammonia itself is a pollutant under the CAA . Limits on ammonia slip are often imposed by permits or design requirements, which in some instances constrain the NO X reduction achievable by an SNCR system. Another NO X control technology, SCR, is used in the electric utility industry to reduce NO X emissions from boilers and has been used worldwide on three cement kilns in Europe. SCR is capable of reducing NO X emissions by abo ut 80 percent. Though SCR is demonstrated in Europe, SCR has never been used on any cement kilns in the U.S. Uncertainties exist as to its specific performance level and catalyst plugging and fouling, which affects operating costs . (See discussion below).36

One control option considered was to make to make no changes in the current NSPS and thus not regulate NO X emissions. However, we rejected that option because , NOX is unquestionably emitted by cement kilns, is currently controlled at most new cement kilns, and, based on our review of recently issued permits, demonstrated technologies are available to reduce NO X emissions considering costs and other impacts. In proposing a NO X emission limit, we reviewed recently issued permits, recent BACT determinations and recent emissions data for preheater/precalciner kilns to establish potential NO X control levels for evaluation. Most of the emission limits and test data are 30 day avera ges based on data from continuous emissions monitors . A first step in doing so is to establish a baseline from which control options can be evaluated. NO X emissions from three recently permitted preheater/precalciner kilns utilizing well
- designed and operated process designs including SCC, averaged NO X emissions of 1.62, 1.88 and 1.97 lb/ton of clinker. These levels are achieved at kilns that are not equipped with additional add
- on controls. While demonstrating the capabilities of kilns utilizing well
- designed process controls including SCC but not add
- on controls , these emission levels are not necessarily representative of what all new kilns would achieve even with similar process designs. Several factors can influence NO X emissions. Changes in the kiln37

feed rate, chemical composition, or moisture content of raw materials can cause kiln temperatures to vary with significant variation in NO X emissions. Even raw materials from the same quarry can vary in chemic al composition from day to day. Burnability is an issue where certain raw materials require higher temperatures and longer heating times to properly calcine the materials . For example, raw materials that contain high alkali content must b e heated longer and at higher temperatures to volatilize and remove the alkali compounds. With higher temperatures and longer residence times, NO X emissions may increase. Based on data from equipment vendors and representatives from facilities with more difficult
- to - burn raw materials, we believe that future well
- designed and operated cement kilns, which will incorporate SCC and low
-NOx burners, will meet a level of 2.5 lb/ton of clinker on average, without consideration of end
- of
- stack air pollution cont rol. Therefore,

we are using this level as the baseline level of control that would occur with no additional regulatory action. However, we know that in some applications the level achieved even when using low
-NOX burners, indirect firing and well
- designed SCC may be as high as 3 lb/ton of clinker due to the reasons, such as burnability, discussed above. We considered choosing a s baseline of a new preheater/precalciner kiln designed without SCC or low NOx38

burners , i.e. a completely uncontrolled kiln . For a variety of regulatory reasons, the newest kilns based on the most current designs of which we are aware all incorporate low NO x combustion technologies. Therefore we have no data to determine the app rop r iate NO x emission level for a new preheater /precalciner kiln that does not incorporate low
- NO x burners and SCC. In addition, choosing 2.5 lb/ton of clinker as our baseline versus a higher number would not have changed our decision on the proposed NO X level. The second control we evaluated was 1.95 lb/ton of clinker, which is the most common level established as BACT in recent permits for new cement kilns. 8 As previously noted, some new kilns meet this level of control using low
- NOx burners and SCC. However, we expect that, on average, new facilities would require only a modest SNCR removal efficiency of 22 percent SNCR to meet this level from the uncontro lled industry average 2.5 lb NOX /ton of clinker, which is well within the range demonstrated for SNCR control efficiency in this industry. The third control level we evaluated was 1.5 lb/ton of clinker, and was established based on our assessment of the best demonstrated performance utilizing optimal process design, including SCC, and SNCR taking into account variability of such

8 Memorandum from M. Bahner, RTI, to M. Laney, RTI, and K. Barnett, EPA, Review of Three BACT Analyses, October 10, 2007 .39

factors as the burnability of raw material inputs, which can affect NO X emissions. Data on SNCR show a performance that ranges from approximately 20 to 80 percent NO X reduction. Since NOX levels of 1.62 to 1.97 lb/ton of clinker are demonstrated for kilns using well
- designed SCC, a level of 1.5 lb/ton of clinker would be easily achievable even with SNCR removal efficiencies in the lower range of demonstrated SNCR performance . Generally, SNCR performance (i.e. percentage removed) increases as uncontrolled NO X levels increase. For example, SNCR performance in which a reagent was injected into a flue gas at a temperature of 1 , 800°F , a 41 percent NO X removal efficiency was obtained at a 70 ppm; at 200 ppm the NO X removal efficiency increased to 54 percent. We estimate that for an SNCR with optimal injection configuration and reagent injection rate, a 50 pe rcent NO X emission reduction represents a reasonable level of performance of SNCR over the long term. Although, as noted above, we are projecting that new kilns on average will have emissions of 2.5 lb/ton of clinker prior to the application of add
- on controls, there may be some situations where specific raw materials properties, such as those affecting burnability, will result in higher uncontrolled NO X emissions. For this reason we assumed a maximum baseline of 3.0 lb/ton of clinker and 50 percent

emission reduction by SNCR to establish a 1.5 lb/ton of clinker control level. And where uncontrolled NO X emission levels40

achieved by process design are lower than the assumed maximum baseline of 0.3 lb/ton of clinker , the removal efficiency of SNCR can be lower and still achieve the 1.5 lb/ton of clinker limit. The levels of performance for SNCR are from single test results. By allowing compliance on a 30 day average, we are allowing more operating margin to assure we have accounted for normal operating variability. The results of this analys i s showed that for both the 1.95 and 1.5 lb/ton of clinker levels, the capital costs for the installation are the same, about $2.3 million. Annualized cost s for the 1.95 level are $0.7 million and for the 1.5 level, $1.3 million. The annualized cost of control for the 1.5 level is higher than the annualized cost for the 1.95 level because a higher reagent injection rate would be required to reach the lower limit. Overall c ost effectiveness at the 1.95 lb/ton of clinker level was approximately $2 , 000 per ton of NO X reduction and at the 1.5 lb/ton of clinker level was approximately $2 , 100 per ton of NO X reduction. This level of cost effectiveness for both options compares favorably with the reference range of NO X control cost effectiveness ($200 to $2 , 800) considered highly cost effective in the Clean Air Interstate Rule. See 70 FR 25208 , May 12, 2005. Neither control option results in non
- air environmental impacts. The energy impacts due to electrical demand of the SNCR system are not significant. Given the41

similarity of the cost effectiveness of both options, we are proposing the 1.5 lb/ton of clinker level as BDT. We also evaluated a control level of 0.5 lb/ton of cli nker based on the performance of SCR. SCR is the process of adding ammonia or urea in the presence of a catalyst to selectively reduce NO X emissions from exhaust gases and has been used extensively on gas turbines, internal combustion engines, and fossil fired
- fired utility boilers. The desired chemical reactions are identical with SNCR and SCR. However, SCR uses a catalyst, which allows the reactions to occur at a lower temperature. In SCR systems, ammonia is typically injected to produce an ammonia
- to -NOx ratio of about 1.05 or 1.1 to 1 to achieve a NO X reduction of 80 to 90 percent with an ammonia slip of 10 ppm. At a cement kiln, SCR can be installed either after the PM control device (a low
- dust system) or before the PM control device (a high
- dust system). As noted earlier, three cement kilns have used SCR, all in Europe. Despite the use of SCR on three kilns in Europe, there are several uncertainties as to whether they represent BDT. Of the three kilns in Europe using SCR, two are preheater kiln s, and one kiln is a Polysius Lepol technology kiln, which is a traveling grate preheater kiln. None of the kilns using SCR are preheater/precalciner kilns which are the only type of kiln that will be built in the U.S. Also, one of the European cement42

pl ants has switched back to using its SNCR system to compare the operational costs of the two systems to evaluate which technology is better and more economic al . Because the experience with SCR on cement kilns is so limited, issues have been raised on SCR applicability to cement kilns. Because the optimum operating temperature for most SCR systems is between 600 and 750°F, the ideal location of the SCR system would be downstream of the preheater cyclones and prior to the roller mill, which is also prior to the PM control device. This location results in the SCR system operating in a high
- dust environment. One of the concerns with this location is catalyst plugging and fouling where the accumulation of dust blocks access to the catalyst pores resulting in reduced effectiveness and shortened life span. Because of the problem of catalyst plugging with high
- dust SCR systems, a catalyst cleaning mechanism such as p ressurized air nozzles or sonic horns is necessary. For more thorough cleaning, it is necessary to periodically remove each individual catalyst bed for cleaning using water or other solvent solutions. The resulting wastewater and solids generated during this cleaning process must be properly managed and disposed (an adverse non
- air impact associated with this technolog y’s use). To move exhaust gases past or through the catalyst, there will be an additional pressure drop that may require that existing air
- handling43

equipment, such as fans and blowers, be scaled up. Other concerns include the oxidation of SO 2 to SO 3 by the SCR catalyst, catalyst masking by CaSO 4 formation and the generation of sulfuric acid mist, formation of ammonium sulfate which can foul downstream equipment, and alkali poisoning of catalysts and deactivation of catalyst. Eventually, a catalyst will reach the end of its useful life and need to be replaced with new catalyst elements. If not physically damaged, a catalyst can often be regenerated. If not, it must be properly managed and disposed. T o avoid the issue of plugging and fouling created by a high dust environment, an SCR can be located downstream of the PM control device as a low
- dust system. The disadvantage of a low
dust sys tem is that the SCR system is no longer located in a suitable temperature range and the flue gas must be reheated at a significant cost in order for the injected ammonia to properly react with NO X in the gas stream. Reheating is typically accomplished usi ng a natural gas burner. While the emissions impact of a gas burner would likely be minimal, the amount of energy use would be in the range of 400 to 5 00 trillion Btu for a 1.2 million tpy kiln. If other less expensive fuels are used (such as coal), then emissions of other pollutants such as PM and SO 2 may increase. EPA estimates the costs of installing an SCR system to be $5.7 million in capital cost and $3.1 mil lion annualized cost.44

The resulting average NO X emissions reduction would be 1 , 200 tpy over baseline, and the incremental NO X reduction over the 1.5 lb/ton of clinker control level would be 600 tpy. The average cost effectiveness is approximately $ 2,500 per ton and the incremental cost effectiveness is approximately $3 , 000 per ton of NOX reduction. To determine the reasonableness of this cost effectiveness, we turned to the CAIR rule. Reference cost effectiveness for NO X controls ranged from $200 to $2 , 800 and, for marginal cost effectiveness, $1 , 400 to $ 3 , 000. Highly cost effective controls are considered to be those whose cost effectiveness tends toward the lower ends of the reference range. A cost effectiveness of $3 , 000 for SCR systems on a cement kiln is at or just above the range of average cost effectiveness. It should also be noted that there is considerable uncertainty in the SCR cost estimates due to the technical issues discussed above. If site specific factor s relating to the raw materials do cause significant plugging and fouling, the costs calculated above may be biased low. In addition, SCR increases energy use due to the pressure drop across the catalyst, and as noted above, produces liquid and solid wastes that must be managed. Considering these potential technical operating difficulties with SCR in this industry, somewhat high cost effectiveness, the uncertainty of the costs estimates, and45

adverse non
- air and energy implications, EPA is not proposing SCR as BDT for portland ceme nt kilns. EPA solicits comment on this issue. We expect that all new kilns will be required to install SNCR systems to meet the 1.5 lb/ton of clinker NOX limit. One concern with the use of SNCR is the potential for secondary PM emissions. As explained above, under certain conditions the injected ammonia reacts to form condensable fine PM that is not captured by the fabric filter because it is emitted as a gas. We are requesting comments on the effect that ammonia slip from use of SNCR might h ave in the generation of condensable PM emissions, and what a ction s , if any, are available to mitigate those impacts. 4. SO 2 In the previous NSPS review, we declined to set SO 2 standards because there were no demonstrated add
- on SO 2 control technologies applied to cement kilns (53 FR 50354, December 14, 1988). Since that time at least two SO 2 control technologies have been applied to cement kilns, wet scrubbers and lime injection. The proposed emission limit is based on a review of recent BACT determina tions and emissions test data and takes into account the inherent scrubbing ability of the naturally alkaline raw materials used in the cement
-manufacturing process (70 FR 72337, December 2, 2005).46

In a cement kiln, SO 2 comes from two sources. The first is sulfur in the coal fuel (fuel SO 2 ). Most fuel SO 2 mixes with lime in the kiln and preheater and is not emitted into the atmosphere. The other and potentially more important source of SO 2 is the raw materials (raw ma terials SO 2 ). Sulfides or elemental sulfur in the raw materials may be oxidized to SO 2 in the kiln system where sufficient oxygen is present. Through the inherent scrubbing ability of the alkaline raw materials, this SO 2 is partially removed in the raw mill (50 to 70 percent removal). Raw mills typically operate about 90 percent of the time when the kiln is operating. For most portland cement plants, the levels of sulfur in raw materials are low enough that most of the SO 2 generated is removed by the na tural scrubbing action of the kiln raw feed. However, in those instances where the sulfur content of raw materials is great due to the presence of pyritic sulfur, uncontrolled SO 2 emissions can be significant. Add
- on controls may be necessary in those sit uations. Cement kilns faced with high SO 2 emissions due to high sulfur levels in raw materials have used either wet scrubbers or lime injection for SO 2 emission control. Wet scrubbers applied to cement kilns typically achieve at least a 90 percent or mor e47

reduction in SO 2 emissions. 9 A recently installed scrubber on a cement plant with high uncontrolled SO 2 emissions due to high
sulfur raw materials was designed to achieve a 95 reduction in SO 2 emissions. 10 A 95 percent SO 2 reduction is consistent with ot her information on the performance of scrubbers for SO 2 removal. 11 Assuming the wet scrubber is correctly si z ed (typically a liquid
- to - gas ratio of 30 gallons per 1 , 0 00 actual cubic feet per minute) , the percent removal can vary based on inlet concentration (higher inlet concentrations result in a higher percent reduction) and scrubber pH. Lime injection consists of injecting lime into a duct downstream of the preheater, or in some cases injecting lime into the first two preheater stages to remove SO 2 . At some facilities lime injection is only used when increases on SO 2 emission above a specified level are detected, such as when the raw mill is down. The percent reduction in SO 2 emissions is a function of the inlet SO 2 concentrations and lime injection rates. Increasing either increases the percent reduction in SO 2 emissions. Dry lime systems can reportedly achieve a SO 2 emission s reduction of up to approximately 70 to 75 percent, though one vendor claims potential reduction s of up to 90

9 Summary of Cement Kiln Wet Scrubber and Lime Injection Design and Performance Data, May 2, 2008. 10 PSD Application for Lehigh Mason City, 9/02 . 11 Assessment of Control Technology Options for BART
- Eligible Sources, March 2005 .48

perc ent. 12 We evaluated three control options using three levels of uncontrolled SO 2 emissions: low, moderate and high uncontrolled SO 2 emissions. For examples of kilns with low uncontrolled sulfur emissions, we considered kilns operating in the S tate of Florida. Low uncontrolled sulfur emissions are typical of preheater/precalciner kilns operating in Florida due to the very low amounts of sulfur in most of the available limestone. 13 While making a determination that SO 2 emissions of 0.20 lb/ton of clinke r is BACT, Florida S tate officials expect actual emission levels of 0.01 to 0.05 lb/ton of clinker as a result of the use of these low sulfur raw materials and self scrubbing of fuel SO 2 by finely divided lime in the kiln and calciner. 14 As noted above, h igh uncontrolled SO 2 emissions can occur when pyritic sulfur is present in the raw materials and SO 2 emissions are left uncontrolled. Where such cases have occurred, add
- on controls have been used to reduce SO 2 emissions. Uncontrolled SO 2 emissions of abo ut 5,000 tpy were reported from a preheater/precalciner kiln where a wet scrubber was recently

12 Summary of Cement Kiln Wet Scrubber and Lime Injection Design and Performance Data, May 2, 2008 . 13 Technical Evaluation, Preliminary Determination, Draft BACT Determination, Sumter Cement Company. Florida Department of Environmental Protection, December 21, 2005 . 14 Technical Evaluation, Preliminary Determination, Draft BACT Determination, Sumter Cement Company. Florida Department of Environmental Protection, Dec ember 21, 2005 .49

being added. 15 At a reported production capacity of 800 ,000 tpy 16 , uncontrolled SO 2 emissions would be about 13 lb/ton of clinker. This is considered representat ive of a high uncontrolled SO 2 emission level. A moderate uncontrolled SO 2 emission rate of 1.3 lb/ton of clinker was selected and was based on the average of 18 data points for tested NSPS facilities. 17 All of the SO 2 emission levels discussed above are based on long term average performance, typically 30 days. New cement kilns with SO 2 emission limits typically have continuous SO 2 monitors. In reviewing CEM data we noted that the averaging period affects the achievable SO 2 emission level. Longer averaging periods result in lower average SO 2 levels (since variability tends to be averaged out with multiple measurements over time ) . The first control option we considered was no additional control of SO 2 other than the inherent control achieved b y the kiln and the raw mill. State BACT determinations usually identify inherent SO 2 removal as BACT (reflecting that most of these kilns are located in areas with low sulfur raw materials).

15 PSD Application for Lehigh Mason City, 9/02 . 16 PCA, U.S. and Canadian Portland Cement Industry, Plant Information Summary, December 31, 2006 . 17 Memorandum, E. Heath, RTI, to J. Wood, EPA:OAQPS:ESD:MICG, April 9, 1996, Summary of impacts o f control options on model kilns and clinker coolers. Item no. II - B - 67, Docket no. A
- 92
- 53 .50

Although many kilns have low sulfur emissions, the obvious defi ciency of this option is that some kilns would have moderate or high uncontrolled emissions of SO 2 , due to the presence of pyritic sulfur in their raw materials, which emissions would be readily controllable with air pollution control equipment which in fa ct is usually required in such instances. The second option considered was 1.33 lb/ton of clinker based on a recent BACT determination level for a kiln where uncontrolled SO 2 emission levels were sufficiently high that an alkaline wet scrubber was install ed to reduce SO 2 emissions. This option, and the additional numerical limits discussed below are based on continuous compliance with a 30
- day rolling average as measured using an SO 2 continuous emissions monitor. The third option of 0.4 lb/ton of clinker represents the performance of a lime injection system applied to a kiln with a moderate level of sulfur in its raw materials. The fourth level evaluated was 0.2 lb/ton of clinker which was based on the lowest uncontrolled SO 2 permit levels from recent BACT determinations, and represents a level where moderate and high sulfur kilns will require the use of a wet scrubber for SO 2 control. Several kilns in Florida are permitted at this level where very small amounts of sulfur are present in the raw materials . We are proposing a limit for new kilns of 1.33 lb/ton of clinker, or alternatively, a 90 percent SO 2 emissions reduction51

measured across the control device, such as an alkaline scrubber. 18 The alternative of 90 percent reduction is to account of situation where the sulfur conten t of the raw mat e rials is so high that, even w ith the most efficient SO 2 control, a kiln cannot meet the 1.33 lb/ton of clinker emissions limit. Design and performance data indicate the 90 percent control is continuously a chievable for a well des i gned and operated wet scrubber. 19 Compliance with the 90 percent reduction would be determined by continuously monitoring SO 2 a t the control device inlet and outlet . Continuous monitoring of SO 2 at the inlet and outlet is a positi ve demonstration that the standard is being continuously met. We estimate that r educing high uncontrolled SO 2 emissions to a level of 1.33 lb/ton of clinker results in a $ 28 million capital cost , an annual cost of $ 5 million , and a cost effectiveness of less than $ 1 ,000 per ton of SO 2 removal. 20 We consider this level of cost effectiveness to be reasonable as it falls at the lower end of the range of reference cost effectiveness for SO 2 emission controls considered to be “high ly cost effective” (for purposes of CAA section 110(a)(2)(D) in the

18 Section 111(b) specifically indicates that standards may be expressed as numerical limits or as percent reductions. 19 Summary of Cement Kiln Wet Scrubber and Lime Injection Design and Performance Data, May 29, 2008 20 Summary of Environmental and Cost Impacts of Proposed Revisions to Portland Cement New Source Performance Standards, May 29, 2008 .52

CAIR rule ) . See 70 FR 25204 (May 12, 2005). Under this option, only kilns with moderate or high uncontrolled SO 2 emission levels would likely need to install add
- on controls. There are

currently only five kilns out of 178 kilns in the U.S. where uncontrolled SO 2 emission levels required the addition of a wet scrubber. We estimate conservatively in costing this option that over the 5
- year period following promulgation of these amendments, one out of every five new kilns would have uncontrolled SO 2 emission levels sufficient to warrant the use of a scrubber to reduce SO 2 emissions to the level of 1.33 lb/ton of clinker or, alternatively, demonstrate a 90 percent reduction in SO 2 emissions. We rejected Options 3 and 4 because they would have resulted in cement kilns with moderate uncontrolled SO 2 emission levels having to apply add
- on controls, either dry lime sprayers at a cost of approximately $ 6,3 00 per ton of SO 2 reduction under Opt ion 3 or a wet scrubber at a cost of approximately $ 6,7 00 per ton of SO 2 reduction under Option 4. 21 Not only do these options result in a higher cost per ton of SO 2 reduction than Option 2, but Options 3 and 4 would not be likely to achieve any significant additional SO 2 emission reductions over Option 2 for kilns emitting high uncontrolled levels of SO 2 because Option 2 already represents a 90 percent emission reduction control for high sulfur raw materials.53

The proposed SO 2 emissions limit of 1.33 lb/ton of clinker should not result in any non
- air environmental impacts. Liquid waste f rom the scrubber can be dewatered and returned to the process. The resulting solids (gypsum) can be added to the clinker to produce cement. In cases where lime injection is used, the lime solids will be mixed in with the collected PM and returned to the process. There will be an energy impact as a result of increased electrical requirements to operate the control devi c es and, in the case of a wet scrubber, incre ased energy to operate the induced draft fans to overcome the wet scrubber pressure drop. These increases in energy use will be minimal compared to total kiln electrical energy demands. Currently only five kilns , or less than 3 percent of all kilns , ar e using wet scrubbers to control SO 2 emissions. Since most new kilns will undoubtedly be located at existing cement plants where the amount of sulfur in limestone raw materials currently being used is low resulting in low uncontrolled SO 2 emissions, they will likely achieve the proposed standard without the need for add
- on air pollution controls. For the few new greenfield kilns that will be built, the presence or absence of pyritic sulfur limestone , which can result in high uncontrolled SO 2 emissions, can be factored into any site selection decisions. The effect of the proposed limit will ensure that the typical performance of BDT control systems today54

is achieved for future affected kilns in those situations where the presence of pyritic s ulfur raw materials would otherwise result in high uncontrolled SO 2 emissions. 5. VOC/CO We are not proposing to establish limits for CO or volatile organic compound (VOC) emissions from cement kilns. VOC emissions from new cement kilns will mainly resu lt from organics in the raw materials. Organic constituents in the raw materials can be driven off in the kiln preheater prior to reaching temperature zone that would result in combustion. All n ew cement kilns are currently subject to a continuous 20 p ar ts per million volume (ppmv) total hydrocarbon (THC) emissions limit
- THC serving as a surrogate for non
- dioxin HAP
-- by the Portland Cement NESHAP. See 71 FR 76530, December 20, 2006. Because most of the THC are also VOC, the THC limit also limits VOC , and serves as the baseline for the NSPS analysis. This limit is based on the best performance of the regenerative thermal oxidizer add
- on control, which is the most effective VOC emission control available for this source category . Therefore we determi ned that no additional regulation of VOC emissions is feasible. EPA is currently reconsidering the Portland Cement NESHAP THC limit pursuant to section 307(d)(7)(B) of the CAA. See 71 FR 76553, December 20, 2008. However, based on the information55

currently available to us, there is no reason to assume that the THC limit after reconsideration will not still represent BDT for this source category. Emissions of CO can come from two sources, unburned fuel from the precalciner and CO evolved from the raw materials by the same mechanism as the THC emissions. Unburned fuel represents an economic loss to the facility. Therefore, new precalciners are designed to combust fuel as efficiently as possible, and CO emissions from fuel combustion are minimized,

r egardless of any potential emission limit. Emissions of CO evolved from raw materials can be significant if there are substantial levels of organics in the raw material. The only control technology identified to reduce CO emissions is a regenerative thermal oxidizer (RTO) (which also would concurrently reduce any VOC emissions , as just discussed ). However, as is the case for VOC, facilities with moderate or high levels of organic materials in the feed would emit THC at levels high enough that THC control would be required under the Portland Cement NESHAP. Therefore, the THC limit in the Portland Cement NESHAP also serves as the baseline of the CO analysis. As previously noted, the THC limit is based on the best performance of the regenerative thermal oxi dizer add
- on control, which is also the most effective CO emission control available for this source category . Therefore we56

determined that no additional regulation of CO emissions is feasible.

We also noted that in no cases had add
- on controls for CO (or VOC) been required as BACT under new source review. B. How is EPA proposing to amend the testing requirements? Subpart F currently requires PCP to conduct an initial performance test to demonstrate compliance with the PM emission limits. There is no requirement for repeat performance tests. Under the proposed amendments, new kilns would be required to conduct repeat performance tests every 5 years following the initial performance test, as is done for compliance with the MACT standard for PM for kilns at major sources (64 FR 31903, June 14, 1999) , and existing kilns subject to the NSPS would be required t o begin testing every five years . We are also requiring existing kilns subject to the NSPS to begin testing every 5 years. We do not see this as a substantive change becau s e the majority of kiln s already have a similar testing requirement under the Portland Cement NESHAP , 40 CFR 63 , subpart LLL. There are no NO X or SO 2 compliance testing requirements ; compliance is based on the use of a continuous emissions monitor (see below ). C . How is EPA proposing to amend the monitoring requirements?57

We are proposing the use of a bag leak detection (BLD) system on fabric filters used to control PM emissions from new kilns and clinker coolers. We believe the use of BLD systems would be more effective in ensuring ongoing compliance with the PM limit than the current stack opacity limit in the current NSPS . Consequently, affected facilities under this rule would not be subject to an opacity standard to monitor compliance with the proposed PM standard. Bag leak detect ion systems must be installed and operated according to the proposed §60.6 3 (f) requirements. If a new facility installs an ESP we are proposing to r equire use of an ESP predictive model to determine compliance. As with use of a bag leak detector, no opacity standard would apply. As an option, we are allowing a facility to install a PM CEMS in lieu of using a BDL or using an ESP predictive model . If a facility elects this option, the PM CEMS should be installed and operated in accordance with proposed § 60.63( g ) . For existing sources that are current ly subject to the NSPS, we are also providing an option to install a BLD to

mo nitor complianc e with the PM standard. We are also providing an option for any source subject to the NSPS PM limit to install a PM continuous monitoring system (PM CEMS). For any source58

that installs a BLD or PM CEMS, the opacity standard would no longer apply. 21
For a ll emission sources other than the kiln and clinker cooler that are subject to the 10 percent opacity standard, we are requiring that they meet the monitoring requirements for these sources containe d in the Portland Cement NESHAP, 40 CFR part 63 , subpart L LL. Under the proposed amendments, compliance with the emission limits for NO X and SO 2 would be determined using continuous emissions monitoring systems (CEMS). This requirement is consistent with recent State permit requirements that require continuou s monitoring for NO X and SO 2 . Requirements for the installation, operation, and calibration of each CEM , including minimum data requirements are specified in proposed §60.63(k) and (l). Kilns meeting the alternative SO 2 emission limit of 90 percent reduction would also be required to continuously monitor SO 2 emissions at the scrubber inlet. T he cost impacts shown in the preamble include all monitoring costs. 21 D . Why are we not proposing to revise the o ther emission limits in the NSPS not being revised?

21 Note that we are not proposing to change the requirements in paragraph § 60.63(b). These requirements are in the proposed § 60.63(b)(1)(i) and are reprinted as a convenience to the reader.59

The proposed revisions to the emission limits cover only the cement kiln and clinker cooler. The current NSPS also limits emissions from materials handling operations. These operations are potential emitters of PM, but do not emit other criteria pollutants. Emissions from materials handling points are typically fugitive emissions , though in some cases emissions are captured and exhausted through a stack. The current opacity limit for these operations is 10 perce nt. We considered the possibility of setting a lower limit, but we do not have data to indicate that a lower limit is achievable or whether costs associated with a lower opacity limit are reasonable. We currently have no data to indicate that the current level is not what is being achieved in practice. We are requesting comment and any available data addressing capability, if any, to further reduce opacity and, if lower limits are feasible, what the associated costs would be.
E . What other changes are being proposed? As previously noted , cement kilns are potentially subject to both the NSPS and the Portland Cement NESHAP (40 CFR part 63, subpart LLL) . In § 63.1356 of subpart LLL , we exempt any source subject to that subpart fr om applicable standards under the NSPS and the Metallic Minerals Processing NSPS (subpart OOO). That60

language was appropriate because the NSPS only regulated PM, and the PM limits in the NSPS and NESHAP were identical. This is no longer the case. As a r esult, we are proposing to insert language in both the NSPS and the NESHAP to state that when there are emissions standards for a specific pollutant that apply to an affected sources in both the NESHAP and the NSPS, the source should comply with the most s tringent limit, and is not subject to the less stringent limit. F . What is EPA’s s ector -b ased approach and h ow is it r elevant to this rulemaking ? In the National Academy of Science’s 2004 report, “Air Quality Management in the United States,” the Natio nal Research Council (NRC) recommended to EPA that standard setting, planning and control strategy development be based on integrated assessments that consider multiple pollutants and those integrated assessments be conducted in a comprehensive and coordin ated manner. With these recommendations, EPA began to move towards establishing multi
-pollutant and sector
- based approaches to managing emissions and air quality. These sector
based approaches essentially expand technical analyses on costs and benefits o f particular technologies, and interactions of rules that regulate sources within facilities. The benefit of multi
-pollutant and sector
-based analyses and approaches include the ability to identify optimum strategies, considering61

feasibility, costs, and b enefits across all pollutant types

– criteria, toxics and others
-- while streamlining administrative and compliance complexities and reducing conflicting and redundant requirements. With these recommendations, EPA’s intent is to move toward multi
- pollutant and sector
-based approaches in managing emissions and air quality. One of the many ways we can address sector
-based approaches is by reviewing multiple regulatory programs together when ever possible. This approach should result in added certainty and easier implementation of control strategies for the sector under consideration. Multiple regulatory requirements currently apply to the cement industry sector. In an effort to facilitate sector
-based approaches for the cement industry, EPA analyzed the interactions between the NSPS under review here and oth er regulatory requirements for p ortland cement facilities currently under review and/or reconsideration. The requirements analyzed would affect HAP and/or criteria pollutant emissions from cement kiln s and comprise the NSPS, NESHAP reconsideration for mercury ( Hg ) and THC, area source NESHAP, and NESHAP technology review and residual risk. The results of our analyses are described below. The first interaction is the relationship between the NSPS VOC - C O standard and the NESHAP THC standard discussed above. As62

explained there, the 20 ppmv THC limit for new sources in the NESHAP will also control VOC and CO to the limit of technical feasibility. Another interaction relates to the more stringent PM emission limit under NSPS and the PM emissions limit for new sources under the NESHAP. We are proposing a limit of 0.086 lb/ton of clinker as compared to the current new source PM limit in the NESHAP of 0.5 lb/ton of clinker (0.3 lb/ton of feed). This results in a situation where the MACT PM emission s limit for new sources is higher (less stringent) than the NSPS emissions limit. As a result, EPA will consider whether or not we should address the PM st andard in the NESHAP as part of the ongoing reconsideration. At a minimum, and as just explained,

we are proposing to place language in both the NESHAP and the NSPS making it clear that if a particular source has two different requirements for the same po llutant, they should comply with the most stringent emission limit, and are not subject to the less stringent limit. The proposed NSPS PM limit also has implications for the PM limit for area sources under the NESHAP. We currently have a requirement to ex tend the PM limit in the NESHAP to kilns located at area sources in order to meet our requirements to subject to regulation area sources accounting for 90 percent of the emissions of the HAP identified in our Urban Air Toxics63

Strategy. 22 Having a different limit for kilns under NESHAP and NSPS has implications for the appropriate PM level to apply to new kilns located at area sources under the NESHAP. In addition to the current regulatory efforts, we are required under CAA section 112(f) to evaluate the residual risk for toxic air pollutants emitted by this source category and to perform a technology review for this source category under section 112(d)(6). As we consider any changes in the PM limits under MACT and generally available control technology ( GACT ) , we will also consider the implication these may have in developing future requirements under residual risk and technology review. Another interaction with implications for the co
- control of mercury is the pr oposed SO 2 standard under the NSPS. As described above, the proposed standard for SO 2 control is 1.33 lb/ton of clinker, or in the alternative , demonstration of a 90 percent SO 2 emissions reduction measured across the control device, such as an alkaline s crubber. Under the NESHAP reconsideration , EPA may amend the MACT standard for Hg for new and existing source s . A facility that is considering adding a new source that may be subject to SO 2 add
- on control requirements will have to consider the interactio n of their choice of SO 2 and mercury controls. For example, a facility that determines a

22 Memo from K. Barnett, EPA to Sharon Nizch, EPA. Revision of Portland Cement NESHAP PM limits for Area Sources. May 2008.64

moderate level of SO 2 reduction would meet the SO 2 emission limit (i.e. 70 percent or less) might consider using a lime injection system because it is lower cost. However, if the same facility would have to use some type of add
- on control to meet the current new source Hg emission limit of 41 micrograms per dry standard cubic meter ( ug/dscm ) , then the cheapest overall alternative might be to use a wet scrubber for con trol of both SO 2 and mercury . In general, we will ensure that our rulemaking recognizes that where monitoring is required, methods and reporting requirements should be consistent in the NSPS and NESHAP where the pollutants and emission sources have similar characteristics. As an example, we are proposing to add a requirement to the NSPS that a PM emissions compliance test on the kiln and clinker cooler be done every five years, as is currently required in the Portland Cement NESHAP for major

sources , and we are incorporating the Portland Cement NESHAP monitoring requirements for sources other than kilns and clinker coolers into the NSPS. In order to analyze sector -based approaches for the U.S. cement industry, EPA is developing a dynamic techno
- economic model of this industry. Using this model, EPA will be able to analyze emission reduction strategies for multiple pollutants, while taking into account plant
- level economic and technical65

factors such as the type of kiln, associated capac ity, location, cost of production, applicable controls and costs. For each of the emission reduction strategies under consideration, the model will be able to provide information on optimal (least cost) industry operation and cost
- effective controls, to meet the demand for cement and the emission reduction requirements over the time period of interest. More information on the model can be found in the rulemaking docket. We welcome comments and suggestions related to the potential uses of our techno
- economic model as well in the interaction of this proposed NSPS and other regulatory requirements in the context of the sector -based considerations described above. G . How is EPA addressing g reenhouse gas emissions from the p ortland c ement i ndustry? While CAA section 111(b)(1)(B) permits EPA, under appropriate circumstances, to add new standards of performance for additional pollutants concurrent with the 8
- year review of existing standards, we are not at this time proposing performance standards for greenhouse gases (GHG) from cement kilns. Rather, for the reasons recently explained in declining to set GHG standards from p etroleum refineries , we believe that it is appropriate in the first instance to consider issues related to the regulation of GHGs under the CAA through the66

advance notice of proposed rulemaking announced by the Administrator on March 27, 2008. V. Summary of Cost, Environmental, Energy, and Economic Impacts of the Proposed Amend ments to Subpart F In setting standards, the CAA requires us to consider alternative emission control approaches, taking into account the estimated costs as well as impacts on energy, solid waste, and other effects. We request comment on whether we have i dentified the appropriate alternatives and whether the proposed standards adequately take into consideration the incremental effects in terms of emission reductions, energy, and other effects. We will consider the available information in developing the f inal rule. We are presenting estimates of the impacts for the proposed amendments to 40 CFR part 60, subpart F that change the performance standards. The cost, environmental, and economic impacts presented in this section are expressed as incremental diff erences between the impacts of PCP complying with the proposed subpart F revisions and the baseline . The impacts are presented for new PCP affected facilities that commence construction, reconstruction, or modification over the 5 years following promulgat ion of the revised NSPS. The analyses and the documents referenced below can be found in Docket ID No. EPA- HQ - OAR- 2007
- 0877.67

In order to determine the incremental impacts of this proposed rule, we first estimated the number of new kilns that will begin op eration over the 5
- year period following promulgation of the final amendments. We estimate that 20 new kilns will be subject to the proposed amendments by the end of the 5th year after promulgation of the amendments representing approximately 24 million tpy of clinker capacity. 1 A. What are the air quality impacts ? The proposed PM emission limit represents a lowering of the PM emission limit from 0.5 lb/ton of clinker production to 0.086 lb/ton of clinker . Out review of the performance of recently installed fabric filters indicates that typical new kiln PM emissions are approximately 0.16 lb/ton of clinker rather th an 0.5 lb/ton of clinker , the current NSPS limit. We estimate that the PM reduction per ki ln as a result of the proposed PM emissions limits will be 44 tpy based on our 1.2 million tpy model kiln, and 888 tpy nationally in the fifth year after promulgation of the standard. This represents a national reduction in PM fine emissions of approximately 400 tpy. Under the proposed limit for NO X , we have estimated that the emission reduction for our 1.2 million tpy model kiln would be 600 tpy . The projected national emissions reduction 5 years

a fter promulgation of the final standards will be 12,000 tpy.68

Under the proposed limit for SO 2 , we estimated that a new kiln processing raw materials containing high levels of sulfur would be required to install an alkaline scrubber in order to comply with the proposed limit. For our model kiln , emissions of SO 2 would be reduced by 7,410 tpy where high sulfur raw materials are being processed . We estimated that during the 5 years following promulgation of the final standard, four new kilns are expected to be required to install an alkaline scrubber to meet the proposed SO 2 emission limit. The national emissions reduction 5 years after promulgation of the final standards will be 29,640 tpy. This national emissions reduction may be less than estimated above if some kilns that would have to control SO 2 as a result of this proposed rule are required to apply wet scrubbers as a result of the current mercury emission requirements in the P ortlan d Cement NESHAP (see further discussion in the cost impacts section). Under the proposed standards, new monitoring requirements would be added. Bag leak detectors would be required on fabric filters used to control new kilns and clinker coolers, and NOX and SO2 CEMS would be installed to monitor compliance of new kilns wit h the new NOX and SO 2 emission limits. As a result of the shortened duration of excess emissions with the improved monitoring requirements we estimate potential excess emission reductions of 12.38 tpy for PM, 5.57 tpy for PM2.5, 108 tpy for69

NOX, and 9.36 tpy for SO 2 . For further detail on the methodology of these estimates, see Docket ID no. EPA
- HQ - OAR- 2007
- 0877. B. What are the water quality impacts? No water quality impacts for the proposed amendments are anticipated. The requirements for new sources that might result in the use of alkaline scrubber to control SO 2 will produce a scrubber slurry liquid waste stream. However, as noted above, we assume the scrubber slurry produced will be dewatered and added back into the cement
-making process as gypsum . Water from the dewatering process will be recycled back to the scrubber. C. What are the solid waste impacts? The potential for solid waste impacts are associated with greater PM control for new kilns and solids resulting from solids in scrubber slurr y water. Little or no solid waste is expected from the generation of scrubber slurry because (as just explained for the scrubber water) it is assumed that the slurry will be dewatered and the solids added back to the process as gypsum to make cement. The PM captured in the kiln fabric filter (cement kiln dust) is essentially re
- captured raw material and is recycled back to the kiln. Where equipped with an alkali bypass, captured PM is typically disposed of as solid waste. An alkali bypass is not require d on all kilns. Where one is present, the amount of solid waste generated from the alkali bypass is minimal, usually about 1 percent of total70

cement kiln dust captured in control devices, because the bypass gas stream is a small percentage of total kiln e xhaust gas flow and the bypass gas stream does not contact the feed stream in the raw mill. 1 D . What are the secondary impacts? Indirect or secondary air quality impacts include impacts that would result from the increased electricity usage associated with the operation of control devices (e.g., increased secondary emissions of criteria pollutants from power plants) as well as water quality and solid waste impacts that would occur as a result of t hese proposed revisions ( which are minimal, as just discu ssed) . We estimate that t hese proposed revisions would increase emissions of pollutants from utility boilers that supply electricity to the portland cement facilities. We estimate increase energy demand associated with the installation of scrubbers to co ntrol SO 2 emissions. These increases are estimated to be 15 tpy of NO X , 8 tpy of CO, 26 tpy of SO 2 and about 1 tpy of PM at the end of the 5th year after promulgation. The increase in electricity usage for the pumps used in the SNCR system to de liver reagent to the kiln are negligible. E . What are the energy impacts ? Energy impacts consist of the electricity needed to operate control devices and other equipment that would likely be71

utilized to comply with the proposed standards. This proposal

w ill likely result in the addition of alkaline scrubbers to certain kilns to reduce SO 2 emissions. We estimate the additional national electrical demand to be 6.9 million kWhr per year by the end of the 5 th year. F . What are the cost impacts ? Under the proposed amendments, the cost for new kilns are based on the use of NOX and SO 2 continuous emissions monitors, bag leak detectors, SNCR for NO X control, and membrane bags in fabric filters . We estimate that four of the twenty new kilns will also need to install a wet scrubber to meet the proposed SO 2 emissions limits (based on our estimates of where the plants will be located and the sulfur content of the limestone in those areas) . The total capital cost per kiln is estimated to be $3, 9 00,000 ki lns that are not required to install wet scrubbers and $ 32,000 ,000 for kilns that are required to install wet scrubbers. The cumulative capital cost in the fifth year is estimated to be $ 1 90 ,000,000 . The estimated total annualized cost per new kiln will be $1,500,000 for kiln s that do not install wet scrubbers and $ 6,400,000 for those that do install wet scrubbers . National annualized costs will be $ 50,0 00,000 . The national costs shown above are cons idered to be a conservative estimate because they do not include the potential impact of requirements f or new sources in the Portland C ement72

NESHAP, which limits mercury emission form new kilns to 41 micrograms per dry standard cubic mete r (See 71 FR 76518 ) . In this final rule we estimated that seven of the new cement kilns expected in the next five years will need to install a wet scrubber to meet the mercury emissions limit, and we assessed the costs of those scrubbers as part of our analysis of the NESHAP. There are no data to positively determine if the four cement kilns we project here as needing wet scrubbers to meet the proposed SO 2 emissions limit are among the seven kilns we projected as needing wet scrubbers to meet the mercury limit in the NESHAP. However, the available mercury test data for cement kilns that currently have wet scrubbers indicate that they all five of these kilns, if they were new sources, would have to apply mercury controls to meet the current mercury limit in the Portland Cement NESHAP. These kilns are also located in areas where the raw materials sulfur content is high enough that, if they were new sources, they would also have to apply controls too meet the proposed NSPS SO 2 emissions limit. Based on this, we believe it is reasonable to assume there will be some

overlap, and the national costs for the proposed NSPS, emissions reductions, and energy impacts will be reduced. G. What are the economic impacts ? This proposal affects certain new and reconstructed/ modified affected facilities found at PCP as defined earlier in73

this preamble. We performed an economic impact analysis that estimates ch anges in prices and output for p ortland cement manufacturing nationally using the annual compliance cos ts estimated for this proposal. All estimates are for the fifth year after promulgation since this is the year for which the compliance cost impacts are estimated. Existing data on planned capacity expansions suggests 20 new kilns will be constructed in t he next 5 years. 1 EPA estimates up to four of these kilns may use high sulfur raw materials while the remaining 16 will likely use moderate or low sulfur raw materials. The engineering cost analysis suggests new kiln using high sulfur raw materials coul d potentially spend up to $6.4 million dollars per year to meet the selected control options for NO X , SO2, and PM (see T able 2 of this preamble ). The average cost per ton of capacity is approximately $5. In contrast, new kilns using moderate or low sulfu r raw materials could potentially spend $1.5 million dollars per year. The average cost per ton of capacity is approximately $1. Table 2. Model Plant Costs (Clinker Capacity =1.1 million metric tons per year)

Kiln t ype Number of k ilns (5
- year p eriod) Total

annualized c osts ($ million) New s ource

unit c ost ($/metric ton of capacity)74

High s ulfur r aw materials 4 $6.4 $5 Moderate or l ow s ulfur r aw materials 16 $1.5 $1

The USGS reports that the real price of cement per metric ton (2005 dollars) has typically ranged between $75 and $100 since 1990. For high sulfur raw material kilns, this implies a sales test ratio between 5 to 7 percent. For moderate/low sulfur raw mat erial kilns, the sales test ratio is one to two percent. From 2000 to 2006, the Portland Cement Association (PCA, 2007) reports that the average operating profit rates for the industry ranged from 17 to 21 percent. If this profit data is representative o f operating profit rates for new kilns, new kilns using high sulfur content raw materials could potentially have significantly reduce d operating profit s. As a result, companies may have the incentive to look for less expensive alternatives to meet the SO2 emission standards (e.g. lower sulfur content materials or technologies other than wet scrubbers). Although anecdotal evidence suggests these opportuni ties exist, EPA does not currently have sufficient information to do a formal evaluation of these alternatives. We also considered potential market
- level changes in prices and consumption for multiple geographic markets anticipating entry of new kilns. The sales tests suggest long run cement price changes could range from one to seven percent, depending75

on the actual baseline market cement price and the type of kiln entering the market. Applying EPA’s econometric estimate of the cement demand elasticity (

– 0.88) to these price changes, cement consumption could potentially fall between one to six percent. For more information, please refer to the economic impact analysis report that is in the docket for this proposed rule. VI. Statutory and Executive Order Reviews A. Executive Order 12866: Regulatory Planning and Review Under Executive Order 12866 (58 FR 51735, October 4, 1993), this action is a “significant regulatory action” because it may raise novel legal or policy issues. Accordingly, EPA submitte d this action to OMB for review under Executive Order 12866, and any changes made in response to OMB recommendations have been documented in the docket for this action. B. Paperwork Reduction Act The information requirements in the proposed amendments have been submitted for approval to the Office of Management and Budget (OMB) under the Paperwork Reduction Act, 44 U.S.C. 3501 et seq . The Information Collection Request (ICR) document prepared by EPA has been assigned EPA ICR number [XXXX.XX}. The proposed amendments to the NSPS for portland cement plants apply to affected facilities constructed, modified, or reconstructed after [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER]. The owner or operator of a new kiln would be76

required to keep daily records of clinker production, conduct an initial performance test and repeat performance tests (PM), install and operate bag leak detection systems or PM CEMS for fabric filters used to meet the PM emission limit, and operate NO x and SO 2 CEMS. These requirements are based on the recordkeeping and reporting requirements in the NSPS General Provisions (40 CFR part 60, subpart A) which are mandatory for all operators subject to new source performance standards. These recordkeeping and reporting requirement s are specifically authorized by section 114 of the CAA (42 U.S.C. 7414). All information submitted to EPA pursuant to the recordkeeping and reporting requirements for which a claim of confidentiality is made is safeguarded according to EPA policies set f orth in 40 CFR part 2, subpart B. The annual burden for this information collection averaged over the first 3 years of this ICR is estimated to total 4,428 labor
- hours per year at a cost of $ 416,179 per year. The annualized capital costs are estimated at $5 9,035 per year and operation and maintenance costs are estimated at $ 73,852 per year . Burden is defined at 5 CFR 1320.3(b). An agency may not conduct or sponsor, and a person is not required to respond to a collection of information unless it displays a currently valid OMB control number. The OMB control numbers for EPA’s regulations are listed in 40 CFR part 9.77

To comment on the Agency’s need for this information, the accuracy of the provided burden estimates, and any suggested methods for minimizing respondent burden, EPA has established a public docket for this rule, which includes this ICR, under Docket ID number EPA
- HQ - OAR- 2007
- 0877. Submit any comments related to the ICR for this proposed rule to EPA and OMB. See ADDRESSES section at the beginning of this document for where to submit comments to EPA. Send comments to OMB at the Office of Information and Regulatory Affairs, Office of Management and Budget, 725 17 th Street, NW, Washington, DC 20503, Attention: Desk Office for EPA. Since OMB is required to make a decision concerning the ICR between 30 and 60 days after [INSERT DATE OF PUBLICATION IN THE FEDERAL REGISTER], a comment to OMB is best assured of having its full effect if OMB receives it by [INSERT DATE 30 DAYS AFTE R PUBLICATION IN THE FEDERAL REGISTER]. The final rule will respond to any OMB or public comments on the information collection requirements contained in this proposal. C. Regulatory Flexibility Act The Regulatory Flexibility Act (RFA) generally require s an agency to prepare a regulatory flexibility analysis of any rule subject to notice and comment rulemaking requirements under the Administrative Procedure Act or any other statute unless the agency certifies that the rule will not have a significant

eco nomic impact on a substantial number of small entities.78

Small entities include small businesses, small organizations, and small governmental jurisdictions. For purposes of assessing the impact of this rule on small entities, small entity is defined as: (1) a small business whose parent company has no more than 750 employees (as defined by Small Business Administration (SBA) size standards); (2) a small governmental jurisdiction that is a government of a city, county, town, school district, or special dis trict with a population of less than 50,000; and (3) a small organization that is any not
- for
-profit enterprise which is independently owned and operated and is not dominant in its field. After considering the economic impact of this p roposed rule on small entities, I certify that this action will not have a significant economic impact on a substantial number of small entities. We estimate that up to 7 of the 44 existing PCP are small entities which would not incur any impacts under these proposed amendmen ts unless an affected facility is constructed, modified, or reconstructed. Based on our economic analysis, 20 new kilns may be constructed during the next five years. One of these kilns may be operated by a PCP that is classified as small entities according to the SBA small business size standards. Of these 20 kilns, this small entity is expected to incur an annualized compliance cost of between 1.0 and 2.0 percent of sales to comply with the proposed action.79

Although this proposed rule will not have a significant economic impact on a substantial number of small entities, EPA nonetheless has tried to reduce the impact of this rule on small entities by selection proposed emission level based on highly cost effective controls and specifying monitoring requirements that are the minimum to insure compliance. In the case where there are overlapping standards between this NSPS and the Portland Cement NESHAP, we have exempted source f rom the least stringent requirement thereby eliminated overlapping monitoring , testing and reporting requirements by proposing that the source comply with only the more stringent of the standards . We continue to be interested in the potential impacts of the proposed rule on small entities and welcome comments on issues related to such impacts. D. Unfunded Mandates Reform Act Title II of the Unfunded Mandates Reform Act (UMRA) of 1995, Public Law 104
- 4, establishes requirements for Federal agencies to assess the effects of their regulatory actions on State, local, and tribal governments and the private sector. Under section 202 of the UMRA, EPA generally must prepare a written statement, including a cost
- benefit analysis, for proposed and final rules with “Federal mandates” that may result in expenditures by State, local, and triba l governments, in the aggregate, or to the private sector, of $100 million or more in80

any one year. Before promulgating an EPA rule for which a written statement is needed, section 205 of the UMRA generally requires EPA to identify and consider a reasonab le number of regulatory alternatives and adopt the least costly, most cost
effective, or least burdensome alternative that achieves the objectives of the rule. The provisions of section 205 do not apply when they are inconsistent with applicable law. Mor eover, section 205 allows EPA to adopt an alternative other than the least costly, most cost
- effective, or least burdensome alternative if the Administrator publishes with the final rule an explanation why that alternative was not adopted. Before EPA establishes any regulatory requirements that may significantly or uniquely affect small governments, including tribal governments, it must have developed under section 203 of the UMRA a small government agency plan. The plan must provide for notifying potenti ally affected small governments, enabling officials of affected small governments to have meaningful and timely input in the development of EPA regulatory proposals with significant Federal intergovernmental mandates, and informing, educating, and advising small governments on compliance with the regulatory requirements. EPA has determined that this rule does not contain a Federal mandate that may result in expenditures of $100 million or more for State, local, and tribal governments, in the81

aggregate, or t he private sector in any one year. As discussed earlier in this preamble, the estimated expenditures for the private sector in the fifth year after promulgation are $ 50 million. Thus, this rule is not subject to the requirements of section 202 and 205 of the UMRA. In addition, EPA has determined that this proposed action contains no regulatory requirements that might significantly or uniquely affect small governments. This rule contains no requirements that apply to such governments, imposes no obligati ons upon them, and would not result in expenditures by them of $100 million or more in any one year or any disproportionate impacts on them. Therefore, this proposed action is not subject to the requirements of section 203 of the UMRA. E. Executive Order 13132: Federalism Executive Order 13132 (64 FR 43255, August 10, 1999), requires EPA to develop an accountable process to ensure “meaningful and timely input by State and local officials in the development of regulatory policies that have federalism impl ications.” “Policies that have federalism implications” is defined in the Executive Order to include regulations that have “substantial direct effects on the States, on the relationship between the national government and the States, or on the distributio n of power and responsibilities among the various levels of government.”82

This proposed rule does not have federalism implications. It will not have substantial direct effects on the States, on the relationship between the national government and the State s, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132. None of the affected facilities are owned or operated by State governments. Thus, Executive Order 13132 does not apply to this proposed rule . In the spirit of Executive Order 13132, and consistent with EPA policy to promote communications between EPA and State and local governments, EPA specifically solicits comment on this proposed action from State and local officials. F . Executive Order 13175: Consultation and Coordination with Indian Tribal Governments Executive Order 13175, entitled “Consultation and Coordination with Indian Tribal Governments” (65 FR 67249, November 9, 2000), requires EPA to develop an accountable p rocess to ensure "meaningful and timely input by tribal officials in the development of regulatory policies that have tribal implications." This proposed rule does not have tribal implications, as specified in Executive Order 13175. It will not have subs tantial direct effects on tribal governments, on the relationship between the Federal government and Indian tribes, or on the distribution of power and responsibilities83

between the Federal government and Indian tribes, as specified in Executive Order 13175 . The proposed rule imposes requirements on owners and operators of specified industrial facilities and not tribal governments. Thus, Executive Order 13175 does not apply to this proposed rule. EPA specifically solicits additional comment on this propos ed rule from tribal officials. G. Executive Order 13045: Protection of Children from Environmental Health Risks and Safety Risks EPA interprets Executive Order 13045 as applying to those regulatory actions that concern health or safety risks, such that t he analysis required under section 5
- 501 of the Order has the potential to influence the regulation. This action is not subject to Executive Order 13045 because it is based solely on technology performance. H. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use This rule is not a “significant energy action” as defined in Executive Order 13211, “Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use” (66 FR 28355, May 22, 2001) because it is not likely to have a significant adverse effect on the supply, distribution, or use of energy. Further, we have concluded that this proposed rule is not likely to have any adverse energy effects. This proposal84

will result in the addition of alkaline scrubbers to certain kilns to reduce SO 2 emissions. We estimate the additional electrical demand to be 6.9 million kWhr per year by the end of the 5 th year. I. National Technology Transfer and Advancement Act Section 12(d) of the National Technology Transfer and Advancement Act of 1995 (“NTTAA”), Public Law No. 104
- 113 (15 U.S.C. 272 note) directs EPA to use voluntary consensus standards (VCS) in its regulatory activities unless to do so would be inconsistent with applicable law or otherwise impractical. Voluntary consensus standards are technical standards ( e.g. , materials specifications, test methods, sampling procedures, and business practices) that are developed or adopted by VCS bodies. NTTAA directs EPA to provide Congress, through OMB, explanations when the Agency decides not to use available and applicable VCS. This proposed rulemaking involves technical standards. EPA proposes to use the VCS ASME PTC 19.10
- 1981, “Flue and Exhaust Gas Analyses,” for its manual methods of measuring the content of the exhaust gas. These parts of ASME PTC 19.10
- 1981 are acceptable alternatives to EPA Methods 3B, 6, 6A, 7, and 7C. This standard is available from the American Society of Mechanical Engineers (ASME), Three Park Avenue, New York, NY 10016

– 5990.85

While the Agency has identified 12 VCS as being potentially applicable to this rule, we have decided not to use these VCS in this rulemaking. The use of these VCS would have been impractical because they do not meet the objectives of the standards cited in this rule. See the docket for this rule for the reasons for these determinations. Under 40 CFR 60.13(i) of the NSPS General Provis ions, a source may apply to EPA for permission to use alternative test methods or alternative monitoring requirements in place of any required testing methods, performance specifications, or procedures in the final rule and amendments. EPA welcomes commen ts on this aspect of th is proposed rulemaking and, specifically, invites the public to identify potentially
- applicable voluntary consensus standards and to explain why such standards should be used in this r egulation. J. Executive Order 12898: Federal Ac tions to Address Environmental Justice in Minority Populations and Low
- Income Populations Executive Order 12898 (59 FR 7629 (Feb. 16, 1994)) establishes Federal executive policy on environmental justice. Its main provision directs Federal agencies, to the greatest extent practicable and permitted by law, to make environmental justice part of their mission by identifying and addressing, as appropriate, disproportionately high and adverse human health or86

environmental effects of their programs, policies, and activities on minority populations and low
- income populations in the United States. EPA has determined that the prop osed amendments w ill not have disproportionately high and adverse human health or environmental effects on minority or low
- income populations because they would increase the level of environmental protection for all affected populations without having any disproportionately high and adverse human health or environmental effects on any population, including any minority or low
- income population. These proposed standards would reduceAmendments to Standards of Performance for Portland Cement Plants—

page 87 of 110 emissions of PM, NO X , and SO 2 from all new, reconstructed, or modified affected facilities at PCP, decreasing the amount of such emissions to which all affected populations are exposed. List of Subjects in 40 CFR Part 60 Environmental protection, Administrative practice and procedure, Air pollution control, Incorporation by reference, Intergovernmental relations, Reporting and recordkeeping requirements. List of Subjects in 40 CFR Part 6 3 Environmental protection, Air poll ution control.

Dated:

Stephen L. Johnson, Administrator.88

For the reasons stated in the preamble, title 40, chapter I, of the Code of Federal Regulations is proposed to be amended as follows: PART 60 -- [AMENDED] 1. The authority citation for part 60 continues to read as follows: Authority: 42 U.S.C. 7401, et seq . Subpart A

— [Amended] 2. Section 60.17 is amended by revising paragraph (h)(4) to read as follows: §60.17 Incorporations by reference . * * * * * (h) * * * (4) ANSI/ASME PTC 19.10

– 1981, Flue and Exhaust Gas Analyses [Part 10, Instruments and Apparatus], IBR approved for §60.63(i)(2) and (i)(4) of subpart F, Tables 1 and 3 of subpart EEEE, Tables 2 and 4 of subpart FFFF, Table 2 of subpart JJJJ, and §§60.4415(a)(2) and 60.4415(a)(3) of subpart KKKK of this part. * * * * * Subpart F-- [AMENDED] 3. The title of §60.62 is revised to read “Standards” instead of “Standards for particulate matter”. 4. Section 60.62 is amended by:89

a. Revising paragraph s (a)(1) and (a)(2) and adding paragraphs (a)(3) and (a)(4); b. Revising paragraph s (b)(1) and (b)(2); and

c. Adding paragraph (d) to read as follows: §60.62 Standards . (a) * * * (1) Contain particulate matter (PM) in excess of: (i) 0.15 kg per metric ton of feed (dry basis) to the kiln (0.30 lb per ton) if construction, reconstruction, or modification of the kiln commences after August 17, 1971 but on or before [INSERT DATE OF PUBLICATION IN FEDERAL REGISTE R]. (ii) 0.086 pound per ton of clinker if construction, reconstruction, or modification of the kiln commences after [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER]. (2 ) Exhibit greater than 20 percent opacity

. , except that this opacity limit does not apply to a kiln subject to the PM limit in paragraph (a)(1)(i) of this section that us es a bag leak detection system , ESP predictive model, or a PM continuous emission monitoring system. (3) Exceed 1.50 pounds of nitrogen oxide (NO X ) per ton of clinker on a 30
- day rolling average if construction, reconstruction, or modification of the kiln commences after [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER].90

(4) For sulfur dioxide (SO 2 ) emissions from a kiln for which construction, reconstruction, or modification commence s after [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER]: (i) Exceed 1.33 pounds per ton of clinker on a 30
- day rolling average; or (ii) The owner or operator must reduce SO 2 emissions exiting the kiln by 90 percent or greater. (b) * * * (1) Contain PM in excess of: (i) 0.050 kg per metric ton of feed (dry basis) to the kiln (0.10 lb per ton) if construction, reconstruction, or modification of the clinker cool er commence d after August 17, 1971 but on or before [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER]. (ii) 0.086 pound per ton of clinker if construction, reconstruction, or modification of the clinker cooler commences after [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER]. (2) Exhibit 10 percent opacity, or greater

. , .except that this opacity limit does not apply to a clinker cooler subject to the PM limit in paragraph (b)(1)(i) of this section that uses a ba g leak detection system , ESP predictive model or PM continuous emission monitoring system.91

* * * * * (d) If an affected facility subject to this subpart has a different emission limit or r equirement for the same pollutant under another regulation in t itle 40 of this chapter, the owner or operator of the affected facility must comply with the most stringent emission limit or requirement and is not subject to the less stringent requirement . 5. Section 60.63 is amended by: a. Revising paragraph (a); b. Revising paragraph (b); c. Revising the first sentence in paragraph (c) ; d. Adding paragraphs (f) through ( n ) to read as follows: §60.63 Monitoring of operations. (a) The owner or operator of any portland cement plant subject to the provis ions of this subpart shall record the daily clinker production rates and kiln feed rates. (b) The owner or operator of a kiln or clinker cooler must monitor PM emissions according to the applicable requirements in paragraph (b)(1) or (2) of this section. (1) For a kiln or clinker cooler that that was constructed, reconstructed, or modified after August 17, 197192

but on or before [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER], the owner or operator must: (i) Install, calibrate, maint ain, and operate in accordance with §60.13 a continuous opacity monitoring system (COMS) to measure the opacity of emissions discharged into the atmosphere from any kiln or clinker cooler except as provided in paragraph (c) of this section. Each owner or operator of an affected kiln or clinker cooler for which the performance test required under §60.8 has been completed on or prior to December 14, 1988, must install the COMS within 180 days after December 14, 1988. The COMS must be installed on each stack of any multiple stack control device for emissions from any kiln or clinker cooler. If there is a separate bypass stack installed, the owner or operator also must install, calibrate, maintain, and operate a COMS on each bypass stack in addition to the ma in control device stack; or (ii) Install, operate, and maintain a bag leak detection system on each fabric filter used to control PM emissions according to the procedures in paragraph (f) of this section; or (iii) Install, operate, and maintain an instrument for continuously monitoring and recording the concentration of PM emissions into the atmosphere according to the requirements in paragraph ( g ) of this section.93

(2) For a kiln or clinker cooler that is constructed, modified, or reconstructed or afte r [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER], the owner or operator must: (i) Install, operate, and maintain a bag leak detection system on each fabric filter used to control PM emissions according to the requirements in paragraph ( f) of this section ; and (ii) Monitor the performance of any electrostatic precipi tator (ESP) used to control PM emissions according to the requirements in paragraph (o) of this section; or (i i i) Install, operate, and maintain an instrument for continuous ly monitoring and recording the concentration of PM emissions into the atmosphere according to the requirements in paragraph (g) of this section. (c) Each owner or operator of a kiln or clinker cooler that was constructed, reconstructed, or modified on or before [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER], using a positive
-pressure fabric filter with multiple stacks, or a negative
-pressure fabric filter with multiple stacks, or an

e lectrostatic precipitator with multiple stacks may, instead of installing the COMS required by paragraph (b)(1)(i) of this section , monitor visible emissions at least once per day by using a certified visible emissions observer. * * *94

* * * * * (f ) The owner or operator must install, operate, and maintain the bag leak detection system according to paragraphs (f)(1) through (3) of this section. (1) Each bag leak detection system must meet the specifications and requirements in paragraphs (f)(1)(i ) through (viii) of this section. (i) The bag leak detection system must be certified by the manufacturer to be capable of detecting PM emissions at concentrations of 1 milligram per dry standard cubic meter (0.00044 grains per actual cubic foot) or less . (ii) The bag leak detection system sensor must provide output of relative PM loadings. The owner or operator shall continuously record the output from the bag leak detection system using electronic or other means (e.g., using a strip chart recorder or a data logger). (iii) The bag leak detection system must be equipped with an alarm system that will sound when the system detects an increase in relative particulate loading over the alarm set point established according to paragraph (f)(1)(iv) of this

se ction, and the alarm must be located such that it can be heard by the appropriate plant personnel.95

(iv) In the initial adjustment of the bag leak detection system, you must establish, at a minimum, the baseline output by adjusting the sensitivity (range) and the averaging period of the device, the alarm set points, and the alarm delay time. (v) Following initial adjustment, you shall not adjust the averaging period, alarm set point, or alarm delay time without approval from the Administrator or delegated authority except as provided in paragraph (f)(1)(vi) of this section. (vi) Once per quarter, you may adjust the sensitivity of the bag leak detection system to account for seasonal effects, including temperature and humidity, according to the procedures i dentified in the site
- specific monitoring plan required by paragraph (c)(2) of this section. (vii) You must install the bag leak detection sensor downstream of the fabric filter. (viii) Where multiple detectors are required, the system’s instrumentation and alarm may be shared among detectors. (2) You must develop and submit to the Administrator or delegated authority for approval a site
- specific monitoring plan for each bag leak detection system. You must operate and maintain the bag leak detection sys tem according to the site
specific monitoring plan at all times. Each monitoring plan96

must describe the items in paragraphs (f)(2)(i) through (vi) of this section. (i) Installation of the bag leak detection system; (ii) Initial and periodic adjustment o f the bag leak detection system, including how the alarm set
- point will be established; (iii) Operation of the bag leak detection system, including quality assurance procedures; (iv) How the bag leak detection system will be maintained, including a routi ne maintenance schedule and spare parts inventory list; (v) How the bag leak detection system output will be recorded and stored; and (vi) Corrective action procedures as specified in paragraph (f)(3) of this section. In approving the site
specific moni toring plan, the Administrator or delegated authority may allow owners and operators more than 3 hours to alleviate a specific condition that causes an alarm if the owner or operator identifies in the monitoring plan this specific condition as one that cou ld lead to an alarm, adequately explains why it is not feasible to alleviate this condition within 3 hours of the time the alarm occurs, and demonstrates97

that the requested time will ensure alleviation of this condition as expeditiously as practicable. (3) For each bag leak detection system, you must initiate procedures to determine the cause of every alarm within 1 hour of the alarm. Except as provided in paragraph (f)(2)(vi) of this section, you must alleviate the cause of the alarm within 3 hours of the alarm by taking whatever corrective action(s) are necessary. Corrective actions may include, but are not limited to the following: (i) Inspecting the fabric filter for air leaks, torn or broken bags or filter media, or any other condition that may

caus e an increase in PM emissions; (ii) Sealing off defective bags or filter media; (iii) Replacing defective bags or filter media or otherwise repairing the control device; (iv) Sealing off a defective fabric filter compartment; (v) Cleaning the bag leak detection system probe or otherwise repairing the bag leak detection system; or (vi) Shutting down the process producing the PM emissions. (g) The owner or operator of a kiln or clinker cooler using a PM continuous emission monitoring system ( CEMS ) to demonstrate compliance with the emission limit in §60.62(a) or98

(b) must install, certify, operate, and maintain the CEMS as specified in paragraphs (g)(1) through (3) of this section. (1) The owner or operator must conduct a performance evaluation of the PM CEMS according to the applicable requirements of §60.13, Performance Specification 11 of Appendix B of part 60, and Procedure 2 of Appendix F to part 60. (2) During each relative accuracy test run of the CEMS required by Performance Specification 11 of Appendix B to part 60, PM and oxygen (or carbon dioxide) data must be collected concurrently (or within a 30
- to 60
-minute period) during operation of the CEMS and when conducting performance tests using the following test methods: (i) For PM, Method 5 or 5B of Appendix A
- 5 to part 60 or Method 17 of Appendix A
- 6 to part 60. (ii) For oxygen (or carbon dioxide), Method 3, 3A, or 3B of Appendix A
- 2 to part 60, as applicable. (3) Procedure 2 of Appendix F to part 60 for quarterly accuracy determinations and da ily calibration drift tests. The owner or operator must perform Relative Response Audit’s annually and Response Correlation Audits every 3 years. (h) The owner or operator of a kiln constructed, modified or reconstructed on or after [INSERT DATE OF PUB LICATION IN FEDERAL REGISTER] must install, calibrate, maintain and operate99

a permanent weigh scale system, or use another method approved by the Administrator, to measure and record weight rates in tons -mass per hour of the amount of clinker produced. The system of measuring hourly clinker production must be maintained within ±5 percent accuracy. (i) Each owner or operator subject to the NO X emissions limit for a kiln in §60.62(a)(3) shall install, operate, calibrate, and maintain a n instrument for continuously monitoring and recording the concentration by volume of NO X emissions into the atmosphere. (j) Each owner or operator subject to the SO 2 emissions limit in §60.62(a)(4) for a kiln shall install, operate, calibrate, and mainta in an instrument for continuously monitoring and recording the concentration by volume of SO 2 emissions into the atmosphere. If complying with the alternative 90 percent SO 2 emissions reduction emission limit, you must also for continuously monitor and record the concentration by volume of SO 2 emissions at the wet scrubber inlet. (k) The owner or operator of each CEMS required under paragraphs (i) and (j) of this section, shall install, operate, and maintain each monitoring system according to Perf ormance100

Specification 2 (40 CFR part 60, appendix B) and the requirements in paragraphs (k)(1) through (5) of this section. (1) The span value of each NO X monitor shall be set at 125 percent of the maximum estimated hourly potential NO X emission

concen tration that translates to the applicable emission limit at full clinker production capacity. (2) The owner or operator shall conduct performance evaluations of each NO X monitor according to the requirements in §60.13(c) and Performance Specification 2 of Appendix B to part 60. The owner or operator shall use Methods 7, 7A, 7C, 7D, or 7E of appendix A
- 4 to part 60 for conducting the relative accuracy evaluations. The me thod ASME PTC 19.10
- 1981, “Flue and Exhaust Gas Analyses,” (incorporated by reference
- see §60.17) is an acceptable alternative to EPA Method 7 or 7C of Appendix A
- 4 to part 60. (3) The span value for the SO 2 monitor must be set at 125 percent of the maximum estimated hourly potential SO 2 emission concentration that translates to the applicable emission limit at full clinker production capacity. (4) The owner or operator must conduct performance evaluations of each SO 2 monitor according to the requirement s in §60.13(c) and Performance Specification 2 of Appendix B to part 60. The owner or operator shall use Methods 6, 6A, or 6C of1 01

Appendix A
- 4 to part 60 for conducting the relative accuracy evaluations. The method ASME PTC 19.10
- 1981, “Flue and Exhaust Gas Analyses,” (incorporated by reference
- see §60.17) is an acceptable alternative to EPA Method 6 or 6A of Appendix A
- 4 to part 60. (5) The owner or operator must comply with the quality assurance requirements in Procedure 1 of Appendix F to part 60 for each monitor, including quarterly accuracy determinations for monitors, and daily calibration drift tests. (l) The owner or operator of each CEMS required under paragraphs (i) and (j) of this section must operate the monitoring system and record data duri ng all periods of operation of the affected facility including periods of startup, shutdown, malfunction, except for continuous monitoring system breakdowns, repairs, calibration checks, and zero and span adjustments. (1) The owner or operator must obtain emission data for at least 18 hours in at least 22 out of 30 successive kiln operating days. For each valid hour, the owner or operator also must obtain valid exhaust flow rate da ta, as specified in paragraph (l)(6) of this section. (2) The owner or operator must meet the requirements of §60.13(h) when determining the 1
- hour averages of emissions data102

needed to meet the minimum data requirements specified in paragraph (l)(1) of this section. (m) Each owner or operator of a kiln subject to the NO X emissions limit in §60.62(a)(3) or the SO 2 emissions limit in §60.62(a)(4)(i) or (ii) must install, operate, calibrate, and maintain an instrument for continuously measuring and recording the exhaust flow rate to the atmosphere according to the requirement s in paragraphs (m)(1) through (9) of this section. (1) The owner or operator must install each sensor of the flow rate monitoring system in a location that provides representative measurement of the exhaust gas flow rate at the sampling location of the NOX and SO 2 CEMS, taking into account the manufacturer’s recommendations. (2) The flow rate monitoring system must be designed to measure the exhaust flow rate over a range that extends from a value of at least 20 percent less than the lowest expected exhaust flow rate to a value of at least 20 percent greater than the highest expected exhaust flow rate. (3) The flow rate monitoring system must have a minimum accuracy of 5 percent of the flow rate or greater. (4) The flow rate monitoring system must be equipped with a data acquisition and recording system that is capable of103

recording values over the entire range specified in paragraph (l)(2) of this section. (5) The signal conditioner, wiring, power supply, and data acquisition and recording system for th e flow rate monitoring system must be compatible with the output signal of the flow rate sensors used in the monitoring system. (6) The flow rate monitoring system must be designed to complete a minimum of one cycle of operation for each successive 15
-minute period. To have a valid hour of data, the flow rate monitoring system must measure and record at least three of four equally
- spaced data values (or at least 75 percent of the total number of values) for each hour (not including startup, shutdown, malfunction, or out
- of
- control periods). (7) The owner or operator must perform an initial calibration of the flow rate monitoring system according to manufacturer’s recommendations (8) The owner or operator must check the accuracy of the monitoring system a t least once per year according to manufacturer's recommendations. (9) The owner or operator must operate the flow rate monitoring system and record data during all periods of operation of the affected facility including periods of startup,104

shutdown, malfunction, except for monitoring system breakdowns, repairs, and calibration checks. ( n ) You must monitor the performance of any ESP specified i n paragraph (b) (2) (ii) of this section in accordance with the

r equirements in paragraph (o)(1) through (5) of this section. ( 1 ) You must calibrate the ESP predictive model with each PM control device used to comply with the applicable PM emissions limit in §6 0.62 ( a)(ii) or (b)(ii) operating under normal conditions. In cases when a wet scrubber is used in

combination with an ESP to comply with the PM emissions limit, the daily average liquid
- to - gas flow rate for the wet scrubber must be maintained at 90 percent of average ratio measured during all test run intervals for the performance test conducted according to paragraph (o)(1) of this section. ( 2 ) You must develop a site
- specific monitoring plan that includes a description of the ESP predictive model used, the model input parameters, and the procedures and criteria for establishing monitoring parameter base line levels indicative of compliance with the PM emissions limit. You must submit the site
- specific monitoring plan for approval by the permitting authority. For reference purposes in preparing the monitoring plan, see the OAQPS “Compliance Assurance Mon itoring (CAM) Protocol for an Electrostatic Precipitator (ESP) Controlling105

Particulate Matter (PM) Emissions from a Coal
- Fired Boiler.” This document is available from the U.S. Environmental Protection Agency (U.S. EPA); Office of Air Quality Planning and Standards; Sector Policies and Programs Division; Measurement Policy Group (D243

– 02), Research Triangle Park, NC 27711. This document is also available on the Technology Transfer Network (TTN) under Emission Measurement Center Continuous Emission Monitor ing. ( 3 ) You must run the ESP predictive model using the applicable input data each boiler operating day and evaluate the model output for the preceding boiler operating day excluding periods of affected source startup, shutdown, or malfunction. If the values for one or more of the model parameters exceed the applicable baseline levels determined according to your approved site
- specific monitoring plan, you must initiate investigation of the relevant equipment and control systems within 24 hours of the fi rst discovery of a model parameter deviation and, take the appropriate corrective action as soon as practicable to adjust control settings or repair equipment to return the model output to within the applicable baseline levels. ( 4 ) You must record the ESP predictive model inputs and outputs and any corrective actions taken. The record of corrective action taken must include the date and time during106

which the model output values exceeded the applicable baseline levels, and the date, time, and description o f the corrective action. ( 5 ) If after 7 consecutive days a model parameter continues to exceed the applicable baseline level, then you must conduct a new PM performance test according to paragraph (o)(1) of this section. This new performance test must be conducted within 60 days of the date that the model parameter was first determined to exceed its baseline level unless a wavier is granted by the permitting authority. 6. Section 60.64 is amended by: a. Revising paragraph (b) introductory text and paragraph (b)(1); and b. Adding paragraphs (b)(5) , b(6), and (c) to read as follows: §60.64 Test methods and procedures. * * * * * (b) The owner or operator must determine compliance with the PM standard in §60.62(a)(1) as follows: (1) The emission rate (E) of PM must be computed for each run using the Equation 1 of this section:



# K) )/(P Q (c E sd s 

#  (Eq. 1)107

Where: E = emission rate of particulate matter, kg/ metric ton (lb/ton) of kiln feed; Cs = concentra tion of particulate matter, g/ dscm (gr/dscf); Qsd = volumetric flow rate of effluent gas, dscm/hr ( dscf/hr); P = total kiln feed (dry basis) rate, metric ton/ hr (ton/hr). For kilns constructed, modified or reconstructed on or after [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER], p = total kiln clinker production rate; and K = conversion factor, 1000 g/kg (7000 gr/lb). * * * * * (5) The owner or operator of a kiln (including any associated alkali bypass and clinker cooler) that is constructed, modified or reconstructed on or after [INSERT DATE OF PUBLICATION IN FEDERAL REGISTER], must conduct a performance test every 5 years following the initial performance test. Kilns (including any associated alkali bypass and clinker cooler) constructed, reconstructed, or modified after August 17, 1971 but on or before [INSERT DATE OF PUBLICATION IN FEDE RAL REGISTER] must conduct a performance test every 5 years. (6) Any sources other than kilns (including associated alkali bypass and cooler) subject to the 10 percent opacity limit must foll ow the appropriate monitoring procedures in §63.1350 of part 63. ( c ) The owner or operator must calculate and record the 30
- day rolling emission rate of NO X and SO 2 as the total of all hourly emissions data for a cement kiln in the preceding 30108

days, divided by the total tons of clinker produced in that kiln during the same 30
- day period using Equation 2 of this section:



# K) )/(P Q (c E sd s 

#  (Eq. 2)
Where: E = emission rate of NOX or SO 2 , kg/metric ton (lb/ton) of clinker production; Cs = concentration of NOX or SO 2 , g/dscm (gr/dscf); Qsd = volumetric flow rate of effluent gas, dscm/hr (dscf/hr); P = total kiln clinker production rate, metric ton/hr (ton/h r).; and K = conversion factor, 1000 g/kg (7000 gr/lb). 7. Section 60.66 is revised to read as follows: §60.66 Delegation of authority . (a) This subpart can be implemented and enforced by the U.S. EPA or a delegated authority such as a State, local, or tribal agency. You should contact your U.S. EPA Regional Office to find out if this subpart is delegated to a State, local, or tribal age ncy within your State. (b) In delegating implementation and enforcement authority to a State, local, or tribal agency, the approval authorities contained paragraphs (b)(1) through (4) of this section are retained by the Administrator of the U.S EPA and ar e not transferred to the State, local, or tribal agency. (1) Approval of an alternative non
- opacity emission standard.109

(2) Approval of a major change to test methods under §60.8(b). A “major change to test method” is defined in 40 CFR 63.90. (3) Approval of a major change to monitoring under §60.13(i). A “major change to monitoring” is defined in 40 CFR 63.90. (4) Approval of a major change to recordkeeping/reporting under §60.7(b) through (f). A “major change to recordkeeping/reporting” is defined i n 40 CFR 63.90. PART 63— [AMENDED] 8. The authority citation for part 63 continues to read as follows: Authority: 42 U.S.C. 7401, et seq . Subpart LLL

— [Amended] 9. Section 63.1356 is amended to read as follows: §63.1356 Sources with multiple Emission Limits in Title 40 of this Chapter If an affected facility subject to this subpart has a different emission limit or requirement for the same pollutant under another regulation in title 40 of this chapter, the owner or operator of the affected facility must comply with the most stringent emission limit or requirement and is exempt from the less stringent requirement .110