[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 after [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 PROPOSED RULE IN THE FEDERAL 

REGISTER]. Under the Paperwork Reduction Act, comments on the 

information collection provisions must be received by the Office 
2

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. EPAHQ-OAR-2007-0877, 1200 Pennsylvania Ave., NW, 

Washington, DC 20460. Please include a total of two 

copies. In addition, please mail a copy of your 

comments on the information collection provisions to 

the Office of Information and Regulatory Affairs, 

Office of Management and Budget (OMB), Attn: Desk 

Officer for EPA, 725 17th St., NW, Washington, DC 

20503.

• Hand Delivery: In person or by courier, deliver 

comments to: EPA Docket Center (6102T), Standards of 

Performance (NSPS) for Portland Cement Plants Docket, 

Docket ID No. EPA-HQ-OAR-2007-0877, EPA West, Room 

3334, 1301 Constitution Avenue, NW, Washington, DC 
3

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. EPAHQ-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 the comment includes 

information claimed to be Confidential Business Information 

(CBI) or other information whose disclosure is restricted by 

statute. Do not submit information that you consider to be CBI 

or otherwise protected through www.regulations.gov or e-mail. 

The www.regulations.gov website is an “anonymous access” system, 

which means EPA will not know your identity or contact 

information unless you provide it in the body of your comment. 

If you send an e-mail comment directly to EPA without going 

through www.regulations.gov, your e-mail address will be 

automatically captured and included as part of the comment that 

is placed in the public docket and made available on the 

Internet. If you submit an electronic comment, EPA recommends 

that you include your name and other contact information in the 

body of your comment and with any disk or CD-ROM you submit. If 

EPA cannot read your comment due to technical difficulties and 
4

cannot contact you for clarification, EPA may not be able to 

consider your comment. Electronic files should avoid the use of 

special characters, any form of encryption, and be free of any 

defects or viruses.

Docket: All documents in the docket are listed in the 

www.regulations.gov index. Although listed in the index, some 

information is not publicly available, e.g., CBI or other 

information whose disclosure is restricted by statute. Certain 

other material, such as copyrighted material, will be publicly 

available only in hard copy. Publicly available docket 

materials are available either electronically in 

www.regulations.gov or in hard copy at the EPA Docket Center, 

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, telephone 
5

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 Cement 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 Act
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E. Executive Order 13132: Federalism

F. Executive Order 13175: Consultation and Coordination with 

Indian Tribal Governments

G. Executive Order 13045: Protection of Children from

Environmental Health Risks and Safety Risks

H. Executive Order 13211: Actions Concerning Regulations That 

Significantly Affect Energy Supply, Distribution, or Use

I. National Technology Transfer Advancement Act

J. Executive Order 12898: Federal Actions to Address

Environmental Justice in Minority Populations and LowIncome Populations

I. General Information

A. Does this action apply to me?

Categories and entities potentially regulated by this 

proposed rule include: 

Category NAICS 

code1

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 criteria 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 prepare my comments to EPA?

Do not submit information containing CBI to EPA through 

www.regulations.gov or e-mail. Send or deliver information 

identified as CBI only to the following address: Roberto 

Morales, OAQPS Document Control Officer (C404-02), Office of Air 

Quality Planning and Standards, Environmental Protection Agency, 

Research Triangle Park, NC 27711, Attention Docket ID No. EPAHQ-OAR-2007-0877. Clearly mark the part or all of the 

information that you claim to be CBI. For CBI information in a 

disk or CD-ROM that you mail to EPA, mark the outside of the 

disk or CD-ROM as CBI and then identify electronically within 

the disk or CD-ROM the specific information that is claimed as 

CBI. In addition to one complete version of the comment that 

includes information claimed as CBI, a copy of the comment that 

does not contain the information claimed as CBI must be 

submitted for inclusion in the public docket. Information so 

marked will not be disclosed except in accordance with 

procedures set forth in 40 CFR part 2.

C. Where can I get a copy of this document?

In addition to being available in the docket, an electronic 

copy of this proposed action is available on the Worldwide Web 

(WWW) through the Technology Transfer Network (TTN). Following 

signature, a copy of this proposed action will be posted on the 

TTN’s policy and guidance page for newly proposed or promulgated 
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rules at http://www.epa.gov/ttn/oarpg. The TTN provides 

information and technology exchange in various areas of air 

pollution control.

D. When would a public hearing occur?

If anyone contacts EPA requesting to speak at a public 

hearing by [INSERT DATE 10 DAYS AFTER DATE OF PUBLICATION IN THE 

FEDERAL REGISTER], a public hearing will be held on [INSERT DATE 

15 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. 

Persons interested in presenting oral testimony or inquiring as 

to whether a public hearing is to be held should contact Mr. 

Keith Barnett, listed in the FOR FURTHER INFORMATION CONTACT

section, at least 2 days in advance of the hearing.

II. Background Information 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 which 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 in 
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achieving long-term emissions reductions in numerous industries 

by assuring cost-effective controls are installed on new, 

reconstructed, or modified sources.

Section 111 of the CAA requires that NSPS reflect the 

application of the best system of emission reductions 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 must 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). Today’s proposal 

considers all of these factors, including both short- and longterm 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 for 
10

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 test data to insure that control devices 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 of Performance For Portland 

Cement Plants (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 (PCP) 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 (NOx) emission limit of 1.50 lb/ton of 

clinker on a 30-day, 24-hour rolling average basis. 

Add paragraph (a)(4) which requires kilns constructed, 

reconstructed, or modified after [INSERT DATE OF 

PUBLICATION IN THE FEDERAL REGISTER] to meet either a 

sulfur dioxide (SO2) emission limit of 1.33 lb/ton of 
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clinker on a 30-day, 24-hour rolling average basis or 

demonstrate a 90-percent reduction in SO2 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 PUBLICATION IN THE FEDERAL REGISTER]. 

Add a paragraph (b)(1)(ii) which limits PM emissions 

from clinker coolers constructed, reconstructed, or 

modified 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 requirements 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 NOx continuous emission 

monitoring system for each kiln subject to the NOx

emission limit.

Add paragraph (j) to require a SO2 continuous emission 

monitoring system for each kiln subject to the SO2

emission limit.

Add paragraph (k) to require that NOX and SO2

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 paragraph (l) to require that NOX and SO2 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 

NOx or SO2 emissions limit.

Add paragraph (n) to require 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 NOx and SO2 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 F 
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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 from lb/ton 

of dry feed to lb/ton of clinker product;

 To reduce the PM emission limit for kilns from 0.3 lb/ton 

of dry feed to 0.086 lb/ton of clinker;

 To set a limit on NOX emissions from kilns of 1.50 lb/ton of 

clinker; and

 To set a limit on SO2 emissions from kilns of 1.33 lb/ton of 

clinker, or, in the alternative, demonstrate a reduction in 

SO2 emissions from the kiln of at least 90 percent;

 To reduce the PM emissions limit for clinker coolers from 

0.1 lb/ton dry feed to 0.086 lb/ton of clinker; and

 To 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 States 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 nonair environmental impacts. The main difference between those 

determinations and a BDT determination for purposes of a new 

source performance standard is that a BACT determination is made 

on a site-specific basis. Therefore, in evaluating BACT 

determinations, we have to account for any site-specific factors 

that may not be applicable to the source category as a whole. 

We have also reviewed data gathered in support of related rules 

involving the portland cement industry, notably the National 

Emission Standards for Hazardous Air Pollutants (NESHAP) for 

portland cement kilns issued pursuant to section 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 discussions 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 capacity.

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/precalciner 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 State permitting processes than those 

currently in the PCP NSPS. In addition, many State permits 

contain emission limits for NOX and SO2, 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 NOX emissions are increasingly being 

used to meet State permit limits. Our review of permits, BACT 

determinations, and emissions test data show that SO2 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 SO2 emissions in order to meet State SO2

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 route 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 the 
18

clinker cooler gas flow exhausts directly to atmosphere 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 preheater/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, in one such case a wet kiln was 

converted to a semi-dry process that included a 

preheater/precalciner. Performance data from this kiln indicate 

that the emissions of SO2 and NOx 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 believes 

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 ability 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 production processes. As an example, assume 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 inputbased 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 input is now 2.04 

million tons), this kiln would be allowed to emit 927 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 NOX under the 1.5 lb/ton of clinker 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 NOX and SO2 emission limits 

on a 30 day rolling average. We believe this will alleviate the 
21

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-specific 

configurations and operational limitations.3

In the following discussions, emissions were typically 

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 an 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 on 

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 Technical 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 separate exhaust stack that had become subject to the 

NSPS, 17 were controlled by fabric filters, and four were 

controlled by gravel bed filters. (Gravel bed filters perform 

similarly to fabric filters except they use a moving bed of 

gravel to capture the particulate 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 filters 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 the 
23

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 from fabric filters does occur due to seepage 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 this industry 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

measured by EPA Reference Method 5 (40 CFR part 60, Appendix A3). The first set was comprised of 21 emission tests of 

portland cement kilns equipped with fabric filters at various 

domestic locations which fabric filters were (reportedly)

equipped with membrane bags. These PM emissions 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 representative of 

the most current designs. We also reviewed 37 emissions tests 

for PM from Florida kilns equipped 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. Although 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 

equipped 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 principle 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 portland 

cement kilns 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 basis 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 95th or 99th percentile, and adding this value to the 

average of all the tests. The result was we determined that a 

level of 0.0830 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 different 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 fabric 
27

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 compliance test and variability 

associated with the performance of the control equipment over 

time. See generally 72 FR 54878-79, September 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 shortterm variability alone, see 72 FR 54878). The standard under 

this analysis is 0.0069 gr/dscf corrected to 7 percent 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 clinker.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 accounts for all of the potential 
28

operating variability associated with operation of a membranebag fabric filter. 

We evaluated the costs of the different control levels 

discussed above. This evaluation, and all subsequent cost, 

environment, and energy impacts 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 tpy. 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, temperatures, etc.) may be 

found in the Technical Support Document (See Footnote 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 

not 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 million tpy of clinker production 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 

total PM control accepted as reasonable for other stationary 

sources. See, e.g. 70 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 9876, 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 PM 
30

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 Compilation of Emission Factors (AP-42), 45 

percent of the PM from a cement kiln fabric filter is fine PM. 

Therefore, the 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 alkali 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 fabric 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 any 
31

adverse energy impacts because membrane 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 Method 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 

condensable 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 were 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 preheater/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 which 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 variability. 

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 NOX. 

Concurrent with this 8-year review we are proposing an NSPS for 

NOX that would 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 NOX

formation. In cement kilns, NOX emissions are formed during fuel 

combustion primarily by the oxidation of molecular nitrogen 

 

7 Information on NOX emissions from preheater/precalciner kilns, 

factors affecting NOx emissions, process controls that reduce NOX

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 NOX) and the 

oxidation of nitrogen compounds in fuel (referred to as fuel 

NOX). Many States issuing construction and operating permits for 

new kilns have specified emission limits for NOX. EPA’s 

BACT/RACT/LAER Clearinghouse database shows that for the period 

2001 through 2007, 30 determinations for new, modified or 

reconstructed kilns included NOX limits. Emissions 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 NOX

burners and SCC emit on average about 2.5 lb/ton of clinker. 

The exclusive add-on control used to reduce NOX emissions from 

kilns operating in the U.S. is selective noncatalytic reduction 

(SNCR). In Europe, selective catalytic reduction (SCR) has been 

used to reduce NOX emissions from a few cement kilns. In recent 

Prevention of Significant Deterioration permits for portland 

cement kilns, States have determined BACT emission limits for NOX

based on the use of SNCR in combination with well-designed SCC 

and other process designs such as low NOX 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 to 
35

the given gas stream. On average, SNCR achieves approximately a 

35 percent reduction in NOX 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 NOX 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 cement 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 NOX reduction achievable by an SNCR system. 

Another NOX control technology, SCR, is used in the electric 

utility industry to reduce NOX emissions from boilers and has 

been used worldwide on three cement kilns in Europe. SCR is 

capable of reducing NOX emissions by about 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 NOX 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 NOX

emissions considering costs and other impacts.

In proposing a NOX emission limit, we reviewed recently 

issued permits, recent BACT determinations and recent emissions 

data for preheater/precalciner kilns to establish potential NOX

control levels for evaluation. Most of the emission limits and 

test data are 30 day averages 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. NOX

emissions from three recently permitted preheater/precalciner 

kilns utilizing well-designed and operated process designs 

including SCC, averaged NOX 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 NOX emissions. Changes in the kiln 
37

feed rate, chemical composition, or moisture content of raw 

materials can cause kiln temperatures to vary with significant 

variation in NOX emissions. Even raw materials from the same 

quarry can vary in chemical 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 be heated longer and at higher temperatures 

to volatilize and remove the alkali compounds. With higher 

temperatures and longer residence times, NOX 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 control. 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 as baseline of a new 

preheater/precalciner kiln designed without SCC or low NOx 
38

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 NOx combustion 

technologies. Therefore we have no data to determine the 

appropriate NOx emission level for a new preheater/precalciner 

kiln that does not incorporate low-NOx 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 NOX 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 uncontrolled 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 NOX emissions. Data on SNCR show a performance that 

ranges from approximately 20 to 80 percent NOX 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 NOX 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 NOX removal efficiency was obtained at a 

70 ppm; at 200 ppm the NOX removal efficiency increased to 54 

percent. We estimate that for an SNCR with optimal injection 

configuration and reagent injection rate, a 50 percent NOX

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 NOX 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 NOX emission levels 
40

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 analysis 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 costs

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 cost effectiveness at the 1.95 lb/ton of 

clinker level was approximately $2,000 per ton of NOX reduction 

and at the 1.5 lb/ton of clinker level was approximately $2,100 

per ton of NOX reduction. This level of cost effectiveness for 

both options compares favorably with the reference range of NOX

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 the 
41

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 clinker 

based on the performance of SCR. SCR is the process of adding 

ammonia or urea in the presence of a catalyst to selectively 

reduce NOX 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 NOX 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 kilns, 

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 cement 
42

plants 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 economical. 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 pressurized 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 technology’s use). To move exhaust gases 

past or through the catalyst, there will be an additional 

pressure drop that may require that existing air-handling 
43

equipment, such as fans and blowers, be scaled up. Other 

concerns include the oxidation of SO2 to SO3 by the SCR catalyst, 

catalyst masking by CaSO4 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. 

To 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 lowdust system 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 NOX in the gas stream. Reheating is typically 

accomplished using 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 500 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 SO2 may increase.

EPA estimates the costs of installing an SCR system to be 

$5.7 million in capital cost and $3.1 million annualized cost. 
44

The resulting average NOX emissions reduction would be 1,200 tpy 

over baseline, and the incremental NOX 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 NOX 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 factors

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, and 
45

adverse non-air and energy implications, EPA is not proposing 

SCR as BDT for portland cement 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 have in the generation of condensable PM 

emissions, and what actions, if any, are available to mitigate 

those impacts.

4. SO2

In the previous NSPS review, we declined to set SO2

standards because there were no demonstrated add-on SO2 control 

technologies applied to cement kilns (53 FR 50354, December 14, 

1988). Since that time at least two SO2 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 determinations 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, SO2 comes from two sources. The first is 

sulfur in the coal fuel (fuel SO2). Most fuel SO2 mixes with 

lime in the kiln and preheater and is not emitted into the 

atmosphere. The other and potentially more important source of 

SO2 is the raw materials (raw materials SO2). Sulfides or 

elemental sulfur in the raw materials may be oxidized to SO2 in 

the kiln system where sufficient oxygen is present. Through the 

inherent scrubbing ability of the alkaline raw materials, this 

SO2 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 SO2 generated is 

removed by the natural 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 SO2 emissions can be significant. Add-on controls 

may be necessary in those situations.

Cement kilns faced with high SO2 emissions due to high 

sulfur levels in raw materials have used either wet scrubbers or 

lime injection for SO2 emission control. Wet scrubbers applied 

to cement kilns typically achieve at least a 90 percent or more 
47

reduction in SO2 emissions.9 A recently installed scrubber on a 

cement plant with high uncontrolled SO2 emissions due to highsulfur raw materials was designed to achieve a 95 reduction in 

SO2 emissions.10 A 95 percent SO2 reduction is consistent with 

other information on the performance of scrubbers for SO2

removal.11 Assuming the wet scrubber is correctly sized 

(typically a liquid-to-gas ratio of 30 gallons per 1,000 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 SO2. At some 

facilities lime injection is only used when increases on SO2

emission above a specified level are detected, such as when the 

raw mill is down. The percent reduction in SO2 emissions is a 

function of the inlet SO2 concentrations and lime injection 

rates. Increasing either increases the percent reduction in SO2 

emissions. Dry lime systems can reportedly achieve a SO2 

emissions reduction of up to approximately 70 to 75 percent,

though one vendor claims potential reductions 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

percent.12 We evaluated three control options using three levels 

of uncontrolled SO2 emissions: low, moderate and high 

uncontrolled SO2 emissions. For examples of kilns with low 

uncontrolled sulfur emissions, we considered kilns operating in 

the State 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 SO2 emissions of 

0.20 lb/ton of clinker is BACT, Florida State 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 SO2 by finely divided lime in the kiln and 

calciner.14 

As noted above, high uncontrolled SO2 emissions can occur 

when pyritic sulfur is present in the raw materials and SO2

emissions are left uncontrolled. Where such cases have 

occurred, add-on controls have been used to reduce SO2 emissions. 

Uncontrolled SO2 emissions of about 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, December 21, 2005.
49

being added.15 At a reported production capacity of 800,000 

tpy16, uncontrolled SO2 emissions would be about 13 lb/ton of 

clinker. This is considered representative of a high 

uncontrolled SO2 emission level. A moderate uncontrolled SO2

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 SO2 emission levels discussed above are based on 

long term average performance, typically 30 days. New cement 

kilns with SO2 emission limits typically have continuous SO2

monitors. In reviewing CEM data we noted that the averaging 

period affects the achievable SO2 emission level. Longer 

averaging periods result in lower average SO2 levels (since 

variability tends to be averaged out with multiple measurements 

over time). 

The first control option we considered was no additional 

control of SO2 other than the inherent control achieved by the 

kiln and the raw mill. State BACT determinations usually 

identify inherent SO2 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 of 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 

deficiency of this option is that some kilns would have moderate 

or high uncontrolled emissions of SO2, due to the presence of 

pyritic sulfur in their raw materials, which emissions would be 

readily controllable with air pollution control equipment which 

in fact 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 SO2 emission levels were sufficiently high that an 

alkaline wet scrubber was installed to reduce SO2 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 SO2 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 SO2

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 SO2 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 SO2 emissions reduction 
51

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 content of the raw materials is so 

high that, even with the most efficient SO2 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 achievable for a well designed and operated wet 

scrubber.19 Compliance with the 90 percent reduction would be 

determined by continuously monitoring SO2 at the control device 

inlet and outlet. Continuous monitoring of SO2 at the inlet and 

outlet is a positive demonstration that the standard is being 

continuously met. 

We estimate that reducing high uncontrolled SO2 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 SO2 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 SO2 emission controls considered to be “highly 

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 SO2 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 SO2 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 SO2 emission levels sufficient to warrant the use of 

a scrubber to reduce SO2 emissions to the level of 1.33 lb/ton of 

clinker or, alternatively, demonstrate a 90 percent reduction in 

SO2 emissions.

We rejected Options 3 and 4 because they would have 

resulted in cement kilns with moderate uncontrolled SO2 emission 

levels having to apply add-on controls, either dry lime sprayers 

at a cost of approximately $6,300 per ton of SO2 reduction under 

Option 3 or a wet scrubber at a cost of approximately $6,700 per 

ton of SO2 reduction under Option 4.21 Not only do these options 

result in a higher cost per ton of SO2 reduction than Option 2, 

but Options 3 and 4 would not be likely to achieve any 

significant additional SO2 emission reductions over Option 2 for 

kilns emitting high uncontrolled levels of SO2 because Option 2 

already represents a 90 percent emission reduction control for 

high sulfur raw materials.
53

The proposed SO2 emissions limit of 1.33 lb/ton of clinker

should not result in any non-air environmental impacts. Liquid 

waste from 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 devices and, in the case of a wet scrubber, increased 

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, are using wet scrubbers to control SO2 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 SO2

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 SO2 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 today 
54

is achieved for future affected kilns in those situations where 

the presence of pyritic sulfur raw materials would otherwise 

result in high uncontrolled SO2 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 result 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 new 

cement kilns are currently subject to a continuous 20 parts 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 determined 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 information 
55

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, 

regardless 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 oxidizer 

add-on control, which is also the most effective CO emission 

control available for this source category. Therefore we 
56

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 to 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 

because the majority of kilns already have a similar testing 

requirement under the Portland Cement NESHAP, 40 CFR 63, subpart 

LLL.

There are no NOX or SO2 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 detection systems must be 

installed and operated according to the proposed §60.63(f) 

requirements. If a new facility installs an ESP we are 

proposing to require 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 currently subject to the 

NSPS, we are also providing an option to install a BLD to 

monitor compliance 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 source 
58

that installs a BLD or PM CEMS, the opacity standard would no 

longer apply.21

For all 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 contained in the Portland Cement NESHAP, 40 CFR 

part 63, subpart LLL. 

Under the proposed amendments, compliance with the emission 

limits for NOX and SO2 would be determined using continuous 

emissions monitoring systems (CEMS). This requirement is 

consistent with recent State permit requirements that require 

continuous monitoring for NOX and SO2. 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 SO2 emission limit of 90 

percent reduction would also be required to continuously monitor

SO2 emissions at the scrubber inlet. The cost impacts shown in 

the preamble include all monitoring costs.21

D. Why are we not proposing to revise the other 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 percent. 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 from applicable standards under the NSPS 

and the Metallic Minerals Processing NSPS (subpart OOO). That 
60

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 result, 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 stringent limit, and is 

not subject to the less stringent limit.

F. What is EPA’s sector-based approach and how is it relevant to 

this rulemaking?

In the National Academy of Science’s 2004 report, “Air 

Quality Management in the United States,” the National 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 

coordinated manner. With these recommendations, EPA began to 

move towards establishing multi-pollutant and sector-based 

approaches to managing emissions and air quality. These sectorbased approaches essentially expand technical analyses on costs 

and benefits of 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, considering 
61

feasibility, costs, and benefits 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 other 

regulatory requirements for portland cement facilities currently 

under review and/or reconsideration. The requirements analyzed 

would affect HAP and/or criteria pollutant emissions from cement 

kilns 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-CO standard and the NESHAP THC standard discussed above. As 
62

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 emissions 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 standard 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 pollutant, 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 extend 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 Toxics 
63

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 proposed SO2 standard under the NSPS. As 

described above, the proposed standard for SO2 control is 1.33 

lb/ton of clinker, or in the alternative, demonstration of a 90 

percent SO2 emissions reduction measured across the control 

device, such as an alkaline scrubber. Under the NESHAP 

reconsideration, EPA may amend the MACT standard for Hg for new 

and existing sources. A facility that is considering adding a 

new source that may be subject to SO2 add-on control requirements 

will have to consider the interaction of their choice of SO2 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 SO2 reduction would meet the SO2 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 control of both 

SO2 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 technical 
65

factors such as the type of kiln, associated capacity, 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 greenhouse gas emissions from the 

portland cement industry? 

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 petroleum refineries, we believe that 

it is appropriate in the first instance to consider issues 

related to the regulation of GHGs under the CAA through the 
66

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 Amendments 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 identified 

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 final 

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 

differences 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 promulgation 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 operation 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 than 

0.5 lb/ton of clinker, the current NSPS limit. We estimate that 

the PM reduction per kiln 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 NOX, 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 

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

Under the proposed limit for SO2, 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 SO2 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 SO2 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 SO2 as a result of this proposed rule are required to 

apply wet scrubbers as a result of the current mercury emission 

requirements in the Portland 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 with the new NOX and SO2 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 for 
69

NOX, and 9.36 tpy for SO2. 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 SO2 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 slurry 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 required on all kilns. Where 

one is present, the amount of solid waste generated from the 

alkali bypass is minimal, usually about 1 percent of total 
70

cement kiln dust captured in control devices, because the bypass 

gas stream is a small percentage of total kiln exhaust gas flow 

and the bypass gas stream does not contact the feed stream in 

the raw mill.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 these proposed revisions (which are 

minimal, as just discussed). We estimate that these 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 control SO2 emissions. These 

increases are estimated to be 15 tpy of NOX, 8 tpy of CO, 26 tpy 

of SO2 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 deliver 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 be 
71

utilized to comply with the proposed standards. This proposal 

will likely result in the addition of alkaline scrubbers to 

certain kilns to reduce SO2 emissions. We estimate the 

additional national electrical demand to be 6.9 million kWhr per 

year by the end of the 5th year.

F. What are the cost impacts?

Under the proposed amendments, the cost for new kilns are 

based on the use of NOX and SO2 continuous emissions monitors, 

bag leak detectors, SNCR for NOX 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 SO2

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 

$3,900,000 kilns 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 $190,000,000. The estimated total annualized 

cost per new kiln will be $1,500,000 for kilns that do not 

install wet scrubbers and $6,400,000 for those that do install 

wet scrubbers. National annualized costs will be $50,000,000.

The national costs shown above are considered to be a 

conservative estimate because they do not include the potential 

impact of requirements for new sources in the Portland Cement 
72

NESHAP, which limits mercury emission form new kilns to 41 

micrograms per dry standard cubic meter (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 SO2 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 SO2 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 in 
73

this preamble. We performed an economic impact analysis that 

estimates changes in prices and output for portland cement 

manufacturing nationally using the annual compliance costs 

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 the 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 could potentially spend up to $6.4 million 

dollars per year to meet the selected control options for NOX, 

SO2, and PM (see Table 2 of this preamble). The average cost 

per ton of capacity is approximately $5. In contrast, new kilns 

using moderate or low sulfur 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 type

Number 

of kilns 

(5-year 

period)

Total 

annualized 

costs 

($million)

New source 

unit cost 

($/metric 

ton of 

capacity)
74

High sulfur raw materials 4 $6.4 $5

Moderate or low sulfur raw 

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 material 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 of operating profit rates for new kilns, new 

kilns using high sulfur content raw materials could potentially 

have significantly reduced operating profits. 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 

opportunities 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, depending 
75

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 submitted 

this action to OMB for review under Executive Order 12866, and 

any changes made in response to OMB recommendations have been 

documented in the docket for this action.

B. Paperwork Reduction Act

The information 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 be 
76

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 

NOx and SO2 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 requirements are specifically 

authorized by section 114 of the CAA (42 U.S.C. 7414). All 

information submitted to EPA pursuant to the recordkeeping and 

reporting requirements for which a claim of confidentiality is 

made is safeguarded according to EPA policies set forth in 40 

CFR part 2, subpart B.

The annual burden for this information collection averaged 

over the first 3 years of this ICR is estimated to total 4,428

labor-hours per year at a cost of $416,179 per year. The 

annualized capital costs are estimated at $59,035 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 17th Street, NW, Washington, DC 20503, Attention: 

Desk Office for EPA. Since OMB is required to make a decision 

concerning the ICR between 30 and 60 days after [INSERT DATE OF 

PUBLICATION IN THE FEDERAL REGISTER], a comment to OMB is best 

assured of having its full effect if OMB receives it by [INSERT 

DATE 30 DAYS AFTER PUBLICATION IN THE FEDERAL REGISTER]. The 

final rule will respond to any OMB or public comments on the 

information collection requirements contained in this proposal.

C. Regulatory Flexibility Act

The Regulatory Flexibility Act (RFA) generally requires an 

agency to prepare a regulatory flexibility analysis of any rule 

subject to notice and comment rulemaking requirements under the 

Administrative Procedure Act or any other statute unless the 

agency certifies that the rule will not have a significant 

economic impact on a substantial number of small entities. 
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 district with a 

population of less than 50,000; and (3) a small organization 

that is any not-for-profit enterprise which is independently 

owned and operated and is not dominant in its field.

After considering the economic impact of this proposed rule 

on small entities, I certify that this action will not have a 

significant economic impact on a substantial number of small 

entities. We estimate that up to 7 of the 44 existing PCP are 

small entities which would not incur any impacts under these 

proposed amendments 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 from 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 tribal governments, in the 

aggregate, or to the private sector, of $100 million or more in 
80

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 reasonable number of 

regulatory alternatives and adopt the least costly, most costeffective, or least burdensome alternative that achieves the 

objectives of the rule. The provisions of section 205 do not 

apply when they are inconsistent with applicable law. Moreover, 

section 205 allows EPA to adopt an alternative other than the 

least costly, most cost-effective, or least burdensome 

alternative if the Administrator publishes with the final rule 

an explanation why that alternative was not adopted. Before EPA 

establishes any regulatory requirements that may significantly 

or uniquely affect small governments, including tribal 

governments, it must have developed under section 203 of the 

UMRA a small government agency plan. The plan must provide for 

notifying potentially affected small governments, enabling 

officials of affected small governments to have meaningful and 

timely input in the development of EPA regulatory proposals with 

significant Federal intergovernmental mandates, and informing, 

educating, and advising small governments on compliance with the 

regulatory requirements.

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 the 
81

aggregate, or the 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 obligations 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 

implications.” “Policies that have federalism implications” is 

defined in the Executive Order to include regulations that have 

“substantial direct effects on the States, on the relationship 

between the national government and the States, or on the 

distribution of power and responsibilities among the various 

levels of government.”
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 States, 

or on the distribution of power and responsibilities among the 

various levels of government, as specified in Executive Order 

13132. None of the affected facilities are owned or operated by 

State governments. Thus, Executive Order 13132 does not apply 

to this proposed rule.

In the spirit of Executive Order 13132, and consistent with 

EPA policy to promote communications between EPA and State and 

local governments, EPA specifically solicits comment on this 

proposed action from State and local officials.

F. Executive Order 13175: Consultation and Coordination with 

Indian Tribal Governments

Executive Order 13175, entitled “Consultation and 

Coordination with Indian Tribal Governments” (65 FR 67249, 

November 9, 2000), requires EPA to develop an accountable 

process to ensure "meaningful and timely input by tribal 

officials in the development of regulatory policies that have 

tribal implications." This proposed rule does not have tribal 

implications, as specified in Executive Order 13175. It will 

not have substantial direct effects on tribal governments, on 

the relationship between the Federal government and Indian 

tribes, or on the distribution of power and responsibilities 
83

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 proposed 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 the 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 proposal 
84

will result in the addition of alkaline scrubbers to certain 

kilns to reduce SO2 emissions. We estimate the additional 

electrical demand to be 6.9 million kWhr per year by the end of 

the 5th 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 Provisions, a 

source may apply to EPA for permission to use alternative test 

methods or alternative monitoring requirements in place of any 

required testing methods, performance specifications, or 

procedures in the final rule and amendments.

EPA welcomes comments on this aspect of this 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 regulation.

J. Executive Order 12898: Federal Actions to Address 

Environmental Justice in Minority Populations and Low-Income 

Populations

Executive Order 12898 (59 FR 7629 (Feb. 16, 1994)) 

establishes Federal executive policy on environmental justice. 

Its main provision directs Federal agencies, to the greatest 

extent practicable and permitted by law, to make environmental 

justice part of their mission by identifying and addressing, as 

appropriate, disproportionately high and adverse human health or 
86

environmental effects of their programs, policies, and 

activities on minority populations and low-income populations in 

the United States. EPA has determined that the proposed 

amendments will not have disproportionately high and adverse

human health or environmental effects on minority or low-income 

populations because they would increase the level of 

environmental protection for all affected populations without 

having any disproportionately high and adverse human health or 

environmental effects on any population, including any minority 

or low-income population. These proposed standards would reduce 
Amendments to Standards of Performance for Portland Cement 

Plants—page 87 of 110

emissions of PM, NOX, and SO2 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 63

Environmental protection, Air pollution 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 paragraphs (a)(1) and (a)(2) and adding

paragraphs (a)(3) and (a)(4); 

b. Revising paragraphs (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 REGISTER].

(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 uses a bag 

leak detection system, ESP predictive model, or a PM continuous 

emission monitoring system.

(3) Exceed 1.50 pounds of nitrogen oxide (NOX) 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 (SO2) emissions from a kiln for 

which construction, reconstruction, or modification commences 

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 SO2 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 cooler commenced 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

bag 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 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 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 provisions 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, 1971 
92

but on or before [INSERT DATE OF PUBLICATION IN FEDERAL 

REGISTER], the owner or operator must:

(i) Install, calibrate, maintain, 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 main 

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 after [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 

precipitator (ESP) used to control PM emissions according to the 

requirements in paragraph (o) 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. 

(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 

electrostatic 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 

section, and the alarm must be located such that it can be heard 

by the appropriate plant personnel.
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(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 

identified 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 system according to the sitespecific monitoring plan at all times. Each monitoring plan 
96

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 of the bag leak 

detection system, including how the alarm set-point will be 

established;

(iii) Operation of the bag leak detection system, 

including quality assurance procedures;

(iv) How the bag leak detection system will be maintained, 

including a routine maintenance schedule and spare parts 

inventory list;

(v) How the bag leak detection system output will be 

recorded and stored; and

(vi) Corrective action procedures as specified in 

paragraph (f)(3) of this section. In approving the sitespecific monitoring plan, the Administrator or delegated 

authority may allow owners and operators more than 3 hours to 

alleviate a specific condition that causes an alarm if the owner 

or operator identifies in the monitoring plan this specific 

condition as one that could lead to an alarm, adequately 

explains why it is not feasible to alleviate this condition 

within 3 hours of the time the alarm occurs, and demonstrates 
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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 

cause an increase in PM emissions;

(ii) Sealing off defective bags or filter media;

(iii) Replacing defective bags or filter media or 

otherwise repairing the control device;

(iv) Sealing off a defective fabric filter compartment;

(v) Cleaning the bag leak detection system probe or 

otherwise repairing the bag leak detection system; or

(vi) Shutting down the process producing the PM emissions.

(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) or 
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(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 daily 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 PUBLICATION IN 

FEDERAL REGISTER] must install, calibrate, maintain and operate 
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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 NOX emissions 

limit for a kiln in §60.62(a)(3) shall install, operate, 

calibrate, and maintain an instrument for continuously 

monitoring and recording the concentration by volume of NOX

emissions into the atmosphere.

(j) Each owner or operator subject to the SO2 emissions 

limit in §60.62(a)(4) for a kiln shall install, operate, 

calibrate, and maintain an instrument for continuously 

monitoring and recording the concentration by volume of SO2 

emissions into the atmosphere. If complying with the 

alternative 90 percent SO2 emissions reduction emission limit, 

you must also for continuously monitor and record the 

concentration by volume of SO2 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 Performance 
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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 NOX monitor shall be set at 125 

percent of the maximum estimated hourly potential NOX emission 

concentration that translates to the applicable emission limit 

at full clinker production capacity.

(2) The owner or operator shall conduct performance 

evaluations of each NOX 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 method 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 SO2 monitor must be set at 125 

percent of the maximum estimated hourly potential SO2 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 SO2 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 6, 6A, or 6C of 
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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 during 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 data, 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 data 
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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 NOX

emissions limit in §60.62(a)(3) or the SO2 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 

requirements 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 SO2 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 of 
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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 the 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 at 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, 
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shutdown, malfunction, except for monitoring system breakdowns, 

repairs, and calibration checks.

(n) You must monitor the performance of any ESP specified 

in paragraph (b)(2)(ii) of this section in accordance with the 

requirements 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 §60.62(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 baseline 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 Monitoring (CAM) 

Protocol for an Electrostatic Precipitator (ESP) Controlling 
105

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 

Monitoring.

(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 first 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 during 
106

which the model output values exceeded the applicable baseline 

levels, and the date, time, and description of 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: 

E (c Q )/(PK) 

s sd (Eq. 1) 
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Where: 

E = emission rate of particulate matter, kg/ metric ton (lb/ton) 

of kiln feed; 

Cs = concentration 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 FEDERAL 

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 follow 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 NOX and SO2 as the total of all 

hourly emissions data for a cement kiln in the preceding 30 
108

days, divided by the total tons of clinker produced in that kiln 

during the same 30-day period using Equation 2 of this section:

E (c Q )/(PK) 

s sd (Eq. 2) 

Where: 

E = emission rate of NOX or SO2, kg/metric ton (lb/ton) of 

clinker production; 

Cs = concentration of NOX or SO2, g/dscm (gr/dscf); 

Qsd = volumetric flow rate of effluent gas, dscm/hr (dscf/hr);

P = total kiln clinker production rate, metric ton/hr (ton/hr).; 

and

K = conversion factor, 1000 g/kg (7000 gr/lb).

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 agency 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 are 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 in 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